Mycological Progress (2018) 17:357–364 https://doi.org/10.1007/s11557-017-1362-5 ORIGINAL ARTICLE Purpureocorticium microsporum (Basidiomycota) gen. et sp. nov. from East Asia Sheng-Hua Wu1 & Dong-Mei Wang2 & Yu-Ping Chen1 Received: 25 July 2017 /Revised: 8 November 2017 /Accepted: 13 November 2017 /Published online: 25 November 2017 # German Mycological Society and Springer-Verlag GmbH Germany, part of Springer Nature 2017 Abstract A corticioid fungal species found in mountainous Taiwan, and Yunnan Province of China, is described as a new genus and new species: Purpureocorticium microsporum (Agaricomycetes, Basidiomycota). Morphological study and phylogenetic analyses based on sequence data respectively derived from the large subunit nuclear ribosomal RNA gene (LSU nrDNA) alone and the combined dataset of LSU nrDNA and translation elongation factor 1-α gene (tef1-α) indicated that Purpureocorticium does not belong to any clade of the Agaricomycetes. Purpureocorticium and P. microsporum are characterized by having a resupinate basidiocarp with smooth hymenial surface which turns purple in KOH, and becomes purplish after storage, micro- scopically having compact texture of subiculum, nodose-septate thin-walled generative hyphae, absence of cystidia, basidia subclavate with a median constriction, or utriform, bearing ovate-ellipsoid small-sized basidiospores, which are smooth and thin- walled, inamyloid, and nondextrinoid. The new combination Rhizochaete rubescens is proposed, based on morphological and phylogenetic evidences. Keywords China . New genus . New species . Taiwan . Taxonomy Yunnan Province of China. These corticioid fungal specimens were collected from dead angiosperm branches or on rotten trunks. The hymenial surface of this species is white when Introduction fresh, turning purple in KOH. On the other hand, its hymenial surface becomes purplish pink or pinkish purple after storage Corticioid fungi are members of Agaricomycotina, mainly of several years. Its microscopic features do not exactly fit the with resupinate basidiocarps. Evidence from molecular stud- concept of any known corticioid genera. The present study ies revealed that corticioid taxa are present in all major clades based on morphological characteristics and phylogenetic anal- on Agaricomycetes (Binder et al. 2005, 2010;Wuetal.2007; yses of DNA sequences inferred from the large subunit nucle- Larsson 2007). These studies also showed that it is barely ar ribosomal RNA gene (LSU nrDNA) alone and the com- possible to evaluate their order and family rank for a great bined dataset of LSU nrDNA and the translation elongation portion of the corticioid genera, based merely on studying factor 1-α gene (tef1-α) has revealed that these collections macro- and microscopic characters. represent a new genus and new species. In the survey of corticioid fungi in Taiwan and mainland China over two decades, an unfamiliar species has been col- lected several times in mountainous Taiwan, and also once in Materials and methods Section Editor: Yu-Cheng Dai Morphological and cultural studies * Sheng-Hua Wu Macro- and microscopic studies were based on dried speci- [email protected] mens. Thin free-hand sections of basidiocarps were prepared 1 Department of Biology, National Museum of Natural Science, for microscopic study. For observations and measurements of Taichung 404, Taiwan, Republic of China microscopic characters, the sections were mounted in 5% ’ 2 Department of Pharmacology, University of Illinois, KOH to ensure rehydration. Melzer sreagentwasappliedto Chicago, IL 60612, USA detect amyloidity and dextrinoidity. Cotton blue was used as a 358 Mycol Progress (2018) 17:357–364 mounting medium to determine cyanophily. The following heuristic search with 1000 random taxa stepwise addition se- abbreviations were used for basidiospore measurements: L = quences, TBR branch swapping, and MAXTREES set to mean spore length with standard deviation, W = mean spore autoincrease. All transformations were considered unordered width with standard deviation, Q = variation in L/W ratio, n = and equally weighted, with gaps treated as missing data. number of spores measured from each specimen. Living Calocera cornea was used as the outgroup for rooting pur- mycelia were isolated from the woody substratum beneath pose. The relative robustness of the clades was assessed by the the basidiocarps and grown on 1.5% malt extract agar. All bootstrap method (Hillis and Bull 1993) using 1000 heuristic studied fungal specimens and living cultures are deposited in search replicates with random taxa stepwise addition se- the herbarium of the National Museum of Natural Science of quences and TBR branch swapping with MAXTREES set to the Republic of China (TNM). autoincrease. Cultural descriptions and the species code follow Nobles For the Bayesian analysis, MrModeltest 2.3 (Nylander (1965), with amendments by Boidin and Lanquetin (1983). 