Abstract
A full-diallel cross of five durum wheat genotypes[Simeto (1), Ofanto (2), Acsad 65 (3), Miman-9 (4) and CRAK-10 (5)] was made in the growing season 2010-2011 at the Research Field of the College of Agriculture, Salahaddin University in Erbil, Iraq. Grains of 20 F1s and their five parents were planted on 15 November 2011 in two separate experiments, rainfall (stress) and irrigated (non-stress) using a randomized complete block design with three replications in order to study the genetic properties of days to flowering, plant height, flag leaf area, spike length, no. of spikes/plant, no. of grains/spike, 1000-grain weight, biomass yield/plant, grain yield/plant and harvest index by using Griffing, Hayman and Jinks-Hayman approaches. The results revealed that some parents exhibited positive and high general combining ability, while some hybrids showed specific combining ability for the majority of these traits. Important role of additive genetic component (D) was found for days to flowering, flag leaf area spike length, no. of spikes/plant, no. of grains/spike and biomass yield/plant under stress conditions and days to flowering, spike length, no. of spikes/plant, 1000-grain weight, biomass yield/plant, grain yield/plant and harvest index under non-stress conditions.The non-additive component (H1) was found to be important for the genetic control of all the traits under stress and non-stress conditions excluding grain yield/plant under stress conditions. The average degree of dominance (H1/D) ½ was>1 for all traits in both cases. The narrow sense heritability Hn.s .was low for flag leaf area, moderate for no. of grains/spike and 1000-grain weight, high for remaining traits under stress conditions. While low for no. of grains/spike, moderate for days to flowering, flag leaf area and grain yield/plant, high for remaining traits under non-stress conditions.Under stress conditions high heterosis was exhibited by cross [1×4] for most traitswhile by cross [5×3]under non-stress conditions.It could be concluded that generated of these genotypes will serve for the breeders to develop high yielding of durum wheat under water stress und non-stress conditions by employing individual or mass selection breeding.
