Morpho-phylogenetic evidence reveals novel Bambusicolous fungi from Guizhou Province, China

Abstract

Figures

Phylogram generated from maximum likelihood analysis based on a combined dataset of SSU, ITS, LSU, rpb2 and tef1-α sequences. Bootstrap support values for ML (≥75%) and bayesian posterior probabilities (≥0.95) are given at the nodes (ML BS/PP). Branches with 100% ML BS and 1.00 PP are thickened. New strains are shown in red. The tree is rooted with Sulcatisporaberchemiae KT1607 and Sulcatisporaacerina KT2982, and ex-type strains are in bold.

Bambusicolaellipsospora (HKAS 112592, holotype) A, B appearance of ascomata on the host C vertical section of an ascoma D peridium E pseudoparaphyses F, G cultures on PDAF from above G from below H–L asci M–Q ascospores. Scale bars: 100 µm (C); 10 µm (D, E, M–Q); 20 µm (H–L).

Bambusicolagelatinosospora (HKAS 112599, holotype) A, B appearance of ascomata on the host C vertical section of an ascoma D pseudoparaphyses E germinated ascospores F, G cultures on PDAF from above G from below H–L asci M–Q ascospores. Scale bars:100 µm (C); 30 µm (E); 20 µm (H–L); 15 µm (D, M–Q).

Bambusicolapseudodimorphae (HKAS 112597, holotype) A, B conidiomata on the host C vertical section of a conidioma D germinated conidium E, F cultures on PDAE from above F from below G−K conidiogenous cells and developing conidia L−P conidia. Scale bars: 100 µm (C); 20 µm (D); 5 µm (G−I); 10 µm (J−P).

Reproduced Bambusicolapseudodimorphae (CGMCC 3.20353, ex-type) A, B colony on PDAC−F conidiogenous cells with conidia G−J macroconidia K microconidia. Scale bars: 10 µm (C−K).

Bambusicolaautumnalis (HKAS 112598) A, B appearance of ascomata on the host C pseudoparaphyses D vertical section of an ascoma E peridium F germinated ascospore G, H cultures on PDAG from above H from below I–M asci N–R ascospores. Scale bars: 100 µm (D); 25 µm (E, F); 20 µm (I–M); 15 µm (C, N–R).

Reproduced Bambusicolaautumnalis (CGMCC 3.20354) A, B colony on PDAC−F conidiogenous cells with macroconidia G−K macroconidia L−N conidiogenous cells with microconidia O microconidia. Scale bars: 10 µm (C−O).

Corylicolaitalica (GZAAS 21-0243) A, B appearance of ascomata on host C vertical section of an ascoma D peridium E germinated ascospore F pseudoparaphyses G−J asci K−N ascospores. Scale bars: 50 µm (C); 10 µm (D−J); 5 µm (K−N).

Tables

Table 1.. Isolates used in this study.

