Combining Ability Studies on Sunflower (Helianthus Annuus L.)

Five CMS lines were crossed with 12 testers (6 branching and 6 non-branching restorers) in L x T mating design to estimate the combining ability in sunflower (Helianthus annuus L.). In majority of the crosses, high Specific Combining Ability (SCA) effects were due to high x high or low x high general combining ability of the parents. The best crosses for seed yield (4545A#NDOL-3XVI-46(Br)) and for seed oil content (4546A#NDOL-3XRHA-265(NB)) with high SCA effect were identified. The estimates of SCA variance were higher than general combining ability (GCA) variance for all the characters, which indicated predominance of non-additive gene action. Considering the seed yield potential of hybrids the possibility of utilizing non-branching restorer lines in heterosis breeding programme was pointed out, despite shorter period of pollen supply in hybrid seed production plots.