Study of the Degree of Resistance of Stone Fruit Ovary to Late Spring Frosts and Its Mechanisms

Late spring frosts often cause complete yield losses in stone fruit crops, reducing the profitability of orchards in the Lower Volga and Central Russia. The aim of this research is to identify sources of high resistance of stone fruit genotypes to late spring frosts at the ovary stage for use in breeding, as well as to identify possible mechanisms of resistance of reproductive organs to low temperatures. In the field, after two recurrent spring frosts with temperatures of -2°C and -4°C, ovary resistance was studied in 10 cherry, 17 sweet cherry, 10 plum, 10 plum-sloe hybrids, 43 apricot, and 27 peach varieties. Genotypes with the highest resistance to late spring frosts were identified. Hormonal and water balance characteristics of developing ovaries were studied in peach genotypes with contrasting frost resistance and apricot varieties with contrasting winter hardiness. The main criteria for selecting genotypes with resistance to recurrent spring frosts and areas of research into potential resistance mechanisms are outlined.