Research Article
Print
Research Article
Phylogeny and taxonomy of Nigroporus (Polyporales, Basidiomycota) with four new species from Asia and Oceania
expand article infoXiang-Lin Li‡, Yu-Cheng Dai‡, Zhan-Bo Liu‡, Yu-Han Jiang‡, Hong-Gao Liu§, Yuan Yuan‡
‡ Beijing Forestry University, Beijing, China
§ Zhaotong University, Zhaotong, China

Corresponding author: Yuan Yuan ( yuanyuan1018@bjfu.edu.cn )

Academic editor: Yupeng Ge
© 2025 Xiang-Lin Li, Yu-Cheng Dai, Zhan-Bo Liu, Yu-Han Jiang, Hong-Gao Liu, Yuan Yuan.
This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Citation: Li X-L, Dai Y-C, Liu Z-B, Jiang Y-H, Liu H-G, Yuan Y (2025) Phylogeny and taxonomy of Nigroporus (Polyporales, Basidiomycota) with four new species from Asia and Oceania. MycoKeys 112: 211-232. https://doi.org/10.3897/mycokeys.112.127011
Open Access

Abstract

Nigroporus vinosus (Berk.) Murrill, first described from North America, was considered to be a common species in China. The existence of a species complex is confirmed through a phylogenetic analysis of samples examined. Based on morphological examination and molecular evidence, four new species are described as Nigroporus australianus, N. austroasianus, N. subvinosus and N. yunnanensis. They are characterized by pileate, effused-reflexed to resupinate, purplish, vinaceous to brown basidiomata when fresh, mostly becoming brown when dry. Nigroporus australianus is characterized by narrower basidiospores measuring 3.4–4.1 × 1.3–1.5 µm, thicker contextual hyphae measuring 3.2–6.4 µm in diam and a geographical distribution in Australia. Nigroporus austroasianus is characterized by smaller pores measuring 10–13 per mm, generative hyphae dominant in the tube trama, small basidiospores measuring 3–4.1 × 1.5–2 μm and a distribution in Malaysia and tropical to subtropical regions of China. Nigroporus subvinosus is characterized by skeletal hyphae with thin to slightly thick walls, barrel- to pear-shaped basidia, and long cystidioles measuring 10–18 µm and is common in Asia. Nigroporus yunnanensis is characterized by thinner pilei measuring 2.5 mm thick at the base, bigger basidiospores measuring 4–4.5 × 1.9–2.2 μm and is found only in Yunnan. The 2-gene (ITS+nLSU) analysis of the Steccherinaceae indicated that the four new species nested in the Nigroporus clade. The 3-gene (ITS+nLSU+TEF1) analysis of the genus Nigroporus showed that N. australianus formed a monophyletic lineage, N. subvinosus was sister to N. austroasianus and N. yunnanensis, and N. austroasianus was sister to N. yunnanensis. Furthermore, N. vinosus sensu stricto is also distributed in Asia.

Key words

Biodiversity, molecular systematics, Steccherinaceae, taxonomy, wood-inhabiting fungi

Introduction

The genus Nigroporus (Steccherinaceae, Polyporales), typified by N. vinosus (Berk.) Murrill, was established by Murrill (1905). It is characterized by stipitate, pileate, effused-reflexed to resupinate, pinkish or violet to dark bluish gray basidiomata when fresh, a dimitic hyphal system with fuliginous skeletal hyphae and clamped generative hyphae, allantoid to cylindrical basidiospores usually less than 5 µm long, growing mostly on angiosperms and occasionally on gymnosperms, causing a white rot and having a distribution mainly in the subtropical and tropical forests of the world (Ryvarden 2004; Dai 2009, 2012; Hattori et al. 2012; Ryvarden et al. 2022; Wu et al. 2022; Zhao et al. 2024). As wood-inhabiting fungi, species of Nigroporus are saprophytes (Yuan et al. 2023), but they play a special role in forest ecosystems by decomposing wood and recycling organic matter (Hattori and Lee 2003; Wei and Dai 2004; Olou et al. 2023). Phylogenetic analysis demonstrated that Nigroporus belonged to the family Steccherinaceae in the Polyporales (Justo et al. 2017).

Previously, four species were accepted in the genus: Nigroporus macroporus Ryvarden & Iturr., N. stipitatus Douanla-Meli & Ryvarden, N. ussuriensis (Bondartsev & Ljub.) Y.C. Dai & Niemelä and N. vinosus (Dai and Niemelä 1995; Ryvarden and Iturriaga 2003; Douanla-Meli et al. 2007; Ryvarden et al. 2022). The molecular data of N. stipitatus and N. vinosus are available (Miettinen et al. 2012; Binder et al. 2013; Piepenbring et al. 2020). In addition, Ko and Jung (1999) mentioned that Trametes consors (Berk.) A. Mitra is more closely related to Nigroporus than Trametes.

Due to the lack of molecular data for N. macroporus and N. ussuriensis, the phylogenetic relationship among taxa of the genus was poorly known. During recent investigations on polypores in Asia and Oceania, more samples were collected and their morphology corresponds to the concept of N. vinosus. To confirm their identification, morphological examination and phylogenetic analyses based on the internal transcribed spacer (ITS), large subunit nuclear ribosomal RNA (nLSU) and translation elongation factor 1-alpha (TEF1) genes were carried out. Four new species are confirmed in our studied samples. All these four species are different from N. vinosus sensu stricto, and they are described as new species in this paper.

Materials and methods

Morphological studies

The studied specimens are deposited at the Fungarium of Beijing Forestry University (BJFC). Microscopic procedure followed Wu et al. (2022), and color terms followed Anonymous (1969) and Petersen (1996). Sections were studied at a magnification of up to 1000× using a Nikon E 80i microscope with phase-contrast illumination. Measurements and description of microscopic structures were made from slide preparations stained with Cotton Blue (CB) and Melzer’s reagent (IKI). Basidiospores were measured from sections cut from the tubes. To represent the variation in the size of the basidiospores, 5% of the measurements were excluded from each end of the range and are given in parentheses. Abbreviations used are as follows: KOH = 5% potassium hydroxide solution, IKI– = neither amyloid nor dextrinoid, CB– = acyanophilous, L = mean basidiospore length (arithmetic average of all basidiospores), W = mean spore width (arithmetic average of all basidiospores), Q = variation in the ratios of L/W between specimens studied, n = number of basidiospores measured from a given number of specimens.

