Estimation of genetic variance from full-sib and half-sib families in a maize (Zea mays L.) composite

Abstract

Sixty four randomly selected So plants (used as males) were each mated to four different plants (used as females) to generate 256 full-sib families as per North Carolina Design-1 for the estimation of genetic components of variance and related parameters in a large random mating maize composite Mahidhawal. These 256 full-sib families were evaluated in an incomplete block design with two replications in rainfed farming situations under two different fertility levels. Comparison of the relative magnitude of the additive genetic variance and variance due to dominance deviations revealed that the former was more important for grain yield per plant and its component traits. Variance due to dominance deviations was affected more by the environmental interaction as compared to additive genetic variance. Genes responsible for the expression of majority of the traits showed no dominance to partial dominance, indicating that (J2 A was the sole contributor to total genetic variability. Heritability (narrow sense) estimates showed that sufficient proportion of additive genetic variance was available for an effective selection procedure to be used.