Analysis of stability and adaptability of grain yield in durum wheat geneotypes

The objectives of this study were to analyze genotype by environment (GE) interactions on the grain yields of 18 promising durum wheat lines selected from joint project between Iran and ICARDA along with two national durum (Zardak) and bread wheat (Sardari) checks by the additive main effects and multiplicative interaction (AMMI) model and to evaluate genotype (G)، environment (E) and GE interactions using statistics parameters i. e.، AMMI stability value (ASV) and ecovalence (W2). The trials were conducted at four locations، representative for multi-location durum yield trials، in Iran under rain-fed (unfavorable) and supplemental irrigation (favorable) conditions for three successive cropping seasons (2005-07). Main effects due to E، G and GE interaction as well as three first interaction principal component axes (IPCA 1-3) were found to be significant (P <0. 01). AMMI biplots were able to distinguish genotypes، with wide and specific adaptation، and environments، with high and low genotype discrimination ability. The genotype G9 with the highest mean yield was to be most stable genotype، while the G16، G17 and G18 with the highest contribution to GE interaction were to be most instable. The results of recommended genotypes based on AMMI analysis showed the G15، G9 and G12 were highly adapted to rain-fed and supplemental irrigation conditions of Kermanshah. The all genotypes from ICARDA (G16، G17، G18) were highly adapted to both rain-fed and irrigation conditions of Ilam. The best genotypes for rain-fed condition of Maragheh were G15 and G1 while the G15 and G16 were the best for supplemental irrigation condition. The genotypes G15، G9 and G1 were the best for Shirvan. In this study the G15 was the genotype with the best adaptation in three locations of Sararood، Maragheh and Shirvan.