Genotype by environment interaction and AMMI analysis of sesame (Sesamum indicum L.) genotypes at western Oromia of Ethiopia

Sesame is a significant oil seed crop due to its nutritional and economic value, serving as a major source of income and foreign exchange in many countries, particularly Ethiopia, which is a top global producer. However, genotype × environment interaction (GEI) significantly influences the seed yield to get stable and high-yielding genotypes. Therefore, this study aimed to evaluate the genotype × environment interaction, assess yield stability, and identify high yielding and widely adapted sesame genotypes across diverse environments in western Oromia, Ethiopia. The current study was conducted with 12 sesame genotypes in a randomized complete block design at six different environments. All yield and yield related data were collected analyzed using REML, AMMI, and GGE biplot analyses. The genotypes, environments, and genotypes by environment interaction were all highly significant ( p < 0.01) based on combined analysis of variance, indicating the existence of genetic variability among tested sesame genotypes across environments. AMMI analysis of variance revealed highly significant ( p < 0.01) variations among environments, genotypes and GxE interaction. The first two-interaction principal component analyses (IPCA1 and IPCA2) contributed 45.55% and 29.48% of the generated variation, respectively, and were very significant. BKC-047 (G2) produced the highest seed yield and was positioned close to the center of the concentric circles in the GGE biplot, indicating high mean performance, wide adaptability, and stability across the tested environments and similar agro-ecological conditions. In contrast, BK-005 (G6) exhibited superior performance in specific environments, suggesting specific adaptation rather than broad adaptation. Furthermore, both genotypes demonstrated tolerance to bacterial blight under the tested agro-ecological conditions. AMMI and GGE biplot analyses effectively characterized genotype × environment interactions and identified stable, high-yielding sesame genotypes. BKC-047 (G2) is recommended for variety verification trials because of its broad adaptation and stable performance across the tested environments and similar agro-ecological zones. BK-005 (G6) is recommended for variety verification trials in environments where it exhibited specific adaptation and superior yield performance. These genotypes are promising candidates for potential release following successful verification.