Multi-Gene Phylogeny and Taxonomy of the Wood-Rotting Fungal Genus Phlebia sensu lato (Polyporales, Basidiomycota)

Phlebia s.l. (Polyporales, Basidiomycota) accommodates numerous species of wood-inhabiting fungi within the phylum Basidiomycota. The present study employs the morphological and phylogenetic approaches to revise the generic and species classification of Phlebia s.l. and surveys the species diversity. The phylogenetic analyses were performed using multiple gene regions viz. the internal transcribed spacer (ITS), the large subunit nuclear ribosomal RNA gene (nLSU), the translation elongation factor 1-α (tef1), the small subunit of mitochondrial rRNA gene (mtSSU), the glyceraldehyde 3-phosphate dehydrogenase (GAPDH), RNA polymerase II largest subunit (rpb1), and RNA polymerase II second largest subunit (rpb2). We overall recognize twenty genera of Phlebia s.l., including three new genera viz. Ceriporiopsoides, Phlebicolorata, and Pseudophlebia, seven new species viz. Crustodontia rhododendri, Hydnophlebia fissurata, Luteoporia straminea, Merulius sinensis, Mycoaciella brunneospina, Phlebia niveomarginata, and P. poroides and seventeen new combinations viz. Ceriporiopsoides guidella, C. lagerheimii, Hydnophlebia acanthocystis, H. capsica, H. fimbriata, Merulius fuscotuberculatus, M. nantahaliensis, M. tomentopileatus, Mycoacia tuberculata, Mycoaciella uda, Phlebicolorata alboaurantia, Ph. brevispora, Ph. pseudoplacenta, Ph. rosea, Pseudophlebia lindtneri, Ps. semisupina, and Ps. setulosa. Descriptions, illustrations, phylogenetic trees to show the placements, and notes of new taxa are provided.


Introduction
Taxonomy plays a significant role in revealing the diversity and classification of life and the discovery of specimens and observations into systems of names, in which it captures the relationships among taxa [1]. Fungi play a diverse and ecologically important role in the tree of life, in which the organisms exist in ecosystems mainly on wood, soil, leaves, rocks, and pelagic zones of the ocean [2]. Wood-rotting fungi are a cosmopolitan fungal group with a rich diversity in boreal, temperate, subtropical, and tropical vegetations, in which they degrade hard-to-digest substrates, such as lignin, cellulose, and pollen to push the sustainable ecosystem cycle [3,4]. The fungal order Polyporales Gäum. is a core group of the wood-rotting fungi located in the class Agaricomycetes Doweld (Basidiomycota R.T. Moore), which includes about 2500 species [5]. , Luteoporia 1 C per cycle), (4) extension at 72 • C for 2 min, (5) repeat for 6 cycles starting at step 2, (6) denaturation at 94 • C for 30 s, (7) annealing at 55 • C for 50 s, (8) extension at 72 • C for 1.5 min, (9) repeat for 34 cycles starting at step 6, (10) leave at 72 • C for 5 min. The PCR procedure for mt-SSU was as follows: initial denaturation at 94 • C for 2 min, followed by 36 cycles at 94 • C for 45 s, 52 • C for 45 s and 72 • C for 1 min, and a final extension of 72 • C for 10 min. The PCR procedure for GAPDH was as follows: initial denaturation at 95 • C for 3 min, followed by 35 cycles at 94 • C for 40 s, 50 • C for 45 s and 72 • C for 1 min, and a final extension of 72 • C for 10 min. The PCR procedure for RPB1 was as follows: (1) initial denaturation at 94 • C for 2 min, (2) denaturation at 94 • C for 40 s, (3) annealing at 60 • C for 40 s, (4) extension at 72 • C for 2 min, (5) repeat for 10 cycles starting at step 2, (6) denaturation at 94 • C for 45 s, (7) annealing at 55 • C for 1.5 min, (8) extension at 72 • C for 2 min, (9) repeat for 37 cycles starting at step 6, (10) leave at 72 • C for 10 min. The PCR procedure for RPB2 was as follows: (1) initial denaturation at 95 • C for 2.5 min, (2) denaturation at 95 • C for 30 s, (3) annealing at 52 • C for 1 min, (4) extension at 72 • C for 1 min (add 1 C per cycle), (5) repeat for 40 cycles starting at step 2, (6) extension at 72 • C for 1.5 min, (7) repeat for 40 cycles starting at step 6, (8) leave at 72 • C for 5 min. The PCR products were purified and directly sequenced at Kunming Tsingke Biological Technology Limited Company, Yunnan Province, China. All of the newly generated sequences were deposited in GenBank (Table 2).      Type specimens are indicated in bold. The new strains are indicated by an asterisk (*).

