Geographical variation of phaseolin patterns in an Old World collection of Phaseolus vulgaris

Screening of 372 accessions from a germplasm collection of Phaseolus vulgaris by SDS/PAGE was carried out to evaluate their variation for phaseolin patterns. Out of 1059 single seed examined, 26.6%, 36.2% and 36.9% had phaseolin patterns of the T, S, C types, respectively. One exception was Bonello cv showing a rare banding pattern. A narrow range of heterogeneity was observed within patterns S and C showing a number of sub-variants with minor differences from the reference patterns. Greater variation was found in accessions of wild material with phaseolin banding types somehow ascribable to the patterns described for cultivated materials. Because of the narrow variation of phaseolin patterns, electrophoretic analyses of seed storage proteins in P. vulgaris proved to be a useful tool for species identification.