Molecular Phylogeny and Morphology Reveal Four Novel Species of Corynespora and Kirschsteiniothelia (Dothideomycetes, Ascomycota) from China: A Checklist for Corynespora Reported Worldwide

Abstract

Plant debris are habitats favoring survival and multiplication of various microbial species. During continuing mycological surveys of saprobic microfungi from plant debris in Yunnan Province, China, several Corynespora-like and Dendryphiopsis-like isolates were collected from dead branches of unidentified perennial dicotyledonous plants. Four barcodes, i.e., ITS, LSU, SSU and tef1-α, were amplified and sequenced. Morphological studies and multigene phylogenetic analyses by maximum likelihood and Bayesian inference revealed three new Corynespora species (C. mengsongensis sp. nov., C. nabanheensis sp. nov. and C. yunnanensis sp. nov.) and a new Kirschsteiniothelia species (K. nabanheensis sp. nov.) within Dothideomycetes, Ascomycota. A list of identified and accepted species of Corynespora with major morphological features, host information and locality was compiled. This work improves the knowledge of species diversity of Corynespora and Kirschsteiniothelia in Yunnan Province, China.

1. Introduction

Hyphomycetes are highly diverse and distributed in terrestrial and freshwater habitats. More than 1500 Hyphomycetes genera and 30,000 species have been recorded worldwide [1,2]. These fungi show distinct morphological features, which often allow for species identification, as DNA sequences have been hitherto unavailable for most genera and species. Given the large amount of hyphomycetes, it is challenging to classify their taxonomic placement based on morphology alone because some of them may belong to the same species or even to different genera. The introduction of molecular phylogenetic analyses led to a better understanding of the heterogenous genera and species and further clarified their taxonomic status. Investigating fungal diversity is an important task in assembling the fungal tree of life (AFToL) [3], which contributes to the knowledge of biological diversity and the exploration and utilization of fungal resources.

Corynespora was established by Güssow [4] with C. mazei as the type species. Wei [5] provided a historical review and considered C. mazei a synonym of the previously described Helminthosporium cassiicola Berk. & M.A. Curtis and transferred the latter species, resulting in the new combination Corynespora cassiicola (Berk. & M.A. Curtis) C.T. Wei. This genus is mainly characterized by distinct, determinate or percurrently extending conidiophores and monotretic, integrated, terminal conidiogenous cells that produce solitary or sometimes catenate, distoseptate conidia [6]. To date, 198 epithets for Corynespora have been listed in Species Fungorum [7], but many species associated with leaf spots were defined at least partially on the basis of host identity. Siboe et al. [8] provided a synopsis of basic characteristics of 50 accepted Corynespora species, but C. kenyensis was not discussed. An additional 93 additional species have since been added to the genus [9,10,11,12,13,14], 87 of which are present in two tables in a format similar to that used by Siboe et al. [8,9,13]. However, C. alternarioides [15], C. camagueyensis [16], C. garciniae [17], C. inornata [18], C. mulanjeensis [19] and C. obclavata [20] were not congeneric with the generic characters in producing euseptate or muriform conidia or synnematous conidiophores with polytretic conidiogenous cells and were excluded from Corynespora [21,22,23,24,25]. Corynespora cespitosa [26], C. endiandrae [11], C. leucadendri [10] and C. olivacea [27] show the main characters of Corynespora but were transferred to Helminthosporium by Voglmayr and Jaklitsch [28] based on morphological and phylogenetic analyses. “Corynespora aeria” [29], “C. ipomoeae” [30] (Art. F.5.1: no identifier number cited), “C. masseeanum” [31] (Art. 41.1: lacking a full and direct basionym reference) and C. ruelliae [32] (Art. 40.1: without assigning a type) were not validly published based on the rules of the International Code of Nomenclature for Algae, Fungi, and Plants [33]. Thus, Corynespora currently contains 129 valid species. Most Corynespora species were introduced primarily based on morphology, and only 10 species with DNA sequences have been used for multigene phylogenetic analyses [12].

Sivanesan [34] introduced the family Corynesporascaceae Sivan. with Corynesporasca carotae Sivan. (= Corynespora calicioidea (Berk. & Broome) M.B. Ellis) [2] as the type species, and first connected the teleomorph (Corynesporasca caryotae) and anamorph (Corynespora) state through cultural studies. Rossman et al. [35] recommended using Corynespora over Corynesporasca, considering its widespread use, priority and number of species. Subsequently, phylogenetic analyses of five gene regions, i.e., SSU, ITS, LSU, rpb2 and tef1-α, revealed that Corynespora smithii forms a separate, distant clade, together with the generic type, C. cassiicola, and is treated in the monotypic Corynesporascaceae in Pleosporales [28].

The genus Kirschsteiniothelia was erected by Hawksworth [36] with K. aethiops as the type species and is mainly characterized by superficial to semi-immersed, subglobose to globose, dark brown to black ascomata; cylindrical clavate, bitunicate, spored asci; and brown to dark brown, ellipsoidal, 1(–2)-septate ascospores with or without a mucilaginous sheath [36,37]. The genus has been linked with two anamorph types, viz., Dendryphiopsis-like and Sporidesmium-like, based on phylogenetic analyses [38]. The Dendryphiopsis-like asexual morph is characteristically macronematous, simple or branched at the apex, forming a stipe and head, brown to dark brown conidiophores with monotretic, integrated, terminal or discrete, determinate or percurrently extending conidiogenous cells that produce solitary, acrogenous, euseptate conidia [38]. The Sporidesmium-like asexual morph has macronematous, unbranched conidiophores with monoblastic, integrated, terminal, determinate or irregular extending conidiogenous cells that produce solitary, acrogenous, euseptate conidia with or without a mucilaginous sheath [38]. Based on morphology and molecular data, previous studies have confirmed that Dendryphiopsis is the anamorph of Kirschsteiniothelia [37,39], and Wijayawardene et al. [40] further demonstrated that Dendryphiopsis atra (generic type) is synonymous with Kirschsteiniothelia atra and suggested using Kirschsteiniothelia rather than Dendryphiopsis, considering the requirement for fewer name changes. Subsequently, seven Sporidesmium-like asexual morphs were reported in Kirschsteiniothelia [38,41,42,43,44].

The early taxonomic placements of Kirschsteiniothelia are uncertain. The genus was originally placed in Pleosporaceae by Hawksworth [36] and Barr [45] and subsequently assigned to Pleomassariaceae by Barr [46] based on asexual morph connection and morphology. Schoch et al. [47] revealed that K. aethiops (generic type) does not cluster with Pleosporaceae in phylogenetic analyses and suggested that Kirschsteiniothelia should be transferred to a new family. Schoch et al. [39] further showed that K. elaterascus and K. maritma cluster within Mytilinidion (Mytilinidiaceae) and Morosphaeria (Morosphaeriaceae), respectively, according to phylogenetic analyses [48], and both species were excluded from Kirschsteiniothelia by Boonmee et al. [37]. In addition, Boonmee et al. [37] introduced a new family, Kirschsteiniotheliaceae, to accommodate taxa grouping with K. aethiops based on morphology and phylogenetic analyses. Hernandez-Restrepo et al. [49] proposed the monotypic order Kirschsteiniotheliales for Kirschsteiniotheliaceae due to its distant relation to other orders in Dothideomycetes.

