Study of Gene Action and Heterosis Effects of Different Genotypes for Yield and Yield Attributing Traits in Maize (Zea mays L.)

A study of Line × Tester analysis involving 8 lines and 5 tester of yellow maize was carried out to identify high heterotic crosses and their relationship in terms of general and specific combining ability effects (gca and sca) for yield and its component traits. Analysis of variance exhibited highly significant difference among all the parents for different traits under study. The ratio of σ2gca/σ2sca was less than unity there by indicating the preponderance of non-additive gene action in the expression of majority of the characters studied. The line Z 488-4 and tester BLD 47 were identified as most promising parents due to having good general combining ability for grain yield and several other yields contributing traits. Among the crosses, HYN-10-RN 235-270 × IC 328963 and BLD 254 × BLD 47 proved as good specific combiner for kernel yield per plant and its component traits while for earliness cross BLD 254 × IMR 53 were found good specific combiner. On the basis of heterosis cross Z 488-4 × IMR 53 and BLD 266 × BLD 47 was found superior for kernel yield per plant, ear yield per plant, days to tasselling, days to silking, days to dry husk, ear girth and 100 kernel weights. Therefore, these crosses need to be further evaluation for genotype x environment interaction over different seasons and or locations.