SUMMARY. The degree of dominance and the coefficient of heritability have been investigated as indicators of the allelic interaction at loci Rht8 and Rht-B1, which is characterized by the partial, complete or over dominance of greater plant height and by the low or medium heritability. Alleles with a weaker or without direct negative effect dominate under alleles reducing the plant height stronger. The impact of weather conditions on a change of the dominance is discussed. The line Kooperatorka has an additional allele (alleles), causing the greater heights of plants, with partially recessive mode of inheritance. An unidentified half-dominant dwarfing gene (genes) is present in a genotype of the line Odeska 3. The presence of a heterosis, caused by heterozygosity for genes, which are not critical in our research, distorts the evaluation of the allelic relationship characteristics studied.
Keywords: bread wheat, dwarfing genes, plant height, the degree of dominance, heritability coefficient
