A team of U.S. scientists has sequenced and assembled the genome of the Gossypium herbaceum cultivar Wagad, representing the first domesticated accession for this species.
Gossypium herbaceum. Image credit: Xavierserratm / CC BY-SA 4.0.
The cotton genus Gossypium comprises the primary source of natural fiber worldwide.
While the genus itself is composed of over 50 known species, only the fiber from four species is suitable for textile production.
Remarkably, these four species were each independently domesticated, providing a naturally replicated experiment with which researchers can understand the underlying genetic changes that lead to phenotypic convergence.
While much research has been centered around understanding domestication in two dominant cultivated species, i.e. Gossypium hirsutum and Gossypium barbadense, considerably less is known about the domestication in the ‘short staple cottons,’ Gossypium herbaceum (commonly known as Levant cotton) and Gossypium arboreum.
The chromosome-level genome of the Gossypium herbaceum cultivar Wagad was generated using a combination of PacBio long-read technology, HiC, and Bionano optical mapping.
“The power of our technology is it allows us to create high-quality genomes that supply a level of detail that simply wasn’t possible before,” said Dr. Thiru Ramaraj, a researcher at DePaul University.
“This opens up the possibility for more researchers to sequence many crops that are important to the global economy and to feeding the population.”
The team annotated 39,100 unique genes of the Wagad cultivar genome and noted their functions.
“As we were studying the regions of the genome, we found many genes that were related to the content of fiber,” said Azalea Mendoza, a graduate student at DePaul University.
“It was incredible to see the real-life application of the work.”
The authors also compared the genome of the Wagad cultivar to the existing genome of wild Gossypium herbaceum subspecies africanum.
“Our results demonstrate the utility of the Gossypium herbaceum cultivar Wagad genome in understanding domestication in the diploid species, which could inform modern breeding programs,” they said.
The findings appear in the journal G3: Genes, Genomes, Genetics.
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Thiruvarangan Ramaraj et al. 2023. The Gossypium herbaceum L. Wagad genome as a resource for understanding cotton domestication. G3: Genes, Genomes, Genetics 13 (2): jkac308; doi: 10.1093/g3journal/jkac308