Yunnan Province is located in southwestern China. It lies at 21°09′–29°15′ N and 97°32′–106°12′ E and includes vast territory with distinct climatic characteristics and abundant natural resources. Its average annual temperatures is 12–22 °C, and the total annual precipitation is approximately 1500 mm. Such favorable conditions support more than 18,000 higher plant species (51.6% of China’s total) in this province, resulting in a very wide range of habitats favoring the growth of various microbial species. However, its mycobiota, especially microfungi, is poorly understood. During our survey of the taxonomy and diversity of saprobic microfungi in Yunnan Province, a Dendryphiopsis-like fungus and three Corynespora-like fungi were collected on dead branches from terrestrial habitats. Based on multilocus phylogenetic analyses and morphological characteristics, we introduced four novel species of Corynespora and Kirschsteiniothelia in Dothideomycetes. This study broadens our understanding of the diversity of Corynespora and Kirschsteiniothelia taxa.

2. Materials and Methods

2.1. Sample Collection, Isolation and Morphology

Samples of dead branches were collected randomly from humid environments and river banks, where there is a deep litter layer comprising rotten softwood, dead branches and decayed leaves of various plants in the forest ecosystems of Yunnan Province. Dead branches are a rich habitat for saprobic hyphomycetes. Samples were placed in Ziploc^TM bags for transport to the laboratory, where they were processed and examined as described by Ma et al. [50]. Colonies on decaying wood surface were examined and visually observed with a stereomicroscope (Motic SMZ-168, Xiamen, China) from low (0.75 times) to high (5 times) magnification. Fresh colonies were picked with sterile needles at a stereomicroscope magnification of 5 times, placed on a slide with a drop of lactic acid–phenol solution (lactic acid, phenol, glycerin, sterile water; 1:1:2:1, respectively), then placed under an Olympus BX 53 light microscope fitted with an Olympus DP 27 digital camera (Olympus Optical Co., Tokyo, Japan) for microscopic morphological characterization. The tip of a sterile toothpick dipped in sterile water was used to capture the conidia of the target colony directly from the specimen; the conidia were then streaked on the surface of potato dextrose agar (PDA; 20% potato + 2% dextrose + 2% agar, w/v) and incubated in an incubator at 25 °C overnight. The single germinated conidia were transferred to fresh PDA plates [51]. Cultures were grown on PDA and incubated in an incubator at 25 °C for 2 weeks; then, morphological characters, including color, shape and size, were recorded. All fungal strains were stored in 10% sterilized glycerin at 4 °C for further studies. The studied specimens and cultures were deposited in the Herbarium of Jiangxi Agricultural University, Plant Pathology, Nanchang, China (HJAUP). The names of the new taxa were registered in Index Fungorum [2].

2.2. DNA Extraction, PCR Amplification and Sequencing

Fungal hyphae were scraped from the surface of colonies growing on PDA plates, transferred to 2 mL safe-lock tubes and ground with liquid nitrogen; then, DNA was extracted using a Solarbio fungal genomic DNA extraction kit (Solarbio, Beijing, China) according to the manufacturer’s instructions. DNA amplification was performed by polymerase chain reaction (PCR) using the respective loci (ITS, SSU, LSU and tef1-α). The following primer sets were used for these genes: ITS: ITS5/ITS4; SSU: NS1/NS4 [52]; LSU: 28S1-F/28S3-R [53]; and tef1-α: EF1-983F/EF1-2218R [54].

The final volume of the PCR reaction was 25 μL, comprising 1 μL of DNA template, 1 μL of each forward and reward primer, 12.5 μL of 2 × Power Taq PCR MasterMix and 9.5 μL of double-distilled water (ddH₂O). The PCR thermal cycling conditions of ITS, SSU and LSU were initialized at 94 °C for 3 min, followed by 35 cycles of denaturation at 94 °C for 30 s, annealing at 55 °C for 50 s, elongation at 72 °C for 1 min and a final extension at 72 °C for 10 min before being maintained at 4 °C; the tef1-α were initialized at 95 °C for 3 min, followed by 35 cycles of denaturation at 95 °C for 30 s, annealing at 60 °C for 30 s, elongation at 72 °C for 1 min and a final extension at 72 °C for 10 min before being maintained at 4 °C. The PCR products were checked by 1% agarose gel electrophoresis staining with ethidium bromide. Purification and DNA sequencing were carried out at Beijing Tsingke Biotechnology Co., Ltd. China. New sequences generated in this study were deposited in the NCBI GenBank (www.ncbi.nlm.nih.gov, accessed on 10 December 2022; Table 1 and Table 2).

Table 1.

List of Corynespora species and GenBank accessions used in the phylogenetic analyses. New sequences are indicated in bold.

Taxon	Strain Number	GenBank Accession Numbers
		SSU	LSU	ITS	tef1- α
Corynespora cassiicola	CBS 100822	GU296144	GU301808	–	GU349052
C. citricola	CBS 169.77	–	–	FJ852594	–
C. doipuiensis	MFLUCC 14–0022	MN648318	MN648326	MN648322	–
C. encephalarti	CBS 145555	–	MK876424	MK876383	–
C. lignicola	MFLUCC 16–1301	–	MN860554	MN860549	–
C. mengsongensis	HJAUP C2000T	OQ060575	OQ060578	OQ060574	–
C. nabanheensis	HJAUP C2048T	OQ060576	OQ060580	OQ060577	OQ067526
C. pseudocassiicola	CPC 31708	–	MH327830	MH327794	MH327877
C. smithii	L120	–	KY984297	KY984297	KY984435
C. smithii	L130	KY984419	KY984298	KY984298	KY984436
C. smithii	CABI 5649b	–	GU323201	FJ852597	GU349018
C. smithii	CBS 139925	–	KY984299	KY984299	–
C. submersa	MFLUCC 16–1101	–	MN860553	MN860548	–
C. torulosa	CBS 136419	–	MH877634	MH866095	–
C. thailandica	CBS 145089	–	MK047505	MK047455	MK047567
C. yunnanensis	HJAUP C2132T	OQ060584	OQ060583	OQ060579	–
Periconia byssoides	H 4600	AB797280	AB807570	LC014581	AB808546
P. digitata	CBS 510.77	AB797271	AB807561	LC014584	AB808537
P. igniaria	CBS 845.96	AB797277	AB807567	LC014586	AB808543
P. macrospinosa	CBS 135663	KP184080	KP184038	KP183999	–
P. pseudodigitata	KT 1395	NG_064850	NG_059396	NR_153490	AB808540
Cyclothyriella rubronotata	TR, CBS 121892	–	KX650541	KX650541	KX650516
C. rubronotata	TR9, CBS 141486	KX650507	KX650544	KX650544	KX650519

