Abstract

This study was conducted on quality protein maize crosses, CML138 × CML145 and CML334 × CML330, to assess genetic effects and the nature of gene action governing morphological and biochemical traits. The significant results from all four scaling tests and the six-parameter model highlighted the roles of additive (d), dominance (h), and epistatic effects (i, j, and l) in the inheritance of morphological, biochemical, and grain yield-related traits. Dominance variance (h) had a greater influence than variance (d), with duplicate epistatic interactions observed for most traits, except plant height in CML138 × CML145 (h) = 23.944, (l) = 22.656, and catalase activity in CML334 × CML330 (h) = 0.083, (l) = 0.121, which exhibited complementary gene action. Traits exhibiting duplicate gene action, such as grain yield per plant in CML138 × CML145 (h) = 1757.704, (l) = −2088.704 and plant height in CML334 × CML330 (h) = 108.636, (l) = −162.936, exhibited significant dominance (h) and dominance × dominance (l) interactions. Dominance variance and duplicate epistasis played a crucial role in the inheritance of these traits. To enhance these characteristics, selection in successive populations following a biparental mating approach would be beneficial.

Key words: Additive effect, dominance effect, GMA, Non-allelic interactions, QPM