The development of new high-yielding and stable sunflower hybrids based on interspecific hybridization requires information on the heterotic effects for agronomically important traits in the F, generation. Heterotic effects for seed yield, plant height and head diameter were studied in interspecific sunflower hybrids developed by the line x tester method. The female inbred lines were developed by interspecific hybridization, while the male restorer inbreds with good combining abilities were used as testers in the form of fertility restorers. F, hybrids were obtained by crossing each tester with each female inbred. The inbred lines and their F, hybrids differed significantly in their mean values of the traits under study. Heterosis values for seed yield per plant were positive and highly significant relative to both the parental mean (98.4-274.1%) and the better parent (54.8-223.2%). Significantly less heterosis was recorded in the case of plant height relative to parental mean (19.0-66.0%) and better parent (-3.9-51.6%). With head diameter, the heterotic effect ranged from 19.0 to 55.6% (parental mean) and from 7.8 to 36.6% (better parent). The results of this study may be used for the development of new high-yielding and stable sunflower hybrids based on interspecific hybridization.
Combining Ability and Type of Gene Action Analysis of Yield and Yield Components for Some White Maize Inbred Lines