Gene Pool Specificity, Paucity of Enzyme Variation, and Phaseolin Polymorphism in the Common Bean

Abstract

The future of molecular markers in common bean (Phaseolus vulgaris L.) breeding and genetics lies in the discovery of more useful markers than now available. One-dimensional SDS/PAGE analysis revealed four phaseolin types, “S,” “T,” “C,” and “H,” in proportions of 23.5%, 49.2%, 24.8%, and 2.5%, respectively. Molecular heterogeneity of phaseolin subunits was not apparent. On the basis of the phaseolin types and seed size, ≈75% of the landraces from Malawi probably were introduced from the Andean primary center of common bean domestication. The remaining 25% were small-seeded and probably originated from the Meso-American center of domestication of common bean. In Malawi, some amount of hybridization has occurred between genotypes from the two centers of domestication.