Brassica rapa is an important oilseed crop in Pakistan. It is a rich source of oil and contains 40%–46% oil. In addition, its meal has 38%–40% protein. Given their high levels of erucic acid and glucosinolate, mustard and rapeseed oil is unhealthy as regular cooking oil. A dire need to exploit the genetic variability of rapeseed germplasm is necessary to improve the performance of cultivars. The line × tester analysis helped estimate various types of gene actions that are important to quantitative traits. The key to successful research is selecting suitable lines and testers and designing good mating patterns. Choosing and developing genotypes with high yield and fatty acid profiles are the major concern of rapeseed breeders. The current research on hybridization and evaluation of Brassica rapa accessions sought better harvest and its related traits from the selected germplasm. The combining ability effects determination used line × tester analysis in rapeseed. The accessions’ variability analysis exhibited extremely significant differences in yield and related traits. Recorded data for different morphological and yield-related qualities provided days till 50% flowering, the number of major branches per plant, and the number of secondary branches per plant had positive and significant general combining ability estimates, and all yield-related variables had extremely notable specific combining ability estimates. All the yield-related characteristics displayed a favorable and substantial connection in the examined germplasm. Among the lines, 28244, 40980, and 40981 occurred to be the best general combiners showing the additive gene action. The cross combinations, 40977 × 26283, 40979 × 26283, and 40981 × 26283, indicated significant specific combining ability effects, which showed the non-additive genetic effects of total variance due to the dominance and/or epistasis. The results suggested that the research material used in the remarkable study can benefit by improving yield and fatty acids-related components and can further enhance upcoming breeding programs based on strong particular combining ability impacts.

Keywords: additive, non-additive, line × tester, glucosinolate, erucic acid, protein, rapeseed, analysis of variance

Key findings: Among 150 accessions screened concerning yield and their related traits, the accessions 40977 × 26283, 40979 × 26283, and 40981 × 26283 were the best cross combinations for yield and fatty acids-related components. These accessions will benefit future breeding programs for harvest enhancement along with its quality components.