Figure 1.
Maximum Parsimony strict consensus tree illustrating the phylogeny of Phlebia sp and related genera in the order Polyporales based on ITS + nLSU sequences. Branches are la with BS > 70%, BT > 50% and BPP > 0.95, respectively. Clade names follow the previous stud Justo et al. [38]. The asterisks represent the type species.

Phylogenetic Analyses
In this study, 16 specimens belonging to Phlebia s.l. were newly examined and s quenced. From these 16 specimens, we generated one ITS, one nLSU, nine TEF1α, eleve RPB1, eight RPB2 and nine GAPDH sequences ( Table 2).
The first combined ITS + nLSU dataset ( Figure 1) comprises sequences from 117 spe imens and 105 species in Polyporales. The dataset had an aligned length of 1830 chara ters, of which 1019 characters were constant, 184 were variable and parsimony-unin formative, and 627 were parsimony-informative. Maximum parsimony analysis yielde 5000 equally parsimonious trees (TL = 7191, CI = 0.1972, HI = 0.8028, RI = 0.5284, RC 0.1042). The best model suggested by MrModeltest and applied in BI was GTR + I + G Bayesian analysis and ML analysis resulted in a similar topology as MP analysis; BI ha the average standard deviation of split frequencies = 0.008528 (BI), and the effective sam ple size (ESS) across the two runs is double that of the average ESS (avg ESS) = 479. Th phylogenetic tree inferred from ITS + nLSU sequences ( Figure 1) demonstrated seven m jor clades, the antrodia clade, core polyporoid clade, fragiliporia clade, gelatoporia clad phlebioid clade, residual polyporoid clade, and the tyromyces clade, for 106 sampled sp cies in Polyporales. The Phlebia s.l. species belonged to the phlebioid clade, in which Phl bia s.s. grouped with Merulius, Phlebicolorata, and Pseudophlebia with lower supports.
The second dataset based on ITS + nLSU + TEF1 + mt-SSU + GAPDH + RPB1 + RPB ( Figure 2) comprises sequences from 113 specimens and 65 species within the family Me uliaceae. The dataset had an aligned length of 5683 characters, of which 3061 characte were constant, 714 were variable and parsimony-uninformative, and 1908 were pars mony-informative. Maximum parsimony analysis yielded 48 equally parsimonious tree Maximum parsimony analysis was applied to the combined dataset and followed Zhao and Wu [64]; the tree construction procedure was performed in PAUP * version 4.0b10 [81]. All of the characters were equally weighted, and the gaps were treated as missing data. Trees were inferred using the heuristic search option with TBR branch swapping and 1000 random sequence additions. Max-trees were set to 5000, branches of zero length were collapsed, and all parsimonious trees were saved. Clade robustness was assessed using a bootstrap (BT) analysis with 1000 replicates [82]. Descriptive tree statistics tree length (TL), consistency index (CI), homoplasy index (HI), retention index (RI), and rescaled consistency index (RC) were calculated for each Maximum Parsimonious Tree (MPT) generated. Ready datasets were also analyzed using Maximum Likelihood (ML) with RAxML-HPC2 software through the Cipres Science Gateway (www.phylo.org (accessed on 10 August 2022)) [83]. Branch support (BS) for ML analysis was determined by 1000 bootstrap replicates. MrModeltest 2.3 [84] was used to determine the best-fit evolution model for each data set for Bayesian inference (BI) of the phylogeny. Bayesian inference was calculated with MrBayes 3.1.2 [85]. Four Markov chains were run for 2 runs from random starting trees for 5 million generations for the first dataset ( Figure 1), for 2 million generations for the second dataset ( Figure 2), and the trees were sampled every 100 generations; the first one-fourth of generations were discarded as burn-in. A majority-rule consensus tree of all remaining trees was calculated. Branches were considered as significantly supported if they received maximum likelihood bootstrap (BS) >70%, maximum parsimony bootstrap (BT) >50%, or Bayesian posterior probabilities (BPP) >0.95.

