Юг России: экология, развитие (Jul 2021)
Resistance of generative organs of sweet cherry to spring frosts after artificial freezing
Abstract
Aim. The purpose of this research was to study the sustainability of Institute bred sweet cherry cultivars to spring frosts during flowering by the method of artificial freezing and to identify resistant cultivars.Material and Methods. Seven Institute bred sweet cherry cultivars were studied: 'Adelina', "Malysh", "Orlovskaya Rozovaya", "Orlovskaya Feya", "Podarok Orlu", "Siyana" and "Trosnyanskaya". Spring frosts were simulated in an "Espec" PSL-2KPH climate chamber in early May at -1°, -2°, -3° and -4°C. At each temperature regime, 100 pcs of flowers and buds of each cultivar were taken in 3-fold repetition. Temperature was lowered at the rate of 1°C per hour. The duration of exposure to negative temperatures was 3 hours.Results. Damage to the stamens and pistils was assessed by the darkening of the tissues. In buds and blooming flowers after frosts, the pistils were first damaged but the stamens were not. Resistance to spring frosts decreased with the phenological development of the cherry's generative organs. The beginning of damage to the flowers as a result of the artificial freezing was noted at a temperature of -1°C. At the same time, the high stability of cherry buds was noted. Modeling frosts of -2°...-4°C increased the number of dead flowers and buds. The resistance of sweet cherries to spring frosts was found to depend on the genotype and stage of development of reproductive organs. A different sum of active temperatures for the beginning of flowering and ovary formation was noted, indicating the onset of phenological phases in which generative organs are susceptible to spring frosts.Conclusion. The experiment made it possible to distinguish a medium-resistant cultivar "Malysh" which was resistant to spring frosts. Weakly stable genotypes were "Orlovskaya Rozovaya", "Orlovskaya Feya", "Trosnyanskaya" and "Siyana". Unstable cultivars were "Adelina", and "Podarok Orlu". During the formation of the ovary, the greatest potential for resistance to spring frosts was shown by "Podarok Orlu".
Keywords