Analysis of Genotype × Environment Interaction for Seed Yield in Winter Rapeseed Cultivars and Lines Using Multivariate Method of Additive Main Effects and Multiplicative Interaction

Evaluation of the different genotypes under different environmental conditions helps plant breeders in detecting stable and high-yielding genotypes. In this regard, 13 winter rapeseed cultivars and lines were evaluated in a randomized complete block design with three replications in six experimental field stations of cold and temperate regions of Iran (Isfahan, Hamedan, Karaj, Kermanshah, Khoy and Zarghan) during two cropping seasons. For analyzing genotype × environment interactions the multivariate method of additive main effects and multiplicative interaction (AMMI) was used. The Results of combined analysis of variance indicated that 50.26, 4.68 and 23.49 percent of total variation were related to the environment, genotype and genotype × environment interaction effects, respectively. The results showed that the first five principal components of AMMI were significant and described 85.4% of the variance of genotype × environment interaction. Biplot graph of mean seed yield and first interaction principle revealed that genotype G13 had a higher average seed yield than the overall mean yield and lowest value for first principle component. Therefore, this genotype was selected as a high-yielding and stable genotype. Also, Zarghan and Khoy indicated the strongest interactions and, hence, were recognized as the most ideal environments for distinguishing and discriminating winter rapeseed genotypes. The cluster analysis classified the studied environments in three groups. The presence of Isfahan, Hamedan and Zarghan locations each in a group indicates that these locations had the higher predictability and repeatability power compared to other locations. Genotype G13 with mean seed yield of 4086.02 kg ha-1 and a broad adaptability could be used for cultivation in cold and temperate regions of Iran.