Fungi in Bottom Sediments of the Chukchi Sea

Abstract

We present the first study on the quantity and diversity of the mycobiota in bottom sediments of the Chukchi Sea. During implementation of the RUSALCA-2012 program, 22 samples of bottom sediments from depths of 44–110 m were collected in late August–early September 2012. Fungi were isolated on agarized media (salinity 35 psu, temperature 6°C). Species identification was performed by morphological-cultural and molecular-genetic methods based on the nucleotide sequences of ITS1-ITS2 rDNA. A total of 128 colonies of mycelial fungi were isolated; 0 to 22 propagules were obtained from each 1 cm³ sample. The overall diversity was represented by 48 morphotypes belonging to 32 genera in 15 orders of ascomycetes and basidiomycetes. Ascomycetes predominated both in number and diversity. A number of species were found in marine ecosystems for the first time. The taxonomic position of nonsporulating isolates (13% of the total) was established using molecular techniques. Among them, high diversity was observed in the orders Pleosporales and Helotiales (Ascomycota).