Microfungi associated with withering willow wood in ground contact near Syowa Station, East Antarctica for 40 years

Abstract

Data are rather lacking on the diversity of microfungi associated with exotic plant substrates transported to continental Antarctica. We examined the diversity and species composition of microfungi associated with withering woody shoots of saplings of Salix spp. (willows) transplanted and in ground contact near Syowa Station, East Antarctica for more than 40 years. The willow saplings originated from Hokkaido, Northern Japan, and were experimentally transplanted in 1967–1968, but died within a few years. Dead willow shoots, unbranched and standing on bare ground for approximately 50 years, were used for the isolation of fungi with the surface disinfection method. A total of 43 isolates were retrieved from 32 (78 %) of the 41 shoots tested. The fungal isolates were classified into 18 molecular operational taxonomic units (MOTUs) based on the similarity of rDNA ITS sequences at the 97 % criterion. Leotiomycetes was the most common class in terms of the number of isolates and MOTUs, followed by Dothideomycetes, Sordariomycetes, and Eurotiomycetes. Molecular phylogenetic affinities suggested that the closest relatives of the MOTUs were saprobic and root-associated fungi. The result of the present study suggested that Cadophora luteo-olivacea is widespread in soils throughout Antarctica and likely indigenous.