"Isogenic" lines of maize (Zea mays L.) inbred B14, differing by single marker genes and chromosome segments linked to these genes, were used to study gene action in the inheritance of 10 plant, ear, and grain characters. The 27 genotypes representing all combinations of the homozygous and heterozygous genotypes at three loci, rp, wx, and ws, were evaluated for three years. Highly significant differences among genotypes were observed for eight characters; genotype × year interactions were highly significant for seven characters, which included the two characters that were not different for genotypes. Additive effects were most important, followed by additive × additive epistasis, and dominance was relatively unimportant. Also, additive effects × years were generally the most important of the interactions, but except for the two characters that did not have significant differences among genotypes, the genotypic effect × year interactions were of considerably lesser importance than the genotypic effects.
Combining Ability Estimation and Gene Action in Maize (Zea mays L.), Using Line X Tester Method under Normal Irrigation and Water Stress Conditions