Heterosis and combining ability in blackgram (Vigna mungo) under different environments

Abstract

A diallel set of 10 parents and their 45 f₁ and 45 f₂ hybrids were analyzed to estimate the magnitude of heterosis and to understand the nature and magnitude of gene action under different environments for seed yield and its component characters of blackgram [Vigna mungo (L.) Hepper]. As the genotype × environment interaction was significant for all the traits, hence the combining ability was carried out for each environment separately. The combining ability analysis revealed that the GCA and SCA variances were significant for all the characters in each of the three environments indicating the importance of both additive and non-additive genetic control of all the characters under study. Some parents having consistent desirable GCA estimates for some characters in most of the environments were UH 84-14 for days to 50 per cent flowering, harvest index (HI) and seed yield/plant; GU 1 and RBU 38 for harvest index (HI) and seed yield/plant; VBN 3 and VBN 4 for pod weight and seed yield/plant. Overall crosses based on high per se performance, high SCA effects, high heterobeltiosis and high standard heterosis only for seed yield per plant were VBN 3 × UH 84-14 and RBU 38 × UH 84-14 in E₁ and NUL 7 × UH 84-14, IU 8-6 × UH 84-14 and IU 8-6 × VBN 4 in E₃. As the environmental effect on the expression of the character was very high, different crosses emerged in different environments for seed yield/plant. Thus, these crosses can be included in the breeding programme for improvement in yield in specific environment.