VIGNA PREFACE:

Fabaceae the third largest family of flowering plants with approximately 650 genera and 18,000 species (Polhill & Raven, 1981) of legumes includes important grain, forage and agroforestry species. Legumes are excellent colonizers of disturbed ecosystems and low nitrogen environment which also make them economic and environment friendly crops. Legumes account for 27% of world's primary crop production, with grain legumes alone contributing 33% of dietary protein nitrogen (N) needs of human (Vance et al, 2000). Vigna, originally published by Savi in 1824 who named it after Domenico Vigna, Professor of Botany at Pisa (Baudoin & Marechal, 1988). The genus Vigna Savi is a large pantropical genus with about 104 (Lewis et al., 2005) species distributed among 7 subgenera viz. Ceratotropis, Haydonia, Lasiosporon, Macrorhyncha, Plectotropis, Sigmoidotropis and Vigna (Marechal et al., 1978). There are 18 cultivated species (Maxted et al., 2004) including pulses like black gram, mung bean, moth bean, cowpea, azuki bean and rice bean. Black gram, mung bean and moth bean were first domesticated in India. Wild relatives of these crop plants are widely distributed in India, exhibit greater diversity and constitute an important source of germplasm for improvement of cultivars. Thus, Indian centre is centre of origin as well as centre of diversity for these crops. India, with 24 species of Vigna (Sanjappa, 1992), represents secondary centre of species diversity for all the three sections of subgenus Ceratotropis and are also known as Asian Vigna. Babu et al. (1985) revised Tribe Phaseoleae for India in which 23 species of Vigna are reported and described. Asia is the centre of diversity for subgenus Ceratotropis in Vigna. (Tamooka et al., 2002).