Available online at www.sciencedirect.com South African Journal of Botany 79 (2012) 173 – 240 www.elsevier.com/locate/sajb Conference Abstracts South African Association of Botanists (SAAB) – Annual Meeting 2012 Abstracts of papers and posters presented at the 38th Annual Congress of the South African Association of Botanists held at the University of Pretoria, Pretoria, 15-18 January 2012 The presenter of multi-authored papers is underlined ★ Awards made to students Plenary lectures CO2 as a driver of global change in African ecosystems W. Bond Botany Department, University of Cape Town, South Africa Savannas evolved under low atmospheric CO2 which favored C4 grasses over their C3 predecessors. Over the last century, CO2 has increased to levels exceeding those recorded in paleo-atmospheres over at least the last million years. In the coming century they are expected to increase to levels last seen in the Eocene, more than 30 Ma ago. These anthropogenic increases in CO2 are likely to have profound effects on African ecosystems and especially C4 grassy ecosystems. Here I review studies of the contributions of increasing CO2 to vegetation change in African ecosystems. Simulation studies, glasshouse experiments, and long term field experiments point to significant CO2 effects on woody plant expansion, especially in higher rainfall savannas. The future of the C4 grassy biomes in Africa looks very uncertain in a high CO2 world. Desertification, carbon sequestration and job creation: The science behind the Subtropical Thicket Restoration Project R.M. Cowling a, A. Mills b, A. Sigwela a, S. Pierce a, M. Van der Vyver a, C. Marais c a Restoration Research Group, Department of Botany, P.O. Box 77000, Nelson Mandela Metropolitan University, Port Elizabeth 6031, South Africa b Restoration Research Group, Department of Soil Science, Stellenbosch University, Private Bag X1, Matieland 7602, South Africa c Natural Resource Management, Department of Environment Affairs, Parliament Towers, 103–107 Plein Street, Cape Town 8000, South Africa Subtropical thicket ecosystems dominated by Portulacaria afra (spekboom) store amounts of carbon comparable to forest ecosystems that receive up to three times their annual rainfall. This remarkable finding – an outcome of SANBI's Conservation Farming project – led to the initiation of research on the potential to finance the restoration of degraded spekboom thicket via the emerging carbon economy. The research, which is funded by the Natural Resources Management Programme of the Department of Environment Affairs, was conceptualized as a monitoring and evaluation program, in order to facilitate social learning and adaptive management for catalyzing large-scale, biome-wide restoration in the private sector. This program was formalized as the Subtropical Thicket Restoration Project (STRP), a learning organization comprising managers and researchers. Here I describe a decade of biophysical research that has culminated in the validation of the world's first carbon sequestration project involving the restoration of a desertified ecosystem. The STRP has successfully catalyzed an initiative that is consistent with the South African government's commitment to create employment via a green economy. Regulation of carotenoid biosynthesis and its connection to the biogenesis and function of plastids J. Hirschberg Department of Genetics, Alexander Silberman Institute of Life Sciences, The Hebrew University of Jerusalem, Jerusalem 91904, Israel Carotenoid pigments are essential components of the photosynthetic apparatus and thus are present in all green tissues of plants. These molecules are synthesized within plastids from the central isoprenoid pathway by enzymes that are nuclear encoded. In addition to their primary functions in photosynthesis, carotenoids play essential roles in plant reproduction by furnishing flowers and fruits with distinct pigmentation and as precursors for volatiles and aroma compounds that attract animals. Two phytohormones, abscisic acid (ABA) and 0254-6299/$ -see front matter © 2012 SAAB. Published by Elsevier B.V. All rights reserved. doi:10.1016/j.sajb.2012.02.002 174 SAAB Conference Abstracts strigolactones, are produced from carotenoids. We are studying carotenoid biosynthesis and its regulation in flowers and fruits of tomato (Solanum lycopersicum), which has become a model system for chromoplast-containing plants. Over the years we have developed various genetic tools to decipher carotenogenesis in plants by cloning and analyzing genes that encode enzymes of the pathway. To this end, we have isolated novel mutations in tomato that alter pigmentation of flowers and fruit. Through characterization of these mutations we have identified new enzymes in the carotenoid biosynthesis pathway. Recent results from characterization of mutations demonstrated the importance of RedOx to the biosynthesis of carotenoids and revealed a link between carotenoid biosynthesis and plastid biogenesis. From botanical data to macroecological patterns in invasion ecology P. Pyšek Institute of Botany, Academy of Sciences of the Czech Republic, Průhonice & Department of Ecology, Faculty of Science, Charles University in Prague, Czech Republic Invasion ecology, as a field studying historical processes and their current outcomes, crucially depends on centuries of regional botanical tradition. The talk will explore how primary botanical data can be used to infer about macroecological patterns and processes of plant invasions at various scales, hence contributes to the invasion theory and our understanding of habitat invasibility, species invasiveness and spread, as well as factors determining these characteristics. Experiences with building national and continental databases of alien species in Europe, by using botanical literature and regional checklists will be also discussed. Metabolomics: a gateway to discoveries R. Verpoorte, N. Yuliana, H.K. Kim, Y.H. Choi Natural Products Laboratory, Institute of Biology Leiden, Leiden University, P.O. Box 9502, 2300 RA Leiden, The Netherlands Metabolomics has developed in a major tool in all types of research in the past decade. Functional genomics, plant resistance, quality control of food and botanicals, you name it. The basis of metabolomics is making unbiased observations with highly reproducible analytical tools, followed by a biostatistical analysis to find correlations between all the available data. That is a systems biology approach, which may lead to new discoveries. This can be illustrated by the identification of the active compounds in medicinal plants. By measuring the metabolome of different extracts, accessions or fractions of a medicinal plant and combining these data with those of biological activity, signals related to the compounds related to activity can be found. That may include prodrugs and synergy in case of in-vivo experiments. To be able to measure all metabolites present in e.g. a plant, we developed comprehensive extraction as a way to rapidly identify the active compounds in a plant. NMR-based metabolomics of the fractions obtained with this method and combining these data with adenosine receptor binding activity data allowed the identification of flavonoids as the active compounds in Orthosiphon stamineus leaves. A very different but quite exciting discovery we made through the NMR-based metabolomics was the Natural Deep Eutectic Solvents (NADES). The data we collected in NMRbased metabolomics made us to ask the question “why are a few very simple molecules always present in considerable and similar amounts in the spectra of any organism?” They must have a basic function in living cells. They include sugars, amino acids (e.g. proline, alanine, glutamine, asparagine), choline, and organic acids (e.g. malic, lactic, succinic acids). Sugars serve for storage and energy, the other compounds are in amounts that do not make sense to consider them only as metabolic intermediates. We found that mixtures of organic acids with bases form ionic liquids, whereas neutral solids may form deep eutectic solvents, e.g. sugars with choline or malic acid. NADES have a polarity like ethanol, and are excellent solvents for natural products, including DNA and proteins, often with orders of magnitude higher solubility than in water. In our hypothesis many cellular and physiological functions are connected with the occurrence of NADES in nature. Paper abstracts Efficacy and toxicity of thirteen plants leaf acetone extracts used in ethnoveterinary medicine in South Africa on the egg and larva of Haemonchus contortus M. Adamu a, V. Naidoo b, J.N. Eloff a a Phytomedicine Programme, Department of Paraclinical Sciences, Faculty of Veterinary Science University of Pretoria, South Africa b University of Pretoria Biomedical Research Centre, Pretoria, South Africa In this study thirteen plants leaf acetone extracts used traditionally in ethnoveterinary medicine in South Africa were evaluated using the egg hatch assay and the larval development test. Cytotoxicity of these plants was also evaluated using the MTT cellular assay. Extracts of three plant species i.e. Heteromorpha trifoliata, Maesa lanceolata and Leucosidea sericea had EC50 values of 0.62 mg/ml, 0.72 mg/ml and 1.08 mg/ml respectively for the egg hatch assay. Other plants with good anthelmintic activity include Clausena anisata; 1.08 mg/ml and Clerodendrum glabrum; 1.48 mg/ml. In the larval development test H. trifoliata extract was the best with EC50 of 0.64 mg/ml followed by L. sericea 1.27 mg/ml. The activities in the larval development test were generally lower in most plant species compared to the egg hatch assay. Based on the cytotoxicity results SAAB Conference Abstracts C. anisata was the least toxic with an LC50 of 171.86 μg/ml, while Cyathea dregei was the most toxic plant with an LC50 of 3.3 2 μg/ml. The selectivity index of the thirteen plants shows C. anisata as the best with a value of 95.48 and 83.02 for both assays, this was followed by H. trifoliata and L. sericea with values of 68.58, 66.44 and 47.69, 40.55 for both assays and plant species respectively. The plant species with the worst S.I was C. dregei with a value of 0.19 for both assays. The result of this study confirms a scientific basis for the folkloric claim of the natives of South Africa in the use of these plants for the treatment of helminthiasis in livestock. The possibility of finding a compound with good anthelmintic activity from the most efficacious and less toxic plants will be evaluated. Further study will involve the fractionation of selected plants and evaluating their anthelmintic activity. In vitro screening for acetylcholinesterase inhibition and antioxidant activity of medicinal plants from southern Africa E.A. Adewusi, V. Steenkamp Department of Pharmacology, School of Medicine, Faculty of Health Sciences, University of Pretoria, Private Bag X323, Arcadia 0007, South Africa Neurodegenerative disorders primarily affect the elderly population. Alzheimer's disease, the most common neurodegenerative disorder, is associated with a deficiency in levels of the neurotransmitter acetylcholine as well as increased generation of reactive oxygen species (ROS). The aim of the study was to determine the acetylcholinesterase inhibitory (AChEI) and antioxidant activity of the ethyl acetate and methanol extracts of 12 traditional medicinal plants used in the treatment of neurological disorders. AChEI activity was determined spectrophotometrically using the Ellman's colorimetric method. Antioxidant activity was carried out by determining the ability of the extracts to scavenge the 2,2-diphenyl-1-picryl hydrazyl (DPPH) and 2,2′-azinobis-3-ethylbenzothiazoline-6sulfonic acid (ABTS) radicals. The levels of total phenols, flavonoids and flavonols were determined quantitatively using spectrophotometric methods. AChEI was observed to be dosedependent. Lannea schweinfurthii (Engl.) Engl. and Scadoxus puniceus (L.) Friis & I. Nordal. root extracts showed the lowest IC50 value of 0.0003 mg/ml for the ethyl acetate extracts while Zanthoxylum davyi (I. Verd.) P.G. Watermann had the lowest IC50 value of 0.01 mg/ml for the methanol extracts in the AChEI assay. The roots of Piper capense L.f., L. schweinfurthii, Ziziphus mucronata Willd., Z. davyi and Crinum bulbispermum (Burm.f.) Milne-Redh. & Schweick. showed noteworthy radical scavenging activity and good AChEI activity. Five plants showed good antioxidant and AChEI activity. These findings support the traditional use of the plants for treating neurological disorders especially where a cholinesterase mechanism and ROS are involved. 175 Molecular characterization of chili leaf curl virus and satellite DNA associated with pepper in Oman A.M. Al-Zaidi, J. Khan Department of Crop Sciences, College of Agricultural & Marine Sciences, Sultan Qaboos University, P.O. Box-34, AlKhod, Sultanate of Oman Pepper (Capsicum annuum) is cultivated in the coastal region of Al-Batinah, A'Sharqiya and Dhofar regions in the Sultanate of Oman during the winter season to meet the high demand for fresh produce in the domestic market. To identify the causal agent of a widespread disease associated with infestations of the whitefly Bemisia tabaci (Genn.), leaves were collected from sweet pepper plants showing symptoms characteristic of the begomovirus disease in Al-Batinah and Dhofar during 2010 and 2011. Total nucleic acids were isolated from the pepper leaves and used as the template for Φ29 DNA polymerase amplification of begomoviral circular DNA. Putative full unit length begomoviral DNA multimers were digested with PstI and cloned into the plasmid vector pUC19. The complete nucleotide (nt) sequence was determined as 2758 base pairs (bp), indicative of a monopartite begomoviral genome. A comparison of the genome sequence for the ten field isolates examined indicated that they shared 98–99% nt identity. The virus from Oman was most closely related to ChLCV-Multan at 96% nt identity, a monopartite begomoviral isolate described previously from Pakistan. Based on the guidelines of the ICTV the Oman isolate has been designated ChLCV-Om and is considered a strain of ChLCV-Multan. A satellite DNA (DNA β), was amplified by polymerase chain reaction using degenerate primers and cloned, and the DNA sequence was determined. Analysis of the complete nt sequence of 1327 bp indicated that the DNA β shared 96% similarity with its closest relatives, which are TYLCV Al-Batinah DNA β molecules isolated from tomato in Oman. This is the first report of ChLCV from Oman and DNA β associated with the ChLCV-Om isolate. The ChLCV-Om and associated TYLCV Al-Batinah DNA β thus represent a begomovirus-complex at the Asian–Middle East crossroads that uniquely share geographical and genetic hallmarks of both. In vitro propagation and secondary metabolite production in Aloe arborescens: The role of aromatic cytokinins S.O. Amoo, A.O. Aremu, J. Van Staden Research Centre for Plant Growth and Development, School of Life Sciences, University of KwaZulu-Natal Pietermaritzburg, Private Bag X01, Scottsville 3209, South Africa A. arborescens is well known for its medicinal and horticultural values. Plant biotechnology offers an efficient tool for the production and modification of important plant secondary metabolites. A basic requirement for the transformation process is the development of a simple yet efficient propagation 176 SAAB Conference Abstracts protocol. The choice of plant growth regulators (PGR), especially cytokinins, remains a critical factor in developing an efficient micropropagation system. In the present study, we investigated the effects of five different concentrations each of seven aromatic cytokinins (6-benzyladenine, meta-topolin and their derivatives) on in vitro shoot regeneration and secondary metabolite production in A. arborescens. All the treatments produced adventitious shoots with high frequency ranging from 86.7 to 100%. The highest number of adventitious shoots produced per shoot-tip explant (7.3 ± 0.71) was observed in Murashige and Skoog (MS) medium supplemented with 5 μM benzyladenine riboside after six weeks of culture. Variable amounts of iridoids, phenolics and flavonoids were present in all the treatments. Unlike with most of the cytokinin treatments, no proanthocyanidin was detected in regenerated plants cultured on PGR-free MS medium. In general, higher antioxidant and radical scavenging activities were observed in regenerated shoots produced in cytokinin-containing media when compared to the PGR-free medium. Our findings indicate that exogenous supply of different types and concentrations of aromatic cytokinins during micropropagation markedly influences in vitro production of bioactive secondary metabolites. Phytoremediation of polychlorinated biphenyls (PCBs) contaminated soil by Chromolaena odorata (L) King and Robinson R.O. Anyasi a, H.I. Atagana b a Department of Environmental Sciences University of South Africa, Pretoria 0003, South Africa b Institute for Science and Technology Education, University of South Africa, Pretoria 0003, South Africa The ability of C. odorata propagated by stem cuttings and grown for six weeks in the greenhouse to thrive in soil containing different concentrations of PCB congeners found in Aroclor and transformer oil (TO), and to possibly remediate such soil was studied under greenhouse conditions. C. odorata plants were transplanted into soil containing 100, 200, and 500 μg g - 1 of Aroclor 1254 and 1260, and soil containing 100, 200, and 500 ml kg - 1 transformer oil (TO) in 1 L pots. The experiments were watered daily to maintain 70% moisture at field capacity. Parameters such as fully expanded leaves per plant, shoot length, leaf color as well as the root length at harvest were measured. C. odorata growth was differently affected by the different concentrations of transformer oil. The level of inhibition to plant growth increased with concentration. However, the Aroclor amended soil did not affect the plant. At the end of six weeks of growth, plants showed a diminished effect in TO amended soil to the parameters tested. Plant size was increased by 1.4, 0.46 and - 1.0% in 100, 200 and 500 mg/kg respectively. In Aroclor amended samples, 45.9, 39.4 and 40.0% were plant sizes at different concentrations. Such trend was observed in the leaf numbers and root length. Leaf color was pale green in TO samples but, middle green in Aroclor amended soils. The control sample has 43.3% increase in plant size which was not significant among the values in Aroclor treated soils, an indication that C. odorata could survive PCB contamination as to remediate it. The result of the on-going GCanalysis would be presented in the main paper and would be used to establish the extent of remediation. PRECIS, 35 years on R.H. Archer National Herbarium, South African National Biodiversity Institute, Private Bag X101, Pretoria 0001, South Africa Under the directorship of Bernard de Winter at the Botanical Research Institute in the 1970s, the then innovative National Herbarium, Pretoria (PRE) Computerised Information System (PRECIS) was planned and become operational. Encoding of 470 000 mainly southern African and type specimens began in June 1975 and was completed in December 1976. The system was maintained on a Burroughs 7800 mainframe at the Department of Agriculture. This first version was soon completely restructured and in April 1982 PRECIS II was implemented. Today, PRECIS is integral to most activities at PRE and NBG where it has expanded to more than 1 110 000 specimen records and more than 60 000 taxon name records. A pc based version, PRECIS.pc is used at NH but remains separate from PRECIS itself. Additionally, PRECIS.pc has been implemented at many smaller herbaria both within South Africa and 10 southern African countries as part of the 10 year SABONET project (1996 to 2005). We present a historical and critical review of intervening implementations of PRECIS on four different computer and software systems. At present we are preparing for the fifth migration on to the internationally acclaimed BRAHMS database (Botanical Research and Herbarium Management System) based at Oxford, England. It is time to ask the following questions: Who were the main role-players behind PRECIS? Did PRECIS achieve its initial expectations? What was the impact of PRECIS on herbarium management and research at PRE and NBG and within SANBI, and on botany in South Africa in general? Influence of six aromatic cytokinins on the growth, phenolic and pigment contents of micropropagated banana (Musa spp. AAA cultivar ‘Williams’) A.O. Aremu, M.W. Bairu, J.F. Finnie, J. Van Staden Research Centre for Plant Growth and Development, School of Life Sciences, University of KwaZulu-Natal Pietermaritzburg, Private Bag X01, Scottsville 3209, South Africa The effect of benzyladenine (BA) and five topolins (metaTopolin = mT; meta-Topolin riboside = mTR; meta-Methoxy topolin = MemT; meta-Methoxy topolin riboside = MemTR and meta-Topolin 9-tetrahydropyran-2-ylpurine = mTTHP) on the SAAB Conference Abstracts growth, phenolic and photosynthetic pigment contents of ‘Williams’ bananas were evaluated. Explants were cultured for 42 days on modified Murashige and Skoog media containing 10, 20 and 30 μM of the above aromatic cytokinins (CK). Using spectrophotometric methods, phenolic and pigment contents were quantified from the 50% methanol and acetone extracts, respectively. Analysis of growth parameters indicate that the use of 30 μM mT resulted in the highest shoot multiplication rate (7 shoots/explant). Shoot length and fresh weight per plantlet were significantly lower in all the treatments compared to the control. However, at 30 μM CK treatment shoot dry weights were significantly higher than the control, with the highest being treatment with MemT. The lowest abnormality frequency was observed in 10 μM mTR regenerants. Treatments with 10 μM mT (25.3 ± 4.98) and mTTHP (27.0 ± 3.30) had the highest number of roots/explant. These treatments stimulated significantly higher total phenolic content in aerial parts of the plantlets. Conversely, 30 μM mTTHP favored accumulation of the same secondary metabolites in the underground parts. Accumulation of these metabolites would probably enhance plant acclimatization. In terms of photosynthetic pigments (chlorophyll a, b and carotenoids), CK treatments brought no improvement in the regenerated plantlets. Studies on endogenous CK profiles and effect of the aromatic CKs on genetic stability are currently underway. Pollination of Aloe peglerae – An endangered endemic of the Magaliesberg Mountains, South Africa G. Arena, C. Symes, E.T.F. Witkowski School of Animal, Plant and Environmental Sciences, University of Witwatersrand, Private Bag 3, Johannesburg 2050, South Africa A. peglerae is a winter flowering succulent endemic to the Magaliesberg Mountains. It is listed as Endangered and is vulnerable to illegal collecting from the wild. The attractive inflorescence and the height of the raceme make it conspicuous to pollinators. Flowers produce nectar of low concentration (9.9%) and relatively high volumes (17.5 μl), hence we hypothesized that effective pollination is facilitated through aviannectar feeding only. Pollinator exclusion experiments were used to determine contributions to fruit and seed set by different pollinator guilds. Three treatments were applied to sixty ‘focal’ aloes; 1) control – open to all floral visitors, 2) bird exclusion – mesh cage allowing only insect visitors, and 3) total exclusion – fine mesh netting excluding all floral visitors. Average% fruit set with bird and total exclusions was low (12.1 and 5.3%, respectively), while control plants had by far the highest fruit set (40.4%, P N 0.05), suggesting that birds are the major pollinators for A. peglerae. Similarly, seed set per fruit under bird and total exclusion were also much lower (16.9 and 15.7%, respectively) than in control plants (38.3%; P b 0.0001). Finally, total seed production per plant was much lower in bird and total exclusions (497 and 322, respectively), compared with 177 the control (3868; P b 0.0001). Nectar production increased from morning to midday when feeding rates of birds were higher, resulting in nectar standing crop volume decreasing during the afternoon (28.8 μl). There was a slight increase in standing crop from the morning (29 μl) to midday (38.1 μl). However, nectar concentration remained constant through the day (9.7–10.2% w/w). Understanding the pollination biology of A. peglerae, together with information on its population demography, will contribute significantly to conserving this species. The germination and propagation potential of Securidaca longepedunculata Fresen O. Baloyi, R.B. Bhat, M.P. Tshisikhawe Department of Botany, University of Venda, Thohoyandou 0950, South Africa S. longepedunculata Fresen. is commonly known as the violet tree of the polygalaceae family. S. longepedunculata as a medicinal plant, is used in both Western and Southern Africa to treat a wide range of ailments. Because of its many uses, the plant is now faced with unsustainable harvesting pressure which in the long run may lead to the plant being extinct. Therefore, there is a need to implement cultivation tools to save this valuable, medicinal plant. In this study, we studied the germination potential of S. longepedunculata under three germination factors; temperature, light and soil depth. Seeds were subjected to three pre-treatment; mechanical scarification, soaking in distilled water overnight and soaking in 3.5% m/v domesticated bleach for 60 min. Optimal temperatures for seed germination were 20 °C and 30 °C. With regard to soil depth, high germination percentage was obtained at soil depth of 4 cm, with seedling emergence of 30%. Both depths 2 cm and 8 cm had seedling emergence of 10% respectively and only 3% at 6 cm. No seedlings emerged at 10 cm level. Based on the findings, it is concluded that soil depth has an effect on seedling emergence and S. logepedunculata responds well to soil depth of 4 cm. The effect of temperature and relative humidity on Acacia mearnsii pollen viability S.L. Beck-Pay, K. Koen Institute for Commercial Forestry Research, P.O. Box 100281, Scottsville 3209, Pietermaritzburg, South Africa A. mearnsii (black wattle) is a commercially important forestry species in South Africa, grown for its timber as well as its bark. It is, however, also considered to be an alien invader of indigenous vegetation and for this reason the production of a sterile variety would be highly desirable for commercial forestry in South Africa. Previous research on crosses between diploid and tetraploid parent plants to produce triploid progeny 178 SAAB Conference Abstracts has resulted in poor seed set. One possible barrier preventing seed set could be the viability of the pollen used in the cross pollination operations. Thus a study was conducted to test the pollen viability. In vitro agar media germination tests (ACIAR and Brewbaker and Kwack media) together with vital stain tests (Sigma® DAB peroxidase and pphenylendiamine) were used to test pollen germination and viability of A. mearnsii pollen. These were then compared to in vivo pollen germination on the stigma. Results showed that the vital stain tests gave significantly (P b 0.05) higher pollen viability (59.53 and 60.67%) than the agar germination tests (11.92 and 24.50%) and were more in agreement with the results from the pollen germination rate on the stigma (94.59%). In 2011 pollen was subjected to various temperature and relative humidity combinations, to simulate conditions recorded within the isolation bags being used in the 2010 flowering season. The results from this study together with a comparison of pollen viability results across three seasons (2009, 2010 and 2010) will be discussed. Anticancer activity of certain herbs and spices on the cervical epithelial carcinoma (HeLa) cell line What drives invasion success on Robben Island, South Africa? B.S. Bezeng a,b, O. Maurin a,b, K. Yessoufou a,b, M. Van der Bank a,b a African Centre for DNA Barcoding, University of Johannesburg, P.O. Box 524, Auckland Park 2006, Johannesburg, South Africa b Department of Botany and Plant Biotechnology, University of Johannesburg, P.O. Box 524, Auckland Park 2006, Johannesburg, South Africa Robben Island was declared a world heritage site in 1999. It lays 11 km from the port of Cape Town with a surface area of about 500 ha. Natural ecosystems on the Island have been severely degraded and altered by the introduction of various fauna and alien vegetation. The woody shrub component of the original West Coast Strandveld vegetation has been eradicated and the diversity of the herbaceous component has been reduced, with major invasion by alien plant species occurring since 1933 with apparent little invasion prior to this period. Currently a new management plan for the natural environment of Robben Island has been developed. The main goal of this study is to determine what drives invasion success on Robben Island. Our main results will be discussed. D. Berrington, N. Lall Department of Plant Sciences, University of Pretoria, Pretoria 0002, South Africa Acetone extracts, of nine herbs and one spice, were prepared and tested for their cytotoxic ability, in vitro, against a noncancerous African green monkey kidney (Vero) cell line and an adenocarcinoma cervical cancer (HeLa) cell line. The plants studied were: Origanum vulgare (Oregano), Rosmarinus officinalis (upright rosemary and groundcover rosemary), Lavendula spica (Lavender), Laurus nobilis (Bay leaf), Thymus vulgaris (Thyme), Lavendula × Intermedia (Margaret Roberts Lavender), Petroselinum crispum (Curly leaved parsley), Foeniculum vulgare (Fennel) and C. annuum (Paprika). Of these plants only L. nobilis and O. vulgare exhibited pronounced cytotoxic effects on the HeLa cell line. Dose-dependent studies revealed 50% inhibitory concentrations (IC50) values of 34.46 μg/ml and 126.3 μg/ml on the HeLa cell line and IC50 of 124.1 μg/ ml and 163.8 μg/ml on the Vero cell line for L. nobilis and O. vulgare respectively. The cytotoxic ability was measured using XTT (sodium 3′-[1-(phenyl amino-carbonyl)-3,4-tetrazolium]-bis-[4-methoxy-6-nitro] benzene sulfonic acid hydrate) colorimetric assay. Antioxidant activity was determined using DPPH (1,1-Diphenyl-2-picryl hydrazyl). Both L. nobilis and O. vulgare showed good free radical scavenging capability with IC50 values of 30.8 5 μg/ml and 26.43 μg/ml respectively. Light microscopy (eosin and hematoxylin staining) and confocal microscopy (Hoechst 33342, acridine orange and propidium iodide staining) were used to evaluate the mechanism of action of the acetone leaf extracts of L. nobilis and O. vulgare. Progress towards DNA barcoding of invasive species in South Africa J.S. Boatwright a,b, M.T. Sethusa c, O. Maurin c, P. Ivey d, M. Hamer e, M. Van der Bank c a Compton Herbarium, South African National Biodiversity Institute, Private Bag X7, Claremont 7735, Cape Town, South Africa b Department of Botany and Plant Biotechnology, University of Johannesburg, P.O. Box 524, Auckland Park 2006, Johannesburg, South Africa c African Centre for DNA Barcoding, University of Johannesburg, P.O. Box 524, Auckland Park 2006, Johannesburg, South Africa d Early Detection and Rapid Response Unit, South African National Biodiversity Institute, Private Bag X7, Claremont 7735, Cape Town, South Africa e Biosystematics Division, South African National Biodiversity Institute, Private Bag X101, Pretoria 0001, South Africa South Africa's rich biodiversity, with ca. 20 456 species, is under constant threat mainly through agriculture, urbanization, habitat loss and encroachment of alien invasive species. More than ca. 660 naturalized plant species are currently known to be contributing to the widespread transformation of once pristine habitats in the country. Furthermore, an array of invasive animal species has also established feral populations. The early detection of invasive species and rapid response for eradication rely on accurate species level identification. This is SAAB Conference Abstracts often difficult as, outside their native range, there is a lack of herbarium and museum records, regional specific literature and expertise to aid in the identification of these species. In light of the challenges opposing accurate identification, alternative solutions need to be explored. DNA barcoding is one such tool that may aid in the identification of unknown material (especially when only incomplete material is available). This requires the use of short, highly informative DNA regions to discriminate between species. This lecture reports on a collaborative project between the Early Detection and Rapid Response Programme of the Working for Water Programme and South African National Biodiversity Institute (SANBI) and the African Centre for DNA Barcoding (ACDB) at the University of Johannesburg, funded by the Natural Resource Management Programme (Department of Environmental Affairs) which was started in August 2011. This project will form part of the International Barcode of Life Project (iBOL) and aims to collect invasive plant and animal samples in South Africa as well as South African species known to be invasive elsewhere in the world over an eight month period for DNA barcoding. The team consists of, apart from the co-ordinators, seventeen collaborators from 10 universities and research institutions in the country. Twenty-four recent graduates have been appointed at many of these institutions to undertake the collection and processing of samples for DNA barcoding. The in vitro inhibitory effect of Ptaeroxylon obliquum (Thunb.) Radlk. on adhesion of Candida albicans to human buccal epithelial cells (HBEC) F.S. Botha, C. Van Wyk, V. Bagla, J.N. Eloff Phytomedicine Programme, Department of Paraclinical Sciences, Faculty of Veterinary Science, University of Pretoria, Private Bag X04, Onderstepoort 0110, South Africa Candidal adherence to human buccal epithelial cells (HBEC) is the critical initial step in the pathogenesis of oral candidiasis, which may eventually lead to a systemic infection. Since the ability of C. albicans to form a germ tube and hyphae is an indication of replication and growth, its adherence to HBEC can be seen as a step in the colonalization of buccal epithelial cells in oral candidiasis, because the organisms cannot be removed by natural cleaning mechanisms' in the oral cavity. The ability of C. albicans standard strain (ATCC 10231) and two clinical isolates to adhere to healthy buccal epithelial cells (HBEC) in the presence of P. obliquum (Thunb.) Radlk., a medicinal plant used for several pharmaceutical purposes, were examined. Leaves of P. obliquum were harvested, dried and ground to powder. Extract of powdered leaves of P. obliquum were extracted with acetone at room temperature and 250 mg/ml P. obliquum acetone leaf extract was used as the starting concentration for the subsequent study. P. obliquum acetone leaf extract possessed antifungal activity toward C. albicans standard strain (ATCC 10231) and two clinical isolates. Adhesion of P. obliquum acetone leaf extract to HBEC was concentration 179 dependent and exhibited marked inhibitory effect on the ability of C. albicans strains to adhere to healthy buccal epithelial cells which were evident at higher concentrations. Light microscopy images showed that P. obliquum acetone leaf extract had an effect on the adhesion of C. albicans to HBEC. Where no inhibitory effect was observed, hyphae formation or germ tube formation (budding) was evident. In some cases it was observed that the C. albicans cells were destroying the ultra structure of the epithelia cells. This study shows the presence of substances in P. obliquum acetone leaf extracts with potential inhibitory effect on the adhesion of C. albicans to HBEC. Volatile emissions of Puccinia triticina infected wheat and its effect on uninfected wheat seedlings H.D. Castelyn, B. Visser, Z.A. Pretorius Department Plant Sciences, University of the Free State, P.O. Box 339, Bloemfontein 9300, South Africa Plants emit a vast array of different volatile organic compounds to which surrounding plants can respond. Recent research indicated a putative volatile signaling event between leaf rust (P. triticina) infected and uninfected wheat (T. aestivum). In the current project uninfected wheat was exposed to volatiles emitted by leaf rust infected wheat in a continual air flow system. Volatile exposure was done for different combinations of susceptible (Thatcher) and resistant (Thatcher + Lr9) wheat lines. The induction of a plant defense response in the uninfected wheat was confirmed on phenotypical, biochemical (β-1.3-glucanase activity) and gene expression (PR2 gene) levels. This defense activation in the exposed uninfected plants could be attributed to the released volatiles. Volatile profiles emitted by the infected wheat were determined and the results will be discussed. Identification, pathogenicity and population diversity of a new stem canker pathogen in the Cryphonectriaceae on Rapanea melanophloeos in South Africa S. Chen a, M.J. Wingfield a, F. Roets a, J. Roux a a DST/NRF Centre of Excellence in Tree Health Biotechnology (CTHB), Forestry and Agricultural Biotechnology Institute (FABI), Department of Microbiology and Plant Pathology, Private Bag X20, University of Pretoria, Hatfield, Pretoria 0028, South Africa b Department of Conservation Ecology and Entomology, Stellenbosch University, Stellenbosch 7600, South Africa R. melanophloeos (Myrsinaceae), commonly known as Cape Beech, is native to Africa and forms an important component of Afro-montane forests. During disease surveys in the Western Cape Province of South Africa, a serious stem canker disease on R. melanophloeos trees was observed in the Harold Porter National Botanic Garden. Infection on the trees often results in the death of branches and entire stems above the 180 SAAB Conference Abstracts cankers. Fruiting structures typical of fungi in the Cryphonectriaceae were observed on the surfaces of cankers. The aim of this study was to identify the causal agent of this disease and obtain information on its possible origin. Multiple gene analyses of the partial LSU and ITS nuclear ribosomal DNA, and two regions of the β-tubulin gene, showed that the fungus represents a previously undescribed genus and species in the Cryphonectriaceae. Phylogenetic analyses, as well as morphological comparisons suggest that it is most closely related to the genus Microthia. Stem inoculations indicated that the fungus is an aggressive pathogen of R. melanophloeos trees, with the ability to kill inoculated stems within six weeks. Based on vegetative compatibility groups (VCGs), the diversity of the pathogen in the Harold Porter National Botanic Garden is low, suggesting that it may have been introduced from outside the area where it is currently found. Medicinal orchid research – A South African perspective M. Chinsamy, J.F. Finnie, J. Van Staden Research Centre for Plant Growth and Development, School of Life Sciences, University of KwaZulu-Natal Pietermaritzburg, Private Bag X01, Scottsville 3209, South Africa Orchidaceae, the largest Angiosperm family, has a worldwide distribution of an estimated 35 000 species and 796 genera. Approximately 75% of the ± 1500 species occurring in southern Africa are endemic to the region and occupy very restricted distribution ranges. The relatively small number of species used in African traditional practices (± 49 species) may represent a more refined list of the most used species and/or genera. Generally, orchids are fiercely protected on the basis that they are rare and under threat from excessive collection. However, earlier threats such as collection for cultivation and horticulture and more recent threats such as loss of habitat and urbanization pose more of a risk to orchid populations. The conservation status of most medicinally used orchid species are Least Concern and could either reflect a negligible impact by collection for medicinal uses or it could indicate a lack of knowledge, or both, on such orchids. One of the gaps in our knowledge of South African orchids is the ethnobotanical, pharmacological and phytochemical usages of medicinal orchids. Understanding the usefulness of, and possible threats to, traditionally used orchid species would enable increased protection of these orchids and their habitats. Factors influencing use, distribution and the conservation status of medicinally used orchids will be addressed, together with a summary of the pharmacological and phytochemical assessments of some South African exploited orchid species. Floristic comparison of the northern and southern KwaZulu-Natal Drakensberg P. Cingo, G.V. Cron School of Animal, Plant and Environmental Sciences, University of Witwatersrand, Private Bag 3, WITS 2050, South Africa The KwaZulu-Natal Drakensberg forms part of the Drakensberg Alpine Centre above 1800 m, which is renowned for its species richness and high levels of endemism. Within the KZN Drakensberg two regions have been recognized: the south-east facing southern region and northern region with a north-east aspect and their floras are expected to be different. The aim of the study was to compare the northern KZN Drakensberg to the southern KZN Drakensberg floristically and to add to the knowledge of the flora of the northern KZN Drakensberg by collecting in a relatively under collected region. The PRECIS data set was used (supplemented with Ezemvelo KwaZulu-Natal Wildlife data) and a floristic comparison was done on family, genera and species composition. The composition of the top ten families was found to be very similar, but they differ in ranking except for the two largest families Asteraceae and Poaceae and three largest genera: Helichrysum, Senecio and Erica. The northern KZN Drakensberg appears to be more diverse with 1692 species compared to the southern Drakensberg which supports 1284 species above 1800 m. The southern KZN Drakensberg has, however been more thoroughly studied and has a greater number of collections compared to the northern KZN Drakensberg. Results from the chi-squared test show no significant difference between northern and southern KZN Drakensberg flora. 557 specimens, including 321 species in 170 genera and 59 families were collected from the Injisuthi region (northern KZN Drakensberg); with majority of collections in the altitudinal zone(s) 1800–1900 m and 1900–2025 m. Two new species were added to the known flora: Aspilia natalensis (Asteraceae) and Bothriochloa insculpta (Poaceae). Most plants were noted to flower in latespring to early/mid-summer. Ganoderma root rot: The scourge of Jacaranda mimosifolia in the “City of Jacarandas” M.P.A. Coetzee a, V.G. Muthelo b, M.J. Wingfield b, B.D. Wingfield b a Department of Genetics, Forestry and Agricultural Biotechnology Institute (FABI), University of Pretoria, Pretoria, South Africa b Department of Microbiology, Forestry and Agricultural Biotechnology Institute (FABI), University of Pretoria, Pretoria, South Africa Pretoria is adorned by thousands of J. mimosifolia trees. The city is rightly referred to as the “City of Jacarandas”, and covered during spring in a cloud of purple. Large numbers of these trees are dying in the suburb of Brooklyn due to a root and butt rot disease apparently caused by a species of Ganoderma. Fruiting bodies of Ganoderma resembling those in the “Ganoderma lucidum” complex are commonly found at the bases of dying trees every year after the onset of rain in spring SAAB Conference Abstracts and early summer. The “G. lucidum” complex includes several paraphyletic groups that are considered to represent different species with similar morphology; the true identity of the fungus causing the disease on Jacaranda trees is therefore unknown. The aim of this study was to characterize the species of Ganoderma that is found on Jacaranda trees dying from this root rot disease based on morphological characteristics and DNA sequence comparisons. Basidiocarps were collected from infected trees and their morphology was examined. Fungal isolations were made and cultural characteristics including growth habit, color and presence of chlamydospores were determined. DNA was extracted from the isolates and sequences obtained for the ITS regions (ITS-1, 5.8S gene and ITS-2), the IGS-1 region as well as the mitochondrial small subunit (mtSSU) gene. Morphological observations revealed that all of the isolates represented a species that was similar to those in the G. lucidum complex. DNA-based phylogeny confirmed that these isolates are closely related to G. lucidum. The gene phylogenies were, however, not congruent. Although a specific identification could not be made, the results of this study show that G. lucidum is a phylogenetically variable species complex and that the Ganoderma sp. commonly found associated with root rot disease of Jacaranda trees in Brooklyn resides in G. lucidum sensu lato. Attenuation of in vitro oxidative stress by polyphenolic-rich fractions of Burkea africana and Syzygium cordatum W. Cordier a , M. Gulumian b, A.D. Cromarty a, V. Steenkamp a a Department of Pharmacology, Faculty of Health Sciences, School of Medicine, University of Pretoria, P.O. Box X323, Arcadia 0007, Pretoria, South Africa b Department of Toxicology, National Institute for Occupational Health, P.O. Box 4788, Johannesburg 2000, South Africa Excessive production of ROS and free radicals in cells results in oxidative stress, a state which is involved in the etiology of diseases such as diabetes, neurodegeneration and cardiomyopathy. Antioxidant supplementation has been suggested as a prophylactic measure to control disease progression. Due to potential toxicity with synthetic antioxidant usage natural alternatives are becoming ever-popular. B. africana Hook.F (Fabaceae) and S. cordatum Hochst. ex C. Krauss (Myrtaceae) are both used ethnomedically for oxidative stress-related diseases. Plant extracts were fractionated through liquid–liquid extraction and assessed for polyphenolic content, antioxidant activity, inherent cytotoxicity and potential to reverse oxidative stress-induced parameters. Polyphenolic content was higher in B. africana (90.88 and 105.71 mg/g GAE and RE, respectively) than S. cordatum (43.36 and 49.80 mg/g). Cytotoxicity assessed through neutral red uptake was apparent for B. africana and S. cordatum in 3T3-L1 pre-adipocyte (IC50 = 24.3 μg/ml and 25.0 μg/ml, respectively) and C2C12 myoblast (13.9 μg/ ml and 20.5 μg/ml) cell lines, but not in normal human dermal fibroblasts and 48 h PMA-stimulated U937 monocytic cells 181 (N100 μg/ml). Antioxidant activity was found to be greater for S. cordatum when using the TEAC and DPPH assays (2.03 and 2.18 TE, respectively) than for B. africana (2.46 and 2.98). Both plants decreased the oxidative stressparameters induced by AAPH in terms of cytotoxicity, ROS formation, apoptosis and lipid peroxidation. S. cordatum elicited the most potent decrease in ROS formation (N 80% at 2.5 μg/ml). B. africana had the greatest anti-apoptotic effect, reducing caspase-3 activity by 40% at 20 μg/ml. B. africana and S. cordatum had similar activity in attenuating lipid peroxidation with 206.7% and 195.9% reduction at 20 μg/ml, respectively. The usage of these polyphenolic-rich fractions may be beneficial, in the treatment or prevention of oxidative stressrelated disorders. Better late than never? The high cost of self-incompatibility in Aloe maculata (Asphodelaceae) R.J. Cozien, S.D. Johnson School of Life Sciences, University of KwaZulu-Natal Pietermaritzburg, Private Bag X01, Scottsville 3209, South Africa Close to half of all flowering plant species show reduced reproductive success following self-pollination. This was long assumed to be achieved primarily through self-incompatibility mechanisms acting in the stigma or style to prevent germination of self pollen or successful growth of pollen tubes to the ovary. A few studies have shown, however, that even after self-pollen tubes penetrate the ovules, fecundity may be similarly reduced. Because of the high reproductive cost of disabled or aborted ovules, such late-acting self-incompatibility mechanisms should occur less frequently. To establish the relative importance of the different mechanisms, we investigated the breeding system of A. maculata, a South African succulent from a family in which self compatibility known but largely uncharacterized. Hand pollinations with self and cross pollen revealed very high levels of self incompatibility. Pollen chase experiments following cross pollination 24 h after self pollination indicated that self pollen usurps ovules. This was supported by a significant reduction in fecundity after hand pollination with mixtures of self and cross pollen relative to pollination with only cross-pollen. Hand pollinations with mixtures of cross and self, and cross and dead pollen showed that reduced fecundity does not result from stigma clogging by self pollen. Examination of pollen germination and tube growth using fluorescence and light microscopy confirmed that most ovules are fertilized within 24 h of pollination with either self or cross pollen. Pollinator exclusion completely prevented fruit set. Open-pollinated flowers had similar fruit and seed set to intact flowers supplemented with cross pollen, but both were less successful than flowers which received only cross-pollen, indicating that pollen quality limits reproductive success in natural populations. Further investigations are required to establish whether reduced fecundity following self pollination results from lateacting self-incompatibility or early inbreeding depression. 