Exploring Genetic Variability and Mutational Parameters for Selection toward Combined Improvement of Stress Resilience and Nutritional Composition in Mustard (Brassica juncea L.)
Harsh Kumar
Department of Genetics and Plant Breeding, Department of Soil Science and Agricultural Chemistry, Faculty of Agriculture, Prof. Rajendra Singh (Rajju Bhaiya) University, Prayagraj, Uttar Pradesh (211010), India.
Divya Singh
*
Department of Genetics and Plant Breeding, Department of Soil Science and Agricultural Chemistry, Faculty of Agriculture, Prof. Rajendra Singh (Rajju Bhaiya) University, Prayagraj, Uttar Pradesh (211010), India.
*Author to whom correspondence should be addressed.
Abstract
Background: Indian mustard (Brassica juncea L.) is one of the most important oilseed crops, contributing significantly to edible oil production and nutritional security. However, its productivity and quality are frequently constrained by abiotic stresses, necessitating the identification of genetically diverse and stress-resilient genotypes for sustainable crop improvement. The present investigation was conducted during the Rabi 2025–2026 season at the Department of Genetics and Plant Breeding, Prof. Rajendra Singh (Rajju Bhaiya) University, Prayagraj, India. Ten mustard genotypes, comprising nine test entries and one check variety, were evaluated in a Randomised Complete Block Design (RCBD) with three replications. Observations were recorded for growth, yield, quality, physiological, and stress tolerance traits. Genetic variability was assessed through analysis of variance, genotypic and phenotypic coefficients of variation, heritability, genetic advance, correlation, and path coefficient analyses. Significant (P ≤ 0.01) genetic variation was observed among the genotypes for all studied traits, indicating substantial scope for genetic improvement. Genotype G₉ consistently exhibited superior performance for growth, yield, nutritional quality, physiological efficiency, and antioxidant activity, recording the highest seed yield (19.33 q ha⁻¹), oil content (45.48%), protein content (23.05%), oil yield (651.25 kg ha⁻¹), relative water content (85.05%), membrane stability index (68.05%), proline accumulation, catalase activity, and peroxidase activity, while exhibiting the lowest glucosinolate content (22.80 µmol g⁻¹). Genotype G₆ ranked second for most agronomic and physiological traits. High heritability coupled with high genetic advance was observed for seed yield, biological yield, oil yield, branching traits, and antioxidant enzyme activities, suggesting the predominance of additive gene action. Correlation and path coefficient analyses identified biological yield, number of siliquae per plant, test weight, oil content, relative water content, membrane stability index, and antioxidant enzyme activities as major contributors to seed yield and stress resilience. The study demonstrated considerable genetic variability among the evaluated mustard genotypes and identified G₉, followed by G₆ and G₄, as superior genotypes combining high productivity, improved nutritional quality, and enhanced stress tolerance. These genotypes represent valuable genetic resources for breeding programmes aimed at developing climate-resilient, high-yielding, and nutritionally superior mustard cultivars.
Keywords: Brassica juncea, genetic variability, heritability, genetic advance, seed yield, nutritional quality, physiological traits, antioxidant enzymes, stress resilience, path coefficient analysis