Application of GGE biplot analysis to evaluate grain yield stability of rainfed spring durum wheat genotypes and test locations by climatic factors in Iran

Grain yield stability is an important feature of crop breeding programs due mainly to the high annual variation in mean yield, particularly in arid and semi-arid areas. Conventional statistical models of stability analysis provide little or no insight into patterns of genotype × environment (GE) interaction, though the genotype plus GE (GGE) biplot method can more effectively account for the under GE interaction patterns. This study evaluated the yield stability of 20 spring durum wheat genotypes grown in five different warm locations in Iran across four cropping cycles (2009-2013) and used GGE biplot analysis to evaluate the yield stability of the genotypes and test locations by climatic factors. The combined analysis of variance revealed that the main effects of genotypes, locations, and years were significant, as well as the corresponding interaction effects. A polygon view of GGE biplot indicated that there were three winning genotypes (G10, G8, and G20) in three mega-environments for durum wheat in rainfed conditions. An ideal test location view of the GGL biplot showed that Gachsaran is the most desirable test location; genotype evaluation at this location maximized the observed genotypic variation among genotypes for durum wheat grain yield. Useof GGE biplots facilitated visual comparisons and identification of superior durum wheat genotypes for each target location. Genotype G10 was better than the other genotypes and is recommended for warm rainfed spring durum wheat growing areas of Iran.