Vignin diversity in wild and cultivated taxa ofVigna unguiculata (L.) walp. (fabaceae)

Eighty-one cultivated and 55 wild accessions were characterized using one- and two-dimensional isoelectric focusing (1D and 2D IEF)/SDS-PAGE and immuno-detection techniques to examine genetic diversity present within cultivated and wild taxa inVigna unguiculata (L.) Walp. Twenty-seven unique banding patterns were identified in the vignin (or Gl) fraction of the major seed storage proteins. These patterns were controlled by at least four interacting genes, two of which were tightly linked and a third which also may be linked. Due to the tremendous amount of variation in these wild taxa it is not possible to make definitive statements about either the taxonomic or geographic distribution of vignin types. These results give no final answer to the identity of the progenitor of cowpea or the center of domestication, but do pose some interesting questions to be asked as the genetic relationships among the wild and cultivated taxa in this species are unraveled.