Phylogenetic Analyses
In this study, 16 specimens belonging to Phlebia s.l. were newly examined and sequenced. From these 16 specimens, we generated one ITS, one nLSU, nine TEF1α, eleven RPB1, eight RPB2 and nine GAPDH sequences ( Table 2).
The first combined ITS + nLSU dataset (  Notes-Morphologically, it was originally described under the genus Ceriporiopsis based on the character of the hard, brittle basidiomata with the cracking pore surface, a monomitic hyphal system with the clamped generative hyphae, a lack of cystidia and the absence of crystals, and cylindrical, colorless, thin-walled, smooth basidiospores. However, it forms a monophyletic lineage based on the molecular evidence in the previous studies [31,34,44] as well as the present study ( Notes-This species was found in Napo Province of Ecuador on the underside of a trunk of Alnus, and it was settled into Ceriporiopsis based on a monomitic hyphal system with the clamped generative hyphae, lack of cystidia and absence of the crystals and colorless, thin-walled, smooth basidiospores. In the present study, it groups with Ceriporiopsoides guidella, belonging to the genus Ceriporiopsoides ( Figure 2). Basidiomata resupinate is ceraceous to subceraceous. Hymenophore is grandinoid to odontioid or tuberculata, yellowish, brownish, or black hymenial surface, turning to reddish or purplish with KOH. The hyphal system is monomitic, having generative hyphae with clamp connections. Cystidia is cylindrical to ventricose. Basidia clavate has four sterigmata. Basidiospores ellipsoid to broadly ellipsoid, thin-walled, smooth, IKI-, CB- [86].
Distribution and ecology-The species is known from Yunnan Province, China, in a subtropical evergreen broad-leaved forest. It grows on moderately decayed angiosperm wood and causes a white rot.
Type species-Phlebicolorata brevispora (Nakasone) C.L. Zhao. Etymology-Phlebicolorata (Lat.): referring to the vivid hymenial surface. Basidiomata annual, resupinate. Hymenophore is tuberculata or poroid; the hymenial surface is vivid or bright-colored. The hyphal system is monomitic, having generative hyphae with clamp connections, IKI-, CB-; tissues becoming vinaceous brown to black in KOH. Basidiospores are colorless, thin-walled, smooth, and broadly ellipsoid to short cylindrical, which are acyanophilous, inamyloid, and non-dextrinoid. Notes-This species is characterized by the poroid basidiomata with apricot-orange to a dark orange surface with a reddish tinge and a monomitic hyphal structure having generative hyphae with clamp connections and ellipsoid, colorless, thin-walled, and smooth basidiospores [43]. In the present study, it groups into the genus Phlebicolorata based on the phylogenetic tree ( Figure 2) and we propose to transfer it to this genus as a new combination. Notes-Morphologically, it has tuberculata basidiomata with the light brownish olive hymenophore, a monomitic hyphal system, and ellipsoid to short cylindrical basidiospores [95], which size up the characters of Phlebicolorata. Phylogenetically, it nests into the genus Phlebicolorata and then groups with Phlebicolorata rosea (Figure 2). Notes-It is characterized by a poroid basidiomata having a reddish brown pore surface, a monomitic hyphal system with clamped generative hyphae, and broadly ellipsoid basidiospores [96]. Phylogenetically, it nests in the genus Phlebicolorata, in which it groups with Phlebicolorata alboaurantia (Figure 2). Notes-It has a poroid basidiomata with an orange-brown to reddish brown pore surface, a monomitic hyphal system having generative hyphae with clamp connections, and broadly ellipsoid basidiospores [44], which covers the characters of the genus Phlebicolorata. The present phylogeny supports it as a combination species inferred from the molecular evidence ( Figure 2). Etymology-Referring to be similar to genus Phlebia. Basidiomata annual, resupinate, hard, and brittle. Hymenophore is poroid or merulioid to hydnoid; the hymenial surface is pale ochraceous to ochraceous yellow-brown to reddish brown. The hyphal system is monomitic, having generative hyphae with clamp connections, IKI-, CB-; tissues unchanged in KOH. Cystidia present or not. Basidiospores are colorless, thin-walled, and smooth, IKI-, CB-.

