Inheritance of Yield and its Components in Two Bread Wheat Crosses Under Normal and Water Stress Conditions

Abstract

The present investigation was conducted at Shandaweel Agricultural Research Station-Field Crops Research Institute (FCRI), Agricultural Research Center (ARC) through three successive winter seasons from 2015/16 to 2017/18. The experimental material included six populations i.e. P 1 , P 2 , F 1 , F 2 , BC 1 , and BC 2 for two bread wheat crosses viz Shandaweel 1 × Sids 1 and Line 1 × Sids 12. Six parameters model was applied for studying inheritance of seven agronomic traits; days to heading (DH), no. of spikes/plant (S/P), plant height (PLH), biological yield / plant (BY), grain yield/plant (GY),100-grain weight (100-KW), and no. of kernels/spike (K/S) under normal irrigation (5 irrigations) and water stress conditions (3 irrigations). The results showed significant or highly significant differences among the included materials. Mean performance of F 1 generation in cross 1 and cross 2 override mid-parents or/and best parent for most of the reviewed traits under investigation except plant height in cross 2 under stress conditions. The results of scaling tests indicated that at least one of these scales is significant and additive-dominance model is inadequate, consequently six parameters model is applicable. The results indicated that gene main effect was highly significant for all the studied traits. Additive gene effect was significant for most of the traits in combinations of the crosses and environments. The results showed that non-allelic interactions were significant or highly significant with positive sign for some traits and with negative sign for the others. The results indicated that duplicate epistasis was predominant while complementary epistasis was found only in one case. The average degree of dominance indicated presence of partial, complete, and over dominance. Broad, narrow sense heritability and genetic advance values were moderate to high. The results of the current investigation revealed that the included material can be used for producing high yielding lines under stress water conditions deploying selection in early generation for some traits and in advanced generation in the others.