Taxa	Vouchers/Strains	GenBank accession numbers
		SSU	ITS	LSU	rpb2	tef1-α
Bambusicolaaquatica	MFLUCC 18-1031T	MT864293	MT627729	MN913710	MT878462	MT954392
Bambusicolaautumnalis	CGMCC 3.24280T	OQ427823	OQ427824	OQ427825	OQ507621	OQ507622
Bambusicolaautumnalis	CGMCC 3.20354	OR853568	OR853544	OR853556	PP084027	PP111465
Bambusicolaautumnalis	GZCC 21-0897	OR853569	OR853545	OR853557	PP084028	PP111466
Bambusicolabambusae	MFLUCC 11-0614T	JX442039	JX442031	JX442035	KP761718	KP761722
Bambusicoladidymospora	MFLUCC 10-0557T	KU872110	KU940116	KU863105	KU940163	KU940188
Bambusicoladimorpha	MFLUCC 13-0282T	KY038354	KY026582	KY000661	KY056663	N/A
Bambusicolaellipsospora	CGMCC 3.20243T	OR853572	OR853548	OR853560	PP084031	PP111469
Bambusicolaellipsospora	GZCC 21-899	OR853573	OR853549	OR853561	PP084032	PP111470
Bambusicolaficuum	MFLUCC 17-0872T	MT215581	N/A	MT215580	N/A	MT199326
Bambusicolafusispora	MFLUCC 20-0149T	MW076529	MW076532	MW076531	MW034589	N/A
Bambusicolagelatinosospora	CGMCC 3.20355T	OR853570	OR853546	OR853558	PP084029	PP111467
Bambusicolagelatinosospora	GZCC 21-0898	OR853571	OR853547	OR853559	PP084030	PP111468
Bambusicolaguttulata	CGMCC 3.20935T	ON332919	ON332909	ON332927	ON383985	ON381177
Bambusicolahongheensis	KUN-HKAS 129042T	OR501419	OR233600	OR335804	OR540736	N/A
Bambusicolairregulispora	MFLUCC 11-0437T	JX442040	JX442032	JX442036	KP761719	KP761723
Bambusicolaloculata	MFLUCC 13-0856T	KP761735	KP761732	KP761729	KP761715	KP761724
Bambusicolamassarinia	MFLUCC 11-0389T	JX442041	JX442033	JX442037	KP761716	KP761725
Bambusicolameishanensis	CGMCC 3.25594T	PQ066540	PQ067775	PQ067690	N/A	PQ278548
Bambusicolananensis	MFLUCC 21-0063T	N/A	OK491656	OK491652	N/A	N/A
Bambusicolapseudodimorphae	CGMCC 3.20353T	OR853566	OR853542	OR853554	PP084025	PP111463
Bambusicolapseudodimorphae	GZCC 21-0896	OR853567	OR853543	OR853555	PP084026	PP111464
Bambusicolapustulata	MFLUCC 15-0190T	KU872112	KU940118	KU863107	KU940165	KU940190
Bambusicolasichuanensis	SICAUCC 16-0002T	MK253528	MK253473	MK253532	MK262830	MK262828
Bambusicolasplendida	MFLUCC 11-0439T	JX442042	JX442034	JX442038	KP761717	KP761726
Bambusicolasubthailandica	SICAUCC 16-0005T	MK253529	MK253474	MK253533	MK262831	MK262829
Bambusicolathailandica	MFLUCC 11-0147T	N/A	KU940119	KU863108	KU940166	KU940191
Bambusicolatriseptatispora	MFLUCC 11-0166T	N/A	KU940120	KU863109	KU940167	N/A
Corylicolaitalica	MFLUCC 19-0500	MT554923	MT554925	MT554926	MT590776	N/A
Corylicolaitalica	MFLUCC 20-0111T	MT633084	MT633085	MT626713	MT635596	MT590777
Corylicolaitalica	GZCC 21-0757	PQ571780	PQ571751	PQ571778	N/A	PQ591923
Leucaenicolaaseptata	MFLUCC 17-2423T	MK347853	MK347746	MK347963	MK434891	MK360059
Leucaenicolacamelliae	NTUCC 18-093-4T	MT071229	MT112302	MT071278	MT743283	MT374091
Leucaenicolaosmanthi	NTUCC 18-101-1T	MN908609	MN908565	MN908612	MN915020	MN918596
Leucaenicolaphraeana	MFLUCC 18-0472T	MK347892	N/A	MK348003	MK434867	MK360060
Leucaenicolataiwanensis	NTUCC 18-094-1T	MT071228	MT112301	MT071277	N/A	N/A
Neopalmiascomamacadamiae	ZHKUCC 23-0746T	OR978323	OR978321	OR978582	OR983253	OR999080
Neopalmiascomamacadamiae	ZHKUCC 23-0747	OR978324	OR978322	OR978583	OR983254	OR999081
Palmiascomagregariascomum	MFLUCC 11-0175T	KP753958	KP744452	KP744495	KP998466	N/A
Palmiascomaqujingense	KUMCC 19-0201T	MT477186	MT477183	MT477185	MT495782	N/A
Sulcatisporaacerina	KT2982	LC014605	LC014597	LC014610	N/A	LC014615
Sulcatisporaberchemiae	KT1607	AB797244	AB809635	AB807534	N/A	AB808509

Table 2.. Morphological comparisons of Bambusicolagelatinosospora and similar taxa within Bambusicolaceae.

Morphological characteristics	Bambusicolagelatinosospora (In this study)	Bambusicolathailandica (Dai et al. 2017)	Bambusicolasubthailandica (Yang et al. 2019)
Ascomata	320–345 μm diam.; 170–230 μm high	310–400 μm diam.; 90–155 μm high	326–377 μm diam.; 226–277 μm high
Asci	60–90 × 10–12 μm; (x̄ = 77 × 11 μm, n = 20)	(60–)70– 90(−97) × 10–12(−14) μm; (x̄ = 75.5 × 12 μm, n = 20)	(48–)65–86(–119) × (7.5–)9–12 μm; (x̄ = 75.6 × 11 μm, n = 40)
Ascospores	(16–)20–25 × 4–6 μm; (x̄ = 22 × 5 μm, n = 30)	(16–)18– 22(−24) × (3.5–)4–6 μm; (x̄ = 2 0.8 × 5 μm, n = 30)	(20–)21–24(–26) × (4–)5–6(–6.5) μm; (x̄ = 22.6 × 5.7 μm, n = 50)
Culture colour	white, reverse pale yellow	white to cream	grey to grey brown
Culture texture	felted, with white dense mycelium on the surface	fluffy to floccose	fluffy

Full text

Introduction

Bambusoideae, a subfamily of Poaceae, exhibits remarkable species diversity (Shi et al. 2020). As a dominant group within this subfamily, bamboos provide substantial economic, ecological, and social benefits, making them an essential resource in modern forestry and regional economies (Lobovikov et al. 2007; Shukla et al. 2016). Fungi associated with bamboo, collectively called bambusicolous fungi, inhabit various bamboo tissues (Hino 1938; Hyde et al. 2002). These fungi include pathogens that compromise bamboo health (Kuai 1996), endophytes that promote growth and enhance stress resistance (Yan et al. 2023), and saprobes that facilitate organic matter decomposition, nutrient cycling, and energy transformation within bamboo ecosystems (Senanayake et al. 2020; Feng et al. 2021; Jiang et al. 2021, 2022; Liang et al. 2023; Zhang et al. 2023; Yu et al. 2024). With increasing research on bambusicolous fungi, numerous new species continue to be reported (Kwon et al. 2022; Jiang et al. 2022; Yang et al. 2023; Yu et al. 2024).

