Nature of gene action for kernel yield and its component traits in maize (Zea mays L.)

Towards understanding the nature of gene action for kernel yield and its components traits, a set of 45 F₁ hybrids generated by adopting diallel mating design (Method IV and Model I) involving 10 inbred lines were tested across three seasons for their performance and combining ability. Combining ability analysis revealed that the mean sum of squares due to general and specifc combining ability were signifcant indicating the contribution of both additive and non-additive gene action in controlling days to 50% fowering, days to 50% silking, anthesis-silking interval, days to maturity, plant height, SPAD chlorophyll meter reading, specifc leaf area, cob length, cob girth, number of kernel rows per cob, number of kernels per row, 100 kernel weight, harvest index and kernel yield. Estimates of components of variances (²GCA and ²SCA) and ratio of ²GCA/²SCA indicated the predominance of non-additive gene action for all the characters studied. Among the inbred lines, BML 2, DFTY, Heypool and PDM 1474 were found to be the best general combiners across seasons for kernel yield and most of yield components as well as developmental characters. DFTY, Heypool, PDM 1452 and PAM 1474 were identifed as good general combiners for earliness. Among the top 20 best performing hybrids, BML 15 × PDM 1452, BML 15 × PDM 1474 and BML 7 × DFTY were rated as promising hybrids based on their superior performance and sca effects for kernel yield and most of the yield components. These hybrids could be recommended for commercial cultivation after extensive testing in multilocation trials.