Degree of phenotypic dominance and heritability of the plant height in wheat hybrids with different alleles of Rht genes

The degree of dominance and the heritability coefficient have been investigated as the markers of allelic interactions of the loci Rht8 and Rht-B1. The interaction is characterized by partial or total dominance or even by overdominance of greater plant height and by low or medium heritability. The alleles that exert a weaker direct negative effect or no such effect predominate over the alleles that predispose to a more pronounced reduction of plant height. The impact of weather conditions on the switch of dominance is discussed. The Kooperatorka line has an additional allele (or alleles) that predisposes to greater plant height; the mode of inheritance of these alleles is partially recessive. An unidentified semidominant gene (or genes) that determines small plant height is present in the genotype of the Odes’ka 3 line. The presence of heterosis related to heterozygosity for certain genes not critically relevant for the present study makes the assessment of the allelic interaction characteristics under investigation more complicated.