DNA extraction, amplification, and sequencing

A Cetyltrimethylammonium Bromide (CTAB) new type plant DNA kit (Aidlab Biotechnologies Co., Ltd, Beijing, China) was used to obtain DNA from dried specimens, followed by the polymerase chain reaction (PCR) according to the manufacturer’s instructions with some modifications as described by Mao et al. (2023). Amplification of the ITS region used primer pairs ITS5 and ITS4 (White et al. 1990). Amplification of the nLSU regions used primer pairs LR0R and LR7 (Vilgalys and Hester 1990). Amplification of part of TEF1 used primer pairs EF1-983F and EF1-1567R (Rehner and Buckley 2005). The PCR cycling schedule for ITS was as follows: initial denaturation at 95 °C for 3 min, followed by 35 cycles at 94 °C for 40 s, 54 °C for 45 s, 72 °C for 1 min, and a final extension of 72 °C for 10 min. The PCR procedure for the nLSU was as follows: initial denaturation at 94 °C for 1 min, followed by 35 cycles at 94 °C for 30 s, 50 °C for 1 min, and 72 °C for 1.5 min, and a final extension of 72 °C for 10 min. The reaction procedure for the TEF1 is the same as the ITS, except that the annealing temperature is adjusted to 58 °C respectively (Mao et al. 2023). The purification and sequencing of the PCR products was conducted by the Beijing Genomics Institute (BGI), Beijing, China, with the same primers as used in PCR. The PCR amplified DNA products were stored in a refrigerator at minus 20 °C and newly generated sequences were deposited at GenBank (Tables 1, 2). Sequences generated from this study were aligned with additional sequences downloaded from GenBank using BioEdit (Hall 1999) and ClustalX (Thompson et al. 1997). In this study, a 2-gene dataset (ITS+nLSU) and 3-gene dataset (ITS+nLSU+TEF1) were used to reconstruct the phylogenetic position of the new species. All sequences of ITS, nLSU, TEF1 were respectively aligned in MAFFT 7 (https://mafft.cbrc.jp/alignment/server/; Katoh et al. 2019) and BioEdit. Alignments were spliced and exported to nexus and phylip in Mesquite (Maddison and Maddison 2021). The missing sequences and ambiguous nucleotides were coded as N.

Table 1.
Download as
CSV
XLSX

Information on the sequences used in this study. New sequences are in bold. * type specimen.

