Grain Yield Stability Analysis of Some Durum Wheat (Triticum durum Desf.) Genotypes Growing under Sub-humid Conditions

Abstract

Background: Assessment of yield stability of durum wheat growing under different environments has been an important issue for wheat breeder. More Information about phenotypic stability is useful for the selection of adapted and stable genotypes which are suitable for wider range of planting.Methods: To calculate the parametric and non-parametric index, we use the program STABILITYSOFT. The aim of this study is the selection of adapted and stable genotypes based on the use of parametric and non-parametric index.Result: The graphic distribution of the genotypes tested based on the relationship between the mean grain yield and regression coefficient (bi), proved that the suitable genotypes for the tested conditions are Bidi17, Wahbi and Gta dur. The values of deviation from regression (S²di) classified the genotype Waha, as the most desirable genotypes. The Association between Wricke’s ecovalence (Wi²) indice and the grain yield proved that the best genotype for growing under these conditions are Bidi17, Wahbi and Gta dur. In addition, the non-parametric index confirmed the results which are registered by the selection based on the parametric index. Thus, the genotypes Bidi17 and Wahbi are the most stable genotypes. The classification based on the use of the principal component analysis classified the genotypes Wahbi and Bidi17 in dynamic stability group with highest grain yield. Therefore, genotypes with b values close to 1 (Wahbi, b = 0.95 and Bidi17, b = 0.98) are preferred since it is indicative of wide adaptation (dynamic stability), provided their mean yield is over the general mean. Overall, the uses of the parametric and non-parametric index are very suitable tools to select adapted and stable genotypes under sub-humid conditions.