182 SAAB Conference Abstracts Understanding the transcriptional regulation of the Eucalyptus cellulose synthase1 gene N.M. Creux a,b, M. Ranik a,b, M.H. De Castro a,b , A. Spokevicius c, G. Bossinger c, C. Maritz-Olivier a, A.A. Myburg a,b a Department of Genetics, University of Pretoria, Pretoria 0002, South Africa b Forestry and Agricultural Biotechnology Institute (FABI), University of Pretoria, Pretoria 0002, South Africa c Department of Forest and Ecosystem Science, Melbourne School of Land and Environment, University of Melbourne, Water Street, Creswick, Victoria 3363, Australia Cellulose is a highly abundant biopolymer found in plant cell walls and has received considerable attention from various industries due to its unique molecular characteristics. Cellulose is deposited into plant cell walls by a large cellulose synthase (CesA) protein complex embedded in the cell membrane. The CesA proteins within this complex differ depending on whether primary or secondary cell walls are being deposited. While many studies have focused on the characterization of this enzyme and its biosynthetic pathway, there are few studies on the spatiotemporal regulation of the corresponding genes. We aimed to identify the promoter regions that interact with the transcription factors and modulate the expression of the Eucalyptus grandis CesA1 gene. We performed an in silico analysis on the promoters of six Eucalyptus CesA gene family members and identified a number of highly conserved cis-elements. The positions of these conserved elements allowed for targeted truncation of the EgCesA1 promoter. β-glucuronidase reporter-gene analysis in Arabidopsis and Eucalyptus enabled us to assign putative functions to some of the conserved regions. We also identified regions in the promoter that may contain novel elements necessary for EgCesA1 expression as they influenced β-glucuronidase expression but contained no known cis-elements. Several previously identified transcription factors are known to regulate CesA genes and we have cloned these to test which regions of the promoter these proteins bind. We are also screening the functional promoter regions against a cDNA expression library to identify novel proteins which may bind to the CesA1 promoter. Pairing regions of promoter sequence with transcription factors that binds them will aid in completing the regulatory model for this gene's promoter. This information will be useful on a fundamental level to understand the transcriptional control of cellulose biosynthesis in trees, as well as being applicable to future biotechnology approaches to enhance cellulose production. On the wings of butterflies: unique floral morphology and flower orientation promotes cross-pollination in Gloriosa superba R.J. Daniels, C.I. Peter Department of Botany, Rhodes University, Grahamstown 6140, South Africa G. superba L. (Colchicaceae) has conspicuous, brightly colored crimson and yellow flowers with reflexed and inverted tepals. Butterflies and sunbirds have been reported to visit the flowers but little work has been done to investigate the pollination biology of this species. In this paper, the identity of pollinators was investigated. In addition, measurements of stigma and pedicel orientations, nectar concentration and volume measurements and pollinator observations were used to test a number of hypotheses regarding the direction from which pollinators approach the flowers and the orientation of the stigma. It was hypothesized that (a) arriving pollinators would approach from clearings, (b) flowers would project toward clearings by pedicel orientation (c) stigmas would be orientated toward clearings to increase the likelihood of cross-pollination and (d) there is stigma–anther spatial separation to limit selfing. Results indicated that G. superba is specialized for butterfly pollination. Eronia cleodora is by far the most common visitor, although sunbirds occasionally visit in gardens but they are unlikely to be important pollinators. G. superba is one of the few known angiosperms that loads its pollen onto the wings of its pollinator. Anthers are separated from stigmas horizontally but overlap vertically. There was support for pedicel orientation away from vegetation and stigma orientation toward clearings to intercept incoming pollinators. Pollinator observations of tepal position corresponding to the sequence in which tepals were visited also support this hypothesis. Few butterflies visited N1 tepal/flower or N 1 flower/patch indicating potentially high outcrossing rates. The additive and synergistic antimicrobial effects of frankincense and myrrh – Essential oils from the predynastic period S. De Rapper a, S.F. Van Vuuren a, G.P.P. Kamatou b, A.M. Viljoen b a Department of Pharmacy and Pharmacology, Faculty of Health Sciences, University of the Witwatersrand, 7 York Road, Parktown 2193, South Africa b Department of Pharmaceutical Sciences, Faculty of Science, Tshwane University of Technology, Pretoria 0001, South Africa The historical use of frankincense and myrrh essential oils date back to biblical times, however, very little is known of their antimicrobial effects when used in combination. This study investigated the in vitro antimicrobial activity between three essential oil samples of frankincense (Boswellia rivae, Boswellia neglecta, Boswellia papyrifera) and two essential oil samples of myrrh (Commiphora guidotti and Commiphora myrrha) independently and in combination against various micro-organisms. When examined independently, it was noted that generally Cryptococcus neoformans and Pseudomonas aeruginosa often appeared to be the most susceptible microorganisms against oils both of Boswellia and Commiphora spp. with noteworthy minimum inhibitory concentration SAAB Conference Abstracts (MIC) values varying between 0.50 and 1.50 mg/ml. When assayed in various combinations, the frankincense and myrrh oils displayed synergistic (11.11%), additive (41.67%) and non-interactive properties (45.95%), with no antagonism noted. When investigating different ratio combinations against the pathogen Bacillus cereus, the most favorable combination observed was between Bacillus papyrifera and C. myrrha. The GC–MS showed that the oils are chemically diverse. Major compounds for C. myrrha were furanogermacrene (15.90%) and furanoeudesma-1.3-diene (44.30%), present only as minor components in C. guidotti. Major compounds for C. guidotti were (E)-β-ocimene (52.60%) and α-santalene (11.10%) and (E)-α-bisabolene (16.00%). α-Pinene (36.10–67.70%) was present in high concentrations in both B. rivae and B. neglecta. Other major compounds for B. rivae include σ-3-carene (12.20%) and limonene (12.00). One other major compound (terpinen-4-ol at 11.30%) was detected for B. neglecta and only one major compound (octyl acetate at 64.80%) was predominant for B. papyrifera. The historical and antimicrobial importances of these oils prove to be extremely promising when examined both independently and in combination. Probabilistic approaches to inferring plant extinctions from herbarium records K.J. Duffy School of Life Sciences, University of KwaZulu-Natal Pietermaritzburg, Private Bag X01, Scottsville 3209, South Africa The probability and time of extinction of taxa are often inferred from statistical analyses of herbarium records. Such spatially explicit, temporally aggregated data may be useful for identifying historical sighting clusters of endangered taxa in space and time. Identification of such sighting clusters can help highlight changes in the historical recording of endangered taxa. I used two methods to identify sighting clusters in historical records: the Ederer–Myers–Mantel (EMM) test and the space–time permutation scan (STPS). I applied these methods to the spatially explicit sighting records of three 3 nationally endangered orchids from the Republic of Ireland: Cephalanthera longifolia, Hammarbya paludosa, and Pseudorchis albida. Results show that the STPS is a more flexible statistical tool with sparse historical record data. This is because the STPS can identify regions that contain sighting clusters because it uses a flexible scanning window (defined by cylinders of varying sizes that move over the study area and evaluate the likelihood of clustering), and it identifies regions with high and regions with low rates of historical sightings. I show that, coupled with other probabilistic methods to infer extinction, the STPS analyses can be used to detect sighting clusters of endangered species that may be related to regions of extirpation and under-recording and may assist in the categorization of threat status. 183 Variation in biological activities of leaf extracts of 42 Combretum molle plants collected from different areas in Gauteng and Mpumalanga J.N. Eloff, G. Würger Phytomedicine Programme, Faculty of Veterinary Science, University of Pretoria, South Africa C. molle is an important medicinal plant that is used widely for many indications in several countries in Africa. Combretum species are also included in the 50 most important medicinal plants in the African Herbal Pharmacopoeia. One of the major problems in using medicinal plants that are collected in nature is uncertainty on the variation in biological activity. We investigated the antibacterial activity of acetone leaf extracts of 42 C. molle plants collected in different areas in the northern parts of South Africa against Escherichia coli and Staphylococcus aureus using a twofold serial dilution microplate method. Because other parts of the Combretaceae contain high tannin concentrations we also determined the tannin content of plants to determine if there is a correlation. In general although there were some differences in the chemical composition of different extracts and the tannin content, there were little differences in antibacterial activity of plants collected in different areas. The average minimum inhibitory concentration against E. coli was 220 μg/ml (SD 70) μg/ml and against S. aureus was 399 (SD 162) μg/ml. The inverse correlation between tannin content and antibacterial activity was low with R 2 values of 0.183 (E. coli) and 0.286 (S. aureus). When cultures were incubated for 120 min to determine if the activity was mainly bacteriostatic or bactericidal there was very little decrease in the activity. The results indicate that at least in the case of this species environmental factors do not play a major role in the antibacterial activity and that information obtained for a plant can be extrapolated to other plants. There were some cases where much higher activities were obtained. If this higher activity is maintained it indicates that it may be feasible to search for chemotypes to propagate for the delivery of high activity plant extracts. Projections of regional climate change over southern Africa – The water balance in a warmer climate F.A. Engelbrecht a,b a CSIR Natural Resources and the Environment – Climate Studies, Modelling and Environmental Health, Pretoria 0001, South Africa b Climatology Research Group, GAES, University of the Witwatersrand, South Africa A variable-resolution global atmospheric circulation model is used to downscale the projections of six different coupled climate models that contributed to Assessment Report Four (AR4) of the Intergovernmental Panel on Climate Change (IPCC) to high resolution (about 0.5° in latitude and longitude) over 184 SAAB Conference Abstracts southern Africa. All the simulations are for the A2 (business as usual) emission scenario and for the period 1961–2100. The variable-resolution model used is the conformal-cubic atmospheric model (CCAM) of the Commonwealth Scientific and Industrial Research Organisation (CSIRO) in Australia. In these simulations, CCAM was integrated using a static description of the land-surface (e.g. fields such as the vegetation type and surface albedo did not vary at an inter-annual time-scale). Additionally, simulations are shown where the land-surface responded dynamically to the changing climate. For these simulations, CCAM was applied coupled to the CABLE (CSIRO Atmosphere–Biosphere Land-Exchange) dynamic landsurface model. The southern African region is projected to warm rapidly during the 21st century, at about twice the global rate of temperature increase. For large parts of the interior regions of southern Africa, the climate for the period 2071–2100 is projected to be 4 °C to 6 °C warmer than the climate of the baseline period 1961–1990. This drastic rise in surface temperature is shown to occur in association with a large increase in potential evaporation. The southern African region is simultaneously projected to become generally drier in response to enhanced anthropogenic forcing, with only slight rainfall increases projected to occur over parts of the central and eastern interior of South Africa. That is, the water balance over the region is projected to become increasingly negative under conditions of enhanced anthropogenic forcing. Seed germination behavior, micropropagation and Agrobacterium-mediated transformation of Salvia runcinata (L.f.): implications for conservation and cultivation S. Figlan a, J.M. Kossmann a, N.P. Makunga a,b a Institute for Plant Biotechnology, Department of Genetics, Faculty of Natural Sciences, Stellenbosch University, Private Bag X1, Matieland, South Africa b Department of Botany and Zoology, Faculty of Natural Sciences, Stellenbosch University, Private Bag X1, Matieland, South Africa The seed germination behavior, optimal conditions for micropropagation and transformation efficiency of S. runcinata were determined. S. runcinata is particularly rich in rosmarinic acid and has also been identified as an alternative source of natural α-bisabolol; a compound which is an important component of cosmetic products, making it highly valued in the cosmetic industry. Nevertheless medicinal plants of the mint family are under pressure owing from overexploitation from their natural environment. The methods of extraction employed are almost invariably crude and unsystematic. As a result, the roles of exploitation may exceed those of local natural regeneration. There is thus an urgent need to develop and implement regeneration/ conservation strategies for this sage species. In this study, the common means of regeneration and propagation of S. runcinata included in vitro seed germination and micropropagation methods. The efficacy of smoke and scarification treatments for germination improvement was tested. Hairy roots were also established using three different strains of Agrobacterium rhizogenes (A4T, LBA9402 and C58C1) as an attempt to enhance secondary metabolite production of the plant. The most effective germination treatment proved to be a 3 min exposure of seeds to 25% H2SO4 combined with a concentration of 10 − 5 M smoke solution resulting to more than 80% germination. Shoot proliferation was significantly higher using nodal explants with addition of 4.43 μM BA generally promoting the average number of shoots per nodal explant. The LBA9402 strain was more efficient in the establishment of putative hairy root lines. However, only two hairy root clones survived subculturing and polymerase chain reaction with primers for the genes rolA, rolB, rolC and ags confirmed the integration of T-DNA fragment from the Ri plasmid of A. rhizogenes to the genome of these clones obtained after transformation by A4T strain. Southern blot analysis also confirmed the presence of rolA gene in the two A4T clones. Elucidation of defense responses associated with inducer application in Pinus patula K. Fitza a, A.A. Myburg a, E.T. Steenkamp b, K. Payn c, S. Naidoo a a Department of Genetics, Forestry and Agricultural Biotechnology Institute (FABI), University of Pretoria, Pretoria 0002, South Africa b Department of Microbiology and Plant Pathology, FABI, University of Pretoria, Pretoria 0002, South Africa c Mondi South Africa, P.O. Box 12, Hilton 3245, South Africa A major challenge for the pine species in South Africa is the necrotrophic fungus Fusarium circinatum, which causes the disease pitch canker. Commercial forestry incurs large economic losses from the pathogen F. circinatum, mostly occurring due to post planting stress, where 20–30% of the planting stock of P. patula is lost due to infection annually. One means of enhancing defense is through applying chemicals or biologically derived treatments known to activate induced resistance, throughout the entire plant. Induced resistance may involve chemical defenses, e.g. production of terpenoids, phenolic metabolites, protein defenses such as pathogenesis related proteins and anatomical defenses such as cell wall lignification. A panel of 10 different inducers were chosen to determine their efficiency in activating induced resistance in P. patula. The application of chitosan at a concentration of 10 mg/ml resulted in significant reduction in lesion length over a 6 week period after challenge with F. circinatum. Subsequent characterization of the molecular basis of induced resistance was achieved by analyzing the expression profiles of selected putative defense genes. These P. patula putative orthologs were identified based on Expressed Sequence Tag (EST) sequences available from Pinus taeda using a phylogenetic approach. Reverse transcription-quantitative PCR assays revealed that phenylalanine ammonia lyase (PAL) showed a fourfold up-regulation in P. patula seedlings treated with chitosan SAAB Conference Abstracts compared to un-treated plants, suggesting the onset of induced resistance. Chitosan application may hold promise in inducing resistance in P. patula against F. circinatum and could form part of an integrated management strategy to control the disease. Comparative wood anatomy of six genera of the family Bignoniaceae in Nigeria A.E. Folorunso, O.S. Awosika Botany Department, Obafemi Awolowo University, Ile-Ife, Nigeria Comparative wood anatomy of six genera of Bignoniaceae in Nigeria were carried out to assess the taxonomic and diagnostic characters from the wood samples of the selected genera, identify the primitive characters and the species possessing them, investigate the phylogenetic relationship among members of the family and use the wood characters in producing a key for easy identification of the species of Bignoniaceae. Wood specimens were collected from different latitudes and ecological zones such as the wet forest, dry forest and derived savanna areas of Nigeria and assigned accession numbers. Small pieces of the species were macerated in Schutz's fluid; a mixture of equal 10% solution of Chromium trioxide and 10% solution of concentrated nitric acid, stained in 1% Safranin O and mounted on a slide using dilute glycerol as a mountant. The dimension and anatomical characteristics of the vessel elements and fibers were described respectively. The length and diameters of twenty vessel elements and fibers were measured from the macerated materials; fiber-length and vessel-length ratio (F/V ratio) was also calculated. Small block of about 1 cm × 1 cm × 1 cm were removed from the wood samples; transverse, tangential and radial longitudinal sections were made on Reichert Sledge Microtome at varying thickness between 8 and 15 μm. The sections were stained in 1% solution of Safranin O for 15 min, washed in three changes of water, counter-stained in 1% alcian blue for 3–5 min, dehydrated through series of ethylalcohol: 30, 50, 70, 90 and 95%, cleared in xylene and mounted in DPX mountant. Photomicrographs of the wood sections were taken with Leitz camera mounted on Dialux research microscope. The wood is diffuse porous and shows the presence of growth ring in all the six genera. Diagnostic wood characters are mainly confined to perforation plates, vessel length, fiber types, ray types and number of adjoining vessel members. Major primitive characters shown include presence of more tracheids, elongated and narrow vessel elements, highly oblique end wall, vessel angular in shape and more solitary vessels in transverse section distribution. Phylogenetically, Tecoma stans and Crescentia cujete are the highly primitive members, Stereospermum acuminatissimum and Markhamia tomentosa are highly advanced species while the position of Newbouldia laevis and Spathodea campanulata is intermediate. 185 An analysis of landscape connectivity of the Grassland Biome of Mpumalanga using graph theory L. Fourie a , M. Rouget a, M.C. Lötter b a Department of Plant Science, University of Pretoria, Pretoria 0002, South Africa b Mpumalanga Tourism and Parks Agency, Private Bag X1088, Lydenburg 1120, South Africa The South African Grassland biome is one of the most threatened biomes in South Africa. According to National Land Cover data, 45% of the Grassland biome area is transformed, degraded or severely invaded by alien plants and the remaining natural areas are highly fragmented. The connectivity between habitat patches is very important for populations to survive in this fragmented landscape and the analysis and quantification of this connectivity can be used for reserve design and to direct conservation efforts. The aim of this study is to analyze connectivity in the grassland biome of Mpumalanga using graph theory. Graph theory-based connectivity indices have the ability to combine spatially explicit habitat data with species specific dispersal data and can quantify structural and functional connectivity over large landscapes. Natural areas were identified using 2008 land cover data for Mpumalanga. This study shows the level of connectivity of the Grassland Biome of Mpumalanga for different grassland species with dispersal distances ranging from small to large. The habitat patches most important for maintaining connectivity in this area are identified. Additionally, the importance of protected areas as well as the importance of abandoned croplands for maintaining overall connectivity is demonstrated. These results can be used to inform management decisions and reserve design in this biome. Employing biotechnology and cryobiological research to conserve threatened plant species M.M. From, M. Landry Laboratory for Endangered Plants, Centre for Conservation & Research, Omaha's Henry Doorly Zoo, Omaha, Nebraska 68107, USA Plant biotechnology developed in the 21st century can serve as a means to forestall the final extinction of many plant species. The vast majority of plant species on earth today have not yet been researched for their possible benefits to mankind and all other life forms. Omaha's Henry Doorly Zoo established an ex situ plant laboratory to research plant species from threatened habitats and reintroduce propagules of those species in their original habitats. Sustainable populations are thus created by increasing the total number of specimens at a given site. As an example, 0ver 840 endangered native orchid species, representing 5 genera: Aeranthes spp., Aerangis, spp., Bulbophyllum spp., Calanthe sp., and Cryptopus sp. (13 species) have been reintroduced into Madagascar in collaboration with Malagasy 186 SAAB Conference Abstracts scientists from CITES and graduate students who have received biotechnology training in the zoo's laboratory. The head of the Madagascar forestry department and local residents were collaborators for plant reintroductions made in the rainforest. Seedling survival, based on the number of plants displaying active shoot and root growth five years after reintroduction, ranged an average of 76%. Samples of seed and spore accessions from threatened plant species are also preserved in the zoo's frozen seed bank. Currently, seeds and spores from more than 150 species are in the cryobank, some preserved using novel techniques developed in the zoo's laboratory, creating a backstop to extinction by saving germplasm for future research projects and long term conservation plans that can eventually lead to species recovery on a broader scale. Plant invasions, resilience, economics, and restoration: Can fynbos pay for alien management? M. Gaertner a, H. Nottebrock b, H. Fourie c, S.D.J. Privett d, D.M. Richardson a a Centre for Invasion Biology, Department of Botany and Zoology, Stellenbosch University, Private Bag X1, Matieland 7602, South Africa b Potsdam University, Plant Ecology and Conservation Biology, Maulbeerallee 2, 14469 Potsdam, Germany c Western Cape Department of Agriculture, Private Bag X1, Elsenburg 7607, South Africa d Fynbos Ecoscapes, Witkrans, Gansbaai 7220, South Africa We explored the influence of different invasive plant species on the resilience of three different invaded sites in the Cape Floristic Region by testing a variety of management strategies through field trials and experimental manipulations. To investigate the financial feasibility of introducing native species which can be used for sustainable flower harvesting as an incentive for restoration we linked ecosystem services to the beneficiaries of ecosystem restoration conducting a cost–benefit analysis. Our results show that the ecosystem was sufficiently resilient to allow autogenic recovery to occur following removal of the invasive species. Native cover, species richness, diversity or evenness increased significantly after restoration at all three sites, whereas alien cover decreased significantly. Soil restoration treatments resulted in a decrease of available nitrogen, but this had no effect on plant cover (alien or native), species richness, diversity or evenness. We therefore argue that in this case soil restoration treatments were futile and added unjustifiable expense to the restoration program. We learned that an adaptive approach involving revising management objectives throughout the management process would have been more appropriate. The financial analysis shows that the density of invasion is the key determinant influencing whether clearing of invasive plants and restoration results in a net gain or loss when land is restored to a state conducive to sustainable harvesting. Functional evaluation of a drought-induced “late embryogenesis abundant” protein gene from cowpea I. Gazendam a , D. Oelofse a , D.K. Berger b a Agricultural Research Council-Roodeplaat Vegetable and Ornamental Plant Institute, Private Bag X293, Pretoria 0001, South Africa b Department of Plant Science, Forestry and Agricultural Biotechnology Institute (FABI), University of Pretoria, Pretoria 0002, South Africa Drought tolerance of plants is governed by multiple genes. Biotechnology can be applied to improve a crop's drought tolerance through candidate gene identification, followed by transformation or molecular breeding strategies. Cowpea (Vigna unguiculata (L.) Walp) was used as a source of candidate drought responsive genes, since it is a highly drought tolerant legume crop. A cDNA library, enriched for drought responsive cowpea genes, was generated following suppression subtractive hybridization of two cultivars differing in their drought tolerance. DNA microarrays were employed to identify genes responding to drought stress. A gene encoding an atypical group 5 late embryogenesis abundant protein (LEA5) was selected for further characterization. It was shown to be highly upregulated by drought, application of the plant stress hormone abscisic acid and other abiotic stress conditions (salt and cold) in cowpea leaves. LEA proteins play an important protective role during drought and other abiotic stresses of plants, but group 5 proteins are not as well studied as the classical LEA groups. This gene was therefore over-expressed in the model plant Arabidopsis thaliana to study its role in tolerance to drought. Seedling stress tests were performed in vitro in the presence of osmotic agents (high molecular weight polyethylene glycol) that simulate drought conditions in the soil. Quantitative growth parameters (hypocotyl and primary root elongation) of homozygous transgenic T4 seedlings were measured and compared to non-transgenic controls. No statistically significant improvement in growth and recovery after stress could be attributed to the cowpea LEA5. This LEA protein could, therefore, not improve the drought tolerance of transgenic A. thaliana lines. Its possible role in cold stress protection is suggested as a follow-up study. Banksia ericifolia invading South Africa as predicted – A major threat or just symptom of a peculiar fire regime? S. Geerts a,b, J.R. Wilson a,b, D.M. Richardson a, M. McGeoch a, M. Gaertner a, J.J. Le Roux a, S. Kritzinger-Klopper a, C. Muofhe a a Department of Botany and Zoology, Centre for Invasion Biology, Stellenbosch University, Private Bag X1, Matieland 7602, South Africa b South African National Biodiversity Institute, Kirstenbosch National Botanical Gardens, Claremont, South Africa SAAB Conference Abstracts In the Cape Floristic Region (CFR) of South Africa there is a long history of alien invasive Australian plant species. Some of these species, for example those in the genus Hakea (Proteaceae family), are well adapted and thrive under Fynbos fire regimes and have become widespread invaders. However, many potentially invasive species are only small infestations and assessing and controlling these at an early stage is the most cost effective. Recently, another Australian Proteaceae genus, Banksia, was listed as invasive in South Africa. With similar life history traits than Hakeas (serotinous, with large canopystored seed banks dispersed by wind in the post fire invasion window) Banksias, and in particular B. ericifolia have been predicted to be high risk introductions in fynbos. We assess the status of all known B. ericifolia populations in the CFR. At the only site where B. ericifolia has become invasive, we determine the cause of its spread. The invasive population arose from an ornamental farm hedge planted 30 years ago with sporadic recruitment into the surrounding natural vegetation. It now covers an area of about 150 ha with approximately 10 000 individuals. The population was mapped and levels of recruitment and plant size were determined. From these data, size distribution and time to first flowering and post fire seed dispersal distances were calculated. The ability to attract local pollinators in this preferential outcrossing species is discussed. We present preliminary analyses linking a particular humaninduced fire regime in the immediate area of the invasion to the observed episodic recruitment. We contrast this to other sites where B. ericifolia has been grown under different fire regimes, and discuss our results in the light of risk analysis of the species. Lastly we assess the effectiveness of clearing operations on B. ericifolia. Phylogenetic relationships within subtribe Terminaliinae (Combretaceae) J. Gere a,b, O. Maurin a,b, M. Van der Bank a,b a African Center for DNA Barcoding, University of Johannesburg, Department of Botany and Biotechnology, P.O. Box 524, Auckland Park 2006, South Africa b Department of Botany and Plant Biotechnology, University of Johannesburg, P.O. Box 524, Auckland Park 2006, Johannesburg, South Africa Subtribe Terminaliinae is a taxonomically and phylogenetic complex group within Combretaceae. Previous morphological studies on the family recognized five genera, Terminalia, Buchenavia, Conocarpus, Pteleopsis and Anogeissus with Bucida transferred to Terminalia. Recent molecular studies indicated that the largest genus, Terminalia (approximately 200 species) is polyphyletic with the proposal that all genera, except for Conocarpus, should be transferred to Terminalia. In the current study an extra plastid gene, ndhF, as well as an increased number of taxa, was added to the existing data set (ITS, rbcL and spacers trnH-psbA and psaA-ycf3). Within Terminaliinae three major clades are retrieved: clade I comprises mainly 187 Asian Terminalia and Anogeissus species; clade II includes Buchenavia, Bucida, Pteleopsis and American Terminalia species, and clade III comprises mainly African Terminalia with a few Asian and Australian Terminalia species embedded in it. Conocarpus is supported as sister to the rest of the subtribe. Plant diversity of a lowland dipterocarp rainforest in Samar Island, Philippines W.S.M. Gruezo Professor 12, Plant Biology Division, Institute of Biological Sciences, College of Arts and Sciences, University of the Philippines Los Banos, College 4031, Laguna, Philippines The plant diversity of a lowland dipterocarp rainforest in Samar Island, Philippines (i.e. Borongan, Eastern Samar Province) is composed of 485 species in 276 genera and 99 families. Of the 485 species, 9 species are epiphytes, 24 ferns, 17 grasses, 83 herbs, 43 lianas, 15 vines, 17 shrubs, 91 small trees, 120 medium-sized trees, 53 large trees and 29 tree-like plants. In terms of economic or functional importance, these 485 species serve the following uses: 207 landscape plants, 117 timber sources, 58 ornamentals, 42 for cottage industry, 33 weeds, 25 medicinals, 17 fruit crops, 9 each as fiber and poison sources, 6 pasture and forages, 3 spices, 2 each with edible fruits, for masticatory purposes, ecological functions and soil erosion control, 1 each for beverage, dye source, perfume and animal food. In addition to a number of new species records for Samar Island, one important taxonomic and biogeographic discovery was made, particularly in the vicinity of Mt. Apoy. This involves the discovery of Falcatifolium gruezoi de Laubenfels, (Podocarpaceae) known locally as karis-karis (Waray), binaton (Tagalog) and Gruèzo sickle-leaf (in English). Its discovery represents a new genus record for Samar Island and also made possible the description of a new forest formation type termed as mixed Falcatifolium forest, which can only be found in a specific habitat type, here described also as new under the name “pseudo-peat swamp”. The discovery of another species of conifer, Podocarpus neriifolius D. Don [malaadelfa (Tagalog), Podocarpaceae] brings the total number of conifer species in Samar Island to five, thus this particular species is a new species record for the island. In terms of plant endemicity, the study area which is a part of the Suribao Watershed has 256 endemic species representing 53% of the total species record for this particular watershed, which largely belongs to a lowland dipterocarp rainforest type. This watershed has a very high plant diversity i.e. its calculated Shannon–Weiner diversity index (H′) is 4.56 (based on measurements of 25 circular sample plots, each with an area of 1/8 ha). Towards an understanding of indigenous Afromontane forest regeneration and expansion in Buffelskloof Private Nature Reserve, Mpumalanga W.A. Haddad a, M. Rouget a, A.E. Van Wyk a, J.E. Burrows b 188 SAAB Conference Abstracts a Department of Plant Science, University of Pretoria, Pretoria 0002, South Africa b Buffelskloof Herbarium, P.O. Box 710, Lydenburg 1120, South Africa Several recent studies show a marked increase of woody vegetation in many different biomes across the globe. The aim of this honors project was to understand forest regeneration under different land uses and to quantify the spatial extent of indigenous Afromontane forest over time in the Buffelskloof Private Nature Reserve, Mpumalanga, South Africa. A time series of aerial photographs from 1956, 1981 and 2004 was constructed in a GIS and used to locate and quantify the areas converted from grassland and pine plantations to indigenous woody communities. A marked increase in woody cover was found in some areas, while the forest/ grassland interface remained stable in other areas. A total of four 10 m × 10 m plots were investigated, two located in former grassland and two in areas that were under pine plantations up to twenty years ago. Further, two 100 m transects were recorded through an area of former grassland and an area of former plantation. None of these areas have been burnt in the past two decades. Investigation was made into the reproductive and dispersive biology of some of the most commonly encountered species in an effort to see whether this has an effect on which woody species colonizes an area first. From the results it seems that there is not a major difference between the species and structural compositions of plots located on areas with different vegetation histories (grassland vs. plantation), but that other factors such as distance to established forest (seed source), soil moisture and aspect has a greater influence. This study and further work along these lines can be of great value in the rehabilitation of old commercial plantations to indigenous Afromontane forests along the Escarpment. Root endophytes from Persea americana and their role against Phytophthora cinnamomi infection J.D. Hakizimana a,b, M. Gryzenhout e, T.A. Coutinho a,d, N. Van den Berg a,c a Forestry and Agricultural Biotechnology Institute (FABI), University of Pretoria, Pretoria 0002, South Africa b Department of Plant Science, University of Pretoria, Pretoria 0002, South Africa c Genetics, University of Pretoria, Pretoria 0002, South Africa d Microbiology and Plant Pathology, University of Pretoria, Pretoria 0002, South Africa e Department of Plant Sciences, University of the Free State, South Africa Endophytes are microorganisms that, during a viable period of their life, symptomlessly colonize the living internal tissues of plants. Root endophytes have been investigated in plants and used as biocontrol agents against plant pathogens. However, little is known about the diversity of endophytes in P. americana (avocado) roots and their potential role in biocontrol of P. cinnamomi (Pc). This Oomycete is the causal agent of Phytophthora root rot, the most important disease in avocado producing countries worldwide. The aim of this study was to identify bacterial and fungal endophytes from avocado roots and to use selected endophytes with potential biological activity against P. cinnamomi in planta. The identification was based on morphological characteristics of the isolates as well as using ITS, β-tubulin, EF-1α and 16S ribosomal RNA gene sequencing. Twenty four different fungal species and 8 bacterial species were identified as endophytes from the avocado roots from various locations in South Africa. Two bacterial strains and 2 fungal strains were selected on their antagonistic effects against P. cinnamomi. Clonal as well as endophyte-free tissue-cultured avocado plants were inoculated with each of the selected endophytes at 10 8 CFU ml - 1 for bacteria and 10 6 spores ml - 1 for fungi. Four weeks after endophyte inoculation, each plant received 10 5 Pc zoospores ml - 1 directly sprayed onto roots, except for negative control plants. Positive control plants received no endophytes. Phytophthora symptoms were assessed 21 days post infection and disease incidence was calculated. Avocado plants that received endophytes prior to Pc-infection showed a significant decrease in disease incidence with ratings from 2-40% compared to 94-100% for the positive control plants that received no endophytes. Endophytes and their association with Dichapetalaceae C.B.S. Hendriks a, J.J.M. Meyer a, C.F. Van der Merwe b a Department of Plant Science, University of Pretoria, Pretoria 0002, South Africa b Laboratory for Microscopy and Microanalysis, University of Pretoria, Pretoria 0002, South Africa Dichapetalum cymosum (Poison leaf) is a very common problem plant in southern Africa. Fluoroacetic acid, is believed to be the poisonous entity in the plant, might be produced by the plant, but the micro-organisms associated with this plant may also play a role in the production thereof. By isolating the bacteria the capabilities of the isolated endophytes to synthesize fluorinated compounds were studied. It is suggested from preliminary results that symbionts might play a role in the synthesis of the poisonous entities in the Dichapetalaceae family, but further investigation is required. The detection of glandular lesions on the abaxial side of the leaf led to closer examination and the cross sections revealed unusually deformed epidermis cells with adjacent cells containing vacuoles filled with phenolic-like crystals. Transmission electron microscopy (TEM) of the spongy parenchyma cells directly above the glandular lesions indicated the presence of clusters of small, viruslike particles (VLPs) in the chloroplasts. Observations by TEM show that these VLPs have unusual lattice formation, differing from the typical viral-capsid protein arrays and, hence, the question is posed whether this might be of virus origin. Tapura fischeri (Leafberry tree) is a tree member of the same family, and it was found to contain a fluorinated compound. Endophytes were also found in the plant and similar glandular SAAB Conference Abstracts lesions with analogous VLPs were observed at these sites. This might implicate that endophytes have a share in the biosynthesis of the fluorinated compounds found in Dichapetalaceae. Numerous factors ought to be considered to establish the chemical ecology of the intricate system regarding the endophytes and the toxicity of the family Dichapetalaceae. The taxonomic significance of the cypsela morphology in the genus Nolletia Cass. (Asteraceae) in southern Africa P.P.J. Herman National Herbarium, South African National Biodiversity Institute, Private Bag X101, Pretoria 0001, South Africa 189 model (University of Basel), it was established that six species had significant anti-HIV activity ranging between 12 and 21 μg/ml (IC50). Subsequent toxicity tests also revealed little or no toxicity for these extracts. With the use of NMR-based metabolomic analysis the search for active constituents was conducted and areas of interest were identified. Regions 2.55 ppm3.16 ppm, 6.20 ppm-6.40 ppm, 5.72 ppm-6.28 ppm, 6.60 ppm7.00 ppm, 7.24 ppm-8.04 ppm and 8.24 ppm-8.98 ppm were identified as being the main contributors to bioactivity. The isolation of active constituents will be guided by focusing on compounds having chemical shifts in these regions to identify possible lead compounds for further studies. The role of pollinators in the assembly of Erica communities The genus Nolletia Cass. belongs to the tribe Astereae of the family Asteraceae. Currently eight species are recognized in southern Africa. The genus has never been revised and there is no key available dealing with all of the species. Full descriptions of the species are also scanty or non-existing in the available taxonomic literature. A species was identified as being toxic to cattle and another species from the Pretoria area was recognized as a new species. A taxonomic revision of the genus is currently under way. Based on the cypsela morphology, the genus can be divided into two groups. One group has plain, flat epidermal cells and longish twin hairs. The other group has globose epidermal cells each with very small twin hairs covering the entire surface of the cypsela. In this group a taxon with a slight variation was observed: it has globose epidermal cells arranged in pairs, each with one twin hair between them. The paired globose cells are scattered over the cypsela surface. Determination of anti-HIV active constituents of Helichrysum species by means of metabolomics H.M. Heyman a, V. Maharaj b, C. Kenyon b, J.J.M. Meyer a a Department of Plant Science, University of Pretoria, Pretoria 0002, South Africa b Biosciences, CSIR, P.O. Box 395, Pretoria 0001, South Africa Being the home to more than 35% of the world Helichrysum species (c.a. 244 species) of which many are used as traditional medicine it is only fitting that research into these species should be conducted in South Africa. The most commonly used Helichrysum species for their medicinal properties are Helichrysum cymosum, Helichrysum odoratissimum, Helichrysum petiolare and Helichrysum nudifolium. The medicinal uses include the treatment of coughs, colds, fever, infection, headaches, menstrual pain and they are very popular for wound dressing. In previous studies conducted on 12 Helichrysum species, it was clear that some species have significant anti-HIV activity (5-12 μg/ml). In this current study another 35 randomly selected Helichrysum species were collected and tested for anti-HIV properties. Using an in-house Deciphr method on a full virus A. Heystek, A. Pauw Department of Botany and Zoology, Stellenbosch University, Private Bag X1, Matieland 7602, South Africa Plant-pollinator interactions are proposed to be one of the main factors responsible for the diversification and maintenance of the exceptional plant species richness of the Cape Floristic Region. We investigated the role that pollinators play in the assembly of Erica communities since 426 members of this genus are crammed into a small area in the south-western Cape and they display a range of pollination syndromes (80% entomophilous, 15% ornithophilous, 5% anemophilous). Vegetation plot data from ten regions in the fynbos biome was used to test whether the frequency of co-occurrence of species with the same pollination syndrome differs from a null model of random community assembly. We found that Erica communities were assembled randomly with respect to pollination syndrome in six regions, but were significantly overdispersed in four regions. Overdispersion is consistent with competition for pollinators between co-flowering species. To better understand these ecological processes, we conducted field experiments with six Erica species that are all primarily pollinated by the Orange-breasted Sunbird Anthobaphes violacea. We transplanted inflorescences of a focal Erica species into communities containing another ornithophilous Erica species and recorded pollination rates in the transplanted and resident species in relation to the floral density of the resident species. In five cases pollination rate in the transplanted species was not related to the floral density of the resident species. However, there was one case of inter- and intraspecific competition for pollinators and one case of intraspecific pollination facilitation. Our investigation of patterns and processes of Erica community assembly concur that pollination can structure communities in non-random ways with potential for both facilitation and competition. The role of resource limitation in the occurrence and persistence of rewardless pollination systems in Disa (Orchidaceae) N. Hobbhahn a,b, B. Bytebier, S.D. Johnson a, L.D. Harder b 190 SAAB Conference Abstracts a School of Life Sciences, University of KwaZulu-Natal, Private Bag X01, Scottsville 3209, South Africa b Department of Biological Sciences, University of Calgary, 2500 University Drive NW, Calgary, Alberta T2N0N5, Canada Pollination by deceit, whereby flowers do not offer any rewards to their pollinators, is frequently explained as a means of avoiding the resource costs of reward production, especially when resources are limited. To mitigate fitness losses due to reduced attractiveness, rewardless species may allocate more resources to other floral functions that promote