Submitted to: PLOS ONE
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/27/2016
Publication Date: 8/10/2016
Citation: Xiong, H., Shi, A., Mou, B., Qin, J., Motes, D., Lu, W., Ma, J., Weng, Y., Yang, W. 2016. Genetic diversity and population structure of cowpea (Vigna unguiculata L. Walp). PLoS One. 11(8):e0160941. doi: 10.1371/journal.pone.0160941.

Interpretive Summary: Genetic diversity was analyzed in a set of 768 cowpea varieties in the USDA NPGS cowpea collection that originated from 56 countries. DNA sequencing was used to discover molecular markers in cowpea that were used to estimate the level of genetic diversity and genetic relationships. The aims of this research were to detect the gene pool structure of cowpea and to determine the relationships between different regions and countries. According to the genetic analyses of each variety, region and country, we may trace the variety back to West and East Africa, the two areas considered to be the center of origin for cowpea. Thus it can reveal the migration and domestication history during the cowpea dispersal and development. This is the first synthesis and analysis of the genetic variation and relationships among cowpea varieties from around the world. The results will help breeders to understand, utilize, conserve, and manage the collection for more efficient international cowpea research.

Technical Abstract: The genetic diversity of cowpea was analyzed and the population structure was estimated in a diverse set of 768 cultivated cowpea genotypes from USDA GRIN cowpea collection, originally collected from 56 countries worldwide. Genotyping by sequencing was used to discover single nucleotide polymorphism (SNP) in cowpea and the postulated SNP alleles were used to estimate the level of genetic diversity, population structure and phylogenetic relationships. The aims of this research were to detect the gene pool structure of cowpea and to determine their relationship between different regions and countries. According to the phylogenetic analyses between each individual, region and country, we may trace the accession from off-original back to the two candidate original areas (West and East of Africa) to predict the migration and domestication history during the cowpea dispersal and development. This is the first time to synthesize and analyze the genetic variation and relationship between global cultivated cowpea genotypes. The result will help breeders to understand, utilize, conserve, and manage the collection for more efficient service to international cowpea research.