Generation mean analysis in quality protein maize (<i>Zea mays</i> L.) for yield and quality attributes

Maize (Zea mays L.), the world’s most significant cereal crop, provides a pivotal roles for the supply of food for humans and forage for livestock. The present study aimed to perform a Generation mean analysis of two quality protein maize (QPM) (Zea mays L.) crosses [(CML149 x CML330) and (CML143 x CML193)] in order to determine the genetic effects along with the nature of gene action controlling morphological and biochemical traits underlying inheritance. All four components of scaling testing revealed significant differences with the parameter model, indicating the importance of the additive, dominance and epistatic modes of gene action for the inheritance of physiological, biochemical, grain yield and its attributing traits. Dominance variance showed more importance than additive variance and the presence of duplicate form of non-allelic gene interaction was prevalent for all the characters studied except days to 50% silking in CML149 × CML330 ([h] = 2.064, [l] = 1.536) and membrane stability index in CML143 × CML193 ([h] = 4.055, [l] = 17.362) which showed complementary gene action. Characters with duplicate genes, grain yield per plant in CML149 × CML330 ([h] = 1545.776, [l] = -2126.616) and plant height in CML149 × CML330 ([h] = 113.336, [l] = -104.376) showed strong dominance and dominance x dominance gene action. The significant role of dominance variance and duplicate epistasis was noted in the inheritance of the aforementioned characters. Selection could be rewarding for consecutive populations, followed by a bi-parental mating design to improve these traits.