reproduction, such as display size, floral longevity, or gamete production. Given the lack of estimates of the resource costs of reward production in lineages with deceitful species, the role of resource limitation in the occurrence and persistence of rewardlessness remains unclear. We assessed this resource-limitation hypothesis of rewardlessness with a phylogenetically controlled comparison of the energy costs of flower production and maintenance, and nectar production in the African orchid genus Disa, in which nectar production has evolved at least seven times from rewardless ancestors. The costs of 24-h nectar sugar production and maintenance are minute compared to those of flower production, but can accrue considerably due to floral longevity. However, pollination-induced wilting following earlier and more frequent pollinations of rewarding than of rewardless flowers limits cost accrual in a higher proportion of rewarding than rewardless flowers. We detected no trade-offs between nectar production and other floral traits in rewarding species, which invested more energy overall than rewardless species in reproduction. Overall greater resource investment in reproduction in rewarding than in rewardless species suggests that the resource costs of reward production may not be limited to the costs of the actual rewards. Instead, reward production may be associated with a life history that trades off present reproduction against long-term survival, whereas rewardless plants may live longer due to lower reproductive investment per season. Transitions from rewardlessness to reward production may be hampered by lower efficiency of resource acquisition in rewardless than in rewarding species. Iris pseudacorus L. (yellow flag) has escaped cultivation in South Africa T.P. Jaca Early Detection and Rapid Response Programme, South African National Biodiversity Institute, Private Bag X101, Pretoria 0001, South Africa The majority of plants that have been introduced to South Africa perform the purpose for which they are intended and therefore benefit humans in multiple ways. A small portion of introduced plants, however, escape from cultivation. While most introduced plants will not establish populations outside of cultivation, some probably will become invasive. I. pseudacorus native to Eurasia was introduced sparingly to South Africa as an ornamental plant. The aim of the study was to examine if I. pseudacorus has escaped cultivation or if it is still contained under cultivation. Surveys were conducted in three provinces of South Africa, Gauteng, Limpopo and KwaZulu-Natal. The results indicated that I. pseudacorus has escaped from cultivation to wetlands, rivers and other moist habitats, where it makes brilliant yellow displays during spring to early summer. In most of the areas surveyed, the first plants probably have arisen from rhizomes discarded or else removed from nearby gardens and nurseries. Subsequent spread has resulted from the breaking up of rhizomes or from seeds, which are produced in abundance. In some places his species has stated to spread to such an extent and forms such a scattered pattern that it has the appearance of a native plant. Invasiveness of Opuntia salmiana – Experimental study on its vegetative and sexual propagation T.P. Jaca a, H.M. Venter b a Early Detection and Rapid Response Programme, South African National Biodiversity Institute, Private Bag X101, Pretoria 0001, South Africa b Plant Propagation and Rehabilitation Technologies cc, P.O. Box 99273, Garsfontein East 0060, Pretoria, South Africa O. salmiana (bur cactus) resembles the well known jointed cactus (Opuntia aurantiaca) is less spiny with long round cladodes that do not detach that easily. It is native to Chaco of northern Argentina, South-Eastern Bolivia and Paraguay and was probably introduced to South Africa as an ornamental. Plants are shrub like, ± 1 m high, often sprawling with long cylindrical stems 1-2 cm in diameter. During summer the plants are recognized by small bright red club-shaped fruits which bear several small 1-2 cm long joints on their tips. Several species of the genus Opuntia e.g. Opuntia imbricata, Opuntia kleiniae, Opuntia phaeacantha and Opuntia rufida, have fruits that proliferate joints which develop into new plants. These joints are clonal propagules also known as bulbils and are easily detached by passing animals. They are armed with many small bristle-like barbed spines which attach easily to fur, clothes or skin for potential long distance dispersal. Production of attractive red fleshy fruits increases the chances of the bulbils being spread by frugivores. Plant material collected at Wagpos in the Brits district of North West province was studied to determine if the species propagates both through sexual and vegetative regeneration. A stereo microscope study showed that possible viable seeds are produced within the fruits. Vegetative and seed propagation trials were studied in controlled environments. The regeneration ability of bulbils, cladodes stems, timing of shoot emergence and root emergence were studied. Seeds were sown in two treatments: in filter paper in petridishes treated with distilled water and sand in the laboratory. Bulbils and cladodes regenerated well and seeds did not germinate at all in both treatments. It is concluded that bulbils and cladodes are more crucial than seeds for the spread of SAAB Conference Abstracts O. salmiana, contributing to an aggressive increase in population size and the importance of frugivores. Proteomic analysis of wheat treated with a novel plant activator R. Janse Van Rensburg a, G. Kemp b, J.C. Pretorius c, B. Visser a a Department Plant Sciences, University of the Free State, P.O. Box 339, Bloemfontein 9300, South Africa b Department Microbial, Biochemical and Food Biotechnology, University of the Free State, P.O. Box 339, Bloemfontein 9300, South Africa c Department Soil- and Crop- and Climate Sciences, University of the Free State, P.O. Box 339, Bloemfontein 9300, South Africa Plant activators present a new and exciting approach to improve crop production by increasing overall plant health and yield. The aim of this study was to determine the effect of a novel plant activator called SS on wheat (T. aestivum) after foliar treatment using shot-gun proteomics. Total protein extracted from SS treated wheat was separated on SDSPAGE. Polypeptides present in different sections of each gel lane was digested with Trypsin and subjected to LC-MS/MS analysis. Expression levels of identified polypeptides were calculated using spectral counting. A total of 365 polypeptides were identified with 95 showing increased levels following SS treatment. Preliminary results indicated that SS application improved the plant's photosynthetic ability with three different aspects being affected. The proteomic results for selected polypeptide encoding genes were confirmed using qPCR analysis. The positive influence of SS application on photosynthesis in wheat was confirmed using chlorophyll fluorescence data. First report of Coniothyrium stem canker of eucalypts in Zimbabwe 191 four sites on E. grandis, Eucalyptus camaldulensis, E. grandisx-camaldulensis hybrid clone and Eucalyptus propingua. The ITS region, exons 3 through 6 of the β-tubulin gene and the intron of the translation elongation factor 1-α gene were sequenced to identify the causal pathogen. Representative isolates from Zimbabwe were compared with authenticated isolates of Teratospheria zuluensis and Teratospheria gauchensis. Sequence comparisons identified the pathogens as T. gauchensis. This study is the first to confirm the presence of Coniothyrium stem canker on eucalypts in Zimbabwe. Furthermore, it is the first to report T. gauchensis in Southern Africa. Using model and manipulated flowers to study pollinatormediated selection S.D. Johnson School of Life Sciences, University of KwaZulu-Natal Pietermaritzburg, Private Bag X01, Scottsville 3209, South Africa Strong selection in the wild has the effect over time of reducing phenotypic variation. To understand the historical influence of selection, it is therefore often necessary to reintroduce phenotypic variation into populations. This can be done expensively through genetic engineering or much less expensively through the use of natural hybridization, reciprocal translocations, physical manipulation of the phenotype or even construction of model flowers. We have used simple morphological manipulations and reciprocal translocations to detect the potential for selection to act on flower color, nectar guides, shape, scent, protandry, and plant height, and used model flowers to detect the potential for selection to act on flower color, shape and scent. Measurement of the male component of fitness remains a challenge and we have refined the Peakall method of pollinia staining so that we can now track the fate of individual pollen massulae and thereby estimate male pollination success in orchids with greater precision. L. Jimu a,c, S. Chen b, M.J. Wingfield b, E. Mwenje c, J. Roux b a Forestry Department, Forestry and Agricultural Biotechnology Institute (FABI), University of Pretoria, Private Bag X20, Hatfield, Pretoria 0028, South Africa b Department of Microbiology and Plant Pathology, Forestry and Agricultural Biotechnology Institute (FABI), University of Pretoria, Private Bag X20, Hatfield, Pretoria 0028, South Africa c Bindura University of Science Education (BUSE), Private Bag 1020, Bindura, Zimbabwe J.M. Kalwij a,c, M.P. Robertson b, B.J. Van Rensburg b,c a Institute of Ecology and Earth Sciences, University of Tartu, Tartu 51005, Estonia b Department of Zoology and Entomology, University of Pretoria, Pretoria 0002, South Africa c DST-NRF Centre for Invasion Biology, Stellenbosch University, Private Bag X1, Matieland 7602, South Africa Coniothyrium stem canker, caused by species of Raederiella (previously Coniothyrium zuluense) is one of the most important eucalypt stem diseases in the southern hemisphere. During a disease survey conducted in Zimbabwe, symptoms of the disease, characterized by discrete dark brown sunken lesions, kino exudation and pockets in the wood, were observed in Invasive alien plants pose a major threat to biodiversity in general and to that of montane ecosystems in particular. The elevational gradient of montane ecosystems offers ample opportunities to study the colonization rate of alien plant species. Yet to date few such studies exist mostly due to limitations in research funding and scarcity of long-term monitoring Rapid colonization by annual alien plants of a high montane roadside in the Drakensberg, South Africa 192 SAAB Conference Abstracts programs. This study aimed at filling that gap by annually recording the upper altitudinal limits of alien plant species in the Drakensberg mountain range. From 2008 to 2011 we sampled a 20-km long stretch of the Sani Pass road covering an elevational gradient of 1500-2874 m above sea level. The average alien species richness did not change over time, with 29.5 annual and 42.0 perennial species. With each subsequent observation we recorded ~7 new alien species to the study area. However, only 19 annuals and 31 perennials were observed annually. A repeated-measures ANOVA showed a significant change in the upper altitudinal limits of annuals that was equivalent to an ascend of ~70 m per year (ANOVA, F = 5.502, dfyear(adj) = 2.340, dferror = 54, P = 0.005), but not so for the perennials. This rapid ascend could not be attributed to changes in local climatic conditions, density of vehicle movements, or minimum residence time of these alien species in South Africa. Nearly all of our observations were spatially clustered around potential introduction sources such as the South African border post or residential dwellings. Therefore, the large number of new and disappearing species in combination with rapidly ascending upper altitudinal limits around potential introduction sources suggests that propagule pressure is high and that the process of colonization and distribution is still ongoing. These results also suggest that an observation period of five years is already sufficient to detect trends in alien plant species. Quality control of commercially important essential oils and biological activities of selected oils from South African flora G.P.P. Kamatou a , M. Sandasi a, S.F. Van Vuuren b, R.L. Van Zyl b, A.M. Viljoen a a Department of Pharmaceutical Sciences, Faculty of Science, Tshwane University of Technology, Pretoria, South Africa b Department of Pharmacy and Pharmacology, Faculty of Health Sciences, University of the Witwatersrand, Parktown, South Africa Essential oils are volatile compounds isolated from aromatic plants. Like any other product intended for commercial purpose, essential oils sold on the market should meet prescribe standards for safety and efficacy in order to give the desired effect to consumers. The quality control of five essential oils including frankincense (B. rivae), buchu (Agathosma betulina), cape chamomile (Eriocephalus tenuifolius), geranium (Pelargoniun graveolens) and tea tree (Melaleuca alternifolia), will be discussed with regard to the major constituents used to determine “good oil”. The oil is usually evaluated based on the relative percentage calculated from the FID detector. Limitations of the use of relative percentage area, rather than quantification based on calibration curves, will be highlighted. In addition, the biological activities (antimicrobial, antimalarial and anticancer) of the oils isolated from selected South African aromatic plants (e.g. Vitex spp., Salvia spp.) and the problems encountered when investigating their biological properties will be discussed. In situ and ex situ soil respiration in natural, invaded, and cleared toposequences in the Fynbos Biome O.K. Kambaj a, S.M. Jacobs a, K.B. Mantlana b a Department of Conservation Ecology and Entomology, Stellenbosch University, Private Bag X1, Maitieland 7602, South Africa b Climate Change and Bio-adaptation Division, South African National Biodiversity Institute, Kirstenbosch Research Centre, Private Bag X7, Claremont 7735, Cape Town, South Africa A. mearnsii, Acacia longifolia, and Acacia dealbata are among the most widespread alien invasive plants in South Africa and are often located within riparian catchments with extensive woody stands that dominated areas. These invasions may be significant to the overall catchment carbon cycling as soils are often high in soil organic matter and elevated biological productivity due to the availability of nutrients and water in riparian environments. As such seasonal soil respiration measurements were conducted in selected riparian ecotones of the Western Cape, South Africa, with differing invasion status: natural, invaded, and cleared riparian zones. Soil respiration at all sites and within all landscape positions showed significant seasonality, with highest and lowest values observed during the warm and dry season and the wet season, respectively. Of all environmental factors, Rs were most closely related to soil temperature, while high soil water content during the wet season seemed to inhibit soil respiration. In general soil water content alone was poorly correlated to Rs while a combination of both factors provided a strong relationship with soil respiration. Overall, Rs rates were significantly greater (P b 0.05) in the invaded sites compared to the natural and cleared sites with dry banks showing highest soil respiration rates, followed by wet banks and the terrestrial area. Within invasion status, mean daily soil respiration ranged from 0.70 to 3.50 g C m - 2 day - 1 in the natural, 1.58 to 6.35 g C m - 2 day - 1 in the invaded, and 0.16 to 3.32 g C m - 2 day - 1 in the cleared sites. Potential soil respiration, determined in soil microcosms incubated in the laboratory, showed significantly higher Rs in the soils from invaded sites on day 7 and day 14. This study contributes significantly to the understanding of soil respiration and factors driving soil respiration in fynbos biome, and across landscapes. The findings in the field suggest that soil microbial activity increases in riparian areas invaded by Acacia species, but upon removal of these woody plants a semblance of the pre-invasion state may return over time, though the work on soil microcosm reveals that some differences may remain. Breeding and pollination systems in Clivia (Amaryllidaceae) I. Kiepiel, S.D. Johnson School of Life Sciences, University of KwaZulu-Natal Pietermaritzburg, Private Bag X01, Scottsville 3209, South Africa Clivia (Amaryllidaceae), a small genus of evergreen perennials endemic to southern Africa, has received considerable SAAB Conference Abstracts horticultural and taxonomic attention. Most of the species possess pendulous tubular flowers and are thought to be pollinated by birds. Clivia miniata is recently diverged and has uprighttrumpet shaped flowers consistent with butterfly pollination. This study investigates the reproductive biology of C. miniata and the robust form of Clivia gardenii, also known as Clivia robusta. We document the self-incompatibility systems, floral traits, pollinators, and natural levels of fecundity in these species, and interpret the findings in the context of the phylogeny of Clivia and its close relatives. Aloe section Purpurascentes: The need for a new classification R.R. Klopper a,c, O.M. Grace b, A.E. Van Wyk c, G.F. Smith a,c a Biosystematics Research & Biodiversity Collections Division, South African National Biodiversity Institute, Private Bag X101, Pretoria 0001, South Africa b Jodrell Laboratory, Royal Botanic Gardens, Kew TW9 3AB, Surrey, United Kingdom/Marie Curie Fellow, Department of Medicinal Chemistry, University of Copenhagen, Universitetsparken 2, Copenhagen 2100, Denmark c H.G.W.J. Schweickerdt Herbarium, Department of Plant Science, University of Pretoria, Pretoria 0002, South Africa Southern Africa is a center of diversity for the genus Aloe L. and the region harbors ± 150 members of this genus that has ± 600 species in total. Many societies utilize aloes for a multitude of biocultural uses, and these succulent plants are immensely popular among plant collectors and horticulturalists. Aloe section Purpurascentes Salm-Dyck is restricted to South Africa and Namibia and is characterized by acaulescent or caulescent plants with densely rosulate ensiform leaves and cylindrical flowers with free segments in cylindrical to conical racemes on simple or up to 8-branched inflorescences. Currently this section is usually treated as comprising six species, namely Aloe framesii L.Bolus, Aloe gariepensis Pillans, Aloe khamiesensis Pillans, Aloe knersvlakensis S.J.Marais, Aloe microstigma Salm–Dyck and Aloe succotrina Weston. A taxonomic revision of Aloe section Purpurascentes is underway as differing views regarding the demarcation of species exist. Matters in need of clarification include: populations of A. microstigma in southern Namibian were described under the name Aloe juttae Dinter in 1923, but were alleged to be conspecific with A. microstigma in 1974; A. khamiesensis is sometimes included as a synonym of A. microstigma subsp. microstigma while A. framesii is reduced to subspecific rank [A. microstigma subsp. framesii (L.Bolus) Glen & Hardy]. Furthermore, several morphologically distinct populations of aloes belonging to this section, which warrant possible description as new taxa, are known. New comparative data will be presented based on field studies, evidence from morphology, ecology and biogeography, as well as DNA-based phylogenetic analyses. 193 ‘Toxic nectar’: harmful and beneficial effects of nicotine on an important pollinator, the African honeybee A. Köhler, C.W.W. Pirk, S.W. Nicolson Department of Zoology and Entomology, University of Pretoria, Pretoria 0002, South Africa Nicotine, best known from the Solanaceae, is a plant defense metabolite and highly toxic to most herbivores. The presence of nicotine in floral nectar and pollen seems paradoxical, and the use of nicotine and neonicotinoid insecticides on agricultural crops has been suggested to contribute to the pollinator declines that are currently observed internationally. We examined the effects of nectar nicotine on honeybee (Apis mellifera scutellata) foraging choices and longevity. Using preference tests on freeflying honeybees, we showed that the dose-dependent deterrent effect of nicotine is stronger in more dilute nectars. Secondary metabolites (SM) may act as partial repellents that keep pollinators moving between plants and ensure outcrossing. Plants with nectar SM may be more attractive to pollinators when flowering in isolation or secreting concentrated nectar, and pollinators can avoid intoxication by foraging on multiple nectar sources. We found that caged honeybee worker groups tolerate naturally occurring nectar nicotine concentrations (≤30 μM) in 0.63 M sucrose, but survival decreased on high dietary nicotine (300 μM). Honeybees injected with E. coli lipopolysaccharides showed even lower survival when fed nicotine, suggesting that the combined effect of immune challenges and dietary toxins can be detrimental to colony fitness. However, antimicrobial properties of nicotine may also be beneficial to honeybees: weak workers (possibly affected by a bacterial brood disease) and workers infested with parasitic Varroa mites (known to transmit viral diseases) demonstrated prolonged survival on nicotine diets. A possible exploitation of nectar SM for therapeutic purposes may help to explain the role of these compounds in mediating interactions between plants and their pollinators. The Carotenoid Cleavage Dioxygenase (CCD) gene family in Vitis vinifera L. J.G. Lashbrooke, S.J. Dockrall, P.R. Young, M.A. Vivier Institute for Wine Biotechnology, Department of Viticulture and Oenology, Stellenbosch University, Matieland 7602, South Africa In plants carotenoids perform crucial roles in photosynthesis, and also serve as the precursors for apocarotenoids: a group of compounds with diverse biological functions. Enzymatic cleavage of carotenoids by the carotenoid cleavage dioxygenase (CCD) family has been shown to produce volatile flavor and aroma apocarotenoid compounds (e.g. β-ionone, geranylacetone, pseudoionone, α-ionone and 3-hydroxy-βionone), as well as the phytohormone, strigolactone. Here we identify and characterize the grapevine CCDs involved in 194 SAAB Conference Abstracts apocarotenoid production: CCD1, CCD4a and CCD4b. VvCCD1 has previously been observed to catalyze the in vitro cleavage of zeaxanthin and lutein while we show that it is additionally able to cleave β-carotene. V. vinifera lines were transgenically altered for CCD1 expression through an RNAi-mediated gene silencing strategy and overexpression of the CCD1 gene. A transgenic grapevine population showing a 12-fold range of VvCCD1 expression was generated and metabolically characterized. Photosynthetic tissue (leaf) from these lines was analyzed for carotenoid and apocarotenoid content via RP-HPLC and HS-SPME-GC/MS, respectively. Results indicate that a large amount of control is exerted on VvCCD1 activity, both post-transcriptionally and possibly by means of subcellular compartmentalization. Since weak correlation between VvCCD1 gene expression and apocarotenoid production was observed, it appears that the in planta action of VvCCD1, certainly in photosynthetic tissue, is distinct from the demonstrated in vitro activity. Identification, isolation, expression and functional characterisation of VvCCD4a and -4b provide alternative mechanisms for carotenoid cleavage in V. vinifera L. and an explanation for the divergence between the reported in vitro and the in vivo activities of VvCCD1. The systematic value of flower structure in Crotalaria and related genera of the tribe Crotalarieae (Fabaceae) M.M. Le Roux, B.-E. Van Wyk Department of Botany and Plant Biotechnology, University of Johannesburg, P.O. Box 524, Auckland Park 2006, Johannesburg, South Africa Molecular systematics have recently provided a major step toward a profound insight into generic relationships, thereby creating the opportunity to re-evaluate the taxonomic and functional significances of flower structure in the tribe, with emphasis on the large genus Crotalaria. Flowers in the tribe Crotalarieae are generally adapted to bee pollination mechanisms. A representative sample of flowers from 211 species was dissected to record morphological character states. Six structural–functional flower types were identified: (1) pump; (2) gullet; (3) hugging; (4) saddle; (5) tunnel and (6) brush (saddle and tunnel types described here for the first time). Crotalaria uniquely has the brush type; specialized flowers characterized by a rostrate keel, highly dimorphic anthers, stylar trichomes and four types of elaborate callosities on the standard petal: (1) ridge callosities – vertical swellings on blade and claw; (2) disc callosities – sub-circular swellings on the blade; (3) columnar callosities – cylindrical protruding appendages on the blade; and (4) lamelliform callosities – plate-like protruding appendages on the blade. Remarkably, Crotalaria and Bolusia are the only genera of the tribe Crotalarieae with callosities present in all of the species. In other genera, callosities are generally absent or infrequent. Trends toward specialization are apparent as assemblages of specialized flower characters; individual characters are labile and diagnostically less valuable. Specialized characters often appear to be non-homologous and a result of convergence. Unique combinations of flower characters are often useful to support current generic concepts in Crotalarieae. The shape of the callosities in Crotalaria is diagnostically important to distinguish between unspecialized and specialized infrageneric groups and is congruent with the molecular phylogeny. Regulation of moss development by strigolactones B. Lebouteiller, C.W. King, J. Kossmann, P.N. Hills Institute of Plant Biotechnology, Department of Genetics, University of Stellenbosch, Private Bag X1, Matieland 7602, South Africa Physcomitrella patens, an ephemeral moss widely distributed in temperate zones, is an emergent model for non-vascular plant biology. Because of its simple structure and the intermediate place of mosses in the plant phylogeny, it can be used as a model system for plant growth studies. In the gametophyte stage, the moss colony is formed by two types of filaments, the chloronemata and the caulonemata, with respectively assimilatory and adventitious roles. Plant hormones, particularly auxin, act as internal signals to regulate cell differentiation. The predominance of one filament type over the other is also influenced by external factors including nutrition status, such as the presence of sugars or the source of nitrogen, and light intensity. Analysis of a P. patens mutant deficient in strigolactone biosynthesis suggested that strigolactones, like auxin, inhibit protonemal branching. Moreover, the synthetic strigolactone analog GR24 restores the wild-type phenotype when applied to the mutant, as in Arabidopsis or rice strigolactone-deficient mutants. In higher plants, strigolactones participate in the hormonal network which regulates shoot branching and root architecture. Moreover, their effects on the plant development seem to be highly dependent on the environmental conditions, especially nutrient availability in soils. The place of strigolactones in this complex signal network might be conserved in nonvascular plants. Our study aims to better understand the roles of strigolactones in conjunction with other factors regulating the differentiation of moss filaments. For this, we compared moss development on different media, with or without GR24. We have found that some, but not all, hormone effects depend on the medium composition. This new finding suggests that this model system is suitable to investigate the integration of external and internal signals regulating plant development. How do bird pollinators respond to nectar containing secondary metabolites? S. Lerch-Henning, S.W. Nicolson Department of Zoology and Entomology, University of Pretoria, Pretoria 0002, South Africa SAAB Conference Abstracts The function of nectar is to reward pollinators. Plants defend themselves against herbivores by producing secondary metabolites (SM) and these are also present in nectar of at least 21 plant families. We need to better understand the effects of SM in nectar on pollinating animals. We investigated how specialist (white-bellied sunbirds, Cinnyris talatala) and generalist bird pollinators (dark-capped bulbuls, Pycnonotus tricolor) respond to fresh and artificial nectar containing SM. Erythrina is an important bird-pollinated genus in Africa and the Americas: leaves and seeds are rich in alkaloids and nectar in amino acids. When offered pure nectar of Erythrina caffra and Erythrina lysistemon in choice tests, sunbirds rejected the nectar of Erythrina species but bulbuls did not. Our experiments with artificial nectar used nicotine, an alkaloid of the Solanaceae and present in nectar of Nicotiana spp. (3–30 μM). Firstly, the preference for different nicotine concentrations (0.1–300 μM) in different sucrose concentrations (0.25 and 1 M) was tested. Birds were deterred by high nicotine concentrations but higher sucrose concentration led to higher nicotine intake, more so in sunbirds than in bulbuls. Secondly, we tested if nicotine influences the feeding behavior and patterns of white-bellied sunbirds. In the presence of nicotine, sunbirds showed better compensatory feeding at higher sucrose concentrations. Feeding frequency, total time spent feeding and mean duration of feeding events decreased significantly at a high nicotine concentration (50 μM). If plants have nectar containing SM, generalist pollinators will be less deterred than specialist pollinators but the sugar concentration of nectar can influence this response. High levels of SM had a negative effect on the feeding behavior of a specialist pollinator, and we did not see the increase in feeding frequency which might translate to more efficient pollination. Systematics of the early diverging Apiaceae tribe Annesorhizeae with emphasis on the South African genera A.R. Magee a,b, A.N. Nicolas c, P.M. Tilney b, B.-E. Van Wyk b, G.M. Plunkett c a Compton Herbarium, South African National Biodiversity Institute, Private Bag X7, Claremont 7735, Cape Town, South Africa b Department of Botany and Plant Biotechnology, University of Johannesburg, P.O. Box 524, Auckland Park 2006, Johannesburg, South Africa c Cullman Program for Molecular Systematics, The New York Botanical Garden, 2900 Southern Blvd., Bronx NY 10458–5126, USA Annesorhizeae is an early diverging tribe belonging to the family Apiaceae. The tribe forms part of a paraphyletic assemblage referred to as the protoapioids, defined by the presence of scattered druse crystals of calcium oxalate in the mesocarp of the fruit. The tribe currently comprises six genera, four of which are endemic to South Africa. Within the tribe Annesorhiza, Chamarea, and Itasina have been shown to form a 195 strongly supported clade. The three genera are herbaceous perennials with hysteranthous, summer-deciduous leaves and periodically-replaced fleshy roots. The hysteranthous leaves (withering or absent at anthesis), coupled with the poor collection record and the need to either return to the population at least twice or to cultivate them in order to obtain complete vegetative and reproductive materials, has resulted in the number of species within these genera being greatly underestimated. As part of a re-assessment of generic boundaries within the Annesorhiza clade, extensive field excursions over the last few years have been undertaken in order to obtain complete material for morphological, anatomical and molecular phylogenetic studies. This has resulted in the clarification of species concepts and affinities and several new species have been identified. Within Annesorhiza, the number of species has almost doubled (12 to 21) and includes two species previously assigned to the genus Peucedanum. The number of species within Chamarea has also doubled with at least five new species awaiting formal description. Generic delimitations of the three genera are explored through phylogenetic analyses for 51 accessions representing 18 spp. of Annesorhiza, 9 spp. of Chamarea, 1 sp. of Itasina and two outgroup species (Astydamia latifolia, Molopospermum peloponnesiacum). Resolution within Annesorhiza was poor, but better resolution within Chamarea was obtained. While the monophyly of Chamarea is well supported, Annesorhiza is shown to be paraphyletic with the monotypic genus Itasina embedded within. Taxonomic studies of Ursinia, parachute daisies, (Asteraceae, Anthemideae) in Namaqualand, South Africa A.R. Magee a,b, J.S. Boatwright a,b, L. Mucina c a Compton Herbarium, South African National Biodiversity Institute, Private Bag X7, Claremont 7735, Cape Town, South Africa b Department of Botany and Plant Biotechnology, University of Johannesburg, P.O. Box 524, Auckland Park 2006, Johannesburg, South Africa c Department of Environment & Agriculture, School of Science, Curtin University of Technology, G.P.O. Box U1987, Perth WA 6845, Australia Ursinia is a mainly southern African genus (1 species extending to Ethiopia) comprising ca. 39 species. They are easily recognized by their often large showy ray florets, paleate involucre, scarious involucral bracts and fruit crowned by a pappus of large, white spreading scales. The latter character gives rise to the common name, parachute daisy. The species are currently divided into two subgenera, Ursinia and Sphenogyne, distinguished most readily by the presence or absence of appendages on the paleae. While preparing the treatment of Ursinia for Greater Cape Plants II: Namaqualand-southern Namib and western Karoo, a high percentage of misidentified specimens, particularly from Namaqualand, were noted in the herbarium record as well as an undescribed species uncovered 196 SAAB Conference Abstracts from the Kamiesberg. In particular, the delimitation of Ursinia anthemoides and Ursinia calenduliflora was seen to be problematic. This necessitated a study of the species from this region, the results of which are presented herein. Eight species are here recognized, two from subgenus Sphenogyne and six from subgenus Ursinia. The species can be distinguished by a combination of their life history, presence or absence of appendages on the palea, and shape of the involucral bracts and their scarious apices. Towards the in vitro generation of somaclonal variant plants of sugarcane (Saccharum spp. hybrids) for tolerance to Fusarium sacchari toxins T. Mahlanza a,b, S.J. Snyman a,b, M.P. Watt b, R.S. Rutherford a a South African Sugarcane Research Institute, Private Bag X02, Mount Edgecombe 4300, KwaZulu-Natal, South Africa b School of Biological and Conservation Sciences, Private Bag X54001, University of KwaZulu-Natal, Durban 4000, South Africa The fungus F. sacchari causes stem rot in sugarcane and the toxicity of the isolate PNG40 to the stalk borer Eldana saccharina renders it potentially useful as an endophytic biocontrol agent of this lepidopteran pest. However, its usefulness is restricted due to its pathogenicity on sugarcane. To produce sugarcane lines tolerant to toxins produced by F. sacchari, chemical mutagenesis and in vitro selection using F. sacchari culture filtrates (CF) were utilized. Various selection treatments were established. The first determined the effect of 0–100 ppm CF and at which of the in vitro culture developmental stages (embryo maturation, embryo germination and plantlets) they were most effective. Incorporation of CF in the media at either embryo maturation or germination stages resulted in significant callus necrosis, and consequent decreased plantlet yield; percentage callus necrosis was highest with the latter treatment. Another selection treatment established that root re-growth in plantlets with trimmed roots was inhibited by 750-1500 ppm CF. The third selection treatment involved immersing in vitro plantlets in varying concentrations of F. sacchari conidial suspensions, resulting in 33.3% and 100% mortality from the 10 3 and 10 5 conidia/ml treatments, respectively. To obtain somaclonal variants, chemical mutagenesis was carried out using ethyl methanesulphonate (EMS). Calli and potential tolerant plants were selected using the established CF and inoculation treatments. In order to confirm tolerance to PNG40, plants that survived all the in vitro CF selection pressures were inoculated with F. sacchari conidia and are currently being observed for disease symptom development and endophytic colonization. Future work includes verifying of fungal colonization by staining and re-isolation of PNG40 from plant tissue and molecular analysis of isolates using inter-simple sequence repeat (ISSR) polymorphisms. Update on the maize eQTL project Maize eQTL project consortium Department of Plant Science, Forestry and Agricultural Biotechnology Institute (FABI), University of Pretoria; PANNAR SEED Pty (Ltd.), Greytown; African Centre for Crop Improvement, University of KwaZulu-Natal Pietermaritzburg; Centre for Proteomic and Genomic Research, Cape Town The maize eQTL project addresses the broad hypothesis that phenotypes are controlled to some extent by gene expression differences between genotypes. The agricultural problem that the project is focusing on is gray leaf spot (GLS) disease of maize, caused by the fungus Cercospora zeina. GLS is an economically important constraint for commercial as well as subsistence maize farmers in southern Africa. The project's main aims are to develop improved maize varieties with quantitative resistance to GLS as well as gain an understanding of the molecular basis of this type of resistance, particularly the role of gene regulation. The development of hybrid maize suitable for agro-ecological zones in southern Africa will be discussed as well as an update on the characterization of gene expression differences identified using an eQTL pipeline developed inhouse. Antibacterial, cytotoxic and mutagenic effects of five Ochna species T.J. Makhafola, L.J. McGaw, J.N. Eloff Phytomedicine Programme, Department of Paraclinical Sciences, University of Pretoria, Private Bag X04, Onderstepoort 0110, South Africa The antibacterial activity and number of antibacterial compounds present in the acetone leaf extracts of Ochna natalitia, Ochna pretoriensis, Ochna pulchra, Ochna gamostigmata, and Ochna serullata, against S. aureus, E. coli, Enterococcus faecalis and P. aeruginosa were determined using the serial dilution microplate assay and bioautography respectively. Some of the Ochna species are traditionally used by the Zulu tribe of South Africa for the treatment of dysmenorrhea, fertility problems, diarrhea, hemorrhoids, stomach pains and gangrenous rectitis. The cytotoxic effects of the extracts and selective index values were also determined in monkey kidney cells (Vero), human hepatocellular carcinoma cells (C3A) and bovine dermis cells using the MTT assay. Furthermore, their potential mutagenic effects were determined using the Ames test (Salmonella typhimurium TA98 and TA100). The MIC values of the five extracts ranged from 39 to 1250 μg/ml. Bioautography showed that each extract had at least 1 antibacterial compound and O. gamostigmata had at least 4 active compounds. The IC50 values of the extracts ranged from 26 to 99 μg/ml. Overall all the plant extracts had low selective index values (SI) with SI ≤ 1.3. This is a clear indication of non-selective toxicity i.e. extracts are toxic to bacteria as well as mammalian SAAB Conference Abstracts cell lines. None of the extracts was mutagenic (mutagenic index values ≤ 1.59 for TA98 and ≤0.92 for TA100). As a result the extracts may have limited application as ingestible/intravenous therapeutic agents. It may be useful to evaluate acute toxicity in animal studies because cellular toxicity does not always equate to in vivo toxicity. However, the extracts may be useful for the treatment of topical bacterial infections. DNA barcoding medicinal plants of South Africa L.T. Mankga a,b, A.N. Moteetee a,b, O. Maurin a,b, M. Van der Bank a,b a African Centre for DNA Barcoding, University of Johannesburg, P.O. Box 524, Auckland Park 2006, Johannesburg, South Africa b Department of Botany and Plant Biotechnology, University of Johannesburg, P.O. Box 524, Auckland Park 2006, Johannesburg, South Africa The market and public demand for medicinal plants over the past few decades has increased dramatically with more than 1000 plant species actively traded for medicinal purposes throughout South Africa. Intensive harvesting of wild materials is now acknowledged as a serious threat to biodiversity in this country. Also the substitution of a valuable commodity (medicinal plant) by a cheaper alternative (other plant species), either inadvertently due to misidentification, or deliberately to cheat consumers, raises some serious concerns as these adulterants may not be as effective medicinally or may even be toxic and cause harm to consumers. To add to the problem many species are either traded as dried leaf, root, bark products, or extracts and their identification becomes problematic. In the current study we targeted the most commonly used medicinal plants in South Africa and produced a set of herbarium identified vouchers, a set of barcodes for fast and easy DNA-based species identification (rbcLa, matK, ITS, trnH-psbA), and illustrations on how customs officers could use DNA barcoding to identify plant fragments from species in which trade is controlled by the Convention on International Trade of Endangered Species (CITES). Fly pollination in the achlorophyllous orchid Gastrodia similis: does Gastrodia provide a breeding site for its insect pollinator? F. Martos a, T. Pailler b, B. Bytebier a, S.D. Johnson a a School of Life Sciences, University of KwaZulu-Natal Pietermaritzburg, Private Bag X01, Scottsville 3209, South Africa b UMR 53 Peuplements Végétaux et Bioagresseurs en Milieu Tropical, Université de La Réunion, 15 av. René Cassin, 97715 Saint-Denis cedex 9 Among the vast diversity of angiosperms, only a few taxa are known to have engaged in a mutualistic interaction with insect pollinators by providing them a breeding site, such as in 197 the case of some Ficus (Moraceae), Yucca (Agavaceae) and Aristolochia (Aristolochiaceae) species. Orchidaceae are known for a high diversity and specialization of pollination syndromes. We specifically report a recent pollination study on the tropical, achlorophyllous orchid G. similis, which is endemic to La Réunion Island (Mascarene Archipelago). This orchid attracts drosophilid flies for pollination by producing volatile compounds that mimick fruit odor. We suggest that this nectarless orchid rewards its insect pollinators by providing breeding site. Evaluating antioxidant activity and cytotoxicity of the selected South African medicinal plant species N.A. Masevhe a,b, A. Aroke a, L.J. McGaw a, J.N. Eloff a a Phytomedicine Programme, Department of Paraclinical Sciences, Faculty of Veterinary Science, University of Pretoria, Private Bag X04, Onderstepoort 0110, South Africa b Department of Botany, School of Mathematics and Natural Sciences, University of Venda, Thohoyandou 0950, South Africa Fourteen different plant species were evaluated for their antioxidant potential using three methods, namely DPPH (1,1diphenyl-2-picrylhydrazyl radical), ABTS + (2,2′ azinobis-(3ethylbenzthiazoline-6-sulfonic acid)), and ferric reducing antioxidant power (FRAP). They were also evaluated for their in vitro toxicity against Vero cell lines using MTT assay ((3(4,5-dimethylthiazolyl-2)-2,5-diphenyltetrazolium bromide). Four plant species (29%): Spilanthes acmella, Schkuhria pinnata, Osyris lanceolata and Schotia brachypetala exhibited high cytotoxic activity against Vero cell lines and had IC50 values of 13.7 ± 0, 19.88 ± 0.001, 21.62 ± 0.007 and 28.34 ± 0.001 respectively. However, the IC50 values of these plant extracts were higher than that of the positive control, Doxorubicin which was 9.87 ± 0 μg/ml. Plant species that was relatively non-toxic was Faurea saligna with IC50 value of 201.2 ± 0.004 μg/ml. The rest of the plant species (64%) had moderate cytotoxicity activity (30 μg/ml b IC50 b 100 μg/ml). Plant species that had a high level of antioxidant activity in both DPPH, ABTS and FRAP were O. lanceolata, F. saligna, Acacia caffra and Richardia brasiliensis; and Hippocratea longipetiolata had potent antioxidant activity in DPPH and ABTS methods while S. brachypetala exhibited radical scavenging efficiency in DPPH assay only and Elaeodendron transvaalensis had a reducing power activity in FRAP assay only. These plant species had less antioxidant activity than the controls used. The rest of the plant species had weak antioxidant activity. The results obtained in this study revealed that a high proportion of plant species (93%) contained cytotoxic compounds in their crude extract. On the other hand, medicinal plant species tested in this study showed some free radical scavenging activities using three different methods and can be considered as promising sources of natural antioxidants for medicinal uses. 198 SAAB Conference Abstracts Long-term vegetation change (1900–2010) in the Karoo Midlands biomes with climate and land use as drivers change M.L. Masubelele a,b, M.T. Hoffman b, W.J. Bond c a South African National Parks, Cape Research Centre, Scientific Services: Cape Node, End of Tokai Road (West), Tokai 7945, South Africa b University of Cape Town, Plant Conservation Unit, Botany Department, Rondebosch 7701, Cape Town, South Africa c University of Cape Town, Botany Department, Rondebosch 7701, Cape Town, South Africa Global climate predictions suggest aridification due to drought in the central interior of South Africa. Biomes in this region are expected to undergo dramatic decline in cover of grasses as shrubs spread from the Nama-Karoo into the Grassland biome. Long-term changes in the vegetation within biomes of the Eastern Karoo Midlands Region were studied using historically repeated photography. The aim of the study was to understand the direction of change and also quantify the nature of change for the past 100 years. Using firstly, historical changes in climate variables such as rainfall, drought, temperature and drought were analyzed, secondly, changes in stocking rate between 1910 and 1996 were assessed. Thirdly, 65 repeat photographs were taken within the region and analyzed in terms of the major changes that have occurred within key landform units of the area (e.g. slopes, plains and rivers). We calculated the decadal change in the cover of grasses, dwarf shrubs, tall shrubs and total cover within each landform and biome. Results showed no long-term change in annual rainfall and drought incidence while temperature had increased and evaporation rate was variable. Namakaroo biome sites showed an increase in the incidence of wet periods and an increase in early seasonal rainfall while the Grassland and the Albany thicket biomes showed no significant changes. Stocking rates within all three biomes declined in the 20th century. Grass cover increased substantially across the region while dwarf shrubs declined in the Nama-Karoo and Grassland biomes. The cover of Tall shrubs increased in Grassland and Albany thicket biomes. Historical accounts of the region's climate and land use are important since they help to determine the direction and trajectory of change. Trajectories of change are opposite in sign to what is anticipated in the latter part of the 21st century. A long-term monitoring approach, incorporating historical assessment is needed in order to understand how landscape level processes affect human and ecosystem wellbeing. Bapedi traditional healers in the Limpopo Province, South Africa K.M. Mathibela a, S.S. Semenya a, M.J. Potgieter a, B.A. Egan a, H.J. Du Plessis a, L.J.C. Erasmus b a Departments of Biodiversity and bPhysiology and Environmental Health, School of Molecular and Life Sciences, University of Limpopo, Private Bag X1106, Sovenga 0727, South Africa This survey documented aspects related to Bapedi traditional healers' practice such as their social characteristics and knowledge of relevant legislation and conservation. Sixty four traditional healers were surveyed via a semi-structured questionnaire across the whole of the Limpopo Province. Results showed that the vast majority of traditional healers are male, aged between 41 and 50, with more than 30 years of experience in traditional healing. The majority have no formal education, with a minority that managed to reach secondary school. Because of this low level of literacy they tend to shy away from sources of written information, with the result that none of the questioned healers had any knowledge of the various national or provincial environmental legislations. This had a knock on effect in their view of anything formal, with traditional healers tending to view conservation efforts that involve procedures such as permits as obstacles to their practice. Rituals play an integral part of traditional healing, especially prior to plant harvesting. Ancestral guidance stands central in traditional healing. For example the ancestors are consulted when information is shared; to determine the efficacy of their medicine and to obtain healing knowledge. An ethnobotanical survey of mosquito repellent plants in uMkhanyakude District, KwaZulu-Natal Province, South Africa E.J. Mavundza a,b , R. Maharaj a, J.F. Finnie b, G. Kabera c, J. Van Staden b a Malaria Research Unit, Medical Research Council, 491 Ridge Road, Overport, Durban 4001, South Africa b Research Centre for Plant Growth and Development, School of Life Science, University of KwaZulu-Natal Pietermaritzburg, Private Bag X01, Scottsville 3209, South Africa c Biostatistics Unit, Medical Research Council, 491 Ridge Road, Overport, Durban 4001, South Africa An ethnobotanical survey of plants used for repelling mosquitoes was carried out in uMkhanyakude district, KwaZuluNatal Province, South Africa. The specific objectives of this survey were to (1) identify plant species and their parts being used; (2) determine the condition of plant material used and the method of application. Data was collected from 60 respondents in five villages in the district using standardized and pretested questionnaires. The study revealed that 13 plant species are used in the study area to repel mosquitoes; 2 of the plants remain to be identified. The identified plant species were belonging to 11 genera from 9 families. Meliaceae and Anacardiaceae were the most represented families with two species each. The most frequently recorded species were Lippia javanica (91.67%), followed by Aloe ferox (11.67%), Sclerocarya birrea (5%), Melia azedarach (3%), Balanite maughamii (3%) and Mangifera indica (3%). Leaves were the most (38%) common plant part used. The majority (82%) of the plant parts were used in a dry state. Burning of plant materials to make smoke was the most (92%) common method of application. Nine SAAB Conference Abstracts plant species, namely: A. ferox, Calausena anisata, Croton menyharthii, S. birrea, B. maughamii, Olax dissitiflora, Trichilia emetic, M. indica, and Atalaya alata are documented for the first time as mosquito repellents. This documentation provides the basis for further studies in developing new, effective, safe and affordable plant-derived mosquito repellents especially for Africa where malaria is highly prevalent. The study also plays a part in documenting and conserving traditional knowledge of mosquito repellent plants for future use. Heterologous expression of RANTES analogues in Lycopersicon esculentum Mill K.G. Mawela a,b, E. Chakauya b, R. Chikwamba b a Phytomedicine Programme, University of Pretoria, Private Bag X04, Onderstepoort 0110, South Africa b CSIR Biosciences, P.O. Box 395, Pretoria 0001, South Africa AIDS is one of the most severe, deadly diseases that claimed lives of many people across the globe. An estimate of 42 million people are found to be living with HIV/AIDS worldwide, and more than 3 million die every year from AIDS-related sicknesses. Women are the most susceptible people of the pandemic. Hence there is an urgent need for microbicides research intervention. RANTES analogues are natural ligands for the CC chemokine receptors such as CCR5 which block HIV infection and have been found to be effective ingredients for microbicides. The current study investigated the expression of RANTES analogues in plants as an alternative production system for the microbicides. Two RANTES analogues were transiently expressed in L. esculentum Mill via agrobacteriummediated transfection. Magnifection system was used to deliver the RANTES constructs in L. esculentum species. The RANTES genes were successfully transfected into four developmental stages of mature tomato fruits for protein expression. Protein expression was evaluated by ELISA and was detectable from 3 to 9 day post infiltration (dpi). The highest expression level was obtained in apoplast at 9 dpi. A gradual decrease in the expression level was observed from green to red tomato fruits per construct. 