Translational Genomics of Cowpea

Cowpea (Vigna unguiculata (L.) Walp), native to East Africa, is a primary source of protein in Sub-Saharan Africa where it is grown for fresh and dry grains, and for foliage. Cowpea is grown also in parts of Asia, Latin America, South America, Southeastern USA and California. Cowpea is a warm season legume with soybean, common bean and pigeon pea in the Phaseoleae tribe, sharing extensive genome similarities with these relatives. Core genomic resources now include a draft genome sequence and a 10X physical map of African breeding parent IT97K-499-35. These have been coupled via a consensus genetic map composed of about 1100 transcript-derived SNPs and sequences of nearly 4000 minimal tiling path (MTP) BACs. The genetic map was developed from 11 RIL populations. Sequences are available for BLAST from a whole genome shotgun assembly and MTP BACs via harvest-blast.org, retrievable via harvest-web.org. HarvEST:Cowpea  (http://harvest.ucr.edu) provides a portable interface to the coupled genetic and physical maps, while also providing a synteny-based interface. A transition to marker-assisted breeding has been underway in our breeding programs. Nearby markers of traits have been identified from biparental RILs, backcross progeny, and broad germplasm using genetic association. Mapped traits now include resistance to Striga, bacterial blight, Fusarium races 3 and 4, aphids, thrips and root-knot nematode; seed size and coat color; components of tolerance to water-limited environments including delayed senescence and recalcitrance to ashy stem blight; and several morphological and developmental traits. This genetic knowledge is increasingly integrated into breeding strategies. This work has been supported mainly by funding from the CGIAR Generation Challenge Program and USAID CRSP and Feed the Future Innovation Lab programs.