Species Sample number Location GenBank accession No
ITS nLSU
Antella americana KHL 11949 Sweden JN710509 JN710509
A. americana HHB-4100 USA KP135316 KP135196
A. chinensis Dai 8874 China JX110843 KC485541
A. chinensis Dai 9019 China JX110844 KC485542
A. niemelaei Renvall 3218 Finland AF126876 -
A. niemelaei Haikonen 14727 Finland AF126877 -
Antrodiella onychoides Miettinen 2312 Finland JN710517 JN710517
A. pallescens Nordén 8.8.2008 Sweden JN710518 JN710518
A. romellii Miettinen 7429 Finland JN710520 JN710520
A. semisupina Labrecque & Labbé 372 Canada JN710521 JN710521
A. stipitata FD-136 USA KP135314 KP135197
A. stipitata Yuan 5640 China KC485525 KC485544
Atraporiella neotropica Miettinen X1021 Belize HQ659221 HQ659221
A. yunnanensis CLZhao 604 China MF962482 MF962485
A. yunnanensis CLZhao 605 China MF962483 MF962486
Butyrea japonica MN 1065 Japan JN710556 JN710556
B. luteoalba FP-105786 USA KP135320 KP135226
B. luteoalba KHL 13238b Estonia JN710558 JN710558
Climacocystis borealis KHL 13318 Estonia JN710527 JN710527
Elaphroporia ailaoshanensis CLZhao 596 China MG231572 MG748855
E. ailaoshanensis CLZhao 597 China MG231847 MG748856
Etheirodon fimbriatum KHL 11905 Sweden JN710530 JN710530
E. fimbriatum HR 98811 Czech MT849300 -
E. purpureum MCW 642/18 Brazil MT849301 MT849301
Flaviporus brownii MCW 362/12 Brazil KY175008 KY175008
F. brownii X 462 Australia JN710538 JN710538
F. liebmannii X 249 China JN710539 JN710539
F. liebmannii Yuan 1766 China KC502914 -
F. subundatus MCW 367/12 Brazil KY175004 KY175004
F. subundatus MCW 457/13 Brazil KY175005 KY175005
F. tenuis MCW 442/13 Brazil KY175001 KY175001
F. tenuis MCW 356/12 Brazil KY175002 KY175002
Frantisekia fissiliformis CBS 435.72 USA MH860521 MH872232
F. mentschulensis BRNM 710170 Czech FJ496670 FJ496728
F. mentschulensis AH 1377 Austria JN710544 JN710544
F. ussurii Wei 3081 China KC485527 KC485545
F. ussurii Dai 8249 China KC485526 -
Junghuhnia crustacea X 262 Indonesia JN710553 JN710553
J. delicate MCW 564/17 Brazil MT849295 MT849295
J. delicate MCW 693/19 Brazil MT849297 MT849297
J. pseudocrustacea Yuan 6160 China MF139551 -
J. pseudocrustacea Zhou 283 China MF139552 -
Loweomyces fractipes X 1149 Slovakia JN710570 JN710570
L. fractipes MT 13/2012 Brazil KX378866 KX378866
L. spissus MCW 488/14 Brazil KX378869 KX378869
L. tomentosus MCW 366/12 Brazil KX378870 KX378870
L. wynneae X 1215 Denmark JN710604 JN710604
Metuloidea cinnamomea X 1228 Vietnam KU926963 -
M. fragrans LE 295277 Russia KC858281 -
M. murashkinskyi X 449 Russia JN710588 JN710588
M. reniformis MCW 542/17 Brazil MT849303 MT849303
M. reniformis MCW 523/17 Brazil MT849302 MT849302
M. rhinocephala X 460 Australia JN710562 JN710562
Mycorrhaphium hispidum MCW 363/12 Brazil MH475306 MH475306
M. hispidum MCW 429/13 Brazil MH475307 MH475307
M. subadustum Yuan 12976 China MW491378 MW488040
M. subadustum Dai 10173 China KC485537 KC485554
Nigroporus australianus Cui 16775* Australia PP622349 -
N. austroasianus Dai 18594 Malaysia PP622343 PP625976
N. austroasianus Dai 20632* China PP622344 PP669796
N. austroasianus Dai 28512 China PQ327581 PQ327583
N. vinosus BHS2008-100 USA JX109857 JX109857
N. vinosus 8182 USA JN710575 JN710575
N. vinosus Cui 7701 China PP622353 -
N. vinosus Cui 7854 China PP622352 -
N. vinosus Dai 16966 China PP692550 PP625980
N. vinosus Dai 26323 China PP622348 PP625978
N. vinosus Dai 26461 China PP622347 PP625979
N. vinosus Dai 28194 China PP955188 PP939654
N. vinosus KA17-0261 Korea MN294801 -
N. stipitatus X 546 Cameroon JN710574 JN710574
N. stipitatus KaiR 116 Benin MT110231 -
N. subvinosus Cui 17526 China PP622350
N. subvinosus Cui 18104 China PP622339 PP669797
N. subvinosus Dai 13136 China PP622342 -
N. subvinosus Cui 18097 China PP622345 -
N. subvinosus Dai 20445 China PP622340 PP625977
N. subvinosus Dai 25154 China PP622351
N. subvinosus Dai 26787* China PP622346 PP669794
N. subvinosus Dai 27441 China PP939653 PP955187
N. subvinosus LE-BIN 5057 Vietnam OR683766 -
N. yunnanensis Cui 18205 China PP622341 PP669795
N. yunnanensis Dai 19116* China PP622337 PP625974
N. yunnanensis Dai 19870 China PP622338 PP625975
N. yunnanensis CLZhao 4067 China OR167780 -
N. yunnanensis CLZhao 4767 China OR167781 -
Steccherinum bourdotii HR99893 Czech MT849311 -
S. bourdotii Saarenoksa 10195 Finland JN710584 JN710584
S. hirsutum CLZhao 4222 China MW290040 MW290054
S. hirsutum CLZhao 4523 China MW290041 MW290055
S. ochraceum KHL11902 Sweden JN710590 JN710590
S. ochraceum 2060 Sweden JN710589 JN710589
S. subtropicum CLZhao 16901 China OP799391 -
S. subtropicum CLZhao 11059 China OP799390 OP799377
Trullella conifericola Cui 2851 China MT269764 -
T. conifericola Yuan 12655 Vietnam MT269760 MT259326
T. conifericola Yuan 12657 Vietnam MT269761 MT259327
T. dentipora X 200 Venezuela JN710512 JN710512
T. duracina MCW 410/13 Brazil MH475309 MH475309
T. duracina RP 96 Brazil MH475310 MH475310
T. duracina Dai 20474 China OL437266 OL434415
Xanthoporus syringae Jeppson 2264 Sweden JN710607 JN710607
X. syringae AFTOL-ID 774 China AY789078 AY684166
Table 2.
Download as
CSV
XLSX

Information on the sequences of TEF1 used in this study. New sequences are in bold. * type specimen.

Species Specimen number GenBank accession numbers
TEF1
Nigroporus australianus Cui 16775* PP719863
N. austroasianus Dai 18594 PP719857
N. austroasianus Dai 20632* PP719858
N. austroasianus Dai 28512 PQ540992
N. subvinosus Cui 18104 PP706386
N. subvinosus Dai 13136 PP719856
N. subvinosus Dai 26787* PP719859
N. vinosus 8182 JN710728
N. vinosus Cui 7584 PP719855
N. vinosus Dai 16966 PP719862
N. vinosus Dai 26323 PP719861
N. vinosus Dai 26461 PP719860
N. vinosus Dai 28194 PP975431
N. yunnanensis Cui 18205 PP719855

Phylogenetic analyses

In the study, a sequence of Climacocystis borealis (Fr.) Kotl. & Pouzar obtained from GenBank was used as an outgroup to root trees in the ITS+nLSU analysis of Steccherinaceae. Sequences of Trullella duracina (Pat.) Zmitr. and Trullella conifericola T. Cao & H.S. were used as the outgroups to root trees in the ITS+nLSU+TEF1 analysis (Miettinen et al. 2012; Dong et al. 2023). Alignment datasets were deposited in TreeBase (submission ID 31362, 31363; http://www.treebase.org). Maximum Likelihood (ML) and Bayesian Inference (BI) analyses were conducted based on these datasets following previous studies (Liu and Dai 2021; Dong et al. 2023). The best-fit evolutionary model for each gene fragment (ITS, nLSU, and TEF1) was selected individually by Hierarchical Likelihood Ratio Tests (HLRT) in MrModeltest 2.2 (Nylander 2004) after scoring 24 models of evolution for each fragment in PAUP* version 4.0b10 (Swofford 2002).

