Estimates of combining ability, reciprocal effects and heterosis for yield and yield components in a common bean diallel cross

A diallel crossing system involving two Pinto and two Kidney common bean (Phaseolus vulgaris L.) cultivars was evaluated in the field. Pintoes were significantly different from the Kidneys in seed yield and numbers of pods and seeds per plant and 100-seed weight. All the traits showed statistical significance among crosses and in comparisons involving parental v. cross means. Heterosis values were large and significant for yield, numbers of pods and seeds per plant, number of seeds per pod and number of days from planting to flowering. The ratio of general to specific combining ability mean squares was low for yield, numbers of pods and seeds per plant and high for 100-seed weight and number of days to flowering. Significant reciprocal effects were found for seed yield and number of seeds per plant, but this effect was completely absent for 100-seed weight.