Multi-environmental trial and stability study of Ethiopian sesame (Sesamum indicum L.) genotypes at Western Oromia

Sesame (Sesamum indicum L.) is the most important oil crop in the world. A multi-environmental yield trial is used to assess genotype-by-environment interaction for selecting superior genotypes. The current study was initiated to identify stable and high-yielding sesame genotypes. Accordingly, 16 sesame genotypes were evaluated in a randomized complete block design at six distinct environments. The additive main effects and multiplicative interaction (AMMI) and genotype plus genotype × environment interaction (GGE) biplots models were used to estimate the stability of the genotypes across test environments. The results of the combined analysis of variance showed that the genotypes, environments, and genotypes-by-environment interaction were highly significant (p < 0.001), which indicated the presence of genetic variability among tested sesame genotypes across environments. AMMI analysis of variance revealed highly significant (p < 0.001) variations among environments, genotypes, genotype × environment interaction, and four-interaction principal component analysis (IPCA). The first four interaction principal component axes (IPCAs; IPCA1, IPCA2, IPCA3, and IPCA4) were highly significant and contributed 43.55%, 30.60%, 20.66%, and 2.94% of the total genotype-by-environment interaction, respectively. G03 and G10 obtained the highest yield and were placed on a GGE biplot with a close-to-concentric circle, indicating wide adaptability to the tested environments and similar agroecology. Moreover, the genotypes showed bacterial blight tolerance in western Ethiopia. Hence, these two genotypes were selected as potential candidates for sesame genotypes that could be released in the tested environments.