Dothideomycetes of meadow and coastal-water communities of the steppe zone of Ukraine

Abstract

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.

An inventory of biota components (including microscopic fungi) as a part of various natural biotopes of the steppe zone remains an urgent issue. The least surveyed at the moment are meadow and coastal-water communities. Under their heterogeneous conditions, one can expect the formation of rather peculiar species complexes of micromycetes, primarily those that are consortially associated with higher plants.The purpose of the article is to establish a species diversity of Dothideomycetes and its taxonomic structure in conditions of meadow and coastal-water 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 this territory during 2008-2019 pp., аs well as materials from the herbarium of theInstituteofBotanynamed 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. For the identification of species, the determinants and monographs of domestic and foreign authors were used (Sivanesan, 1984; Vasil’eva, 1987; Ellis, Ellis, 1987); species names are consistent with corresponding reference books and databases (Mosyakin, Fedorchuk, 1999; Index Fungorum, 2020).

As a result of our research,, the species diversity of Dothideomycetes has been established, which includes 32 species from 13 genera, 9 families,  orders Pleosporales and Capnodiales, subclasses Dothideomycetidae and Pleosporomycetidae. 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.

As a part of meadow communities, 19 species of loculoascomycetes from 8 genera of 4 families of the Pleosporales and Capnodiales orders are found. In halophytic meadow communities, 9 species of loculoascomycetes from 5 genera of 5 families of the order Pleosporales were found. In the coastal-water communities, 8 species of loculoascomycetes from 5 genera and 4 species families of the Pleosporales and Capnodiales orders were found. A variety of phytocenotic conditions of communities and the composition of substrate plants are influenced by the formation of distinctive species complexes of Dothideomycetes.

Thus, the species diversity of the Dothideomycetes of meadow and coastal-water communities of the steppe zone of Ukraine includes 32 species from 13 genera 9 families 2 orders of the Dothideomycetidae and Pleosporomycetidae subclasses. In its taxonomic structure, the leading members of the order Pleosporales (30 species) from the family Leptosphaeriaceae genus Leptosphaeria (10 species) play a leading role.

The Dothideomycetes species are form consortium connections with 35  species of vascular plants. In the ecological structure of mycobiota it was marked the dominance of herbotrophs species.

The direction of further research is the study of changes in taxonomic and ecological structures under the conditions of anthropogenic transformation of natural biotopes.