Dissecting genetic variability and yield trait interplay in a diversity panel of Brassica juncea (L.) Czern. & Coss.

Enhancing yield and adaptability in Brassica juncea (L.) Czern. & Coss. requires a clear understanding of agro-morphological variability and genetic control of key traits under diverse environmental conditions. This study evaluated 150 diverse genotypes along with three checks at Ludhiana and Abohar during 2021–22 and 2022–23 (two locations × two years) using augmented design. Significant phenotypic variation was observed across environments, particularly for traits such as number of primary branches (PB), number of siliquae per plant (NOS) and seed yield per plant (SY/P). High heritability along with high genetic advance for traits including days to 50 % flowering (DF50), plant height (PH), main shoot length (MSL) and SY/P suggest a predominance of additive genetic effects and strong potential for selection gains. In contrast, traits like days to maturity (DM) and silique length (SL) exhibited moderate heritability and greater environmental sensitivity, indicating the need for location-specific breeding strategies. Genotype-by-environment interactions were significant for most traits, reinforcing the importance of multi-environment evaluation. Path coefficient analysis revealed that MSL, SL and seeds per silique (S/S) exerted strong direct effects on SY/P, offering valuable secondary selection criteria. The integration of genetic parameter estimation with path analysis provides a robust framework for identifying high-performing, stable genotypes and optimizing trait combinations. These findings support the development of targeted, environment-specific breeding programs aimed at improving yield potential and resilience in Indian mustard.