2004) was used to determine the best-fit evolution model for Nobles’ code as detailed by Nakasone (1990) was adopted each dataset for Bayesian inference (BI). BI was calculated in this study. General methods of cultural studies have been with MrBayes3.1.2 with the K2 + I + G model (Ronquist and previously described by Wu (1996). Huelsenbeck 2003). The Markov chain Monte Carlo search was run with four chains for 500,000 generations, with trees Phylogenetic analyses sampled every 100 generations, and the average standard de- viation of split frequencies was below 0.05. According to Hall The sampling of representative orders and clades of (2004), the option of burnin was set to discard 10% trees. Agaricomycetes for the analyses of LSU nrDNA alone and a Branches that received bootstrap support for maximum parsi- combined dataset of LSU nrDNA and tef1-α sequences has mony (MP) and Bayesian posterior probabilities (BPPs) great- consulted some phylogenetic studies (Binder et al. 2005, er than or equal to 75% (MP) and 0.95 (BPP) were considered 2010, 2013; Hibbett 2006; Larsson 2007; Wu et al. 2007, as significantly supported, respectively. 2010; Li and Cui 2013). In addition, resemblance of the chief morphological characteristics of the presented new taxon was also considered for choosing the genera and species included Results in the analyses. The analyzed species and strains in both anal- yses, though not totally the same, nevertheless represented Phylogenetic analyses closely related taxa. The taxa and strains sampled are listed in Table 1. The LSU nrDNA amplification delimited by the primer pair The material for DNA isolation was taken from mycelia LR0R/LR5 yields PCR products of ca. 920 bp long. The final grown on malt extract agar (MEA). The samples were alignment of 38 sequences included 2171 positions. After ex- ground into fine powder with a pestle and mortar. DNA cluding ambiguous sites at both ends, 902 alignment sites was extracted from the fine powder using the Plant were used for the phylogenetic analysis. The MP analysis Genomic DNA Extraction Miniprep System (Viogene, revealed five most parsimonious trees [1330 steps, consisten- Taiwan), according to the manufacturer’s instructions. cy index (CI) = 0.4, retention index (RI) = 0.425]. Of the 902 The primer pair LR0R/LR5 was used to amplify the LSU included sites, 549 were constant, 106 were variable but par- nrDNA region. Part of tef1-α was amplified with primer simoniously uninformative, and 247 sites were parsimony in- pair EF1-1953R and Efdf (http://www2.clarku.edu/faculty/ formative. The best model for the combined LSU nrDNA dhibbett/Protocols_Folder/Primers/Primers.pdf). The dataset estimated and applied in the Bayesian analysis is: protocol for polymerase chain reaction (PCR) amplifica- K2+I+G,lsetnst=2,rates=invgamma;prsetstatefreqpr= tion followed Wu et al. (2007). PCR products were purified dirichlet (1,1,1,1). Bayesian analysis resulted in a similar to- with the PCR-M Clean Up system (Viogene). Nucleotide pology as MP analysis, with an average standard deviation sequences were determined from both strands using the (SD) of split frequencies = 0.023842 (BI). ABI PRISM BigDye Terminator Cycle Sequencing One of the most parsimonious trees is shown in Fig. 2.In Ready Reaction Kit on an ABI 3730 DNA sequencer total, 22 clades were recognized from the ingroup taxa: (Perkin Elmer, Applied Biosystems, Foster City, CA). Agaricales, Amylocorticiales, antrodia clade, Atheliales, All sequences included in the analyses were aligned and Boletales, Cantharellales, Corticiales, grifola clade, adjusted manually in BioEdit 7.0.4.1 (Hall 1999). The opti- gelatoporia clade, Gloeophyllales, Gomphales, mized sequence dataset (deposited in TreeBASE: http://purl. Hymenochaetales, Jaapiales, core polyporoid clade, phlebioid org/phylo/treebase/phylows/study/TB2:S21019?x-access- clade, phlebiella clade, residual polyporoid clade, Russulales, code=b08363e7ba49950c7d3d98d90465b73f&format=html) Thelephorales, Trechisporales, tyromyces clade, and was analyzed in PAUP* 4.0b10 (Swofford 2002)using Purpureocorticium. In the phylogenetic tree (Fig. 2), the two Mycol Progress (2018) 17:357–364 359 Table 1 Taxa used in this study, along with their strain/specimen Species Strain or specimen no. GenBank accession no. numbers and GenBank accession numbers. Newly generated LSU nrDNA tef1-α sequences are shown in bold Athelia arachnoidea CBS:418.72 GU187557 GU187672 Botryobasidium sp. Wu 1207-59 MF110286 LC270916 Calocera cornea AFTOL-ID 438 AY701526 AY881019 Ceraceomyces eludens JS27202 AF090878 – Ceraceomyces tessulatus KHL8474