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We assessed soil fungal diversity at two sites on Deception Island, South Shetland Islands, Antarctica using DNA metabarcoding analysis. The first site was a relatively undisturbed area, and the second was much more heavily impacted by research and tourism. We detected 346 fungal amplicon sequence variants dominated by the phyla Ascomycota, Basidiomycota, Mortierellomycota and Chytridiomycota. We also detected taxa belonging to the rare phyla Mucoromycota and Rozellomycota, which have been difficult to detect in Antarctica by traditional isolation methods. Cladosporium sp., Pseudogymnoascus roseus, Leotiomycetes sp. 2, Penicillium sp., Mortierella sp. 1, Mortierella sp. 2, Pseudogymnoascus appendiculatus and Pseudogymnoascus sp. were the most dominant fungi. In addition, 440,153 of the total of 1,214,875 reads detected could be classified only at the level of Fungi. In both sampling areas the DNA of opportunistic, phytopathogenic and symbiotic fungi were detected, which might have been introduced by human activities, transported by birds or wind, and/or represent resident fungi not previously reported from Antarctica. Further long-term studies are required to elucidate how biological colonization in the island may be affected by climatic changes and/or other anthropogenic influences.

The Sematophyllaceae s.l. (Sematophyllaceae + Pylaisiadelphaceae) is a family of pleurocarpous mosses that is widely distributed throughout the globe, with centers of diversity in tropical forests. The circumscriptions of the family and its genera have been unstable, due to reductions in morphological complexity and alternative weightings of discrete morphological traits. Based on a sample spanning much of the generic diversity of the family, we inferred the phylogenetic relationships within the Sematophyllaceae s.l. from the variation in eight molecular markers from all three genomes (nuclear, mitochondrial, chloroplast). The Sematophyllaceae s.l. was resolved as monophyletic, as was the Sematophyllaceae s.str.; whereas the Pylaisiadelphaceae was found to be paraphyletic, although its monophyly could not be rejected. The morphological definition of the Pylaisiadelphaceae remains dubious, in the absence of unambiguous synapomorphies. The relationships of the clades of Pylaisiadelphaceae and Sematophyllaceae are discussed with respect to the circumscription of morphogenera, with a focus on the Sematophyllaceae crown clade (Aptychopsis, Chionostomum, Colobodontium, Donnellia, Macrohymenium, Paranapiacabaea, Pterogoniopsis, Rhaphidorrhynchium, Schroeterella, Sematophyllum, Warburgiella). Most genera of Sematophyllaceae were resolved as polyphyletic (e.g., Acroporium, Donnellia, Schroeterella, Sematophyllum, Trichosteleum) indicative of severe homoplasy in their putative diagnostic traits. We propose 4 new genera (Brittonodoxa, Microcalpe, Pocsia, Vitalia) and 19 new

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