Chemeris O. Adaptive reactions of Pinus sylvestris L. seedlings and Pinus pallasiana D.Don seedlings infected with fungus Heterobasidion annosum (Fr.) Bref.

The thesis is devoted to study of changes in the functioning of the antioxidant system and in the maintenance of the complex of low molecular weight compounds in P. sylvestris and P. pallasiana seedlings during infection by phytopathogenic fungus H. annosum. The increase of the content of hydrogen peroxide and changes in the activity of antioxidant enzymes in the P. sylvestris and P. pallasiana seedlings infected with strains of H. annosum, which indicates the active response of the host plant. It was found that treatment of 2 mM solution of salicylic acid seeds of P. sylvestris and P. pallasiana during 1 and 3 hours increased their germination. Improving the resistance to the pathogen of the seedlings from the treated salicylic acid seed is associated with the ability to regulate the activity of antioxidant enzymes. It was established that the accumulation of low molecular weight compounds, free amino acids and carbohydrates in P. sylvestris and P. pallasiana seedlings due to infection of plants with different pathogenicity strains of the fungus H. annosum. The different nature of the changes in the content of low molecular weight compounds associated with differences in the metabolic processes of the infected plants, the power of influence of strains of H. annosum, causing defeat of pine seedlings.