5P12-RANTES construct gave the highest expression level of about 25 ug/kg. Western blot was conducted to confirm the size of recombinant proteins in L. esculentum species which corresponded with the RANTES positive controls. Our results highlight the potential usefulness of plants for the production of RANTES in tomato fruits, a food/feed crop, for preventive intervention of HIV in humans. Genotypic and phylogeographic investigation of indigenous and alien Tamarix species in southern Africa S.G. Mayonde, G. Cron, M. Byrne Department of Animal, Plant and Environmental Science, University of Witwatersrand, Private Bag X3, WITS 2050, Johannesburg, South Africa 199 Tamarix (Tamaricaceae) is from the Old World, but has become naturalized and invaded other parts of the world. Tamarix usneoides is the only species native to southern Africa, but Tamarix aphylla, Tamarix chinensis, Tamarix parviflora and Tamarix. ramosissima have been reported as exotic in South Africa. Tamarix species are hypothesized to be hybridizing among themselves, and T. ramosissima has been declared invasive. T. usneoides is used for phytoremediation in the mines in southern Africa as it hyper-accumulates sulphate and metals from Acid Mine Drainage from Tailing Storage Facilities and excretes gypsum (CaSO4). Tamarix species are morphologically and ecologically similar, making them very difficult to distinguish and hybridization adds to the taxonomic confusion. Identification of Tamarix species in South Africa is of great importance because of the invasive potential of T. ramosissima and also the potential usefulness of T. usneoides. This investigation aims to identify populations of pure T. usneoides that can be cloned for cultivation for phytoremediation on the mines, and to reveal the geographic origin of the invasive species (e.g. T. ramosissima) to facilitate a biocontrol programme. In this study, nuclear and plastid DNA sequence markers are used to characterize southern African Tamarix species and their putative hybrids genetically and to assist in recognition of hybrids. Phylogenetic analyses and analysis of polymorphisms indicate that many of the populations sampled are of hybrid origin, most notably those currently being used on the mines for phytoremediation. Morphological characters are not always reliable detectors of hybridization. Antimycobacterial activity, cytotoxicity and genotoxicity studies of Ptaeroxylon obliquum and Sideroxylon inerme leaf extracts L.J. McGaw, T.J. Makhafola, O.O. Udom, K.T.V. Mayekiso, J.N. Eloff Phytomedicine Programme, Department of Paraclinical Sciences, University of Pretoria, Private Bag X04, Onderstepoort 0110, Pretoria, South Africa Two plant species, namely P. obliquum and S. inerme, were investigated for antimycobacterial, cytotoxic and genotoxic activities following good activity detected in an initial random screening procedure of a large number of extracts. Acetone extracts of the leaves were prepared and tested in vitro for activity against Mycobacterium smegmatis and Mycobacterium bovis BCG. MIC values ranged from 156 to 313 μg/ml. P. obliquum was relatively cytotoxic to human liver (C3A) cells, with an LC50 value of 86 μg/ml. The selectivity index (SI) values for this extract with regard to M. smegmatis and M. bovis BCG were 0.552 and 0.275 respectively. S. inerme was less cytotoxic, with an LC50 value of 1 039 μg/ml, resulting in promising SI values of 6.66 for both M. smegmatis and M. bovis BCG. Neither of the two extracts was mutagenic in the Ames test against S. typhimurium strains TA98 and TA100, without metabolic activation. However, in the comet assay, the two extracts were 200 SAAB Conference Abstracts moderately genotoxic when using tail moment (a measure of both amount of DNA in the tail and distribution of DNA in the tail) as an assessment parameter, with P. obliquum showing a more pronounced effect. This extract may be responsible for the induction of double stranded DNA breaks and may thus be a potential mutagen (with a higher% DNA in the comet tail and short tail length). Isolation of antimycobacterial compounds from these species is currently being undertaken. Analysis of differential gene expression during the early stages of rust infection in a sugarcane breeding population T.T. Mhora a,b, R.S. Rutherford a, D.L. Sweby a, R.M. Jacob a, L. Makome a, J.W. Danson b a South African Sugarcane Research Institute, Private Bag X02, Mount Edgecombe 4300, South Africa b School of Agricultural Sciences and Agribusiness, University of KwaZulu-Natal Pietermaritzburg, Private Bag X01, Scottsville 3209, South Africa Resistant cultivars are the most effective way of controlling brown rust of sugarcane caused by Puccinia melanocephala. Molecular techniques can be used to identify undocumented rust resistance mechanisms, which can then be utilized in breeding strategies to develop cultivars with increased resistance and durability. Suppression Subtractive Hybridization (SSH) was used to identify genes differentially expressed between sugarcane genotypes that are resistant (two groups with different modes of resistance, each group having three genotypes), intermediately resistant and susceptible to rust. Leaves were sampled 48 h after inoculation with P. melanocephala. mRNA for each genotype was purified, pooled into its respective groups and converted into cDNA using the Clontech SMARTer™ cDNA synthesis kit. Two subtracted cDNA libraries were constructed using a PCR-Select™ cDNA subtraction kit. For Library 1 pooled samples of Susceptible and Intermediate resistant genotypes were subtracted from Resistant Group One. For Library 2, Resistant Group Two was subtracted from Resistant Group One. Subtracted cDNA libraries were transformed into E. coli. The cDNA inserted using the pGEM®-T easy vector in individual bacterial colonies was amplified by PCR and showed successfully transformed clones with cDNA inserts ranging from 200-1300 bp. DNA Sequence analysis of inserts and BLAST searches for both libraries revealed that over 70% of the sequences were identified as various disease and drought stress related gene sequences. Library 1 revealed enrichment for serine/threonine kinases, reticulonlike proteins and RNA recognition motifs, domains found in proteins involved in post-transcriptional gene expression processes. The Mob1 gene was also identified in Library 1. Mob1 is known to play a role in hypersensitive responses and in cytokinesis, critical processes in host resistance to pathogens. Processing of Library 2 results is still in progress. These results show the usefulness of SSH in providing information on gene expression in response to brown rust infection. This information could be used to develop markers for resistance, having potential application in the breeding and selection programme. In the right place at the right time: Why some introduced Proteaceae spread at some sites but fail at many others D. Moodley a, J.R. Wilson a,b, S. Geerts a,b, D.M. Richardson a, A.G. Rebelo b a Centre for Invasion Biology, Department of Botany and Zoology, Stellenbosch University, Private Bag X1, Matieland 7602, South Africa b South African National Biodiversity Institute, Kirstenbosch National Botanical Gardens, Claremont, South Africa The success of invasive alien plants is attributed to them overcoming a series of barriers during the introduction–naturalization–invasion process. We explore why certain species are invasive in some locations, but not in others using Proteaceae as a test case. Many species of Proteaceae are used as cut flowers, for hedges and ornamental plants, in landscaping and for food. Consequently, many species of Proteaceae have had a long history of introductions to regions outside their native ranges. Some Australian Proteaceae species are notable invaders, but others are notoriously difficult to cultivate. However, although some species are rather difficult to cultivate, a few of the Proteaceae introduced to South Africa, particularly Hakea salicifolia and Banksia integrifolia, have naturalized or are spreading at some sites, but have failed to naturalize at many other sites. The Protea Atlas and the Southern Africa Plant Invasion Atlas were used as initial sources for obtaining locality information for alien Proteaceae in South Africa. Populations in unmanaged sites were selected, since plants are more likely to spread at these sites. The extent and abundance of planted and self-sown plants were determined. Sampling involved mapping the source population(s), and mapping and categorizing the number of naturalized plants into different size classes, namely seedlings, juveniles and young adults. Data on the presence of herbivory, time since last fire, presence of phytophthora, land use, topography, reason for planting, management, seed viability, rainfall, temperature, elevation and soil type were collected. The status of populations, whether naturalized or non-naturalized, was related to the predictors by means of generalized linear models in order to determine which factors facilitate spread. Preliminary results will be discussed in terms of the importance of site specific factors in predicting the likelihood of a species naturalizing and these factors include climate, disturbance, introduction history and propagule pressure. The use of bioclimatic modelling in predicting the relative invasion success of introduced acacias in southern Africa R.F. Motloung a, M.P. Robertson a, M. Rouget b, J.R. Wilson c,d SAAB Conference Abstracts a Department of Zoology and Entomology, University of Pretoria, Pretoria 0002, South Africa b Department of Plant Science, University of Pretoria, Pretoria 0002, South Africa c Centre for Invasion Biology, Department of Botany and Zoology, Stellenbosch University, Matieland 7602, South Africa d South African National Biodiversity Institute, Private Bag X7, Claremont 7735, South Africa The likelihood of successful establishment of introduced plant species has been predicted using various modeling techniques. Although these models have considerable potential in risk assessment, this has been rarely tested. We aim to determine how useful bioclimatic models are at predicting the establishment or invasion success of introduced plant species and its implications for risk assessment. About 69 Australian Acacia species have been introduced into southern Africa for various purposes, of which 38 species were introduced for government forestry trials. Firstly, we compare the introduction success of each species with respect to climatic suitability. And secondly, for 15 Australian acacias reported to be invasive in Southern African Plant Invaders Atlas (SAPIA), we determine whether bioclimatic models could have successfully predicted their spread. Bioclimatic models were calibrated using occurrence datasets from Australia as the native range, and evaluated in the introduced range using government forestry trials and the Southern African Plant Invaders Atlas. Models were tested against independent records by calculating true skill statistic which quantifies omission and commission errors, sensitivity and specificity. Bioclimatic models suggest that a large portion of southern Africa is climatically suitable for Australian acacias. Overall there was a fair agreement between the models and government forestry trials dataset (specificity of 0.83, sensitivity of 0.68, and TSS score of 0.51). However, the models poorly predicted the distribution of invasive acacias (specificity of 0.23). Antioxidant activities of nine medicinal plants used in treating inflammatory ailments in Zulu traditional medicine of South Africa E. Muleya a,b, A.S. Ahmed b, A.M. Sipamla a , F.A. Mtunzi a, J.N. Eloff b a Vaal University of Technology, Chemistry Department, Private Bag X021, Vanderbijlpark 1900, South Africa b Phytomedicine Programme, Department of Paraclinical Sciences, Faculty of Veterinary Sciences, University of Pretoria, Private Bag X04, Onderstepoort 0110, South Africa Inflammation is a complex interaction between proinflammatory and anti-inflammatory mediators in response to induced negative stimuli in which the former predominates. Many allopathic medications currently used in alleviating inflammation are associated with some major side effects such as intestinal and cardiac toxicities. However, medicinal plants 201 are also used in many traditional practices against inflammatory complications. If the active components present in medicinal plant extract affect the same molecular targets as mainstream interventions with no side effects, such extracts could provide attractive and cost-effective alternatives to the conventional anti-inflammatory agents. Considering the importance of oxidation in inflammatory mechanisms, the free radical scavenging activities of Pentanisia prunelloides, Pomaria sandersonii, Alepidea amatymbica, Gunnera perpensa, Carissa bispinosa, Artemisia afra, Eucomis autumnalis, Ledebouria revoluta and Berkheya setifera used to remedy inflammation in Mabandla Village, KwaZulu-Natal, South Africa was carried out against ABTS ● + and DPPH ● radicals. Results from both assays indicated that some of the plants had good antiradical properties. For DPPH ● radical assay, EC50 values ranged between 1.9 mg/l from L. revoluta crude to 467 mg/l from hexane fraction of C. bispinosa. The trend of activity in ABTS ● + radical scavenging was similar to the DPPH trend. However, P. sandersonii extracts were the most active in this case inhibitory with EC50 values of 1.27 mg/l for crude extract, 1.66 mg/l for DCM and 1.27 mg/l for acetone fraction. C. bispinosa crude extract had the lowest activity against the ABTS ● + and DPPH ● radicals (190.6 mg/l and 25.45 mg/l respectively). The good antiradical results obtained for some of the plants indicate that antioxidant activities may contribute to their antiinflammatory potential, therefore validating their traditional use as therapeutic in inflammatory disorders. Elucidation and characterization of markers for the salicylic acid and methyl jasmonate pathways in Eucalyptus grandis R. Naidoo a, S. Naidoo a, D.K. Berger b, A.A. Myburg a a Department of Genetics and bDepartment of Plant Science, Forestry and Agricultural Biotechnology Institute (FABI), University of Pretoria, Pretoria 0028, South Africa The South African forestry industry relies significantly on the efficient production of various Eucalyptus species primarily for their use in manufacturing wood and paper products. Although these trees are relatively sturdy, they can succumb to diseases caused various pathogens including Chrysoporthe austroafricana. Much of the information pertaining to plant defense stems from model organisms such as A. thaliana and therefore there is a need to investigate this niche in Eucalyptus. Among the plethora of defenses, signaling pathways such as salicylic acid (SA) and methyl jasmonate (MeJA) are triggered and assist in curbing the spread of the pathogen. Each of these signaling pathways initiates the expression of a suite of pathogenesis related (PR) genes which have been shown to be markers for the induction of the signaling pathway. Based on this premise, the aim of this study was to elucidate and characterize the PR genes associated with SA and MeJA in E. grandis. Using the genome of E. grandis and a phylogenetic approach, orthologous markers for the SA (PR1, PR2, PR5) and MeJA 202 SAAB Conference Abstracts (PR3, PR4, LOX) pathway were identified based on Arabidopsis sequences. Expression profiling using Reverse Transcription quantitative PCR (RT-qPCR) was performed with these markers in a dose response and time dependent experiment. The dose response experiment indicated that 5 mM and 100 μM induced the most significant change in transcript expression for the putative marker genes associated with SA and MeJA respectively. Additionally the marker genes supported an antagonistic relationship between SA and MeJA in Eucalyptus as previously described in Arabidopsis. These putative markers were furthermore investigated in Eucalyptus plants challenged with C. austroafricana, which revealed a possible role for SA in the tolerant interaction. This study adds to the current knowledge of defense responses in E. grandis and provides a stepping stone for understanding plant resistance mechanisms to curb future tree diseases. Gene conversion of the ribosomal RNA cistron K. Naidoo a, M.P.A. Coetzee a, E. Steenkamp b, B. Slippers a, M.J. Wingfield a, B.D Wingfield a a Department of Genetics, Forestry and Agricultural Biotechnology Institute (FABI), Faculty of Natural and Agricultural Sciences, University of Pretoria, Pretoria 0002, South Africa b Department of Microbiology, Forestry and Agricultural Biotechnology Institute (FABI), Faculty of Natural and Agricultural Sciences, University of Pretoria, Pretoria 0002, South Africa The nuclear ribosomal RNA cistron, comprising of the 18S5.8S-26S gene regions, is most frequently targeted for phylogenetic reconstruction and DNA based identification in the eukaryotic kingdom. Identity among the numerous tandem repeats of this element are assumed to be maintained through gene conversion. During this process, concerted evolutionary forces are thought to prevent genes within individual repeat elements from accumulating mutations. It is, however, not yet known when during the cell cycle this process occurs. By making use of a fungal model, our overarching aim was to determine if gene conversion in the ribosomal RNA cistron was as a result of meiotic events, mitotic events or a combination of both. Ceratocystis manginecans, a haploid homothallic ascomycete, was found, through routine population studies, to have two distinct sequences within the internal transcribed spacer region of the cistron. These two sequence types were profiled in mitotically and meiotically derived populations using PCR and restriction fragment length polymorphism. The relative ratios of these two sequence types changed during mitosis when the fungal isolates were cultured as well as during meiosis when spores are produced. These changes were shown to occur more frequently during meiosis than mitosis. These results thus provide empirical evidence of gene conversion occurring during both meiosis and mitosis, and not only as previously thought during meiosis. This is the first time that gene conversion of ribosomal RNA repeat elements has been shown experimentally. Phytohormone choice and the in vitro development of eucalypt roots M. Nakhooda a, M.P. Watt a, D. Mycock b a School of Life Sciences, University of KwaZulu-Natal, Durban, South Africa b School of Animal, Plant and Environmental Sciences, University of the Witwatersrand, Johannesburg, South Africa Eucalyptus micropropagation has great potential in supplying large numbers of superior but otherwise difficult-to-root clones for forestry deployment. Studies indicate, however, that micropropagated plants possess an inferior root system once acclimatized, compared with those of seedlings and mini-cuttings. Since adventitious rooting in vitro is often under the influence of empirically-selected exogenous auxins, the specific actions of these auxins on root induction and development needed investigation. The roles of two natural auxins – indole-3-acetic acid (IAA) and indole-3-butyric acid (IBA) – were presently investigated, using two eucalypt clones of differing rooting ability (clone 1 – roots to 87% and clone 2 roots to 45%, when using a standard protocol), in conjunction with the IAA-specific transport inhibitor 2,3,5-triiodobenzoic acid (TIBA). It was found that while IBA was able to induce roots in vitro, subsequent root development and graviperception was dependent on shoot IAA content, as established using gas chromatography-mass spectrometry (GC-MS). However, owing to its greater stability over IAA, IBA remains the preferred auxin for adventitious rooting, particularly for difficult-to-root clones. The apparent inability of poor-rooters to respond to IAA was therefore investigated using clone 2. It was found that this clone was not deficient in auxin perception (using the inhibitor of auxin signal transduction ρchlorophenoxyisobutyric acid – PCIB), nor was its poor rooting properties attributed to auxin conjugation (using the auxin conjugation inhibitor dihydroxyacetophenone (DHAP)). However, using GC-MS, a strong relationship was realized between shoot cytokinin:auxin and rootability. Reducing cytokinins from the pre-rooting culture stages, or using the less stable cytokinin, trans-zeatin, significantly improved the rooting ability of clone 2 (100% with IAA). This indicated that the phytohormones chosen for eucalypt micropropagation should be based on phytohormone properties and interactions, with regard to developmental requirements of shoots and roots, rather than in isolation, based on potency. In vitro propagation of Cyrtanthus species B. Ncube, J.F. Finnie, J. Van Staden Research Centre for Plant Growth and Development, School of Life Sciences, University of KwaZulu-Natal Pietermaritzburg, Private Bag X01, Scottsville 3209, South Africa Crytanthus (Amaryllidaceae) is a genus of perennial geophytes, endemic to the southern African region. In South SAAB Conference Abstracts Africa, the genus represents an important group of monocotyledonous bulbous plants of which the bulbs and flowers are highly sought after for both medicinal and ornamental purposes. Due to their valuable use in traditional medicine and potential for the production of novel alkaloids, the three Cyrtanthus species (Cyrtanthus contractus, Cyrtanthus guthrieae, Cyrtanthus obliquus) have been reported to be declining rapidly in their natural habitats in South Africa. In recognition of this fact, increasing the population of these plant species through cultivation would be an important strategy for meeting a growing demand as well as maintaining an ecological diversity. Twin scales from the three species were cultured on solid Murashige and Skoog (MS) media with concentrations of 6-benzyladenine (BA) (0-17.7 μM) and naphthalene acetic acid (NAA) (0-10.7 μM) under continuous darkness and 16/8 h light/dark conditions. The best shoot initiation responses were obtained on MS medium containing 8.9 μM BA and 5.4 μM NAA under continuous darkness at 25 °C (3.1 shoots/explant) for C. contractus, 4.4 μM BA and 1.1 μM NAA at 25 °C under 16 h light/8 h dark regime (6.3 shoots/explant) for C. guthrieae and 6.7 μM BA and 2.7 μM NAA at 25 °C under 16 h light/8 h dark (1.9 shoots/explant) for C. obliquus. The effects of different concentrations of cytokinins (BA, kinetin and zeatin) on shoot multiplication were evaluated. The developed micropropagation protocols provide rapid and cost effective ways for the conservation and domestication of Cyrtanthus species. Toxicity studies on four Hypoxis species and a commercial herbal mixture A.R. Ndhlala a , R. Anthonissen b, G.I. Stafford c, L. Verschaeve b, J. Van Staden a a Research Centre for Plant Growth and Development, School of Life Sciences, University of KwaZulu-Natal Pietermaritzburg, Private Bag X01, Scottsville 3201, South Africa b Toxicology, Scientific Institute of Public Health, Juliette Wytsmanstreet 14, B-1050 Brussels, Belgium c Botanical Garden and Museum, Natural History Museum, University of Copenhagen, Sølvgade 83, DK-1307 Copenhagen, Denmark Several claims have been made for extracts emanating from Hypoxis species. These include efficacy as stimulant of the immune system, which has led to the species being given credit for its health benefits to HIV/AIDS sufferers. Another claim made for Hypoxis spp. includes their use as agents for slowing down the growth of certain types of cancer, having a positive effect in combating colds and being highly effective in alleviating arthritis. These widespread claims have led to the appearance of commercial preparations made of Hypoxis sp. extracts. Among them the African potato extract TM. Within the genus, two species, Hypoxis hemerocallidea and Hypoxis colchicifolia are particularly popular both as African traditional remedies and for the preparation of herbal teas and tinctures. Using the comet and micronucleus/cytome and neutral red 203 uptake assays, four Hypoxis species commonly used in traditional medicine in South Africa and an unregistered commercial Hypoxis product were evaluated for their potential toxicity. The results reflected lack of toxicity in all four Hypoxis species analyzed as well as in the commercial herbal mixture. It is, however, important to carry out confirmatory tests using other tests such as the VITOTOX® test for toxicity and/or in vivo assays. Perception and concept on diarrhea treatment amongst traditional healers of Vhembe District Municipality, Limpopo (RSA) T.A. Netshivhulana, M.P. Tshisikhawe Department of Botany, University of Venda, Thohoyandou 0950, South Africa The study focused on the perception and the concept of traditional healers on diarrhea in Vhembe District Municipality, Limpopo Province, South Africa. The study dealt with the understanding and belief system towards diarrhea as per the traditional healers' concept. Data was collected through using questionnaires establishing patterns towards description of diarrhea and categories of diarrhea. Dietary requirements for diarrheal patients were also recorded. The study revealed that traditional healers in Vhembe district have a lot of information on the causes as well as categories of diarrhea and dietary requirements of diarrheal patients. The study showed that traditional healers of Vhembe District have a better understanding when it comes to the perception and concept of diarrheal disease. Bee food: The chemistry and nutritional value of nectar and pollen S.W. Nicolson Department of Zoology and Entomology, University of Pretoria, Pretoria 0002, South Africa Bees are herbivorous insects, consuming nectar and pollen throughout their life cycles, and are excellent pollinators as a result. One of the factors contributing to current declines in bee populations may be poor nutrition, due to forage loss and dependence on monocultures, and this may interact with the adverse effects of pesticides and pathogens. I present a brief overview of the chemistry of floral resources for bees and the implications for their nutrition. Nectar is primarily an energy source, but in addition to sugars, contains various minor constituents that may, directly or indirectly, have nutritional significance. Pollen provides bees with the protein, lipids, vitamins and minerals that are essential for larval rearing. Chemical analyses of pollen have tended to focus on the protein component of bee-collected pollens as an index of nutritional quality. However, the substantial nectar content of such samples (~ 50% 204 SAAB Conference Abstracts dry mass) should not be ignored, especially in view of current interest in assessing the nutritional quality of floral resources for bees. Early detection of the new potential invader; Epipremnum aureum (L.) Engl. S.N. Nzama, H.J.N. Sithole Early Detection and Rapid Response Programme (EDRR – funded by Working for Water) South African National Biodiversity Institute, P.O. Box 52099, Berea Road, Durban 4007, South Africa E. aureum (L.) Engl. (Silver vine) is a potential invader recently detected by the Early Detection and Rapid Response (EDRR) programme in KwaZulu-Natal. It is an epiphytic climber from Araceae family and is characterized by remarkable huge leathery leaves with yellow or white marks. This plant is native to Southeast Asia and has spread to tropical areas where it is highly invasive hence poses an invasion threat to South Africa's subtropical coastal areas. E. aureum was introduced for ornamental purposes/as a garden plant where it has escaped to the wild and now is realizing the potential of becoming invasive. Forest margins and disturbed sites are prone to its invasion. In South Africa this species is not yet included in the draft list of declared invaders. In preparation to get it listed, a preliminary survey is conducted to map it in the wild and assess its invasiveness. Biology studies are also done to determine its life/growth form. Nurseries within the South coast in KwaZulu-Natal are surveyed to determine if horticultural trade have a role to play in distributing E. aureum. The purpose of this talk is to highlight our preliminary ecology results and present the nursery survey findings. This talk also serves to motivate for a need of long-term research on ecological studies and control methods for rapid response. A hypothetical Eucalyptus grandis defense model against Leptocybe invasa based on transcriptome sequencing C.N. Oates, A.A. Myburg, B. Slippers, S. Naidoo Faculty of Natural and Agricultural Sciences, Department of Genetics, Forestry and Agricultural Biotechnology Institute, University of Pretoria, Pretoria 0002, South Africa Eucalyptus species are widely used in commercial plantations due to their superior growth, adaptability and wood properties. A number of industries rely on these trees to supply the fiber, pulp and sawn wood for their products. The Eucalyptus gall wasp, L. invasa (Hymenoptera: Eulophidae), was first described in Israel in 2000 following the extensive damage it caused in plantation nurseries. Adults oviposit in young tissue along the midribs, petioles and stems of numerous Eucalyptus species. The larvae are endophytic herbivores whose feeding leads to the induction of gall formation. Severely infested trees show a range of symptoms including a gnarled appearance, stunted growth and death. Variations in resistance and susceptibility have been noted across different Eucalyptus genotypes. There is currently no information available regarding the mechanism of defense in these plants. The aim of this study is to investigate the defense response of a resistant E. grandis clone against L. invasa. Year old E. grandis seedlings were coppiced and maintained in a L. invasa-free environment until sufficient young material had been produced. Three biological replicates of six plants each were naturally infested over seven days. Thereafter, leaf midribs were excised and total RNA was isolated from attacked and control plants for RNA sequencing. Initial analyses have identified 1381 significantly differentially expressed genes from the 44974 current E. grandis gene models. Over representation data appears to support a defense model that includes a number of well described responses, such as the oxidative burst and the jasmonate-mediated signaling pathway. Some other defenses, which are less well characterized in previous studies, include evidence for a gene-for-gene recognition system, the suppression of nutrient availability to the larvae and the induction of secondary metabolism. This research represents the first step toward understanding Eucalyptus resistance against this destructive plantation pest. Anti-inflammatory, genotoxic and phytochemical properties of selected South African medicinal plants used in treating stomach-related ailments A. Okem, J.F. Finnie, J. Van Staden Research Centre for Plant Growth and Development, School of Life Sciences, University of KwaZulu-Natal Pietermaritzburg, Private Bag X01, Scottsville 3209, South Africa Ethyl acetate (EtOAc), ethanol (EtOH) 70% and water extracts of South African medicinal plants used in treating stomach-related ailments were evaluated for their cyclooxygenase-inhibitory activity against COX-1 and -2 isoenzymes. The standard plate incorporation assay for Ames test was used to evaluate the genotoxic potential of the plant extracts. A spectrophotometric method was used to determine the total phenolics, gallotannins, flavonoids and saponins in the evaluated plants. All the EtOAc extracts exhibited percentage inhibition in the range of 50.7 to 94.7% against COX-1 and -2 isoenzymes at 250 μg/ml. All the evaluated plant extracts were non-mutagenic toward S. typhimurium tester strains TA98, TA100 and TA1537 without metabolic activation. Phytochemical analysis revealed relatively high amounts of total phenolics, gallotannins and flavonoids in the evaluated plant extracts. Total and steroidal saponins were detected in two plant samples, Canthium spinosum and Cassinopsis ilicifolia (bark). The general pharmacological activities exhibited by some of the plant extracts in this study warrant their traditional uses in treating stomach-related ailments. Further studies will be aimed at isolation and identification of the bioactive compounds in the evaluated plant species. SAAB Conference Abstracts Antioxidant activity, total polyphenolic content and in vitro inhibition of activity of digestive enzymes significant to diabetes by leaf extracts of ten South African Ficus species O.O. Olaokun a, L.J. McGaw a, J.N. Eloff a, V. Naidoo a,b a Phytomedicine Programme, Department of Paraclinical Sciences, University of Pretoria, Private Bag X04, Onderstepoort, 0110, South Africa b Biomedical Research Centre, Faculty of Veterinary Sciences, University of Pretoria, Onderstepoort 0110, South Africa Hyperglycemia is the hallmark of diabetes mellitus. Postprandial blood glucose levels may be high with normal fasting blood glucose in early diabetes. Continuous elevated blood glucose deteriorates β-cell function by glucose toxicity, which provokes oxidative stress. One way to manage hyperglycemia is to inhibit the activity of α-amylase and α-glucosidase, the enzymes which break down carbohydrate. We investigated the potential of crude acetone extracts of ten South African Ficus species to inhibit the digestive enzyme activities, and the possible relationship between these activities, total polyphenolic content and antioxidant activity. A literature survey revealed that about 10 species are presently reported to have anti-diabetes activity through their glucose lowering activity in alloxan or streptozotocin induced diabetic laboratory animals. In no case were the mechanism(s) involved in the glucose lowering effects elucidated. All the Ficus species we studied had varying polyphenolic contents and antioxidant activity. The crude acetone extract of Ficus lutea had the highest phenolic content (56.85 ± 1.82 mg GAE/g of dry material) and the strongest antioxidant activity with a TEAC value of 4.80 ± 0.90. Generally, no relationship was observed between the total polyphenolic content and the antioxidant activity. The Ficus species weakly inhibited α-glucosidae activity with Ficus sycomorus having the best EC50 (217 ± 69 μg/ml) followed by F. lutea (289 ± 111 μg/ml), but strongly inhibited α-amylase activity with F. lutea having the best EC50 (9± 2 μg/ ml) followed by Ficus craterostoma (11 ± 5 μg/ml). The results of this study revealed that the crude acetone extract of F. lutea is high in total polyphenolic content, antioxidant activity and is a potent inhibitor of α-amylase activity. The polyphenolic compounds present in F. lutea may likely be responsible for the inhibitory activity against the carbohydrate hydrolyzing enzymes. Further work is continuing on this species. Potential of synthesized naphthoquinones for antituberculosis activity C.B. Oosthuizen a, C. Hamilton b, N. Lall a a Department of Plant Science, University of Pretoria, Pretoria 0002, South Africa b School of Pharmacy, Medicinal Chemistry, University of East Anglia, Norwich NR4 7TJ, United Kingdom Mycobacterium tuberculosis is one of the world's biggest killers, with an incident rate of 9.4 million with a death of 205 1.7 million in 2009. Tuberculosis (TB) is also a major problem in South Africa due to the high incidence of HIV/Aids patients. Even though relatively adequate treatments are in place, the emergence of multiple drug resistant (MDR) TB has become a major threat, and thus calls for an urgent search for new and effective treatments. Medicinal plants have been used traditionally to treat the symptoms of TB. Naphthoquinones have been isolated from plant extracts and have shown activity against Mycobacterium previously. Nineteen chemically synthesized naphthoquinone derivatives were used to screen their activity against M. smegmatis and M. tuberculosis, where five of these compounds showed high activity with Minimum Inhibitory Concentrations (MIC's) ranging between 7.8 ug/ml to 200 ug/ml. These five compounds were tested for possible enzymatic mechanism of action utilizing glutathione disulfide reductase (Gtr – human analog) and mycothiol disulfide reductase (Mtr – Mycobacterium analog) assays. None of the samples showed inhibition of Mtr or Gtr but all five samples showed some subversive substrate activity, with Km-values ranging between 0.3 mg/ml to 2 mg/ml. The cytotoxicity of the compounds was evaluated on Vero cells as well as on differentiated U937 macrophages. The South African Biodiversity Information Facility: Data mobilization in South Africa F. Parker-Allie Biodiversity Information Management Directorate, Kirstenbosch Research Centre, SANBI, Cape Town South Africa is one of the world's most mega diverse countries, with a rich biological heritage but, direct and indirect drivers of change, including habitat destruction and degradation, invasive alien species and climate change, threaten the existence of many species in the country. These changes and threats highlight the urgent need to record, monitor and report on biodiversity. The South African Biodiversity Information Facility was initiated to address the country's need for an enabling platform for researchers, policy makers, conservation scientists and practitioners to access, share and disseminate primary biodiversity data while at the same time having access to global information. Currently SABIF serves over 14 million biodiversity data records (including images), using the Darwin Core Standard, with a network of more than 15 organizations which contribute to the programme. Data sharing takes place through both funded and non-funded mechanisms, thereby ensuring that resources are available to initiate digitization activities. A comprehensive policy framework has also been put in place by SANBI, to enable data sharing which takes into account intellectual property rights, citations and sensitive data. The next phase of SABIF looks at strengthening the biodiversity information “strategic partnership projects” with organizations in the country to ensure that data is relevant for both science and policy uptake. 