Five lines were crossed with 10 testers in L x T mating design to estimate the combining ability for seed yield in sunflower. Non-additive genetic variance played a predominant role in the inheritance of all the characters studied viz., days to 50 per cent flowering, days to maturity, plant height, head diameter, number of seeds per head, 100 seed weight, seed yield per plant, hull content, volume weight and oil content. The lines CMS-148 and CMS-607 and testers SVR-467, SVR-490 and SVR-491 can be considered as superior parents in the present study as they recorded high per se performance with positively significant general combining ability effect for seed yield per plant. Good general combiners for seed yield were also the good general combiners for one or more yield contributing traits. Among the 50 hybrids evaluated, crosses viz., CMS-107 x SVR-472, CMS-378 x SVR-444 and CMS-351 x SVR-495 were considered as superior hybrids as they recorded high per se performance and significant specific combining ability effect for seed yield per plant.

Five cytoplasmic male sterile lines and 10 testers were crossed in an L x T mating design to develop 50 sunflower hybrids. The hybrids and parents were evaluated during Kharif-2013. Highly significant differences existed among genotypes for all the traits studied. The highest magnitude of positive relative heterosis and heterobeltiosis for seed yield per plant was exhibited by the cross CMS-148 x SVR-467 followed by the crosses CMS-351 x SVR-467, CMS-107 x SVR-472 and CMS-107 x SVR-467. The hybrid CMS-148 x SVR-467 (21.19%) exhibited positive and significant heterosis for seed yield per plant over check Phule Raviraj. The heterosis for seed yield in hybrids was found to be mainly influenced by plant height, head diameter, number of seeds per head and 100 seed weight. The highest positive relative heterosis and heterobeltiosis for plant height was exhibited by the cross CMS-378 x SVR-490, whereas, for head diameter it was exhibited by the cross CMS-607 x CMS-467. The heterotic effect for number of seeds per head was more pronounced in cross CMS-607 x SVR-467 over both mid and better parents. The hybrid CMS-607 x SVR-496 recorded higher magnitude of heterosis for number of seeds per head over check Phule Raviraj. Highest significant and positive heterosis for 100 seed weight and protein content was exhibited by the hybrid CMS-607 x SVR-490 over mid parent, better parent and standard check Phule Raviraj.