Diversity in common bean landraces from south Brazil.

Abstract

Phaseolin is the major protein in legume seeds and has provided evidence for protein diversity studies, particularly for subdividing Phaseolus vulgaris in two major gene pools: the Central American (S-type) and the Andean (T-type) groups. In the work reported here, a total of 73 representative landrace genotypes from Santa Catarina State, Brazil, were evaluated according to their phaseolin patterns using sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE). The seed traits analyzed were: a) the 100-seed weight (P100); b) seed shape degree and seed flattening as determined by J and H coefficients; c) soluble and total protein contents; and d) seed colours. The data indicated that landrace genotypes of common bean collected in Southern Brazil were from both gene pools (Central America and Andes) with both »S« (53.42%) and »T« (42.46%) phaseolin types. The P100 was the main character that grouped these gene pools. The landrace genotypes of the common bean showed a wide range of seed size associated with seed colour. The grouping used by comparison of means, allowed efficiently identify promising genotypes to compose valuable source of genetic diversity that would be highly useful for future studies of representative genotypes from each group. The accession numbers 11, 25, 26, 46, 48 and 74 are of interest for breeding purpose, for they showed higher productivity associated with high protein content.