AMMI analysis of phenotypic stability in chickpea genotypes over stress and non-stress environments

The genotype × environment interaction has a direct effect on genotypes stability and adaptability in different environmental conditions . In this sense, plant breeders look for genotypes that have general adaptability, or they look for genotypes that have specific adaptability for specific environments. In this regard, 20 chickpea genotypes were used in a randomized complete block design with three replications under two rainfed and irrigated conditions for 4 consecutive growing seasons (2008-2011). AMMI analysis showed that chickpea grain yield was significantly (p<0.01) affected by environments (E), genotypes (G) and genotype × environment interaction (GEI) indicating the presence of genetic variation and possible selection of stable entries. 81.62% of the total sum of squares was justified by environmental fluctuations exhibiting that the environments were diverse, with large differences among environmental means causing most of the variation in grain yield. GEI was further partitioned by principal component analysis. The first three multiplicative axis terms (PCA1, PCA2 and PCA3) explained 48.37, 25.54and 16.17% (90.08%) of GEI sum of squares, respectively. According to AMMI1 biplot G2, G8, G11, G14 and G19 (adaptive group 1) exhibited specific adaptability for rainfed environments: E3, E5 and E7 with grain yield less than mean and positive interaction. Genotypes G4, G5, G6, G12, G16 and G17 (adaptive group 2) revealed specific adaptation for irrigated environments E4, E6 and E8 with high grain yield more than mean yield and positive interaction. The accessions G3, G7, G13, G18 and G18 (adaptive group 3) on the IPCA= 0 showed stability and general adaptability with grain yield close to mean yield and negligible interaction. The entries G1, G9 and G10 (adaptive group 4) were identified with specific adaptability for irrigated environment E2 with positive interaction and G20 (adaptive group 5) was screened with general adaptability for stress and non-stress environments (close to IPCA = 0) with high grain yield more than mean yield and negligible interaction.