Genetic Variability and Improvement in Indian Mustard (Brassica juncea L.)

Abstract

Aims: The study aimed to assess genetic variability, heritability, and trait associations in Indian mustard (Brassica juncea L.) genotypes to identify promising lines and reliable selection indices for yield improvement under the agro-climatic conditions of Prayagraj. Study Design: The experiment was conducted using a Randomized Block Design (RBD) with 13 genotypes, including a check, across three replications. Place and Duration of Study: Main Experimental Station, Prof. Rajendra Singh (Rajju Bhaiya) University, Prayagraj, during the Rabi season 2024–25. Methodology: Thirteen genotypes of Indian mustard were evaluated in 39 plots with recommended spacing (45 × 10 cm) and fertilizer application (N:P:K:: 60:30:20). Observations were recorded on days to 50% flowering, days to maturity, plant height, primary and secondary branches, siliqua length, and siliquae per plant. Data were analyzed using ANOVA, estimates of genetic variability (GCV, PCV), heritability, genetic advance, correlation, and path coefficient analysis. Results: Analysis of variance revealed highly significant differences among genotypes for all traits, confirming ample genetic variability. Chetak (V1) exhibited early flowering (42.5 days), tallest plants (168.5 cm), maximum primary branches (6.1), longest siliquae (6.4 cm), and highest siliquae per plant (156.3), along with early maturity (116.2 days). Varuna T-59 (V9) and Shriram 1666 (V2) performed consistently well, while Sonalika (V6) and Black Gold (V7) showed moderate performance. Correlation and path coefficient analyses identified siliquae per plant, branching traits, and plant height as the most influential yield-contributing traits. High heritability with high genetic advance in siliquae per plant and branching traits suggested additive gene action, favoring direct selection. Conclusion: The study confirmed significant variability among mustard genotypes, with siliquae per plant, primary branches, and secondary branches as dependable selection indices for yield improvement. Chetak, Varuna T-59, and Shriram 1666 were identified as promising genotypes for breeding and direct cultivation, offering potential to bridge India’s edible oil yield gap.