Front. Microbiol. Frontiers in Microbiology Front. Microbiol. 1664-302X Frontiers Media S.A. 10.3389/fmicb.2021.661281 Microbiology Original Research Additions to the Genus Arthrinium (Apiosporaceae) From Bamboos in China Feng Yao 1 2 Liu Jian-Kui (Jack) 3 * Lin Chuan-Gen 4 Chen Ya-Ya 2 5 Xiang Mei-Mei 6 Liu Zuo-Yi 2 * 1College of Agriculture, Guizhou University, Guiyang, China 2Guizhou Key Laboratory of Agricultural Biotechnology, Guizhou Academy of Agricultural Sciences, Guiyang, China 3School of Life Sciences and Technology, University of Electronic Science and Technology, Chengdu, China 4Centre of Excellence in Fungal Research, Mae Fah Luang University, Chiang Rai, Thailand 5Institute of Crop Germplasm Resources, Guizhou Academy of Agricultural Sciences, Guiyang, China 6Innovative Institute for Plant Health, Zhongkai University of Agriculture and Engineering, Guangzhou, China

Edited by: Peter Edward Mortimer, Kunming Institute of Botany, Chinese Academy of Sciences, China

Reviewed by: Indunil Senanayake, Shenzhen University, China; ZongLong Luo, Dali University, China

 *Correspondence: Jian-Kui (Jack) Liu, liujiankui@uestc.edu.cn Zuo-Yi Liu, gzliuzuoyi@163.com

This article was submitted to Evolutionary and Genomic Microbiology, a section of the journal Frontiers in Microbiology

 07 04 2021 2021 12 661281 30 01 2021 10 03 2021 Copyright © 2021 Feng, Liu, Lin, Chen, Xiang and Liu. 2021 Feng, Liu, Lin, Chen, Xiang and Liu

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Arthrinium has a widespread distribution occurring in various substrates (e.g., air, soil debris, plants, lichens, marine algae and even human tissues). It is characterized by the basauxic conidiogenesis in the asexual morph, with apiospores in the sexual morph. In this study, seventeen isolates of Arthrinium were collected in China. Based on their morphology and phylogenetic characterization, four new species (A. biseriale, A. cyclobalanopsidis, A. gelatinosum, and A. septatum) are described and seven known species (A. arundinis, A. garethjonesii, A. guizhouense, A. hydei, A. neosubglobosa, A. phyllostachium and A. psedoparenchymaticum) are identified, of which the sexual morph of three species (A. guizhouense, A. phyllostachium and A. psedoparenchymaticum) and asexual morph of A. garethjonesii are reported for the first time. The detailed descriptions, illustrations and comparisons with related taxa of these new collections are provided. Phylogenetic analyses of combined ITS, LSU, TUB2, and TEF sequence data support their placements in the genus Arthrinium and justify the new species establishments and identifications of known species.

 4 new taxa asexual-sexual morphs multi-genes phylogeny taxonomy Introduction

The genus Arthrinium Kunze belongs to the family Apiosporaceae, which was introduced by Hyde et al. (1998) and typified by the genus Apiospora (Ellis, 1971; Seifert et al., 2011; Hyde et al., 2020). Arthrinium is the largest genus within Apiosporaceae and it has a widespread distribution on variety of hosts, 77 species have been recorded by Species Fungrom (March, 2021). Classification of Arthrinium was primarily based on conidial shape, conidiophores, sterile cells, and the presence of setae. Some morphologically different taxa (genera) grouped with Arthrinium when use the molecular data (Crous and Groenewald, 2013). Thus, those characteristics could be not fully inferred about the phylogenetic relationships for Arthrinium (Crous and Groenewald, 2013; Wang et al., 2018; Pintos et al., 2019). Except for being reported as saprobes (Agut and Calvo, 2004; Crous and Groenewald, 2013; Dai et al., 2016, 2017; Jiang et al., 2018; Wang et al., 2018; Jiang et al., 2019, 2020; Luo et al., 2019; Pintos et al., 2019; Yan et al., 2019; Mapook et al., 2020; Senanayake et al., 2020a; Tang et al., 2020), the species of Arthrinium also includes phytopathogenic fungi, for instance, A. arundinis causing brown culm streak of Phyllostachys praecox, A. phaeospermum causing culm rot on Phyllostachys viridis and cutaneous infections of humans (Rai, 1989; Zhao et al., 1990; Martínez-Cano et al., 1992; Mavragani et al., 2007; Crous and Groenewald, 2013; Li et al., 2016; Wang et al., 2018).

we are carrying out the survey of fungal diversity in Karst formations of the Asian region, and many new taxa are described in last few years (Li et al., 2016; Chen et al., 2017, 2020; Zhang et al., 2017, 2019; Feng et al., 2019; Liu et al., 2019; Dissanayake et al., 2020b). In this study, seventeen Arthrinium-like were collected in Guizhou and Guangdong province, China and can be recognized as eleven Arthrinium species based on morphological characters and phylogeny inferred from the multi-gene sequences data (ITS, LSU, TUB2, and TEF) analyses, which four new species (A. biseriale, A. cyclobalanopsidis, A. gelatinosum, and A. septatum) and seven known species (A. arundinis, A. garethjonesii, A. guizhouense, A. hydei, A. neosubglobosa, A. phyllostachium and A. psedoparenchymaticum) are introduced and identified, respectively. The aim of this study is to describe these new taxa with detailed descriptions and illustrations, and also provide their phylogenetic relationships within Arthrinium based on multi-gene analysis.

 Materials and Methods Sample Collection, Morphological Studies and Isolation

Samples were collected from Guizhou and Guangdong Province in China. Fungal fruiting bodies were examined by using stereomicroscope (Motic SMZ 168). Free hand sections of fungal structures were mounted in water for microscopic studies and photomicrography. Images were taken by using a Nikon ECLIPSE Ni compound microscope fitted with a Canon EOS 70D digital camera. All measurements were taken by using Tarosoft Image Frame Work software (IFW) (Liu et al., 2010), and photo plates were processed with Adobe Photoshop CS6 software (Adobe Systems, United States).

The single spore isolation followed the method described in Senanayake et al. (2020b). Parts of morphological descriptions were based on sporulated cultures on WA (Water Agar) at room temperature (ca. 25°C). Type specimens were deposited in the herbarium of Cryptogams Kunming Institute of Botany Academia Sinica (HKAS), Kunming, China and Guizhou Academy of Agriculture sciences Herbarium (GZAAS). Pure cultures were deposited in China General Microbiological Culture Collection Center (CGMCC) and Guizhou Culture Collection (GZCC). Faces of Fungi1 number is obtained as described in the paper by Jayasiri et al. (2015), and the new taxa are registered in Index Fungorum (2021).

 DNA Extraction, PCR Amplification and Sequencing

Fungal mycelia were scraped from the pure culture which were growing on PDA (Potato Dextrose Agar) for one week at 25°C in dark. DNA was extracted by using Ezup Column Fungi Genomic DNA Purification Kit (Sangon Biotech, China) from fresh fungal mycelia, but some were extracted directly from fruiting bodies by using Forensic DNA Kit (Omega Bio-Tek, China). Four gene regions, large subunit rDNA (LSU), internal transcribed spacer (ITS), beta-tubulin (TUB2) and the translation elongation factor 1-alpha (TEF) gene were amplified by the primer pairs LR0R and LR5 (Vilgalys and Hester, 1990), ITS5 and ITS4, T1 (O’Donnell and Cigelnik, 1997) and Bt2b (Glass and Donaldson, 1995), EF1-728F and EF-2 (O’Donnell et al., 1998; Carbone and Kohn, 1999), respectively. Polymerase chain reaction (PCR) was carried out in 25 μL reaction volume containing 12.5 μL 2 × PCR Master Mix (Sangon Biotech, China), 9.5 μL ddH2O, 1 μL of each primer and 1 μL DNA template. The annealing temperatures were adjusted to 56°C for ITS, LSU and TUB2, and 55°C for TEF. PCR products were sent to sequence at Sangon Biotech Co., Ltd., China. The PCR products were examined using 1.2% agarose electrophoresis gel stained with ethidium bromide. PCR products were purified and sequenced by Sangon Biotech (Shanghai) Co., Ltd., China. New generated nucleotide sequences were submitted in GenBank (Table 1).

GenBank accession numbers of species included in the phylogenetic study.