Discussion
In the present study, an improved classification of Phlebia s.l. is provided by employing seven gene phylogenetic analyses at the intergeneric level (Figure 1), which discusses the circumscription and phylogenetic relationships of genera in Phlebia s.l. The tree topologies are generally consistent with previous phylogenetic studies using ribosomal RNA genes (rDNA) alone or in combination with the protein-coding genes [28,[31][32][33][34]38]. However, some minor differences still exist due to the different scales of sampling and lower supports for several topologies in this group.
Phylogenetically, Binder et al. [27] revealed that seven clades are found in the Polyporales viz. antrodia clade, core polyporoid clade, fragiliporia clade, gelatoporia clade, phlebioid clade, residual polyporoid clade, and the tyromyces clade. According to our results based on the combined ITS + nLSU sequence data (Figure 1), the species of Phlebia s.l. are nested into the phlebioid clade, which supports the previous scientific studies [31,34,38]. Three families viz. Phanerochaetaceae, Irpicaceae Spirin & Zmitr., and Meruliaceae P. Karst. were studied in the order Polyporales [97], in which the large-scale frame was put up for three families, and five genera of the family Meruliaceae were included, but the related scientific problem of Phlebia s.l. is still to be resolved.
Nilsson et al. revealed that in the International Nucleotide Sequence Databases, 10-21% of the 51,000 fungal ITS sequences available were annotated with incorrect taxonomic information [98]. More recently, this proportion has increased to almost 30% [99]. In the present study, we employed the type specimens and their sequences to carry out our phylogenetic tree for Phlebia s.l. (Figures 1 and 2), which increased the reliability of sequences supporting our results of Phlebia s.l.
In subclade I, eight genera, Crustodontia, Geesterania, Hydnophlebia, Luteoporia, Mycoaciella, Odoria, Phlebiporia, and Sarcodontia, were grouped together (Figure 2), similar to a previous study's topology [34]. The genus Crustodontia was proposed by Hjortstam and Ryvarden [88] to accommodate C. chrysocreas based on morphological data. In our analyses (Figure 2), Crustodontia is resolved as a monomitic hyphae system with strong support within the subclade I of Meruliaceae, in which the topology is similar to a previous study [34]. Two species, Crustodontia nigrodontea (C.L. Zhao & R.X. Huang) C.C. Chen & Sheng H. Wu and C. tongxiniana (C.L. Zhao) C.C. Chen & Sheng H. Wu, were transferred to Crustodontia mainly based on the phylogeny results [34]. In the present study, Crustodontia rhododendri is described as a new taxon of this genus based on the straw-to-ochraceous hymenial surface and the monomitic hyphal structure with clamped generative hyphae, and it groups with the type species C. chrysocreas. The species of Crustodontia, Geesterania, Luteoporia, Mycoaciella, and Phlebiporia are often classified in Phlebia s.l. based on their morphological similarities [14,16,31,53,58,72]. Two genera, Geesterania and Phlebiporia, nest into subclade I too, and group closely, as well as in a previous study [34]. Both genera share the similar character of turning reddish or purplish brown with KOH [72,86]. Morphologically, Geesterania is characterized by the dimitic hyphal system and the presence of the skeletocystidia, and additionally, it changes color when bruised or after drying [58]; phylogenetically, it groups with Phlebiporia based on the ITS + nLSU analysis in the previous studies [58,72], as well as the present study. Hydnophlebia nested within this clade as a monophyletic group with strong supports, including species from Africa, East Asia, Europe, and North America, with the typical characteristics of the membranaceous, reddish-orange basidiomata with poroid or grandinoid to hydnoid hymenophores, and, in addition, a distinctly rhizomorphic margin and a monomitic hyphal structure bearing simple-septate generative hyphae [34,100]. The monophyly of Hydnophlebia segregated from Phanerochaete s.l. was supported in the multi-gene phylogeny [28,61]. In the present study, Hydnophlebia fissurata nested into the genus Hydnophlebia and grouped with