Hybridological analysis of inheritance of length and width of leaves in hybrid combinations Burley tobacco

The way of inheritance, the coefficient of heritability, the manifestations of heterosis, transgression and depression in terms of the length and width of the leaves in hybrid combinations Burley tobaco are established. For that purpose are studied, the Р1 , Р2 , F1 and F2 populations of eight crosses Burley tobacco. The obtained results suggest that inheritance of the length or leaves is overrdominantly, incompletely dominantly or additive, and of the width of leaves is incompletely dominantly and overrdominantly,, as in both indicators it is always in the direction of the parent with higher values. Manifestations of heterosis and transgression are of economic importance only in terms of leaf width. The minimal number of genes that control the expression of the studied indices is small and uniform and the length and width of the leaves. The phenotypic expression of leaf size is strongly influenced by negative epistatic interactions, especially pronounced at their width. The established medium to higher values of the coefficient of heritability of the length of the leaves are an indication of a relatively equal share of influence of genotype and environmental conditions on the phenotypic manifestation of leaf length, which suggests that the selection on this indicator to be effective in earlier hybrid generations. The selection of width of the leaves will be effective in later hybrid generations due to lower values coefficient of the heritability, for this indicator. This shows that the coefficient of heritability and the related coefficient of efficiency of the selection is different in both indicators, making it difficult selection work.