Species Strain no. GenBank Accession Numbers
LSU ITS TEF TUB2
Arthrinium acutiapicum KUMCC 20–0209 MT946338 MT946342 MT947359 MT947365
A. acutiapicum KUMCC 20–0210 MT946339 MT946343 MT947360 MT947366
A. aquaticum MLFU 18–1628 MK835806 MK828608 N/A N/A
A. arundinis CBS 106.12 KF144927 KF144883 KF145015 KF144973
A. arundinis CBS 114316 KF144928 KF144884 KF145016 KF144974
A. arundinis GZCC 20–0116 MW478899 MW481720 MW522952 MW522968
A. aureum CBS 244.83 KF144935 AB220251 KF145023 KF144981
A. balearicum CBS 145129 MK014836 MK014869 MK017946 MK017975
A. bambusae LC7107 N/A KY494719 KY705117 KY705187
A. bambusae LC7106 KY494794 KY494718 KY806204 KY705186
A. bambusicola MFLUCC 20–0144 MW173087 MW173030 MW183262 N/A
A. biseriale CGMCC 3.20135 MW478885 MW481708 MW522938 MW522955
A. biseriale GZCC 20–0099 MW478886 MW481709 MW522939 MW522956
A. biseriale GZCC 20–0100 MW478887 MW481710 MW522940 MW522957
A. camellia-sinensis LC8181 KY494837 KY494761 KY705157 KY705229
A. camellia-sinensis LC5007 KY494780 KY494704 KY705103 KY705173
A. caricicola CBS 145127 MK014838 MK014871 MK017948 MK017977
A. chinense CFCC53036 N/A MK819291 MK818545 MK818547
A. chinense CFCC53037 N/A MK819292 MK818546 MK818548
A. chromolaenae MFLUCC 17-1505 MT214436 MT214342 N/A N/A
A. cyclobalanopsidis CGMCC 3.20136 MW478892 MW481713 MW522945 MW522962
A. cyclobalanopsidis GZCC 20–0103 MW478893 MW481714 MW522946 MW522963
A. descalsii CBS 145130 MK014837 MK014870 MK017947 MK017976
A. dichotomanthi LC8175 KY494831 KY494755 KY705151 kY705223
A. dichotomanthi LC4950 KY494773 KY494697 KY705096 KY705167
A. esporlense CBS 145136 MK014845 MK014878 MK017954 MK017983
A. euphorbiae IMI 285638b AB220335 AB220241 N/A AB220288
A. gaoyouense CFCC 52301 N/A MH197124 MH236793 MH236789
A. gaoyouense CFCC 52302 N/A MH197125 MH236794 MH236790
A. garethjonesii KUMCC16–0202 KY356091 KY356086 N/A N/A
A. garethjonesii GZCC 20–0115 MW478894 MW481715 MW522947 N/A
A. gelatinosum KHAS 11962 MW478888 MW481706 MW522941 MW522958
A. gelatinosum GZAAS 20–0107 MW478889 MW481707 MW522942 MW522959
A. guizhouense LC5318 KY494784 KY494708 KY705107 KY705177
A. guizhouense LC5322 KY494785 KY494709 KY705108 KY705178
A. guizhouense GZCC 20–0114 MW478895 MW481716 MW522948 MW522964
A. gutiae CBS 135835 KR149063 KR011352 KR011351 KR011350
A. hispanicum IMI 326877 AB220336 AB220242 N/A AB220289
A. hydei CBS 114990 KF144936 KF144890 KF145024 KF144982
A. hydei KUMCC 16–0204 KY356092 KY356087 N/A N/A
A. hydei GZCC 20–0113 MW478900 MW481721 MW522953 N/A
A. hyphopodii KUMCC 16–0201 KY356093 KY356088 N/A N/A
A. hyphopodii MFLUCC15–0003 N/A KR069110 N/A N/A
A. hysterinum CBS 145134 MK014843 MK014876 N/A N/A
A. hysterinum ICMP 6889 MK014841 MK014874 MK017951 MK017980
A. ibericum CBS 145137 MK014846 MK014879 MK017955 MK017984
A. italicum CBS 145138 MK014847 MK014880 MK017956 MK017985
A. japonicum IFO 30500 AB220356 AB220262 N/A AB220309
A. japonicum IFO 31098 AB220358 AB220264 N/A AB220311
A. jatrophae MMI 00052 N/A JQ246355 N/A N/A
A. jatrophae AMH–9557 N/A JQ246355 N/A N/A
A. jiangxiense LC4577 KY494769 KY494693 KY705092 KY705163
A. jiangxiense LC4578 KY494770 KY494694 KY705093 KY705164
A. kogelbergense CBS 113332 KF144937 KF144891 KF145025 KF144983
A. kogelbergense CBS 113333 KF144938 KF144892 KF145026 KF144984
A. locuta-pollinis LC11683 N/A MF939595 MF939616 MF939622
A. longistromum MFLUCC 11–0481 KU863129 KU940141 N/A N/A
A. longistromum MFLUCC 11–0479 KU863130 KU940142 N/A N/A
A. malaysianum CBS 102053 KF144942 KF144896 KF145030 KF144988
A. malaysianum CBS 251.29 KF144943 KF144897 KF145031 KF144989
A. marii CBS 497.90 KF144947 AB220252 KF145035 KF144993
A. mediterranei IMI 326875 AB220337 AB220243 N/A AB220290
A. minus CBS 145131 MK014839 MK014872 MK017949 MK017978
A. mytilomorphum DAOM 214595 N/A KY494685 N/A N/A
A. garethjonesii KUMCC 18–0192 MK070898 MK070897 N/A N/A
A. neosubglobosa KUMCC 16–0203 KY356095 KY356090 N/A N/A
A. neosubglobosa JHB006 KY356094 KY356089 N/A N/A
A. neosubglobosa GZAAS 20–0099 MW478901 MW481705 MW522954 MW522969
A. obovatum LC8177 KY494833 KY494757 KY705153 KY705225
A. obovatum LC4940 KY494772 KY494696 KY705095 KY705166
A. ovatum CBS 115042 KF144950 KF144903 KF145037 KF144995
A. paraphaeospermum MFLUCC 13–0644 KX822124 KX822128 N/A N/A
A. phaeospermum CBS 114314 KF144951 KF144904 KF145038 KF144996
A. phaeospermum CBS 114315 KF144952 KF144905 KF145039 KF144997
A. phragmites CPC 18900 KF144956 KF144909 KF145043 KF145001
A. phyllostachium MFLUCC 18–1101 MH368077 MK351842 MK340918 MK291949
A. phyllostachium GZCC 20–0111 MW478896 MW481717 MW522949 MW522965
A. phyllostachium GZCC 20–0112 MW478897 MW481718 MW522950 MW522966
A. piptatheri CBS 145149 MK014860 MK014893 MK017969 N/A
A. pseudoparenchymaticum LC7234 KY494819 KY494743 KY705139 KY705211
A. pseudoparenchymaticum LC8173 KY494829 KY494753 KY705149 KY705221
A. pseudoparenchymaticum GZCC 20–0117 MW478898 MW481719 MW522951 MW522967
A. pseudorasikravindrae KUMCC 20–0208 N/A MT946344 MT947361 MT947367
A. pseudorasikravindrae KUMCC 20–0211 N/A MT946345 MT947362 MT947368
A. pseudosinense CPC 21546 KF144957 KF144910 KF145044 N/A
A. pseudosinense CBS 135459 N/A KF144910 KF145044 N/A
A. pseudospegazzinii CBS 102052 KF144958 KF144911 KF145045 KF145002
A. pterospermum CBS 123185 KF144959 KF144912 N/A KF145003
A. pterospermum CPC 20193 KF144960 KF144913 KF145046 KF145004
A. puccinioides CBS 145150 MK014861 MK014894 MK017970 MK017998
A. puccinioides CBS 549.86 AB220347 AB220253 N/A AB220300
A. qinlingense CFCC 52303 N/A MH197120 MH236795 MH236791
A. qinlingense CFCC 52304 N/A MH197121 MH236796 MH236792
A. rasikravindrae CBS 145152 MK014863 MK014896 MK017971 MK017999
A. rasikravindrae LC7115 KY494797 KY494721 KY705118 KY705189
A. rasikravindrae NFCCI 2144 N/A JF326454 N/A N/A
A. sacchari CBS 212.30 KF144963 KF144917 KF145048 KF145006
A. sacchari CBS 301.49 KF144962 KF144916 KF145047 KF145005
A. saccharicola CBS 191.73 KF144966 KF144920 KF145051 KF145009
A. saccharicola CBS 463.83 KF144968 KF144921 KF145053 KF145011
A. septatum CGMCC 3.20134 MW478890 MW481711 MW522943 MW522960
A. septatum GZCC 20–0109 MW478891 MW481712 MW522944 MW522961
A. serenense IMI 326869 AB220344 AB220250 N/A AB220297
A. setostromum KUMCC 19–0217 MN528011 MN528012 MN527357 N/A
A. sporophleum CBS 145154 MK014865 MK014898 MK017973 MK018001
A. subglobosum MFLUCC 11–0397 KR069113 KR069112 N/A N/A
A. subroseum LC7292 KY494828 KY494752 KY705148 KY705220
A. thailandicum MFLUCC 15–0199 KX986111 KU940146 N/A N/A
A. thailandicum MFLUCC 15–0202 KU863133 KU940145 N/A N/A
A. trachycarpum CFCC 53038 N/A MK301098 MK303396 MK303394
A. trachycarpum CFCC 53039 N/A MK301099 MK303397 MK303395
A. urticae IMI 326344 AB220339 AB220245 N/A N/A
A. vietnamese IMI 99670 KX986111 KX986096 N/A KY019466
A. xenocordella CBS478.86 KF144970 KF144925 KF145055 KF145013
A. xenocordella CBS 595.66 KF144971 KF144926 N/A N/A
A. yunnanum DDQ 00281 KU863136 KU940148 N/A N/A
A. yunnanum MFLU 15–0002 N/A KU940147 N/A N/A
Seiridium phylicae CPC 19962 NG 042759 LT853092 LT853189 LT853239
Seiridium phylicae CPC 19965 KC005809 LT853093 LT853190 LT853240
The newly generated sequence is shown in bold. AMH: Ajrekar Mycological herbarium, Pune, Maharashtra, India; CBS: Westerdijk Fungal Biodiversity Institute, Utrecht, Netherlands; CFCC: China Forestry Culture Collection Center, Beijing, China; CGMCC: China General Microbiological Culture Collection Center, Beijing, China; CPC: Culture collection of Pedro Crous, housed at the Westerdijk Fungal Biodiversity Institute; DAOM: Canadian Collection of Fungal Cultures, Ottawa, Canada; DDQ: D.Q. Dai; GZAAS: Guizhou Academy of Agricultural Sciences herbarium, China; GZCC: Guizhou Culture Collection, China; HKAS: Herbarium of Cryptogams Kunming Institute of Botany Academia Sinica; ICMP: International Collection of Microorganisms from Plants, New Zealand; IFO: Institute for Fermentation, Osaka, Japan; IMI: Culture collection of CABI Europe UK Centre, Egham, UK; JHB: H.B. Jiang; KUMCC: Culture collection of Kunming Institute of Botany, Yunnan, China; LC: Working collection of Lei Cai, housed at CAS, China; MFLUCC: Mae Fah Luang University Culture Collection, Chiang Rai, Thailand; NFCCI: National Fungal Culture Collection of India. Phylogenetic Analyses

