Heritability of Indirect Bread-making Quality Traits in Segregating Generations of Two Winter Wheat Crosses

Modern wheat breeding programs aim to create cultivars with high genetic potential for yield and bread-making quality. The effectiveness of selection in segregating generations depends on the heritability of the traits under selection and on the correlations among traits. The aim of this study was to compare realized heritability of 1000 kernel weight and five indirect bread-making quality traits (grain protein content, wet gluten content, gluten index, the Zeleny sedimentation value and Pelshenke value) between segregating generations (F4 to F6) of two bi-parental wheat crosses, calculated using four different methods, and to estimate phenotypic correlations among these traits. Realized heritability of investigated traits, estimated as parent-off spring regression, ranged from 0.21 to 0.79. Realized heritability for wet gluten content, gluten index and Pelshenke value was much higher in comparison with other quality traits. Correlations between the four methods used to calculate realized heritability revealed the best agreement between heritability estimated as parent-off spring regression and that based on divergent screening, and the lowest agreement between realized heritabilities based on upward and downward screening. Strong positive correlations were observed among grain protein content, wet gluten content, and Zeleny sedimentation value; and strong negative correlations between gluten index on one side and grain protein content and wet gluten content on the other side.