The dissertation is devoted to investigation of two very close in some respects families of the order Agaricales, namely Bolbitiaceae and Psathyrellaceae. The indicated families are a good example of the mushroom groups, the species composition, ecology and geography of which still require special research on the territory of Ukraine (and, to a large extent, in the world).
As result of study of own specimens, analysis of published data and treatment of herbarium collections there were found generally 62 species of the family Bolbitiaceae and 93 – Psathyrellaceae in Ukraine. More than 77% of current species composition of the family Bolbitiaceae was found for the first time in our country, and for the family Psathyrellaceae this figure is respectively 45%. The genera Cystoagaricus and Mythicomyces were collected for the first time in our country, and Coprinopsis pachysperma var. tetrasporus was described as the new taxon. It has been showed that the degree of study of the mushrooms of both families in Uktaine is rather close to that in Poland, and by their species composition our country occupies fairly isolated position among other european countries.
Both investigated families noticeably differ by their composition of ecological-trophic groups. There is typical the predominance of humus saprotrophs for Bolbitiaceae (79.6%), and among Psathyrellaceae prevail wood-rotting mushrooms (48.4%), dung-inhabiting mushrooms (22.6%) and humus saprotrophs (21,5%). As result of this it is characteristic for Bolbitiaceae the practically equal distribution in forest and grass plant communities, while the species of the family Psathyrellaceae prefer forest communities. The representatives of both families are also distributed differently in the various botanical-geographical regions of Ukraine. While the distribution of the most of Bolbitiaceae is conditioned mainly by zonal climatic peculiarities, then for Psathyrellaceae the composition of the forest plant communities is more important, and the climat plays the secondary role.
Results of geographical analysis have shown that for the family Bolbitiaceae is characterictic the predominance of the species of azonal by their character geographical elements, because its representatives are mainly humus saprotrophs and weakly connected to determinate vegetable zones. At Psathyrellaceae, on the contrary, the species of the zonal by its cahracter nemoral element have larger weight, because among them there are prevailing wood-rotting species being closely connected just with broadleaved forests. Simultaneously there are predominating the species with cosmopolitan or circumpolar distribution in Ukraine, that gives evidence of the migration character of the modern species composition of both families in our country.
The study of the evolutionary processes in both families demonstrated, that one of most characteristic for evolution of fruit-bodies of Bolbitiaceae and Psathyrellaceae features is the coprinoidization, which outside those families is registered only among Agaricaceae. It is a way of adaptation to severe natural conditions through the extreme acceleration of the ontogenesis of fruit-bodies. Judging by the rather local distribution of this phenomenon among agaricoid mushrooms it becomes possible only at a certain (and rather high) degree of evolutionary development of agaricomycetes. Just coprinoidization has palyed especially large role in the evolution of Psathyrellaceae, while the gasteromicetization was more important for Bolbitiaceae. It is noticeable that the evolutionary pathes of each of the families were considerably conditioned by biological peculiarities of their representatives, especially by their nutrition mode. Within every of them the development of fruit-bodies of several rather clearly outlined habitual types was observed, while they appeared independently one of another as result of convergence. The every such type apparently reflects the adaptation to rather clearly outlined set of ecological niches.