Phylogenetic analyses were performed based on ITS, LSU, TUB2 and TEF sequence data. The related strains of Apiosporaceae (Table 1) used for analysis were referred to BLAST2 results and relevant publications (Wang et al., 2018; Jiang et al., 2019, 2020; Pintos et al., 2019; Tang et al., 2020). Sequences were obtained from GenBank and aligned using MAFFT v. 7 (Katoh and Standley, 2013). Manual adjustment was also performed when it is necessary by using BioEdit v. 7.0 (Hall, 1999). The alignment of sequences data used in analyses is deposited in TreeBASE under the accession number S27728. The analyses of maximum parsimony (MP), maximum likelihood (ML) and Bayesian inference (BI) were carried out as detailed in Dissanayake et al. (2020a) and programs used including PAUP v.4.0b 10 (Hillis and Bull, 1993; Swofford, 2002), raxmlGUI v. 1.3 (Silvestro and Michalak, 2012), and MrBayes v3.1.2 (Rannala and Yang, 1996; Huelsenbeck and Ronquist, 2001; Zhaxybayeva and Gogarten, 2002; Nylander, 2004). Trees were visualized with FigTree v1.4.2 (Rambaut, 2012) and the layout was edited using Adobe Illustrator CS6.

 Results Phylogeny

To determine the phylogenetic placement of the new collections in this study, the combined ITS, LSU, TUB2 and TEF data set comprised 119 taxa with Seiridium phylicae (CPC 19962 and CPC 19965) as the outgroup taxa. The concatenated alignment comprises 2,770 characters (ITS: 1–635; LSU: 636–1,454; TUB2: 1,455–2,300; TEF: 2,301–2,770) including gaps, of which 1,361 characters were constant, and 1,279 characters are parsimony informative and 130 are parsimony uninformative. Maximum likelihood, maximum parsimony and Bayesian analyses were performed, respectively, and presented consistent topologies. The best scoring RAxML tree (Figure 1) is obtained with a final likelihood value of -27544.434044. Estimated base frequencies were as follows: A = 0.236829, C = 0.253015, G = 0.251523, T = 0.258634; substitution rates AC = 1.154254, AG = 2.738844, AT = 1.073582, CG = 0.896658, CT = 4.134885, GT = 1.000000; The gamma distribution shape parameter alpha is equal to 0.332641 and the Tree-Length equal to 3.795226.

RAxML tree of representatives based on a combined dataset of ITS, LSU, TUB2 and TEF sequences. Bootstrap support values for ML, MP (≥75%) and Bayesian (≥0.95) are given at the nodes (ML/MP/BI). Branches with ML, MP and BI equal 100, 100 and 1 are in bold. The tree is rooted with Seiridium phylicae (CPC 19962 and CPC 19965). New strains are shown in red.

Phylogenetic analyses showed that our newly collected seventeen taxa clustered into eleven clades and can be recognized as seven known species (Arthrinium arundinis, A. garethjonesii, A. guizhouense, A. hydei, A. neosubglobosa, A. phyllostachium, A. psedoparenchymaticum) and four new species (A. biseriale, A. cyclobalanopsidis, A. gelatinosum, A. septatum) (Figure 1).

 Taxonomy <italic>Arthrinium biseriale</italic> Y. Feng and Z.Y. Liu, sp. nov. <xref ref-type="fig" rid="F2">Figure 2</xref>

Index Fungorum number: IF558136

Arthrinium biseriale (HKAS 111961, holotype). (A) Appearance of stromata on bamboo host. (B) Vertical section of stroma. (C) Peridium. (D) Paraphyses. (E) Germinating ascospore. (F–H) Asci. (I–K) Ascospore. (L) Culture. (M) Hyphae. (N,O) Conidiophore and conidiogenous cells. (P–T) Conidia. Scale bars: (B) = 50 μm. (C) = 20 μm. (D) = 10μm. (E–H) = 20 μm. (I–K) = 10 μm. (M) = 20 μm. (N) = 10 μm. (O) = 20 μm. (P–T) = 5 μm.

Facesoffungi number: FoF 09569

Etymology: The epithet refers to the ascospores are arranged in two rows in the ascus.

Holotype: HKAS 111961

Saprobic on dead bamboo culms, forming black, lenticular spots on the host surface, with stromata breaking through raised cracks with black center, and merge with each other with age, forming an erumpent black mass visible at the naked eye. Sexual morph: Stromata scattered to gregarious, immersed to erumpent, later becoming superficial, dark brown to black, fusiform, forming a slit-like opening at the apex, multi-loculate, membranous, with a periphysate ostiole. Ascomata 122–153 μm high, 138–207 μm diam, arranged in rows, dark brown to black. Peridium 11–19 μm wide, composed of several layers of dark brown to hyaline cells of textura angularis. Hamathecium 3–4 μm wide, comprising dense, hyaline, septa paraphyses. Asci 84–116 μm × 18–25 μm (x¯ = 97 μm × 21 μm, n = 20), 8-spored, unitunicate, clavate, apically rounded, with an indistinct pedicel. Ascospores 22–28 μm × 7–11 μm (x¯ = 25 μm × 9 μm, n = 30), biseriate, fusiform, curved at the bottom, obtuse at both ends, slightly wider in the middle, hyaline, 1-septate, constricted at the septum, mostly curved at the lower cell, rarely straight, with a large upper cell and a small lower cell, smoothwalled. The lower cell has 1-guttulate, the upper cell has 1–3 big guttulate in the middle surrounded by multiple small guttulate with a shallow 4–7 μm thick gelatinous sheath in the early. Growing to a later stage, the guttulate filled the entire spore, and the gelatinous sheath dissolves easily. Asexual morph: On WA, Hyphae 2.5–6.0 μm diam, hyaline, branched, septate, some curled in a ring structure. Conidiophores 12.0–44.0 μm × 2.5–5.0 μm (x¯ = 20.0 μm × 3.5 μm, n = 20), straight or flexuous, smooth, thin-walled, unbranched, hyaline to pale brown, cylindrical, cyathiform, having transverse septa, often reduced to conidiogenous cells. Conidiogenous cells 5.0–22.0 μm × 2.5–5.0 μm (x¯ = 10.0 μm × 3.5 μm, n = 20), integrated, hyaline to pale brown, doliiform to ampulliform, or lageniform. Conidia 7–9 μm long (n = 30), brown, smooth in surface view, and 7–11 μm long (n = 30), lenticular, with a paler equatorial slit in side view, globose to ellipsoid with many guttules.

Culture characters

Ascospores germinated on WA within 24 h and germ tubes produced from middle and lower end. Colonies fast grown on PDA at 25°C, reached 7 cm in 7 days at 25°C. Colonies evenly tiled, with a large number of aerial hyphae, white, velvety, thin, gray-white on the reverse side and dirty white in the center.

 Materials examined

China, Guizhou Province, Chishui City, Zhuhai National Forest Park, on dead culms of bamboo, 10 July 2019, Yao Feng, CS19-17 (HKAS 111961, holotype; GZAAS 20–0102, isotype), ex-type living cultures, CGMCC 3.20135 = GZCC 20–0101. Ibid., on dead base of the bamboo stem, 10 July 2019, Yao Feng, CS 19-25 (GZAAS 20–0101), living culture, GZCC 20–0100. Ibid., on dead branch of bamboo, 11 July 2019, Ya-Ya Chen, CS 013 (GZAAS 20–0100), living culture, GZCC 20–099.

 Notes

Three strains representing Arthrinium biseriale clustered in a well-supported clade which are closely related to A. gelatinosum, but phylogenetically distinct and can be recognized as two different species (99% sequence similarity in ITS; 99% in TEF; 98% in TUB2). Morphologically, Arthrinium biseriale has smaller stromata (122–153 μm × 138–207 μm vs. 144–199 μm × 184–214 μm) and the spores of A. biseriale are more curved than those of A. gelatinosum.

