Identification of key yield determinants in sesame through multivariate analysis of F2 and F3 populations

Abstract

The research was conducted to evaluate the F₂ and F₃ segregating populations of inter-varietal crosses in sesame for selecting superior segregants.  The experiment involved F₂ generation of three superior crosses of sesame, namely; Thilak x Ayali 1, Thilathara x Ayali 2 and Thilak x Ayali 5. The seeds of the selected superior F₂ lines namely; TA1-5, TA5-2, TA5-4, TA5-5 and TA5-32 were advanced to F₃ generation, which was raised in a compact family block design. Principal Component Analysis was carried out to identify the key traits influencing yield and genetic divergence. In PC1, traits such as capsule length, capsule width, number of seeds per capsule, plant height, and seed yield were identified as critical determinants, while in PC2, crop duration traits like days to maturity and first flowering were observed to be critical. Segregants such as TA5-2, TA5-4, and TA5-32 stood out for their promising yield traits and genetic variability, demonstrating the practical utility of PCA in breeding efforts. Regression analysis of both F₂ and F₃ populations revealed that the number of capsules per plant was the most influential factor, with capsule width, number of seeds per capsule, and plant height also contributing substantially to yield variability.