The genetic potential of onion ( <i>Allium cepa</i> <scp>L</scp> .) germplasm for enhancing productivity, adaptability, and sustainability in the current era of climate change

BACKGROUND: Understanding genotype × environment interaction is essential for developing stable, high-yielding onion cultivars under changing climatic conditions. This study evaluated 24 diverse onion (Allium cepa L.) germplasms across three different locations over 2 years following a randomized complete block design with three replications. Genetic variability, yield performance, and stability were assessed using an integrated analytical framework. RESULTS: Combined analysis of variance revealed significant effects of genotype, environment, and their interaction for yield and associated traits, indicating differential genotype responses. Substantial variability was observed; fresh yield showed strong positive associations with bulb diameter, individual bulb weight, and bulbing index. Multivariate analyses, including principal component analysis and the multi-trait genotype-ideotype distance index (MGIDI), identified genotypes with superior trait combinations. Stability analysis using additive main effects and multiplicative interaction (AMMI), genotype main effects plus genotype × environment interaction (GGE) biplot, and complementary numerical parameters revealed consistent performance of a subset of genotypes across environments. Notably, Ac Bog 413, Ac Bog 415, Ac Bog 428, Ac Gaz 379, and BARI Piaz-4 were identified as high-yielding and stable across multiple analytical approaches. CONCLUSION: Although some genotypes exhibited moderate yield, their high stability indicates potential as donor parents for adaptive traits in breeding programs. The integration of yield performance, trait association, multivariate indices, and stability analyses provides a robust framework for selecting climate-resilient onion genotypes. © 2026 Society of Chemical Industry.