Sequences were analyzed using Maximum Likelihood (ML) with raxmIHPC-PTHREADS-SSE3 through raxmlGUI 2.0.0. (Edler et al. 2021). Branch support (BS) for Maximum Likelihood (ML) is the supporting values of each node obtained by running 1000 bootstrap replicates under the GTRGAMMA model. Bayesian Posterior Probabilities (BPP) were computed with MrBayes 3.1.2 (Ronquist and Huelsenbeck 2003; Nylander 2004). Four Markov chains were run for 2 M generations (2-gene dataset), and for 1.2 M generations (3-gene dataset) until the split deviation frequency value was less than 0.01, and trees were sampled every 100 generations. The first 25% of the sampled trees were discarded as burn-in and the remaining ones were used to reconstruct a majority rule consensus and calculate Bayesian Posterior Probabilities (BPP) of the clades. For each dataset, partitions were manually defined for each gene region based on trimmed segment lengths, and the best model was selected for each gene segment. All trees were viewed in FIGTREE v. 1.4.3 (http://tree.bio.ed.ac.uk/software/figtree/). Branches that received bootstrap support (ML ≥ 50%, BPP ≥ 0.90) were considered as significantly supported. The ML bootstrap supports ≥ 50% and BPP ≥ 0.75 are presented on topologies from ML analyses, respectively.

Results

Phylogenetic analyses

The combined 2-gene dataset (ITS+nLSU) included sequences from 85 samples representing 51 species. The dataset had an aligned length of 2265 characters, of which 1468 (65%) characters were constant, 173 (8%) were variable and parsimony-uninformative and 624 (27%) were parsimony informative. The phylogenetic reconstruction performed with ML and BI analyses for two combined datasets showed similar topology and few differences in statistical support. The best model-fit applied in the Bayesian analysis was GTR+I+G for both ITS+nLSU, lset nst = 6, rates = invgamma, and prset statefreqpr = dirichlet (1, 1, 1, 1). Bayesian analysis resulted in a nearly congruent topology with an average standard deviation of split frequencies = 0.009757 to ML analysis, and thus only the ML tree is provided (Fig. 1).

Figure 1. 

Maximum Likelihood strict consensus tree illustrating the phylogeny of four new species and related species in the family Steccherinaceae based on ITS+nLSU sequences. Branches are labeled with Maximum Likelihood bootstrap values higher than 50% and Bayesian Posterior Probabilities more than 0.75.

The phylogeny inferred from the ITS+nLSU sequences demonstrated that sixteen genera nested in the family Steccherinaceae and newly examined seven samples formed four distinct clades at the species level, nested in the Nigroporus clade (Marked as Lineage I–IV, Lineage I with 57% ML-BS, 0.97 BPP; Lineage II with 79% ML-BS, 1.00 BPP; Lineage III with 82% ML-BS, 1.00 BPP; Clade IV with 99% ML-BS, 1.00 BPP; Fig. 1).

The combined 3-gene dataset (ITS+nLSU+TEF1) included sequences from 31 samples representing eight species. The dataset had an aligned length of 2572 characters, of which 2317 (90%) characters were constant, 80 (3%) were variable and parsimony-uninformative and 175 (7%) were parsimony informative. The phylogenetic reconstruction performed with ML and BI analyses for two combined datasets showed similar topology and few differences in statistical support. The best model-fit applied in the Bayesian analysis were HKY+G for ITS (lset nst = 2, rates = gamma, and prset statefreqpr = dirichlet (1, 1, 1, 1)), GTR+G for nLSU (lset nst = 6, rates = gamma, and prset statefreqpr = dirichlet (1, 1, 1, 1)), SYM for TEF1 (lset nst = 6 and prset statefreqpr = dirichlet (1, 1, 1, 1)). Bayesian analysis resulted in a nearly congruent topology with an average standard deviation of split frequencies = 0.009991 (BI), and thus only the ML tree is provided (Fig. 2). The phylogeny inferred from ITS+nLSU+TEF1 sequences demonstrated that Lineage I formed a monophyletic lineage, Lineage II was sister to Lineage IV, and Lineage III was sister to Lineage II and Lineage IV (Fig. 2).

Figure 2. 

Maximum Likelihood analysis of Nigroporus based on a dataset of ITS+nLSU +TEF1. ML bootstrap values higher than 50% and Bayesian Posterior Probabilities values more than 0.75 are shown. New taxa are in bold.

Taxonomy

Nigroporus australianus Y.C. Dai, X.L. Li & Yuan Yuan, sp. nov.

MycoBank No: 853914
Figs 3, 4

Holotype

Australia • Queensland, Cairns, Crater Lakes National Park, on fallen angiosperm trunk, 17 May 2018, Cui 16775 (BJFC 030074).

Etymology

Australianus (Lat.): refers to the species being found in Australia.

Description

Basidiomata. Annual, pileate, solitary to imbricate, leathery and without odor or taste when fresh, becoming woody hard and light in weight upon drying; pilei semicircular to flabelliform, projecting up to 3.4 cm, 7.2 cm wide and 3.5 mm thick at base. Pileal surface bay to purplish chestnut when fresh, becoming grayish brown to fuscous upon drying, concentrically zonate, glabrous, margin thin. Pore surface vinaceous when drying; sterile margin indistinct; pores round to angular, 9–10 per mm; dissepiments thin, lacerate. Context fawn, corky when dry, up to 0.5 mm thick. Tubes chestnut, corky when dry, up to 3 mm long.

Figure 3. 

A basidioma of Nigroporus australianus (holotype, Cui 16775). Scale bar: 1 cm.

Hyphal structure. Hyphal system dimitic; generative hyphae bearing clamp connections; skeletal hyphae IKI–, CB–; tissues darkening in KOH.

Context. Generative hyphae hyaline, thin- to slightly thick-walled, occasionally branched, 3.2–6.4 µm in diam.; skeletal hyphae yellowish brown, thick-walled with a wide to narrow lumen, unbranched, slightly flexuous, interwoven, 3.2–5.4 µm in diam.

Figure 4. 

Microscopic structures of Nigroporus australianus (holotype, Cui 16775) a basidiospores b basidia c basidioles d cystidioles e hyphae from context f hyphae from trama.

