Application of succession approach for the investigations of the species composition of microfungi and fungal biomass in antarctic soilsстатья
Статья опубликована в журнале из списка RSCI Web of Science
Статья опубликована в журнале из перечня ВАК
Статья опубликована в журнале из списка Web of Science и/или Scopus
Дата последнего поиска статьи во внешних источниках: 27 января 2018 г.
Аннотация:The succession approach was applied to obtaining the maximal information on specific composition and structure of fungal biomass in the Antarctic soils samples subjected to prolonged storage at low temperatures and water deficit. Studies were carried out on soil samples with low level organic content (0.14% of carbon, 0.03% of nitrogen) from under the «cobblestone pavement» and with high level organic content (0.41% of carbon, 0.05% of nitrogen) from under the Ceratodon purpureus moss litter. After thawing each of samples was divided into two parts which were incubated to the current of 2 months at constant humidity (30% of the maximum soil water capacity) — one couple at 5°C, and the second one at 20°C. Soils were analyzed for the 1, 4, 7, 14, 30, 45 and 60th days. Studies into microfungal species composition were performed by inoculation on the Czapek’s medium at 5 and 25°C, while the structure of the fungal biomass was analyzed by fluorescence microscopy with calcofluor white (all fungal biomass), fluorescein diacetate (viable propagules) and ethidium bromide (dead cells) staining. The biomass was found to be characterized by predominance (up to 84%) of minute fungal spores (3 μm at maximum in diameter) and yeast. The biomass growth and the proportion of live propagules in it were greater at the lower temperature of 5°C than at 20°C. The biomass increasing was predominantly due to the reproduction of yeast. It was established that in the process of succession the number of the isolated microfungi was 2.5 to 3-fold greater than in the initial samples. The greatest increase in the species diversity was noted at the beginning of succession, i. e., on the 7th and 14th days. The greatest microfungal diversity was revealed in soils with lower content of organic matter. Abundance of species and micromycetes was to a great extent dependent on the plate incubation temperature rather than on the temperature of soil incubation. The greatest species diversity including that of eurytopic species (Aspergillus fumigatus, A. niger, A. versicolor, Epicoccum nigrum, Mortierella alpina, Penicillium spp., Sarocladium strictum) was noted at the elevated temperature of 25°C. Psychrotolerant species, such as Thelebolus microsporus and Goffeauzyma gilvescens were isolated only at 5°C. Seven species of micromycetes (Cadophora novi-eboraci, Coniothyrium glomeratum, Cryptendoxyla hypophloia, Eurotium niveoglaucum, Lecanicillium fungicola, Microascus cinereus, Simplicillium aogashimaense) isolated in the process of succession have never been noted in Antarctica before.Key words: microscopic fungi, soils, Antarctica, succession, structure of biomass, structure of species.