Abstract: Heterosis, combining ability and reciprocal effects in a full diallel set of 6 varieties ( 2 genotypic male sterile lines, ms- 1 , ms- 2 , 2 exotic varieties: Danbackggae, Sindos 64 and 2 local varieties: Yuzhi No. 1 , 86-1) were studied in 1989. F1s from ms-2 , 2 × danbackggae, Danbackggae × Yuzhi No. 1 and Danbackggae ×ms- 2 displayed the highest heterosis, their yield surpassed the local variety Yuzhi No. 1 by 155.02%, 135.87% and 117.93%, respectively. The variances for general combining ability, special combining ability and reciprocal effect in 9 characters (plant height, height of first capsule, length of the main fruit axis, numbers of branch, capsules/plant, seeds/capsule, 1 000 seed weight and yield/plant) except the special combining ability of flowering period length, were all highly significant. It indicated the influence of both additive and non-additive gene actions. The higher ratio of σ2S:σ2g in the length of main fruit axis, seeds/capsule, 1 000 seed weight and yield/plant suggested the predominance of non-additive gene action in these characters.

Key words: Sesame, Heterosis, Combining ability, Reciprocal effect