The family Bambusicolaceae was established by Hyde et al. (2013) to accommodate the type genus Bambusicola based on comprehensive morphological and molecular evidence. Subsequent studies expanded the family to include additional genera, such as Leucaenicola, Longipedicellata, Neobambusicola, and Palmiascoma (Crous et al. 2014; Liu et al. 2015; Jayasiri et al. 2019). However, Neobambusicola and Longipedicellata were later transferred to Sulcatisporaceae and Longipedicellataceae, respectively, following detailed morphological and phylogenetic analysis (Tanaka et al. 2015; Phukhamsakda et al. 2016). More recently, the genera Corylicola, Flavosporella, and Neopalmiascoma have been incorporated into Bambusicolaceae (Wijesinghe et al. 2020; Yu et al. 2024; Zhang et al. 2024), bringing the current number of recognized genera to six: Bambusicola, Corylicola, Flavosporella, Leucaenicola, Neopalmiascoma, and Palmiascoma. Among these, Bambusicola remains the largest and most extensively studied genus. It is morphologically characterized by uni-to multi-loculate, immersed ascomata, bitunicate, cylindrical asci with a short furcate pedicel and a shallow apical ocular chamber and 2–3-seriate, slightly broad-fusiform, 1-septate hyaline ascospores, surrounded by a gelatinous sheath (Dai et al. 2012, 2017; Hyde et al. 2013; Liu et al. 2015). Its asexual morphs exhibit indistinct conidiophores, holoblastic, annelidic, discrete, cylindrical conidiogenous cells, and pale brown to dark brown, 1–3-septate, cylindrical conidia (Dai et al. 2012, 2017; Hyde et al. 2013; Liu et al. 2015; Jayasiri et al. 2019).

Given the increasing recognition of bambusicolous fungal diversity, our study aimed to explore the microfungi associated with decaying bamboo in Guizhou, China. As a result, we identified five species belonging to Bambusicolaceae. To resolve their taxonomic placement and phylogenetic relationships, we conducted morphological comparisons and multi-gene phylogenetic analyses using a concatenated dataset of SSU, ITS, LSU, rpb2, and tef1-α sequences. Our findings revealed three novel species: Bambusicolapseudodimorphae, B.gelatinosospora, and B.ellipsospora. Additionally, we have also identified two known species, namely Bambusicolaautumnalis and Corylicolaitalica. Notably, this study represents the first report of the asexual morph of B.autumnalis, and C.italica is newly recorded from China. We provide comprehensive morphological descriptions, illustrations, and molecular phylogenetic insights, contributing to the growing understanding of bambusicolous fungi.

Materials and methods

Sample collection, morphological studies, and isolation

Decayed culms were collected from Guizhou Province, China. Fungal fruiting bodies were examined using a stereomicroscope (Motic SMZ 168). Freehand sections of ascomata and other fungal structures were mounted in water for microscopic studies and photomicrography. Morphological observations were made using a Nikon ECLIPSE Ni compound microscope fitted with a Nikon DS-Ri2 digital camera. All measurements were made with Tarosoft Image FrameWork software (IFW) (Liu et al. 2010). Photo plates were processed with Adobe Photoshop CS6 software (Adobe Systems, USA). Single spore isolations were carried out following the method in Chomnunti et al. (2014). Type specimens were deposited in the herbarium of Cryptogams Kunming Institute of Botany Academia Sinica (HKAS), Kunming, China, and herbarium of Guizhou Academy of Agriculture sciences (GZAAS), Guiyang, China. Pure cultures were deposited in China General Microbiological Culture Collection Center (CGMCC), Beijing, China, and Guizhou Culture Collection (GZCC), Guiyang, China. Facesoffungi (http://www.facesoffungi.org/) numbers were obtained as in Jayasiri et al. (2015). The new species are registered in Index Fungorum (2025, http://www.indexfungorum.org/).

DNA extraction, PCR amplification and sequencing

Fungal mycelia were scraped from the pure culture which was growing on PDA (Potato Dextrose Agar) for one week at 25 °C in the dark. The total genomic DNA was extracted using an Ezup Column Fungi Genomic DNA Purification Kit (Sangon Biotech, China) from fresh fungal mycelia. Five gene regions, small subunit rDNA (SSU), internal transcribed spacer (ITS), large subunit rDNA (LSU), RNA polymerase II subunit 2 (rpb2) and translation elongation factor 1-alpha (tef1-α) were amplified using the primer pairs NS1/NS4 (White et al. 1990), ITS4/ITS5, LR0R/LR5 (Vilgalys and Hester 1990), fRPB2-5f /fRPB2-7cR (Liu et al. 1999) and ef1-983F/ef1-2218R (Rehner and Buckley 2005), respectively. Polymerase chain reaction (PCR) was carried out in a 25 μL reaction volume containing 12.5 μL 2 × PCR Master Mix (Sangon Biotech, China), 9.5 μL ddH_2_O, 1 μL of each primer and 1 μL DNA template. The amplification conditions for SSU, ITS, LSU and tef1-α gene regions followed Tennakoon et al. (2016), for rpb2 gene regions followed Du et al. (2024). PCR products were examined using 1.2% agarose electrophoresis gel stained with ethidium bromide and sequenced by Sangon Biotech (Shanghai) Co., Ltd, China. Newly generated nucleotide sequences were submitted in GenBank (Table 1).