“–”, sequence is unavailable. Strain with T (ex-type). Abbreviations: CABI: International Mycological Institute, CABI-Bioscience, Egham, Bakeham Lane, U.K.; CBS: Central Bureau voor Schimmel cultures, Utrecht, The Netherlands; CPC: Collection of Pedro Crous housed at CBS; HJAUP: Herbarium of Jiangxi Agricultural University, Plant Pathology; MFLUCC: Mae Fah Luang University Culture Collection, Chiang Rai, Thailand; SSU: Small Subunit Ribosomal; LSU: Large Subunit Ribosomal; ITS: Internal Transcribed Spacer; tef1-α: Transcriptional Enhancer Factor 1-alpha; others are not registered abbreviations.

Table 2.

List of Kirschsteiniothelia species and GenBank accessions used in the phylogenetic analyses. New sequences are in bold.

Taxon	Strain	Genbank Accession Numbers
		ITS	LSU	SSU
Acrospermum adeanum	M133	EU940180	EU940104	EU940031
A. compressum	M151	EU940161	EU940084	EU940012
A. gramineum	M152	EU940162	EU940085	EU940013
Anisomeridium ubianum	MPN94	–	GU327709	JN887379
Flavobathelium epiphyllum	MPN67	–	GU327717	JN887382
Kirschsteiniothelia aethiops	CBS 109.53	–	AY016361	AY016344
K. aethiops	MFLUCC 16–1104	MH182583	MH182589	MH182615
K. aethiops	S–783	MH182586	MH182595	MH182617
K. aethiops	MFLUCC 15–0424	KU500571	KU500578	KU500585
K. aquatica T	MFLUCC 17–1685	MH182587	MH182594	MH182618
K. arasbaranica	IRAN 2509C	KX621986	KX621987	KX621988
K. arasbaranica T	IRAN 2508C	KX621983	KX621984	KX621985
K. cangshanensis T	MFLUCC 16–1350	MH182584	MH182592	–
K. fluminicola T	MFLUCC 16–1263	MH182582	MH182588	–
K. lignicola T	MFLUCC 10–0036	HQ441567	HQ441568	HQ441569
K. nabanheensis T	HJAUP C2004	OQ023197	OQ023273	OQ023038
K. nabanheensis	HJAUP C2006	OQ023274	OQ023275	OQ023037
K. phoenicis T	MFLUCC 18–0216	MG859978	MG860484	MG859979
K. rostrata T	MFLUCC 15–0619	KY697280	KY697276	KY697278
K. rostrata	MFLUCC 16–1124	–	MH182590	–
K. submersa T	MFLUCC 15–0427	KU500570	KU500577	KU500584
K. submersa	S–481	–	MH182591	MH182616
K. submersa	S–601	MH182585	MH182593	–
K. tectonae T	MFLUCC 12–0050	KU144916	KU764707	–
K. thailandica T	MFLUCC 20–0116	MT985633	MT984443	MT984280
K. thujina	JF 13210	KM982716	KM982718	KM982717
Megalotremis verrucosa	MPN104	–	GU327718	JN887383
Phyllobathelium anomalum	MPN 242	–	GU327722	JN887386
P. firmum	ERP 3175	–	GU327723	–
Pseudorobillarda eucalypti	MFLUCC 12–0422	KF827451	KF827457	KF827463
P. phragmitis	CBS 398.61	MH858101	EU754203	EU754104
Strigula guangxiensis T	HMAS-L0138040	NR_146255	MK206256	–
S. nemathora	MPN 72	–	JN887405	JN887389
Tenuitholiascus porinoides T	HMAS-L0139638	–	MK206259	MK352441
T. porinoides	HMAS-L0139639	–	MK206258	MK352442
T. porinoides	HMAS-L0139640	–	MK206260	MK352443

“–”, sequence is unavailable; strain with T, ex type. Abbreviations: CBS: Central Bureau voor Schimmel cultures, Utrecht, the Netherlands; HJAUP: Herbarium of Jiangxi Agricultural University, Plant Pathology; HMAS: Fungarium-Lichenum of the Institute of Microbiology, Chinese Academy of Sciences; IRAN: Iranian Fungal Culture Collection, Iranian Research Institute of Plant Protection, Tehran, Iran; MFLUCC: Mae Fah Luang University Culture Collection, Chiang Rai, Thailand; ITS: internal transcribed spacer; LSU: large subunit ribosomal; SSU: small subunit ribosomal; others are not registered abbreviations.

2.3. Phylogenetic Analyses

The newly generated sequences, together with other sequences obtained from GenBank (four loci: ITS, LSU, SSU and tef1-α (Table 1); three loci: ITS, LSU and SSU (Table 2)), were separately aligned using the MAFFTv.7 [55] online server (http://maffTh.cbrc.jp/alignment/server/, accessed on 23 December 2022) and manually optimized when needed. Phylogenetic analyses were first conducted individually for each locus, then for a combined dataset of these loci. The four ITS, LSU, SSU and tef1-α alignment datasets and the three ITS, LSU and SSU alignment datasets were concatenated with Phylosuite software v1.2.2 [56], and absent sequence data in the alignments were treated with a question mark as missing data. Phylosuite software v1.2.2 [56] was used to construct separate phylogenetic trees based on ITS, LSU, SSU and tef1-α sequence data, as well as ITS, LSU and SSU sequence data. The concatenated and aligned datasets were analyzed separately using maximum likelihood (ML) and Bayesian inference (BI). The maximum-likelihood phylogenies were inferred using IQ-TREE [57] under an edge-linked partition model for 10000 ultrafast bootstraps [58]. For Corynespora, the final tree was selected among suboptimal trees from each run by comparing the likelihood scores using SYM+G4 for ITS, TNe+G4 for LSU+tef1-α and K2P+I for the SSU substitution model. Bayesian inference phylogenies were inferred using MrBayes 3.2.6 [59] under a partition model (2 parallel runs, 2000000 generations), in which the initial 25% of sampled data were discarded as burn-in. The best-fit model was SYM+G4 for ITS, GTR+F+G4 for LSU+tef1-α and K2P+I for SSU. For Kirschsteiniothelia, the final tree was selected among suboptimal trees from each run by comparing the likelihood scores using TIM2e+R3 for ITS+SSU and TN+F+G4 for the LSU substitution model. Bayesian inference phylogenies were inferred using MrBayes 3.2.6 [59] under a partition model (2 parallel runs, 2000000 generations), in which the initial 25% of sampled data were discarded as burn-in. The best-fit model was SYM+G4 for ITS+LSU+SSU. ModelFinder [60] was used to select the best-fit partition model (edge-linked) using the BIC criterion. The trees were viewed in FigTree v. 1.4.4 (http://tree.bio.ed.ac.uk/software/figtree, accessed on 10 December 2022) and further edited in Adobe Illustrator 2021.