Tubes. Generative hyphae hyaline, thin-walled, occasionally branched, 2.8–5.0 µm in diam.; skeletal hyphae dominant, yellowish brown, thick-walled with a narrow lumen, unbranched, slightly flexuous, interwoven, 2.8–3.8 µm in diam. Cystidia absent; cystidioles frequent, fusoid, hyaline, thin-walled, smooth, 7–9.7 × 3.2–3.8 µm. Basidia barrel-shaped, with four sterigmata and a basal clamp connection, 8.9–11 × 4.1–4.6 µm. basidioles of similar shape to basidia, but smaller.

Spores. Basidiospores allantoid, hyaline, thin-walled, smooth, IKI–, CB–, (3.2–)3.4–4.1(–4.2) × (1.2–)1.3–1.5 µm, L = 3.62 µm, W = 1.4 µm, Q = 2.59 (n = 30/1).

Nigroporus austroasianus Y.C. Dai, X.L. Li & Yuan Yuan, sp. nov.

MycoBank No: 853915
Figs 5, 6

Holotype

China • Yunnan Province, Mengla County, Shangyong Nature Reserve, on rotten angiosperm wood, 20 August 2019, Dai 20632 (BJFC 032299).

Etymology

Austroasianus (Lat.): refers to the distribution of the species in South Asia.

Description

Basidiomata . Annual, pileate, a few imbricate, leathery and without odor or taste when fresh, becoming corky and light in weight upon drying. Pilei semicircular to spathulate, projecting up to 4 cm, 6 cm wide and 1.4 mm thick at center. Pileal surface grayish violet to dark violet when fresh, becoming grayish brown upon drying; margin thin and sharp, usually lobed. Pore surface flesh pink to lavender when fresh, becoming fawn when bruised, pale mouse gray when dry, sterile margin distinct, cream when dry, up to 1.1 mm wide; pores round to angular, 10–13 per mm; dissepiments thin, entire to lacerate. Context vinaceous to reddish brown, corky when dry, up to 0.4 mm thick. Tubes concolorous with pore surface, corky when dry, up to 1 mm long.

Figure 5. 

Basidiomata of Nigroporus austroasianus (holotype, Dai 20632). Scale bar: 1 cm.

Hyphal structure. Hyphal system dimitic; generative hyphae bearing clamp connections; skeletal hyphae IKI–, CB–; tissues darkening in KOH.

Context. Generative hyphae frequent, hyaline to pale yellow, thin- to slightly thick-walled, occasionally branched, 2–4 µm in diam.; skeletal hyphae dominant, pale yellow, thick-walled with a wide lumen, unbranched, slightly flexuous, interwoven, 2.5–4 µm in diam.

Figure 6. 

Microscopic structures of Nigroporus austroasianus (holotype, Dai 20632) a basidiospores b basidia c basidioles d hyphae from context e hyphae from trama.

Tubes. Generative hyphae dominant, hyaline, thin-walled, occasionally branched, 2.5–4.5 µm in diam.; skeletal hyphae pale yellow, slightly thick-walled with a wide lumen, unbranched, slightly flexuous, interwoven, 3.5–6.5 µm in diam. Cystidia and cystidioles absent. Basidia pyriform to barrel-shaped, with four sterigmata and a basal clamp connection, 7–12 × 3.5–4.5 µm. Basidioles barrel-shaped, smaller than basidia.

Spores. Basidiospores allantoid, hyaline, thin-walled, smooth, occasionally with one or two small guttules. IKI–, CB–, (2.1–)3–4.1(–4.2) × (1.1–)1.5–2(–2.2) µm, L = 3.21 µm, W = 1.63 µm, Q = 1.83–2.01 (n = 90/3).

Additional specimen examined

(paratype). China • Guangxi Zhuang Autonomous Region, Leye County, Yachang Orchid Nature Reserve, stump of Pinus yunnanensis, 29 June 2024, Dai 28512 (BJFC048771). Malaysia • Selangor, Kota, Damansara, Community Forest Reserve, on rotten angiosperm wood, 16 April 2018, Dai 18594 (BJFC 026882).

Nigroporus subvinosus Y.C. Dai, X.L. Li & Yuan Yuan, sp. nov.

MycoBank No: 853916
Figs 7, 8

Holotype

China • Xizang Autonomous Region, Linzhi, Motuo County, on rotten angiosperm wood, 24 October 2023, Dai 26787 (BJFC 044337).

Etymology

Subvinosus (Lat.): refers to the species resembling Nigroporus vinosus.

Description

Basidiomata. Annual, pileate, usually solitary, leathery and without odor or taste when fresh, becoming woody hard and light in weight upon drying; pilei semicircular to flabelliform, projecting up to 3.9 cm, 3.7 cm wide and 3 mm thick at base. Pileal surface dark grayish blue, vinaceous gray to black when fresh, become umber to fawn upon drying, concentrically zonate, glabrous, margin thin, cream. Pore surface flesh pink to brownish vinaceous when fresh, becoming fawn when bruised, reddish brown when dry; sterile margin distinct, white when dry, up to 2.3 mm wide; pores round to angular, 9–11 per mm; dissepiments thin, entire to lacerate. Context fawn to reddish brown, corky when dry, up to 1.7 mm thick. Tubes concolorous with pore surface, corky when dry, up to 1.3 mm long.

Figure 7. 

Basidiomata of Nigroporus subvinosus (holotype, Dai 26787). Scale bars: 1 cm (a, b).

Hyphal structure. Hyphal system dimitic; generative hyphae bearing clamp connections; skeletal hyphae IKI–, CB–; tissues darkening in KOH.

Context. Generative hyphae hyaline, thin- to slightly thick-walled, occasionally branched, 3–4.4 µm in diam.; skeletal hyphae dominant, yellowish brown, thick-walled with a narrow lumen to subsolid, unbranched, slightly flexuous, interwoven, 3.3–4.5 µm in diam.

Figure 8. 

Microscopic structures of Nigroporus subvinosus (holotype, Dai 26787) a basidiospores b basidia c basidioles d cystidioles e hyphae from context f hyphae from trama.