Phylogenetic analyses

Analyses of Bambusicolaceae were performed respectively. Both phylogenetic analyses were performed based on SSU, ITS, LSU, rpb2 and tef1-α sequence data. The representative strains of Bambusicolaceae (Table 1) were referred to BLAST (https://blast.ncbi.nlm.nih.gov/Blast.cgi) results and relevant publications (Yu et al. 2022, 2024; Liang et al. 2023; Zhang et al. 2024). Sequences were aligned using MAFFT v. 7 (Katoh and Standley 2013). Manual adjustments were performed when necessary using BioEdit v. 7.0 (Hall 1999). Phylogenetic analyses of maximum likelihood (ML) and bayesian inference (BI) were carried out as detailed in Dissanayake et al. (2020) and performed with raxmlGUI v. 1.3 (Silvestro and Michalak 2012) and MrBayes v3.1. (Huelsenbeck and Ronquist 2001; Zhaxybayeva and Gogarten 2002; Nylander 2004). Phylogenetic trees were visualized with FigTree v1.4.2 (Rambaut 2012) and edited using Adobe Illustrator 2021 (2.6.0.44) and Adobe Photoshop CS6 software (Adobe Systems, USA).

Results

Phylogeny

To determine the phylogenetic placements of the new collections in this study, the combined SSU, ITS, LSU, rpb2 and tef1-α data sets, comprising 42 taxa with Sulcatisporaberchemiae KT1607 and Sulcatisporaacerina KT2982 as the outgroup taxa. The dataset comprises 4, 641 characters (SSU: 1-1001; ITS: 1002-1896; LSU: 1897-2701; rpb2: 2702-3691; tef1-α: 3692-4641) after alignment, including gaps. Maximum likelihood and bayesian analyses were performed, respectively, and both methods yielded consistent topologies. The best-scoring RAxML tree (Fig. 1) was obtained with a final likelihood value of -23443.659740. Estimated base frequencies were as follows: A = 0.243090, C = 0.252645, G = 0.271896, T = 0.228350; substitution rates AC = 1.173578, AG = 2.804498, AT = 0.917016, CG = 1.080920, CT = 5.912507, GT = 1.000000; The gamma distribution shape parameter alpha is equal to 0.305487 and the Tree-Length equal to 0.166660.

Phylogram generated from maximum likelihood analysis based on a combined dataset of SSU, ITS, LSU, rpb2 and tef1-α sequences. Bootstrap support values for ML (≥75%) and bayesian posterior probabilities (≥0.95) are given at the nodes (ML BS/PP). Branches with 100% ML BS and 1.00 PP are thickened. New strains are shown in red. The tree is rooted with Sulcatisporaberchemiae KT1607 and Sulcatisporaacerina KT2982, and ex-type strains are in bold.

Phylogenetic analyses showed that the nine newly obtained strains of Bambusicolaceae clustered into five clades and can be recognized as three new species (Bambusicolaellipsospora, B.gelatinosospora, B.pseudodimorphae) and two known species (B.autumnalis, Corylicolaitalica) (Fig. 1).

Taxonomy

Bambusicola

ellipsospora

Taxon classificationFungiPleosporalesBambusicolaceae



Y. Feng, Z.Y. Liu & Jian K. Liu sp. nov.

DFB58706-5BD2-5D60-8A27-987323760EF0

Index Fungorum: IF903223

Facesoffungi Number: FoF15907

Fig. 2

Holotype.

HKAS 112592.

Etymology.

The epithet refers to the ellipsoidal ascospores.

Description.

Saprobic on dead bamboo culms. Sexual morph: Ascomata 215–363 μm diam., 180–288 μm high, solitary, scattered to gregarious, immersed to erumpent, later becoming superficial, forming brown to dark brown, lenticular spots on the host surface with a slit. Peridium comprising several layers of cells of textura angularis, inner layers comprising hyaline to dark brown, outer layers composed of thick, dark brown to black cells. Hamathecium of dense, 0.5–1.8 μm wide, filamentous, branched, septate, smooth-walled, trabecular pseudoparaphyses, anastomosing at the apex, embedded in a hyaline, gelatinous matrix. Asci 70–92 × 15–21 μm (x̄ = 82 × 17 μm, n = 20), 8-spored, bitunicate, fissitunicate, broadly cylindrical to cylindri-clavate, with a short pedicel, apically rounded with a well-developed ocular chamber. Ascospores (18–)19–24(–25) × (5–)6–8(–9) μm (x̄ = 22 × 7 μm, n = 30), overlapping, biseriate, hyaline, straight, ellipsoidal to fusiform, with obtuse ends, 1-septate, constricted at the septum, smooth-walled with 4 large guttules, surrounded by a thin-gelatinous sheath. Asexual morph: Undetermined.

