Grain yield stability analysis for oat (Avena sativa L.) genotypes using additive main effects and multiplicative interactions model under different environments in Ethiopia

The performance of oat genotypes usually varies across environments due to variations in growing environments and the existence of genotype by environment interaction (GEI) complicates the selection process. In this study, twenty-four oat genotypes were assessed for grain yield and yield components in nine environments using randomized complete bock design (RCBD) with three replications in 2020/2021 cropping season. Hence, a GEI study was performed using additive main effects and multiplicative interactions (AMMI) analysis model to identify high grain yielding and stable genotypes. The AMMI analysis of variance for grain yield showed significant variation for genotype, environment and GEI effects and the environment's main effect was a predominant source of variation (44.62%) followed by genotype (28.84%) and their interactions (26.54%). The first two interaction principal component axes of AMMI were significant and cumulatively explained 63.96% of the total GEI variance. The environments located far from the biplot origin based on the AMMI-1 and AMMI-2 analyses were E2, E6, E5, E3, and E7 indicating these environments had high discriminating power and more contribution to GEI compared to other environments. Among the studied genotypes, G8, G17, G12, G19, G5, G14, G11, G22, G16, and G4 had mean grain yield above the grand mean. The result of stability analysis obtained from the AMMI-2 analysis was more accurate than the AMMI-1. Accordingly, genotypes which had mean grain yield above the grand mean and relatively stable performance were G4, G11, G12, G22, G14, G8, and G17. However, G4, G11, G12, and G14 were released varieties while G8, G17, and G22 have not been yet released. Therefore, G8 and G17 were selected for verification and commercial production in oat growing areas of Ethiopia.