Harnessing genetic variability, trait association, and GGE biplot-based stability for linseed (Linum usitatissimum L.) improvement under rainfed and irrigated conditions

Linseed ( Linum usitatissimum L.) is a vital oilseed and fiber crop with significant industrial and nutraceutical value. Despite its potential, linseed cultivation in India is limited by abiotic stresses, particularly under rainfed conditions. This study aimed to evaluate 27 linseed genotypes for genetic variability, trait correlations, and yield stability under irrigated and rainfed conditions across two growing seasons. Ten agro-morphological traits were assessed, revealing considerable variation across genotypes. High heritability and genetic advance were recorded for plant height, capsules per plant, and plant stand, indicating strong additive genetic control and suitability for selection. Conversely, traits such as days to maturity and test weight exhibited low heritability, reflecting environmental influence. Correlation analysis identified positive associations between seed yield and traits like plant stand and test weight, suggesting their utility as indirect selection criteria. Principal component analysis (PCA) indicated that seed yield, flowering time, and architectural traits contributed significantly to genetic divergence. Genotype + Genotype × environment biplot (GGE biplot) analysis highlighted genotypes RL-18101, RL-18117, and RL-18116 as high-yielding under irrigated conditions, while RL-18117 emerged as the most stable and desirable genotype across environments. These findings provide key insights for targeted breeding strategies to improve yield and stability in linseed, especially under variable environmental conditions. The study reinforces the importance of integrating multi-environment evaluation with genetic analysis for effective linseed improvement. • High heritability were recorded for plant height, capsules per plant, and plant stand. • Positive associations were observed between seed yield and plant stand and plant height. • Seed yield, flowering time, and architectural traits contributed significantly to genetic divergence. • Genotypes RL-18101, RL-18117, and RL-18116 emerged as high-yielding under irrigated conditions. • RL-18117 genotype emerged as the most stable and desirable genotype across environments.