H. canariensis Telleria, M. Dueñas & M.P. Martín; morphologically, this species is characterized by a grandinoid hymenophore with a pale brown color, and a monomitic hyphal structure with simple-septate generative hyphae; therefore, we proposed it as a new taxon within Hydnophlebia. Luteoporia species were recorded from Asia (Luteoporia albomarginata This genus was proposed as a new genus in Polyporales based on morphological characters and molecular data [62], which is characterized by having poroid or odontioid to hydnoid hymenophores with golden yellow basidiomata turning purple with KOH [34,62]. In the present study, a new species Luteoporia straminea was found in Yunnan Province and is characterized by having odontioid, straw to pale orange hymenophores, and tissue that becomes reddish in KOH, and phylogenetically, it is sister to L. lutea, with high statistical supports ( Figure 2). Four species inside Luteoporia having a different macroscopical hymenophore with poroid or odontioid to hydnoid eye-attracting characters are phylogenetically clustered together closely within the genus Luteoporia, which suggests that the easily observing macroscopical hymenophore characters and the phylogenetical topology results are not similar; therefore, it needs deeper studies in the future. The genus Mycoaciella formed a monophyletic lineage (Figure 2), which is similar to the related research [34]. It was considered a synonym of Phlebia by several studies [14,76], but it was recently accepted as a separate genus [34,101]. In this study, Mycoaciella brunneospina grouped with M. bispora, but the morphological characters show that it has a monomitic hyphal system, which expands the generic concept extension. Odoria (Meruliaceae, Basidiomycota) was described as a new genus established for the threatened old-growth forest polypore Phaeolus alborubescens; morphologically, it has the special character of the pileate, with sappy basidiomata and thick-walled basidiospores [66], in which the morphological characteristics imply that it is incompatible with similar topology members from the molecular analysis. Sarcodontia is an old genus that was established in 1866 [102] with the type species of S. crocea (Schwein.) Kotl., which is unstable in phylogenetic analysis, perhaps for the lower supports. Recently, the separation of these genera from Phlebia s.l. has been supported by several mycologists mainly based on the phylogenetic characteristics [34,58], and our multi-gene phylogenetic analyses also supported this (Figure 2). Due to possessing variable hymenophore configurations, Phlebia s.l. is still highly polyphyletic with members distributed in three families viz. Phanerochaetaceae, Irpicaceae, and Meruliaceae [38,44], which reveal that the transitions between hymenophore or basidiocarp forms have evolved multiple times in the evolution of the phlebioid clade [28,97]; therefore, the molecular methods perhaps divide traditional taxonomic genera into several smaller genera.
In subclade II, three genera viz. Climacodon, Luteochaete, and Scopuloides formed a monophyletic lineage, in which the topology is similar to the previous studies [34,38,58]. The genus Climacodon originally was located in the family Climacodontaceae, but this family was a synonym of Meruliaceae; therefore, this genus was treated as a member of Meruliaceae [38], in which it grouped with Ceriporiopsis guidella and C. lagerheimii with low supports. The genus Luteochaete was established to accommodate Phanerochaete subglobosa Sheng H. Wu, which has subceraceous to coriaceous basidiocarps with a smooth hymenophore turning greenish yellow in KOH, simple-septate hyphae, and broadly el-lipsoid or subglobose basidiospores [34], and it is resolved as a monophyletic group with strong supports (Figure 2), as in a previous study [34]. Phlebia wuliangshanensis from Yunnan Province was conspecific with L. subglobosa [34], even though the specimens from both taxa are distant, perhaps all of them have the similar latitude and ecological environment. Scopuloides formed a well-supported group within Phlebia s.l. in the studies [34,38,58,66], and our molecular study also showed that it was a sister to Climacodon with lower supports (Figure 2).
