Heterosis and combining ability studies in sesame (Sesamum indicum L.)

Abstract

A line × tester analysis was carried out in Sesame (Sesamum indicum L. ) with four lines viz., VRI 3, SVPR 1, TMV 6, and TMV 7 and six testers viz., Thilathara, Thilak, TKG 55, RT 125, RT 127 and Thilottama. A total of 24 cross combinations were made and ten biometrical characters viz., days to 50 % flowering, height to first capsule, plant height, the number of primary branches, the number of capsules per plant, the number of capsules on main stem, capsule length, days to maturity, 1000 seed weight and seed yield per plant were recorded and analysed for combining ability and heterosis. In this present investigation, the variance due to SCA was higher than the variance due to GCA, which indicates that the inheritance of seed yield/plant is governed by non-additive gene action. Combining ability was analysed based on gca and sca effects. VRI 3 was the best general combiner among lines and among testers Thilathara was the best general combiner. The sca effects showed that seven hybrids viz., VRI 3 × Thilak, VRI 3 × RT 127, VRI 3 × Thilottama, SVPR 1 × Thilathara, TMV 6 × Thilathara, TMV 7 × TKG 55 and TMV 7 × RT 125 exhibited significant and positive values and these crosses can be evaluated further in advanced generations. Heterosis over standard parent was estimated and the highest positive significant heterosis for seed yield per plant was registered by the cross TMV 6 × Thilathara (39.32 %) followed by VRI 3 × Thilottama (21.41 %). Key wordsSesame, nature of gene action, gca effects and sca effects, heterosis