Possible multiple introductions of Cladonia borealis to King George Island

摘要

Many lichens have extensive distributional ranges covering several climatic zones and are able to colonize extreme habitats, including high alpine and polar regions. Cladonia borealis, one of the dominant lichen species on King George Island, is a cosmopolitan species inhabiting polar, subpolar, and alpine areas. It is usually found on soil, humus, and mosses, and is morphologically highly diverse. To understand the phylogeographic history of C. borealis on King George Island, we compared specimens from there with specimens from Norway and Chile. We conducted phylogenetic and haplotype network analyses of the partial SSU, ITS1-5.8S-ITS2, and partial LSU rDNA sequences including intron sequences in LSU rRNA genes. Nuclear rDNA locus of C. borealis from King George Island was separated into two monophyletic lineages. It is suggested that they originated in multiple independent introduction events after long-distance dispersal from other continents.