An arctic community of symbiotic fungi assembled by long-distance dispersers: Phylogenetic diversity of ectomycorrhizal basidiomycetes in Svalbard based on soil and sporocarp DNA

• Published in: Journal of Biogeography
• Main Authors: Geml, József, Timling, Ina, Robinson, Clare H., Lennon, Niall, Nusbaum, H. Chad, Brochmann, Christian, Noordeloos, Machiel E., Taylor, D. Lee
• Format: Article in Journal/Newspaper
• Language: English
• Published: 2012
• Subjects: Arctic; Biodiversity; Climate change; Dispersal; Fungi; Gene flow; ITS rDNA; Long-distance dispersal; Migration; Phylogeography; Svalbard; Arctic Archipelago; Arctic biodiversity
• Online Access: https://research.manchester.ac.uk/en/publications/8f750577-aeb1-4264-a21f-8ae2b130a3fc; https://doi.org/10.1111/j.1365-2699.2011.02588.x

Aim Current evidence from temperate studies suggests that ectomycorrhizal (ECM) fungi require overland routes for migration because of their obligate symbiotic associations with woody plants. Despite their key roles in arctic ecosystems, the phylogenetic diversity and phylogeography of arctic ECM fungi remains little known. Here we assess the phylogenetic diversity of ECM communities in an isolated, formerly glaciated, high arctic archipelago, and provide explanations for their phylogeographic origins. Location Svalbard. Methods We generated and analysed internal transcribed spacer (ITS) nuclear ribosomal DNA sequences from both curated sporocarp collections (from Svalbard) and soil polymerase chain reaction (PCR) clone libraries (from Svalbard and the North American Arctic), compared these with publicly available sequences in GenBank, and estimated the phylogenetic diversity of ECM fungi in Svalbard. In addition, we conducted coalescent analyses to estimate migration rates in selected species. Results Despite Svalbard's geographic isolation and arctic climate, its ECM fungi are surprisingly diverse, with at least 72 non-singleton operational taxonomic units (soil) and 109 phylogroups (soil + sporocarp). The most species-rich genera are Thelephora/Tomentella, Cortinarius and Inocybe, followed by Hebeloma, Russula, Lactarius, Entoloma, Sebacina, Clavulina, Laccaria, Leccinum and Alnicola. Despite the scarcity of available reference data from other arctic regions, the majority of the phylogroups (73.4%) were also found outside Svalbard. At the same time, all putative Svalbard 'endemics' were newly sequenced taxa from diverse genera with massive undocumented diversity. Overall, our results support long-distance dispersal more strongly than vicariance and glacial survival. However, because of the high variation in nucleotide substitution rates among fungi, allopatric persistence since the Pliocene, although unlikely, cannot be statistically rejected. Results from the coalescent analyses suggest recent gene flow ...