In subclade III, the genus Ceriporiopsoides formed a single lineage with lower supports (Figure 2) with a similar topology to a previous study [34]. Ceriporiopsis guidella Bernicchia & Ryvarden and C. lagerheimii Laessøe & Ryvarden grouped together and formed a monophyletic lineage, in which both taxa nested among species of Ceriporiopsis and Phlebia solely [34,43,53,64]; morphologically both species have the unique characters of hard, brittle, cartilaginous basidiomata; therefore, in the present study, we propose a new genus Ceriporiopsoides to accommodate both species based on the morphological characters and molecular phylogeny (Figure 2).
In subclade IV, Hydnophanerochaete was recently built to comprise the type species H. odontoidea (Sheng H. Wu) Sheng H. Wu & C.C. Chen [60], and this species was originally described under the genus Phanerochaete [103]. According to the present molecular data, it nests into Phlebia s.l. (Figure 2) as in a similar phylogenetic result [34]. Phlebia ailaoshanensis was described from Yunnan, China, which was synonymized under H. odontoidea, even though the presence of little morphological differences; in addition, both species have overlapping geographic distributions in eastern Asia.
In subclade V, Mycoacia forms a single lineage (Figure 2) in the current study, and it was used to accommodate Phlebia-like species covering the characters of the odontioid to hydnoid hymenophore and a monomitic hyphal system [104], but later it was treated as a synonymy with Phlebia [13]. Our phylogenetical analysis ( Figure 2) suggests that it is a monophyletic genus, including the generic type species M. fuscoatra, as well as the previous study [34]. Ceriporiopsis gilvescens (Bres.) Domański is the type species of Ceriporiopsis Domański, and it was transferred to the genus Mycoacia as M. gilvescens (Bres.) Zmitr. [105] based on the phylogenetic analysis, but the lack of the type species of Ceriporiopsis makes it difficult to resolve the new location, so the taxonomy research about the species of Ceriporiopsis needs to arrange a schedule for mycologists.

Clade B
In subclade VI, Phlebia s.s. taxa grouped closely with Pseudophlebia [31,34,38], which is similar to our present analysis result (Figures 1 and 2). Due to the whole of Phlebia s.l. being highly polyphyletic, many species of Phlebia s.l. have been presently placed in other genera based on morphological and molecular characteristics. Therefore, the core taxa of Phlebia s.s. comprise P. acerina Peck, P. floridensis Nakasone & Burds, P. radiata, and P. rufa (Pers.) M.P. Christ. based on the molecular evidence. In the present study, Phlebia niveomarginata and P. poroides cluster into Phlebia s.s. (Figure 2), so we propose both of them to be new species.  [34] which is similar to this study ( Figure 2); additionally, all of them have the morphological characters of hard and brittle basidiomata with the pale ochraceous to ochraceous yellow-brown to reddish brown hymenial surface and mostly present cystidia; therefore, we describe a new genus Pseudophlebia to comprise them based on the morphological and molecular evidence.
In subclade VII, two genera Pappia and Phlebicolorata grouped together within this clade (Figure 2), but Pappia formed a single lineage, and morphologically, Pappia is characterized by the soft, pileate basidiomata with poroid hymenopores and the presence of chalmydospores, which is inconsistent with the species of Phlebicolorata [105]. Ceriporiopsis alboaurantia C.L. Zhao, B.K. Cui & Y.C. Dai was originally reported on the genus Ceriporiopsis based on the poroid basidiomata with a monomitic hyphal system with clamped generative hyphae and thin-walled basidiospores [43], in which it was sister to C. pseudo-placenta Vlasák & Ryvarden closely as well as in the study [64]. The species Ceriporiopsis rosea C.L. Zhao & Y.C. Dai was described within Ceriporiopsis, and it grouped with a clade comprising C. alboaurantia and C. pseudoplacenta [70]. Aurantiporus croceus (Pers.) Murrill was sister to C. pseudoplacenta [38]; four species Aurantiporus croceus, Ceriporiopsis alboaurantia, C. pseudoplacenta, and C. rosea grouped together closely and isolated from Aurantiporus or Ceriporiopsis [34] as well as the present study ( Figure 2); therefore, we propose a new genus of Phlebicolorata to accommodate them based on the morphological and molecular examination.