3. Results

3.1. Molecular Phylogeny

The phylogenetic tree (Figure 1) inferred from maximum-likelihood and Bayesian inference analyses based on combined ITS, LSU, SSU and tef1-α sequence data consisted of three families (Corynesporascaceae, Periconiaceae and Cyclothyriellaceae). The concatenated sequence matrix comprised 23 sequences with 3147 total characters (the combined dataset, ITS: 1–498, LSU: 499–1348, SSU: 1349–2374, tef1-α: 2375–3147), 537 distinct patterns, 375 parsimony-informative sites, 147 singleton sites and 2625 constant sites; Cyclothyriella rubronotata (TR) and C. rubronotata (TR9) were regarded as an outgroup. Maximum-likelihood and Bayesian inference analyses of the combined dataset resulted in phylogenetic reconstructions with largely similar topologies; the best-scoring ML tree is shown in Figure 1. Bootstrap support values for maximum likelihood higher than 75% and Bayesian posterior probabilities greater than 0.90 are shown above the nodes. The best-scoring ML consensus tree (lnL = –8859.832) with ultrafast bootstrap values from ML analyses and posterior probabilities from MrBayes analysis at the nodes is shown in Figure 1. The strains of Corynespora mengsongensis form a distinct clade sister to C. nabanheensis with good statistical support (ML/BI = 85/0.95); C. yunnanensis forms a high-support clade (ML/BI = 99/1.00) with the lineage consisting of C. mengsongensis and C. nabanheensis, and they form a sister clade to C. submersa (ML/BI =85/0.75).

Figure 1.

Phylogram of Pleosporales based on combined ITS, SSU, LSU and tef1-α sequences. ML and BI bootstrap support values above 75% and 0.90 are shown at the first and second position, respectively. The tree is rooted to Cyclothyriella rubronotata (TR) and C. rubronotata (TR9). Strains from the current study are indicated in red.

The phylogenetic tree (Figure 2) inferred from maximum-likelihood and Bayesian inference analyses based on combined ITS, LSU and SSU sequence data consisted of four orders (Acrospermales, Kirschsteiniotheliales, Monoblastiales and Strigulales). The concatenated sequence matrix comprised 36 sequences with 1260 total characters (combined dataset, ITS: 1–162, LSU: 163–471, SSU: 472–1260), 413 distinct patterns, 253 parsimony-informative sites, 183 singleton sites and 824 constant sites; Pseudorobillarda eucalypti (MFLUCC 12–0422) and P. phragmitis (CBS 398.61) were regarded as an outgroup. Maximum-likelihood and Bayesian inference analyses of the combined dataset resulted in phylogenetic reconstructions with largely similar topologies; the best-scoring ML tree is shown in Figure 2. Bootstrap support values for maximum likelihood higher than 75% and Bayesian posterior probabilities greater than 0.90 are shown above the nodes. The best-scoring ML consensus tree (lnL = –6307.741) with ultrafast bootstrap values from ML analyses and posterior probabilities from MrBayes analysis at the nodes is shown in Figure 2. The strains of K. nabanheensis form a separate clade closely related to K. thailandica, K. thujina, K. tectonae and K. rostrata, with strong statistical support (ML/BI = 95/0.98).

Figure 2.

Phylogram of Kirschsteiniotheliales, Acrosperales, Strigulales and Monoblastiales based on combined ITS, SSU and LSU sequences. The ML and BI bootstrap support values above 75% and 0.90 are shown at the first and second position, respectively. The tree is rooted to Pseudorobillarda eucalypti (MFLUCC 12–0422) and P. phragmitis (CBS 398.61). Strains from the current study are indicated in red.

3.2. Taxonomy

Corynespora mengsongensis Jing W. Liu & Jian Ma, sp. nov., Figure 3.

Figure 3.

Corynespora mengsongensis (HJAUP M2000, holotype). (a) Surface of colony after 2 weeks on PDA; (b) reverse of colony after 2 weeks on PDA; (c–f) conidiophores, conidiogenous cells and conidia; (g) conidia; (h) conidiogenous cells with developing conidia.

Indexfungorum number: IF900076

Etymology: The name refers to Mengsong, the township where the fungus was collected.

Holotype: HJAUP M2000.

Description: Saprobic on decaying wood in terrestrial habitats. Teleomorph: undetermined. Anamorph (Figure 3): Hyphomycetes. Colonies on natural substratum are effuse, brown to dark brown and hairy. Mycelium is superficial and immersed, composed of branched, septate, pale brown to brown, smooth-walled hyphae. Conidiophores are macronematous, mononematous, unbranched, erect, straight or flexuous, cylindrical, smooth, brown to dark brown and septate, with up to 2 successive cylindrical extensions (267–)746–938 × 12.5–17 μm ($\overline{\mathrm{X}}$ = 829 × 14.5 μm, n = 15). Conidiogenous cells are integrated, terminal, monotretic, cylindrical, pale brown to brown and smooth, with dimensions of 25–29 × 8.5–10.5 µm ($\overline{\mathrm{X}}$ = 27 × 9.4 μm, n = 15). Conidia are acrogenous, solitary, obclavate, rostrate, rounded at the apex, straight or slightly curved, 13–18-distoseptate, brown to golden brown and smooth, with dimensions of 96–146 × 16.5–20.5 μm ($\overline{\mathrm{X}}$ = 118.5 × 18.5 μm, n = 20), tapering to 3–4 μm near the apex and truncate at the base, with a protuberant dark-brown hilum that is 6–8 μm wide at the base.

Culture characteristics: Colony on PDA reaching 80–88 mm diam. after 2 weeks in an incubator under dark conditions at 25 °C; irregular circular, velvety surface with dense, gray–white mycelia along the entire margin; reverse brown to dark brown.

Material examined: China, Yunnan Province, Xishuangbanna Dai Autonomous Prefecture, Menghai County, Mengsong Township, on dead branches of an unidentified broadleaf tree, 12 July 2021, J.W. Liu (HJAUP M2000, holotype; ex-type culture permanently preserved in a metabolically inactive state, HJAUP C2000).