 <italic>Arthrinium gelatinosum</italic> Y. Feng and Z.Y. Liu, sp. nov. <xref ref-type="fig" rid="F3">Figure 3</xref>

Index Fungorum number: IF558137

Arthrinium gelatinosum (HKAS 111962, holotype). (A,B) Appearance of stromata on bamboo host. (C) Vertical section of stroma. (D) Peridium. (E–I) Asci. (J–N) Ascospore. Scale bars: (C) = 50 μm. (D–I) = 20 μm. (J–N) = 10 μm.

Facesoffungi number: FoF 09570

Etymology: The epithet refers to the ascospore surrounded by gelatinous sheath.

Holotype: HKAS 111962

Saprobic on dead bamboo culms, forming black, lenticular spots on the host surface, with stromata breaking through raised cracks with black center. Sexual morph: Stromata solitary to gregarious, immersed to erumpent, fusiform, with long axis broken at the top by one cracks. Ascomata 144–199 μm high μm × 184–214 μm wide, uniseriate or irregularly arranged beneath stromata, pseudothecial, black, globose to subglobose with a flattened base. Peridium composed of 5 or 6 layers of brown cells arranged in textura angularis, with a conspicuous perfusate ostiole. Hamathecium paraphyses hyphae-like. Asci 85–121 μm × 15–24 μm (x¯ = 100 μm × 17 μm, n = 20), 8-spored, unitunicate, clavate, apically rounded, broadly cylindrical, with an indistinct pedicel. Ascospores (27−) 28-31 (−32) μm × 6–8 μm (x¯ = 30 μm × 7 μm, n = 30), apiosporic, clavate to fusiform with narrowly rounded ends, composed of a large guttate and small guttate, hyaline, smooth-walled, surrounded by a gelatinous sheath. Growing to a later stage, the guttate filled the entire spore, and the gelatinous sheath dissolves easily. Asexual morph: undetermined.

Materials examined

China, Guizhou Province, Chishui City, Zhuhai National Forest Park, on dead culms of bamboo, 10 July 2019, Yao Feng, CS19-32 (HKAS 111962, holotype; GZAAS20–0108, isotype). Ibid., Chishui National Scenic Area, on dead branch of bamboo, 10 July 2019, Yao Feng, CS 19–29 (GZAAS 20–0107).

 Notes

Two taxa representing Arthrinium gelatinosum cluster in a well-supported lineage (ML/MP/BI = 93/98/1, Figure 1), which is a sister to A. biseriale, and they are phylogenetically distinct species.

 <italic>Arthrinium septatum</italic> Y. Feng and Jian K. Liu, sp. nov. <xref ref-type="fig" rid="F4">Figure 4</xref>

Index Fungorum number: IF558138

Arthrinium septatum (HKAS 111960, holotype). (A) Appearance of stromata on bamboo host. (B) Vertical section of stroma. (C) Peridium. (D) Germinating ascospore. (E) Paraphyses. (F,G) Culture. (H–J) Asci. (K–P) Ascospore. (Q) Colony on PDA producing conidia masses. (R–T) Conidiophore and conidiogenous cells. (U–X) Conidia. (Y,Z) Sterile cell. Scale bars: (B) = 50 μm. (C,D) = 25 μm. (E) = 10 μm. (H–J) = 20 μm. (K–P) = 10 μm. (R–T) = 10 μm. (U–Z) = 5 μm.

Facesoffungi number: FoF 09571

Etymology: The epithet refers to the septate conidiophore.

Holotype: HKAS 111960

Saprobic on dead bamboo culms. Sexual morph: Stromata scattered to gregarious, immersed to erumpent, initially breaks through a black spot on the host, later visible as black, raised, lenticular or dome-shaped, and will grow into a linear shape at the later stage of growth. Ostiolate, with the long axis broken at the top revealing the ostioles of pseudothecia. Ascomata 88–195 μm high × 160–185 μm wide (x¯ = 140 μm × 173 μm, n = 10), arranged in rows, brown to dark brown, subglobose with a flattened base. Peridium with several layers of cells arranged in textura angularis, with a conspicuous ostiole 50–90 μm in diameter, periphysate. Hamathecium paraphyses hyphae-like, septate, hyaline. Asci 75–104 μm × 17–26 μm (x¯ = 91 μm × 20 μm, n = 20), 8-spored, clavate, cylindrical, apically rounded, with distinct pedicel. Ascospores (24−) 25–30 (−32) μm × (6−) 8–10 (−11) μm (x¯ = 29 μm × 9 μm, n = 30), biseriate, broad fusiform to cylindrical, with a large upper cell and a small lower cell, hyaline, 1-septate, constricted at septum, slightly curved, smooth-walled, with many guttules, with a large guttule at the center of large upper cell, with a distinct gelatinous sheath. Asexual morph: On PDA, Hyphae 2–4 μm in diameter, hyaline, branched, septate. Conidiophores 12.0–63.0 × 2–5 (x¯ = 313 μm × 3 μm, n = 20), straight or flexuous, smooth, thin-walled, septate, hyaline to light brown, cylindrical, sometimes reduced to conidiogenous cells. Conidiogenous cells 4.0–18.0 × 1.5–4.0 (x¯ = 10.0 μm × 2.5 μm, n = 20), solitary on hyphae, integrated, branched, ampuliform, cylindrical, hyaline to brown. Conidia 8–11 (−13) μm long (n = 30), brown, smooth, guttulate, globose to ellipsoid in surface view. and (8−) 9–13 (−14) μm long (n = 30), lenticular with a paler equatorial slit in side view. Sterile cells (13−) 14–21 (−27) μm × 5–7 (−9) μm elongated, mixed among conidia.

Culture characteristics

Ascospores germinated on WA within 24 h. Colonies on PDA reached 8 cm in 7 days at 25 °C, flat, aerial mycelium white. The hyphae in the center are cottony, dense, and there is a thin circle of hyphae at the edge. Reverse grayish white with a dirty white patch.

 Materials examined

China, Guizhou Province, Chishui City, Zhuhai National Forest Park, on dead culms of bamboo, 10 July 2019, Yao Feng, CS19-8 (HKAS 111960, holotype; GZAAS 20–0109, isotype), ex-type living culture CGMCC 3.20134 = GZCC20–0108. Ibid., on dead branch of bamboo, 11 July 2019, Ya-Ya Chen, CS 025 (GZAAS 20–0111), living culture GZCC 20–0109.

 Notes

Two isolates, representing Arthrinium septatum, grouped in a well-supported clade and appear to be distinct from other Arthrinium species phylogenetically (Figure 1). Arthrinium septatum resembles to A. biseriale in having biseriate, broad fusiform to cylindrical ascospores and cylindrical, clavate asci. However, Arthrinium septatum differs from A. biseriale by having smaller stromata (160–185 μm diam vs. 138–207 μm diam) and asci (75–104 × 17–26 μm vs. 84–116 μm × 18–25 μm).

 <italic>Arthrinium cyclobalanopsidis</italic> Y. Feng and Jian K. Liu, sp. nov. <xref ref-type="fig" rid="F5">Figure 5</xref>

Index Fungorum number: IF558139

Arthrinium cyclobalanopsidis (HKAS 111963, holotype) (A) Conidia masses on host. (B) Culture. (C) Sterile cell mixed among conidia. (D) Hyphae of chain structure. (E–H) Conidiogenous cells and conidia. (I–L) Conidia. Scale bars: (C–H) = 10 μm. (I–L) = 5 μm.

Facesoffungi number: FoF 09572

Etymology: The epithet “cyclobalanopsidis” refers to the host plant, Cyclobalanopsidis glauca (Thunb.) Oerst.

Holotype: HKAS 111963

Saprobic on Cyclobalanopsidis glauca (Thunb.). Sexual morph: Undetermined. Asexual morph: On PDA, Hyphae 2.5–5.5 μm in diameter, hyaline, septate, branched with chain structure. Conidiophores reduced to the conidiogenous cells. Conidiogenous cells 6.0–19.0 μm × 2.5–7.0 μm (x¯ = 11.0 μm × 4.5 μm, n = 20), aggregated in clusters on hypha, pale brown, ampuliform or cylindrical. Conidia 8–12 μm long (n = 30), brown, smooth, globose to ellipsoid in surface view, and 10–14 μm long (n = 30), lenticular, with a paler equatorial slit in side view. Sterile cells elongated, rolled up, sometimes mixed among conidia.

Culture characteristics

Conidia germinated on WA within 12 h. Sporulated on PDA, Colonies flat, margin circular, fluffy, sparse, white, with dirty white patches in center, reverse white, with sparse aerial mycelium, reached 8 cm in 7 days at 25°C.

 Material examined

China, Guizhou Province, Qianxinan Buyi and Miao Autonomous Prefecture, Ceheng County, on Leaf of cyclobalanopsidis glauca (Thunb.) Oerst., 13 May 2018, Yao Feng, G81 (HKAS 111963, holotype; GZAAS 20–0096, isotype), ex-type living cultures, CGMCC 3.20136 = GZCC 20–0102. Ibid., 20 Oct. 2019, Yao Feng, G82 (GZAAS 20–0097), living culture GZCC 20–0103.

