Evaluation of bread wheat genotypes under irrigated multi-environment conditions using GGE biplot analyses

Abstract

This research was carried out to determine stable genotypes, and investigate genotype environment interaction (GEI) effects on the grain yields of 9 bread wheat genotypes (5 cultivars, 4 advanced lines) across eight irrigated environments in the Central Anatolian Region, in 2002-2003 and 2003-2004 growing seasons. The experimental layout was a randomized complete block design with four replications. GGE biplot methodology was used to evaluate phenotypic stability in genotypes. GGE biplot analysis indicated that the effects of environments, genotypes and genotype environment (GE) were highly significant (P < 0.01). The first two principle component axes (PC1 and PC2) were significant (P < 0.01) and cumulatively contributed to 76.14\% of the total genotype by environment interactions. The biplot (PC1 versus mean grain yield) showed five groupings of genotypes: `Line-1' generally low yielding and unstable (high negative PC1 score); and `Line-3' was low yielding and moderately stable across environments (low positive PC1 score); `Katea-1', `Yildiz-98' and `Line-2' were high yielding, and stable (had low positive PC1 scores). `Konya-2002' was high yielding and moderately stable across environments (low negative PC1 score). For irrigated bread wheat genotypes grain yields were relatively stable at Haymana and Cumra, while grain yields obtained at Konya were unstable across both years. Besides, superior bread wheat genotypes selections with specific or broad adaptation were identified by a biplot generated using genotypic and environmental scores of the first two GGE biplot components (PCA1 and PCA2).