Notes: Phylogenetic analyses showed that C. mengsongensis cluster with C. nabanheensis (Figure 1). BLASTn analysis of C. mengsongensis (HJAUP C2000^T) and C. nabanheensis (HJAUP C2048^T) shows 90% identity (540/598, 22 gaps) using ITS, 97% identity (559/578, 3 gaps) using LSU and 99% identity (1021/1026, no gaps) using SSU. Corynespora mengsongensis are morphologically similar to C. merrilliopanacis [61], but the latter differ in terms of their longer conidiophores (260–1200 μm), with up to 5 successive cylindrical extensions and longer conidia (130–260 μm) with 12–25 distosepta. Furthermore, C. mengsongensis differ from C. nabanheensis, which have smaller conidiophores (282–528 × 6–8 μm) with 3–4 successive cylindrical extensions and smaller conidia (56–84 × 12–14 μm) with 9–13 distosepta.

Corynespora nabanheensis Jing W. Liu & Jian Ma, sp. nov., Figure 4.

Figure 4.

Corynespora nabanheensis (HJAUP M2048, holotype). (a) Surface of colony after 2 weeks on PDA; (b) reverse of colony after 2 weeks on PDA; (c) conidia; (d,e) conidiophores and conidiogenous cells; (f–h) conidiophores, conidiogenous cells and conidia.

Index Fungorum number: IF900077

Etymology: The name refers to Nabanhe Nature Reserve, the locality where the fungus was collected.

Holotype: HJAUP M2048.

Description: Saprobic on decaying wood in terrestrial habitats. Teleomorph: undetermined. Anamorph (Figure 4): hHyphomycetes. Colonies on natural substratum are effuse, brown to dark brown and hairy. Mycelia are superficial and immersed, composed of branched, septate, pale brown to brown, smooth-walled hyphae. Conidiophores are macronematous, mononematous, unbranched, erect, straight or flexuous, cylindrical, smooth and brown to dark brown, with 10–17-septate with 3–4 successive cylindrical extensions and dimensions of 282–528 × 6–8 μm ($\overline{\mathrm{X}}$ = 388 × 7 μm, n = 15). Conidiogenous cells are integrated, terminal, monotretic, cylindrical, pale brown to brown and smooth, with dimensions of 20–32 × 5–8 µm ($\overline{\mathrm{X}}$= 25.5 × 6.5 μm, n = 15). Conidia are acrogenous, solitary, obclavate, rostrate and straight or slightly curved with 9–13-distoseptate, brown to golden brown, smooth and usually expanded to a rounded shape at the apex, with dimensions of 56–84 × 12–14 μm ($\overline{\mathrm{X}}$ = 66.5 × 13 μm, n = 20) and 4–6 μm near the apex and truncated at the base, with a protuberant dark brown hilum that is 4–5 μm wide at the base.

Culture characteristics: Colonies on PDA reach 85–90 mm diam. after 2 weeks in an incubator under dark conditions at 25 °C, with an irregular, circular, velvety surface and dense, gray mycelia along the entire margin; reverse brown to black.

Material examined: China, Yunnan Province, Xishuangbanna Dai Autonomous Prefecture, the Nabanhe National Nature Reserve, on dead branches of an unidentified broadleaf tree, 12 July 2021, J.W. Liu (HJAUP M2048, holotype; ex-type culture permanently preserved in a metabolically inactive state HJAUP C2048).

Notes: Phylogenetic analyses showed that C. nabanheensis cluster with C. mengsongensis (Figure 1). BLASTn analysis of C. nabanheensis (HJAUP C2048^T) and C. mengsongensis (HJAUP C2000^T) shows 90% identity (540/598, 22 gaps) using ITS, 97% identity (559/578, 3 gaps) using LSU and 99% identity (1021/1026, no gaps) using SSU. Corynespora nabanheensis are morphologically similar to C. doipuiensis [12], but the latter differ in terms of their shorter and wider conidiophores (212–426 × 10–15 μm), with fewer successive cylindrical extensions and larger, obconical, guttulate, subhyaline to moderately brown conidia (136–165 × 5–25.5 μm). Furthermore, C. nabanheensis differ from C. mengsongensis, which have larger conidiophores (746–938 × 12.5–17 μm), with up to 2 successive cylindrical extensions and larger conidia (96–146 × 16.5–20.5 μm) with 13–18 distosepta.

Corynespora yunnanensis Jing W. Liu & Jian Ma, sp. nov., Figure 5.

Figure 5.

Corynespora yunnanensis (HJAUP M2132, holotype). (a) Surface of colony after 2 weeks on PDA; (b) reverse of colony after 2 weeks on PDA; (c) conidia; (d) conidiogenous cells and conidia; (e–g) conidiophores, conidiogenous cells and conidia.

Index Fungorum number: IF900078.

Etymology: The name refers to Yunnan, the province where the fungus was collected.

Holotype: HJAUP M2132.

Description: Saprobic on decaying wood in terrestrial habitats. Teleomorph: undetermined. Anamorph (Figure 5): Hyphomycete. Colonies on natural substratum are effuse, brown to dark brown and hairy. Mycelia are superficial and immersed, composed of branched, septate, pale brown to brown, smooth-walled hyphae. Conidiophores are macronematous, mononematous, unbranched, erect, straight or flexuous, cylindrical, smooth, septate and brown to dark brown, with 1–4 successive cylindrical extensions and dimensions of 380–844 × 8–16 μm ($\overline{\mathrm{X}}$ = 547 × 12.5 μm, n = 15). Conidiogenous cells are integrated, terminal, monotretic, cylindrical, pale brown to brown and smooth, with dimensions of 44–120(–332) × 6–8 µm ($\overline{\mathrm{X}}$ = 55.5 × 6.5 μm, n = 15). Conidia are acrogenous, solitary, obclavate, rostrate, rounded at the apex, straight or slightly curved, 3–16-distoseptate, brown to golden brown and smooth, with dimensions of 80–128 × 16–19 μm ($\overline{\mathrm{X}}$ = 117 × 18 μm, n = 25), tapering to 4–8 μm near the apex, and truncated at the base with a protuberant dark brown hilum that is 6–8 μm wide at the base.

Culture characteristics: Colonies on PDA reach 78–85 mm diam. after 2 weeks in an incubator under dark conditions at 25 °C, with an irregular, circular, velvety surface with dense, gray mycelia along the entire margin; reverse brown to black.

Material examined: China, Yunnan Province, Xishuangbanna Dai Autonomous Prefecture, Jinghong City, Gasa Township, on dead branches of an unidentified broadleaf tree, 12 July 2021, J.W. Liu (HJAUP M2132, holotype; ex-type culture permanently preserved in a metabolically inactive state HJAUP C2132).

