Cowpea: SNP-Based Diversity Analyses and Genetic Improvement for Marignal Environments.

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 foliage. Cowpea is a warm season legume along with soybean and common bean in the millettioid clade of the Papilionoideae sub-family of the Fabaceae, and is grown also in parts of Asia, Latin America, Southeastern USA and California. Recently, considerable progress has been made in the establishment of core genomic research resources. A transition to marker-assisted breeding is underway. New resources include a genetic map containing over 1100 single nucleotide polymorphism (SNP) markers, a 10X physical map coupled to the genetic map, and a 63X draft genome sequence. These resources are being applied to an assessment of diversity in germplasm collections and breeding materials, and to the development of new cowpea varieties with improved heat and drought tolerance, and resistance to nematodes, Fusarium, Macrophomina, aphids and thrips, while retaining other desirable traits such as seed color and pattern.