Bambusicolaellipsospora (HKAS 112592, holotype) A, B appearance of ascomata on the host C vertical section of an ascoma D peridium E pseudoparaphyses F, G cultures on PDAF from above G from below H–L asci M–Q ascospores. Scale bars: 100 µm (C); 10 µm (D, E, M–Q); 20 µm (H–L).

Culture characteristics.

Ascospores germinating on PDA within 12 h. Colonies on PDA slow growing, 13 mm diam. after 10 d at 25 °C in the dark, circular, white, velvety, with dense mycelium on the surface; in reverse brown in the center, becoming paler to white at the entire margin.

Material examined.

China • Guizhou Province, Chishui City. On dead culms of bamboo, 10 July 2019, Yao Feng CS018 (HKAS 112592, holotype; GZAAS 21-0503, isotype), ex-type living cultures CGMCC 3.20356 = GZCC 21-0803; ibid., CS036 (GZAAS 21-0391, paratype), living culture GZCC 21-899.

Notes.

Phylogenetic analyses revealed that the two strains of Bambusicolaellipsospora (CGMCC 3.20356 and GZCC 21-0899) formed a distinct clade, sister to B.autumnalis (CGMCC 3.24280, CGMCC 3.20354, GZCC 21-0897) (Fig. 1). Bambusicolaellipsospora can be distinguished from B.autumnalis based on sequence divergence in tef1-α (874/927 bp) and rpb2 (699/784 bp). Additionally, morphological differences further support their distinction, as B.ellipsospora produces ellipsoidal to fusiform ascospores with obtuse rounded ends, while B.autumnalis has fusiform and slightly curved ascospores with narrower acute ends (Liang et al. 2023). Moreover, the ascospore of B.ellipsospora collected in this study shows distinct constriction at the septum, whereas that of B.autumnalis only has slight constriction. Based on morphological and phylogenetic evidence, B.ellipsospora is recognized as a novel species.

Bambusicola

gelatinosospora

Taxon classificationFungiPleosporalesBambusicolaceae



Y. Feng, Z.Y. Liu & Jian K. Liu sp. nov.

35975FA1-8AEE-5A35-8D46-F6C6ABB14D31

Index Fungorum: IF903224

Facesoffungi Number: FoF15908

Fig. 3

Holotype.

HKAS 112599.

Etymology.

The epithet refers to the gelatinous sheath of ascospores.

Description.

Saprobic on dead bamboo culms, forming raised, black spots on the host surface. Sexual morph: Ascomata 320–345 μm diam, 170–230 μm high, solitary, scattered to gregarious, immersed, subglobose with a flattened base. Peridium comprising several layers of cells of textura angularis, less distinguished from the host tissue. Hamathecium of dense, 1–2 μm wide, filamentous, branched, septate, smooth-walled, trabecular pseudoparaphyses, anastomosing at the apex, embedded in a hyaline, gelatinous matrix. Asci 60–90 × 10–12 μm (x̄ = 77 × 11 μm, n = 20), 8-spored, bitunicate, fissitunicate, broadly cylindrical to cylindrical-clavate, with a short pedicel, apically rounded with a well-developed ocular chamber. Ascospores (16–)20–25 × 4–6 μm (x̄ = 22 × 5 μm, n = 30), overlapping, biseriate, hyaline, fusiform, slightly bent with acute ends, 3-septate, slightly constricted at the septa, smooth-walled, guttulate, surrounded by a gelatinous sheath. Asexual morph: Undetermined.

Bambusicolagelatinosospora (HKAS 112599, holotype) A, B appearance of ascomata on the host C vertical section of an ascoma D pseudoparaphyses E germinated ascospores F, G cultures on PDAF from above G from below H–L asci M–Q ascospores. Scale bars:100 µm (C); 30 µm (E); 20 µm (H–L); 15 µm (D, M–Q).

Culture characteristics.

Colonies on PDA slow growing, reaching 15 mm diam. after 10 d at 25 °C in dark. circular, felted, with white dense mycelium on the surface. In reverse pale yellow, becoming brown from the center, with an entire margin.

Material examined.

China • Guizhou Province, Xingyi City. On dead stem of bamboo, 5 September 2019, Yao Feng, XY19-11 (HKAS 112599, holotype; GZAAS 21-0502, isotype), ex-type living cultures CGMCC 3.20355 = GZCC 21-0802; ibid., on dead branches on bamboo, 5 September 2019, Yao Feng, XY19a (GZAAS 21-0390; paratype), living cultures GZCC21-0898.

Notes.

