Genotype × Environment Interactions Effects on Grain Yield in Chitti Bean Genotypes

Existence of genotype × environment interaction for quantitative traits such as grain yield can limit the selection of superior genotypes for the development of improved cultivars. In order to calculate the interaction of genotype × environment, breeders evaluate genotypes in several environments to identify genotypes with high yield and stability. This experiment was performed to investigate the interaction of genotype in the environment on 11 bean genotypes using parametric and nonparametric methods and GGE bioplot model to evaluate genotypes and environments, determine the relationship between genotypes and environments and identify the ideal genotype.   

In this experiment, 9 lines of pinto beans along with Ghaffar cultivars and Cos16 lines (11 lines in total) were performed in a randomized complete block design with three replications in order to achieve high yield and marketable bean cultivars. Parametric and non-parametric methods were used to select stable genotypes with high yield and GGE bioplot analysis was used to select superior genotypes that are compatible with regional environments.

There was a significant interaction between genotype and environment, indicating significant differences in the response of genotypes to different environments of the experiment. In parametric methods G4, G8, G9 and to some extent G2 genotypes and in nonparametric methods G2, G8, G3, G4 and to some extent G9 genotypes were introduced as stable cultivars. Biplot analysis showed that G1 genotype in Zanjan in first and Second years and G2 genotype in Khomein n first and second environments showed the highest yield. G11 and G7 genotypes with the longest distance to the ATC line had low yield and low yield stability. None of the genotypes were found to be desirable genotypes with average yield and high yield stability, but G2 genotype and later, G4 genotype was a short distance from the ideal genotype. None of the studied environments is close to the ideal environment and therefore none of them can be considered as representative of environments for genotype segregation.

Zanjan in first and Second years and G2 genotype in Khomein n first and second environments have the highest yield. No ideal genotypes were observed, but two genotypes, G1 and G4, can be introduced as superior genotypes.