Understanding the genetics of important quality traits in maize (Zea mays L.) using diverse germplasm by generation mean analysis

Abstract

The information about gene actions and interactions would most likely to direct and reinforce the crop breeding programs. With this objective, the present investigation was undertaken by using six generations P1, P2, F1, F2, BC1, and BC2 derived from six different crosses in maize, evaluated at CCS Haryana Agricultural University, Regional Research Station Karnal from Kharif 2015 to 2016. The study underscores the significance of additive–dominance model, gene action involved in the inheritance of grain yield and quality traits. Both the scaling test and the joint scaling test detected nonallelic interactions affecting the traits, showing the inadequacy of the additive–dominance model alone in describing the manifestation of complex traits like yield and quality traits except for oil content in cross HKI 325-17AN × HKI 1128. Both additive genetic effects and dominance effects were found significant with positive and negative magnitude in all the crosses. On the note, different types of interallelic interactions (i, j, l) contributed to the inheritance of traits in the given crosses. And among them, the dominance × dominance component (l) gene effect also played a major role in the inheritance of the studied traits. Duplicate epistasis was prevalent in all the crosses for grain yield and also for protein, tryptophan, oil, and starch content in some crosses whereas a complementary type of interaction was reported for protein content in cross HKI 325-17AN x HKI 1128 and oil content in cross HKI 209 x HKI 163. In view of the diverse gene actions, i.e. additive, dominant, and epistasis, playing important roles in the manifestation of complex traits like yield and quality traits, we advocate the implementation of population improvement techniques in particular reciprocal recurrent selection to improve productivity gains in maize in terms of both yield and quality. It is concluded that crosses, where dominant gene action was found predominant, should be effectively utilized in hybrid maize programs for improved grain yield and quality traits.