Phylogenetic analyses revealed that the two strains of Bambusicolagelatinosospora (CGMCC 3.20355 and GZCC 21-0898) clustered with B.thailandica (MFLUCC 11-0147) and B.subthailandica (SICAUCC 16-0005) as a distinct lineage (Fig. 1). Morphologically, B.gelatinosospora closely resembles B.thailandica and B.subthailandica, sharing key characteristics such as ostiolate ascomata, cylindrical to cylindri-clavate asci, and hyaline, fusiform, 3-septate ascospores with acute ends (Dai et al. 2017; Yang et al. 2019). Although these species are morphologically indistinguishable, their cultures exhibit differences in colors and colony morphology (Table 2). Additionally, they can be differentiated by their minimal sequence similarities. In a comparison of ITS, LSU, rpb2 and tef1-α nucleotides, B.gelatinosospora (CGMCC 3.20355) has 98%, 99%, 97% and 99% similarity, in ITS (702/713 bp, 1 gap), LSU (817/819 bp, no gaps), rpb2 (949/974 bp, no gaps), and tef1-α (914/920 bp, no gap), which is different from B.thailandica (MFLUCC 11-0147). These findings combined with its morphological and molecular distinctiveness strongly supported the conclusion that Bambusicolagelatinosospora represents a new species within the genus Bambusicola.

Bambusicola

pseudodimorphae

Taxon classificationFungiPleosporalesBambusicolaceae



Y. Feng, Z.Y. Liu & Jian K. Liu sp. nov.

AB9367A4-1559-5985-A9C9-E75214A6AA8B

Index Fungorum: IF903225

Facesoffungi Number: FoF15909

Figs 4 , 5

Holotype.

HKAS 112597.

Etymology.

Species epithet refers to the similar conidia to Bambusicoladimorpha which have two types in culture.

Description.

Saprobic on bamboo culms. Sexual morph: Undetermined. Asexual morph: Conidiomata initially embedded in the epidermis of bamboo culms and later breaking through the epidermis,solitary to gregarious, subglobose with a flattened base, brown to dark brown. 78–161 μm high, 180–270 μm diam. Conidiomatal wall comprising 3–5 layers of cells of textura angularis, with dark brown outer layers and hyaline inner layers, less distinguished from the host tissue. Conidiophores reduced to conidiogenous cells. Conidiogenous cells 9–32 × 1–2 μm (x̄ = 23 × 2 μm, n = 15), holoblastic, monoblastic, cylindrical, smooth, hyaline. Conidia 24–27 × 3–4 μm (x̄ = 26 × 4 μm, n = 30), initially hyaline to pale brown, aseptate, becoming yellowish brown, 2–3-septate when maturity, cylindrical, obtuse at both ends, smooth-walled, straight, guttulate.

Bambusicolapseudodimorphae (HKAS 112597, holotype) A, B conidiomata on the host C vertical section of a conidioma D germinated conidium E, F cultures on PDAE from above F from below G−K conidiogenous cells and developing conidia L−P conidia. Scale bars: 100 µm (C); 20 µm (D); 5 µm (G−I); 10 µm (J−P).

Culture characteristics.

Colonies on PDA slow growing, 16 mm diam. after 10 d at 25 °C in dark, circular, with an entire margin, white, fluffy, with dense mycelium on the surface. Reverse white with a yellowish center. After being cultivated on PDA for two months, Bambusicolapseudodimorphae generated two types of conidia, macro- and microconidia. Macroconidia 20–26(–29) × 3–5 μm (x̄ = 24 × 4 μm, n = 30), cylindrical, with obtuse and rounded ends, 3-septate, pale brown to brown, smooth-walled. Microconidia 3–4 × 1–3 μm (x̄ = 4 × 2 μm, n = 30), ellipsoidal, pale brown, aseptate.

Reproduced Bambusicolapseudodimorphae (CGMCC 3.20353, ex-type) A, B colony on PDAC−F conidiogenous cells with conidia G−J macroconidia K microconidia. Scale bars: 10 µm (C−K).

Material examined.

China • Guizhou Province, Xingyi City. On dead bamboo stems, 5 September 2019, Yao Feng, XY19-3 (HKAS 112597, holotype; GZAAS 21-0501, isotype), ex-type living cultures CGMCC 3.20353 = GZCC21-0801; ibid., 6 September 2019, Yao Feng, XY19b (GZAAS 21-0388, paratype), living culture GZCC 21-0896.

Notes.

Phylogenetic analyses revealed that the two strains of Bambusicolapseudodimorphae clustered with B.bambusae, B.dimorpha, B.ficuum, and B.pustulata, forming a distinct lineage within Bambusicola (Fig. 1). Morphologically, B.pseudodimorphae closely resembles is similar to B.dimorpha in having two types of conidia. However, B.pseudodimorphae differs by having smaller conidiomata (78–161 × 180–270 μm vs. 200–250 × 210–340 μm) and longer conidia (24–27 μm long, 3-septate vs. 13–21 μm long, 1-septate) (Thambugala et al. 2017). Since our collection is an asexual morph, and the other three species (B.bambusae, B.ficuum, and B.pustulata) are known as sexual morphs, direct comparisons between them are not feasible. Molecular analyses further support the distinction of B.pseudodimorphae as a novel species. The tef1-α and rpb2 sequences of B.pseudodimorphae differ from those of B.bambusae by 3% (32/924 bp) and 3% (35/1001 bp) nucleotides, respectively. Additionally, the rpb2 sequence of B.pseudodimorphae showed 96% (945/984 bp, one gap) and 97% (853/880 bp, no gap) sequence similarity with B.pustulata and B.dimorpha, respectively. Based on the morphology and molecular evidence, B.pseudodimorphae is identified as a new species following the species delineation guidelines of Jeewon and Hyde (2016).