Tubes. Generative hyphae hyaline, thin- to slightly thick-walled, occasionally branched, 2.6–4.4 µm in diam.; skeletal hyphae dominant, yellowish brown, thick-walled with a narrow lumen to subsolid, unbranched, slightly flexuous, interwoven, 2.4–5 µm in diam. Cystidia absent; cystidioles frequent, fusoid, hyaline, thin-walled, smooth, 10–18 × 3–5 µm. Basidia barrel-shaped, with four sterigmata and a basal clamp connection, 6–10 × 3–4 µm. Basidioles of similar shape to basidia, but smaller.

Spores. Basidiospores allantoid, hyaline, thin-walled, smooth, usually with one or two guttules, IKI–, CB–, (2.9–)3–4.5(–5) × (1.4–)1.5–2.1(–2.3) µm, L = 3.7 µm, W = 1.78 µm, Q = 2.04–2.09 (n = 240/8).

Additional specimens examined

(paratypes). China • Guangxi Zhuang Autonomous Region, Shangsi County, Natura Subsidium magnum montem National, on dead angiosperm tree, 26 May 2024, Dai 27441 (BJFC047701). • Hainan Province, Baisha Li Autonomous County, Qingsong, on rotten wood of Pinus latteri, 10 June 2023, Dai 25154 (BJFC 042706). • Sichuan Province, Yanyuan County, on stump of Pinus yunnanensis, 15 August 2019, Cui 17526 (BJFC 034385). • Yunnan Province, Baoshan City, Gaoligongshan Nature Reserve, on angiosperm stump, 7 November 2019, Cui 18097 (BJFC 034956), Cui 18104 (BJFC 034963). • Puer, Puer Forest Park, Xiniuping Scenic Spot, on rotten angiosperm wood, 17 August 2019, Dai 20445 (BJFC 032113). • Yingjiang County, Tongbiguan Nature Reserve, on angiosperm stump, 30 October 2012, Dai 13136 (BJFC 013353).

Nigroporus yunnanensis Y.C. Dai, X.L. Li & Yuan Yuan, sp. nov.

MycoBank No: 853917
Figs 9, 10

Holotype

China • Yunnan Province: Baoshan County, Baihualing Forest Park, on fallen angiosperm trunk, 21 September 2018, Dai 19116 (BJFC 027585).

Etymology

Yunnanensis (Lat.): refers to the species being found in Yunnan Province, southwest China.

Description

Basidiomata. Annual, effused-reflexed to pileate, leathery and without odor or taste when fresh, becoming woody hard upon drying, up to 8.5 cm long, 4 cm wide when resupinate; pilei semicircular, projecting up to 1 cm, 1.5 cm wide and 2.5 mm thick at base. Pileal surface brown when fresh, becoming liver brown to dark brown upon drying, concentrically zonate, glabrous, margin thin. Pore surface vinaceous to brownish vinaceous when fresh, become purplish date when bruised, russet when dry; sterile margin distinct, white when fresh, and cream when dry, up to 0.5 mm wide; pores round to angular, 7–10 per mm; dissepiments thin, lacerate. Context liver brown, hard corky when dry, up to 1.5 mm thick. Tubes concolorous with pore surface, corky when dry, up to 1 mm long.

Figure 9. 

Basidiomata of Nigroporus yunnanensis (holotype, Dai 19116). Scale bar: 1 cm.

Hyphal structure. Hyphal system dimitic; generative hyphae bearing clamp connections; skeletal hyphae IKI–, CB–; tissues darkening in KOH.

Context. Generative hyphae hyaline, thin-walled, occasionally branched, 1.5–4 µm in diam.; skeletal hyphae dominant, yellowish brown, slightly thick-walled with a wide lumen, unbranched, slightly flexuous, interwoven, 3–4.5 µm in diam.

Figure 10. 

Microscopic structures of Nigroporus yunnanensis (holotype, Dai 19116) a basidiospores b basidia c basidioles d cystidioles e hyphae from context f hyphae from trama.

Tubes. Generative hyphae hyaline, thin- to slightly thick-walled, occasionally branched, 2.5–4.5 µm in diam.; skeletal hyphae dominant, yellowish brown, thick-walled with a wide to narrow lumen, unbranched, slightly flexuous, interwoven, 4–5 µm in diam. Cystidia absent; cystidioles present, fusoid, hyaline, thin-walled, smooth, 7.5–11 × 2.5–4 µm. Basidia barrel-shaped, with four sterigmata and a basal clamp connection, 5–7.5 × 3–4.5 µm; basidioles of similar shape to basidia, but smaller.

Spores. Basidiospores allantoid, hyaline, thin-walled, smooth, occasionally with one or two guttules. IKI–, CB–, (3.8–)4–4.5(–5) × (1.8–)1.9–2.2(–2.5) µm, L = 4.19 µm, W = 2.03 µm, Q = 2.06–2.09 (n = 90/3).

Additional specimens examined

(paratypes). China • Yunnan Province, Pingbian County, Daweishan National Forest Park, on fallen angiosperm branch, 27 June 2019, Dai 19870 (BJFC 031544). • Tengchong County, Gaoligongshan, Dahaoping, on dead angiosperm tree, 10 November 2019, Cui 18205 (BJFC 035064).

Discussion

In the present study, phylogenetic analyses on the Steccherinaceae using a 2-gene sequence dataset (Fig. 1) and on Nigroporus using a 3-gene sequence dataset (Fig. 2) were carried out. Nigroporus is monophyletic and closely related to Trullella Zmitr. However, Trullella has more or less cream-colored basidiomata, a monomitic hyphal structure in context, hyaline and cyanophilous skeletal hyphae, and leptocystidia (Zmitrovich 2018), while Nigroporus has pinkish to bluish gray basidiomata, a dimitic hyphal system in context, fuliginous and acyanophilous skeletal hyphae, and the absence of leptocystidia.

