PHYTOPATHOGENIC MYCOBIOTA IN AGROCENOSES OF CULTURAL PLANTS IN THE CONDITIONS OF THE CENTRAL FOREST STEPPE OF UKRAINE

Abstract

Intensive development of phytopathogenic micromycetes in the agrocenoses of cultivated plants leads to significant crop losses, deterioration of its quality and reduction of plant productivity. Phytopathogens are a powerful factor in biological pollution of agroecosystems. The purpose of our study is to determine the number and species composition of micromycetes on the leaves of sunflower plants of Dushko and Oliver hybrids and winter wheat of Podolyanka and Skagen varieties in the agrocenoses of the Central Forest Steppe of Ukraine. Studies of the mycobiome of the leaves of sunflower plants have shown that the number of micromycetes is significantly influenced by the biological features of the investigated sunflower hybrids and their cultivation technologies. It was established that the number of phytopathogenic micromycetes on the vegetative organs of the investigated hybrids under the organic technology of sunflower cultivation was at the level of the traditional technology and varied between 14.6 and 19.9 thousand CFU/g of dry leaf. The species composition of micromycetes on the leaves of sunflower plants was determined and it was established that the dominant fungi are the following genera: Aspergillus P. Micheli ex Haller, Alternaria Nees, Penicillium Link; Fr, Fusarium Link and Cladosporium Link. They were characterized by a different frequency of occurrence during the growing season, which ranged from 15 to 70%. According to the results of the research of the mycobiome of the leaves of winter wheat plants, it was established that the number of micromycetes on plant leaves ranged from 0.9 to 3.8 thousand CFU/g of dry leaf and significantly depended on the cultivation technology and biological characteristics of plants of different breeding origins. Metabolites of Podolyanka winter wheat plants under conditions of both traditional and organic growing technology stimulated the development of micromycetes in the mycobiome of vegetative organs of plants. Metabolites of Skagen winter wheat plants under conditions of different cultivation technologies restrained the development of micromycetes at an ecologically safe level. The species composition of micromycetes on the vegetative organs of winter wheat plants was determined, and it was established that under the conditions of traditional growing technology, the dominant micromycetes were the species F. oxysporum, F. graminearum, and B. sorokiniana with a frequency of occurrence of 55 to 70%. And in the conditions of organic cultivation technology - F. oxysporum and T.viride, the frequency of which was 50%. Micromycetes of these genera are toxin-producing species that contaminate agricultural crops with mycotoxins, which poses a danger to animal and human health.