Taxonomy And Phylogeny Of Fomitopsis And Related Genera In China

Fomitopsis is a cosmopolitan polypore genus, which was set up in the early 19th century, and it causes a brown rot and plays an important role in degradation of reduction in the forest ecosystem. Daedalea and Piptoporus are the related genera of Fomitopsis. Many new species had been described in or transferred to Fomitopsis since it was established, which led to the increase of the taxonomic characters of the genus. Previous phylogenetic studies showed Fomitopsis and Piptoporus were not monophyletic and the genetic relationships between Fomitopsis and its related genera and within species of each genus were unclear. Therefore, it is necessary to carry out taxonomic and phylogenetic studies by comprehensive samples, and such studies have important theoretical significance.Taxonomic and phylogenetic studies on the Chinese Fomitopsis and related genera were carried out. The studied specimens were mainly collected by myself and the team of the Institute of Microbiology, Beijing Forestry University in recent 15 years. Based on the internal transcribed spacer (ITS) regions, the nuclear ribosomal large subunit RNA gene (nLSU), the nuclear ribosomal small subunit RNA gene (nSSU), the mitochondrial small subunit RNA gene (mtSSU), the translation elongation factor 1-a gene (tefl) and the RNA polymerase II second-largest subunit RNA gene (rpb2), Maximum Likehood (ML), Maximum Parsimony (MP) and Bayesian Inference (BI) analyses were carried out to infer the phylogenetic relationships of Fomitopsis and related genera.The molecular phylogenetic analyses inferred from the combined multi-gene datasets of ITS+nLSU+rpb2 and ITS+nLSU+nSSU+mtSSU+tefl+;rpb2 showed that Fomitopsis and related genera were clustered in antrodia clade, and formed multiple subclades. Species previously belonging to Fomitopsis sensu lato were embedded in six subclades:Fomitopsis sensu stricto subclade (including the type species, F.pinicola), Fragifomes subclade, Niveoporofomes subclade, Rhodofomes subclade, Rubellofomes subclade and Ungulifomes subclade. Species of Daedalea formed a separate monophyletic subclade. Piptoporus sensu lato included species belonging to three distinct subclades: Fomitopsis betulina (=P. betulinus) subclade, Buglossoporus subclade and Piptoporellus subclade. The type of Piptoporus, F. betulina, nested in the Fomitopsis sensu stricto, so Piptoporus is treated as a synonym of Fomitopsis.In the present study, five new genera were set up:Fragifomes, Niveoporofomes, Rubellofomes, Piptoporellus and Ungulidaedalea. Nine new species were discovered:Buglossoporus eucalypticola, Daedalea allantoidea, Fomitopsis cana, F. subtropica, Piptoporellus hainanensis, P. triqueter, Rhodofomes subfeei, Rubellofomes cystidiatus and Ungulidaedalea fragilis. One new Chinese record species was found:Rhodofomes incarnatus. Nine new combinations were proposed:Fomitopsis betulina (= Piptoporus betlinus), Fragifomes niveomarginatus (=Fomitopsis niveomarginata), Piptoporellus soloniensis (= Piptoporus soloniensis), Rhodofomes cajanderi (= Fomitopsis cajanderi), Rhodofomes incarnatus(=Fomitopsis incarnata), Rhodofomes rosea (=Fomitopsis rosea), Rhodofomes subfeei (= Fomitopsis subfeei), Rubellofomes cystidiatus (= Fomitopsis cystidiata) and Ungulidaedalea fragilis (=Fomitopsis fragilis).The illustrated descriptions of 24 species in Fomitopsis and related genera from China were given, and the host and distribution of each species were supplied. Based on morphological and phylogenetic studies, the mian taxonomic conclusions of Fomitopsis and related genera are as follows:Fomitopsis sensu stricto differs from other related genera by its corky, tough to woody, mostly sessile basidiocarps, poroid hymenophores, white to greyish or straw-coloured context, a dimitic hyphal system in most species, and cylindrical to ellipsoid basidiospores. The shape and texture of fruiting body, the shape of hymenophores, the colour of context, the structure of hyphal system, and the shape of basidiospores are the important characters for indetification at generic level; ITS and rpb2 are the most suitable gene loci. The ecological habit, the features of fruiting body (the color, crust, cuticle, zonate, sulcate, velutinate etc.), the pores (shape and size), the structure of hyphal system, the wall thickness of skeletal hyphae, presence or absence of cystidia and cystidioles, and the shape and size of basidiospores are the important characters for indetification at species level.