Abstract

                                Desirable significant negative heterosis over mid parent was observed for days to 50 percent flowering and maturity almost in all the cross combinations. involving the parent EC 69874. Significant and positive hetrerosis for plant height, head diameter, number of leaves, 100 seed weight and harvest index was also evident in most of the crosses. Heterosis was of low magnitude in case of head diameter and negative in direction for oil content. Heterosis over mid parent for seed yield per plant ranged from 17.4 to 102.7% and the cross Kanpur Selection X Co 1 recorded the highest value. The crosses EC 100101 x K 2, K 74xCo1, K74xK 1 and EC. 68415xCo 1 recorded significant positive heterosis for seed yield and most of the yield components. Significant and positive heterosis over mid parent for oil content was noticed in the hybrids of EC 93617 x Co 1 and EC 22237 x Co 1.

Key words : Sunflower, Heterosis