Taxonomy and phylogeny of Lopharia s.s., Dendrodontia, Dentocorticium and Fuscocerrena (Basidiomycota, Polyporales)

Abstract Eleven taxa of Lopharia s.s., Dendrodontia, Dentocorticium and Fuscocerrena in Polyporales are included in the phylogenetic analyses of nuc rDNA ITS1-5.8S-ITS2 (ITS), D1-D2 domains of nuc 28S rDNA (28S) and RNA polymerase II second-largest subunit (rpb2) sequences. New species Lopharia resupinata and L. sinensis are described and illustrated. Lopharia resupinata, from south-eastern China, is closely related to L. ayresii, and L. sinensis, from northern China, is related to L. cinerascens and L. mirabilis. Lopharia mirabilis specimens from temperate to tropical areas with varied hymenophore configurations all cluster together in a fully supported clade. Dendrodontia and Fuscocerrena are shown to be synonyms of Dentocorticium, which is phylogenetically related to Lopharia. Four new combinations, Dentocorticium bicolor, D. hyphopaxillosum, D. portoricense and D. taiwanianum, are proposed. Revised generic descriptions of Lopharia and Dentocorticium are provided with keys to the six accepted species in each genus. A list of all names in Lopharia and Dentocorticium are presented with their current taxonomic status. Type specimens of Dentocorticium brasiliense and D. irregulare were examined and determined to be later synonyms of Punctularia subhepatica and Diplomitoporus daedaleiformis, respectively.

Introduction and the Centre for Forest Mycology Research (CFMR). Samples for microscopic examination were mounted in 0.2 % cotton blue in lactic acid, 1 % phloxine and Melzer's reagent. The following abbreviations are used: L = mean spore length, W = mean spore width, Q = L/W ratio, n (a/b) = number of spores (a) measured from given number of specimens (b). Colour codes and names follow Kornerup and Wanscher (1978).
DNA extraction and sequencing. A CTAB plant genome rapid extraction kit-DN14 (Aidlab Biotechnologies Co. Ltd, Beijing) was employed for DNA extraction and PCR amplification from dried specimens. The ITS, 28S and rpb2 gene regions were amplified with the primer pairs ITS5 and ITS4 (White et al. 1990), LR0R and LR7 (http://www.biology.duke.edu/fungi/mycolab/primers.htm) and rpb2-f5F and rpb2-7.1R (Liu et al. 1999, Matheny et al. 2007), respectively. The PCR procedures for ITS and 28S followed Liu et al. (2017), while the procedure for rpb2 was the same as Justo and Hibbett (2011). DNA sequencing was performed at Beijing Genomics Institute and the sequences are deposited in GenBank (Table 1).
Maximum Likelihood (ML), Maximum Parsimony (MP) and Bayesian Inference (BI) analyses were performed by using RAxML 7.2.6 (Stamatakis 2006), PAUP* 4.0b10 (Swofford 2002) and MrBayes 3.1.2 (Ronquist and Huelsenbeck 2003), respectively. In ML analysis, statistical support values were obtained from rapid bootstrapping of 1000 replicates using default settings for other parameters. In MP analysis, gaps in the alignments were treated as missing data. Trees were generated using 100 replicates of random stepwise addition of sequence and tree-bisection reconnection (TBR) branch-swapping algorithm with all characters given equal weight. Branch supports for all parsimony analyses were estimated by performing 1000 bootstrap replicates (Felsenstein 1985) with a heuristic search of 10 random-addition replicates for each bootstrap replicate. For BI, best models of evolution were estimated by using MrModeltest 2.2 (Nylander 2004) and the Bayesian posterior probabilities (BPP) were determined by Markov Chain Monte Carlo sampling in MrBayes 3.1.2. Four simultaneous Markov chains were run for two million generations and trees were sampled every 100th generation. The first quarter of the trees, which represented the burn-in phase of the analyses, were discarded and the remaining trees were used to calculate posterior probabilities in the majority rule consensus tree.