206 SAAB Conference Abstracts Evidence for a re-circumscription of the Thuidiaceae (Bryophyta) in Africa and the East African Islands N. Phephu a,b, A.R. Magee c,d, J. Van Rooy b, A.E. Van Wyk a, D. Garcia-Avila e a Department of Plant Science, University of Pretoria, Pretoria 0002, South Africa b South African National Biodiversity Institute, National Herbarium, Private Bag X101, Pretoria 0001, South Africa c South African National Biodiversity Institute, Compton Herbarium, Private Bag X7, Claremont 7735, Cape Town, South Africa d Department of Botany and Plant Biotechnology, University of Johannesburg, P.O. Box 524, Auckland Park 2006, Johannesburg, South Africa e Facultad de Biologia, Laboratorio de Botánica (Herbario), Universidad Michoacana de San Nicolás de Hidalgo, Av, Fco, J, Mújica s/n Col. Felicitas del Rio, C. P. 58030 Morelia, Michoacán, Mexico The moss family Thuidiaceae consists of about 19 genera and more than 150 species worldwide. The group is characterized by attractive, regularly 2- or 3-pinnate branched stems; uniseriate paraphyllia on stem and branch surfaces; dimorphic stem and branch leaves, a single costa and ornate cells; perfect peristome; asymmetrical capsule; occasionally papillose seta and ciliate inner perchaetial leaf margins. Members of the family are morphologically very similar and exhibit tremendous infraspecific variability. As a result the delimitation of genera and species has been problematic. In an attempt to resolve uncertainties in classification of the group and re-circumscribe the African Thuidiaceae, morphological and anatomical characters of selected Thuidiaceae were studied and reconstructed onto the phylogenetic trees using parsimony. The relationship of the African species of Haplocladium, Hylocomiopsis, Abietinella and Rauiella with other members of the Thuidiaceae is investigated. The exclusion of these genera from Thudiaceae has been suggested by previous studies and a relationship rather with Leskeaceae seems likely. Based on morphological and anatomical data we support their exclusion and recognize only three genera and 16 species of Thudiaceae in Africa. Plant size, stem branching pattern, paraphyllia morphology and ornamentation of leaf cells is shown to be taxonomically useful, particularly in combination at the generic level. How healthy are our honeybees – Health check of a major pollinator C.W.W. Pirk, H. Human Social Insect Research Group, Department of Zoology & Entomology, University of Pretoria, Pretoria 0002, South Africa South Africa seems to escape the worldwide observed colony losses. Despite that all the major pests and diseases have been reported for South Africa, the honeybee population seems to be unaffected. Moreover, the outbreak in 2009 of American Foulbrood (AFB) does not have the expected negative effect on the South African population. The vital natural population with a high genetic diversity, thus buffering the negative effects of pests and diseases on the population, could play a role or alternatively, there is a lack of data. We have started a survey in order to fill this potential gap of knowledge and also to evaluate the impact of common honeybee diseases in the country. As expected all the major diseases are present, but it also shows a fundamental lack of identifying skills by the beekeepers. However, local pests, e.g. Capensis, are catching the attention of the industry. This suggests that the other pests and diseases are below the economical threshold, resulting in beekeepers ignoring them. If this conclusion holds, it also suggests that the natural population of African honeybees has traits and features successfully dealing with the diseases compared to its European counterparts. Therefore the African population is the ideal model for investigating the underlying mechanisms since and the overall population appears not to be diseased despite the presence of diseases. The carbon content of Portulacaria afra (L.) Jacq J.R. Pool a, B.S. Ripley a, M. Powell b a Department of Botany, Rhodes University, P.O. Box 94, Grahamstown 6140, South Africa b Department of Environmental Science, Rhodes University, P.O. Box 94, Grahamstown 6140, South Africa The demand for carbon credits, to offset carbon emissions, has resulted in the evolution of the carbon market where rights to carbon are bought as a method of offsetting carbon emissions. The Albany thicket biome of the Eastern Cape (South Africa) has been degraded by anthropogenic activities and its restoration has the potential to restore biodiversity, promote ecosystem services, provide sustained employment, and generate carbon credits which will have the potential to create a strong and lucrative South African based carbon economy. P. afra, commonly known as Spekboom, is a succulent facultative Crassulacean acid metabolism (CAM) plant from the family Portulacaceae. It is an endemic to the semi-arid Subtropical thicket. The exact carbon content of P. afra is yet to be scientifically verified. Because of its widespread adoption by restoration specialists and people with an interest in carbon credits and the South African carbon economy it is important to identify the exact carbon content of P. afra as a percentage of total biomass. Currently carbon stock calculations are based on the estimate that 48% of P. afra dry biomass is elemental carbon. Secondly, it is important to understand if and how carbon content varies with plant size. Allometric regression analyses found plant volume (cm 3) to be the best predictor of total plant above ground biomass. Exact carbon content (as a percentage of total dry biomass) results have far reaching implications. The allometric regressions reported in this study could aid in future biomass and carbon studies in subtropical thickets and may have SAAB Conference Abstracts value in rangeland condition assessments. Priority areas, in need of restoration, which will provide the most economic benefit (due to increased plant biomass accumulation) should be identified and restored preferentially. Long-term changes in the vegetation of Cape Point in response to climate and fire R.F. Powell a, M.T. Hoffman a, L. Gillson a, M. McGeoch b a Plant Conservation Unit, Botany Department, University of Cape Town, Private Bag X3, Rondebosch, Cape Town 7701, South Africa b Cape Research Centre, South African National Parks, Steenberg 7945, South Africa Climate change is a known threat to biodiversity worldwide and is predicted to have a major impact in the winter rainfall zone (WRZ) of South Africa. Projections show that temperatures are expected to increase and rainfall to decrease in the South Western Cape. The Cape of Good Hope Section of Table Mountain National Park (CGH) lies within this crucial area. This study investigates the drivers of change (climate, fire and land use) and the subsequent response of key vegetative growth forms to these changes in the conservation area. To understand past changes in CGH, climate data was analyzed over a 100 year period and fire frequency was investigated using Geographic Information Systems (GIS). Aerial photographs were compared and analyzed to get a further understanding of changes in land cover over a 63-year period. The response of key growth forms to these drivers was studied using repeat photography, with stratified points set out across the reserve. It was found that climate has not changed significantly over the time period, although mean annual maximum temperatures have increased (0.175 °C/decade). The frequency of fire in the reserve has also not changed significantly over the last 50 years. Comparison of the repeat photographs from 1966 showed that vegetation response varied across the reserve. In many cases there was very little difference in cover and growth form composition while in others significant changes in large proteoid shrubs (especially Protea lepidocarpodendron) were evident. Time since the last fire, alien plant clearing and local disturbance effects (e.g. mole rat (Bathyergus suillus) activity) appear to have an important impact on vegetation cover and composition. Although not evident over the recording period, climate change impacts on fire regimes and vegetation composition might be more evident over a longer time scale. Allelopathic effects of Amaranthus G. Prinsloo a , C.P. Du Plooy b a Department of Agriculture and Animal Health, University of South Africa (UNISA), Florida Campus, Private Bag X6, Florida 1710, South Africa 207 b Agricultural Research Council, Roodeplaat Vegetable and Ornamental Plant Institute (VOPI), Private Bag X293, Pretoria 0001, South Africa Amaranthus is highly valued by different communities in South Africa and it is preferred for its flavor and palatability by rural communities. It plays an important role in nutrition among the leafy vegetables grown worldwide. As these crops were growing as weeds, allelopathy has been known to exist for centuries as a way of survival mechanisms by plants. In a crop rotation or intercropping production system, Amaranthus may pose serious problems for the follow-up crop. The project consisted of three different trials to confirm and evaluate the extent of the allelopathic effects of Amaranthus on other crops. Each trial investigated a different aspect of the mechanisms of the possible allelopathic effect. A field trial, pot trial and seed germination trial were conducted to determine the allelopathic effects exhibited by Amaranthus. The field trial aimed at determining the effect of Amaranthus plants on four different vegetable crops namely spinach, tomato, cabbage and green peppers. The pot trial aimed at determining the allelopathic effects of three different Amaranthus species on tomato seedlings and the seed germination trial investigated the effects of a crude extract of Amaranthus and the effect of extracts from different plant organs on the seed germination of tomato, cabbage and two weeds namely Conyza bonariensis and Campuloclinium macrocephalum. All the extracts inhibited the seed germination of C. bonariensis, tomatoes and cabbage seeds. A high electrical conductivity (EC) value of the extract was an indication of a high concentration of ions which influenced seed germination and probably the inhibition of growth that were observed in the pot trials. The presence of a high concentration of oxalate in Amaranthus contributes to the effects observed as it is generally responsible for root inhibition of seed germination and protection of plants when accumulated in plant organs. An analysis of woody cover change in the mesic eastern region of South Africa using repeat photography J. Puttick a , M.T. Hoffman a, T. O'Connor b a Plant Conservation Unit, University of Cape Town, Rondebosch, 7701, South Africa b SAEON Grasslands-Wetlands-Forest Node, Ezemvelo KZN Wildlife, P.O. Box 13053, Pietermaritzburg 3202, South Africa Increases in woody cover in grasslands and savannas are a phenomenon observed worldwide over the last century and have social, economic, and conservation impacts due to associated losses in herbaceous productivity and biodiversity. Woody thickening is well documented in South Africa although most studies have been focused at local scales. We examined woody cover change over the last century for the mesic eastern region of South Africa using repeat photography. 200 Repeat photographs were spread over an altitudinal gradient from the coast to the Drakensberg, and a latitudinal gradient from the 208 SAAB Conference Abstracts Tugela Valley in the north to the Border region in the south. Woody cover change was quantified within landform units defined for each repeat photograph pair based on slope, aspect and catenal position. Woody cover increased within 64% of the landform units (n = 488), while 30% remained stable and 6% experienced a decrease in woody cover. Woody cover increases were greatest within the savanna, Albany thicket and Indian Ocean coastal belt biomes but also occurred within the grassland biome, particularly at the lower altitudes of the grassland range. Quantile regression of woody cover change versus altitude revealed a ceiling on woody cover increase, which declined with increasing altitude. Although a maximum ceiling on woody cover increase was apparent, observed woody cover change was highly variable (r 2 = 0.07) along the altitudinal gradient. We propose that the ceiling on woody cover increase is determined by global drivers such as climate and CO2 concentration while local land use drivers and abiotic factors such as soils and landform type contribute to the observed variability between sites. Anti-microbial and anti-inflammatory activities of Pleurostylia capensis Turcz. (Loes) [Celastraceae] M. Razwinani a, S.C.K.M. Motaung a, T.E. Tshikalange b, H.S. Abdillahi c, J. Van Staden c a Department of Biomedical Science, Tshwane University of Technology, Private Bag X680, Pretoria 0001, South Africa b Department of Plant Science, University of Pretoria, Pretoria 0002, South Africa c Research Centre for Plant Growth and Development, School of Life Sciences, University of KwaZulu-Natal Pietermaritzburg, Private Bag X01, Scottsville 3209, South Africa P. capensis Turcz. (Loes.) is a large tree that is used in traditional African medicine as a treatment of various diseases including epilepsy, mental illness and in combination with other plants for treatment of several ailments. It is also used to encourage sleep and bring good dreams. Extracts of three parts (roots, leaves and bark) of P. capensis (Celestraceae) were investigated scientifically for antimicrobial and antiinflammatory activities. Water, ethanol and dichloromethane (DCM) plant extracts were prepared and screened for antimicrobial activity using the micro dilution method against nine microorganism, namely S. aureus, E. coli, Klebsiella pneumonia, Klebsiella oxytoca, Streptococcus pyogenes, B. cereus, P. aeruginosa, S. typhimurium, M. smegmaris and C. albicans. Minimum inhibition concentration (MIC) and minimum bacteria concentration (MBC) of water, ethanol and DCM extracts were determined against these microorganisms. The antiinflammatory activity of water, ethanol and dichloromethane extracts were evaluated against both cyclooxygenase enzymes (COX-1 and COX-2). Out of three part plant extract, the roots and bark exhibited the MIC values ranging from 25.0 mg/ml to 1.563 mg/ml. The leaf extracts were not active especially against Gram-negative bacteria. This may be due to more chlorophyll being present. Gram-negative bacteria were found to be more resistant than Gram-positive bacteria. For antiinflammatory activity the ethanol and DCM extracts were the most potent. Ethanol (80%) barks and root extracts, gave the highest inhibitory activity against both COX-1 and COX-2. Inhibitory activity for COX-1 is 98.0% and 98.1% respectively. For COX-2, percentage inhibitions were 78.17% and 83.07% respectively. Water extracts, which are the most used solvents by traditional healers gave more than 50% inhibition against both COX-1 and COX-2. Photosynthetic and anatomical acclimation by the C3 and C4 subspecies of Alloteropsis semialata in low CO2 atmospheres B.S. Ripley a, R. Strauss a, C.P. Osborne b a Botany Department, Rhodes University, P.O. Box 94, Grahamstown 6140, South Africa b Department of Animal and Plant Sciences, University of Sheffield, Sheffield S10 2TN, UK The past 1–25 Myr have been characterized by sub-ambient partial pressures of atmospheric CO2 (Ca) which impose a greater limitation on C3 than C4 photosynthesis. In response to low CO2 it was hypothesized that C3 plants alter leaf anatomy and photosynthetic responses more than C4 plants in order to offset reductions in productivity. Here, we report the first phylogenetically controlled comparison of the effects of subambient Ca on leaf anatomy and photosynthetic responses of the C3 and C4 subspecies of A. semialata. Glacial CO2 concentrations resulted in marked alterations to C3 leaf anatomy that were associated with increased mesophyll conductance and even when combined with increased biochemical acclimation, was insufficient to maintain photosynthetic rates. In contrast, the C4 subspecies maintained photosynthetic rates and displayed less altered leaf anatomy. Our findings highlight the importance of biochemical and anatomical acclimations to atmospheric CO2 and add to the understanding of how historically low CO2 gave C4 plants a photosynthetic advantage. A molecular phylogeny of Encephalartos Lehm. P. Rousseau a,b, P. Vorster c, D.P. Little d, M. Van der Bank a,b a African Center for DNA Barcoding, University of Johannesburg, Department of Botany and Biotechnology, P.O. Box 524, Auckland Park 2006, South Africa b Department of Botany and Plant Biotechnology, University of Johannesburg, P.O. Box 524, Auckland Park 2006, Johannesburg, South Africa c Department Botany and Zoology, University of Stellenbosch, Private Bag X1, Matieland 7502, South Africa d Lewis B. and Dorothy Cullman Program for Molecular Systematics, The New York Botanical Garden, Bronx, New York 10458-5126, USA SAAB Conference Abstracts Encephalartos is an African endemic cycad genus of 65 species and 2 subspecies and is the most endangered group of cycads with 80% considered threatened (CR, EN, or VU) by the IUCN and all classed as CITES Appendix 1. Currently relationships within the genus, including species delimitation, are uncertain and in need of taxonomic investigation. Most studies to date have used a combination of more traditional lines of evidence such as morphology, anatomy and geography. Also no all-inclusive phylogenetic framework currently exists for Encephalartos. In the current study, DNA sequence from three plastid regions (rbcLa, psbA-trnH and matK) along with the nuclear region ITS was used to produce a phylogeny using multiple accessions per species where possible. Results show an increase in resolution at both the species and higher level and the delimitation of several new groupings. Each species grouping is characterized by shared derived morphological, ecological, and geographic characters. This study provides the first step toward a much-needed monograph of the entire genus. DNA barcoding of Africa's endemic cycads: Encephalartos Lehm. and Stangeria T. Moore P. Rousseau a,b, P. Vorster c, D.P. Little d, M. Van der Bank a,b a African Center for DNA Barcoding, University of Johannesburg, Department of Botany and Biotechnology, P.O. Box 524, Auckland Park 2006, South Africa b Department of Botany and Plant Biotechnology, University of Johannesburg, P.O. Box 524, Auckland Park 2006, Johannesburg, South Africa c Department Botany and Zoology, University of Stellenbosch, Private Bag X1, Matieland 7502, South Africa d Lewis B. and Dorothy Cullman Program for Molecular Systematics, The New York Botanical Garden, Bronx, New York 10458-5126, USA Africa's cycads (66 species and 2 subspecies in two endemic genera: Encephalartos and Stangeria) are extremely endangered with four species Extinct in the wild and 80% threatened (CR, EN, or VU) with all included in CITES Appendix 1. Although South Africa has some of the world's strictest cycad legislation, cycads are still under threat from illegal collection for horticulture and medicine especially where plants seized in an unidentifiable condition. Currently developed legislation demands accurate identification for permit issuing. Ex situ conservation of genetic and locality based diversity is paramount. Furthermore, taxonomically many species of unknown origin are difficult to identify especially when diagnostic characters are absent. Species delimitation and numbers are uncertain with field observations often contradicting current understanding. DNA barcoding can assist in all the above-mentioned scenarios and as such all proposed DNA barcoding regions (matK + rbcLa + psbA-trnH, nrITS) along with several additional regions were tested for all species encompassing ~350 samples. Results will focus on amplification success and discriminatory power of the different markers. 209 The rust pathogen Puccinia psidii, an eminent threat to South Africa J. Roux, M.J. Wingfield Department of Microbiology & Plant Pathology, Forestry and Agricultural Biotechnology Institute (FABI), University of Pretoria, Pretoria, South Africa Fungal pathogens represent one of the greatest threats to the survival of plants on earth, especially trees that live for long periods and adapt slowly. Several examples exist of the devastating impact that fungi have had on human existence via the destruction and contamination of food crops. The fact that trees suffer from diseases has only been recognized for about 130 years but there are many examples of fungal diseases changing entire ecosystems. The rust fungus P. psidii was first described in 1884 and has been described as the “biggest threat to the ecosystem” in Australia. It has a host range of more than 100 known hosts in the sub-family Myrtoideae. Until the 1970s P. psidii was known only from South and Central America and the Carribean Islands, but it has subsequently spread to the southern USA, Hawaii and Japan. Early in 2010 P. psidii was detected for the first time in Australia. In the 18 months since its first detection, it has spread throughout NSW and into Queensland, affecting various native Australian plants in the Myrtoideae. Current predictions, based on its impact on native Melaleuca species, are that it will eliminate several of these iconic tree species. The appearance of P. psidii in Australia should be of great concern to South Africa. Tests on South African Heteropyxis natalensis showed that this tree species is highly susceptible to this pathogen. South Africa has several tree genera in the Myrtaceae and the local forestry industry relies on susceptible Eucalypt species. We are, therefore, at risk of significant ecological and economic losses when this pathogen enters the country, as it undoubtedly will. This is particularly due to the ready exchange of people and products between these two countries. Significant effort should be placed on quarantine and breeding programmes to prepare for the appearance of P. psidii in South Africa and this should be done sooner rather than later. The ethnobotany, essential oil composition and antibacterial activity of southern African Teucrium species (Lamiaceae) A.K. Ruiters a, B.-E. Van Wyk a, S.F. Van Vuuren b, P.M. Tilney a a Department of Botany and Plant Biotechnology, University of Johannesburg, P.O. Box 524, Auckland Park 2006, Johannesburg, South Africa b Department of Pharmacy and Pharmacology, Faculty of Health Sciences, University of the Witwatersrand, 7 York Road, Parktown 2193, Johannesburg, South Africa Three southern African endemic species of the genus Teucrium, Teucrium africanum, Teucrium kraussii and Teucrium 210 SAAB Conference Abstracts trifidum of the family Lamiaceae are poorly studied with regard to their anatomy, essential oil composition and the scientific validation of their traditional medicinal uses as well as their taxonomic position in the genus. All three are used in traditional medicine to treat digestive and respiratory ailments. A summary of the published ethnobotanical information is presented. The essential oils were extracted from the three species, and water, methanol and dichloromethane: methanol extracts of the different plant parts made. These were used for the antimicrobial studies to determine the minimum inhibitory concentrations (MIC) against the bacteria, S. aureus, E. coli, B. cereus, K. pneumoniae, P. aeruginosa, Moraxella catarrhalis and S. pyogenes. The composition of the oils was also investigated with gas chromatography–mass spectroscopy (GC–MS). The essential oils of T. africanum and T. trifidum are very similar with αCubebene, β-Cubebene and β-Caryophyllene as main compounds. Antibacterial activity was recorded for T. africanum against E. coli, with an MIC value of 0.125 mg/ml (dichloromethane: methanol extract) and against S. pyogenes, with an MIC value of 0.16 mg/ml (essential oil). This data seems to at least partially validate the traditional uses of Teucrium species to treat digestive and respiratory ailments. Isolation and characterization of compounds from Calodendrum capense and Lydenburgia cassinoides with antimicrobial potential against opportunistic pathogens B.M. Sakong, A.S. Ahmed, L.J. McGaw, J.N. Eloff Phytomedicine Programme, Department of Paraclinical Sciences, University of Pretoria, Private Bag X04, Onderstepoort 0110, Pretoria, South Africa Infectious diseases are a serious concern worldwide especially in immune-compromised patients. The problem is compounded by the emergence of microbial resistant pathogens. A wide range of microbes including bacteria, fungi, parasites, viruses and protozoas are implicated as causative agents of various diseases. Two plant species (C. capense and L. cassinoides) used in South African traditional medicine for treating infectious diseases were screened for antimicrobial activities against C. albicans, C. neoformans, Aspergillus fumigatus, E. coli, P. aeruginosa, S. aureus and E. faecalis. L. cassinoides acetone extract generally had good activity, with MIC values ranging from 0.04-0.15 mg/ml while C. capense MIC values ranged from 0.31-0.62 mg/ml against the fungi. The two plant extracts had good antibacterial activity against S. aureus and P. aeruginosa, with MIC values ranging from 0.160.32 mg/ml. Antibacterial activity against E. coli and E. faecalis resulted in MIC = 0.63 mg/ml for both plants. Bioassayguided evaluation of the antimicrobial active components led to the isolation and characterization of lupeol from C. capense and ß-amyrin from L. cassinoides. The MIC of lupeol and ß-amyrin ranged from 1.5-6.2 μg/ml against all the tested organisms. Crude extracts and compounds were also tested for cytotoxicity against Vero (monkey kidney) cells. Both plant extracts had low toxicity with average IC50 values of 205.8 ± 8.38 μg/ml, for L. cassinoides crude extracts had 83.07 ± 44.66 μg/ml for C. capense crude extracts while IC50 values for the compounds were greater than 200 μg/ml, the highest concentration tested. This gave an excellent selectivity index of N 30 indicating the safety of the compounds. In conclusion both plant species showed broad antimicrobial activity against the standard strains of bacterial and laboratory isolates of fungal pathogens. The results validate the use of two plants as anti-infectious agents in traditional medicine. Immunomodulatory effect of Combretum molle leaves water extracts on the production and expression of cytokines and toll like receptors A. Samie, T. Nefefe, T. Mulaudzi, P.O. Bessong University of Venda, Department of Microbiology, Private Bag X5050, Thohoyandou 0950, South Africa Medicinal plants are known to have positive as well as negative effects on the immune system before and during infection. In the present study, peripheral blood mononuclear cells (PBMCs) were isolated from volunteers and maintained in culture in the presence of a stimulating agent (Phytohaemagglutinin: [PHA]) and the plant extracts. PBMCs isolated from HIV negative and HIV positive patients were tested. The effect of the plant extracts on the immune cells was assayed by measuring the production of interferon gamma in the cells supernatant in the first protocol and the measurement of mRNA production of several cytokines and Toll like receptors (TLRs) using a real time PCR procedure. Measurements of the effect of the extracts were conducted with and without activation by phytohemaglutinin. The measurement of INFγ in the cell supernatant indicated a slight increase in the production of the cytokine by cells that were exposed to the plant extracts following stimulation by PHA not before. There was a dose dependent variation of the effect of the extracts on the cytokine expression. PBMCs from HIV positive patients showed greater activation and higher production of INFγ compared to HIV negative patients. The mRNA expression of the cytokines and Toll like receptors was evaluated by real time PCR and showed high expression of IL6 by the cells. NFkappa B was also highly expressed by the cells as well as TLR2. The present study showed that C. mole has immunomodulatory capacities with special effect on improving the production of interferon gamma. The activation of the cells and consequently the improved expression of certain cytokines seem to use the NF kappa B pathway. Further studies are needed to identify the chemical constituents responsible for the observed effects. Species used by Bapedi Traditional Healers for the treatment of sexually transmitted diseases, Limpopo Province S.S. Semenya a, M.J. Potgieter a, L.J.C. Erasmus b SAAB Conference Abstracts a Departments of Biodiversity and bPhysiology and Environmental Health, School of Molecular and Life Sciences, University of Limpopo, Private Bag X1106, Sovenga 0727, South Africa Annually, millions of people are exposed to and affected by a variety of curable sexually transmitted diseases (STDs). These diseases can have a detrimental effect on the health status of the individual. This study found that 47 plant species from 44 genera belonging to 31 families are used to treat STDs, such as drop (gonorrhea), HIV/AIDS, khutlega, nta and tshofela (syphilis). Six of the 47 species are exotics, and were of significant value to traditional healers. The majority (87.5%, n = 41) of the species were used in the treatment of a single STD; only 12.5% (n = 6) were used in the treatment of more than one STD. Fifteen of the 47 species were used more than once for the preparation of an extract. The remaining 32 species all had a single application, thus was used to treat a single STD. A number of species used in the treatment of STDs are protected by National and Provincial legislation. These include, amongst others rare species such as Boscia albitrunca and Eleaodendron transvaalense (used to manage HIV infections), which are protected under the National Forest Act. Thirty five (76%) of these species appear in the Red Data List. These include Dioscorea sylvatica (vulnerable), Drimia elata (insufficient data), Eucomis pallidiflora (near threatened), and H. hemerocallidea (declining). These species, as noted by traditional healers are either declining or rare, and are increasingly being cultivated in home gardens. The large number of species employed in the treatment of STDs clearly reflects the diversity of treatment protocols used by Bapedi traditional healers. In the treatment of the more prominent STDs a number of alternative species can be used, which in itself will ensure that treatment options are always available. In vitro germination of the threatened assegai tree, Curtisia dentata S. Shaik School of Biological and Conservation Sciences, University of KwaZulu-Natal, Westville Campus, Private Bag X54001, Durban 4000, South Africa C. dentata (Cornaceae) is a medicinally important indigenous tree native to southern Africa. In South Africa the stem bark of this threatened species has been overharvested to treat many medical conditions in humans and animals. As a result of its threatened and protected status this study was performed to investigate whether in vitro germination of C. dentata seeds could be utilized as a possible mechanism to conserve the species. In the wild, propagation of C. dentata through seed may be difficult and could take many weeks provided the climate and rainfall are favorable. Seed yields can also fluctuate on a year to year basis and current diminishing populations can exacerbate seed shortage. In addition, beetle predation of seeds 211 is a current and real problem. If seeds do survive to seedling stage they become vulnerable to damage from drought, high surface soil temperature, frost and damping off fungi. Therefore, the alternative cultivation and conservation techniques of in vitro germination were considered. Experiments using physical, mechanical and chemical pre-sowing treatments were conducted in light and dark conditions to determine the germination response of this species. Among the various treatments, the highest germination percentage was achieved in seeds treated with concentrated H2SO4 for 10 min and incubated in the light. The quickest germination response was obtained in mechanically scarified treatments on day 3 in both light and dark conditions. The results indicate that C. dentata seeds possess exogenous dormancy due to the thick tough seed coat which is the main inhibitor of germination. Evaluation of antibacterial, antioxidant and mechanistic activities of a plant from Myrtaceae family addressing acne vulgaris R. Sharma, A. Hussein, N. Lall Department of Plant Science, University of Pretoria, Pretoria 0002, South Africa Fifty plant species grown in South Africa were selected for their antibacterial activity. Ethanol extracts were prepared and tested for their action on Propionibacterium acnes and the Minimum Inhibitory Concentration (MIC) were evaluated. The results using the broth dilution methods showed that many crude extracts could inhibit the growth of P. acnes. The leaf extract of a plant from a family Myrtaceae exhibited best MIC value of ≤ 62.5 μg/ml. The cytotoxicity effects of this extract were determined by colorimetric XTT {2,3-bis (2-methoxy-4nitro-5-sulfophenyl)-5-[(phenylamino) carbonyl]-2H-tetrazolium hydroxide} assays on human macrophages U937 cells. The extract showed low cytotoxicity exhibiting a 50% inhibitory concentration (IC50) of 400 μg/ml. Phytochemical test revealed the presence of phenols, tannins, anthraquinones and flavonoids in the ethanol extract. Bioassay-guided isolation of ethanolic extract led to the isolation of two compounds. The first compound (triterpene) did not show activity against P. acnes at the highest concentration (500 μg/ml) tested; whereas the second (6-alkyl salicylic acid) compound exhibited MIC of 0.25 μg/ml. The extract was further investigated for its inhibitory activity on glutathione disulfide reductase and mycothiol disulfide reductase enzymes at concentrations ranging from 800 μg/ml to 1.56 μg/ml. The IC50 was found to be between 6.25 and 3.125 μg/ml for glutathione disulfide reductase and 36.77 μg/ml for mycothiol disulfide reductase. The antioxidant activity was detected by DPPH (2,2-diphenyl-1-picrylhydrazyl) radical scavenging capacity and EC50 (substrate concentration to produce 50% reduction) was found to be 0.89 μg/ml. The antibacterial activity of potent samples was further confirmed by means of Transmission Electron Microscopy. 212 SAAB Conference Abstracts Characterization of phenolic compounds in aqueous extracts from seed coats of marama bean (Tylosema esculentum) J.S. Shelembe a, D. Cromarty b, M.J. Bester c, A. Minnaar a, K.G. Duodu a a Department of Food Science, bDepartment of Pharmacology, c Department of Anatomy, University of Pretoria, Pretoria 0002, South Africa The marama bean is an underutilized legume growing wild in the arid and semi-arid regions of southern Africa. The seed coats of marama beans contain antioxidant phenolic compounds with potential health benefits, but are not consumed. Aqueous extracts for use as antioxidant functional food ingredient from seed coats of marama beans were prepared by extracting with water (water extract) or with water acidified to pH 2 (acidified water extract). The extracts were analyzed for phenolic content using spectrophotometric methods. Phenolic acids, flavonoids and proanthocyanidins were analyzed by HPLCMS. Free radical scavenging activities of the extracts and their protective effect against free radical induced human erythrocytes hemolysis, oxidative DNA damage and human LDL oxidation were determined. Extraction of marama bean seed coats under acidic conditions resulted in reduction in phenolic compound content, antioxidant activity and lower protective effect against erythrocyte hemolysis with no significant differences in their protective effect against oxidative DNA damage and LDL oxidation. Gallic acid and methyl (epi)afzelechin-3O-gallate were the major phenolic acid and flavonoid compounds respectively in the marama bean seed coat aqueous extracts. Proanthocyanidins were predominantly highly galloylated prodelphinidins. The findings of this study show that the extracts have a potential to reduce oxidative stress which is implicated in many chronic diseases such as neurodegenerative diseases, cancer and cardiovascular disease. Evaluation of the mutagenicity and stability of plant extracts with potential use in the cosmetic field from the Myrsinaceae family S. Singh, N. Lall Department of Plant Science, University of Pretoria, Pretoria 0002, South Africa The leaves and stems of a plant from the Myrsinaceae family, which is indigenous to southern Africa, have shown substantial anti-tyrosinase activity. The 10% propylene glycol plant extract, as well as its formulation, was tested under different temperatures in order to determine their stability at Stability Testing Services. The storage period extended over 3 months. The pH, specific gravity, appearance, odor and viscosity were tested at these intervals. Analysis of the results revealed that the sample stored at 25 °C was most stable as it retained most of the original activity. Approximately 90% of tyrosinase inhibition was observed when the sample was tested at 1%. The physio-chemical properties such as pH, refractive index, relative density, appearance and odor were determined. In order to determine the mutagenicity of the extract, samples of the extract were tested on strains of Salmonella typhimurium (S. typhimurium) in accordance with the Ames test. The number of revertant colonies observed for the T98 and T100 strains at the highest concentration (5 mg/ml) was 18.67 ± 1.15 and 103.33 ± 2.52 respectively. The number of revertant colonies in the blank plates was observed to be 112.40 ± 3.65. According to the Ames test, a sample must have more than twice the number of revertant colonies produced in the blank plates in order to be mutagenic. The extract was classified as non-mutagenic according to these tests. The irritancy and the skindepigmentation properties of the extract were tested at Future Cosmetics. The irritancy potential of the extract was calculated to be − 9.00% and overall the extract was observed to be a nonirritant by Future Cosmetics CC. This plant can be beneficial in the treatment of hyper-pigmentation, a common skin disorder. Dealing with newly detected invader: Sagittaria platyphylla H.J.N. Sithole Early Detection and Rapid Response Programme (EDRR – funded by Working for Water) South African National Biodiversity Institute, P.O. Box 52099, Berea Road, Durban 4007, South Africa The Early Detection and Rapid Response to emerging invasive alien plants programme (EDRR) aim to reduce the incidence of plant invasions through identifying them at an early stage of invasion, plan rapid responses, explore and recommend effective control methods. S. platyphylla is one of the newly detected invaders from Tropical America. It has severe ecological impacts and poses a great threat to wetlands in South Africa. The coastal areas are under a high threat because the climatic conditions resemble that of the country of origin. S. platyphylla is not yet declared as an invader in South African legislative context therefore there are no recommended methods to control it, but the process to get it declared has been initiated. In the meantime EDRR has performed several activities and explored possible control methods. Achieved tasks are highlighted: species identity has been verified, awareness raising, mapping and herbicide field trials are in progress. Thus the talk serves to encourage the like minded to support EDRR Programme with sightings and provide inputs. High throughput expression analysis of miRNAs and their targets involved in the water deficit response in Vitis vinifera M.C. Solofoharivelo a, A. Van der Walt b⁎, J. McBride b, D. Stephan a, M.J Freeborough a, J.T. Burger a, S. Murray b a Vitis Lab, Department of Genetics, Stellenbosch University, Private Bag XI, Matieland 7602, South Africa SAAB Conference Abstracts b Centre for Proteomic and Genomic Research, P.O. Box 81, Observatory 7935, Cape Town, South Africa *Current address: Central Analytical Facility, Stellenbosch University, Private Bag X1, Matieland 7602, South Africa MicroRNAs (miRNAs) are small non-coding RNAs that regulate diverse biological processes across various organisms. In plants, miRNAs have been associated with plant development and in the response to biotic and abiotic stress. In this study, we investigated the role of miRNAs in V. vinifera (grapevine) under mild to severe water deficit. Grapevine is one of the most important fruit crops in the world. Abiotic stress caused by water deficit can severely limit plant development, growth and yield. Although grapevine has been described as moderately tolerant to drought, recent evidence has shown that gene expression is modulated by low to severe water deficit. Here, using miRNA microarray technology to analyze miRNA expression during drought treatment of grapevine plants, we identified several miRNAs that were differentially expressed. Putative targets of these miRNAs were also identified using a whole genome Vitis microarray. Both miRNAs and miRNA targets were validated by quantitative real-time qPCR. Several of these miRNAs have been implicated in drought responses in other plant species. The chemical composition, antimicrobial and antioxidant properties of the essential oils of Tulbaghia violacea and Eucalyptus grandis O.S. Soyingbe a, A.O. Oyedeji b, M. Singh c , A.R. Opoku a a Department of Biochemistry and Microbiology, University of Zululand, Private Bag X1001, KwaDlangezwa 3886, South Africa b Department of Chemistry, Walter Sisulu University, Private Bag X1, Mthatha 5117, South Africa c Department of Biochemistry, University of Kwazulu-Natal (Westville Campus), Durban 4000, South Africa T. violacea (Harv.) L.f. and E. grandis W.Hill ex Maiden are medicinal plants used by Zulu traditional healers to treat respiratory track diseases. Essential oils hydrodistilled from the rhizomes of T. violacea and the leaves of E. grandis were evaluated for the chemical composition, antioxidant and antibacterial activities. The GC and GC-MS analyses of the oils revealed the main constituents of the essential oils of T. violacea, to be 2,4-Dithiapentane (51.04%), p-Xylene (20.59%), Chloromethylmethyl sulfide (8.69%), o-Xylene (7.38%), Thiodiglycol (6.43%), and p-Xylol (5.88%). The main constituents of the essential oils of E. grandis are mXylene (49.25%), Ethylbenzene (16.86%), Eucalyptol (15.50%), o-Xylene (14.24%) and Limonene (5.14%). While the oils of T. violacea showed weak antioxidant activity, the essential oils of E. grandis, exhibited a high DPPH and ABTS scavenging activity. The antimicrobial activity of the essential oils showed that the oils of T. violacea were 213 affective against 8 of the 16 microorganisms tested with MIC values ranging from 2.5 μg/ml to 5.0 μg/ml; the oils of E. grandis were active against 13 of the 16 organisms tested with the MIC ranging from 0.625 μg/ml to 5.0 μg/ml, and the MBC values ranging from 2.5 μg/ml to 10 μg/ml. The essential oils of E. grandis were also tested against 8 antibiotic resistant bacteria, and were seen to show activity against 7 of the 8 with MIC ranging from 5 μg/ml to 10 μg/ml. The Oils had low (1218 μg/ml, and 1641 μg/ml) cytotoxicity levels against HEK293 and HepG2 cell lines respectively. It is apparent that the bioactivity of the essential oils of T. violacea and E. grandis contribute to the use of these plants in folk medicine. A phytochemical and morphological comparison between Pachystigma macrocalyx, Pachystigma pygmaeum and Pachystigma thamnus S.L. Stanton a, C.F. Van der Merwe b, A. Hussein a, S.N. Venter c, T.A. Coutinho c , J.J.M. Meyer a a Department of Plant Science, University of Pretoria, Pretoria 0002, South Africa b Laboratory for Microscopy and Microanalysis, University of Pretoria, Pretoria 0002, South Africa c Department of Microbiology and Plant Pathology, University of Pretoria, Pretoria 0002, South Africa ★ Best oral presented by MSc student The plants of the Rubiaceae family, specifically P. macrocalyx, P. pygmaeum and P. thamnus have been the focus of very little research. P. pygmaeum and P. thamnus have been assumed to contain the polyamine pavettamine and thus cause the disease “Gousiekte” in domestic ruminants; however extensive studies have not been done on P. macrocalyx. The aim of this study was to compare these plants on morphological and phytochemical aspects. The bacterial endophytes, which may cause the toxicity, were compared using electron microscopy and isolation techniques. The chemical compositions of the three plants were analyzed using TLC, NMR and metabolomic procedures. In the TLC analysis the standard, pavettamine was spotted along with the crude extracts of the three plants; the TLC plates were run on both polar and non-polar mobile phases to reveal the compound composition. The compounds which reacted with ninhydrin, possible polyamines, were noted and also analyzed by NMR to determine their chemical structures. Twenty samples of each species were used for the metabolomic study to determine the differences between different collection sites and the individual plants within the sites. These toxic compounds will be subjected to toxicity tests along with compounds isolated from the endophytes in future. Due to the hypothesis that extracts from P. pygmaeum and P. thamnus are responsible for the degradation of the ruminant's myofibers, H9c2 cells which are derived from embryonic rat cardiac cells, will be used to determine toxicity. 214 SAAB Conference Abstracts Breeding systems in Protea S-L. Steenhuisen, S.D. Johnson School of Life Sciences, University of KwaZulu-Natal Pietermaritzburg, Private Bag X01, Scottsville 3209, South Africa It has been assumed that species of the large African genus Protea have strong self-incompatibility systems. However, this assumption was based largely on studies conducted on a clade of bird-pollinated species that occur in the shrubby fynbos vegetation of the Cape region of southern Africa. To test whether self-incompatibility occurs in a grassland/savanna Protea clade, which is largely insect-pollinated, we performed controlled pollination experiments on four species – Protea caffra, Protea simplex, Protea dracomontana and Protea welwitschii. Although pollen-ovule ratios of all four species fall within the range for outcrossers, all four species are self-compatible and capable of autogamous seed production. In P. caffra, a small tree expected to carry substantial genetic load, selfed progeny had rates of germination and early seedling survivorship which were identical to those of crossed progeny. Selective exclusion experiments and allozyme analysis of eight polymorphic loci in progeny revealed that exclusion of vertebrate visitors to P. caffra did not reduce outcrossing rates, and we could infer that insects are effective agents of crosspollination in P. caffra. However, high inbreeding depression (δ = 1) and a marked difference between maternal and progeny Wright's fixation indices suggest that selfed progeny may not reach reproductive maturity. The grassland Protea species studied are visited intensively by insects and are thus likely to be facultatively autogamous with mixed mating systems. If one assumes previous reports of self-incompatibility in Protea to be reliable, there have been at least five losses of SI and two gains of autonomous self-pollination in this genus. However, earlier studies in the genus were often methodologically flawed and a thorough re-analysis of breeding systems in Protea is required. Woody cover change in the north-east arid savannas of South Africa from 1940–present N. Stevens a,c, B.F.N. Erasmus b, S. Archibald c, W.J. Bond a a Botany Department, University of Cape Town, Private Bag, Rondebosch 7701, South Africa b School of Animal, Plant and Environmental Sciences, University of the Witwatersrand, WITS 2050, South Africa c Natural Resources and the Environment, CSIR, P.O. Box 395, Pretoria 0001, South Africa Increasing tree cover in “open” systems is occurring globally. Tree cover increases in arid savanna regions of South Africa have been noted to be extensive and widespread. Numerous theories have been proposed as to what is determining increases in these dry (b 450 mm) savannas. Local land-use management actions or global drivers particularly elevated CO2 have been considered to be the primary drivers, however some authors suggest that the perceived changes are part of the inherent variability of the system. This debate remains unresolved as very few multi-site, multi land-use, large-scale evaluations of woody plant encroachment exist, with the majority of the studies documenting woody encroachment in an area less than 10 km 2. We measured the magnitude of woody cover change in the north-east arid savannas of South Africa across a 160 km 2 area consisting of three distinctly different land-use types; communal rangelands, commercial rangelands, conservation areas with elephants. Tree cover change was measured between 1940 and 2009 using the aerial photo record. Detection of woody cover from each aerial photograph was automated using ECognitions' Object Based Image Analysis (OBIA). Tree cover increased in commercial and communal areas and decreased in conservation areas with elephants, however tree cover changes were approximately 10% and therefore unlikely to be a significant alteration to the landscape. The overall composition of the canopy structure however has shifted toward smaller canopied plants. Our study indicates that overall land cover has remained constant but there may be a shift in the woody structure of these systems. The effect of cold stress on infection of Cavendish bananas with Fusarium oxysporum f. sp. cubense R. Sutherland a, A.M. Viljoen b, A.A. Myburg c, N. Van den Berg c a Department of Microbiology and Plant Pathology, Forestry and Agricultural Biotechnology Institute (FABI), University of Pretoria, Pretoria 0002, South Africa b Department of Plant Pathology, University of Stellenbosch, Private Bag X1, Matieland 7600, South Africa c Department of Genetics, FABI, University of Pretoria, Pretoria 0002, South Africa The soil-borne fungus F. oxysporum f. sp. cubense (Foc) causes Fusarium wilt of banana, one of the most destructive plant diseases known. Some strains of the fungus, designated Foc sub-tropical race 4 (STR4), cause disease to Cavendish bananas in cooler regions of the world, particularly after winter. The aim of this study was to determine why Cavendish banana plants become susceptible to Foc STR4 following predisposition by cold temperatures. Cavendish banana plantlets were subjected to three different treatments: (a) inoculation with Foc STR4 at 25 °C, (b) incubation at of 10 °C for 2 weeks followed by inoculation with Foc STR4 at 25 °C, and (c) inoculation with Foc STR4 at 10 °C. RNA was extracted from banana roots at 3 and 12 h post inoculation and cDNA generated. cDNA libraries were constructed and sequenced on a 454 GS FLX pyrosequencer (15464 reads, 3.9 Mbp). An average of 417 contigs per library with an average contig length of 615 bp was obtained with 55.64% of the transcripts showed similarity to the rice genome. The putative functions of transcripts were determined by homology searches on the National SAAB Conference Abstracts Center for Biotechnology Information (NCBI) database. Genes identified include PR1, peroxidase, abscisic stress ripening protein and phenylalanine ammonia lyase. Gene expression analysis is currently underway to better understand the roles of these in defense and cold stress at different time intervals. Preliminary results suggest down-regulation of defense genes during cold stress. By reducing cold stress during the winter months, or by uncoupling cold stress from down-regulation of defense genes, Foc STR4 may be controlled in sub-tropical countries. Fragrances and flavors of some South African plants K.M. Swanepoel a, P. Soundy b, W.G. Alberts c a Southern African Essential Oil Producers Association (SAEOPA), P.O. Box 462, Newlands, Pretoria 0049, South Africa b Department of Soil Science, University of Pretoria, Pretoria 0002, South Africa c KARWIL Consultancy, Coral str 111, Lynnwood Glen, Pretoria 0082, South Africa According to the fragrance and flavor industry, there is a constant need for new flavors and aromas in the world. Latest trends show an interest in South African plants with known and unknown fragrances and flavors. Few indigenous plants have been investigated for potential in the perfumery and flavoring industry. South Africa with its variety of flora, has untapped potential in the flavor and fragrance industries. Many rural areas rich in bio diversity are also poverty stricken and will need opportunities for development e.g. natural products in the fragrance and flavor industries. Some of the aromatic plants were identified with potential of commercial production for the fragrance and flavor industry. The indigenous plants that have been investigated for potential further production include: Mondia whitei, Athrixia phylicoides, Warburgia salutaris, Siphonochilus aethiophicus, O. lanceolata, Cymbopogon