 Notes

Two isolates, representing Arthrinium cyclobalanopsidis, cluster together with A. camelliae-sinensis which was introduced by Wang et al. (2018) from Camellia sinensis (Figure 1). Arthrinium cyclobalanopsidis can be distinguished from A. camelliae-sinensis (567/572 in ITS; 390/414 in TEF; 715/748 in TUB2). Morphologically, Arthrinium cyclobalanopsidis resembles to A. camelliae-sinensis in having similar conidia (8–12 μm × 10–14 μm vs. 9.0–13.5 μm × 7.0–12.0 μm), but can be distinguished by its relatively longer conidiogenous cells (6.0–19.0 μm vs. 4.0–9.5 μm).

 <italic>Arthrinium garethjonesii</italic> D.Q. Dai and H.B. Jiang, Mycosphere 7 (9): 1337 (2017). <xref ref-type="fig" rid="F6">Figure 6</xref>

Saprobic on dead bamboo branch. Sexual morph: See Dai et al. (2016). Asexual morph: Sporodochia on host with hair-like setae, also grow in the gaps of the perithecia and scatter on the surface of the perithecia, black. Conidiophores reduced to conidiogenous cells. Conidiogenous cells (5−) 6–19 (−20) μm × (2−) 3–5 (−7) μm (x¯ = 11 μm × 4 μm, n = 20), aggregated in black sporodochia, hyaline to pale brown, smooth, ampulliform. Conidia (14–) 16–19 (–20) μm diam, brown, smooth, granular, globose to subglobose in surface view, and (16−) 17–22 (−23) μm diam, with pale equatorial slit in side view.

Arthrinium garethjonesii (GZAAS 20–0117) (A,B) Appearance of sporodochia on bamboo host. (C) Germinating conidia. (D) Conidia with setae. (E–K) Conidiogenous cells and conidia. (L–O) Conidia. Scale bars: (C) = 30 μm. (D) = 50 μm. (E) = 20 μm. (F,G) = 10 μm. (H) = 5 μm. (I,J) = 10 μm. (K–O) = 5 μm.

 Culture characteristics

Conidia germinated on WA within 12 h, colonies fast growing on PDA, reached 8 cm in 7days at 25°C, fluffy, circular, dense, raised at center, white, reverse reddish. Hyphae 2–4 μm diam, hyaline to pale brown, branched, septate.

 Material examined

China, Guizhou Province, Chishui City, Zhuhai National Forest Park, on dead branches of bamboo, 10 July 2019, Yao Feng, CS19-9 (GZAAS 20–0117); living culture GZCC 20–0115.

 Notes

Arthrinium garethjonesii was originally described by Dai et al. (2016) based on the sexual morph from dead bamboo culms (HKAS 96289) collected from Yunnan Province, China. Our phylogenetic result (Figure 1) indicates that our collection is identical to Arthrinium garethjonesii and we report its asexual morph for the first time in this study.

 <italic>Arthrinium guizhouense</italic> M. Wang and L. Cai, Mycokeys 34: 13 (2018). <xref ref-type="fig" rid="F7">Figure 7</xref>

Saprobic on dead bamboo culms, forming black, lenticular spots on the host surface, stromata breaking through raised cracks with black center. Sexual morph: Stromata solitary to gregarious, immersed to erumpent, fusiform, with long axis broken at the top by one cracks. Ascomata 188–220 μm high × 170–200 μm wide, uniseriate or irregularly arranged beneath stromata, pseudothecial, black, globose to subglobose. Peridium composed of 5 or 6 layers of brown cells arranged in textura angularis, Hamathecium paraphyses 3–5 μm, hyaline, hyphae-like, septate. Asci (80−) 94–106 (−107) μm × (20−) 21–23 (−24) μm, 8-spored, clavate, apically rounded, broadly cylindrical, with an indistinct pedicel. Ascospores (24−) 25–32 (−33) μm × (6−) 7–9 (−10) μm (x¯ = 31 μm × 8 μm, n = 30), apiosporic, clavate to fusiform with narrowly rounded ends, composed of a large upper cell and small lower cell, hyaline, smooth-walled, surrounded an inconspicuous gelatinous sheath. Asexual morph: Hyphae 2.5–7.5 μm diam, hyaline, branched, septate. Conidiophores reduced to conidiogenous cells. Conidiogenous cells 4–12 μm × 2–5 μm (x¯ = 8 μm × 3 μm, n = 20), erect, aggregated in clusters on hyphae, pale brown, smooth, subglobose, ampulliform or doliiform. Conidia 5–8 μm long (n = 30), dark brown to black, smooth, globose or subglobose, and 6–8 μm long (n = 30), lenticular, with a paler equatorial slit in side view. Sterile cells elongated, rolled up, sometimes mixed among conidia.

Arthrinium guizhouense (GZAAS 20–0114). (A) Appearance of stromata on bamboo host. (B) Vertical section of stroma. (C) Peridium. (D–F) Asci. (G) Germinating ascospore. (H,I) Culture. (J–O) Ascospore. (P) Colony on WA producing conidia masses. (Q,R) Conidiogenous cells giving rise to conidia. (S–V) Conidia. (W) Sterile cell. Scale bars: (B,C) = 50 μm. (D–F) = 30 μm. (G) = 50 μm. (J–O) = 20 μm. (Q,R) = 10 μm. (S–W) = 5 μm.

 Culture characteristics

On PDA, colonies very fast, reached 8 cm in 8 days at 25°C, velvety, circular, with regular edge, middle densely and raised white, dense at above the from margin, aerial mycelia, surface initially white, became grayish and reverse white.

 Material examined

China, Guangdong Province, Guangzhou City, on decaying bamboo culms, 03 Sep. 2019, Yao Feng, GZ 23 (GZAAS 20–0114); living culture GZCC 20–0114.

 Notes

Arthrinium guizhouense was introduced from air in a karst cave (asexual morph was provided from the culture) in Guizhou province, China by Wang et al. (2018). In this study, one collection was found as saprobe on bamboo in Guangzhou, China and it is identified as A. guizhouense based on the phylogeny and morphology evidences. In addition, our new collection provides the sexual morph which only the asexual morph was illustrated by Wang et al. (2018) and Senanayake et al. (2020a).

 <italic>Arthrinium phyllostachium</italic> C.L. Yang, X.L. Xu and K.D. Hyde, Phytotaxa 406 (2): 102 (2019). <xref ref-type="fig" rid="F8">Figure 8</xref>

Saprobic on dead bamboo culms, Sexual morph: Stromata scattered to gregarious, immersed to erumpent, later becoming superficial, dark brown to black, fusiform, forming a slit-like opening at the apex, with stromata breaking through raised cracks with black center. Ascomata 135–185 μm high, 157–215 μm diam, multi-loculate, with a periphysate ostiole, arranged in rows, clustered, gregarious, ampulliform, dark brown to black. Peridium 20–25 μm wide, composed of several layers of dark brown to brown cells of textura angularis. Hamathecium 3–5 μm wide, comprising dense, hyaline, septate paraphyses, hyphae-like. Asci 66–98 × 17–27 (x¯ = 85 μm × 21 μm, n = 20), 8-spored, unitunicate, clavate, apedicellate, apically rounded. Ascospores 29–34 μm × 7–10 μm (x¯ = 32 μm × 9 μm, n = 30), biseriate, elliptical, hyaline, 1-septate, constricted at the septum, mostly curved at the lower cell, rarely straight, with a large upper cell and a small lower cell, smooth-walled, with a shallow gelatinous sheath. Asexual morph: On WA, Hyphae 1.5–4.0 μm in diameter, hyaline, septate, branched. Conidiophores reduced to the conidiogenous cells. Conidiogenous cells (8−) 9–28 (−31.5) μm × (1.5−) 2–4 (−6) μm (x¯ = 20 μm × 3 μm, n = 20), aggregated in clusters on hypha or solitary, erect, ampuliform or cylindrical, arising holoblastically from vegetative hyphae, monoblastic, or polyblastic, sympodial, terminal, cylindrical to clavate, ampulliform, hyaline, smooth, thin-walled. Conidia 5–8 μm long (n = 30), brown, smooth, globose to ellipsoid in surface view, and 7–9 μm long (n = 30), lenticular, with a paler equatorial slit in side view. Sterile cells light brown, elongated, and occasionally irregularly angled.

Arthrinium phyllostachium (GZAAS 20–0112) (A) Appearance of stromata on bamboo host. (B) Vertical section of stroma. (C) Peridium. (D) Germinating ascospore. (E) Paraphyses. (F–I) Asci. (J–M) Ascospore. (N,O) Culture. (P–S) Conidiogenous cells and conidia. Scale bars: (B) = 50 μm. (C) = 10 μm. (D) = 20 μm. (E) = 20 μm. (F–I) = 30 μm. (J–M) = 10 μm. (P,Q) = 20 μm. (R–S) = 10 μm.

 Culture characters

Ascospores germinated on WA within 24 h and germ tubes produced from Upper, middle and lower end. Colonies fast growed on PDA at 25°C, flat, spreading, the middle is white, smooth, the edge surface tapetum, gray-white, indistinct aerial hyphae, the reverse side is yellowish in the middle, and the edge is grayish white.

 Materials examined

China, Guizhou Province, Chishui City, Zhuhai National Forest Park, on dead culms of bamboo, 10 July 2019, Yao Feng, CS 19-23 (GZAAS 20–0112), living culture GZCC 20–0111; Ibid., Chishui National Scenic Area, on dead culms of bamboo, 10 July 2019, Ya-Ya Chen, CS004 (GZAAS 20–0113), living culture GZCC 20–0112.