Bambusicola

autumnalis

Taxon classificationFungiPleosporalesBambusicolaceae



R.R. Liang, S.N. Zhang & Jian K. Liu, Phytotaxa 601(3): 208 (2023)

94562EFE-AD97-5611-A9EB-0A00DBC9F8DF

Figs 6 , 7

Description.

Saprobic on dead bamboo culms. Sexual morph: Ascomata 263–370 μm diam., 185–202 μm high, solitary, scattered to gregarious, initially growing under the host surface, breaking through the surface after maturity, with cracks on the host, subglobose with a flattened base, some arranged in rows, brown to dark brown. Peridium comprising several layers of cells of textura angularis, with dark brown outer layers and hyaline inner layers. Hamathecium of dense, 1–2 μm wide, filamentous, branched, indistinctly septate, smooth-walled, trabeculate pseudoparaphyses, anastomosing at the apex, embedded in a hyaline, gelatinous matrix. Asci 64–95(−102) × (10–)11−14 μm (x̄ = 83 × 12 μm, n = 20), 8-spored, bitunicate, broadly cylindrical to cylindrical-clavate, with a short pedicel, apically rounded with a well-developed ocular chamber. Ascospores (24–)26–29 × 4–6 μm (x̄ = 26 × 5 μm, n = 30), overlapping, biseriate, hyaline, fusiform, with acute ends, 1-septate, slightly constricted at the septa, asymmetric, slightly curved, smooth-walled with 2–4 guttules, surrounded by a thin, inconspicuous mucilaginous sheath. Asexual morph: Coelomycetous, produced on PDA. Conidiomata pycnidial, solitary to gregarious, superficial. Conidiogenous cells 5–17 × 2–4 μm (x̄ = 9 × 3 μm, n = 15), holoblastic, integrated or discrete, subcylindrical to cylindrical, hyaline, smooth, occasionally with an enlarged structure at the top. Conidia with two types, macro- and microconidia. Macroconidia 23–31(–34) × 4–6(–7) μm (x̄ = 28 × 5 μm, n = 30), cylindrical to ellipsoidal, with rounded ends, 3-septate, pale brown to brown, slightly constricted at the septa, smooth. Microconidia 3–6 × 1–2(–3) μm (x̄ = 5 × 2 μm, n = 30), subglobose to ellipsoidal, with rounded to obtuse ends, pale brown, aseptate, smooth-walled.

Bambusicolaautumnalis (HKAS 112598) A, B appearance of ascomata on the host C pseudoparaphyses D vertical section of an ascoma E peridium F germinated ascospore G, H cultures on PDAG from above H from below I–M asci N–R ascospores. Scale bars: 100 µm (D); 25 µm (E, F); 20 µm (I–M); 15 µm (C, N–R).

Culture characteristics.

Colonies on PDA reaching 16 mm diam. after 10 d at 25 °C in dark, white, circular, velvety, with uneven margin. Reverse white with a yellowish center.

Material examined.

China • Guizhou Province, Xingyi City. On dead bamboo stems, 5 September 2019, Yao Feng, XY19-4 (HKAS 112598,GZAAS 21-0500, living cultures CGMCC 3.20354 = GZCC 21-0800; ibid., 6 September 2019, Yao Feng, XY19-1 (GZAAS 21-0389), living culture GZCC 21-0897.

Reproduced Bambusicolaautumnalis (CGMCC 3.20354) A, B colony on PDAC−F conidiogenous cells with macroconidia G−K macroconidia L−N conidiogenous cells with microconidia O microconidia. Scale bars: 10 µm (C−O).

Notes.

Liang et al. (2023) described Bambusicolaautumnalis as a novel species based on its sexual morph and phylogenetic analysis. The phylogenetic results (Fig. 1) confirmed that our new collections are conspecific with B.autumnalis, and this study expands upon their findings by providing a detailed description of the asexual morph, thereby enhancing the taxonomic understanding of this species.

Corylicola

italica

Taxon classificationFungiPleosporalesBambusicolaceae



Wijesinghe, Camporesi, Yong Wang bis & K.D. Hyde, Biodiversity Data Journal 8 (e55957): 8 (2020)

ED4AE79B-9061-5BFA-9B15-8B1973B7873F

Fig. 8

Description.

