TRAIT-BASED GENETIC VARIABILITY ANALYSIS IN BRASSICA NAPUS FOR YIELD AND QUALITY IMPROVEMENT

Abstract

Background: Brassica napus represents a major oilseed crop globally and locally, belonging to the economically significant family Brassicaceae. As the world’s third most important source of edible oil after soybean and cotton, rapeseed and mustard play a critical role in supplementing domestic oil requirements. Understanding the extent of genetic variability within available germplasm is essential for strengthening breeding pipelines, improving productivity, and enhancing oil quality traits needed to meet growing nutritional and industrial demands.

Objective: To assess the genetic variability among Brassica napus genotypes based on morphological and quality-related traits for effective selection and future breeding application.

Methods: Ten genotypes of Brassica napus were evaluated under a randomized complete block design with three replications. Data were recorded for plant height, shoot diameter, days to 50% flowering, days to maturity, main raceme length, silique length, number of seeds per silique, siliques per main branch, thousand-seed weight, seed yield, oil content, protein content, erucic acid, and glucosinolate concentration. Statistical analyses included analysis of variance (ANOVA) to detect significant differences, followed by LSD tests for pairwise mean comparisons. All procedures ensured accurate assessment of trait variability and genotype performance.

Results: Highly significant differences (p < 0.05–0.001) were detected across all traits. Main raceme length ranged from 91.4 to 129.8 cm, silique length from 8.14 to 11.78 cm, and seeds per silique from 19 to 27.6, with Dunkled showing the highest values. Seed yield varied between 1252 and 1764 kg/ha. Genotype RBN-63 possessed the lowest erucic acid (0.42%) and glucosinolates (119 µmol/g) along with high protein content (23.5%), whereas RBN-72 exhibited the highest oil content (45%). Coefficients of variation remained low to moderate, confirming stable trait expression.

Conclusion: The study identified substantial genetic variability among the genotypes, enabling meaningful selection for breeding. RBN-63 and RBN-72 were most promising for enhancing oil quality and protein content, while Dunkled showed superiority in yield-contributing traits. These findings offer valuable direction for developing high-yielding, high-quality Brassica napus cultivars.