 Notes

Arthrinium phyllostachium was introduced by Yang et al. (2019) based on the asexual morph and phylogeny analyses. It was collected from culms of Phyllostachys heteroclada (Poaceae) in China (Yang et al., 2019). The phylogenetic results showed that our new collections are identical to A. phyllostachium, Yang et al. (2019) only provided the asexual morph and the sexual morph is given in this study.

 <italic>Arthrinium pseudoparenchymaticum</italic> M. Wang and L. Cai, Mycokeys 34 (1): 17 (2018), <xref ref-type="fig" rid="F9">Figure 9</xref>

Saprobic on dead bamboo culms, forming black, lenticular spots on the host surface, with stromata breaking through raised cracks with black center. Sexual morph: Ascomata 187–242 μm high × 242–373 μm wide, uniseriate, or irregularly arranged beneath stromata, black, globose to subglobose with a flattened base. Peridium composed of 5–7 layers of brown cells arranged in textura angularis, with a conspicuous perfusate ostiole. Hamathecium paraphyses 4–8 μm, hyphae-like, septa hyaline. Asci (95−) 107–110 (−133) μm × 23–25 (−27) μm, 8-spored, broadly cylindrical, clavate or subglobose, apically rounded, with an indistinct pedicel. Ascospores (35–) 35–43 (–44) × (10–) 11–13 μm (x¯ = 41 × 12, n = 30), apiosporic, clavate to fusiform with narrowly rounded ends, composed of a large upper cell and small lower cell, hyaline, smooth-walled, surrounded by a gelatinous sheath. Asexual morph: On WA, Hyphae 1.5–4 μm diam, hyaline to pale brown, branched, septate. Conidiophore extends from the vegetative hypha, up to 60 μm long. Conidiogenous cells 10.0–40.0 μm × 3.0–6.0 μm, scattered in clusters on hyphae, smooth, unbranched, hyaline to pale yellow, smooth, erect, subcylindrical. Conidia 17–27 μm × 17–21 μm (x¯ = 23 μm × 19 μm, n = 30), pale to light brown, smooth, globose to subglobose, sometimes lobed or dentate, polygonal or irregular in surface view.

Arthrinium pseudoparenchymaticum (GZAAS 20–0115) (A,B) Appearance of stromata on bamboo host. (C) Vertical section of stroma. (D) Paraphyses. (E) Peridium. (F) Germinating ascospore. (G) Culture. (H–J) Asci. (K–O) Ascospore. (P) Ascospore in Indian ink and present clear gelatinous sheath. (Q) Colony on WA producing conidia masses. (R) Dentate conidia. (S–U) Conidiogenous cells giving rise to conidia. Scale bars: (C) = 50 μm. (D–F) = 20 μm. (H–J) = 30 μm. (K–P) = 15 μm. (R–U) = 15 μm.

 Culture characteristics

Ascospores germinating on WA within 24 h and germ tubes produced from upper. Colonies fast growing on PDA at 25°C, under 12 h light/12 h dark, cottony, circular, sparse, raised, with irregular edge, white in center.

 Material examined

China, Guangdong Province, Guangzhou City, on decaying bamboo culms, 3 Sep. 2019, Yao Feng, GZ18 (GZAAS 20–0115), living culture GZCC20–0117.

 Notes

Arthrinium pseudoparenchymaticum was introduced by Wang et al. (2018) based on the asexual morph characters and phylogeny analyses. It was originally collected from bamboo in China (Wang et al., 2018). In this study, a fresh specimen was collected and it is identical to A. pseudoparenchymaticum (Figure 1), both sexual and asexual morphs were described and illustrated (Figure 9).

 <italic>Arthrinium arundinis</italic> (Corda) Dyko and B. Sutton, Mycotaxon 8: 119 (1979). <xref ref-type="fig" rid="F10">Figure 10</xref>.

Saprobic on dead bamboo culms. Asexual morph: On PDA, Hyphae 2–3 μm diam, consisting of smooth, hyaline, branched, septate. Conidiophores reduced to conidiogenous cells. Conidiogenous cells 3–8 μm × 2–5 μm, aggregated in clusters on hyphae, pale brown, smooth, ampulliform. Conidia (4–) 5–6 (–7) μm, brown, smooth, globose in surface view, and (4−) 5–7 (−8) μm diam, lenticular with pale equatorial slit in side view. Sterile cells at times intermingled among conidia. Sexual morph: Undetermined.

Arthrinium arundinis (GZAAS 20–0116) (A,B) culture. (C) Colonies on culture. (D) Sterile cell mixed among conidia. (E–J) Conidiogenous cells and conidia. (K–N) Conidia. Scale bars: (D) = 50 μm. (E) = 5 μm. (F) = 10 μm. (G–N) = 5 μm.

 Culture characteristics

The colony is flat, cotton-like, thick and dense, with sparse aerial mycelia. The surface of PDA is white and the reverse side is grayish white.

 Materials examined

China, Guizhou Province, Chishui City, Zhuhai National Forest Park, on dead culms of bamboo, 10 July 2019, Yao Feng, CS 19-7 (GZAAS 20–0116), living culture GZCC 20–0116.

 Notes

Our collection clusters together with the isolates of Arthrinium arundinis (Figure 1) and its morphology lines up with the type species. Therefore we identify it as Arthrinium arundinis.

 <italic>Arthrinium hydei</italic> Crous, IMA Fungus 4 (1): 142 (2013). <xref ref-type="fig" rid="F11">Figure 11</xref>

Saprobic on bamboo leaves. Asexual morph: Colonies on the host punctiform, pulvinate, blackish brown. Conidiophores pale brown, smooth, transversely septate, subcylindrical. Conidiogenous cells 5–15 × 3–6 μm, brown, smooth, subcylindrical to doliiform to lageniform. Conidia (13−) 14–19 (−20) μm diam in surface view, brown, roughened, globose, and 15–20 μm diam, lenticular with pale equatorial slit in side view. Sexual morph: Undetermined.

Arthrinium hydei (GZAAS 20–0098) (A,B) Colonies on substrate. (C–F) Conidiogenous cells and conidia. (G–M) Conidia. (N) Germinating conidia. Scale bars: (C) = 50 μm. (D–M) = 5 μm. (N) = 25 μm.

 Culture characteristics

Colonies flat, spreading, with sparse aerial mycelium. On PDA surface and reverse pale luteous. Mycelium consisting of smooth, hyaline to pale brown, branched, septate, 2.0–4.5 μm diam hyphae.

 Materials examined

China, Guizhou Province, Guiyang City, Baihua Lake, on bamboo leaves, 20 April 2018, Yao Feng, 67 (GZAAS 20–0098), living culture GZCC20–0113.

 Notes

This collection is identified as Arthrinium hydei based on both morphological characters and molecular data. Crous and Groenewald (2013) originally described A. hydei based on the asexual morph from a culture (CBS 114990) which was isolated from bamboo culms in Hong Kong, China; we found this species in Guizhou from the substrate in nature with its asexual morph.

 <italic>Arthrinium neosubglobosa</italic> D.Q. Dai and H.B. Jiang, Mycosphere 7 (9): 1337 (2017) <xref ref-type="fig" rid="F12">Figure 12</xref>.

Saprobic on dead bamboo culms. Sexual morph: Stromata scattered to gregarious, superficial to raised, with a slit-like opening, dark brown to black, naviculate, with black papillate ostiole, multi-loculate. Ascomata 205–328 μm high, 168–345 μm, perithecial, arranged in a row, immersed in stromata, later becoming erumpent through host surface to superficial, obpyriform to ampulliform, dark brown, membranous. Ostiole raised from center of Ascomata, internally lined with periphyses. Peridium 4 layers, outer layer composed of dark brown, cells of textura prismatica, inner layer thin, with hyaline cells of textura angularis. Hamathecium 4.0–5.5 μm wide, comprising dense paraphyses, indistinctly aseptate, unbranched, not anastomosing, filamentous, clustered embedded in gelatinous matrix. Asci 80–119 μm × 20–37 μm (x¯ = 97 μm × 28 μm, n = 20), 8-spored, unitunicate, clavate, with a short pedicel, apically rounded. Ascospores 25–36 μm × 11–15 μm (x¯ = 29 μm × 13 μm, n = 30), 2-seriate, elliptical, hyaline, 1-septate, constricted at the septum, mostly curved at the lower cell, rarely straight, with a large upper cell and a small lower cell, smoothwalled, 1-guttulate, with a shallow 8–12 μm thick gelatinous sheath. Asexual morph: Undetermined.

Arthrinium neosubglobosa (GZAAS 20–0099). (A,B) Appearance of stromata on bamboo host. (C) Vertical section of stroma. (D) Germinating ascospore. (E) Paraphyses. (F) Peridium. (G–K) Asci. (L–P) Ascospore. Scale bars: (C) = 100 μm. (D–F) = 20 μm. (G–K) = 30 μm. (L–P) = 20 μm.

 Materials examined

China, Guizhou Province, Zunyi City, Daozhen County, on dead culms of bamboo, 15 August 2018, Yao Feng, DZ22 (GZAAS 20–0099).

