Emmer wheat (Triticum turgidum ssp. dicoccum) is an important gene source for wheat improvement but less studied in crosses with its descendant species durum (Triticum turgidum ssp. durum), especially in respect to the type of genetic components, intergenic interactions and the genetic mechanisms governing responses to drought. In this study, generation means analysis was performed using F1, F2, BC1P1 and BC1P2 from two different crosses of emmer × durum. Seeds were planted in a RCBD design with three replications under two water regimes. Results showed that there was a highly considerable difference between generations for all studied traits. The presence of significant mean parameter for all the traits, indicated the quantitative inheritance of the traits. Estimating the number of effective genes, polygenic control of the traits were confirmed. In moisture stress condition, epistatic effect for grain yield and yield-related traits illustrated the importance of epistasis in plant adaptation and performance stability. The additive × additive effect, which is fixable, was remarkable in both crosses. Under both water regimes, narrow-sense heritability was relatively high and estimates of gain from selection were positive for most of the traits. Among generations studied, the backcrosses were superior for drought tolerant indices. Based on the results, emmer wheat seems to have genetic potential for durum improvement.