validus, Spirostachys africana, Tarchonanthus camphoratus, H. odoratissimum, Acacia nilotica, Croton gratissimus, H. natalensis, L. javanica and Dovyalis caffra. Pelargonium spp., Agathosma spp. (Buchu) and S. birrea (Marula) and are already well known for valuable and distinctive properties in the flavor and fragrant applications. There are many more species in South Africa that should be researched for the unique South African flavor and fragrance properties. Sensory evaluations were done by the flavor and fragrance industry and chemical analysis need to be completed, before the agricultural potential could be investigated and explored for selection as future crops. DNA fingerprinting of Acacia karroo: Attempting to resolve taxonomic uncertainties and inform ecological observations C.L. Taylor, N.P. Barker Department of Botany, Rhodes University, P.O. Box 94, Grahamstown 6140, South Africa 215 A. karroo Hayne is a very common woody species in South Africa. The species displays a large amount of variation, especially in terms of its morphology with enormous variation in the architecture of fully grown trees. Genetic variability of the species throughout South Africa was examined to test whether it is correlated to the different morphotypes or ecotypes. The species is also currently encroaching in some areas of its distribution and it is hypothesized that one ecotype/genotype is responsible for this encroachment. These findings could inform management practices in the encroached areas. The study uses Inter-Simple Sequence Repeat (ISSR) fingerprinting method to investigate the genetic diversity in this species. Additionally DNA extracts from fresh and silica dried samples of the same plant were tested to determine whether the treatment of silica drying compromises DNA extract and thus the quality of the Inter-Simple Sequence Repeat Polymerase Chain Reaction. The ISSR analysis found no specific genotypes within A. karroo. No difference was found in the quality of DNA extracted from fresh compared to dried specimens. Acacia saligna invasions: Genetics and species distribution modeling G.D. Thompson a , D.U. Bellstedt b, J.J. Le Roux a, D.M. Richardson a, J.R. Wilson a,c a Centre for Invasion Biology, Department of Botany and Zoology, Stellenbosch University, Matieland 7602, South Africa b Department of Biochemistry, Stellenbosch University, Matieland 7602, South Africa c South African National Biodiversity Institute, Kirstenbosch National Botanical Gardens, Claremont 7735, South Africa ★ Best oral presented by PhD student A. saligna, a species complex native to Western Australia, is highly invasive in 20 countries on four continents. Using genetic analyses, we determined which lineages of the species complex (putative subspecies) are represented in the invasive range in South Africa. In addition, we used species distribution models to explore whether high genetic structure influenced native and introduced distribution patterns. From population genetic (microsatellites) and phylogenetic (nDNA and cpDNA) analyses, we found deep phylogenetic divergences between the native and introduced South African populations, such that we were unable to associate South African entities with any native subspecies of A. saligna. We then assessed distribution patterns by constructing correlative species distribution models for the different subspecies of A. saligna. These models accurately distinguished between the native subspecies niches, but were unable to accurately predict introduced distributions in South Africa and the Mediterranean Basin. Both the ecological and genetic findings suggest that a novel genetic entity of A. saligna is present in South Africa. We speculate that this novel entity may have arisen due to cultivation practices in Western Australia, and that this was the entity that was introduced to South Africa. As a consequence, the invasive 216 SAAB Conference Abstracts populations of A. saligna may have no historical analog in the native range (genetically or in terms of a realized climatic niche). This highlights the need to consider that native and invasive plant populations are distinct entities (genetically or in terms of realized climatic niche) which is in contrast to current assumptions that such populations are one and the same. Do leaves play a more active role in the symbiotic relationship between domatia and mites? P.M. Tilney a, A.E. Van Wyk b, C.F. Van der Merwe c a Department of Botany and Plant Biotechnology, University of Johannesburg, P.O. Box 524, Auckland Park 0006, South Africa b Department of Plant Science, University of Pretoria, Pretoria 0002, South Africa c Laboratory for Microscopy and Microanalysis, University of Pretoria, Pretoria 0002, South Africa Domatia are small structures on the lower surface of a leaf, usually consisting of cavities or pouches covered by hairs or leaf tissue, located in the axils between the midrib and secondary veins. They are found in many dicotyledons including certain members of the Rubiaceae. In the tribe Vanguerieae of this family, they may or may not be present. As part of an ongoing study of selected southern African members of the Vanguerieae, their structure in transverse section was investigated. Light microscopic (LM) observations revealed the presence of a number of “channels” extending from the outer periclinal cell walls of the epidermal cells across the cuticle toward the cavity of the domatia in some of the taxa. These structures in Plectroniella armata were also examined using transmission electron microscopy (TEM). Domatia are known to house mainly mites, many of which are predatory or fungivorous, in a symbiotic (mutualistic) relationship. To date, the role of domatia is thought to be confined to the provision of shelter for these organisms, their eggs and their young during development. However, the present study of the microscopic structure of domatia revealed not only that the cuticle of the epidermis of the domatia is thicker than in other parts of the leaf, but also the presence of pronounced and closely-spaced cuticular folds which are particularly conspicuous in domatia. What appear as transcuticular “channels” under LM turned out to be cuticular folds with electron dense inclusions under TEM. The functional significance of the folds requires further investigation. In plants such folding of walls and membranes at ultrastructural level is usually functionally associated with an increase in surface area to facilitate the active exchange of compounds/metabolites. This may indicate that translocation of substances is possible from the domatium to the inhabitants (or vice versa) and therefore suggests a far more active role for the leaf in the symbiotic relationship than was previously thought. More work is required to test such a possibility. The CREW Programme: Making significant contributions to taxonomy and conservation M. Treurnicht, I. Ebrahim South African National Biodiversity Institute, Kirstenbosch Research Centre, Private Bag X7, Claremont 7735, South Africa The Custodians of Rare and Endangered Wildflowers (CREW) is a programme that involves civil society in monitoring and conserving threatened plants. Our CREW volunteers have been providing us with critical data required for updating Red List Assessments, contributing to identifying conservation priority areas, making significant new plant discoveries and submitting important distribution records and specimens to several South African herbaria. The focus of this paper is to illustrate the important contributions that citizen scientists make to Botany by showcasing their new discoveries, collaborative projects with taxonomists and building on valuable herbarium collections. Since the inception of the CREW programme in 2003 we have discovered 15 new species, rediscovered 13 species and collected population data on 825 species of conservation concern. Some Cape Erica species can self-pollinate: evidence for autogamy and geitonogamy, with a facultative and out-crossing seed-set advantage, in Erica chloroloma (Ericaceae) R.C. Turner a, J.J. Midgley b, S.D. Johnson a a School of Life Sciences, University of KwaZulu-Natal Pietermaritzburg, Private Bag X01, Scottsville 3209, South Africa b Department of Botany, University of Cape Town, Rondebosch 7701, South Africa High levels of observed fruit-set in wild populations of E. chloroloma, Cape St. Francis, South Africa, led us to hypothesize that, despite frequent visitation by Malachite Sunbirds and Greater Double Collared Sunbirds, a certain amount of self-fertilization was occurring. We employed breeding experiments to determine the relative amounts of seed-set in terms of autogamous, geitonogamous and allogamous pollination. Our results indicate highest seed set with outcrossing but that autogamous and geitonogamous fertilization can contribute significantly towards seed-set. Furthermore, facultative autogamy yielded higher seed-set than unmanipulated autogamy. We also determined that insects, mostly Apis mellifera capensis bees, were responsible for up to 20% of seed-set through selfing but not necessarily pollen transfer. Observed floral robbery by Cape Weavers and White Eyes also contributes towards seed-set through facultative disturbance of anther rings and subsequent selfing. As a result of these factors, high fertilization levels are achieved and the species thus has a negligible pollen limitation value of 0.005 by the Larsen-Barrett index. Despite protogyny, the stigmas of individual flowers are receptive to their own pollen as soon as the stigma emerges from the SAAB Conference Abstracts corolla mouth. Our results showing that E. chloroloma has hedged its reproductive bets through the ability to selfpollinate, and that it is thus likely, despite relatively large sub-populations and abundant pollinators, that genetic diversity within stands of the species is lower than in similar-sized populations of allogamous, bird-pollinated Cape Erica species. Climate change-driven mortality of Euphorbia ingens in the Limpopo Province: Causal abiotic and biotic factors J.A. Van der Linde a, D.L. Six b, M.J. Wingfield a, J. Roux a a Department of Microbiology and Plant Pathology, DST/NRF Centre of Excellence in Tree Health Biotechnology (CTHB), Forestry and Agricultural Biotechnology Institute (FABI), University of Pretoria, Private Bag X20, Hatfield 0028, Pretoria, South Africa b College of Forestry and Conservation, Department of Ecosystem and Conservation Sciences, The University of Montana, Missoula MT 59812, USA The plant genus Euphorbia is one of the most diverse in the world including more than 2100 species of both succulent and woody plants. In South Africa, the largest of the succulent tree-like euphorbias is E. ingens. In the last 10 to 15 years, high levels of mortality of these trees have been observed in the Limpopo Province of South Africa. The main symptoms include rotting and browning of the succulent branches, gray discoloration of the foliar parts, various spots and lesions on succulent branches, blue stain of the main woody stems as well as insect damage. In the past five years, a number of studies have been undertaken to investigate the possible causes of disease and mortality in this tree, looking at both biotic (fungal and insect) and abiotic (temperature, rainfall, evapotranspiration) factors. Diseased plant material and associated insects were collected from four sites in the Limpopo Province. Fungi were isolated from insect tunnels in the succulent branches, blue stained wood as well as from insects collected from diseased plant material. Insects included weevils (Scolytinae), bark beetles (Cossoninae) and a moth (Pyralidae). A wide diversity of fungi were isolated belonging to the Botryosphaeriaceae, Cordycipitaceae, Microascales, Nectriaceae, Ophiostomataceae and the Teratosphaeriaceae. Analyses of weather data revealed changes in annual temperature and precipitation over the 40 year period analyzed, with greater upward trends in temperature and downward trends in precipitation in the Limpopo Province compared with the North West Province. Estimates of potential evapotranspiration and water balance indicated an increasing water demand while precipitation has remained the same or is decreasing. The dramatic death of E. ingens observed, since about 2000, appears to be linked to increasing moisture deficits resulting in tree stress. This in turn results in increased damage by opportunistic pathogens and insects ultimately contributing to tree mortality. 217 Pollinator ecotypes in the shrub Erica plukenetii T. Van der Niet, R. Turner, J.J. Midgley Botany Department, University of Cape Town, University Private Bag, Rondebosch 7700, South Africa Pollinator-driven speciation has been proposed as an important factor driving speciation in the mega-diverse Cape Floristic Region. Most evidence in favor of this hypothesis put forward to date has come from large geophytic irid and orchid lineages, while data from proteoid and legume lineages seem to suggest that pollinators were not important. Here we present a case of pollinator ecotypes, arguably a key element in demonstrating pollinator-driven speciation, for Erica, the largest genus of the Cape flora. The widespread E. plukenetii is characterized by great variation in vegetative and floral traits. The most common form, with long-tubed red flowers, was visited by orangebreasted sunbirds that carried large amounts of Erica pollen at the base of their beaks. Beak length closely matched the length of the floral tube, and flowers were unscented, as is typical of bird-pollinated flowers. Another form was characterized by white, short-tubed flowers which emit a pleasant floral scent. We speculate that this form is visited by nocturnal moths. The two forms have been found to co-occur in nature, reinforcing their status as genuine pollinator ecotypes. This is the first evidence for a role for pollinators in driving diversification in the florally diverse heaths, which constitute almost 10% of the entire Cape flora, and it refutes the idea that this process is limited to geophytic herbs only. Biodiversity and restoration of Spekboom-dominated thicket M.L. Van der Vyver a, R.M. Cowling a, A.J. Mills b, M. Difford a, E.E. Campbell a a Restoration Research Group, Department of Botany, P.O. Box 77000, Nelson Mandela Metropolitan University, Port Elizabeth 6031, South Africa b Restoration Research Group, Department of Soil Science, Stellenbosch University, Private Bag X1, Matieland 7602, South Africa An accepted criterion for measuring the success of ecosystem restoration is the return of biodiversity relative to intact reference ecosystems. The emerging global carbon economy has made landscape-scale restoration of severely degraded P. afra (Spekboom)-dominated subtropical thicket, by planting multiple rows of Spekboom truncheons, a viable land-use option. Although large amounts of carbon are sequestered when planting a monoculture of Spekboom, it is unknown whether this is associated with the return of other thicket biodiversity components. We planted in degraded, intact and three differently aged post-restoration (P. afra truncheons) sites nurserypropagated individuals of two woody canopy dominants (Pappea capensis and Searsia longispina), and two intercanopy shrubs (Lycium ferocissimum and Rhigozum obovatum) 218 SAAB Conference Abstracts in September 2008 (spring). The experiment was repeated again in May 2009 (autumn) and a succulent canopy species (P. afra) was added. We assessed restoration success in terms of the survival of planted individuals after 24 months (spring planting) and 12 months (autumn planting). Contrary to expectations, survival was not related to a gradient of intactness encompassing degraded, restoration and intact treatments that are associated with increasing biomass and soil carbon. The costs of incorporating the four woody canopy species into the restoration programme's protocol were 2.4 times the costs of restoring with P. afra alone. We also used carbon stock data from restored and intact sites, and sampled carbon stocks at restored stands at a second site in the same thicket plant community. Similarly, we sampled plant community composition at both sites. The total carbon stock of the oldest post-restoration stand (250.8 ± 14 t C ha - 1) approximated that of intact stands (245 t C ha - 1) and we observed a general increase in carbon content with restoration age (71.4 ± 24 t C ha - 1 after 35 and 167.9 ± 20 t C ha - 1 after 50 years). A multiple correspondence analysis separated degraded stands from stands under restoration based on ground cover, floristic composition and total carbon stock. Older post-restoration and intact stands were clustered according to woody canopy recruit abundance. Our results suggest that Spekboom is an ecosystem engineer that promotes the spontaneous return of canopy species and other components of thicket biodiversity. Identifying genomic regions involved in growth, wood property, transcript and metabolite variation in an F2 pseudo-backcross pedigree of Eucalyptus grandis × Eucalyptus urophylla M.M. Van Dyk a, A.R.K. Kullan a, E. Mizrachi a, C.A. Hefer a, L. Jansen Van Rensburg a, D. Newman b, N. Coetzer c, T.J. Tschaplinski d, K.C. Cushman d, N.E. Engle d, G.A. Tuskan d, N. Jones e, A. Kanzler e, A. Bayley f, A.A. Myburg a a Department of Genetics, Forestry and Agricultural Biotechnology Institute (FABI), University of Pretoria, Pretoria, 0002, South Africa b Department of Plant Science, University of Pretoria, Pretoria, South Africa c Bioinformatics and Computational Biology Unit, Department of Biochemistry, University of Pretoria, Pretoria, South Africa d Biosciences Division, Oak Ridge National Laboratory, Oak Ridge TN 37831, USA e Sappi Forests Research, Shaw Research Centre, P.O. Box 473, Howick 3290, South Africa f Sappi Technology Centre, P.O. Box 6, The Innovation Hub, Lynnwood, Pretoria 0087, South Africa ★ Best poster presented by Nanette Coetzer – shared with Jonathan Botha Breeding of Eucalyptus hybrids for clonal forestry in subtropical regions of South Africa is aimed at combining the growth, form and rooting ability of E. grandis with the disease tolerance of E. urophylla. The underlying genetic basis of the observed hybrid superiority remains unclear. To identify genetic factors controlling growth and wood property traits in eucalypt hybrids, an F2 pseudo-backcross mapping family (n = 314) derived from a cross between an F1 hybrid (GUSAP1, E. grandis × E. urophylla, Sappi Forest Research) and an E. urophylla parent (USAP1) was used for genetic linkage map construction, using microsatellite (SSR) and Diversity Arrays Technology (DArT) markers. Phenotypic trait assessment for quantitative trait locus (QTL) analysis included physical measurements of tree diameter and wood density performed on three-year-old individuals. Klason (acid-soluble and -insoluble) lignin and cell wall sugar content were determined for a selection of 100 backcross progeny and used for near-infrared analysis (NIRA) calibration. NIRA predictions for glucose, xylose, arabinose, cellulose and total lignin content, as well as pulp yield were made for all individuals. Total lignin and S:G ratios were also separately measured for all individuals. Immature xylem tissues, collected from 192 backcross progeny, were used for metabolite profiling (ORNL, Oak Ridge, TN) and Illumina mRNA-Seq (15 million PE50, BGI Americas) quantification of transcript levels of more than 30,000 genes for which xylem expression was detected. To bridge the gap between fine mapping and QTL validation studies, transcript and metabolite levels were treated as quantitative traits and used for eQTL and mQTL mappings, respectively. Co-localization of wood property, expression and metabolite QTLs will facilitate the identification of positional candidate genes and other components of regulatory networks underlying phenotypic variation in this interspecific backcross pedigree. Ensemble optimisation of cis-regulatory element discovery: in planta benchmark and discovery in Eucalyptus I. Van Jaarsveld a,b, E. Mizrachi b, F. Joubert a, Y. Van de Peer c, A.A. Myburg b a Bioinformatics and Computational Biology Unit, Department of Biochemistry, University of Pretoria, Pretoria 0002, South Africa b Department of Genetics, Forestry and Agricultural Biotechnology Institute (FABI), University of Pretoria, Pretoria 0002, South Africa c Bioinformatics and Systems Biology, Plant Systems Biology Department, University of Ghent, Ghent 9000, Belgium Cis-regulatory motif discovery is extensively applied in the in silico analysis of plant promoters. This is a pattern recognition endeavor which ascribes regulatory function to subtly conserved 5–20 nt words. Guiding this approach is the “guilt-byassociation” assumption that regions in the promoters of coexpressed or orthologous genes bind the same or similar transcription factors, and so regulate gene expression. Numerous algorithms have been developed to detect regulatory motifs. Their performance is generally poor with sensitivity b 0.223 and precision b 0.308 in yeast, Drosophila, mouse and human. SAAB Conference Abstracts Despite this performance, the necessity for annotating transcription factor binding sites in hierarchical regulatory pathways, ensures that it remains a widely used practice. Spatial conservation of promoter motifs in plants is expected to be less than that of metazoans, as large-scale genome rearrangements and transposable element activity have engendered a loss of colinearity, expanded gene families, and resulted in poor conservation in proximal non-coding DNA. Before attempting cis-element discovery in E. grandis promoters, we are comprehensively benchmarking existing motif discovery algorithms on plant-specific, simulated and generic promoters. We aim to decipher the abilities and limitations of motif discovery tools in plants, and employ a synergistic ensemble implementation for secondary cell wall and cellulose biosynthesis related promoters in E. grandis trees. This will ensure as accurate as possible detection of regulatory motifs which are associated with the economically important properties of secondary cell walls in woody tissue, in this newly sequenced, fastgrowing and globally dominant plantation tree species. Effects of smoke-water and smoke-derived stimulants on rooting J. Van Staden, M.G. Kulkarni Research Centre for Plant Growth and Development, School of Life Sciences, University of KwaZulu-Natal Pietermaritzburg, Private Bag X01, Scottsville 3209, South Africa It is now well documented that smoke and smoke-derived compounds stimulate germination and in the process significantly increase root growth. When considering the literature it is clear that the effect on root growth per se has never been dissected properly. The main objective of this study was to test the effect of smoke-water and smoke-isolated butenolide (3-methyl-2H-furo[2,3-c]pyran-2-one) on root system of a wide range of plant species including agricultural and horticultural crops. Findings of these studies have shown that smoke solutions have an ability to stimulate rooting of a number of plant species. It is interesting to note that smoke solutions also showed an improvement of rooting under temperature and water stress conditions. The results of these studies are of considerable importance as root structure and developed forms the basis of successful plant establishment, nutrient mobilization and ultimate plant survival and crop production. Ethnobotany of the Cederberg B.-E. Van Wyk Department of Botany and Plant Biotechnology, University of Johannesburg, P.O. Box 524, Auckland Park 2006, South Africa The traditional uses of plants in the Cederberg region of the Western Cape Province, South Africa, are poorly documented. The Cederberg is well known as the source of commercial 219 natural products such as rooibos tea (Aspalathus linearis) and round leaf buchu (Agathosma betulina); some others are now obsolete, including ceder wood (Widdringtonia cederbergensis) and tan bark from waboom (Protea nitida), suikerbos (Protea neriifolia), kliphout (Heeria argentea) and pruimbas (Osyris compressa). This report forms part of an ongoing study to document the useful plants of the Cederberg as a contribution toward a more complete understanding of the broader patterns of traditional plant use in the Cape region. A checklist of more than 106 ethnobotanically relevant plant species has been compiled, including plants that are important as medicine or for wound healing, food, beverages, timber, firewood and several other everyday uses. Local inhabitants of the Cederberg (in villages such as Wuppertal, Heuningvlei and Kleinvlei) still regularly use indigenous plants. Until recently, these villages were isolated from the main centers (with no easy access to clinics and pharmacies) but an improved road system will undoubtedly result in the people becoming less dependent on indigenous plants so that the knowledge may gradually be lost. There is a need for quantitative studies to allow for comparisons between different communities and also between different generations. Characterization of the cysteine protease and cysteine protease inhibitor family in soybean nodules S.G. Van Wyk a , K.J. Kunert a , B.J. Vorster b a Department of Plant Science, University of Pretoria, Pretoria 0002, South Africa b Department of Plant Production and Soil Science, University of Pretoria, Pretoria 0002, South Africa Soybean (Glycine max) is one of the most important sources of vegetable protein for food and animal feed world-wide. The symbiotic relationship between soybean and the Rhizobia, Bradyrhizobium japonicum, enables soybean to assimilate fixed nitrogen in the root nodules. This symbiotic association allows soybean to be cultivated with reduced nitrogen supplementation, lowering production costs and maintaining high-protein yield. However, the nodule life is limited and sensitive to environmental stress. The plant cysteine protease-cystatin system plays an important role during plant development processes and has been shown to be involved in nodule senescence. The release of the complete genome data of soybean has allowed all putative cysteine proteases and cystatin sequences to be identified. However, it is not known whether all of these putative sequences are expressed, where and when they are expressed, or which cysteine proteases and cystatins are involved in nodule development and senescence. In soybean, only limited information is currently available about the expression of cysteine proteases with no cystatin expression data, despite soybean being one of the major crop plants in the world and of significant importance to South Africa. The hypothesis of this study is that there is a balanced interplay between individual cysteine proteases and cystatins during nodule 220 SAAB Conference Abstracts development, with changing expression profiles during nodule development and during senescence. The overall aim of the study will be to advance our knowledge regarding the cysteine protease–cystatin system in soybean and to establish a relationship between individual cysteine protease and cystatin expression during nodulation. Further characterization of the individual components of the protease–protease inhibitor system, might make it possible to silence a particular cysteine protease or recombinantly express a specific natural or engineered cystatin in soybean nodules that could possibly delay either natural or stress-induced nodule senescence. Effective invasive species management around protected areas: Understanding the spatial dynamics of Lantana camara invasions in South Africa's Kruger National Park W. Vardien a, D.M. Richardson a , L.C. Foxcroft a,b, J.R. Wilson a,c, J.J. Le Roux a a Centre for Invasion Biology, Department of Botany & Zoology, Stellenbosch University, Matieland 7602, South Africa b Conservation Services, South African National Parks, Skukuza 1350, South Africa c South African National Biodiversity Institute, Kirstenbosch National Botanical Gardens, Claremont 7735, South Africa Invasive plants are one of the greatest threats to biodiversity in Kruger National Park (KNP), South Africa's flagship protected area, primarily because of their impact on ecosystem services and functioning. The globally invasive and highly variable species complex, L. camara, is particularly troublesome in this regard. L. camara reproduces sexually and vegetatively, and is associated with multiple dispersal vectors. Here we use molecular techniques to explore how L. camara disperses in the KNP's Sabie-Sand River catchment, with the aim of providing management-relevant insights. The history of the species' presence in the park suggests either: a) downstream dispersal of seeds during normal flow and flood events, and/or b) long distance dispersal by vertebrates and wind. Using inter simple sequence repeat (ISSR) and amplified fragment length polymorphism (AFLP) molecular markers, we assessed population genetic structure and used it as a proxy for patterns of dispersal and to identify the main contributing sources of propagules. Our results indicate that genetic variation is partitioned largely within populations as opposed to between them. Populations located at the confluence of the Sabie and its main tributary, the Sand River, show the highest genetic diversity. We also found that populations along the Sand River contribute substantially more propagules to the lower reaches of the Sabie than the upper Sabie itself. Spatial analysis revealed a positive correlation between genetic and geographic distance along the river. The most likely spread scenario for L. camara in this area is continuous, from the Sand River subcatchment down into the lower Sabie River. However, only a small part of the Sand River falls under KNP management. We therefore recommend that control efforts should be focused on the parks' neighboring areas as well, if the spread and reinfestation of L. camara is to be minimized. Natural products in anti-obesity therapy – The good, the bad and the ugly I. Vermaak, A.M. Viljoen Department of Pharmaceutical Sciences, Tshwane University of Technology, Pretoria 0001, South Africa Obesity is a major health concern of modern times and should be considered a global epidemic. In 2005 it was estimated that 1.6 billion adults were overweight globally with at least 400 million classified as obese. Obesity is associated with and can lead to many disease conditions including type-2 diabetes, cardiovascular disease, hypertension, sleep apnea, and cerebrovascular accidents among many others. Conventional medicines used to treat obesity have high abuse potential and frequently exhibit side effects. The commercial market for anti-obesity preparations is enormous due to public awareness of the ill-effects of obesity and the general perception that being obese is less than attractive. This multibillion-dollar industry expands on a daily basis as new ‘miracle cure’ products become available. The continued search for new therapies has revealed multiple targets to combat obesity and highly complex plant extracts are ideally suited to fulfill a multi-targeted approach. Many herbal formulations are currently commercially available but most of them have been poorly researched in terms of efficacy and safety, if at all. Not surprisingly, associations between consumption of botanical products and instances of toxicity have been and are still being made. It is therefore imperative that these plants and derived herbal products be extensively investigated in terms of quality, efficacy, and especially safety in order to validate their widespread consumption. The phytochemistry, mechanism of action, in vivo efficacy or lack thereof and toxicity will be discussed for several of the most important plants to date used to treat obesity including: Camellia sinensis, Citrus aurantium, Ephedra sinica, Hoodia gordonii, Ilex paraguariensis and Panax ginseng. The application of vibrational spectroscopy and chemometrics in taxonomy A.M. Viljoen, M. Sandasi, J.E. Maree, N.P. Mncwangi Department of Pharmaceutical Sciences, Tshwane University of Technology, Private Bag X680, Pretoria 0001, South Africa Vibrational spectroscopy has been identified as an important quality control technique in the pharmaceutical, food and beverages, agriculture and mining industries. The diverse applications include; the inspection and identification of raw materials and quantification of active constituents or contaminants. The technique has gained popularity as it is nondestructive, inexpensive and requires minimal sample SAAB Conference Abstracts preparation. This work reports on the use of vibrational spectroscopy in the quality assessment of several commercially important South African species (Agathosma, Pelargonium, Salvia, Eriocephalus, Harpagophytum). Chemometric processing of the spectral data using orthogonal projections to latent structures (OPLS) discriminant analysis, partial least squares (PLS) and multivariate calibration models has shown that vibrational spectroscopy is a powerful technique to distinguish between closely related species. Alternative indigenous Rutaceous hosts of ‘Candidatus Liberibacter africanus’ and ‘Candidatus Liberibacter africanus subsp. capensis’ R. Viljoen a,b, E.T. Steenkamp a,b , G. Pietersen a,b,c a Department of Microbiology and Plant Pathology, University of Pretoria, Pretoria 0002, South Africa b Forest and Agricultural Biotechnology Institute, University of Pretoria, Pretoria 0002, South Africa c Agricultural Research Council – Plant Protection Research Institute, Pretoria 0002, South Africa ‘Candidatus Liberibacter africanus’ (Laf) is the causal agent of citrus greening disease in South Africa. This bacterium is of economical importance to the citrus industry as the disease it is associated with results in a considerable reduction in yield. A related bacterium, ‘Candidatus Liberibacter africanus subsp capensis (Laf C), is commonly associated with an indigenous member of the Rutaceae, C. capense. It has been postulated that Laf C may represent an ancestral form of Laf. This study aims to determine whether other alternative indigenous Rutaceous hosts exist that harbors either Laf or Laf C. 269 Vepris lanceolata, 135 Zanthoxylum capense and 75 C. anisata trees were sampled from across South Africa. These Rutaceous members were selected as the psyllid vector of Laf, Triozaerytreae, is capable of completing its life cycle on these trees. Total DNA was extracted from these samples which were then subject to a generic Liberibacter species real-time PCR. Samples with a Ct value of below 35 were considered positive. A conventional PCR specific for Liberibacters were then performed on these samples and directly sequenced thereafter to identify the Liberibacter species detected. Thus far LafC has been identified from 11 V. lanceolata trees collected from Knysna. Other samples are in the process of being screened. This is the first report of LafC being present in an indigenous Rutaceae other than C. capense. Laf has only been associated with citrus trees from various African countries including South Africa, Mauritius and Reunion Islands where citrus is not indigenous. Thus the possibility exists that Laf originated through a “host jump” from an indigenous bacterium onto citrus upon its introduction into the region. A thorough understanding into the host range of Laf will also aid in control of citrus greening disease. 221 Ug99 variants of Puccinia graminis f. sp. tritici in South Africa B. Visser a , L.J. Szabo b, L. Herselman a, Z.A. Pretorius a a Department of Plant Sciences, University of the Free State, Bloemfontein, South Africa b USDA-ARS Cereal Disease Laboratory, University of Minnesota, St. Paul, USA The discovery of the Ug99 wheat stem rust race in Uganda in 1999 heralded a new era for wheat rust research. Ug99 was the first race to possess virulence for Sr31, a durable and widely used stem rust resistance gene. Initial concerns about Ug99 in terms of food security were not completely unfounded, since not only has it spread to several African countries, Yemen and Iran, but seven variants in the Ug99 race group have also been described. Based on field tests in eastern Africa, 90% of the world's wheat varieties are susceptible to Ug99 and its related races. Even though wheat cultivation in South Africa is small compared to other countries, three of the seven Ug99 variants were originally identified in South Africa. Microsatellite analysis of South African stem rust races divided the population in two distinct groups. The first consisted of historically detected races whereas the second grouping contained the Ug99-related races, confirming the close relationship between Ug99 and its South African variants. Two of these races most probably represent exotic introductions into South Africa, while the third seems to be a single step mutation. In 2010, an eighth variant in the Ug99 lineage was identified in South Africa, when race TTKSF acquired virulence for an unknown resistance gene in a local cultivar. The application of new marker technology and implications of Ug99 diversity will be discussed. Plant cystatins and insect cysteine proteases: Weapons in a molecular arms race B.J. Vorster a, M-C. Goulet b, D. Michaud b a Department of Plant Production and Soil Science, University of Pretoria, Pretoria 0002, South Africa b Département de Phytologie, Faculté des Sciences de l'Agriculture et de l'Alimentation, Université Laval, Québec (QC) G1V 0A6, Canada On a molecular level the war between plants, and the insects that eat them, is akin to an arms race, with each organism continually striving to out match the other. One of the weapons in the arsenal of plants, targeted against the digestive proteases of herbivorous Coleoptera, such as the Colorado potato beetle, is cystatins or cysteine protease inhibitors. Cystatins are small proteins that act as natural inhibitors of cysteine proteases, thereby disrupting the digestion of plant material by insects such as the Colorado potato beetle. However, the Colorado potato beetle is able to compensate towards the presence of dietary protease inhibitors in plant tissues through a multi-component defensive strategy involving the over-expression of inhibitor- 222 SAAB Conference Abstracts sensitive digestive proteases, the expression of proteases insensitive to the inhibitors as well as through proteolytic inactivation of the inhibitory proteins using non-target proteases. More than 30 digestive cysteine proteases have been identified so far in the potato beetle, in line with the observed ability of this insect to elude the detrimental effects of cystatins induced in wounded potato leaves. Our goal, in this study, was to determine whether functional diversity of the potato beetle digestive cysteine protease complement was matched with similar functional variability of the potato host cystatin complement, using the wound-inducible eight-domain potato multi-cystatin (PMC), as a model. Computational modeling of the PMC domains interacting with cysteine proteases of the beetle suggested the onset of variable interaction strengths for the PMC domains, then confirmed empirically with protease inhibitory data showing complementary protease inhibitory spectra among the eight domains. This data suggest, overall, that functional variability among PMC inhibitory domains has evolved in response to predatory challenges by the Colorado beetle relying on cysteine proteases for potato leaf protein digestion. Is frost a demographic bottleneck for savanna trees? Testing the effect of freeze events on Colophospermum mopane population structure in Limpopo Province, South Africa M. Whitecross a , S. Archibald b, E.T.F. Witkowski a a School of Animal, Plant and Environmental Sciences, University of the Witwatersrand, Johannesburg 2050, South Africa b Natural Resources and the Environment, CSIR, P.O. Box 395, Pretoria 0001, South Africa ★ Best oral paper presented by a young scientist Frost disturbance is often mentioned in southern African savanna literature, but is seldom discussed in great detail. Nevertheless, it can represent an above-ground disturbance as effective as fire depending on the resistance capacity of the effected tree species. A severely freeze damaged stand of C. mopane in the Venetia Limpopo Nature Reserve provided an opportunity to investigate the mechanisms behind freeze damage impacts on C. mopane. Frost may therefore act as a possible demographic limitation of C. mopane in preventing its southwards spread. Freeze damage of individual trees was assessed according to tree height and landscape position – with lower elevations representing the most severe freeze zones and higher elevations the least severe freeze zones. A high freeze severity threshold (558.75 m.a.s.l.) and a low freeze severity threshold (564 m.a.s.l) were found to distinguish between populations of smaller, coppicing trees at lower elevations, and taller, non-coppicing trees at higher elevations. Little freeze damage was observed on tree canopies above 4 m in height. Trees below 4 m that had experienced 100% freeze damage, failed to regrow to their original heights from the previous season. This is a possible driver of the pre-freeze height differences seen across the slope; with low elevation trees having to recover from freeze events more frequently, and subsequent topkill resulting in a decrease in height over time. Taller trees at higher elevations experience less freeze damage and can grow beyond the 4 m freeze zone which decreases their chance of severe topkill and stunted growth. Long term effects linked to heights and densities suggested fewer, smaller trees at lower elevations due to relatively higher freeze frequency impacts. It appears C. mopane has limited resistance to freeze events, and this may be linked to the absence of this species at colder latitudes in the Southern Hemisphere. Biological invasion assessment and eradication – A national programme to reduce South Africa's invasion debt J.R. Wilson a,b, P. Ivey a, I. Nänni a, P. Manyama a a South African National Biodiversity Institute, Kirstenbosch Research Centre, Claremont 7735, South Africa b Centre for Invasion Biology, Department of Botany and Zoology, Stellenbosch University, Private Bag X1, Matieland 7602, South Africa The number of biological invasions in South Africa is increasing as introduced species naturalize. Naturalized species become invasive, and species which are invasive in small areas become much more widespread. Therefore, even if there are no new introductions, this country has a massive invasion debt. However, to date, most management and research has focused either at the border or after species have become widespread. What has been missing are general post-border assessments of the risks posed by introduced species, and the consideration of eradication as a management goal where feasible. To address this, a national programme of Early Detection and Rapid Response was initiated in 2008. In this talk we discuss the rationale for such an approach, how it was achieved, and progress to date. We use Australian acacias as a casesystem to explore some of the main issues. The transition of SANBI's herbaria from PRECIS to a BRAHMS database management system P.J.D. Winter Biodiversity Information Management Directorate, Kirstenbosch Research Centre, SANBI, Cape Town The PRECIS database was an international leader in its class for several decades (1974-1990), but with the field of databases moving more into the realm of PC's, Windows, Internet, and general connectivity, it failed to progress much beyond a mainframe database model where users have only limited access to the data holdings. Other databases were in a better position to make use of technological advances, and have overtaken it. Currently on an InterBase and Delphi platform, the expertise of developing PRECIS to user's needs is no longer available or cost-effective. There has been a steady increase in demand among our users (for at least the last seven years) for the SAAB Conference Abstracts basic type of relational database functionality from PRECIS that could no longer be supplied with the InterBase/Delphi system given the resources available for its operation and management. SANBI will provide a herbarium collection data service that meets the current demand of users, and is built upon the sound management, staffing and operation of a core BRAHMS database. This will be the preferred national plant information system to support the capture and management of fundamental taxonomic, specimen and floristic information for SA. The project involves an integration of data from several sources in SANBI. Some of this data will be centralized, while others will be brought in as needed from external sources. The benefits and risks associated with centralization are discussed. The role of megaherbivores in shaping the structure of subtropical plant communities K. Yessoufou a,b, O. Maurin a,b, T.J. Davies c , M. Kuzmina d, H. Schafer e, M. Van der Bank a,b, V. Savolainen f a African Center for DNA Barcoding, University of Johannesburg, Department of Botany and Biotechnology, P.O. Box 524, Auckland Park 2006, South Africa b Department of Botany and Plant Biotechnology, University of Johannesburg, P.O. Box 524, Auckland Park 2006, Johannesburg, South Africa c McGill University, 1205 Avenue Docteur Penfiel, Montreal, Quebec, Canada d Canadian Centre for DNA Barcoding, University of Guelph, 50 Stone Road East, Guelph, N1G 2 W1, Canada e Harvard University, 22 Divinity Avenue, Cambridge 02138, USA f Imperial College London, Silwood Park Campus, Ascot SL5, UK The assembly of organisms into communities is influenced by a variety of ecological and climatic factors, but evolutionary relationships also play a key role in shaping the structure of these assemblages. Examining phylogenetic trees of species within communities provides a framework in which processes such as competition or adaptation leave distinct signatures – an approach that has been successfully applied to describe the patterns of a few rainforests, microbial and animal communities. However, understanding the processes underlying phylogenetic community structure has been hampered by a lack of long-term experiments to test complex biotic interactions. We analyzed plant communities of the subtropical savanna–woodland biome of southern Africa, renowned for its large mammalian fauna. Reconstructing the phylogeny of species of trees and shrubs based on DNA barcodes data and measuring multiple defense strategies, we then compared the phylogenetic structure of these communities under various pressures of herbivory, including ‘exclosures’ where megaherbivores have been denied access for decades. We demonstrate that heavy pressure from generalist megaherbivores shapes the structure of plant assemblages, favoring clusters of closely related species, while also 223 increasing functional diversity and providing a buffer to disturbances. Our results provide the first empirical test of theoretical expectations for the effect of herbivory on community structure. These results help understand the evolution of savanna– woodlands under drivers of change, while shedding new light on how management of large game animals, such as elephants, impacts biodiversity conservation in these habitats. The molecular and metabolite profiling of grapevine berries in a model vineyard where the microclimate of the developing bunches has been altered P. Young a,b, E. Alexandersson c, D. Jacobson a,b, J. Lashbrooke a,b, Z. Coetzee b, A. Deloire b, M. Vivier a,b a Institute for Wine Biotechnology and bDepartment of Viticulture and Oenology, Stellenbosch University, Private Bag X1, Matieland 7602, South Africa c Department of Plant Protection Biology, Swedish University of Agricultural Sciences, SE-230 53 Alnarp, Sweden An estimation of grape composition is considered to be essential in establishing grape quality. Grape composition is influenced by a number of factors and can to a certain extent be manipulated in the vineyard by viticultural management practices. This study investigated the molecular response of V. vinifera cv. Sauvignon blanc berries to treatments that led to an altered microclimate