Choice of initial forms for selection of Prunus cerasus L. resistant to spring frosts

The presented article summarizes the results of studies of the resistance of sour cherry genotypes during 2018-2020 to spring frost. The studies were carried out on the basis of the laboratory of physiology of resistance of fruit plants of the Russian Research Institute of Fruit Crops Breeding. The research material is sour cherry genotypes of the Institute of breeding. The purpose of this research is to study the resistance of sour cherry genotypes of the RRIFCB breeding to spring frost by the method of artificial freezing and to isolate the initial forms of resistance for further breeding for a given trait. As a result of artificial freezing, a high resistance of flowers and buds to spring frost of -1.0°C was determined in the genotypes of Businka, Muza, Rovesnitsa, 84847 and 84854. After the action of a temperature of -2.0°C, a sufficiently high level of resistance of reproductive organs was established in the following sour cherry genotypes - Vereya, Kapelka, Muza, Novella, Podarock uchitelyam, Rovesnitsa, Turgenevka, Shokoladnitsa, 84735, 84847 and 84854. After the action of a temperature of -3.0°C, a highly resistant hybrid form 84847 was identified with the least number of dead flowers and buds - 12.0%. The resistant sour cherry genotypes were also noted (Businka, Shokoladnitsa, 84735 and 84854), in which flowers and buds were damaged in total not more than 50.0%. Based on the research results, the distribution of experimental sour cherry genotypes into groups of resistance to spring frosts was carried out. Using experimental data, a highly resistant sour cherry genotype 84847 was identified, which was recommended as the initial form of resistance of reproductive organs to spring frosts for further breeding for a given trait.