Cowpea Genome Resources Developed in Support of Breeding

Cowpea (Vigna unguiculata (L.) Walp) 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 along with soybean, common bean and pigeon pea in the Phaseoleae tribe of the family Fabaceae, thus sharing extensive genome similarities with these taxonomic relatives. Recently, considerable progress has been made in the establishment of core genomic resources of cowpea. The main resource of relevance to breeding is a set of well-tested SNP markers selected from a genetic map composed of 1107 SNP loci in 856 bins, developed from 1293 individuals in 13 mapping populations. A transition to marker-assisted breeding by NARS in Africa is underway to expedite delivery of improved crop varieties, presently using linked SNP markers for resistance to bacterial blight, ashy-stem blight, foliar and flower thrips, root-knot nematodes and tolerance to drought. Additional resources that support basic research on cowpea include a physical map and draft genome sequence; these have involved numerous individuals who will be cited in the workshop presentation.