Strawberry collection assessment by white leaf spot resistance in the Middle Urals conditions

White leaf spot is one of the most common diseases of garden strawberries. Affecting the leaves, the disease leads to disruption of the physiological processes in the plant, causing inhibition of the growth and development of the plant itself, affecting the quality of the berries and reducing the yield by 15–40 %. There are currently no varieties of strawberries immune to the disease. In the industrial cultivation of strawberries, chemical means of protection are traditionally used, which pollute the biosphere. And obtaining environmentally friendly berry products, without the use of pesticides, is associated with an increase in its cost. The breeding of strawberry varieties resistant to white spot is further complicated by the fact that the resistance of varieties varies depending on the races of the causative agent of the disease and on the age of the plant. But at the same time, the complex genome of garden strawberry makes it possible to select resistant hybrid seedlings in the offspring when using more resistant to disease initial forms in breeding. The purpose of research is to isolate from the collection of strawberries varieties resistant to white spot in the Middle Urals with further use in the breeding process. The studies were carried out in 2010–2020 in the structural subdivision of the Ural Federal Agrarian Research Center of the Ural Branch of the Russian Academy of Sciences - Sverdlovsk Horticultural Breeding Station in accordance with the "Program and Methodology for Variety Study of Fruit, Berry and Walnut Crops". The study included 32 varieties of strawberries of domestic and foreign selection, including 6 varieties of Station selection (Akvarel, Geyser, Darenka, Duet, Orlets, Torpeda). According to the research results, the varieties Sara and Karmen were identified with the least damage to the leaves by the disease (the maximum degree of damage is 1.0 points). The rest of the varieties in the collection were more susceptible to the disease - the degree of damage was 2.0–4.0 points. Cultivars Sara and Karmen are planned to be used in breeding for white spot resistance as parental parent forms.