Notes: Phylogenetic analyses showed that C. yunnanensis cluster with C. mengsongensis and C. nabanheensis, and they form a sister clade to C. submersa (Figure 1). BLASTn analysis of C. yunnanensis (HJAUP C2132^T) and C. mengsongensis (HJAUP C2000^T) shows 99% identity (567/569, 2 gaps) using ITS, 98% identity (577/587, 7 gaps) using LSU and 99% identity (1028/1029, no gaps) using SSU. BLASTn analysis of C. yunnanensis (HJAUP C2132^T) and C. nabanheensis (HJAUP C2048^T) shows 91% identity (518/569, 20 gaps) using ITS, 97% identity (543/558, 1 gap) using LSU and 99% identity (1024/1028, no gaps) using SSU. BLASTn analysis of C. yunnanensis (HJAUP C2132^T) and C. submersa (MFLUCC 16-1101) shows 100% identity (487/487, no gaps) using ITS and 99% identity (544/547, 1 gap) using LSU. Corynespora yunnanensis are morphologically similar to C. submersa [12], but the latter differ by in terms of their shorter and narrower conidiophores (150–370 × 10–12 μm) and larger, catenate conidia (100–150 × 16–24 μm), with 9–13 distosepta. Furthermore, C. yunnanensis differ from C. mengsongensis, which have larger conidiophores (746–938 × 12.5–17 μm), with up to 2 successive cylindrical extensions, and larger conidia (96–146 × 16.5–20.5 μm) with 13–18 distosepta, as well as from C. nabanheensis, which have smaller conidiophores (282–528 × 6–8 μm) and smaller conidia (56–84 × 12–14 μm) with 9–13 distosepta.

Kirschsteiniothelia nabanheensis Jing W. Liu & Jian Ma, sp. nov., Figure 6.

Figure 6.

Kirschsteiniothelia nabanheensis (HJAUP M2004, holotype). (a) Surface of colony after 2 weeks on PDA; (b) reverse of colony after 2 weeks on PDA; (c) conidia; (d) conidiogenous cells and conidia; (e–g) conidiophores, conidiogenous cells and conidia; (h) conidiophores and conidiogenous cells.

Index Fungorum number: IF900082.

Etymology: The name refers to Nabanhe Nature Reserve, the locality where the fungus was collected.

Holotype: HJAUP M2004.

Description: Saprobic on decaying wood in terrestrial habitats. Teleomorph: undetermined. Anamorph (Figure 6): Hyphomycetes. Colonies on natural substratum are effuse, brown to black and hairy. Mycelia are superficial and immersed, composed of branched, septate, pale brown to brown, smooth-walled hyphae. Conidiophores are macronematous, mononematous, erect, irregular or subscorpioid branched near the apex, solitary, smooth, cylindrical, straight to flexuous, septate and black–brown to brown, with dimensions of (200–)320–588 × 8–12 μm ($\overline{\mathrm{X}}$ = 405 × 9.5 μm, n = 15). Conidiogenous cells are monotretic, integrated, terminal or intercalary, cylindrical or doliiform, determinate, smooth and brown to dark brown, with dimensions of 20–24 × 4–6 µm ($\overline{\mathrm{X}}$ = 22 × 5 μm, n = 15). Conidia are acrogenous, solitary, obclavate or fusiform, sometimes rostrate, straight or slightly curved, 3–7-euseptate, dark brown to brown and smooth, with dimensions of 32–112 × 8–12 μm ($\overline{\mathrm{X}}$ = 55.5 × 10 μm, n = 25), tapering to 3–4 μm near the apex, with a width of 4–5 μm at the base.

Culture characteristics: Colonies on PDA reach 85–90 mm diam. after 2 weeks in an incubator under dark conditions at 25 °C, with an irregular, circular, velvety surface with dense, gray–brown mycelia along the entire margin; reverse brown to dark brown.

Material examined: China, Yunnan Province, Xishuangbanna Dai Autonomous Prefecture, the Nabanhe National Nature Reserve, on dead branches of an unidentified broadleaf tree, 12 July 2021, J.W. Liu (HJAUP M2004, holotype; ex-type culture permanently preserved in a metabolically inactive state HJAUP C2004 = HJAUP C2006).

Notes: Phylogenetic analyses showed that K. nabanheensis cluster with K. thailandica, K. thujina, K. tectonae and K. rostrata, and they form a sister clade to K. submersa (Figure 2). BLASTn analysis of K. nabanheensis (HJAUP C2004^T) and K. rostrata (MFLUCC 15–0619^T) shows 85% identity (473/558, 27 gaps) using ITS, 95% identity (519/548, 4 gaps) using LSU and 99% identity (875/886, no gaps) using SSU. BLASTn analysis of K. nabanheensis (HJAUP C2004^T) and K. tectonae (MFLUCC 12–0050^T) shows 84% identity (458/548, 35 gaps) using ITS and 95% identity (523/548, 4 gaps) using LSU. Kirschsteiniothelia nabanheensis are morphologically similar to K. shimlaensis, but the latter differ in terms of their shorter and wider conidiophores (110–268 × 12–19 μm), and shorter and wider, obovoid, oblong, clavate or cylindrical conidia (41–81 × 13–17.5 μm) with 2–5(–6) eusepta [62]. Furthermore, K. nabanheensis differ from K. submersa which have smaller conidiophores (220–280 × 6–7 μm) and holoblastic conidiogenous cells producing smaller conidia (37.5–51.5 × 8.5–9.5 μm) with 4–6 eusepta [42].

4. Discussion

In this study, we collected saprophytic hyphomycetes on dead branches from terrestrial habitats in Yunnan Province, China. Based on the morphomolecular approach, four novel taxa are introduced: Corynespora mengsongensis sp. nov., C. nabanheensis sp. nov., C. yunnanensis sp. nov. and Kirschsteiniothelia nabanheensis sp. nov.

Corynespora show high morphological similarity to Corynesporina, Corynesporopsis, Hemicorynespora and Solicorynespora in terms of their terminal, monotretic, conidiogenous cells and differ only on the basis of single conidial characteristics (e.g., single or catenate, euseptate or distoseptate, basipetal chain or acropetal chain) [63]. The weak differentiation of these similar genera should only be maintained until sufficient molecular analysis allows for a more phylogenetic classification of genera. In addition, it is challenging to separate Corynespora from Helminthosporium based on morphology alone, as four Corynespora species, C. caespitosa, C. endiandrae, C. leucadendri and C. olivacea, were transferred to Helminthosporium based on molecular phylogenetic analyses, which led to the genus Helminthosporium also meeting the criteria of Corynespora [28].

The genus Corynespora produces conspicuous morphological features, and its generic type, C. cassiicola, is a ubiquitous species, mainly in tropical and subtropical areas, and has been recorded from a wide range of plants [64]. Most Corynespora species are known as saprobes and plant pathogens from woody and herbaceous hosts [8,9,13], but occasionally, C. cassiicola is also found in nematodes, sponges and human skin [64]. To date, 132 species of Corynespora (Table 3) have been be accepted worldwide, whereas four invalid names enclosed in quotation marks are also listed in Table 3. Many species have been identified only based on morphological studies, and only 13 species, including our three new species, have been subjected to molecular phylogenetic analyses. Morphological comparison is important for species identification, but the lack of a large amount of molecular data made it difficult to evaluate previously described Corynespora species by molecular methods. Thus, we recommend supplementary sequence data for previously described Corynespora species by re-examining their type materials or collecting fresh new specimens and using molecular phylogenetic analyses to evaluate their taxonomic placement as necessary.

