Inheritance of dwarfism trait by winter wheat mutants induced in the Chornobyl NPP exclusion zone

Abstract

Background. The development of short-stem cultivars is an effective way to increase the productivity of winter wheat grown under the intensive cultivation techno­logy. Dwarf mutants, induced in the exclusion zone of ChNPP, can preserve a productive potential of an initial cultivar and be of a breeding value. The knowledge of the inheri­tance regularities of stem length by dwarf winter wheat mutants makes it possible to choose the pairs for crossing better and predict a final result in hybrid generations earlier. Materials and methods. Hybrids F1 і F2 of Triticum aestivum L. were received by crossing medium-grown cultivar Sonechko with dwarf mutant lines UK 1145/10, UK 1147/10, and UK 1148/10, induced by the effect of the radionuclide contamination of the exclusion zone of ChNNP on the plants of ‘Albatros odeskyi’ cultivar. The nature of the trait inheritance in F1 was determined by the degree of phenotype dominance, the variability of plant height was determined by a variation coefficient. The segregation frequency of dwarf, low-, medium- and high-grown forms was accounted in the population of F2 plants. Results. By stem length, plants F1 exceeded the genotypes involved in hybridization, or were closer to parental forms with a greater manifestation of the trait. The real heterosis in the plant height decrease was shown in the F1 hybrid ‘Sonechko’ × UK 1147/10. The hybrid productivity elements are inherited by the type of a partial positive dominance and over-dominance. From 2.2 % to 3.6 % of high-grown forms, atypical for parents, were recorded in the population of F2. Conclusions. When the crossing combination includes a medium-grown cultivar of winter wheat and dwarf mutants, induced in the exclusion zone of ChNPP, a stem length in F1 is inherited by an intermediate type and partial positive dominance. Dwarf mutant UK 1147/10 can be valuable for breeding short stem winter bread wheat. A significant variation of such indicator as a degree of phenotype dominance by all studied features confirms a complicated nature of genetic determination of a plant height and the productivity elements of winter wheat, in the formation of which various types of gene interaction take part.