Heterosis breeding is one of the most efficient tools to exploit the heterotic response for various useful traits. The Line × Tester mating design was undertaken with seven lines and three testers were evaluated along with twenty one hybrids in randomized block design to estimate the magnitude of heterosis for yield and its yield contributing characters. The best way to utilize heterosis in crop is to generate F1 hybrids having maximum heterozygocity, thereby facilitating the identification and selection of hybrid vigor. The positive significant standard heterosis for fruit yield per plant was maximum with L3 × T1 (28.94%) followed by L7 × T3 (15.73%) and L7 × T1 (15.10%) respectively. Some of the promising hybrids have showed desirable heterosis for plant height, number of fruits per plant,1000 seed weight, seedling shoot length, seedling root length and seedling dry weight.

Five improved varieties of linseed namely, Meera, Shekhar, T-397, KL-221 and JLS-9 were crossed to obtain six F 1 s and F 1 s were selfed to get F 2 s. The estimates of heterosis revealed that none of the cross exhibited significant heterosis for all the characters over mid parent, better parent and check variety. The degree and direction of heterotic response varied not only from character to character but also from cross to cross. In general, considerable amount of significant desirable heterosis over mid parent, better parent and check variety were observed for few characters under study. Inbreeding depression in F 2 generation was estimated for all the characters and it was observed positively significant for seed yield per plant, stearic acid content, oleic acid content, linolenic acid content, linoleic acid content, palmitic acid content, primary branches per plant, capsule diameter, number of capsules per plant revealed significant positive inbreeding depression indicating detoriation in their performance in next generation.

The present studies were carried out with a set of eight varieties of linseed and their twenty eight F 1 's obtained through diallel crossing excluding reciprocals. The eight parents and their 28 F 1 s were grown in a randomised block design during Rabi season of 2012 and studied for fifteen quantitative and qualitative characters. The analysis of variance showed highly significant differences among the genotypes for all the characters studied except days to maturity in F 1 s. The genetic coefficient of variance was high in number of capsules per plant, linolenic acid content in F 1 s. The highest value of heritability was observed in linoleic acid content among parents whereas among crosses it was the highest in case of linolenic acid. Highest genetic advance was exhibited by number of capsules per plant in case of both parents and crosses. Genetic advance expressed as per cent of mean was the highest in steric acid per cent for parent and seed yield per plant for crosses in F 1 s. The traits with high heritability and high genetic advance may be subjected to mass or progeny or family selection or any selection scheme, aimed at exploiting additive (fixable) genetic variance, a widely adapted genotype can be developed, possessing good quality and high productivity.

The present investigation was carried out in sesame involving 7 lines and 3 testers to identify the nature of gene action, combining ability and heterosis in association with yield and its component traits in sesame during December 2017 -March 2019. The parents were mated in the Line×Tester method. The variance due to SCA was higher than the corresponding variance due to GCA for all the characters indicating the preponderance of non-additive gene action. Among the lines ACM 14-007 SI-2 and GT 10 and among the tester TMV 7 and TMV 5 exhibited high and significant per se performance for seed yield and its component traits. The gca effects of the lines indicated that the line GT 10 was positive and maximum significant for the yield attributing characters. The hybrids ACM 14-007 SI-2×TMV 5 and GT 10×TMV 7 recorded high per se performance with significant sca effects for seed yield per plant its component traits. Based on standard heterosis, the cross combinations GT 10×TMV 7, ACM 14-007 SI-2×TMV 5 and GT 10×TMV 5 possessed significant high standard heterosis for seed yield per plant and its associated traits. The hybrids GT 10× TMV 7, ACM 14-007 SI-2×TMV 5 and GT 10×TMV 5 were rated as the best since it possessed desirable performance based on per se, sca effects and standard heterosis for most of the yield attributing characters and so these hybrids could be exploited for further crop improvement. Abstract S. Ranjith Raja Ram