Genetic Mechanism of Morpho-Physiological and Some Agronomic Characters of Ten Bread Wheat Genotypes

Abstract

Ten bread wheat cultivars from Egypt were crossed in a half diallel design without reciprocals in 2009 /10 season to estimate the genetic effects. Parents and F1`s were evaluated in a randomized complete block design (RCBD) with three replicates in 2010/11 season at Sakha Agric. Res. St. Data were recorded on some morphophysiological and agronomic characters. High significant differences were observed among genotypes for all studied traits. Significant mean squares of combining ability for all characters reflected the role of additive and non-additive effects in the inheritance of the characters. The ratio of general combining ability to specific combining ability (GCA: SCA) indicates that the effect of general combining ability was more prominent for all characters except for grain yield per plant. Among parents, Sids 12 proved the best general combiner for number of days to heading, number of days to maturity, number of kernels per spike, kernel weight and grain yield per plant. Meanwhile, Sakha 94, Gemmeiza 9, Gemmeiza 11 and Misr 2 were the best general combiners for plant height. Moreover, Sids 13, Misr 1 and Misr 2 were the best general combiners for number of spikes per plant. So, these general combiners should be used in breeding programs to enhance most of studied traits. The crosses; Sakha 93 × Sids 12, Gemmeiza 11 × Shandweel 1, Sids 12 × Sids 13, Sids 12 × Misr 1 and Misr 1× Misr 2 included the good combiner parents for improvement of grain yield. The additive genetic component (D) and dominance components (H1 and H2) proved to be significant for most of studied characters. Mean degree of dominance (H1/D) 1/2 indicated over dominance gene effects for all studied characters except for plant height which is controlled by partial dominance gene effects. Moderate to high heritability estimates in narrow sense (h 2 n) were detected for all studied traits except for grain yield per plant which had low estimate.