Parameters of AMMI Model for Yield Stability Analysis in Durum Wheat

Th e improvement of new genotypes with acceptable yield stability in diff erent environments is an important issue in breeding programs. In order to study genotype × environment (GE) interaction and to determine the most stable durum wheat genotypes, fi eld experiments were conducted with 20 genotypes for three years (20072009). Results showed highly signifi cant GE interaction indicating the possibility of selection for the most stable genotypes. Th e AMMI (additive main eff ect and multiplicative interaction) analysis indicated that the fi rst fi ve axes were signifi cant based on F-test of Gollob while the other tests (FGH1 and FGH2) identifi ed fi rst three axes as signifi cant AMMI model components. Furthermore, according to FRatio test and cross validation results, only fi rst two axes were signifi cant. According to these distinct numbers of signifi cant axes, sixteen AMMI stability parameters plus ASV (AMMI stability value) were computed. Our results showed that EVand D-based parameters, displayed G7 and G8, SIPC-based parameters indicated G3 and G4 and AMGE-based parameters identifi ed G15 as the most stable genotypes. Genotypes G15 and G7 were the highest mean yielding genotypes and so they could be regarded as the most favorable durum wheat genotypes. Th e results of this investigation proved that the most of AMMI stability parameters are suitable indices for discriminating stable genotypes and AMGE-based parameters can detect highly seed yield genotypes with good stability.