Heterosis in relation to combining ability in restorer lines of sunflower

Abstract

In order to execute a breeding procedure efficiently, it becomes inevitable to examine the relationship between combining ability and heterosis. In the present investigation, diallel analysis of restorer lines (R lines) and their restorer × restorer (R × R) crosses was employed to identify and develop elite 'R' lines for subsequent use in sunflower hybrid development programs. Crosses with high SCA effects were arranged in order of their per se performance, general combining ability of the parents of these crosses and per cent heterosis over standard check hybrid LSFH-35 and KBSH-1. Best GCA effects and high mean performance characters were observed between high × high, low × high or low × low general combiners. The combinations J/6 × NDR-1, 6D-1R × DMLT-1Y, NDR-1 × LR-451 and 6D-1R × DMLT-1Y, which were best for seed yield/plant, oil content and 100-seed weight and head diameter, respectively, were between high × high combining parents, indicating additive × additive effects are fixable components, and single plant selection would be desirable in their segregating generations. The combination NDR856 × 6D-IR, with high per se performance for pollen productivity, was between low × high combining parents, and the combination 6D-1R× NDR-1, for plant height, was between low × low combining parents, indicating better complementation between favorable alleles of the involved parents.