MODIFICATION OF PEROXIDASE AND CATALASE ACTIVITY IN APPLE TREE LEAVES DEPENDING ON GROWING CONDITIONS AND BIOLOGICAL PARTICULARITIES OF VARIETIES

Valentina SVETLICENCO,Ana POPOVICI,Alexandru NICUȚĂ,Universitatea de Stat din Moldova

Abstract

The aim of this study is to evaluate the dynamics of the activity of the enzymes peroxidase and catalase in the leaves of the winter apple varieties Golden Spur and Granny Smith during the growing season. The importance of these enzymes lies in their participation, with a differentiated role, in the adaptation and resistance of the trees to unfavorable environmental conditions, as well as in the processes of growth, development and fruiting. The values ​​of the enzyme activity investigated during the vegetation period changed depending on the physiological-biochemical processes that took place in certain phenophases of tree development, the growth conditions (temperature, soil mois- ture, atmospheric drought, etc.), as well as the biological particularities of the varieties. In the case of both varieties, the activity of peroxidase and catalase in the leaves was more increased in the variant with plants grown under non- irrigated conditions. Keywords: apple trees, varieties, leaves, peroxidase, catalase, humidity, water stress DOI: https://doi.org/10.59295/sum1(191)2026_34