in the bunch zone of a highly characterized vineyard setting (i.e. a model vineyard). The carotenoid biosynthetic pathway was investigated due to its crucial role in photosynthesis (especially photoprotection); as well as its role in the formation of the norisoprenoids: compounds formed by the degradation of carotenoids and responsible for the characteristic flavor and aroma of certain cultivars. Pathway analysis was used to analyze the expression of the carotenoid biosynthetic genes at three time points during berry development using grape whole genome arrays. The photosynthetic pigments were analyzed and the concentrations in the berries correlated to gene expression. The altered microclimate in the bunch zone resulted in significant changes in gene expression and carotenoid and chlorophyll concentrations. The expression of the genes involved in specifically the xanthophyll cycles, as well as the photoprotective xanthophylls was differentially affected in the treated grapevines, relative to control plants. This approach proved valuable to understand the molecular response of developing grape berries and the impact of changing environmental conditions. Pharmacological and phytochemical analysis of a medicinal plant mixture that is used as traditional medicine in Western Cape S. Zonyane a, S.F. Van Vuuren b, N.P. Makunga a a Department of Botany and Zoology, Stellenbosch University, Private Bag X1, Stellenbosch 7600, South Africa 224 SAAB Conference Abstracts b Department of Pharmacy and Pharmacology, Faculty of Health Sciences, University of the Witwatersrand, 7 York Road, Parktown 2193, South Africa In traditional medicine, different plant species which are often not related are combined as to enhance the efficacy of a medicinal preparation. As part of indigenous herbal knowledge, it is believed that better therapeutic effects are derived from synergistic interactions between different plant constituents. However, there are few studies which have confirmed this practice as it is mainly single plant extracts that are screened for bioactivity in South Africa. We thus investigated a plant mixture which consisted of three plant species; Agathosma crenulata, Dodonaea viscosa and Eucalyptus globulas for synergistic interactions. This plant combination was the most potent out of eight plant mixtures which were screened for antibacterial activity, with MIC value of 0.049 against S. aureus and Bacillus subtilis. Individual plant extracts were not as effective as the whole plant combination. An in-depth investigation of phytosynergism in this plant combination using different combinations and ratios was conducted. Fractional inhibitory concentrations (FIC) for two-plant combinations revealed enhanced activity when plants are combined (FIC values ranged from 0.079 to 0.750). The combination of D. viscosa and E. globulas (0.079) exhibited the strongest synergistic interaction while the combination of D. viscosa and A. crenulata was mildly synergistic for all test bacteria. Combining plants into a mixed herbal preparation was beneficial for improving the action of plant mixtures as individual plants were less active on their own. Poster abstracts Effects of long-term storage on antimicrobial and cyclooxygenase-1 inhibitory activities of South African medicinal plants S.O. Amoo, A.O. Aremu, M. Moyo, J. Van Staden Research Centre for Plant Growth and Development, School of Life Sciences, University of KwaZulu-Natal Pietermaritzburg, Private Bag X01, Scottsville 3209, South Africa The antimicrobial and cyclooxygenase-1 (COX-1) inhibitory activities of 50% methanolic extracts obtained from ten different medicinal plants stored for 16 years at room temperature were compared to those of fresh plant materials collected from the same locations. The plants evaluated are traditionally used for treating pain and infection-related ailments and they included Acokanthera oppositifolia, Artemisia afra, Buddleja salvifolia, C. anisata, Dombeya rotundifolia, Ekebergia capensis, Ocotea bullata, Protorhus longifolia, S. africana and Tetradenia riparia. Lower minimum inhibitory concentrations (MICs) against S. aureus were observed in stored plant materials of all the species except A. afra and P. longifolia when compared to the respective fresh materials. With the exception of D. rotundifolia and P. longifolia, the MICs of the stored plant materials against both C. albicans and P. aeruginosa were either lower than or the same as those of fresh materials. The percentage COX-1 inhibition values of the stored plant materials were generally higher than their respective fresh materials. Current findings indicate that stored plant materials may retain their biological activities over a period of time. Better activities observed in majority of the stored plant materials are probably due to the production of more potent metabolites arising from the breakdown of some constituent chemicals. Stimulatory role of karrikinolide (KAR1) and smokewater on photosynthetic pigment and phenolic contents of micropropagated ‘Williams’ bananas M.W. Bairu, A.O. Aremu, J. Van Staden Research Centre for Plant Growth and Development, School of Life Sciences, University of KwaZulu-Natal Pietermaritzburg, Private Bag X01, Scottsville 3209, South Africa At low concentrations, smoke-water (SW) and smokederived karrikinolide (KAR1) are compounds with potential cytokinin- and auxin-like activity. In comparison with metatopolin (mT), their role on the growth, photosynthetic pigment and phenolic contents of micropropagated ‘Williams’ bananas was investigated. Explants were cultured in modified Murashige and Skoog (MS) basal media supplemented with either SW (1:125; 1:250; 1:500; 1:1000; 1:2000 dilutions) or KAR1 concentrations ranging from 3.3 × 10 - 12 to 1.2 × 10 - 24. After 42 days, growth parameters were measured while the photosynthetic pigments and phenolic contents were determined using spectrophotometric methods. The photosynthetic pigments chlorophyll a, b and total carotenoid contents were significantly improved by KAR1 (4.8 × 10 - 22) and SM (1:125 and 1:1000). These treatments were approximately two-fold and three-fold better than the control and mT, respectively. Total phenolic content was highest in KAR1 at 1.0 × 10 - 19 and 7.8 × 10 - 17 for the leaves and roots, respectively. Furthermore, KAR1 at 1.0 × 10 - 19 had a significantly higher amount of total flavonoids and proanthocyanidin in the root parts. At 1:500 dilutions SM stimulated the highest amount of total flavonoids in the leaves across the treatments. Since photosynthetic pigments and phenolic compounds play a significant role in the growth, defense and survival strategy of plants, the findings of this study will have practical significance for the acclimatization of micropropagated plants. The results are also demonstration of the potential of smoke as an eliciting agent. Somatic embryogenesis and plant regeneration from leaf explants of Merwilla plumbea (Lindl.) Speta P. Baskaran, J. Van Staden Research Centre for Plant Growth and Development, School of Life Sciences, University of KwaZulu-Natal Pietermaritzburg, Scottsville 3209, South Africa SAAB Conference Abstracts M. plumbea, a popular but threatened medicinal plant in South Africa, was investigated for somatic embryogenesis by cell suspensions and plant regeneration. Embryogenic callus was initiated from in vitro grown M. plumbea leaf explants on agar-solidified MS medium containing 8.3 μM picloram, 2.3 μM thidiazuron (TDZ) and 20 μM glutamine. Callus was subsequently proliferated on solid medium containing 4.1 μM picloram, 2.3 μM TDZ and 20 μM glutamine before transfer to liquid MS medium supplemented with 0.4 μM picloram and 0.9 μM TDZ for somatic embryo development. The highest frequency of somatic embryogenesis (5.4-35.6, globular to cotyledonary somatic embryos/settled cell volume (SCV)) was induced on liquid medium containing 0.4 μM picloram and 0.9 μM TDZ and 150 mg l - 1 hemoglobin. The embryos were regenerated (94.4%) into plantlets on solid media containing 1.4 μM gibberellic acid. The plantlets were grown further on half-strength MS medium and successfully acclimatized. This is the first report on induction of M. plumbea somatic embryogenesis. The protocol developed offers a viable means for mass propagation and germplasm conservation, and it provides a system for physiological, biochemical, molecular and cellular studies of embryo development. Soil factors influencing the distribution of Portulacaria afra in subtropical thicket C.H. Becker a,b, C. Coetsee b, R.M. Cowling a a Department of Botany, Nelson Mandela Metropolitan University, P.O. Box 77000, Port Elizabeth 6031, South Africa b School of Natural Resource Management, Nelson Mandela Metropolitan University, Private Bag X6531, George 6530, South Africa Subtropical thicket in South Africa has been heavily degraded and transformed to an open desert like state, with a major loss of the succulent P. afra. Restoration of thicket can be achieved by planting P. afra cuttings, and this study aims to investigate the relationship between selected soil properties and P. afra, over a range of soil types and landscape positions, to aid in the identification of the most appropriate restoration sites. It investigates P. afra occurring in both natural stands and in restoration sites; to determine factors that influence its distribution. Observations and research show that P. afra dominates crests of hills and decreases with distance down slope; that it prefers growing on north facing slopes and barely exists on south facing slopes; that it's tolerant of a wide range of soil conditions but thrives on rocky, dry soils and avoids soils that may be seasonally waterlogged. It appears to survive better in conglomerate soils than in alluvial soils and a possible clear indication is that sodium concentrations could be a controlling factor. The data collection is split into three parts, whereby 1) in experimental plots P. afra cuttings planted in different soil types are subjected to different levels of salinity; 2) on a landscape level ten sites between Grahamstown and Calitzdorp are analyzed to determine which factors (aspect, gradient, soil 225 depth, water infiltration and soil texture and sodium levels) could be important in driving distribution; and 3) intensive studies on north and south facing slopes at three of Working for Water's restoration sites whereby soil is analyzed for macro-nutrients, particle size, texture, and pH. This will combine with the survival rates of P. afra determine if its distribution is related to soil nutrients or physical properties of the soil and if it's avoiding soils with higher concentrations of sodium. Description of novel Burkholderia species associated with the root nodules of indigenous Hypocalypteae and Podalyrieae C.W. Beukes, L. Mthombeni, E. Van Zyl, S.N. Venter, E.T. Steenkamp Department of Microbiology and Plant Pathology, Forestry and Agricultural Biotechnology Institute (FABI), University of Pretoria, Pretoria 0002, South Africa Most legumes can establish nitrogen-fixing symbioses with root–nodule bacteria. This group of bacteria can represent either Alpha- or Betaproteobacteria. Although much is known regarding root–nodule bacteria of agriculturally important legumes, the nitrogen-fixing symbionts of hosts indigenous to South Africa remains to be characterized. The research in this study focused on the rhizobial symbionts of the three indigenous Hypocalyptus species (subfamily Papilionoideae, tribe Hypocalypteae) as well as those associated with species in the genera Virgilia, Podalyria and Cyclopia (subfamily Papilionoideae, tribe Podalyrieae). A set of 69 rhizobial isolates were obtained from these hosts and shown to be capable of nodulating their original hosts, as well as the promiscuous legumes siratro (Macroptilium atropurpureum) and cowpea (V. unguiculata). To characterize and describe these bacteria, we utilized a polyphasic approach in which both the phenotypic and genotypic traits were studied. DNA sequence and phylogenetic analyses for four housekeeping genes (16S rRNA, recA, rpoB and atpD) placed all of the isolates into the genus Burkholderia. From these data we distinguished 25 distinct rhizobial lineages, which were also supported by a range of phenotypic characters (e.g., cultural growth properties and metabolic abilities). However, the majority of these lineages apparently lacked close relationships with known species of Burkholderia. The uniqueness of the isolates examined in this study was also reflected in the phylogenies for a nodulation gene, nodA, and a gene involved in nitrogen-fixation, nifH. The root–nodule bacteria examined in this study are thus unlike other Burkholderia species, not only in terms of their housekeeping genes and functions, but also with respect to the information located on their symbiotic loci. Taken together, our results suggest that the Burkholderia species associated with indigenous legumes have African origins and that both horizontal and vertical gene transfers determine the evolution of their symbiotic abilities. 226 SAAB Conference Abstracts Sustaining Gnetum L. in Africa through improved taxonomy and domestication E.H. Biye, K. Balkwill, G.V. Cron School of Animal, Plant and Environmental Sciences, University of the Witwatersrand, Private Bag 3, WITS 2050, Johannesburg, South Africa The African species of Gnetum L. (Gnetales) are lianas in the humid tropical forests of Central and West Africa. These gymnosperms are nutritionally and economically valuable and contribute greatly to poverty alleviation of the local people as they are widely used as a vegetable (‘eru’). The African species of this genus are however difficult to distinguish from one another, and are threatened due to over-exploitation and face the risk of disappearing before they are sufficiently known. The names Gnetum africanum Welw. and G. buchholzianum Engl. have been interchangeably applied on specimens that apparently represent similar forms of Gnetum in Africa and this has resulted in taxonomic confusion. This study aimed to clarify the taxonomy of the African species of Gnetum and to promote sustainable utilization and conservation of the species. An evaluation of variation in taste among Gnetum populations was performed to identify the best tasting species for cultivation. Cluster analyses using morphological characters were carried out to investigate the variation among the African populations and to reveal additional characters to differentiate the species for both male and female plants. Molecular markers (AFLPS) were also used to clarify species boundaries. Reproductive structures were found to be most useful in distinguishing species and the applications of the names G. africanum and G. buchholzianum were clarified and two new African species have been described: Gnetum interruptum E.H. Biye sp. nov. and Gnetum latispicum E.H. Biye sp. nov. Taste analyses identified the leaves of G. buchholzianum and young leaves in general as best for an ‘eru’ (Gnetum) meal. This has implications for cultivation and harvesting methods. Promoter analysis of the Eucalyptus grandis secondary cell wall related SND2 transcription factor gene J. Botha a,b , D. Pinard a,b, N. Creux a,b, S. Hussey a,b, C. Maritz-Olivier a, E. Mizrachi a,b, A.A. Myburg a,b a Department of Genetics, University of Pretoria, Pretoria 0002, South Africa b Forestry and Agricultural Biotechnology Institute (FABI), University of Pretoria, Pretoria 0002, South Africa ★ Best poster presented by Jonathan Botha – shared with Nanette Coetzer NAC and MYB transcription factors (TFs) are important components of the regulatory network controlling secondary cell wall (SCW) biosynthesis in plants. Arabidopsis SND2, SND3 and MYB103 are targets of the wood fiber SCW master regulators NST1 and SND1, and are thought to play a role in cellulose biosynthesis in fiber cell walls. Recent studies have shown that although much of this regulatory network is conserved between herbaceous and woody model species, there may be unique TFs or combinations of TFs that are important for regulating xylem deposition in wood fibers. It is hypothesized that there is an analogous regulatory network in the commercially important tree genus Eucalyptus, which remains to be characterized. In this study we aim to identify cis-regulatory sequences in the promoter regions of the E. grandis EgrSND2, EgrSND3 and EgrMYB103 genes, to characterize the expression patterns of these promoters in Arabidopsis and to identify specific TF-promoter interactions of EgrSND2 using a yeast-1hybrid (Y1-H) approach. Using the RSA tools suite (http://rsat. ulb.ac.be), several previously described and novel cis-elements were identified in all three Eucalyptus promoters. Promoter sequences (1.5 kb upstream of the translational start site) of the three transcription factors were amplified and fused to the βglucuronidase (GUS) reporter gene for expression analysis in transgenic Arabidopsis plants. All three promoters were able to drive strong reporter gene expression, but not in a fiber-specific fashion as expected. This may be caused by a lack of a fiber-specific element or combination of elements in the promoter sequence investigated, or may be due to a functional or regulatory divergence of Eucalyptus and Arabidopsis promoters. Using a yeast one-hybrid analysis (Y1-H), we aim to detect direct interaction of several upstream SCW associated TFs with the promoter of EgrSND2 in order to characterize its central role in the SCW transcriptional network. Plant diversity of vegetation-over-ultramafic soil in Mount Bulanjao, Palawan Island, Philippines R.R. Castillo a, W.S.M. Gruèzo b a Center for Strategic Policy and Governance, Palawan State University, Puerto Princesa City 5300, Palawan Island, Philippines b Plant Biology Division, Institute of Biological Sciences, College of Arts & Sciences, University of the Philippines Los Baños, College 4031, Laguna, Philippines Mount Bulanjao is a low mountain (highest peak – 1036 masl) with extant natural vegetation-over-ultramafic soil in the Municipalities of Bataraza and Rizal, Palawan Island, Philippines. Results of the assessment and characterization of plant diversity and vegetation types of this mountain showed a relatively high diversity level of H′ = 4.17. A total of 193 plant species belonging to152 genera and 73 families were recorded from the study area based from a total of 33 (10 × 10 m) sample plots. The dominant plant forms are trees with 117 species followed by vines (30 species), herbs (25 species) and shrubs (21 species). In terms of importance value per habit type, Alstonia macrophylla (Apocynaceae), Xanthostemon sp. (Myrtaceae), Dillenia monantha (Dilleniaceae) ranked top for trees; Dracaena angustifolia (Agavaceae), Pandanus luzoniensis (Pandanaceae), Melastoma sp. (Melastomataceae) SAAB Conference Abstracts for shrubs; Fimbristylis globulosa (Cyperaceae) Zingiber sp. (Zingiberaceae), Imperata cylindrica (Poaceae) for herbs and Dinochloa acutiflora (Poaceae), Calamus sp. (Arecaceae) and Lygodium circinatum (Schizaeaceae) for climbers. Additional noteworthy plants of these vegetation-over-ultramafic soil are Brackenridgea palustris subsp. foxworthyi (Ochnaceae), Eurycoma longifolia (Simaroubaceae), Gymnostoma rumphiana (Casuarinaceae), Jasminum aemulum (Oleaceae), Messersmidia argentea (Boraginaceae), Gymnostachyum pictum (Acanthaceae), Wrightia hanleyi (Apocynaceae), Scaevola micrantha (Goodeniaceae), Protium connarifolium (Burseraceae) and Phyllanthus balgoyii (Phyllanthaceae). The results of the study showed that vegetation of Mt. Bulanjao is still intact, with types belonging to those of primary to secondary forests-over-ultramafic soil to a large extent, with grassland and brushland as well as riparian formation. All these vegetation types are still capable of providing excellent niches for the wildlife fauna of this endangered mountain ecosystem. Plant composition and diversity of forests-over-ultramafic soil in Mt. Victoria Range, Palawan Island, Philippines R.R. Castillo a, W.S.M. Gruèzo b a Center for Strategic Policy and Governance, Palawan State University, Puerto Princesa City 5300, Palawan, Philippines b Plant Biology Division, Institute of Biological Sciences, College of Arts and Sciences, University of the Philippines Los Baños, College 4031, Laguna, Philippines Mount Victoria is a medium-sized mountain range (with peaks ranging from 1500 to 1726 masl) straddling the Municipalities of Aborlan, Narra and Quezon, Palawan Island, Philippines. Generally, a greater portion of the mountain range harbors the largest nickel deposit in Palawan Island. A mixed broad leafed forest-over-ultramafic soil is present in this mountain range from sea level to 700 m elevation but with apparently two altitudinal zones of plant diversity. At lower elevations (0–300 masl) of this mountain, a forest zone is present which is composed of 141 tree, 32 herb, 27 vine and 22 shrub species, for a total of 222 species belonging to 174 genera and 75 families. The four most dominant species in this lower forest zone are Xanthostemon speciosum, Tristaniopsis decorticata (Myrtaceae); Casuarina equisetifolia (Casuarinaceae) and Swintonia foxworthyi (Anacardiaceae). It had a relatively high diversity level of H′ = 4.25. In the upper elevations (400 to 700 masl), a total of 81 species belonging to 67 genera and 46 families were recorded, composed of 50 tree, 13 vine, 11 shrub and 7 herb species. The dominant species in this zone are C. equisetifolia (Casuarinaceae), T. decorticata (Myrtaceae), Myristica guatteriaefolia (Myristicaceae) and D. acutiflora (Poaceae). This upper forest zone had a diversity index value of H′ = 3.76, which is slightly lower compared to the lower forest zone. 227 Micro RNA expression in maize leaves and flowers B.G. Crampton a, S.L. Murray b,c a Department of Plant Science, Forestry and Agricultural Biotechnology Institute, University of Pretoria, Pretoria 0002, South Africa b Centre for Proteomic and Genomic Research, P.O. Box 81, Observatory, Cape Town 7945, South Africa c Department of Molecular and Cell Biology, University of Cape Town, Rondebosch 7700, South Africa Micro RNAs are approximately 20–22 nucleotides in length, and act as master regulators of gene expression. Micro RNAs recognize complementary mRNAs and bind to them by base-pairing, thereby regulating expression of the mRNA, either by blocking translation or by cleavage and subsequent degradation of the mRNA. In order to investigate the role of microRNAs in maize development, we employed Exiqon miRCURY LNA arrays (www. exiqon.com) and profiled micro RNA expression in leaves and male and female flowers. These arrays contain probes for micro RNA genes listed in the database miRBase (www.miRBase. org), and are representative of micro RNAs identified in all eukaryotic species. Comparison of micro RNA profiles of leaves and male and female flowers indicated that nine micro RNA genes were up-regulated in both male and female flowers relative to leaves, whereas nine and 25 genes were up-regulated only in either in male or female flowers respectively. We obtained similar results for down-regulated micro RNA genes. Of particular interest is the up-regulation of zma-MIR166, and members of the zma-MIR171 family, both of which have previously been shown to play a role in flower development. This study emphasizes the utility of microarrays in rapid identification of micro RNAs and in profiling micro RNA gene expression in plant tissues. Emilia (Cass.) Cass. (Asteraceae, Senecioneae) in southern Africa G.V. Cron School of Animal, Plant and Environmental Sciences, University of the Witwatersrand, Private Bag 3, WITS, Johannesburg 2050, South Africa Emilia (Cass.) Cass. (Asteraceae, Senecioneae) is a tropical herbaceous genus comprising about 100 species, most of them African. The mostly glabrous herbs are annual or perennial with variable leaf forms. Similarly, the capitula may be solitary or few to several in lax corymbs, radiate or discoid, and the florets range from white to pink, red, orange or rarely yellow. Chromosome numbers also vary considerably within the genus. Distinguishing features include the ecalyculate capitula, elliptic-oblong cypselas with an obscure carpopodium and a pappus of slender, persistent bristles. Twenty species of Emilia occur south of the DRC and Tanzania, including seven from southern Africa (Botswana, Namibia, South Africa and Swaziland). Emilia hantamensis from near Nieuwoudtville 228 SAAB Conference Abstracts was thought to be the first record of the genus from the winter rainfall region of South Africa with a large disjunction between it and either Emilia transvaalensis (northern KwaZulu-Natal and Gauteng) or Emilia ambifaria (North West Province). It has large, yellow radiate capitula - quite distinct from the other discoid, purple or white-flowered Emilia species in South Africa. This study aimed to investigate whether E. hantamensis was more closely related to the other radiate members of the genus Emilia (the nearest being Emilia discifolia in Zimbabwe), or to the southern African discoid species. Phylogenies based on nuclear markers have revealed that E. hantamensis is not a member of Emilia at all, but a distinct genus closely related to Bolandia, Mesogramma and Stilpnogyne. Socioeconomic gradients, garden design and plant diversity patterns in urban areas in the North-West Province and Gauteng E. Davoren, S.S. Cilliers, S.J. Siebert School of Environmental Sciences and Development, NorthWest University, Private Bag X6001, Potchefstroom 2520, South Africa In contrast to the main focus of studies in developed countries, home garden research over the last three decades in developing countries has been aimed primarily at either ethnobotanical documentation of the diversity and uses of garden species, or the promotion of home gardening for nutritional improvement of lowincome groups. Similarly in South Africa the majority of studies have focused on the value of cultivated floras in home gardens of rural areas for household consumption and poverty alleviation, the cultivation of medicinal plants as a tool for biodiversity conservation and indigenous knowledge research. Between 2007 and 2010 several home garden projects have been and are still being conducted by the Urban Ecology Research Group at the NorthWest University. The overall objective of these studies was to develop a better understanding of the plant diversity of home gardens, their contribution to urban plant diversity, as well as their structure and function in a city, town, rural settlement and deeprural area. The current study aims to compare garden design (traditional European approach versus a specific local ethnical approach, e.g. “tshimos”) and plant diversity with the mentioned home garden studies along a socioeconomic gradient. Socioeconomic status is determined using variables such as monthly income, income generation, total number of residents per house, modes of transport and schooling status. The degree of urbanization surrounding the home gardens is also important and was quantified using fourteen demographic, physical and landscape metrics measures. The completed and ongoing studies provide a large dataset of home garden floras and the socioeconomic aspects of the rural, peri-urban and urban environments. Results have indicated correlations between species diversity (total, native, alien, medicinal, ornamental, vegetable, fruit trees), type of garden design, socioeconomic status and degree of urbanization. De novo assembly of the expressed gene catalogue of Equisetum ramosissimum A. Dos Santos a, E. Mizrachi b, C.A. Hefer a, A.A. Myburg b a Bioinformatics and Computational Biology Unit, Department of Biochemistry, University of Pretoria, Pretoria 0002, South Africa b Department of Genetics, University of Pretoria, Pretoria 0002, South Africa Horsetails (Equisetum spp.) represent some of the earliest and most dominant vascular plants of the early carboniferous. They diverged more than 360 mya from the rest of the ferns and have remained relatively unchanged since. In addition to their important phylogenetic position in the evolution of plant vasculature, horsetails possess unique cell wall properties that could provide insight into the evolution of cell walls in plants. High-throughput transcriptome sequencing using Illumina mRNA-Seq presents the opportunity to explore entire transcriptomes in a high-throughput and relatively low cost manner. However, the de novo assembly of transcript-derived shortread data presents new challenges, including variable coverage across assembled contigs, reads derived from alternatively spliced transcripts, as well as sampling bias of highly expressed genes. A gene catalog of E. ramosissimum was assembled from ~ 220 million, 80 bp paired-end Illumina high quality reads (8.8 Gbp) generated from stem- and sporangiophore-derived cDNA. The depth of sequencing and high quality of the reads offered an opportunity to gain insight into the efficiency of some of the available software for the complex task of assembling short-read data, while simultaneously providing a resource to answer further biological questions. Trans-ABySS, Trinity, Oases and Velvet assemblers were compared using standard sequence assembly metrics including N50, L50, median contig length, proportion of incorporated bases and total number of assembled contigs. Assembled gene catalogs were also evaluated according to annotation, such as predicted coding sequence and significant blast hits to other sequenced plant transcriptomes. Oases was found to produce the highest quality assembly in terms of contig contiguity and total amount of unique transcriptome assembled when compared to the other assemblers. The final assembly was annotated using BLAST2GO and InterProScan. The results include a comprehensive expressed gene catalog of E. ramosissimum comprising of 26,318 non-redundant contigs with a median contig length of 1027 bp and total size of 34 Mbp, which could shed light on many aspects of vascular plant evolution, as well as the unique biology of horsetails. Potential of two South African plants belonging to the Greyiaceae family for the treatment of skin hyper-pigmentation M. De Canha, N. Lall Department of Plant Science, University of Pretoria, Pretoria 0002, South Africa SAAB Conference Abstracts Melanin biosynthesis is regulated by the tyrosinase enzyme, which is responsible for the catalysis of the rate limiting step in the melanin biosynthetic pathway. In humans, melanin biosynthesis takes place within the skin melanocyte cells. Ten percent propane-1, 2-diol (PG) leaf extracts of two plants (S1 and S2) belonging to the Greyiaceae family were screened for antityrosinase activity, mutagenicity, stability and irritancy. Ten percent PG: deionized water extracts for S1 and S2 showed approximately 98% inhibition of the tyrosinase enzyme. Samples were compared to that of known inhibitor Kojic Acid which exhibited an IC50 of 2.841 μg/ml. Stability tests were performed at a corporate firm, Chemgrit Cosmetics, over a 3 month period and results recorded at 1, 2, 4, 8, and 12 week intervals. Stability was compared to that of a control sample and both S1 and S2 were found to be stable at room temperature. The samples also showed no mutagenic effects when S. typhimurium strains TA98 and TA100 were used during the bioassay. A clinical study done by private firm Future Cosmetics concluded that both S1 and S2 were non-irritants with an irritant potential of -34.21% and - 37.90% for S1 and S2 respectively. S1 showed a large potential for the development of a skin even toner when incorporated into a formulation. The findings of the present study indicate that sample 1 has the potential to be used as effective and alternative treatments for the skin hyper-pigmentation disorder. The peatlands of the Highlands of Lesotho – A unique aquatic system under threat P.J. Du Preez a, L.R. Brown b, L. Seipethlo a a Department of Plant Sciences University of the Free State, South Africa b Applied Behavioural Ecology & Ecosystem Research Unit, University of South Africa, South Africa Numerous hill-slope seeps and valley bottom peatlands occur in the high-altitude headwaters of the Senqu River in Lesotho. These peatlands deliver important ecosystem services such as water retention, purification, and slow release of water as well as sustaining a unique plant and animal biodiversity. Due to the high altitudes (mostly above 2 000 m) a slow process of peat formation is taking place. On these peatlands a very unique plant community exists which supports several endemic plant species. A communal grazing system exists in the highlands of Lesotho and these peatlands are one of the main sources of pasture for the domestic stock. In order to describe the vegetation and species composition of these peatlands, sampling plots were randomly placed within the peatlands. All species present were recorded and their cover abundance assessed using the Braun–Blanquet cover abundance scale. Environmental data included slope, aspect, grazing, and erosion while the average height of the plants was also estimated. The data analysis was done by using TWINSPAN classification which was refined by using Braun–Blanquet procedures. An ordination of the data was 229 also done by using the CANOCO ordination techniques. The results reveal that the thurfur (elevated humps of peat) on the peatland supports a different plant species composition. Environmental factors such as wetland hydrology, drainage, erosion, and biotic impacts play important roles in the distribution of the wetland associated species. Several impacts are threatening to destroy these peatlands and drastic measures to conserve these unique ecosystems need to be put in place. Isolation and identification of compounds from an extract of Strophanthus speciosus (N. B. Ward. & Harv.) Reber., with emphasis on cardiac glycosides S. Emamzadeh-Yazdi a, A. Hussein b, G. Prinsloo c, Q. Kritzinger a a Department of Plant Science, University of Pretoria, Pretoria 0002, South Africa b Department of Chemistry of Medicinal Plants. National Research Centre, Dokki, Cairo, Egypt c Department of Agriculture and Animal Health, University of South Africa (UNISA), Florida Campus, Private Bag X6, Florida 1710, South Africa The discovery of active compounds in medicinal plants plays a strategic role in the phytochemical investigation of crude plant extracts. According to literature, plants containing cardiac glycosides (CG) show potential for the discovery of more effective new drugs in the treatment of viral infections. The aim of this study is to investigate the antiviral, antibacterial and cytotoxic activities of South African plants containing CG. Six plants were selected for the study of which none of them exhibited anti-herpes simplex virus activity, but only general toxicity. Chromatographic methods were used to identify the compounds and determine activity of the extracts on two bacteria, namely E. coli (Gramnegative) and E. faecalis (Gram-positive). The results showed promising activity of S. speciosus fruit extract against Grampositive bacteria. Isolation and purification of the ethanol extract of fresh fruit of S. speciosus was carried out by column chromatography and crystallization. Three compounds including a cardiac glycoside were isolated from S. speciosus. Structural determination of the pure compounds was based on physico-chemical properties and various spectral data analysis such as NMR was done in order to elucidate the structures of the compounds. The names of the compounds are yet to be confirmed. Optimizing germination of Coleonema album seeds O.O. Fajinmi, M.G. Kulkarni, J.F. Finnie, J. Van Staden Research Centre for Plant Growth and Development, School of Life Sciences, University of KwaZulu-Natal Pietermaritzburg, Private Bag X01, Scottsville 3209, South Africa C. album is a decorative shrub with dainty, small white flowers and a sweet, honey smell. It's an ideal garden plant 230 SAAB Conference Abstracts and an interesting specimen for floral arrangements. Apart from its horticultural value, a wide range of pharmacological activities such as antithrombotic, antiplatelet, vasolidatory, antibacterial, antifungal, antimycobacterial, antioxidant, antimicrobial, phytoalexin, and analgesic activities are attributed to C. album. Aromatherapy properties of C. album includes: antiseptic, deodorant, insecticide, sedative, restorative, diuretic and febrifuge activities. C. album is gaining popularity in South African herbal medicine as a tincture, known as Immunat, now marketed commercially. This has led to an increase in demand for C. album in the traditional medicinal markets. This will cause a threat to the wild population as a result of its intensive collection. Increasing demand of a medicinal plant such as C. album can only be met by developing effective propagation protocols. Unfortunately, there is very limited information available on the propagation requirements of this highly used medicinal plant. This necessitates research into the seed germination requirements and general physiological growth requirement in vitro and ex situ as a crucial step to ensure its survival. The influence of light, temperature, stratification (cold and warm), smoke-water, KAR1 (Karrakinolide 1), plant growth regulators (kinetin, GA3, KNO3, IAA, NAA and IBA) on seed germination of C. album was investigated in this study. Seeds incubated under cold temperatures of 10 °C and 15 °C showed favorable germination. No germination was recorded at high temperatures (20, 25, 30 and 35 °C) even after six weeks, unless they were transferred to cold conditions. Seeds exposed to continuous dark conditions showed equal responses as seeds exposed to alternating light conditions. Seeds with and without endosperm readily imbibed water which rules out physical dormancy and indicates physiological dormancy. Cold temperature conditions play a significant role in germination of C. album seeds. The application of salicylic acid to induce tolerance against C. austroafricana in E. grandis clone ZG14 L. Ferreira, S. Naidoo, A.A. Myburg Department of Genetics, University of Pretoria, Forestry and Agricultural Biotechnology Institute (FABI), Pretoria 0002, South Africa Eucalyptus is a globally important hardwood and fiber crop that provides high quality raw material for industry. One of the most important pathogens of this perennial is C. austroafricana, a fungus that is indigenous to South Africa and causes stem canker. This plant–pathogen interaction is used to investigate the activation of defense signaling pathways and the systemic induction of defense mechanisms in Eucalyptus. Salicylic acid regulates one such defense signaling pathway resulting in broad spectrum long-lasting resistance throughout the entire plant (systemic acquired resistance) that can be detected through the enhanced expression of particular marker genes such as pathogenesis-related protein 2 (EgPR2). The aim of this study is to determine whether the exogenous application of SA will lower the susceptibility of E. grandis ZG14 clones to C. austroafricana infection. The experimental procedure involved the treatment of the susceptible ZG14 clones with SA 24 h before inoculations. As controls, ZG14 clones treated with buffer and tolerant TAG5 clones were included in the experiment. In addition to measuring the lesion lengths of the plants, stem tissue surrounding the inoculation sites were harvested at three different time points. Following RNA isolation and purification from the harvested samples, gene expression profiling was conducted using reverse transcriptase quantitative PCR (RT-qPCR) to determine the quantitative expression of EgPR2. It is expected that a decrease in lesion size and accumulation of EgPR2 transcripts, indicative of the SA pathway and SAR, will be observed in the treated ZG14 clones before and after infection with the pathogen. This study will indicate whether the SA signaling pathway is important for defense against C. austroafricana. It will also qualify the use of SA to improve the tolerance of Eucalyptus against this fungal pathogen. The identification of desiccation-responsive heat-stable proteins from the fronds of the desiccation tolerant form of the resurrection fern Mohria caffrorum A.T. Gill, J.M. Farrant, M.S. Rafudeen Department of Molecular and Cell Biology, University of Cape Town, Private Bag X3, Rondebosch 7701, South Africa M. caffrorum (L.) Desv has the unusual characteristic in that it has a seasonal desiccation tolerance (DT), being tolerant in the dry and desiccation-sensitive (DS) in the rainy season. DT fronds acquire protective mechanisms during drying that are similar to those reported for resurrection angiosperms; however, there is limited information on mechanisms of vegetative desiccation tolerance in ferns. Preliminary one dimensional sodium dodecyl sulphate – polyacrylamide gel electrophoresis (1D SDS PAGE) showed that the DT form produced several new heat-stable proteins, which were not present in the DS form upon dehydration. The current study was undertaken to further characterize the heat-stable proteome of this species by use of 2-DGE in order to identify proteins that might play a protective role against dehydration. Three proteins were detected only in the dehydrated samples and these proteins were referred to as ‘de novo’ proteins. All three of these protein spots were identified by LC-MS/MS with high significance to known proteins. Two of the protein spots that were detected as ‘de novo’ were identified by LC-MS/MS as the chloroplast enzyme RuBisCo (ribulose-1,5-bisphosphate carboxylase/oxygenase) and the third ‘de novo’ protein was identified as an Oxidoreductase. Additionally, five protein spots that were up-regulated (paired t-test, P b 0.05) during drying were identified by LC-MS/MS. Only two of the five proteins were matched to known proteins. The two up-regulated proteins were identified as the antioxidant enzyme, superoxide dismutase (SOD) and the molecular chaperone, heat shock protein 70 (HSP70). The functional SAAB Conference Abstracts physiological and biochemical roles of these proteins as protectants in desiccation tolerance are being investigated. Identification of transposable elements in the pitch canker fungus, Fusarium circinatum J. Grové a, M.P.A. Coetzee b, E.T. Steenkamp a a Departments of Microbiology and Plant Pathology; b Genetics, Forestry and Agricultural Biotechnology Institute (FABI), University of Pretoria, South Africa F. circinatum is an economically important ascomycete that causes pitch canker disease of pine trees. Transposable elements (TEs) have been identified in some Fusarium species where they may comprise a significant portion of the genomic content. The aim of this study was to identify TEs in F. circinatum using the available genome sequence and to evaluate their potential contribution to inter- and intra-specific diversity in Fusarium. The de novo repeat-finding program, RepeatScout, was used together with BLAST to identify a set of 93 repetitive sequences in F. circinatum. Of these, eight were selected for further analyses as they displayed similarity to known TEs or the characteristic structural features associated with these elements. Six of the repetitive sequences represent retrotransposons and two nonautonomous DNA transposons. By making use of similarity searches with known proteins encoded by TEs, a further 58 contig regions with enzyme homology were identified in the F. circinatum genome, although only two harbored open reading frames that were not interrupted by nonsense and frame-shift substitutions. Overall it thus seems that the putative TEs in F. circinatum are fragmented and non-functional, which suggests that these elements are in the degradation phase of their lifecycle within the genome. Additionally, at least one of the eight putative TEs in F. circinatum appeared to be present in high copy numbers in the closely related Fusarium verticillioides and Fusarium fujikuroi, but not in the more distantly related members of this genus. PCR-based assays indicated that one of the putative DNA transposons varied considerably in distribution and density among different isolates of each of F. circinatum and F. verticillioides. These data thus suggests that TEs represent a significant source of intra- and well as inter-specific variability and holds potential for use in epidemiological studies of F. circinatum and its close relatives. Invasive Crotalaria agatiflora Schweinf. – Ecology and distribution in South Africa T.P. Jaca Early Detection and Rapid Response Programme (EDRR), South African National Biodiversity Institute, Private Bag X101, Pretoria 0001, South Africa C. agatiflora (canary bird bush) is an evergreen shrub or small tree up to 1-10 m tall; mostly glabrous, with young shoots softly 231 hairy. The leaves are grayish-green, 3-foliolate; leaflets on a short stalk (petiole), petiole mostly longer than leaflets, glabrous to densely hairy. Flowers are lemon-yellow or greenish-yellow, with a projecting greenish or purple beak in many-flowered racemes to 400 mm long. Canary bird bush is native to Tropical East Africa and North-East Africa (Tanzania and Kenya) and was probably introduced in South Africa as an ornamental. The earliest record of this species in South Africa is of a specimen in the Pretoria National Herbarium collected in Johannesburg area at the Railway Horticulture Garden in 1921 and the earliest record of its establishment in the wild is from Rustenburg to Brits. The species is a proposed category 1a in NEMBA regulation. Although no studies have focused on its effects on natural ecosystems canary bird bush may affect the ecology of invaded areas in several ways, for example the enhancement of nitrogen levels in the soil. It threatens watercourses in grassland and savanna biomes; potentially invasive on forest margins and also occupying cleared grassy areas. The distribution of canary bird bush in South Africa was mapped using records from South African Plant Invaders Atlas database, herbarium records and field records. Results indicated that canary bird bush distribution is mostly along road sides and the species has spread into natural areas for example, Colbyn wetland, Wonderboom Nature Reserve and Faerie Glen Nature Reserve. A guide to plant families of southern Africa M. Koekemoer a , H.M. Steyn a, S.P. Bester a,b a National Herbarium, South African National Biodiversity Institute, Private Bag X101, Pretoria 0001, South Africa b School of Environmental Sciences and Development, NorthWest University, Private Bag X6001, Potchefstroom 2520, South Africa Knowledge of plant families allows one to place unknown plants into broad categories. Once the familial identity is established one can focus on the smaller divisions of genera and eventually species. Southern Africa has a total of 225 plant families. A project to illustrate the diagnostic characteristics of the 51 largest families is currently underway – these families represent ± 90% of the total flowering plants for this area. The publication will assist scholars, students, amateurs and professionals to identify these plant families. The aim is to educate the public on the beauty and diversity of our fascinating flora and to expand the base of knowledge of the plant families. If a person can attach a name to a plant, it immediately has more meaning and scientific value, fostering appreciation. It is then easier to communicate about the plant and to find more related information on it. The information presented is uncomplicated and designed for users at different levels of expertise. The focus will be on having more images than text. This product will make the complex process of classification and identification more ‘friendly’ and understandable to scientists and non-scientists alike. 