Saprobic on the branches of Prunusserrulata. Sexual morph: Ascomata 186–292 µm high, 179–267 µm diam., solitary, scattered to gregarious, immersed or erumpent, uniloculate with an ostiole. Peridium 15–30 µm, comprising several layers of cells of textura angularis, with dark brown outer layers and hyaline inner layers. Hamathecium of dense, 1–2 μm wide, filamentous, branched, septate, smooth-walled, cellular pseudoparaphyses, anastomosing at the apex, embedded in a hyaline, gelatinous matrix. Asci 53–66 × 6–8 µm (x̄ = 61 × 7 µm, n = 20), 8-spored, bitunicate, fissitunicate, broadly cylindrical to cylindrical-clavate, with a short pedicel, apically rounded. Ascospores 8–17 × 3–4 µm (x̄ = 13 × 4 µm, n = 30), overlapping, hyaline, fusiform, broader at the top and narrower at the bottom, with a septum in the middle that is deeply constricted, translucent to light brown or brown, rough. Asexual morph: Undetermined.

Corylicolaitalica (GZAAS 21-0243) A, B appearance of ascomata on host C vertical section of an ascoma D peridium E germinated ascospore F pseudoparaphyses G−J asci K−N ascospores. Scale bars: 50 µm (C); 10 µm (D−J); 5 µm (K−N).

Culture characteristics.

Ascospores germinating on PDA within 12 h. Colonies on PDA slow-growing, 9 mm diam. after 10 d at 25 °C in the dark, circular, irregular edges, with dense grayish white mycelium on the surface, in reverse brown to black.

Material examined.

China • Guizhou Province, Xingyi City. On dead stem of Prunusserrulata, 10 July 2018, Yao Feng, nky 141 (GZAAS 21-0243), living culture GZCC 21-0757.

Notes.

The morphology and phylogenetic results confirm that our new collections are identical to Corylicolaitalica. The genus Corylicola was established by Wijesinghe et al. (2020) with C.italica as the type species. This species was originally described from a hanging branch of Corylusavellana in Italy (Wijesinghe et al. 2020). This study represents the first record of C.italica in China.

Discussion

This study presents a comprehensive taxonomic investigation of newly isolated fungal species associated with bamboo, contributing to the growing knowledge of fungal diversity within this unique ecological niche. We describe two new sexual morphs, Bambusicolaellipsospora and B.gelatinosospora, as well as a new asexual morph, B.pseudodimorphae. Additionally, we provide a holomorphic description of B.autumnalis and report Corylicolaitalica for the first time in China. Within the genus Bambusicola, eleven species have been described based on their sexual morphs, including B.aquatica, B.autumnalis, B.bambusae, B.ficuum, B.fusispora, B.hongheensis, B.loculata, B.pustulata, B.subthailandica, B.thailandica, and B.meishanensis. In contrast, five species, B.guttulata, B.irregulispora, B.nanensis, B.sichuanensis, and B.splendida, are classified based solely on their asexual morphs (Dai et al. 2015; Yang et al. 2019; Brahmanage et al. 2020; Monkai et al. 2021; Phukhamsakda et al. 2022; Yu et al. 2022, 2024; Liang et al. 2023). Notably, holomorph are only known for four species: B.didymospora, B.dimorpha, B.massarinia, and B.triseptatispora (Dai et al. 2012, 2017; Thambugala et al. 2017). An intriguing observation in Bambusicola is the ability of certain species, such as B.dimorpha, B.nanensis, B.sichuanensis, and B.pseudodimorphae, to produce both macroconidia and microconidia in culture (Thambugala et al. 2017; Yang et al. 2019; Phukhamsakda et al. 2022; this study). This phenomenon may be linked to environmental factors, particularly nutrient depletion in the growth medium, which could induce the production of conidia in different forms as an adaptive response. Further studies are required to elucidate the genetic and physiological mechanisms regulating this morphological plasticity.

Currently, Bambusicola comprises 20 species (Species Fungorum, accessed 12 February 2025), with 19 species reported from dead bamboo (Dai et al. 2012, 2015, 2017; Dong et al.2020; Thambugala et al. 2017; Monkai et al. 2021; Yang et al. 2019; Yu et al. 2022, 2024, Liang et al. 2023) and only Bambusicolaficuum identified from Ficus (Boonmee et al. 2021). Examining of species distributions within the genus suggests a strong host preference, with most species exhibiting specificity for bamboo (Dai et al. 2012, 2015, 2017; Dong et al.2020; Thambugala et al. 2017; Yang et al. 2019; Monkai et al. 2021; Yu et al. 2022, 2024; Liang et al. 2023). This raises important ecological questions: Do Bambusicola species establish specialized relationships with bamboo through physiological and biochemical mechanisms? Furthermore, does this host specificity make them particularly vulnerable to environmental changes such as climate fluctuations, pest and disease outbreaks, or habitat destruction? Understanding the ecological roles of Bambusicola species is essential for assessing their contributions to bamboo ecosystems. Future research should focus on the mechanisms underlying their interactions with bamboo, including potential mutualistic or pathogenic associations. Such studies will contribute to taxonomic resolution and provide insights into conservation strategies to preserve fungal diversity and maintain ecosystem stability.

Supplementary Material

XML Treatment for Bambusicola ellipsospora

XML Treatment for Bambusicola gelatinosospora

XML Treatment for Bambusicola pseudodimorphae

XML Treatment for Bambusicola autumnalis

XML Treatment for Corylicola italica