Inheritance of seed size in sunflower

Abstract

There are several ways to increase yield per unit area. One of the most commonly used ways is to increase seed size and seed number per head while maintaining or raising the number of plants per unit area. Breeding for seed size may prove to be of great importance in increasing sunflower yields. In order to study the mode of inheritance, components of genetic variance and combining ability for seed length, width and thickness (seed size), half diallel crosses of six divergent sunflowers inbred lines were made. The results have shown that there existed significant differences between the parent lines and their progenies regarding the mean values of the three traits. In the inheritance of seed length, width and thickness, the additive gene effect proved to be of great importance since the value of the additive component (D) was considerably higher than that of the dominant component (H1, H2). The average degree of dominance indicates the presence of partial dominance in the inheritance of the three investigated traits in the progenies. The inbred line cms-13 had the highest positive values of general combining ability for all examined characters. The best specific combinations for all three investigated traits were R-15 x cms-19 and cms-77 x R-18.