232 SAAB Conference Abstracts Be warned! Invasive succulent, Furcraea foetida (Mauritius hemp) on the loose! R. Lalla Early Detection and Rapid Response Programme (EDRR), South African National Biodiversity Institute (SANBI), Private Bag X101, Pretoria 0001, South Africa F. foetida (= Furcraea gigantea) is a succulent, with swordshaped, light green leaves arranged in a basal rosette. Belonging to the Agavaceae family, this species was widely cultivated for fiber in the past. However, in more recent years F. foetida has been labeled as a “garden escapee” in some countries, as its invasive potential is being recognized. F. foetida thrives in cliff-like habitats, and is tolerant of very shallow soil. This species reproduces prolifically, with approximately 1250 bulbils (vegetative reproductive structures) produced per flowering stalk. Carpets of offspring which result from the mass production of bulbils, transforms into impenetrable thickets over time. F. foetida poses a threat to indigenous vegetation, and its invasive potential must be investigated. In 2009, F. foetida was proposed to the EDRR programme as an EMERGING Invasive Alien Plant (IAP) in KZN, and at the time, not much was known about the distribution of this species in the country. Efforts of the EDRR programme have led to a significant increase in the number of known F. foetida localities in KZN, and in other provinces in South Africa. This poster highlights the biology and ecology of F. foetida, identifying features of the species, and current known South African localities, as well as challenges that have been experienced in dealing with this species. Single nucleotide polymorphism (SNP) diversity in xylem and leaf expressed cellulose synthase genes of Eucalyptus grandis B. Lombard a , C. Hefer a,b, A. Van der Merwe a, E. Mizrachi a, A. A. Myburg a a Department of Genetics, Forestry and Agricultural Biotechnology Institute (FABI), University of Pretoria, Pretoria 0002, South Africa b Bioinformatics and Computational Biology Unit, Department of Biochemistry, University of Pretoria, Pretoria 0002, South Africa E. grandis is a commercially important tree species with excellent wood properties for pulp and paper production. Recent availability of the E. grandis genome sequence provides possibilities for tree improvement by means of marker-assisted breeding. Genetic variant discovery is important for identifying links between genotypic and phenotypic variations in tree populations. This study focused on single nucleotide polymorphism (SNP) diversity in xylem and leaf expressed cellulose synthase (CesA) genes of E. grandis. Illumina mRNA-seq reads from immature xylem and young leaf tissues were generated from 30 E. grandis individuals representing 28 families in a breeding population. The RNA sequences were aligned to the E. grandis reference genome using TopHat software and visualized using SAMtools. Data for eleven characterized Eucalyptus CesA genes was extracted and analyzed to determine the distribution of SNPs in primary and secondary cell wall related CesA genes. Coverage up to 4160 × as well as minor allele frequency (MAF) up to 0.29 were detected for the CesA genes. SNPs were only called with a minimum SNP quality of 60, minimum coverage of 8 × at the SNP position and minor allele coverage of 4 ×. Synonymous or non-synonymous amino acid changes associated with coding SNPs were recorded. An interesting finding is that it appears that there is far greater diversity of alleles expressed in primary cell wall related genes than secondary cell wall related genes of the same thirty individuals. It was also found that SNP density in primary and secondary cell wall related CesA genes ranged from 0.6 to 13.3 and 1.2 to 10.3 SNPs per 100 bp. Methods from this study will be applied to the rest of the transcriptome sequence to describe genetic diversity in protein coding genes of this breeding population, as well as for the development of SNP markers for future molecular breeding efforts. South Africa's succulents under threat L.E. Makwarela, J.E. Victor National Herbarium, South African National Biodiversity Institute, Private Bag X101, Pretoria 0001, South Africa The Red List of South Africa is a useful tool for assessing conservation priorities, and furthermore, provides insight into areas where information is lacking and future research thrusts are needed. Succulents are prone to threats from overharvesting, and also have an unusually high number of species classified as Data Deficient due to the lack of information. Our analyses show that in South Africa, the Asphodelaceae are the most threatened of the succulent plant families and are therefore most in need of conservation attention. Mesembryanthemaceae have the highest proportion of (and highest number of) Data Deficient species and are therefore most in need of future research efforts. It is concluded that succulents are particularly vulnerable to threats because of their relatively slow growth compared with other herbaceous plants, coupled with their desirability in the horticultural industry. Variations in the epidermal structure of Acacia tortilis Hayne. grown in different climatic conditions P.S. Mashile, R.B. Bhat, M.P. Tshisikhawe Department of Botany, University of Venda, Thohoyandou 0950, South Africa Leaf epidermal structure of A. tortilis from nine different sites was investigated. The leaves of A. tortilis were found to be hypostomatic. The epidermal cell showed a polygonal structure with anticlinal walls either straight or curved. Trichomes were non- SAAB Conference Abstracts glandular, unicellular and conical in shape. Paracytic, anisocytic and stoma with a single subsidiary cell were the stomatal types observed. The frequency of epidermal cells was higher as compared to that of guard cells. The stomatal index and frequency of stomata and epidermal cells were also compared and recorded. Variations in the epidermal structure of leaves and morphological structure of the plant from different habitats were also recorded. Further anatomical investigations are in progress. Ecological, morphological and ethnobotanical assessment of Acacia karroo and Acacia tortilis at Nylsvley Nature Reserve, Limpopo Province, South Africa P. Masiagwala, R.B. Bhat, M.H. Ligavha-Mbelengwa Department of Botany, University of Venda, Thohoyandou 0950, South Africa The genus Acacia is the most significant species of the family Fabaceae. This family was first described by Linnaeus in 1773. A. karroo also known as the sweet thorn, is a species of Acacia, native to southern Africa from southern Angola east to Mozambique, and south to South Africa. This species is widespread in clayey water-logged areas of the Nylsvley Nature Reserve. It is a pioneer species and generally invades disturbed habitats. It grows in a range of soils from sandy to heavy clayey ones. In Nylsvley Nature Reserve it occurs in a few numbers in sandy soils and is common in fertile clayey waterlogged areas. A. karroo is often associated with symbiotic Rhizobium sp. that fixes nitrogen. It is therefore important in the nutrient dynamics of the nature reserve. This plant is of economic importance as fodder for the animals and it has a number of medicinal and other commercial values. A. tortilis is drought resistant, can tolerate strong salinity and seasonal waterlogging and generally forms open forests in pure stands or mixed stands in these dry lands. It is also adapted to an environment with little and unreliable rainfall, and under these constraints it is as well adapted to anthropogenic pressures as it is the sole source of animal fodder, firewood and shelter for nomads. Combined pressures and their variation are reflected in its growth forms. The aim of the project was to investigate the ecological, morphological and ethnobotanical assessment of A. karroo and A. tortilis at Nysvley Nature Reserve, Limpopo province. Data were collected from different habitats of the Nysvley Nature Reserve such as water logged, sandy and loamy soil areas. Canopy diameter was measured by using the measuring tape, tree height was taken using the height rod, and the trunk diameter by using diameter tape. Morphological variations have been observed within species growing under different habitats. Further ecological and ethnobotanical investigations are in progress. Medicinal plants of the Blouberg Mountain, Limpopo Province, South Africa K.M. Mathibela, B.A. Egan, H.J. Du Plessis, M.J. Potgieter 233 University of Limpopo, Department of Biodiversity, Private Bag X1106, Sovenga 0727, South Africa Blouberg Mountain, Limpopo, is a center of plant endemism upon which a large rural community depends for numerous natural resources. The mountain itself enjoys no formal protection (Blouberg and Maleboch Reserves protect only a small area on the northern slopes) and few studies have examined the extent to which it provides such services. This study investigates the medicinal plant species used by traditional healers on the mountain in terms of species collected, manner of harvesting and where they are collected. Traditional healers from villages surrounding the mountain were interviewed during questionnaire surveys and participant observation walks. Data was gathered on general and personal information, species collected, collection methods, patient consultation, legislation and conservation. Healers were also interviewed in their consultation rooms. Plant specimens were collected and identified and the conservation status of the species was investigated. This was compared to the healers' perceptions of the rarity of the plants. Forty one species of plants were collected from the mountain and 37 species were noted from consulting rooms. None of the healers interviewed had any knowledge of the most important plant conservation legislation in the province, or of the existence of a Red Data List for plants. Most interviewees (71%) however, felt positive about the proposal of harvesting restrictions. The medicinal plants W. salutaris, H. hemerocallidea and Boophane disticha are mentioned in the Red Data List (2011) as endangered and declining but are not perceived as rare or declining by the healers. Conversely, a number of least concern plants are seen as rare by the healers. Conservation recommendations were developed. The use of GIS in documenting medicinal plants of Blouberg Mountain, Limpopo Province, South Africa K.M. Mathibela, B.A. Egan, H.J. Du Plessis, M.J. Potgieter University of Limpopo, Department of Biodiversity, Private Bag X1106, Sovenga 0727, South Africa A Geographic Information System (GIS) is a tool that combines statistics with geographic locations to create informative maps. The use of GIS technology to document the indigenous knowledge of an area has become more prevalent, however, the analysis of medicinal plant collection pathways (tracks) using this method is ground breaking. This study examined the utility of a readily available and easily implemented application of Geographic Information Systems for describing and analyzing the collection tracks of traditional healers with respect to where the most important collecting sites are located. For the first time, healers' pathways were digitized, georeferenced and linked to other information on the medicinal plants around Blouberg Mountain, making this information easier to analyze and access. Sixteen of the most used collection tracks were investigated and co-ordinates taken for the 234 SAAB Conference Abstracts beginning of each track, plant collection per track, change of a track and ending of each track. Forty one medicinal plant species were documented from the 16 tracks surveyed. The collection tracks were mapped and overlaid with topographic and demographic information as well as vegetation types of the Blouberg Mountain. Areas of high use or areas impacting on sensitive vegetation types are clearly evident from the map and can be targeted for immediate remedial action. This information, particularly that regarding species of medicinal plants utilized and most impacted areas of the mountain, will be invaluable to Limpopo conservation officials who are in the process of implementing a conservation plan for the province. Biodiversity of Ceratocystis species infecting wounds on elephant-damaged trees in the Kruger National Park M. Mbenoun a , M.J. Wingfield a, B.A.D. Begoude b, B.D. Wingfield a , J. Roux a a DST/NRF Centre of Excellence in Tree Health Biotechnology (CTHB), Department of Microbiology and Plant Pathology, Forestry and Agricultural Biotechnology Institute (FABI), Private Bag X20, University of Pretoria, Hatfield 0028, South Africa b Institute of Agricultural Research for Development (IRAD), Nkolbisson B.P. 2067, Yaounde, Cameroon It is now widely accepted that fungi represent a major component of the diversity of life on Earth. Their critical role in creating and maintaining biodiversity and in the functioning of terrestrial ecosystems is also well established. Yet, our knowledge of fungal biodiversity remains very limited, the more so when considering the community of micro-fungi in natural ecosystems in Africa. The genus Ceratocystis includes important pathogens of mostly woody plants. These micro-fungi exist in symbiotic associations with insects, relying on morphological and semiochemical adaptations to facilitate these interactions. Ceratocystis spp. have also received increasing attention globally because of the emergence of serious diseases that they cause in commercial forestry plantations and native forests. Studies in South Africa have suggested the existence of a substantial undiscovered biodiversity of Ceratocystis species in natural ecosystems in the country. In this study we investigated the occurrence and diversity of Ceratocystis species on elephant-induced tree wounds on trees in the Kruger National Park. Surveys conducted in the park between 2009 and 2010 resulted in the collection of 298 Ceratocystis isolates, obtained from 25 tree species in 10 plant families. Isolates were characterized using DNA multigene phylogenies and diversity indices and estimators were calculated for the entire park as well as for various ecozones within the park. An unexpectedly high diversity of Ceratocystis was discovered, both at genetic and species levels. We recovered 9 species in 3 Ceratocystis lineages and at least 50 distinct haplotypes. Four of the species represent previously unknown taxa. Although there were some differences in species abundance and occurrence between the various ecozones, similarity indices did not show significant departure from complete evenness. This is an indication that factors other than the host species composition determine the distribution and prevalence of these fungi in natural ecosystems. Grafting method to improve vine production of orange fleshed sweet potato cultivar ‘Resisto’ under water stressed conditions H.C. Mihiretu a, E. Du Toit a, J.M. Steyn a, S.M. Laurie b a Department of Plant Production and Soil Science, University of Pretoria, Pretoria 0002, South Africa b ARC-Roodeplaat, Vegetable and Ornamental Plant Institute, Private Bag X293, Pretoria 0001, South Africa Orange fleshed sweet potato (Ipomoea batatus L.) (OFSP) is a rich and cheap source of pro-vitamin A ß-carotene. Vitamin A deficiency, which leads to night blindness and infant mortality, can be combated by dietary intervention using OFSP. Shortage of planting material caused by a prolonged dry season is one of the main constraints of OFSP production in Africa. Therefore, this research was conducted to assess the vine production potential of drought sensitive OFSP cv. ‘Resisto’ (R) grafted onto drought tolerant creamy fleshed sweet potato cvs. ‘Tanzania’ (T) and ‘Zapalo’ (Z) under different water stress conditions. Histological analysis conducted to determine the graft compatibility of scion (R) and root stock (T and Z) revealed differentiation of a new vascular cambium on the 10th day after grafting (DAG). By the 23rd DAG the presence of newly restored vascular tissue was observed. A two factor field experiment was conducted to compare three planting materials (‘Resisto cutting’ (R), ‘Resisto × Tanzania’ (RT) and ‘Resisto × Zapalo’ (RZ)) at three deficit irrigation levels (30%, 60% and 100% of measured deficit refilled). RT gave significantly (α b 5%) higher above-ground biomass yield (14.1 tha - 1) at 30% deficit irrigation. Similarly, RT at 30% deficit irrigation showed significantly (α b 5%) higher water use efficiency (WUE) for above-ground biomass (179.1 kg ha - 1 mm - 1) and cutting number (7091 cuttings ha - 1 mm - 1). Application of drought sensitivity and tolerance indices on vine yield showed that among the three planting materials used, RT was the most productive planting material at 30% deficit irrigation level. Generally, grafting improved vine productivity of OFSP cultivars under low water conditions. This study introduced the use of grafting techniques as a novel method to maintain OFSP vine over prolonged drought conditions. Comparative anatomy of the galls and equivalent healthy plant organs in Terminalia sericea (Combretaceae) T.E. Mphephu, L.I. Ramovha Department of Botany, University of Venda, Private Bag X5050, Thohoyandou 0950, South Africa Various types of galls and the equivalent healthy plant organs of T. sericea were collected from different areas of SAAB Conference Abstracts Limpopo. Leaf, young stem, round axial and long axial galls were mostly recorded in seedlings and young trees whereas flower and seed galls were prominent on adults trees. Collected samples were fixed in 75% FAA. Sections were prepared by hand and studied under light microscope. Digital images were taken by MR5 axio vision microscope for analysis. The main objective of the study was to establish the cause of the galls and resultant changes induced by the gall-forming agent to the associated plant tissues. Larvae of various wasps and moth species were found in long axial galls. Flower and seed galls were formed by fungi. Unidentified insects larvae were associated with Young stem, leaf and round axial galls. Comparative anatomical examination of the galls and healthy organs showed the proliferation in the former of new parenchyma tissue around vascular bundles and the pith. Galls on stems are characterized by deformed and poorly developed secondary xylem with increased medullary rays. The results indicate that galls develop in response to the formation of new, mainly parenchymatous tissue resulting in local swelling of the particular plant organ. Gall-induced parenchymatous tissues are the main food source for the insect larvae inhabiting the galls. A survey of invasive alien plants and their current distribution at Wonderboom Nature Reserve B.T. Mthembu, T.P. Jaca Early Detection and Rapid Response Programme (EDRR), South African National Biodiversity Institute, Private Bag X101, Pretoria 0001, South Africa Alien plant invasion in South Africa poses a major threat to the biodiversity and functioning of ecosystems and the services they provide. Nature reserves in the world are threatened by invasive alien plants (IAP's) and South Africa is not an exception. The invasion of nature reserves by alien invasive plants results in ecological succession, where the new alien invaders establish themselves and outcompete the native species. The most cost effective way to manage IAP's is to prevent invasions before they even occur, or controlling them at the early stages of invasion. An inventory of IAP and their distribution inside the reserve are significant in understanding their control methods and threat to biodiversity. The aim of this study was to identify and determine the distribution of IAP in the Wonderboom nature reserve. This information will be used by the reserve managers to develop management plans for targeted species in the reserve. Stratified random sampling methods were used to determine the extent of IAP's distribution inside the reserve. This study present preliminary findings of an initial survey of IAP's inside Wonderboom Nature Reserve. A total of 17 IAP's were identified, and their distribution was mapped using geographic information system. 235 An inventory of indigenous medicinal plants used in the treatment of sexually transmitted infections in Vhembe District Municipality, Limpopo Province, South Africa T.M. Mulaudzi, N.A. Masevhe Department of Botany, School of Mathematics and Natural Sciences, University of Venda, Thohoyandou 0950, South Africa Ethnobotanical survey was conducted to document medicinal plant species used in the treatment of sexually transmitted infections in Vhembe District Municipality, Limpopo Province, South Africa. Twenty one traditional healers were interviewed using structured questionnaires. Topics discussed during the interviews were symptoms of the disease, local plant names, plant parts used, mode of preparation, route of administration, dosage etc. A total of 45 plant species belonging to 21 different families were reported as being used for the treatment of sexually transmitted infections such as syphillis, gonorrhea and herpes. The most common used families were the Myrtaceae and Apocynaceae (9.4%) and the rest contributed 2.3% only. The most frequently used plant parts were roots (68%), stem bark (17%) and leaves (15%). Preferred methods of preparing the remedy were infusion and decoction, and about 91% of preparations were administered orally in variable doses until the patient was cured. Forty five medicinal plant species recorded in this study were also used by traditional healers to treat other ailments and this may validate their efficacy. Further studies are ongoing in order to establish their antimicrobial activity and to isolate the active chemical components. Hypericum pseudohenryi – An invasive alien plant in the KZN Drakensberg and KZN Midlands I. Nänni Early Detection and Rapid Response Programme (EDRR – funded by Working for Water), South African National Biodiversity Institute, P.O. Box 52099, Berea Road, Durban 4007, South Africa An alien species of Hypericum (Clusiaceae), recently identified as H. pseudohenryi, is invading stream beds and undisturbed grassland habitats in the KZN Drakensberg and KZN Midlands. Preliminary investigations and risk assessment suggest that this species poses a threat to indigenous biodiversity by out-competing indigenous species, hybridizing with local Hypericum species and affecting stream flow dynamics in the Drakensberg catchment areas. An initial survey of the KZN Mistbelt revealed that naturalized populations of Hypericum pseudohenryi are more extensive and widespread than originally thought. These concerns justify the decision to fund clearing efforts in KwaZulu-Natal while collecting information on reproductive strategy and response to herbicides. 236 SAAB Conference Abstracts Surveillance of potential emerging wetland alien invaders M.M. Nxumalo a, H.J.N. Sithole a, E. Van Wyk b a Early Detection and Rapid Response Programme (EDRR – funded by Working for Water) South African National Biodiversity Institute, P.O. Box 52099, Berea Road, Durban 4007, South Africa b Private Bag X7, Newlands 7735, Cape Town, South Africa Hydromorphic and aquatic invasive alien plants pose a great threat to South Africa's wetlands. They form dense stands blocking the movement of water and aquatic fauna, cause sedimentation and outcompete indigenous plants. Their ability to reproduce in several ways: vegetatively, sexually, through tubers and turions gives them a competitive advantage over indigenous plants. Tubers and turions have an ability to survive adverse conditions for long period. Six potential wetland invaders are currently investigated by the Early Detection and Rapid Response (EDRR) Programme. Four of them are listed as category 1a on the proposed NEMBA regulation. Hydrilla verticillata is a completely submerged aquatic plant, Hydrocleys nymphoides floats in water, Iris pseudacorus, and Lythrium salicaria are rooted in water but emergent above the surface. The remaining two species are newly detected invaders and do not yet have a legal status as invaders. Sagittaria platyphylla has two forms: emergent and submerged, Spartina alterniflora have an ability to hybridize with indigenous grasses. The varied growth forms and behavior of these plants make it difficult to generalize about their management. The poster highlights the outcomes of the work in progress such as mapping, assessment of ecological impacts and current levels of infestation. Reports of new sightings will add value to the work done. Hence the purpose of the poster is to advise the public about possible dangers, and to call for more sightings of these species. Indigenous medicinal plants used by traditional healers in the stimulation of appetite of HIV/Aids related patients in Vhembe District Municipality, Limpopo Province, South Africa K.R. Phalandwa, M.P. Tshisikhawe Department of Botany, University of Venda, Thohoyandou 0950, South Africa The study investigated indigenous medicinal plants used by traditional healers in the stimulation of appetite in HIV/AIDS related patients in Vhembe District Municipality. In this study Knowledge of traditional healers was used in order to collect data through structured interviews. Questionnaires collected data on causes, symptoms and the treatment of lack of appetite. The preparation techniques and dosages of medicinal plants were also recorded. Thirty-five plant species were recorded to be used in the stimulation of appetite. The plants were identified and information about their other medicinal uses was also investigated. The large amount of information on medicinal plants used in the treatment of lack of appetite suggests the importance of traditional knowledge in appetite stimulants. Characterization of wetland systems and zones based on vegetation composition on the Maputaland Coastal Plain L. Pretorius a, L. Brown a, G. Bredenkamp b, T. Mostert c a Applied Behavioural Ecology and Ecosystem Research Unit, University of Pretoria, South Africa b Department of Plant Science, University of Pretoria, Pretoria, South Africa c Department Botany, University of Zululand, KwaDlangezwa, South Africa The Maputaland Coastal Plain (MCP), located in northeastern KwaZulu-Natal, is dominated by cover sands and is therefore regarded a sandy coastal aquifer. According to the Department of Water Affairs' wetland delineation and manual delineating wetlands on these aquifers is complex due to problematic wetland soils. It is believed that an understanding of the vegetation composition of wetlands on the MCP can aid wetland delineators. The aim of this study was to classify and describe the vegetation of the different zones of the various wetland systems to determine if differences in vegetation could assist in delineation and understanding of these complex ecosystems. Thirteen wetlands that can be grouped into four wetland systems located between Tembe Elephant Park in the west and Kosi-Bay in the east were surveyed. In each wetland the permanently wet, the seasonally wet, and the terrestrial zones were sampled. - 1A total of 73 relevés of 4 m 2 size were placed using the modified Braun– Blanquet cover abundance scale. The relevés were captured into Turboveg for Windows 1.97 and imported into JUICE 7.0. A modified TWINSPAN was performed to determine a first approximation of the vegetation. A phytosociological table was compiled. Synoptic tables and dendrograms were used to aid in the identification of vegetation clusters. Preliminary results identify 11 vegetation communities which are strongly related to the wetland types as defined by the hydrological regime, geohydromorphological setting, and substrate type. Variation of the vegetation composition within the specific wetlands gives a strong indication of zoning, which is related to the wetness gradient within each system. These results contribute to the understanding of the relationship between vegetation and environmental drivers within wetland systems, and can be used to aid wetland delineation on the MCP. Biological activity of methyl ursolate from Funtumia africana (Apocynaceae) leaf extracts T.E. Ramadwa a, E.E. Elgorashi b, J.N. Eloff a a Phytomedicine Programme, Department of Paraclinical Sciences, Faculty of Veterinary Sciences, University of Pretoria, Private Bag X04, Onderstepoort 0110, South Africa SAAB Conference Abstracts b Currently ARC-Onderstepoort Veterinary Institute, Private Bag X05, Onderstepoort 0110, South Africa F. africana is traditionally used across Africa to treat diverse ailments including infectious diseases, burns and others. The aim of the study was to evaluate the antibacterial, antifungal, and anti-inflammatory activities of the acetone extract of F. africana leaves, together with its fractions (Hexane, chloroform, 30% in methanol, butanol, and water) and the isolated bioactive compound. The antimicrobial activity was evaluated using serial microdilution assay and bioautography. The antiinflammatory activity was determined using both cyclooxygenase (COX-1) and cylooxygenase (COX-2) enzymes. The four nosocomial bacterial pathogens tested were E. coli, E. faecalis, P. aeruginosa and S. aureus. The fungal test organisms used were A. fumigatus, C. neoformans, C. albicans, F. oxysporum, Penicillium janthinellum and Rhizoctonia solani. The crude extract of F. africana had minimal inhibitory concentration (MIC) as low as 0.08 mg/ml against both bacterial and fungal test organisms. On bioautography, F. africana crude extract had consistent antibacterial activity against all the bacteria with clear zones of inhibition on TLC bioautograms. The chloroform fraction had an MIC as low as 20 μg/ml against P. aeruginosa. The crude extract together with hexane and chloroform fractions had moderate activity against both COX1 and COX-2. The chloroform fraction was more active than the crude extract (59.7 ± 1.4%) with an inhibition of 68.2 ± 6.6% against COX-1. One antimicrobial compound was isolated from chloroform fraction using column chromatography and chemically characterized as methyl ursolate using NMR and Mass Spetroscopy. MU had an MIC as low as 63 μg/ml against F. oxysporum. Although MU was less active against all the bacteria with MIC values N250 μg/ml, the MIC value of chloroform fraction (20 μg/ml) was more than hundred times lower than the MIC of MU. This provides strong evidence of synergistic activities and may be a model to investigate how synergism contributes to antimicrobial activities. An inventory of indigenous medicinal plants used in the treatment of thrush and related infections in Vhembe District Municipality, Limpopo Province, South Africa S. Ramulifho, N.A. Masevhe Department of Botany, School of Mathematics and Natural Sciences, University of Venda, Thohoyandou 0950, South Africa Ethnobotanical survey was conducted to document indigenous medicinal plants used in the treatment of thrush in Vhembe District Municipality, Limpopo Province, South Africa. Twenty one traditional healers were interviewed using structured questionnaires. Some of the topics discussed with the traditional healers included symptoms of the disease, local plant names, plant parts used, mode of preparation, route of administration and dosage. A total of 55 plant species belonging to 23 different families were recorded. The most common 237 used families were Celestraceae and Rutaceae (11.4%) and the rest of the families contributed (2.1%) each. Plant parts frequently used were roots (62%), then followed by stem bark (27%), leaves (9%) and seeds (2%). The most common preparations were infusion and decoction. Oral application had the highest mode of administration (83.7%) while the combination of both oral and external applications was (12.5%). A total of 55 plant species used to treat thrush by traditional healers support the importance which the medicinal plants have in the primary health care of the rural people. These plant species were also found to be used in other parts of the world for treating a variety of diseases and further investigation is going on to determine their antimicrobial activity. SNP-based genetic linkage maps of cassava (Manihot esculenta) S.M. Reynolds a, M.M. Van Dyk a, M. Luo b, E. Okogbenin c, L.A. Becerra Lopez-Lavalle d, M. Ferguson e, A.A. Myburg a, P. Rabinowicz f a Department of Genetics – Forestry and Agricultural Biotechnology Institute (FABI), University of Pretoria, Pretoria 0002, South Africa b University of California, Davis CA, USA c National Root Crops Research Institute, Nigeria d International Center for Tropical Agriculture (CIAT), Colombia e International Institute for Tropical Agriculture (IITA), Nairobi, Kenya f Institute for Genome Sciences, University of Maryland School of Medicine, Baltimore, MD, USA Cassava is a highly heterozygous staple crop grown in the tropical regions of Africa, Asia and Latin America. To date, six genetic linkage maps have been published for cassava, using mainly AFLP, RFLP and SSR markers. However, to our knowledge no genetic maps incorporating SNP markers have been reported. Our aim was to construct genetic linkage maps for a cassava mapping pedigree using SNP markers developed from expressed gene sequences and BAC-end sequences. Three custom designed GoldenGate Genotyping (Illumina) kits were used to genotype the CTS-1A drought tolerance mapping population (235 progeny) resulting from a cross between MCOL1734 (female, drought tolerant) and VEN77 (male, drought susceptible). This population was grown in a CIAT field in Columbia as part of a collaborative project funded by the Generation Challenge Program (GCP). Both parents and 226 progeny were successfully genotyped with 718 SNP markers, of which 556 (68%) were polymorphic in the parents. GenTrain scores ranged from 0.39-0.97, with an average of 0.82. JoinMap (Kyazma) was used to construct linkage maps consisting of 430 SNP markers distributed in 19 linkage groups (LOD 4.0), each one containing between 3 and 63 markers and spanning 2.9-162.7 cM (Kosambi) in length. The total map length was 1219 cM with an average marker interval 238 SAAB Conference Abstracts of 2.94 cM. The coverage and resolution of these maps will be increased by the addition of 124 SSR markers. In addition, using the same SNP markers, genome-wide SNP diversity patterns will be assessed using 217 cassava germplasm accessions from Africa and Latin America. These maps will also be useful for future QTL studies of drought tolerance, a trait that is expected to segregate in this population. Expression analysis of two genes during three different wheat-Puccinia interactions using qPCR J.J. Scholtz, B. Visser Department Plant Sciences, University of the Free State, P.O. Box 339, Bloemfontein 9300, South Africa Two unidentified genes that could play a role during the defense response of wheat (T. aestivum) following infection by Puccinia triticina were recently cloned. Real-time PCR (qPCR) was used to evaluate the expression levels of both genes during infection of wheat by P. triticina, P. graminis f.sp. tritici and Puccinia striiformis respectively. Normalization of qPCR data requires stable reference genes under all environmental and physiological circumstances. Since limited information on reference genes during wheat–rust interactions was available, the stability of six candidate reference genes during the three respective interactions was determined. The geometric means of multiple reference genes most suitable for normalization for each interaction were identified using the geNorm Plus algorithm. For P. triticina infected wheat, the 18s rRNA and RLI genes showed the best stability and for P. striiformis infected wheat, CDC and RLI were the most stable combination. P. graminis f.sp. tritici infected wheat required three reference genes, namely CDC, 18S rRNA and GAPDH. Using the appropriate reference genes, the differential expression of the cloned genes was confirmed. Catharanthus roseus: Extraordinary Bapedi medicinal herb for gonorrhea S.S. Semenya a, L.J.C. Erasmus b, M.J. Potgieter a a Departments of Biodiversity and bPhysiology and Environmental Health, School of Molecular and Life Sciences, University of Limpopo, Private Bag X1106, Sovenga 0727, South Africa C. roseus is a widespread exotic perennial herb, with numerous variations in flower color. It is world renowned for its contribution to the development of specific anti-cancer drugs, as well as its hypoglycaemic activity. Existing South African findings indicated poor anti-STI activity from leaf extracts. However, Bapedi traditional healers exclusively utilize root extracts to treat gonorrhea. Support for this use is found in the vernacular name for C. roseus; lepolomo le pinki la drop, which alludes to the presence of an abnormal urethral discharge in the symptomatic presentation of gonorrhea. Current uses and research, focuses predominantly on aerial parts of this species. The unique Bapedi custom to exclusively use roots warrants further investigation to validate its efficacy in the treatment of gonorrhea Expression and characterisation of EgrSND2, a Eucalyptus grandis transcription factor potentially involved in secondary cell wall regulation P. Singh a,b , S.G. Hussey a,b, C. Maritz-Olivier a, E. Mizrachi a,b, A.A. Myburg a,b a Department of Genetics, bForestry and Agricultural Biotechnology Institute (FABI), University of Pretoria, Pretoria 0002, South Africa The transcriptional regulation of secondary cell wall (SCW) biosynthesis has been studied extensively in A. thaliana, revealing a hierarchy of predominantly NAC and MYB transcription factors that regulate the formation of cellulose, hemicellulose and lignin, the three main SCW biopolymers. AtMYB103, AtSND2 and AtSND3 transcription factors have been found to regulate SCW-associated cellulose synthase (CesA) genes in A. thaliana. Cellulose fibers from E. grandis wood are one of the most commonly used short fiber sources for pulpwood in the paper industry. Our understanding of the regulation of cellulose biosynthesis is vital to the pulping industry and will have great economic impact. Currently, the transcriptional network regulating SCW biosynthesis in E. grandis is poorly understood. We aimed to identify and clone an E. grandis ortholog of AtSND2, heterologously express the protein and evaluate its promoter binding specificity. The EgrSND2 coding sequence was cloned into the pET160 vector and transformed into the E. coli BL21Star strain, which was used to optimize expression using temperature, time and inducer concentration parameters. We obtained exclusively insoluble protein when expression was induced at temperatures of 25 °C, 30 °C and 37 °C and IPTG concentrations of 0.1 mM, 0.5 mM and 1 mM over 24 h. Hence, we adopted a protein unfolding/ refolding approach by purifying inclusion bodies and denaturing and refolding the heterologous protein. Soluble protein and candidate E. grandis gene promoter fragments will be analyzed by electrophoretic mobility shift assays to identify direct targets of EgrSND2. A study of a population of a Thamnochortus species at the Sundays River, Eastern Cape S. Situngu, R.A. Lubke Department of Botany, Rhodes University, Grahamstown 6140, South Africa A population of a Thamnochortus species has been discovered in the Sundays River mouth region. There were many species planted in the area by the Department of Forestry to SAAB Conference Abstracts stabilize the mobile dune field but Thamnochortus species were never used in the stabilization programme. The population of plants seemed to be indigenous to the area and is confined to the limestone cliffs along the old and present river valley away from the stabilization site. Thamnochortus species of the Western Cape growing on alkali sands and limestone were studied and compared with the population at the Sundays River region. A multivariate analysis was performed on both quantitative and qualitative characters to test whether the Sundays River species was different from the Western Cape species. The Sundays River Thamnochortus species showed affinity with Thamnochortus erectus, Thamnochortus muirii and Thamnochortus spicigerus in some characters and affinity with T. insignis on other characters. The Sundays River species formed a single group in the cluster analysis and in the PCA analysis suggesting that species is different from the other Thamnochortus species. Thus the Sundays River species appears to be morphologically different from the Western Cape species and should perhaps be considered a new species. However, more studies on genetic variation between these species are required to substantiate these findings. Analysis of genetic variation in Moringa oleifera (lam.) using RAPDs and SSRs R. Smit, E.S. Du Toit, B.J. Vorster Department of Plant Production and Soil Science, University of Pretoria, Pretoria 0002, South Africa M. oleifera is potentially an economically important tree species. It has gained interest globally for its multipurpose uses, in particular as a source of nutrition and oil as well as various medicinal properties. Moringa is native to India, Malaysia and the Middle East, but has been introduced to many countries throughout Africa ranging from Niger to South Africa. There is however limited knowledge regarding the genetic variation of both native and introduced populations of Moringa, although phenotypic observations suggest the presence of significant genetic diversity. In this study we aim to determine the level of genetic variation found between different populations of Moringa from locations including India, South Africa, Malawi and Hawaii. Molecular markers such as Random Amplified Polymorphic DNA (RAPD) and Simple Sequence Repeats (SSR, will be used to analyze the genetic diversity based on their success in other tropical tree population studies). Their low capability for SSR conservation, make them ideal for the application at the intra-specific level. Various RAPD primers and 20 SSR primer pairs will be used to generate amplification profiles that can be used in a diversity analysis. Early screening has identified markers that show significant genetic diversity amongst the population. Furthermore the study will try to identify markers related to quantitative traits such as seed oil content and yield that could potentially be useful in future selection and breeding programs aimed at tree improvement. 239 How generalized is the pollination system of Hypoestes aristata? C-J. Thorne, C. Gornall, C.I. Peter Department of Botany, Rhodes University, Grahamstown 6140, South Africa Generalized pollination systems are underrepresented in the literature. Observations have shown numerous insects and birds visiting H. aristata (Vahl) Sol. Ex Roem. & Schult var. aristata. We therefore set out to test hypothesis that this species is an extreme generalist by 1) recording the suite of insects and birds visiting the flowers 2) determining pollen loads of the most frequently collected insect visitors and 3) the visitation rates of different pollinators. We recorded a total of 45 species of insects visiting the flowers. These represented 19 families and 4 orders. In addition, four species of sunbirds have been observed visiting the flowers opportunistically. The orders Diptera and Hymenoptera were shown to have the greatest pollen loads, in particular species from the families Acroceridae, Nemistrinidae and Apidae. Although late in the season honeybees were by far the most abundant visitors and showed the highest visitation rate. In conclusion, a wide variety of pollinators visit H. aristata and contribute to this generalized pollination system but late in the season honeybees predominate. The treatment of persistent headache in HIV/aids related patients by the traditional healers of Vhembe District Municipality, Limpopo Province, South Africa T. Tshilande, M.P. Tshisikhawe Department of Botany, University of Venda, Thohoyandou 0950, South Africa The recent study was about indigenous medicinal plants used by traditional healers in the treatment of persistent headache in HIV/AIDS related patients of Vhembe District Municipality, Limpopo Province, South Africa. In this study knowledge of traditional healers was used in order to collect data. Data was collected through the use of interviews. Questions such as the cause, symptoms and treatment of persistent headache were asked, and also the preparation and dosages were asked through interviews. In this study, traditional healers reported that 45 plant species were used in the treatment of persistent headache and of those plants; 31 were identified given their family, scientific name and given information about their other medicinal uses. It was concluded that indeed knowledge of traditional healers is of importance in the treatment of persistent headache as well as for the patients infected by HIV/AIDS. Landscape functionality and plant diversity in urban and rural grassland fragments in the Tlokwe Municipal area L. Van der Walt, S.S. Cilliers, K. Kellner, M.J. Du Toit 240 SAAB Conference Abstracts School of Environmental Sciences and Development, NorthWest University, Potchefstroom, South Africa The effect of four medicinal plants on oral Candida albicans isolates Grassland habitats around the world have been identified as a biodiversity conservation priority. South Africa's grassland biome, covering 16.5% of the country's surface, is one of the biologically richest in the country. Unfortunately nearly 30% of it has been transformed by activities such as urbanization, cultivation, mining, and forestry. The remaining untransformed grassland areas are fragmented to a critical extent, such as the Rand Highveld grassland vegetation type. A mere 1% of this endangered vegetation type is currently being conserved. The fragmentation, transformation and exotic species invasion of landscapes worldwide are threatening biodiversity and altering ecological processes, spatial organization of physical landscape attributes, as well as species distribution and composition. Fragmentation of the Rand Highveld Grassland may also influence the functionality of such landscapes. To understand how a landscape functions, and why a landscape may be deemed functional or healthy, knowledge about the processes taking place in landscapes (to enable it to function effectively as a biogeochemical or biophysical system) must be obtained. This can be done using the Landscape Function Analysis (LFA) method. Patches play a vital role in landscapes by capturing and utilizing natural resources such as water, nutrients, and soil sediments and are thus indicators of the extent to which landscapes are functional or dysfunctional. Generally habitat remnants in urban areas are considered to be extensively disturbed and no longer functional or species rich, leading to a perception that these fragments need not be as actively conserved as fragments in rural or more “natural” landscapes. In this proposed study we aim to quantify an urban–rural gradient, and describe differences and similarities between urban and rural grassland fragments in terms of species composition, species richness, functional diversity and landscape functionality, in the Tlokwe Municipal area, situated in the Rand Highveld Grassland vegetation type. This comparison will allow for recommendations to be made in terms of conservation priorities of grassland remnants. C. Van Wyk a, F.S. Botha a, V. Steenkamp b, J.N. Eloff a a Phytomedicine Programme, Department of Paraclinical Sciences, Faculty of Veterinary Sciences, University of Pretoria, South Africa b Department of Pharmacology, School of Medicine, Faculty of Health Sciences, University of Pretoria, South Africa Crude acetone, water and hexane extracts of four plant species, used as traditional medicine to treat fungal related diseases or shown to contain antifungal activity, were evaluated so as to identify new sources of chemical entities which can be used in the treatment of fungal infections. Antifungal activity against C. albicans standard strain (ATCC 10231) and six clinical isolates was determined using the serial microplate dilution method. Antioxidant activity was determined using the TEAC and DPPH assays and cytotoxicity against mouse fibroblast cells. MIC's below b1 mg/ml were observed for the acetone and water extracts of S. birrea (stem–bark), as well as the acetone extracts of Harpephyllum caffrum (leaves), P. obliquum (leaves) and R. melanophloeos (leaves). Bioautography confirmed the presence of compounds with antifungal activity in S. birrea and P. obliqum. S. birrea contained the highest antioxidant activity with the lowest cytotoxicity. These results implicate that the extracts contain compounds with therapeutic potential against oral C. albicans isolates.