Hawksworth [36] established the genus Kirschsteiniothelia and regarded K. aethiops as the type species. Boonmee et al. [37] treated the genus in a new family, Kirschsteiniotheliaceae, based on evidence from morphological and phylogenetic analyses. Hernandez-Restrepo et al. [49] raised Kirschsteiniotheliaceae to the new order Kirschsteiniotheliales in Dothideomycetes, although this order does not form a well-supported clade within Dothideomycetidae as a sister clade to Asterinales; the two orders diverged approximately 221 MYA according to divergence time estimates [65].

Sun et al. [38] accepted five former Dendryphiopsis species, D. arbuscula, D. binsarensis, D. biseptata, D. fascicularis and D. goaensis, in Kirschsteiniothelia following the latest treatment of Dendryphiopsis by Wijayawardene et al. [40]. However, these five species were invalidly introduced as new combinations in Kirschsteiniothelia on the basis of Art. F.5.1 (no identifier number cited) and Art. 41.1 (lacking a full and direct basionym reference) of the International Code of Nomenclature for Algae, Fungi, and Plants [33]. In addition, Sun et al. [38] provided a checklist for 35 Kirschsteiniothelia species including the distribution, habitat, host and morphology type of each species, but K. ebriosa [66] and K. vinigena [66] are not included. Subsequently, Verma et al. [62] described a new species, K. shimlaensis, from decaying stump in India.

Table 3.

Synopsis of conidial characteristics, host information and locality compared across Corynespora species.

