The content of polyphenols in low-growing apple rootstocks depending on the type of soil in Central Russia

Abstract

Field studies were carried out in 2017-2021. in horticultural farms of Central Russia. We analyzed 11 varieties of apple trees in four seasons (winter, spring, summer, autumn) for the content of polyphenols in the rootstocks of apple trees - dwarf 62-396, semi-dwarf 54-118 and dwarf PB-9, grown on 7 types of soil: floodplain granular, floodplain layered , podzolized chernozem, leached chernozem, meadow-chernozem, gray forest and sod-podzolic soil. It was found that of all the organs of cultivated varieties of apple trees, the largest amount of polyphenols is concentrated in 1-2-year-old shoots. The highest concentration of flavonols in the shoots of all studied rootstocks and catechins in the shoots of rootstock 54-118 was when growing on the most low-fertile soddy-podzolic soil. It was found that the content of flavonols in apple shoots is less affected by the weather conditions of the year than the content of catechins. The content of catechins in the annual shoots of the apple tree is an unstable variable indicator. Its value may increase or decrease by 5.4-12.0 times during the first two years. Of the three apple tree rootstocks, the largest amount of flavonols was noted in shoots 62-396, and catechins - in shoots 54-118. It was found that with an increase in the proportion of fine dust and physical sand and a decrease in the proportion of medium dust in the soil, the content of flavonols in the shoots of the dwarf apple rootstock 62-396 increases, the less medium dust in the soil, the more flavonols are contained in the shoots of the semi-dwarf apple rootstock 54-118. With an increase in the content of medium dust in the soil, the content of catechins increases in the shoots of the dwarf rootstock of the PB-9 apple tree. It was proposed that the accumulation of flavonols in the annual shoots of apple rootstocks should be considered as an adaptation to a decrease in soil fertility.