Syvoded Y. Features of the Pathogenesis of Sunflower Phomopsis and Biology-Ecological Aspects of the Pathogen Diaporthe (Phomopsis) helianthi Munt. – Cvet. et al.

The thesis is devoted to the study of the sunflower phomopsis pathogenesis at the molecular, cellular and tissue levels in vivo and in vitro. The influence of abiotic factors on the disease development and spread of its pathogen in the southern region of Ukraine has been studied. Morphological changes in the structure of the pathogen reproductive organs caused by climatic factors were recorded. The cytotoxic and mutagenic actions of phenolic compounds Diaporthe (Phomopsis) helianthi М. with toxicity to cell division process have been experimentally confirmed. The features of the effect of secondary synthesis products on nuclear apparatus of plant cells and the processes of their separation have been investigated. It has been established that pathological process in infected plants depends on the concentration of toxic pathogen substances. It was determined that phenolic compounds of the secondary metabolites of fomopsis at low concentrations are able to identify antioxidant activity and intensify cell division processes. An increase in the concentrations of Diaporthe (Phomopsis) helianthi M. exometabolites of the fungus leads to impaired DNA distribution, total or partial dispersion of chromatin and impaired mitotic cycle of Allium cepa L. test plants. It is determined that development of these processes are affected by secondary metabolites: fomozine, fomopsolidides and cytosporons. Investigated the effectiveness of the inhibitory effect of fungicides on the growth of the fungus in vitro. Based on the study of changes in physiological and biochemical parameters in the process of Helianthus annuus L. lesions by the pathogen, an improved method for the rapid diagnosis of latent forms of the disease based on changes in the induction of chlorophyll fluorescence.