GENE ACTION AND COMBINING ABILITY STUDY IN SESAME

Abstract

The study of gene action and combining ability have been conducted in 28 F1 cross combinations along with eight parents in 8x8 half-diallel scheme following Griffing’s Approach for 14 morphoeconomic traits including seed yield and oil content in sesame. The general combining ability (GCA) and specific combining ability (SCA) component of variation were significant for parents and crosses respectively for all characters except internode length for GCA indicating role of both additive and nonadditive gene action. However, higher proportion of SCA variance (?2 sca) than GCA variance (?2 gca) revealed preponderance of non-additive gene action for all characters except capsule length and capsule width under study. Further, variance due to dominance played a significant role than additive variance in all traits except capsule width and 100-seed weight. Nirmala is considered as the best general combiner owing to its higher estimate of gca effects for yield per plant, for days to maturity, plant height, branches per plant, capsules per plant, seeds per capsule, capsule length and 100-seed weight. Among cross combinations; Rama × GT-10, AT-382 × Krishna, AT-382 × Nirmala, Krishna × Nirmala, Krishna × Uma, Nirmala × Prachi and Prachi × Uma showed significantly higher sca effect for seed yield per plant in the desired direction indicating their merit for recovery of transgressive segregants for higher productivity following reciprocal recurrent selection.