Phylogenetically, Nigroporus australianus, N. austroasianus, N. subvinosus and N. yunnanensis are closely related to N. vinosus (Figs 1, 2), and have more or less similar macromorphology, that is why the four new species were treated as the N. vinosus. However, the nucleotide differences in the ITS regions among these species are more than 2.5%. Morphologically, N. australianus is different from N. austroasianus, N. subvinosus, N. vinosus and N. yunnanensis by its indistinct sterile margin and narrower basidiospores (1.3–1.5 µm, Q = 2.59 vs. 1.5–2.2 µm, Q = 1.83–2.09). N. austroasianus differs from N. subvinosus, N. vinosus and N. yunnanensis by smaller pores (10–13 per mm vs. 7–11 per mm), generative hyphae dominant in tube trama, and lacking cystidioles, while skeletal hyphae are dominant in tube trama and cystidioles are present in the latter three species. Nigroporus subvinosus is distinguished from N. vinosus by basidiospores with guttules and subsolid skeletal hyphae. Nigroporus subvinosus differs from N. yunnanensis by thicker basidiomata (> 3 mm vs. < 2.5 mm). Nigroporus yunnanensis is different from N. vinosus by shorter cystidioles (7.5–11 µm vs. 12–18 µm). Among the existing species of Nigroporus without DNA available, the four new species are readily distinguished from N. stipitatus by having pileate basidiomata (Douanla-Meli et al. 2007), and they are different from N. macroporus and N. ussuriensis by having smaller pores (7–13 per mm vs. 1–2 per mm in N. macroporus vs. 5–7 per mm in N. ussuriensis, Ryvarden and Iturriaga 2003). Furthermore, basidiospores of our new species are allantoid without tapering apex, while the basidiospores of N. ussuriensis are cylindric with a distinctly tapering apex (Dai and Niemelä 1995). Despite the phylogenetic results showing a distinct genetic distance between the Malaysian material (Dai 18594) and the Chinese materials (Dai 20632 and Dai 28512, Figs 1, 2), the three specimens have very similar morphology, and they represent a single species, N. austroasianus.

Polyporus tristis Lév. was described from Indonesia by Léveillé (1846), and it was considered a synonym of Nigroporus vinosus. Our new species N. austroasianus is derived from N. vinosus, and was found in Malaysia and tropical to subtropical China (South Asia). Both names may represent a single species, but Polyporus tristis is nomenclature illegitimate because Polyporus tristis Pers. 1825 (=Trametes tristis (Pers.) Roum.) had priority. So, we describe the tropical Asia taxon as N. austroasianus.

Key to accepted species of Nigroporus

1 Basidiomata stipitate N. stipitatus
– Basidiomata pileate to resupinate 2
2 Pores 1–2 per mm; South American species N. macroporus
– Pores > 3 per mm; pantropical species 3
3 Cystidioles absent 4
– Cystidioles presence 5
4 Pores 5–7 per mm N. ussuriensis
– Pores 10–13 per mm N. austroasianus
5 Pilei < 2.5 mm thick at base N. yunnanensis
– Pilei > 2.5 mm thick at base 6
6 Basidiospores < 1.5 µm wide N. australianus
– Basidiospores > 1.5 µm wide 7
7 Basidiospores with one or two guttules and skeletal hyphae subsolid N. subvinosus
– Basidiospores without guttule and skeletal hyphae with a wide lumen N. vinosus

Acknowledgments

We thank Dr. Genevieve Gates (Tasmania, Australia) for improving the manuscript.

Additional information

Conflict of interest

The authors have declared that no competing interests exist.

Ethical statement

No ethical statement was reported.

Funding

The research is supported by the National Natural Science Foundation of China (Project Nos. U23A20142, 32161143013, 32370013), the Yunnan Province expert workstation program (No. 202205AF150014), and the Postdoctoral Fellowship Program (Grade C) of China Postdoctoral Science Foundation (GZC20230254).

Author contributions

Conceptualization: XLL, YCD. Data curation: ZBL, YCD, XLL. Formal analysis: YCD, XLL. Funding acquisition: YCD. Investigation: YCD, YHJ, XLL. Methodology: YCD, ZBL, XLL. Project administration: YCD, YY, HGL. Resources: ZBL, XLL, YCD. Software: XLL, YCD. Supervision: YCD. Validation: YCD, XLL. Visualization: YCD, XLL. Writing - original draft: XLL. Writing - review and editing: YCD, YY.

Author ORCIDs

Xiang-Lin Li https://orcid.org/0009-0007-4364-6994

Yu-Cheng Dai https://orcid.org/0000-0002-6523-0320

Zhan-Bo Liu https://orcid.org/0000-0002-3894-5398

Hong-Gao Liu https://orcid.org/0000-0002-9508-3245

Yuan Yuan https://orcid.org/0000-0001-6674-9848

Data availability

All of the data that support the findings of this study are available in the main text.

