Quantitative Studies on Resistance to Stripe and Stem Rust Diseases and on Grain Yield of Bread Wheat

This work was carried out at the Experimental Farm of Sakha Agricultural Research Station, Kafr El-Sheikh, Egypt, during the three growing seasons 2013/14, 2014/15 and 2015/16, to estimate types of gene action controlling the inheritance of wheat resistance to stripe and stem rust diseases as well as to study the inheritance of grain yield character. Genetic materials used in this study included six populations (P1, P2, F1, F2, BC1 and BC2) of two bread wheat crosses namely, (Sakha 95 X Shandaweel 1) and (Sakha 95 X Sids 13). Results revealed that additive (a) was higher in magnitude than dominance (d) variance for all charcters. The most predominant type of epistasis was additive X additive (aa) for both diseases; stripe and stem rust resistance. The values calculated for heritability in broad sense were high, while for narrow sense heritability values were moderate to relatively high for the two crosses in all studied characters. Both crosses are promising and higher in magnitude, which had high genetic advance associated with high heritability estimates were detected. Therefore, these two crosses would be useful in breeding programs for improving the studied characters.