Heterosis in Relation to Gene Action in Chickpea

In the present investigation, six genotypes of chickpea viz., PG0127, PG0126, CSG8962, ICCL87322, HC1 and BG362 and their 15 F1 hybrids were used for combining ability studies through 6 × 6 diallel analysis and heterosis studies with respect to grain yield and other yield contributing traits namely, days to 50% flowering, days to maturity, plant height, number of primary branches per plant, pods per plant, seeds per pod, seeds per plant and 100 seed weight. For major grain yield components, namely, number of pods per plant, number of seeds per plant, 100-seed weight and shorter plant height, the heterosis was observed due to good gca of the parents and/or due to high sca effect of the respective crosses. The proportion of crosses showing significant positive heterotic effects was greater with the line BG362, HC-1 and PG0127. Hence, direct selection for higher values of yield components can be made in the advanced generations of the heterotic crosses involving such parents, as a large portion of the total variation is a result of additive gene effects. The results showed direct association between the specific combining abilities of the crosses and heterotic response indicating the involvement of additive x additive type of interactions causing heterosis. Choice of best cross combination on the basis of high SCA or per se performance would not necessarily give high heterosis. The GCA, SCA and per se performance of the crosses should be given equal importance while selecting for heterotic combinations.