The effect of Pinus sylvestris L. plantings on the components activity of legumes antioxidant system

The paper shows the content of some components of the antioxidant system (ascorbic acid and peroxidase) in the leaves of leguminous plants growing under Pinus sylvestris L. plantings during the growing season. The studies were conducted on the territory of the Kuzbass Botanical Garden (coordinates 55,366186, 86,190160). The objects of the research were Melilotus officinalis and Trifolium repens. The ascorbic acid content was determined by the titrimetric method, peroxidase activity was determined by spectrophotometry. The components activity of the antioxidant system in the leaves of leguminous plants growing under P. sylvestris plantings depended on the species characteristics and the period of plant vegetation. The activity of peroxidase during the growing season in the leaves of Trifolium repens is higher than in the leaves of the Melilotus officinalis. As plants grow and develop, peroxidase levels increase. The content of ascorbic acid in the leaves of leguminous plants revealed an inverse relationship. The studied samples were characterized by the least variability in the content of ascorbic acid, in comparison with the activity of peroxidase. In the Melilotus officinalis, the gap in the variability of ascorbic acid decreased by 1,4 times, compared with Trifolium repens. The closest negative relationship in legumes was found between the activity of peroxidase and organic matter, mobile phosphorus; a positive correlation was noted between peroxidase and the amount of absorbed bases, which indicates a possibility of using the obtained data as diagnostic signs of plant conditions for monitoring natural ecosystems.