STUDY OF HEAT AND DROUGHT RESISTANCE OF PRUNUS CERASUS L.

Abstract

The studies were carried out on the basis of the Laboratory of physiology of resistance of fruit plants of Russiаn Reseаrch Institute of Fruit Crоp Breeding in 2018–2020. The objects of research were cherry varieties of the Institute's breeding: Bystrinka, Novella, Konkurentka, Muza, Orlitsa, Podarok uchitelyam, Rovesnitsa and Shokoladnitsa. The check variety was Turgenevka variety. Clone rootstock was B-2–230. To determine the drought resistance of cherry varieties, the method of withering was used. The heat resistance of cherry varieties was studied by heat shock (exposure to a high temperature of +50 °C). The goal of the research was to study the heat and drought resistance of cherry varieties based on the determination of water regime parameters in the laboratory conditions. The following parameters of the water regime were determined: hydration, fractional composition of water, water deficit, recovery of leaf water content. A strong relationship was established between the water content of cherry leaves and the average daily temperature (r = 0.83). In the field, there was a decrease in water content of leaves of cherry varieties by 5.9 % in July and in August by 8.4 % compared to June. During the period of mass fruit maturation (July), there was a decrease in the amount of free water in the cherry leaves by 4.2 % and an increase of bound water by 0.7 % compared to June. It was shown an increase of water deficit of leaves in a greater level during the fruit ripening period (July) and during the onset of dry and hot conditions. After dehydration and exposure to heat shock, an increase of water deficit in leaves was noticed by 16.0–24.2 % and 31.1–39.0 %, respectively. During the years of research, the studied cherry varieties were characterized by a high ability to recovery of leaf water content after dehydration from 114.8 to 177.7 % and heat shock from 91.8 to 125.3 %. It was found that the studied cherry varieties were shown the similar physiological parameters of the water regime and an average level of resistance to drought and high temperature. In this regard, they were assigned to the group of medium heat and drought resistance at the level of the check variety.