The article considers the species composition of Dothideomycetes and its structural characteristics in the conditions of meadow and coastal- WATER plant communities of the steppe zone of Ukraine. The materials of the work were the original mycological collections performed as part of the mycological examination of thisterritory during 2008-2019 pp., аs well as materials from the herbarium of the Institute of Botany named after M. Kholodny National Academy of Sciences of Ukraine (KW). Collection, herbarization and identification of samples were performed according to generally accepted methods of cameral processing of micromycetes. To establish the taxonomic affiliation of species, the method of light microscopy was applied. As a result of our research, the species diversity of Dothideomycetes has been established, which includes 32 species from 13 genera, 9 families, 2 orders of 2 subclasses. The characteristic features of the taxonomic structure of the studied mycobiota are the predominance of representatives of Pleosporales (30 species), the family Leptosphaeriaceae, and the genus Leptosphaeria (10 species). Herbotrophs associated with herbaceous plants (representatives of the genera Leptosphaeria, Pleospora, Ophiobolus, etc.) predominate in the ecological structure of the identified species composition. Identified species of fungi are form consortia with 35 species of higher plants from 25 genera of 16 families, with a largest number of micromycetes observed on plants of the Asteraceae. A variety of phytocenotic conditions of communities and the composition of substrate plants are influenced by the formation of distinctive species complexes of Dothideomycetes
Dothideomycetes; species composition; taxonomic structure; meadow communities; coastal-water communities; steppe zon