Stability Evaluation of Bread Wheat Genotypes Under Varying Environments by Ammi Model

Abstract

Stable and high yield varieties identification under various conditions prior to release as a variety is the main steps for breeding program. In order to exploit narrow and broad adaptability of genotypes and assess their effects, environment and GE interaction, 12 spring bread wheat genotypes were grown at four various experimental locations during 2013-14 and 2014-15 growing seasons. The stability and superiority of genotypes were identified by the AMMI (additive main effect and multiplicative interaction) and GGE (genotype, genotype x environment) biplot analysis. The AMMI analysis showed that the variance of genotype, environment and GE interaction were significant and the major treatment sum of squares were significantly affected by environments (85.47%), genotypes (8.51%) and GE interaction (6.07%). On the other hand, the first principal component axes (PCA 1) distributed to the complete interaction as 62.56%, and the second PCA 2 axes 37.44%. The GGE bi-plot analysis indicated that the total variation PC (principle component) was 83.09%, and PC1 was accounted as 63.69%, PC2 only 19.40%. The AMMI analysis showed that C11 was quite stable as well as the highest yielder among test genotypes, while C7 and C8 were unstable and low yielding across environments. The GGE biplot indicated that it was detected in two mega-environments, and the first mega-environment covered three environment (E1, E2 and E3), and the second mega-environment covered only E4. The genotypes C11 and C12 remained superior under ME I, while genotypes C1, C3 and C5 were for ME II. Among the genotypes, the genotype C1 may be recommended to be developed and released as an approved cultivar for being comparatively more stable and the highest yielder. Therefore the AMMI and GGE biplot models have an opportunity to determine the best genotypes under multiple environments considering on adaptability and stability concentrating on overall performance for screening superior genotypes.