Home – Home – Jornals – Contemporary Problems of Ecology 2023 number 4

The interaction in the system “epiphytic microorganisms - host plant-pathogen” was considered on the example of Scotch pine (Pinus sylvestris L.) seedlings which artificially infected with the facultative saprotroph Lophodermium seditiosum Minter, Staley & Millar. At the same time, the change of quantity of the epiphytic microorganisms, the composition and concentration of volatile compounds and the morphological parameters of pine in different variants of the experiment were studied. The influence of two factors on the studied characteristics was considered: L. seditiosum infection and the introduction of mycocompost into the soil. Classical phytopathological and microbiological methods were used. Volatile compounds were studied using chromato-mass spectrometry, phytoncide activity was studied using the Tokin method adapted to our conditions. At the stage of ascospore germination, an increase in the amount of volatile components released by the affected needles and a decrease in the number of those released by the roots of infected plants were noted. Against the background of changes in the composition of volatile compounds, an increase in the phytoncide activity of the leaf and root systems of plants with signs of the disease was found compared to specimens without signs of damage. This is also evidenced by the results of microbiological cultures: in the variants with infection, compared with the control, a significant decrease in the number of epiphytic microorganisms was noted. A significant increase in the mass of needles was noted in the variants with infection and with the adding of mycocompost, confirmed by ANOVA analysis. Registered correspond to Selye’s adaptive syndrome (activation of physiological processes at an early stage of adverse effects, followed by exhaustion of the body if the load continues).