Evaluation of phenotypic stability in bread wheat genotypes using GGE-biplot

ABSTRACT: The objective of this study was to explore the effect of genotype (G) and genotype × environment interaction (GEI) on grain yield of 16 bread wheat genotypes (Triticum aestivum L.) in five different environments. Yield data were analyzed using the GGE biplot method. Environment (E) explained 59.39% of the total variation, whereas G and GEI captured 9.39% and 14.34%, respectively. The first 2 principal components (PC1 and PC2) were used to create a 2-dimensional GGE biplot and explained 44.3% and 24.5% of GGE sum of squares (SS), respectively. Collective analysis of the biplots suggested three bread wheat mega-environments in Ilam Province. The first mega-environment contained environments: E2 with genotypes B2 and B7. Genotype B9 gave the highest performance in environment E1 and E3 and genotypes B8, B9, B3 and B2 revealed the highest performance in environments E4 and E5. Genotypes B9, B8, B3 and B2 exhibited the highest mean yield and genotypes B6 and B16 displayed the poorest mean yield. The highest stability was attributed to genotypes B8, B10, B16, B1 and B11. On the other hand, E3 and E5 were the best representative of the overall environments and the most powerful to discriminate genotypes performance.