Identification of a Locus Controlling Seed Pigment Leaching in Cowpea [Vigna unguiculata (L.) Walp]

Abstract

Consumer preferences for cooking-related traits are a deciding factor in the success of new cowpea [Vigna unguiculata (L.) Walp] cultivars. Pigment leaching is an undesirable trait for both consumers and producers alike that occurs during the cooking or canning process and has been a goal for improvement efforts through breeding. This study leverages the power of bulked segregant analysis to identify a locus segregating for the pigment-leaching trait in an F2 population of blackeye seed-type cowpea. A single major locus was identified on Vu06 spanning 1.27 Mb, and SNP haplotypes were identified for low and high pigment-leaching bulks. However, further evaluation of accessions that are unrelated to the F2 population or its progenitors suggests that the trait is polygenic, such that low or high leakage is not determined solely by this locus. Parallels were drawn between cowpea and a close relative, black bean (Phaseolus vulgaris L.), to suggest that additional seed coat or cooking-related traits may also be involved in the pigment-leaching trait.