Multi-environment trial analysis on barley (Hordeum vulgare L.) genotypes using AMMI, GGE biplot, and multi-trait stability index

Genotype by environment interaction (GEI) is central to comprehending the stable performance of genotypes through the application of contemporary statistical techniques. The objective of this experiment is to investigate the nature and magnitude of genotype by environment interaction and identify barley genotypes combining desirable and stable pheno-agronomic traits. The experiment was conducted in six environments at Holetta, Chefe Donsa, and Arsi Negelle in a randomized complete block design (RCBD) with three replications. Combined AMMI-ANOVA for grain yield and likelihood test ratio for pheno-agronomic traits revealed GEI had a substantial impact on the studied traits at ( p < 0.001 ). The first two AMMI interaction principal components explained 76.23% of the total and 72.19% of the signal component of the interaction, justifying the reliability of evaluating the stability of the genotypes based on these two interaction components. AMMI analysis through AMMI1, AMMI2, AMMI Stability Value, and Genotype Stability index demonstrated that G1, G3, and G19 were the most desirable genotypes. The GGE biplot also identified G1, G3, and G9 with little to no contribution to the GEI. The same analysis identified two mega-environments, Holetta-Chefe Donsa and Arsi Negelle, where G4 and G5; and G13 were winning, respectively. This justifies that G-4 and G-5 were found to be specifically adapted and are recommended for the Holetta type of environment, and G-13 for the Arsi Negelle type of environment. Multi-trait stability analysis revealed a positive WAASBY (superiority index) selection differential, with G7, G5, and G4 being the closest to the ideotype. Therefore, based on the results from all three statistical models, we recommend the ideal genotypes of barley (G1 and G7) for wider adaptation and hence commercial cultivation.