PHYSIOLOGICAL AND BIOCHEMICAL ASPECTS OF GROWTH AND MATURATION OF APRICOT (PRUNUS ARMENIACEAE) VARIETIES OF MOSCOW SELECTION IN CENTRAL RUSSIA

Background. Apricot is one of the most popular fruit crops in the world. Central Russia belongs to the moderately cold climatic subzone of climatic zone II with the sum of effective temperatures of 1000-2200ºС. Therefore, the biological characteristics of apricot varieties for this zone must correspond to the environmental conditions of the region. Studying the process of fruit ripening of winter-hardy apricot varieties can be useful when carrying out breeding work. Purpose. To study the dynamics of the main physiological and biochemical parameters of leaves and fruits of apricot varieties of Moscow selection. Material and methods. The object of the study was the fruits and leaves of apricot varieties selected by GBS RAS (Moscow) during the formation and ripening of fruits. During the period of fruit formation (June-August), the content of mono- and polysaccharides, photosynthetic pigments - chlorophylls and carotenoids, flavonoids, as well as the HPLC method of some phenolcarboxylic acids was determined in the samples using the spectrophotometric method according to generally accepted methods. Morphometric indicators were also recorded: weight and diameter of the fruit, leaf area. Results. Varietal specificity has been established based on the studied biochemical and morphometric parameters of leaves and fruits. The largest fruits were in the Tsarsky variety, the minimum size in the selected Zachatievsky variety. A similar picture was observed for fruit diameter and leaf area. The level of chlorophylls and carotenoids in the leaves remained stable throughout the entire study period in the Tsarsky variety, the best in terms of fruit ripening and taste. In the leaves of the Tsarsky variety in June and July, the level of carotenoids was ~35% higher than in other samples. No significant varietal differences were found in the content and ratio of mono- and polysaccharides. A decrease in the level of phenols and an increase in the content of polysaccharides and carotenoids contributed to the formation of the sweet-sour taste and color of the fruit. The presence of phenols involved in the activation of protective mechanisms at all stages of fruit formation and development apparently makes it possible to overcome the negative effects of weather conditions. According to biochemical and organoleptic indicators, early ripening varieties Tsarsky and Lel are distinguished. Conclusion. The dynamics of the biochemical composition of leaves and fruits of winter-hardy apricot varieties of Moscow selection during the process of fruit formation was studied for the first time. Such data may help identify markers for selecting breeding material with adaptive capabilities to biotic and abiotic stresses in central Russia.