Clade C
In subclade VIII, Merulius formed a single lineage with a lower support (Figure 2), which is a different topology from a previous study [34]. The genus Merulius, typified by M. tremellosus Schrad., is characterized by the typical merulioid hymenophore, and it was considered a synonym of Phlebia based on morphological evidence [10], and due to the lack of enough morphological and molecular data, the previous study [34] put this genus inside Phlebia s.l. In the present study, we suggest this genus as a monophyletic genus based on the evidence of the morphological and molecular data ( Figure 2); in addition, the Index Fungorum (accessed on March 6, 2022) registers 525 records; therefore, it refrains from making more name changes. The species Merulius sinensis nests into the genus of Merulius and is a sister to M. nantahaliensis (Nakasone & Burds.) C.L. Zhao, so we propose it as a new species.

Clade D
In subclade IX, Phlebia centrifuga P. Karst. was found on a fallen trunk of Abies excelsa in Finland (1881), which is easily recognized by the characteristics of densely and irregularly papillose and partly radially or unevenly wrinkled hymenophore with whitish, fibrillosestrigose margin, and it was marginalized in the phylogenetical tree [34,38] as well as the present study (Figure 2), so a new genus of Hermanssonia Zmitr. was established [105].
Phlebia s.l. species are an extensively studied group, distributed worldwide [7,8,[13][14][15][16][17][27][28][29][30][32][33][34]106,107] and mainly found on hardwood, although a few species grow on coniferous wood [7,106]. Many species of Phlebia s.l. were found in America, Asia, and Europe, but most of them did not record in Africa and Oceania, in which we presumed that the specimens of Phlebia s.l. were undersampled by the mycologists. Research on the new taxa related to wood-decaying fungi of Phlebia s.l. from China have been reported [31][32][33]43,64,70,106], in which twelve Phlebia s.l. species were reported as new taxa recently. The macromorphology of fruiting bodies and hymenophore construction did not reflect the monophyletic result; therefore, focusing on the relationships between the host and Phlebia s.l. species may be very interesting in further deep studies. The studies on the molecular systematics of Phlebia s.l. also push the development of the Tree of Life, which will be useful to push further research on fundamental research and applied research of fungi. More and more species of Phlebia s.l. are found in subtropical and tropical Asia, especially they are reported in tropical China recently [3,4,106], and it is proved that this area has a unique ecological environment and many mycologists carry out studies in tropical Asia [4,[30][31][32][33]44,64,106].
In conclusion, our study conducted a basic survey on species diversity, generic recognition, and phylogeny of Phlebia s.l. (Meruliaceae) of Polyporales, especially in China, with many taxa sampling and much sequence data from ITS, nLSU, TEF1, mt-SSU, GAPDH, RPB1, and RPB2. Within Phlebia s.l., we overall recognize 20 genera, including three new ones, describing seven new species, and propose 17 new combinations. The status of some recognized genera and species can be further evaluated by phylogenetic or phylogenomic analyses based on more taxa and sequences. Based on the historical reason and the normal morphological characters of Phlebia s.l., so many similar taxa got together in this genus, and our present study is another brick in the wall of a house, which needs more and more mycologists to reel silk from cocoons and lift the veil for this genus in the future. Most of our new species in Phlebia s.l. were found in Yunnan Province, southwest China, a similar phenomenon was found in other groups of wood-rotting fungi [108][109][110][111][112]. The area is a hotspot for biodiversity, and more new taxa will be discovered after further investigations.