Kryshtop Y. Wide hybridization of spring cereals and their modification by low temperature

Object: effects of low temperature influence at wide hybridization of spring cereals. Aim: to determine the features of crossability of different species and varieties of spring wheat with spring rye depending on the duration effect by low temperature on seeds of maternal plant; to clarify a question of mechanism of low temperature effect on seeds of maternal plant; to establish the viability and productivity of intergeneric hybrids of the first generation depending on the action of low temperature; to find out the nature of splitting and type-forming process intergeneric hybrids of the second generation and their productivity depending on the action of low temperature. Methods: field, laboratory, cytological, electrophoresis, statistic. Novelty: for the first time some side of mechanism of low temperature action on seeds of mater-nal plant are clarified: action of low temperature changes mitotic activity of root meristem cells in the germinating seeds of spring wheat, provokes chromosomal abnormalities in it and changes in the spectrum of reserve proteins of seeds and sprouts that promotes to increase of crossability between kinds and depends not only on specie, variety and cross combination, but on tempera-ture and duration of its influence. Results: presowing treatment of seeds of maternal plants by low temperature -14 оС with exposure of treatment for 168 hours increases crossability of different species of spring wheat with spring rye, viability and productivity of intergeneric hybrids of first generation and changes nature of form-building process of intergeneric hybrids of second generation. The application stage: the best varieties are assigned, which can be used as parent forms for crossing with task of selection for ear productivity increasing and increasing of phenotypic va-riability level of hybrid posterity; the most valueable lines, which are characterized by high productivity and quality of grain, and are used in breeding program of Chair of Genetic, Breed-ing and Seed-Growing at Kharkiv National Agrarian University named by V.V.Dokuchaev. The application sphere: selection institutions.