THE EFFECT OF THE STEM ROT AT COMPOSITION AND CONTENT OF PHENOLIC COMPOUNDS IN LEAVES OF BIRCH (BETULA PENDULA ROTH.)

Abstract

Stem rot cause significant ecological and economic damage to forests. Affected stands are prone to windbreaks and windfalls. Value of wood and stability of stands are reduced. Despite intensive studies of resistance biochemical aspects to rotting diseases, role of phenolic compounds remains insufficiently clarified. The purpose of research was studying composition of phenolic compounds in birch leaves with a significant level of damage to the diameter of the trunk. Stem rot was determined by taking core from trunk. Biochemical composition of leaves determined by HPLC. There are 64 phenolic compounds was revealed. 24 factions identified, 45.83% of compounds in affected trees, content was increased. Flavonoids are prevail (63.64%). In 45.83% of compounds, content decreased. They had predominance of flavonoids (81.82%). All compounds possess antioxidant activity. They contain phenolglycosides, determining entomoresistance (arbutin, salicin, salidroside). The results showed that with significant infestation with rot, there is an increase in the content of phenolic compounds in the leaves, therefore, the biochemical processes of combating oxidative stress are activated. This is due to violation of physiological and biochemical processes in diseased trees.