Assessment of components of genetic variance of mass 1000 seeds in sunflower -Heuanthus annuus L.-

Ten F1 hybrids obtained by crossing five sunflower inbred lines were used to analyze the impact of genes with additive and dominant effects and their interactions on the inheritance of mass 1000 seeds. The linkage among the expected progeny means was tested using the scaling tests method (Mather, 1949), while the estimates of gene effects and mode of inheritance were made by generation mean analysis (Mather and Jinks, 1982). The additive-dominant model was not proved adequate for all crosses in both years of study. It was adequate in crosses C1, C2, C3 and C5 in the first year and in crosses C3, C8, C9 and C10 in the second year of study. Besides the main gene effects (additive and dominant), epistatic gene effects were also of large importance in the inheritance of this trait. Duplicate epistasis between dominant decreasers was found in C1, C4, C5, C6 and C8 in the first year and in crosses C4, C9 and C10 in the second year of study. Complementary epistasis between dominant decreasers was found in cross C10 in the first year and duplicate epistasis between dominant increasers in cross C5 in the second year of study