Genetic determination of elements of the soybean yield structure and combining ability of hybridization components

The value of soybean varieties in terms of general combining ability (GCA), constants of specific combining ability (SCA) and their variances in terms of productivity elements in two-tester top-cross crossings were determined. Differentiating ability of Hoverla and KyVin testers was revealed. The degree and frequency of positive transgressions in hybrid populations were established.There were established high effects of general combining ability by plant height and height of attachment of lower beans in Sawyer 2-95 variety and KyVin tester; by the number of productive units in Sawyer 2-95 variety and Hoverla tester; by pod number per plant in Sawyer 2-95 and Kyivska 97 and Hoverla tester; by seed number per plant in Kyivska 97 and Medea varieties and Hoverla tester; by 1,000 seed weight in Sawyer 2-95 and Kyivska 97 varieties and Hoverla tester; by seed weight per plant in Medea and Kyivska 97 varieties and Hoverla tester; in terms of yield in Medea variety and Hoverla tester. It was found that additive effects of genes were dominating in genetic control of the traits of plant height, height of attachment of lower beans, number of productive nodes, pod number per plant, seed number per plant, 1,000 seed weight, seed productivity and yield, the share of non-additive effects of the gene interaction was lower, however, it was also reliable. Analysis of dominance indicators revealed combinations of crosses that were distinguished by overdominance of these traits and had significant breeding value: Sawyer 2-95 × Hoverla, Kyivska 97 × Hoverla, Medea × Hoverla.