Studies on Reciprocal Differences and Gene Actions through Diallel Analysis in Sesame (Sesamum indicum L.)

A combining ability analysis was carried out in a 7 × 7 diallel mating system for nine quantitative characters in sesame. The results revealed that the variance due to gca, sca and rca were highly significant, denoting the importance of both additive as well as non additive genetic components for yield and yield contributing characters. The magnitude of the gca variance was higher than the sca variance. The magnitude of the latter, when compared to the variance due to the reciprocal effect, was highly significant and higher for the characters, number of capsules per plant, number of seeds per capsule, while the magnitude of the rca variance was highly significant and higher than the sca variance for the characters days to maturity, plant height, number of branches per plant, number of capsules per plant, capsule length, 1000 seed weight and seed yield per plant. This indicated the presence of reciprocal effects for these characters as both additive and non-additive genetic components are involved for yield and yield contributing traits. The additive genetic variances could be improved in the future by a simple selection, whereas no fixable genetic variances can be improved by following biparental mating of the F₂ generation.