Makarchuk M. Improvement of crossbreeding methods for raising the efficiency of hybrid maize seed production.

The thesis is devoted to clarifying the effectiveness of applying genetic markers in different genetic system of controlled propagation (GSCP) as to the demonstration of economically valuable features of maize hybrids, compared to traditional methods of hybrid seed production under different agro-ecological zones. As a result of the research, it was established that during cultivation of coisogenic analogues in agro-climatic conditions of Forest-Steppe and Steppe zones, the presence of genetic markers a1, a2 and ACR in the genotype of the maternal components, and a1, CI, and P-RR in the paternal components did not lead to lowering yields and to reducing general economically valuable features of the hybrids. It was also determined that the use of the genetic system of controlled propagation based on the gene Vg of a functional type and genes ms5 and ms13 of a nuclear type of sterility under the presence of a genetic marker a2 does not reduce the productivity of maize hybrids. The adaptive capacity of coisogenic analogues of hybrids depending on the genotype of the parent component was established. The reaction of the hybrids to fluctuations of hydrothermal conditions of growing is determined according to the regression coefficient. The evaluation of coisogenic analogues of maize hybrids according to main agronomic features is carried out. It is established that the increase in plant height and height of attachment of commercially valuable cob of a simple hybrid under the agro-climatic conditions of Forest-Steppe and Steppe zones, as well as a substantial reduction in the trilineage hybrid under the conditions of a Steppe zone did not affect their suitability to mechanized harvesting. The technology for micropropagation of the components of maize hybrids is improved. According to which it is determined that the best conditions for the sterilization of explants is 10% sodium hypochlorite and 3% sodium percarbonate with a 15 minute exposure. As a result of the evaluation of economic efficiency it was established that introducing markers a1, a2, ACR, CI and P-RR into a hybrid combination of genetic markers does not reduce yield, and, accordingly, does not reduce the profitability of their cultivation.