Vigna vexillata (L.) A. Rich. seed proteins: heterogeneity in subunits of globulin fraction

Forty-six accessions of Vigna vexillata from Africa, America and Australia were screened for variability in globulin protein fraction by using SDS-PAGE under reducing and non-reducing conditions. The globulin fraction was composed of several bands clustering in two size fractions, both of which were polymorphic. The high molecular weight fraction was constituted by one or two subunits, while the fraction of lower molecular weight exhibited from two to four bands. Two single types were found within the collection. Due to the observed polymorphism only the subunit at 52 kD was species-specific. Southeastern Africa proved to be the region with the highest diversity for Vigna vexillata. Different frequencies of the globulin patterns were observed between the African and American groups of accessions. No significant differences were found comparing the distribution of the globulin types between the varieties vexillata and angustifolia.