الفهرس 
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Abstract
The present study was carried out during the two seasons 2007/2008 and 2008/2009 using four crosses from bread wheat ( Triticum aestivum L.). These crosses were (Line1×Sakha93), (Line1×Sakha94), (Sakha 93×Gemmiza9) and (Sakha94× Gemmiza9). The basic six generations (P1, P2, F1, F2, BC1 and BC2) for the four crosses were planted in two experiments. The first experiment was irrigated with four irrigations (Normal treatment). The second one was irrigated with only two irrigations (Stress treatment). Each experiment was grown in a randomized complete block design using three replications. Finally, the important results indicated that : 1-The obtained date showed that Line 1 and Sakha 94 were the best parents for grain yield under both water treatments .So that, cross 2 (Line 1× Sakha 94) was the highest grain yield/plant under both water treatments. 2-Tolerance index and yield redaction ratio obtained that line 1 and Sakha 93 were the best tolerant parents and low sensitivity to water stress. The results indicated that cross 1 (Line1×Sakha 93) had low values at both tolerance index and yield redaction ratio at most of generations so that cross 1 was favored for water stress treatment. 3-Selection for most traits might be more effective in early generations for improving such traits in the four studied crosses, however, it would be better if it was delayed to later generations 4-Genetic advance under selection show high possible gain from selection for grain filling rate, number of spikes/plant and grain yield/plant. While, grain filling rate and number of spikes/plant had strong link with grain yield/plant so that it could be recommended to selection for these traits.