 Notes

Arthrinium neosubglobosa was introduced by Dai et al. (2016) based on the sexual morph characters and phylogeny analyses. The pure culture was attempted by single spore isolation and the DNA was extracted directly from the fruiting body, the new collection is identified as A. neosubglobosa based on the phylogeny (Figure 1) and morphology evidences.

 Discussion

Arthrinium species have been reported from many hosts, includes hive-stored pollen lichens, marine algae, soil debris, gut of insects and nodules of human skin (Sharma et al., 2014; Crous et al., 2015, Senanayake et al., 2015; Wijayawardene et al., 2017, Zhao et al., 2018), it can be concluded that Arthrinium is ecologically diverse. Bamboo, as one of the most reported host, is a gramineous plant integrating economy and ornamental value (Gratani et al., 2008; Kelchner and Bamboo Phylogeny Group, 2013; Dai et al., 2016, 2017; Jiang et al., 2018, 2019, 2020; Wang et al., 2018; Yang et al., 2019), there is more than 115 genera with approximately 1,450 species. According to incomplete statistics, more than 1,100 species of fungi on bamboo were reported (Hyde et al., 2002a, b; Dai et al., 2016, 2017; Senanayake et al., 2020a; Tang et al., 2020; Wijesinghe et al., 2020). It is of great significance to excavate and identify the fungi on bamboo.

Several studies have shown (Crous and Groenewald, 2013; Dai et al., 2016, Dai et al., 2017; Wang et al., 2018; Yang et al., 2019) that it is difficult to identify the Arthrinium species solely rely on morphology and the multi-gene phylogenetic analyses are needed in the identification and classification of Arthrinium. The morphology of conidia is variable which can be depending on the period of incubation on different habitats, for example, A. biseriale, A. gelatinosum and A. septatum, are very similar in morphology, but molecular data distinguish them into different species; Our collection A. pseudoparenchymaticum differs from the type specimen (LC 8173) in the morphology of conidiophores, the size of conidiogenous cells is also different, while the molecular data supported them as the same species. These results are in agreement with the previous observations and publications (Crous and Groenewald, 2013; Dai et al., 2016, Dai et al., 2017; Wang et al., 2018, Yang et al., 2019). In addition, as a high diverse group, it is also difficult to distinguish species within Arthrinium by only using ITS and LSU gene regions, and the protein genes (TEF and TUB2) are not available for many species in the genus which bring potential problem once the new or existing taxa are introduced and identified, respectively. For example the absent of the protein genes (TEF and TUB2) of Arthrinium garethjonesii would bring the troubles in identification of Arthrinium setostromum as it is hard to confirm whether they are same species or not as they are identical in ITS and LSU gene regions, as well as the close phylogenetic relationship (Figure 1). It would be necessary to provide protein genes when new taxa are introduced in these well-study and diverse groups.

 Data Availability Statement

The data presented in the study can be found in the Genbank. The accession numbers of the sequences deposited in GenBank are ITS: MW481705—MW481721; LSU: MW478885–MW478901; TEF: MW522938–MW522954; and TUB: MW522955–MW522969.

 Author Contributions

YF and J-KL: conceptualization. YF and Y-YC: methodology. YF, C-GL, and J-KL: formal analysis. YF, Y-YC, M-MX, and J-KL: resources. YF: writing—original draft preparation. C-GL, Z-YL, and J-KL writing—review and editing. Z-YL and J-KL: supervision. All authors approved to publish the version of final manuscript.

 Conflict of Interest

The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.

Funding. This study was supported by the Joint Fund of the National Natural Science Foundation of China and the Karst Science Research Center of Guizhou province (Grant No. U1812401); the Research of Featured Microbial Resources and Diversity Investigation in Southwest Karst area (Project No. 2014FY120100); and the Guizhou Graduate Research Funding: Taxonomic and Phylogenetic studies of microfungi from Bamboo in Guizhou (Qian Jiao He YJSCXJH [2019] 022).

We thank Ning-Guo Liu, Sheng-Nan Zhang, Jing Yang, Qiu-Jiu Shang, and Milan C. Samarakoon for their suggestions on phylogeny in this study.

