Study of gene action for restorer lines in sunflower

Abstract

Five best sunflower restorer (BR) lines and five elite restorer (ER) lines which were crossed in all possible combinations with half diallel fashion to determine the combining ability, mode of gene action and to quantify the magnitude of heterosis at Oilseeds Research Unit, Dr. PDKV, Akola Maharashtra (India). The ratio of σ2GCA/σ2SCA variances was less than unity for plant height, head diameter, filled seeds/head, 100 seed weight, harvest index, oil content and yield/plant indicating non-additive type of gene actions were involved in these traits. The character, days to maturity was governed by preponderance of additive gene action due to variance ratio observed more than unity. The characters days to maturity, head diameter and 100 seed weight showed the predictability ratio nearer to unity indicating greater predictability based on general combining ability alone. Six crosses 270R × Ak-1R, 272R × 273R, 273R × 274R, 586R × 857R, 265R × Ak-1R and 265R × 586R appeared to be worth exploiting. These promising R × R crosses can be used for the development of new R lines in sunflower. It is recommended that in order to get new restorer combinations it is necessary to have at least one elite restorer in combination with best restorer to be incorporated in the breeding programme and vice-versa at least in sunflower.