Phylogenetic analysis and morphological characteristics of laccate Ganoderma specimens in Finland

The Ganoderma lucidum complex includes fungi with similar morphologies but which are thought to represent different species. The lack of available type material and associated absence of multiple locus sequence data has complicated identification of these fungi. The aim of this study was to clarify the identity of the laccate Ganoderma species occurring in Finland by inferring a phylogeny using DNA sequences from available boreal-temperate material. DNA from Finnish isolates together with an older G. lucidum isolate originating from the United Kingdom was sequenced, and the morphological features of the Finnish specimens were examined. The phylogenetic analysis of the internal transcribed spacer region (ITS), the elongation factor 1-alpha (tef1), RNA polymerase II subunit (rpb2), and partial beta-tubulin (beta-tub) genes revealed that the G. lucidum isolate from the United Kingdom did not fall within a well-supported clade with other G. lucidum sequences or related species. The Finnish isolates were closely related to the G. tsugae lineage in tef1, rpb2, and beta-tub phylogenies. However, G. tsugae appears morphologically distinct from the Finnish material. The results suggest that G. tsugae, or a species phylogenetically closely related to it, may occur in Finland. But further investigation into the relationship between G. tsugae and G. lucidum from Europe will be needed to clarify the identity of the laccate Ganoderma species in Finland.