 References Agut M. Calvo M. A. (2004). In vitro conidial germination in Arthrinium aureum and Arthrinium phaeospermum. Mycopathologia 157 363–367. 10.1023/B:MYCO.0000030432.08860.f3 Carbone I. Kohn L. M. (1999). A method for designing primer sets for speciation studies in filamentous ascomycetes. Mycologia 91 553–556. 10.1080/00275514.1999.12061051 Chen Y. Y. Dissanayake A. Liu Z. Y. Liu J. K. (2020). Additions to Karst Fungi 4: Botryosphaeria spp. associated with woody hosts in Guizhou province, China including B. guttulata sp. nov. Phytotaxa 454 186–202. 10.11646/phytotaxa.454.3.2 Chen Y. Y. Maharachchikumbura S. S. N. Liu J. K. Hyde K. D. Nanayakkara R. R. Zhu G. S. (2017). Fungi from asian karst formations I. Pestalotiopsis photinicola sp.nov., causing leaf spots of Photinia serrulata. Mycosphere 8 103–110. 10.5943/mycosphere/8/1/9 Crous P. W. Groenewald J. Z. (2013). A phylogenetic re-evaluation of Arthrinium. IMA Fungus 4 133–154. 10.5598/imafungus.2013.04.01.13 23898419 Crous P. W. Wingfield M. J. Le Roux J. J. Richardson D. M. Strasberg D. Shivas R. G. (2015). Fungal planet description sheets: 371-399. Persoonia 35 264–327. 10.3767/003158515X690269 26823636 Dai D. Q. Jiang H. B. Tang L. Z. Bhat D. J. (2016). Two new species of Arthrinium (Apiosporaceae, Xylariales) associated with bamboo from Yunnan, China. Mycosphere 7 1332–1345. 10.5943/mycosphere/7/9/7 Dai D. Q. Phookamsak R. Wijayawardene N. N. Li W. J. Bhat D. J. Xu J. C. (2017). Bambusicolous fungi. Fung. Divers. 82 1–105. Dissanayake A. J. Bhunjun C. S. Maharachchikumbura S. S. N. Liu J. K. (2020a). Applied aspects of methods to infer phylogenetic relationships amongst fungi. Mycosphere 11 2652–2676. 10.5943/mycosphere/11/1/18 Dissanayake A. J. Chen Y. Y. Liu J. K. (2020b). Unravelling diaporthe species associated with woody hosts from karst formations (Guizhou) in China. J. Fungi 6:251. 10.3390/jof6040251 33121032 Ellis M. B. (1971). Dematiaceous Hyphomycetes. Kew: Commonwealth Mycological Institute, 608. Feng Y. Zhang S. N. Liu Z. Y. (2019). Tremateia murispora sp. nov. (Didymosphaeriaceae, Pleosporales) from Guizhou, China. Phytotaxa 416 79–87. 10.11646/phytotaxa.416.1.10 Glass N. L. Donaldson G. C. (1995). Development ofprimer sets designed for use with the PCR to amplify conserved genes from filamentous ascomycetes. Appl. Environ. Microbiol. 61 1323–1330. 10.1128/aem.61.4.1323-1330.1995 7747954 Gratani L. Crescente M. F. Varone L. Fabrini G. Digiulio E. (2008). Growth pattern and photosynthetic activity of different bamboo species growing in the Botanical Garden of Rome. Flora Morphol. Distrib. Funct. Ecol. Plants 203 77–84. 10.1016/j.flora.2007.11.002 Hall T. A. (1999). “BioEdit: a user-friendly biological sequence alignment editor and analysis program for Windows 95/98/NT,” in Nucleic Acids Symposium Series. 95–98. Hillis D. M. Bull J. J. (1993). An empirical test of bootstrapping as a method for assessing confidence in phylogenetic analysis. Syst. Biol. 42 182–192. 10.1093/sysbio/42.2.182 Huelsenbeck J. P. Ronquist F. (2001). MRBAYES: bayesian inference of phylogenetic trees. Bioinformatics 17 754–755. 10.1093/bioinformatics/17.8.754 11524383 Hyde K. D. Fröhlich J. Taylor J. E. (1998). Fungi from palms. XXXVI. Reflections on unitunicate ascomycetes with apiospores. Sydowia 50 21–80. Hyde K. D. Norphanphoun C. Maharachchikumbura S. S. N. Bhat D. J. Jones E. B. G. Bundhun D. (2020). Refined families of Sordariomycetes. Mycosphere 11 305–1059. 10.5943/mycosphere/11/1/7 Hyde K. D. Zhou D. Dalisayl T. (2002a). Bambusicolous fungi: a review. Fung. Divers. 9 1–14. Hyde K. D. Zhou D. McKenzie E. Ho W. Dalisay T. (2002b). Vertical distribution of saprobic fungi on bamboo culms. Fungal Divers. 11 109–118. Jayasiri C. S. Hyde K. D. Ariyawansa H. A. Bhat J. Buyck B. Cai L. (2015). The faces of fungi database: fungal names linked with morphology, phylogeny and human impacts. Fungal Divers. 74 3–18. 10.1007/s13225-015-0351-8 Jiang H. B. Hyde K. D. Doilom M. Karunarathna S. C. Xu J. C. Phookamsak R. (2019). Arthrinium setostromum (Apiosporaceae, Xylariales), a novel species associated with dead bamboo from Yunnan, China. Asia. J. Mycol. 2 254–268. 10.5943/ajom/2/1/16 Jiang N. Li J. Tian C. M. (2018). Arthrinium species associated with bamboo and reed plants in China. Fungal Syst. Evol. 2 1–9. 10.3114/fuse.2018.02.01 32467884 Jiang N. Liang Y. M. Tian C. M. (2020). A novel bambusicolous fungus from China, Arthrinium chinense (Xylariales). Sydowia 72 77–83. 10.12905/0380 Katoh K. Standley D. M. (2013). MAFFT multiple sequence alignment software version 7: improvements in performance and usability. Mol. Biol. Evol. 30 772–780. 10.1093/molbev/mst010 23329690 Kelchner S. A., and Bamboo Phylogeny Group (2013). Higher level phylogenetic relationships within the bamboos (Poaceae: Bambusoideae) based on five plastid markers. Mol. Phylogenet. Evol. 67 404–413. 10.1016/j.ympev.2013.02.005 23454093 Li B. J. Liu P. Q. Jiang Y. Weng Q. Y. Chen Q. H. (2016). First report of culm rot caused by Arthrinium phaeospermum on Phyllostachys viridis in China. Plant Dis. 100 1013–1013. 10.1094/PDIS-08-15-0901-PDN Liu J. K. Chomnunti P. Cai L. Phookamsak R. Chukeatirote E. Jones E. B. G. (2010). Phylogeny and morphology of Neodeightonia palmicola sp. nov. from palms. Sydowia 62 261–276. Liu N. G. Bhat D. J. Hyde K. D. Liu J. K. (2019). Conioscypha tenebrosa sp. nov. (Conioscyphaceae) from China and notes on Conioscypha species. Phytotaxa 413 159–171. 10.11646/phytotaxa.413.2.5 Luo Z. Hyde K. D. Liu J. K. Maharachchikumbura S. S. N. Jeewon R. Bao D. F. (2019). Freshwater Sordariomycetes. Fungal Divers. 99 451–660. 10.1007/s13225-019-00438-1 Mapook A. Hyde K. D. McKenzie E. H. C. Gareth J. E. B. Bhat D. J. Jeewon R. (2020). Taxonomic and phylogenetic contributions to fungi associated with the invasive weed Chromolaena odorata (Siam weed). Fungal Divers. 101 1–175. 10.1007/s13225-020-00444-8 Martínez-Cano C. Grey W. E. Sands D. C. (1992). First report of Arthrinium arundinis causing kernel blight on barley. Plant Dis. 76 1077. 10.1094/PD-76-1077B Mavragani D. C. Abdellatif L. McConkey B. Hamel C. Vujanovic V. (2007). First report of damping-off of durum wheat caused by Arthrinium sacchari in the semi-arid Saskatchewan fields. Plant Dis. 91:469. 10.1094/pdis-91-4-0469a 30781220 Nylander J. A. A. (2004). MrModeltest v2. Program Distributed by the Author. Uppsala: Evolutionary Biology Centre, Uppsala University. O’Donnell K. Cigelnik E. (1997). Two divergent intragenomic rDNA ITS2 types within a monophyletic lineage of the fungus Fusarium are nonorthologous. Mol. Phylogenet. Evol. 7 103–116. 10.1006/mpev.1996.0376 9007025 O’Donnell K. Kistler H. C. Cigelnik E. Ploetz R. C. (1998). Multiple evolutionary origins of the fungus causing Panama disease of banana: concordant evidence from nuclear and mitochondrial gene genealogies. Proc. Natl. Acad. Sci. U.S.A. 95 2044–2049. 10.1073/pnas.95.5.2044 9482835 Pintos A. Alvarado P. Planas J. Jarling R. (2019). Six new species of Arthrinium from Europe and notes about A. caricicola and other species found in Carex spp. Hosts. Mycokeys 49 15–48. 10.3897/mycokeys.49.32115 30918449 Rai M. K. (1989). Mycosis in man due to Arthrinium phaeospermum var. indicum. First case report. Mycoses 32 472–475. 10.1111/j.1439-0507.1989.tb02285.x 2608094 Rambaut A. (2012). ). FigTree, Version 1.4. 2. Edinburgh: University of Edinburgh. Rannala B. Yang Z. (1996). Probability distribution of molecular evolutionary trees: a new method of phylogenetic inference. J. Mol. Evol. 43 304–311. 10.1007/BF02338839 8703097 Seifert K. Morgan-Jones G. Gams W. Kendrick B. (2011). The Genera of Hyphomycetes.[CBS Biodiversity Series 9]. Utrecht: CBS-KNAW Fungal Biodiversity Centre. Senanayake I. C. Bhat J. D. Cheewangkoon R. Xie N. (2020a). Bambusicolous Arthrinium species in guangdong province. China. Front. Microbiol. 11:602773. 10.3389/fmicb.2020.602773 33381097 Senanayake I. C. Maharachchikumbura S. S. Hyde K. D. Bhat J. D. Jones E. G. McKenzie E. H. (2015). Towards unraveling relationships in Xylariomycetidae (Sordariomycetes). Fungal Divers. 73 73–144. 10.1007/s13225-015-0340-y Senanayake I. C. Rathnayake A. R. Marasinghe D. S. Calabon M. S. Gentekaki E. Lee H. B. (2020b). Morphological approaches in studying fungi: collection, examination, isolation, sporulation and preservation. Mycosphere 11 2678–2754. 10.5943/mycosphere/11/1/20 Sharma R. Kulkarni G. Sonawane M. S. Shouche Y. S. (2014). A new endophytic species of Arthrinium (Apiosporaceae) from Jatropha podagrica. Mycoscience 55 118–123. 10.1016/j.myc.2013.06.004 Silvestro D. Michalak I. (2012). raxmlGUI: a graphical front-end for RAxML. Org. Divers. Evol. 12 335–337. 10.1007/s13127-011-0056-0 Swofford D. L. (2002). PAUP∗: Phylogenetic Analysis Using Parsimony (∗and Other Methods). Version 4. Sunderland, MA: Sinauer Associates. Tang X. Goonasekara I. D. Jayawardena R. S. Jiang H. B. Li J. F. Hyde K. D. (2020). Arthrinium bambusicola (Fungi, Sordariomycetes), a new species from Schizostachyum brachycladum in northern Thailand. Biodivers. Data J. 8:e58755. 10.3897/BDJ.8.e58755 33364897 Vilgalys R. Hester M. (1990). Rapid genetic identification and mapping of enzymatically amplified ribosomal DNA from several Cryptococcus species. J. Bacteriol. 172 4238–4246. 10.1128/jb.172.8.4238-4246.1990 2376561 Wang M. Tan X. M. Liu F. Cai L. (2018). Eight new Arthrinium species from China. MycoKeys 34 1–24. 10.3897/mycokeys.34.24221 29755262 Wijayawardene N. N. Hyde K. D. Rajeshkumar K. C. Hawksworth D. L. Madrid H. Kirk P. M. (2017). Notes for genera: ascomycota. Fungal Divers. 86 1–594. 10.1007/s13225-017-0386-0 Wijesinghe S. N. Wang Y. Camporesi E. Wanasinghe D. N. Boonmee S. Hyde K. D. (2020). A new genus of Bambusicolaceae (Pleosporales) on Corylus avellana (Fagales) from Italy. Biodivers. Data J. 8:e55957. 10.3897/BDJ.8.e55957 32904352 Yan H. Jiang N. Liang L. Y. Yang Q. Tian C. M. (2019). Arthrinium trachycarpum sp. nov. from Trachycarpus fortunei in China. Phytotaxa 400 203–210. 10.11646/phytotaxa.400.3.7 Yang C. L. Xu X. L. Dong W. Wanasinghe D. N. Liu Y. G. Hyde K. D. (2019). Introducing Arthrinium phyllostachium sp. nov. (Apiosporaceae, Xylariales) on Phyllostachys heteroclada from Sichuan Province, China. Phytotaxa 406 091–110. 10.1127/nova_hedwigia/2019/0526 Zhang J. F. Liu J. K. Hyde K. D. Chen Y. Y. Liu Y. X. Liu Z. Y. (2017). Two new species of Dyfrolomyces (Dyfrolomycetaceae, Dothideomycetes) from karst landforms. Phytotaxa 313:267. 10.11646/phytotaxa.313.3.4 Zhang J. F. Liu J. K. Jeewon R. Wanasinghe D. N. Liu Z. Y. (2019). Fungi from Asian Karst formations III. Molecular and morphological characterization reveal new taxa in Phaeosphaeriaceae. Mycosphere 10 202–220. 10.5943/mycosphere/10/1/3 Zhao Y. M. Deng C. R. Chen X. (1990). Arthrinium phaeospermum causing dermatomycosis, a new record of China. Acta Mycol. Sin. 9 232–235. Zhao Y. Z. Zhang Z. F. Cai L. Peng W. J. Liu F. (2018). Four new filamentous fungal species from newly-collected and hivestored bee pollen. Mycosphere 9 1089–1116. 10.5943/mycosphere/9/6/3 33332223 Zhaxybayeva O. Gogarten J. P. (2002). Bootstrap, Bayesian probability and maximum likelihood mapping: exploring new tools for comparative genome analyses. BMC Genom. 3:4. 10.1186/1471-2164-3-4 11918828

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