Abstract

                                The experiment was conducted with six generations derived from five inter varietal crosses TMV 5 x KS99037(C1), TMV 5 x KS990812 (C2), TMV 5 x KS990813 (C3), TMV 5 x KS99153 (C4) and TMV 5 x Cordebergea (C5) involving six genotypes of sesame to study the components of variances and degree of dominance for different traits. The observations on days to first flowering, days to maturity, plant height, number of primary branches, number of capsules per plant, capsule length, number of seeds per capsule, 100 seed weight and seed yield per plant were recorded for the selected individual plants. The variances estimated from different generations were partitioned into different genetic components of variation. The degree of dominance was greater than unity in TMV 5 x KS99037 for days to maturity, in TMV 5 x KS990812 for days to first flowering, in TMV 5 x KS990813 for days to first flowering and days to maturity, in TMV 5 x Cordebergea for number of seeds per capsule which showed over dominance for the respective traits. Hence, it is suggested for adoption of heterosis breeding for these crosses in sesame. The cross TMV 5 x KS99037 for days to first flowering, number of branches per plant and oil content and TMV 5 x KS990813 for plant height and number of capsules per plant showed partial dominance for the respective traits. The recombination breeding followed by selection in the later generation will improve the respective traits. The traits, plant height, number of capsules per plant and 100 seed weight were largely controlled by both additive and dominance variance. The pedigree or recombination breeding followed by selection in later generations would improve these characters. The environmental variance for the characters days to maturity, number of branches per plant, number of capsules per plant, capsule length, number of seeds per capsule and 100 seed weight revealed that environment plays an important role for the expression of these traits.

Key words : Sesame, gene action, components of variance, additive and dominance