Determination of Yield Stability in Durum Wheat Genotypes under Rainfed and Supplementary Irrigation Conditions

Tests were done to determine high-yielding and stable durum wheat genotypes. An experiment was set up as a RCBD (Randomized Complete Block Design) with three replications on 17 advanced durum wheat genotypes under rainfed and supplementary irrigation conditions in the cropping seasons of 2011-13. Combined analysis of variance indicated that environment main effect accounted for 70.09% of total yield variation; and effects of genotype and Genotype×Environment Interaction (GEI) accounted for 2.95 and 10.71%, respectively. Results indicated remarkable difference in genotypes response across environments. G×E interaction was analyzed following Additive Main effects and Multiplicative Interaction (AMMI) model. The first two interaction Principal Component Axes (IPCA1 and IPCA2) explained 53.75 and 36.99% of total interaction effects, respectively. Based on the AMMI model, AMMI Stability Value (ASV) and Genotype Selection Index (GSI), genotypes G11, G8, and G14 were selected for all environments. According to the AMMI2 biplot, the G15, G16 and G17 exhibited specific adaptation with rainfed (E1) and irrigation (E2) environments. G3 and G4 displayed specific adaptation with rainfed (E3) environment and G10, G9, G1, and G12 indicated specific adaptability with irrigation (E4) environment. The E3 had high discrimination ability, so, this environment was considered sufficient for making genotypes recommendation. Results of this investigation illustrate that the AMMI stability parameters are suitable for characterizing stable genotypes and that the GSI parameter can detect genotypes with high grain yield and good stability for plant breeding research in durum wheat.