Evaluation of Intra-Genomic Variations for Grain Yield and its components under Non-stress and Water-stress Conditions Using Wheat Chromosomal Substitution Lines

In order to evaluate intra-genomic variation and regression analysis of grain yield and its components using two wheat substitution lines series including substitution lines of ‘Timstein’ and ‘Red Egyptian’ into genetic background of ‘Chinese Spring’ and their parents in a randomized complete block design with four replications under water-stress and non-stress conditions in a greenhouse at 2014. In addition, a F2 population obtained from crosses between Timstein and Chinese Spring was also included within the experiment. Significant differences were seen among substitution lines under the both conditions for all studied traits. B genome of Timstein series was more effective in controlling variances observed for biological yield than other genomes. In Red Egyptian series, genome comparisons demonstrated that D and B genome were more important in controlling the variances observed for grain yield and harvest index at non-stress and water-stress conditions, respectively. It was also determined that the genomes of these two substitution lines series did not have the same trend in controlling the variations observed for the studied traits. Stepwise regression analyses showed that yield components contributions for grain yield variance were not similar under the two conditions. So that, at non-stress condition biological yield and harvest index and at water-stress conditions the number of seeds and spikes explained a higher percentage of variations for grain yield. In general it was documented that biological yield and harvest index were entered into model in three cases out of four regression analyses and these two traits are the most stable traits in explaining the variance observed for grain yield.