Combining Ability in Sunflower

Abstract

Combining ability studies in sunflower were undertaken in seven environments with a set of 12 x 12 diallel excluding reciprocals for the characters days to flowering, days to maturity, plant height, stem diameter, number of leaves, head diameter, per cent unfilled seeds, 100-seed weight, seed yield per plant and oil content. The variances due to general and specific combining ability were highly significant for all the characters under all the environments with a higher magnitude of the former. However, the ratio s2s/s2g depicted the preponderance of non-additive type of gene action for all the characters except days to flowering and days to maturity. Based on the general combining ability effects under different environments, parents EG 69874, EG 60877, EG 77195, EG 27628 and EG 68413 have been proposed for using either in the development of a synthetic variety or for constituting a base population for the improvement of seed yield and its influencing characters such as plant height, stem diameter, number of leaves, head diameter and 100-seed weight along with the simultaneous improvement of oil content. Some of the crosses, with high sea effects and involving both the better general combining parents, such as EG 36371 X EG 81837-1 for days to flowering, EG 81836 x EC 69874 for days to maturity, EC 60877 x EG 77195 for plant height and EG 60877 X EG 15527 for oil content have also been identified for isolating better recombinants for respective characters.