| Wrightoporia accommodates a kind of wood-inhabiting polypores producing finely asperulate and amyloid basidiospores, and causing a white rot. Morphologically, species of Amylonotus, Amylosporus, Heterobasidion and Bondarzewia are similar to Wrightoporia. Phylogenetically, species of Amylonotus, Amylosporus, Heterobasidion and Bondarzewia grouped outside the Wrightoporia clade. Bondarzewia is a remarkable polypore genus for its huge poroid basidiocarps while Heterobasidion is one of the most intensively studied basidiomycetous genera. Some species of them are destructive forest pathogens or edible and medicinal mushrooms.39 species of Wrightoporia have been described or transferred from other genera; however, only a few species were referred to molecular phylogeny. So far, a comprehensive phylogeny of the genus Wrightoporia and related genera has not been determined.Here, we use internal transcribed spacer (ITS) and nuclear ribosomal large subunit (nLSU) seuqences and maximum likehood (ML), maximum parsimony (MP) and Bayesian inference (BI) analyses to infer the phylogenetic relationships of Wrightoporia species and related genera and the phylogenetic relationships of Bondawewia species. In addition, we utilize a multilocus phylogenetic approach and MP, ML and BI analyses to infer the phylogenetic relationships of Heterobasidion species.In this study, about 266 worldwide specimens of Wrightoporia and related genera are studied morphologically, and ITS regions and/or nLSU regions from 120 samples, representing 42 species, are sequenced for phylogenetic analysis. Six clades of Wrightoporia sensu lato (s.l.) were recognized. The Wrightoporia sensu stricto (s.s.) clade includes W. avellanea, W. lenta (the generic type), and W. subavellanea. Three clades segregating from Wrightoporia s.s. are proposed as three new genera, Larssoniporia gen. nov., Pseudowrightoporia gen. nov., and Wrightoporiopsis gen. nov. Two clades were named as Amylonotus and Amylosporus. Bondarzewia and Heterobasidion species were embedded in the Bondarzewiaceae clade. Based on both phylogenetic and morphological evidence, previously treated species in Wrightoporia are respectively transferred to Amylonotus, Amylosporus, and the above three new genera, or retain in Wrightoporia as members of Wrightoporia s.l. because of no good solution for these species so far. In addition, one new species in Larssoniporia, three new species in Pseudowrightoporia, and two new species in Wrightoporiopsis are proposed based on both molecular and morphological data.Two species, Bondarzewia berkeleyi and B. mesenterica, were commonly reported in Europe and North America. However, the genus is not well known outside North America and Europe. Based on samples from the typical areas of all described species, covering the currently known distribution range of Bondarzewia in the world, we explored the phylogeny and species diversity of Bondarzewia. Our combined ITS and nLSU dataset included 21 samples represented by 21 ITS and nLSU sequences. In the present study, three new combinations are proposed, B. dickinsii, B. propria and B. retipora, and three new species, B. kirkii, B. occidentalis and B. submesenterica are proposed.According to the genealogy of ITS-nrLSU-RPB2-RPB1-GAPDH-ATP6-mtSSU (the internal transcribed spacer-the large nuclear ribosomal RNA subunit-the largest subunit of RNA polymerase II-the second subunit of RNA polymerase I-glyceraldehyde 3-phosphate dehydrogenase-mitochondrial ATP synthase subunit 6-mitochondrial small subunit rDNA) combined loci, Heterobasidion spp. was a monophyletic group that consisted of three lineages. It was infered that so called Eur P/Nam P-group of H. annosum complex is more closely related to the H. insulare complex than to the Nam S/Eur S/Eur F-group of H. annosum complex. Moreover, Heterobasidion araucariae seemed to be a member of the H. insulare complex. Thus, the definitions of H. annousum/H. insulare complex are challenging.In total, based on morphological and phylogenetic studies, three new genera and fourteen new species, are described; three new Chinese records are found; and twenty new combinations and a synonymy species are proposed. Species in Bondarzewia are distinguished from species in Wrightoporia mainly by their larger basidiocarps, simple septate generative hyphae and bigger basidiospores. Heterobasidion separates from Wrightoporia by its simple septate generative hyphae and non-amyloid basidiospores. Wrightoporia s.s. differs from other related genera by its soft and cottony basidiocarps when fresh, membranous to cottony basidiocarps when dry, margin usually with rhizomorphs, and distinctly narrow tramal skeletal hyphae (0.8-2.5 μm). The texture of fruitbody and the type of rough texture of basidiospore surface are the important character for indetification at generic level. Among Wrightoporia clade, morphological characters, such as the growth habit, the color, size and thickness of fruitbody, the texture, shape and size of pores, presence or not of clamp connections and (or) simple septa, presence or not of dextrinoid reaction of skeletal hyphae, presence or not of rhizomorphs, gloeoplerous hyphae, cystidia and gloeocystidia and shape and size of basidiospores, substrata and distribution are the important character for indetification at species level. |
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