Unraveling Trait Relationships and Their Direct and Indirect Contributions to Seed Yield of Sesame (Sesamum indicum L.) Genotypes

Abstract

Sesame is one of the oldest oilseed crops, valued not only for its traditional importance in food, culture and medicine, but also for its high oil content, superior nutritional quality and significant economic value. In this study, 20 advanced sesame genotypes along with standard checks were evaluated in a randomized block design (RBD) for understanding the relationships among traits and how they directly and indirectly influence seed yield using correlation and path analysis. The analysis of variance (ANOVA) revealed highly significant differences among genotypes for all traits, indicating the presence of substantial variability. The PCV values were observed higher than GCV for all traits, seed yield (GCV: 11.57%, PCV: 17.78%) and capsules per plant (GCV: 10.05%, PCV: 10.99%) showing comparatively higher variability, indicating scope for selection along with environmental influence. High heritability (broad-sense) was observed for plant height (92.18%) and capsules per plant (83.56%), coupled with high genetic advance as percent of mean (17.56% and 18.92%, respectively), suggesting additive gene action. Seed yield exhibited strong positive genotypic correlations with plant height and capsules per plant. Path analysis observed that test weight (0.875), plant height (0.777) and number of primary branches per plant (0.339) as the primary direct contributors to seed yield in sesame. Principal Component Analysis (PCA) showed that number of capsules per plant and seed yield are closely associated, indicating their strong contribution to yield, while plant height and test weight also showed positive relationships. These findings suggest that plant height, capsules per plant, primary branches per plant and test weight are reliable selection criteria for improving seed yield in sesame breeding programs.