This study was conducted to evaluate the genetically effective traits that related to drought tolernace using 14 bread wheat lines and cultivars where in previous experiment clusterd into two resistant and susceptible groups under non-stress and stress conditions using randomized complete block design replicated three times. The combined analysis based on north carolina desing II for studied triats in F1 generation revealed that the genotypice effect of male parents in two conditions, drought and irrigated, was significant for all traits with the exception of grain yield components including number of grain per spike and plant. The general combining ability (GCA) effects of cultivars were changed with decreasing of water availability. For most of the traits, the GCA × environment effect was significant. The estimates of narrow-sense heritability in two different moisture treatments revealed greater estimates for non stress than drought stress conditions due to genotype × environment interactions. The results revealed that for effectiveness of breeding program in drought stress, selection can be made under both full irrigated and water stress conditions. Harvest Index be suggested as powerful trait for screening of genotypes for drought stress tolerance.
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