Phylogeny results
The ITS-28S-rpb2 sequences dataset contained 54 ITS, 55 nuc 28S and 40 rpb2 sequences from 56 samples representing 38 ingroup and 2 outgroup taxa (Table 1). Twenty-three ITS, 25 nuc 28S and 11 rpb2 sequences were generated for this study ( Table 1). The dataset had an aligned length of 2806 characters, of which 836 were parsimony informative. MP analysis yielded four equally parsimonious trees (TL = 5240, CI = 0.323, RI = 0.594, RC = 0.192, HI = 0.677). The best model estimated and applied in the Bayesian analysis was GTR+I+G. MP and BI analyses resulted in almost the same tree topologies as that of ML analysis, which is similar to that of Justo and Hibbett (2011). Only the ML tree is shown in Fig. 1  Diagnosis. Distinguished from other Lopharia species by its resupinate basidiocarps, a densely compact texture, a monomitic hyphal system and small basidiospores 7-9(-10) × 4-5 µm. Holotype. CHINA. Jiangxi Province: Anyuan County, Sanbaishan Forest Park, on fallen angiosperm branch, 15 Aug. 2016, He 4401 (holotype, BJFC 023842!).
Additional Remarks. Lopharia sinensis belongs to the L. cinerascens clade (Fig. 1). It differs from L. mirabilis by its smooth hymenophore surface and north temperate distribution and from L. cinerascens by its ellipsoid basidiospores and long, projecting cystidia (Hjortstam andRyvarden 1990, Dai 2002). Lopharia pseudocinerascens from Africa also belongs to the L. cinerascens group and can be distinguished from L. sinensis by narrower basidiospores (8-14 × 4.5-6.5 µm, Boidin and Gilles 2002).  (Fig. 1). They all develop the large encrusted cystidia, the large basidia (> 50 µm long) and the relatively large basidiospores (> 8 µm long and 4 µm wide) that characterise the genus. Lopharia mirabilis, the generic type, is a tropical species possessing a tuberculate, odontoid, irpicoid to semiporoid hymenophore (Hjortstam andRyvarden 1990, Dai 2002). The authors' phylogenetic analyses show that collections from temperate to tropical areas in China, with smooth to semiporoid hymenophores, cluster together, thus extending the geographical range and hymenophore variability for L. mirabilis (Figs 1, 5). Thus, specimens from Taiwan, previously identified as L. cinerascens Gilles 2002, Wu 2010) because of their smooth hymenophore, are in fact L. mirabilis. Lopharia cinerascens is a cosmopolitan species in temperate to subtropical areas (Hjortstam andRyvarden 1990, Boidin andGilles 2002). These phylogenetic analyses suggest that it is a species complex (Fig. 1). Two specimens (He 2188 and He 2228, Fig. 2F) from Wisconsin in northern United States are probably L. cinerascens s.s. for it is near the type locality of Pennsylvania. They are phylogenetically distinct from FP-105043 (listed as L. cinerascens in Justo and Hibbett, 2011) which was collected in Mississippi, southern United States.
Lopharia ayresii nests within the Lopharia clade and forms with L. resupinata a strongly supported lineage sister to the L. mirabilis group (Fig. 1). These two species have resupinate basidiocarps, a monomitic hyphal system, a thin to indistinct subiculum and a thickened subhymenium. Otherwise, they fit well with other Lopharia spe-cies in developing large basidia and basidiospores and encrusted cystidia. The addition of these species requires that the genus description of Lopharia be modified to include monomitic taxa.

Taxonomy of Dentocorticium, Dendrodontia and Fuscocerrena species
Dendrodontia bicolor (generic type, Fig. 6A), Fuscocerrena portoricensis (generic type, Fig. 6B), Dentocorticium sulphurellum, Dentocorticium taiwanianum ( Fig. 6C-D) and Dentocorticium ussuricum (Parmasto) M.J. Larsen & Gilb. (generic type, Fig. 6E-F) cluster in a strongly supported clade (Fig. 1). The phylogenetic analyses demonstrate that the three genera are closely related and support merging the genera together. Amongst the three generic names, Dentocorticium (1974) has priority over Dendrodontia (1980) andFuscocerrena (1982). Thus, the latter two genera are treated as synonyms of Dentocorticium and four new combinations are proposed. An expanded and more inclusive generic circumscription of Dentocorticium is presented below. Remarks. See Hjortstam and Ryvarden (1980) for a description and illustration of this species. The authors were unable to obtain sequences of Dentocorticium bicolor from the type locality in South Africa. Maekawa (1994) reported D. sulphurellum from Japan; however, the Japanese specimens may be D. bicolor, for D. sulphurellum appears to be restricted to North America. Remarks. Dentocorticium portoricense is easily recognised by its poroid, hydnoid to spinose, dark brown hymenophore and greenish-yellow hymenial surface. Phylogenetically, it is closely related to D. taiwanianum (Fig. 1). See Ryvarden (1982) for description and drawing of this species with synonymy. Remarks. This is a common species in tropical China. See Wang et al. (2010) for a description and illustration of this species.

List of names in Dentocorticium and their current taxonomic status
The list by species epithet is obtained from Index Fungorum (http://www.indexfungorum.org, 25 Sep. 2017). If a name is accepted, a direct statement is made with supporting evidence cited.