References

  • Anonymous (1969) Flora of British fungi: Color identification chart. Her Majesty’s Stationery Office, London, 1–6.
  • Binder M, Justo A, Riley R, Salamov A, Lopez-Giraldez F, Sjökvist E, Copeland A, Foster B, Sun H, Larsson E, Larsson KH, Townsend J, Grigoriev IV, Hibbett DS (2013) Phylogenetic and phylogenomic overview of the Polyporales. Mycologia 105(6): 1350–1373. https://doi.org/10.3852/13-003
  • Dai YC (2009) Illustrations of wood-decaying fungi on stored wood or structural timber in China. Science Press, Beijing, 1–144.
  • Dai YC, Niemelä T (1995) Changbai wood-rotting fungi 4. Some species described by A. S. Bondartsev and L. V. Lyubarsky from the Russian Far East. Annales Botanici Fennici 32: 211–226.
  • Dong JH, Zhang XC, Chen JJ, Zhu ZL, Zhao CL (2023) A phylogenetic and taxonomic study on Steccherinum (Polyporales, Basidiomycota): Focusing on three new Steccherinum species from southern China. Frontiers in Cellular and Infection Microbiology 12: 1103579. https://doi.org/10.3389/fcimb.2022.1103579
  • Edler D, Klein J, Antonelli A, Silvestro D (2021) raxmlGUI 2.0: A graphical interface and toolkit for phylogenetic analyses using RAxML. Methods in Ecology and Evolution 12(2): 373–377. https://doi.org/10.1111/2041-210X.13512
  • Hall TA (1999) BioEdit: A user-friendly biological sequence alignment editor and analysis program for Windows 95/98/NT. Nucleic Acids Symposium Series 41: 95–98.
  • Hattori T, Yamashita S, Lee SS (2012) Diversity and conservation of wood-inhabiting polypores and other aphyllophoraceous fungi in Malaysia. Biodiversity and Conservation 21(9): 2375–2396. https://doi.org/10.1007/s10531-012-0238-x
  • Justo A, Miettinen O, Floudas D, Ortiz-Santana B, Sjökvist E, Lindner D, Nakasone K, Niemelä T, Larsson KH, Ryvarden L, Hibbett DS (2017) A revised family-level classification of the Polyporales (Basidiomycota). Fungal Biology 121(9): 798–824. https://doi.org/10.1016/j.funbio.2017.05.010
  • Katoh K, Rozewicki J, Yamada KD (2019) MAFFT online service: Multiple sequence alignment, interactive sequence choice and visualization. Briefings in Bioinformatics 20(4): 1160–1166. https://doi.org/10.1093/bib/bbx108
  • Léveillé JH (1846) Descriptions des champignons de l’herbier du Muséum de Paris. Annales des Sciences Naturelles 5: 249–305.
  • Liu ZB, Dai YC (2021) Steccherinum fragile sp. nov. and S. subcollabens comb. nov. (Steccherinaceae, Polyporales), evidenced by morphological characters and phylogenetic analysis. Phytotaxa 483(2): 106–116. https://doi.org/10.11646/phytotaxa.483.2.3
  • Miettinen O, Larsson E, Sjökvist E, Larsson KH (2012) Comprehensive taxon sampling reveals unaccounted diversity and morphological plasticity in a group of dimitic polypores (Polyporales, Basidiomycota). Cladistics 1(3): 1–20. https://doi.org/10.1111/j.1096-0031.2011.00380.x
  • Murrill WA (1905) The Polyporaceae of North America 11. A synopsis of the brown pileate species. Bulletin of the Torrey Botanical Club 32(7): 353–371. https://doi.org/10.2307/2478499
  • Olou BA, Langer E, Ryvarden L, Krah FS, Hounwanou GB, Piepenbring M, Yorou NS (2023) New records and barcode sequence data of wood-inhabiting polypores in Benin with notes on their phylogenetic placements and distribution. Fungal Systematics and Evolution 11(1): 11–42. https://doi.org/10.3114/fuse.2023.11.02
  • Petersen JH (1996) The Danish mycological society’s colour-chart. Foreningen til Svampekundskabens Fremme, Greve, 1–6.
  • Piepenbring M, Maciá-Vicente JG, Codjia JEI, Glatthorn C, Kirk P, Meswaet Y, Minter D, Olou BA, Reschke K, Schmidt M, Yorou NS (2020) Mapping mycological ignorance-checklists and diversity patterns of fungi known for West Africa. IMA Fungus 11(1): 13. https://doi.org/10.1186/s43008-020-00034-y
  • Rehner SA, Buckley E (2005) A Beauveria phylogeny inferred from nuclear ITS and EF1-α sequences: Evidence for cryptic diversification and links to Cordyceps teleomorphs. Mycologia 97(1): 84–98. https://doi.org/10.3852/mycologia.97.1.84
  • Ryvarden L (2004) Neotropical polypores 2. Polyporaceae. Abortiporus-Meripilus. Synopsis Fungorum 34: 1–443.
  • Ryvarden L, Decock C, Mossebo D, Masuka A (2022) Poroid fungi of Africa. Synopsis Fungorum 45: 1–271.
  • Thompson JD, Gibson TJ, Plewniak F, Jeanmougin F, Higgins DG (1997) The Clustal X windows interface: Flexible strategies for multiple sequence alignment aided by quality analysis tools. Nucleic Acids Research 25(24): 4876–4882. https://doi.org/10.1093/nar/25.24.4876
  • Vilgalys R, Hester M (1990) Rapid genetic identification and mapping of enzymatically amplified ribosomal DNA from several Cryptococcus species. Journal of Bacteriology 172(8): 4238–4246. https://doi.org/10.1128/jb.172.8.4238-4246.1990
  • Wei YL, Dai YC (2004) The ecological function of wood-inhabiting fungi in forest ecosystem. Chinese Journal of Applied Ecology 15: 1935–1938.
  • White TJ, Bruns T, Lee S, Taylor J (1990) Amplification and direct sequencing of fungal ribosomal RNA genes for phylogenetics. PCR Protocols: A Guide to Methods and Applications. Academic Press, New York, 315–322. https://doi.org/10.1016/B978-0 12-372180-8.50042-1
  • Yuan Y, Bian LS, Wu YD, Chen JJ, Wu F, Liu HG, Zeng GY, Dai YC (2023) Species diversity of pathogenic wood-rotting fungi (Agaricomycetes, Basidiomycota) in China. Mycology 14(3): 204–226. https://doi.org/10.1080/21501203.2023.2238779
  • Zhao H, Wu YD, Yang ZR, Liu HG, Wu F, Dai YC, Yuan Y (2024) Polypore and a comparison with temperate and boreal regions of the Northern Hemisphere. Forest Ecosystems 11: 100200. https://doi.org/10.1016/j.fecs.2024.100200
  • Zmitrovich IV (2018) Conspectus systematis Polyporacearum v. 1.0. Folia Cryptogamica Petropolitana 6: 3–145.

Xiang-Lin Li and Yu-Cheng Dai contributed equally to this work.
login to comment