Vol. 11, Issue 12 (2022)

An attempt has been made in the present investigation entitled “Character association, divergence and genotype X environments interaction analysis in Indian mustard (Brassica juncea (L.) Czern & Coss) genotypes under microenvironments” to know genetic diversity and stability parameters of diverse genotypes during Rabi 2021-22 with three environments at the village Naugaya, Bharatpur, Rajasthan. Experimental material consisted of 20 Indian mustard genotypes under Randomized Complete Block Design and observation recorded for eight quantitative traits viz., Days to 50% flowering, Days to maturity, Plant height, Number of primary branches per plant, Number of secondary branches per pant, Number of siliquae on main raceme, biological yield per plant, Seed yield per plant. Analysis of variance showed genotypes were highly significant for all the traits in EI, EII and EIII. Magnitude of PCV% and GCV% for different traits revealed that the maximum amount of variability was found for number of secondary branches per plant in EII and EIII of Indian mustard. High heritability was observed for all traits viz., Days to 50% flowering, Days to maturity, Plant height (cm), Number of primary branches per plant, Number of secondary branches per plant, Number of siliquae on main raceme, biological yield and Seed yield per plant (g) in EI, EII and EII of Indian mustard. Significant and positive correlation was observed for seed yield per plant with number of primary branches per plant, number of secondary branches per plant, number of siliqua on main raceme and biological yield in all the environments. Path coefficient analysis revealed that number of siliquae on main raceme, number of primary branches per plant, number of secondary branches per plant, days to maturity and plant height had the highest positive direct effect on seed yield per plant. Percent contribution of individual traits towards the total divergence was found maximum for number of secondary branches per plant, days to 50% flowering showed contribution toward the divergence in all the environments. Genotypes were grouped into IV clusters in EI, XI clusters in EII IV clusters in and EIII. In EI, EII and EIII cluster I exhibited largest among all the clusters comprising of 17, 7 and 17 genotypes respectively. Intra cluster distance was recorded maximum for cluster I whereas three clusters viz., cluster II, III and cluster IV showed zero value in EI. The dendrogram constructed based on UPGMA (Unweighted Pair Group Method with Arithmetic Mean) between genotypes showed that 20 genotypes formed two clusters (cluster I and II). Cluster I encompassed only 1 genotype and Cluster II included remaining 19 genotypes. Analysis of variance carried out as per the model given by Ebrehart and Russell (1966) indicated that variance due to Env. + (G (varieties) x E) was significant for all the characters. The significant G (varieties) x E (linear) for the days to 50 per cent flowering, days to maturity, plant height (cm), primary branches per plant, secondary branches per plant, number of siliquas on main receme, biological yield per plant and seed yield per plant indicate divergent linear response to environmental changes.