Association Analysis in Cowpea.

Cowpea (Vigna unguiculata L. Walp.) (2n=2x=22) is an important annual legume widely grown in Africa, Latin America, and Southeast Asia and in the southern United States and it is chiefly used as a grain crop for food, and it can also be used as animal fodder, or as a fresh vegetable. The objective of this project is to identify SNP markers through marker: traits association analysis. A total of 768 cowpea germplasm were genotyped through Genotyping by Sequencing (GBS). The genome-wide association is conducted for morphologic traits such as plant habit, dry pod color, pod placement, seed pattern and color, and seed coat color, for agronomic traits such as grain (seed) yield, 100-seed weight and seed size, for abio- and biotic (disease and pest) resistance/ tolerance such as cowpea wilt (Fusarium oxysporum f. sp. tracheiphilum) resistance, cowpea mosaic virus (CPMV) resistance, bacterial blight (Xanthomonas axonopodis pv. vignicola) resistance, cowpea aphid tolerance, iron deficiency chlorosis (IDC) tolerance, and low phosphorus efficiency; and SNP markers are identified for these morphologic, agronomic, abio- and biotic, and seed quality traits. This research will provide breeders a tool to select these traits through marker-assisted selection (MAS) in cowpea breeding program.