Determining the Genetic Action of Water and Nitrogen Utilisation Efficiency in Maize (Zea mays L.)

Abstract

A study to observe and record the mode of gene action involved in some quantitative and physiological traits of three maize hybrids using generation mean analysis was conducted at Abu Garash Farm, Faculty of Agriculture, Damascus University, during two growing seasons (2018 and 2019). Genotypes were compared using Randomised Complete Block Design (RCBD) with three replicates. Significant differences in all studied traits for six populations within each cross were found. There was significant positive heterosis relative to intermediate and better parents for most studied traits of hybrids, except in nitrogen utilization efficiency. Most of the genetic parameters were significant for the three hybrids, indicating the importance of epistasis in the inheritance of studied traits. The dominance gene effect was more pronounced than the additive gene effect in the inheritance for all traits. The values of the phenotypic coefficient of variance were greater than the values of the genotypic coefficient of variance, indicating the effect of environmental factors on the expression of the studied traits. High narrow-sense heritability values were associated with high genetic advance for nitrogen use efficiency and biological yield per plant. It is recommended that selection in early segregating generations of the studied hybrids is useful.