GENETIC ANALYSIS FOR YIELD, ITS COMPONENTS AND RUSTS RESISTANCE IN FOUR BREAD WHEAT CROSSES

doi:10.12816/ejpb.2019.344264

GENETIC ANALYSIS FOR YIELD, ITS COMPONENTS AND RUSTS RESISTANCE IN FOUR BREAD WHEAT CROSSES

Document Type : Original research

10.12816/ejpb.2019.344264

Abstract

The present study was executed at Nubaria Agricultural Research Station during the three growing seasons from 2014/2015 to 2016/2017 to estimate the type of gene action using the six populations (P₁, P₂, F₁, F₂, BC₁ and BC₂) of four wheat crosses cross #1 (Sakha 93×Giza 171); cross #2 (Shandaweel 1× Giza 171); cross #3 (Shandaweel 1×Gemmeiza 11) and cross #4 (Shandaweel 1×Gemmeiza 12). The studied characters were grain yield and its components, resistance to yellow rust and leaf rust diseases. Results indicated significant positive heterotic effects relative to better and mid parents for number of spikes/plant, number of kernels/spike, 100-kernel weight in cross 1 and grain yield/plant in cross #3. Results indicated the presence of non-allelic interaction for most studied characters in all crosses under the study. Meanwhile, the relative importance of additive, dominance and epistatic effects varied among characters and crosses, the relative importance of dominance and epistatic effects were shown for number of spikes/plant and number of kernels/spike. The additive and epistatic effects were important for 100-kernels weight and grain yield/plant characters. Average degree of dominance was less than unity for all characters in all crosses, indicating the presence of partial dominance except for number of spikes/plant and grain yield in cross #3 which indicated the presence of over dominance. Significant positive values of inbreeding depression were detected for yield and its components in all crosses, except for grain yield in crosses # 2 and 3 which were not significant. Heritability estimates in broad sense were high to medium for all studied characters in all crosses, but in narrow sense, estimates were high to low for all characters in all crosses. The expected genetic advance as a percent of F₂ ranged from high to low in all crosses for all characters. Based on these results, cross # 4 (Shandweel 1 x Gemmeiza 12) showed high genetic advance associated with high heritability and thus could be promising in breeding programs of wheat and selection for obtaining high grain yield plants and resistance to rusts.

Keywords