Species	Conida					Host/Locality	References
	Production	Morphology	Color	Size (µm)	Septation
Corynespora acaciae	Solitary	Obclavate	Dark brown	16–30 × 6–8	1–5	On phyllodes of Acacia pycnantha, Australia	[67]
C. acalyphae	Solitary	Obclavate, rostrate	Pale brown to brown	85–120 × 9–11	8–16	On dead branches of Acalypha hamiltoniana, Indonesia	[68]
C. achradis	Solitary or catenate	Obclavate, rostrate	Pale olivaceous brown	60–95 × 6–7	5–10	On leaves of Achras sapota, Brunei	[69]
“C. aeria”	Solitary	Obclavate	Subhyaline to olivaceous	Up to 350 × 2–5	1–5	Isolated from air, India	[29]
C. albiziicola	Solitary	Obclavate, ellipsoid or clavate	Pale olivaceous yellow	20–70.1 × 10–18.5	1–6	On leaves of Albizia lebbek, India	[70]
C. alstoniae	Solitary or catenate	Cylindrical to obclavate	Subhyaline to light olivaceous	48–154 × 8–21.5	2–15	On leaves of Alstonia scholaris, Nepal	[71]
C. annonacea	Solitary or catenate	Obclavate to obclavate–cylindrical	Subhyaline to olivaceous brown	25–135 × 10–18	1–10	On living leaves of Annona squamosa, India	[72]
C. aquatica	Solitary	Obclavate to cylindrical	Pale brown	34–46 × 3–4.5	(1–)2(–3)	On decaying leaves submerged in stream, Mexico	[24]
C. arctespora	Solitary or catenate	Cylindrical to obclavate	Brown to pale brown	13–63 × 4–7	2–20	On twigs of Vaccinium, USA	[73]
C. asclepiadacearum	Mostly solitary	Obclavato-cylindric to cylindrical	Pale olivaceous brown	44–192 × 10–25	Up to 26	On leaves of Cryptolepis buchananii, India	[74]
C. azadirachtiana	Solitary or catenate	Obclavate	Pale yellow	32–303.5 × 7–21.5	1–20	On leaves of Azadirachta indica, India	[75]
C. barleriicola	Solitary	Obclavate to cylindrical	Olivaceous yellow	41–246 × 10–18.5	3–14	On leaves of Barleria cristata, India	[75]
C. bdellomorpha	Solitary	Obclavate	Mid to dark-reddish brown	90–138 × 12–17	12–19	On dead stems of Chusquea valdiviensis, Chile	[26]
C. beilschmiediae	Solitary	Obclavate	Pale brown to brown	52–144.5 × 8.5–11	7–19	On dead branches of Beilschmiedia intermedia, China	[76]
C. bombacearum	Solitary or catenate	Obclavato-cylindrical to cylindrical	Pale to mid-olivaceous	26–206 × 8.5–17	Up to 15	On leaves of Bombax malabaricum, India	[77]
C. bombacina	Solitary or catenate	Obclavate to cylindrical	Light olivaceous	45–180 × 10–16	5–15	On living leaves of Bombax ceiba, India	[78]
C. calicioidea	Solitary	Obclavate	Subhyaline to pale golden brown	50–170 × 10–15	6–21	On wood, Sri Lanka	[79]
C. carrisae	Solitary	Obclavate to cylindrical	Olivaceous to very light brown	75–242 × 6–14	4–17	On leaves of Carissa spinarum, India	[80]
C. caryotae	Solitary	Obclavate to elongate	Pinkish brown	45–120 × 6–10	Up to 18	On dead rachis of Caryota mitis, Singapore	[81]
C. cassiae	Solitary	Obclavate	Pale brown to olivaceous brown	107.5–214 × 11–14	10–21	On dead branches of Cassia surattensis, China	[76]
C. cassiicola	Solitary or catenate	Obclavate to cylindrical	Subhyaline to pale olivaceous brown	40–220 × 9–22	4–20	On leaves of Cassia, Cuba	[5]
C. catenulata	Solitary or catenate	Obclavate to obclavato-cylindrical	Dark olivaceous yellow to pale olivaceous brown	27.5–225.5 × 11–19	1–24	On leaves of Clerodendrum indicum, India	[75]
C. catharanthicola	Solitary or catenate	Cylindrical	Brown	140–310 × 5.5–11	4–25	On leaves of Catharanthus roseus, China	[82]
C. celastri	Solitary	Obclavate to obclavato-cylindrical	Olivaceous to very light brown	55–120 × 8–15	7–17	On living leaves of Celastrus paniculatus, India	[83]
C. chinensis	Catenate	Obclavate	Pale brown	31–61 × 5–7.5	1–5	On dead branches of Angiospermae, China	[14]
C. citricola	Solitary or catenate	Cylindrical to obclavate	Subhyaline	48–150 × 4.5–8	4–18	On leaves of Citrus aurantiifolia, Australia	[79]
C. clerodendrigena	Solitary or catenate	Obclavate to cylindrical	Light olivaceous	60–220 × 16–22	3–13	On leaves of Clerodendrum viscosum, India	[84]
C. colebrookiana	Solitary or catenate	Obclavate, rarely cylindrical	Pale yellow	45–330 × 6–22	4–16	On leaves of Colebrookea oppositifolia, India	[75]
C. combreli	Solitary	Obclavate, rostrate	Pale olivaceous brown to olivaceous brown	40–122 × 8–11	4–10	On dead branches of Combretum zeyheri, Zambia	[85]
C. cubensis	Solitary or catenate	Cylindrical to obclavate	Pale brown to dark rusty brown	40–80 × 8–12	6–15	On dead petiole of Coccothrinax, Cuba	[86]
C. cucurbiticola	Solitary or catenate	Obclavato-cylindrical	Subhyaline to pale olivaceous	38.5–230 × 6.5–20	6–23	On leaves of Coccinia grandis, Nepal	[87]
C. curvispora	Solitary or catenate	Narrow obclavate	Straw-colored to mid-brown	40–250 × 10–12	5–10	On fallen herbaceous stems, USA	[88]
C. doipuiensis	Solitary	Obclavate to cylindrical	Subhyaline to moderately brown	136–165 × 5–25.5	–	On dead herbaceous branches, Thailand	[12]
C. donacis	Solitary	Obclavate	Olivaceous brown	45–70 × 8–12	10–14	On dead branches of Donax, China	[89]
C. elaeidicola	Solitary or catenate	Cylindrical to obclavate	Subhyaline or pale olivaceous brown	43–65 × 4–7	3–7	On dead leaves of Elaeis guineensis, Malaysia	[27]
C. encephalarti	Solitary	Obclavate	Medium olivaceous brown	100–150 × 11–15	1–12	On leaves of Encephalartos, South Africa	[90]
C. eranthemi	Solitary	Obclavate	Brown to pale olivaceous brown	65–176 × 11–14	5–25	On leaves of Eranthemum wattii, Singapore	[32]
C. erythropsidis	Solitary	Ellipsoid, doliiform to broad clavate	Pale brown to olivaceous brown	25–31 × 9–12	4	On dead branches of Erythropsis colorata, China	[91]
C. euphorbiacearum	Solitary or catenate	Obclavate	Subhyaline to light olivaceous brown	59–235 × 11–22.5	5–18	On leaves of Manihot esculenta, India	[71]
C. euryae	Solitary	Obclavate	Pale brown to brown	36–67 × 6–9	5–9	On dead branches of Eurya inaequalis, China	[92]
C. fici-altissimae	Solitary	Obclavate, rostrate	Dark brown	55–85 × 9–12	11–18	On dead branches of Ficus altissima, China	[89]
C. fici-benjaminae	Solitary	Obclavate	Pale olivaceous brown	51.5–71 × 8–11	5–10	On dead branches of Ficus benjamina, China	[76]
C. ficigena	Solitary	Obclavate to cylindrical	Light olivaceous brown	90–165 × 9–20	7–13	On leaves of Ficus religiosa, India	[93]
C. flagellata	Solitary	Obclavate, rostrate, smooth or verrucose	Dark brown	50–100 × 9–11	5–10	On wood of Citrus, Ghana	[94]
C. fujianensis	Solitary	Obclavate	Brown	31–90 × 6.5–10	4–10	On dead branches of Myrioneuron faberi, China	[95]
C. gigaspora	Solitary	Obclavate, rostrate	Pale to dark golden brown	100–270 × 19–28	9–52	On dead wood, Sri Lanka	[79]
C. gorakhpurensis	Solitary	Obclavate to ellipsoid	Pale olivaceous yellow	21–157 × 13–20	3–13	On leaves of Erythrina indica, India	[70]
C. gracilis	Solitary	Cylindric to obclavate	Olivaceous	92–138 × 5–7	10–22	On dead branches of Piper betle, Indonesia	[68]
C. gymnocladi	Solitary	Obclavate	Brown to dark brown	15–40 × 7–10.5	2–6	On dead branches of Gymnocladus chinensis, China	[92]
C. hamata	Solitary	Obclavate, hamatate at apex	Pale olivaceous brown	158–198 × 9–11	14–19	On dead wood, Indonesia	[68]
C. hansfordii	Solitary	Obclavate, rostrate	Straw-colored to brown	70–100 × 9–13	7–10	On dead wood, Uganda	[27]
C. hemigraphidis	Solitary	Obclavate	Pale olivaceous brown	72–218 × 12–15	5–25	On leaves of Hemigraphis alternat, Singapore	[32]
C. heterospora	Solitary	Cylindrical to obclavate	Pale olivaceous brown to olivaceous brown	75–170 × 6–20	6–12	On leaves of Manihot utilissima, Malaysia	[96]
C. holopoteleae	Solitary or catenate	Obclavato-cylindrical to cylindrical	Mid olivaceous	23–234 × 3.6–19.5	0–17	On leaves of Holoptelea integrifolia, India	[77]
C. holopteleicola	Solitary	Obclavate to obclavato-cylindrical	Olivaceous brown	33–148 × 5–20	0–11	On living leaves of Holoptelea integrifolia, India	[72]
C. homaliicola	Solitary	Obclavate, cylindrical	Subhyaline to straw-colored	110–220 × 11–22	13–28	On dead branches of Homalium aylmeri, Sierra Leone	[79]
“C. ipomoeae”	Solitary or catenate	Obclavate to cylindrical	Subhyaline to pale olivaceous	40–380 × 5–15	2–35	On leaves of Ipomoea obscura, India	[30]
C. jasminicola	Solitary	Obclavate	Pale olivaceous	39.5–176 × 10–21	2–18	On leaves of Jasminum arborescens, Nepal	[87]
C. kamatii	Solitary	Obclavate	Straw-colored	60–70 × 10–13	7–12	On dead twigs of Vitis, India	[69]
C. kenyensis	Solitary	Obclavate to obpyriform, rostrate	Subhyaline to pale brown	60–125 × 16–25	8–15	On dead stems of Sericostachys scandens, Kenya	[8]
C. keskaliicola	Solitary or catenate	Obclavato-cylindrical to cylindrical	Mid olivaceous	64–164 × 16–28	Up to 17	On leaves of Hemidesmus indicus, India	[74]
C. laevistipitata	Solitary	Broadly ellipsoid	Red–brown	17.5–24 × 7–8	(0–)1–2 (–3)	On Pertusaria ophthalmiza (lichen), USA	[97]
C. lanneicola	Solitary	Obclavate	Straw-colored to brown	40–58 × 10–15	4–5	On dead branches of Lannea afzelii, Sierra Leone	[79]
C. lasianthi	Solitary	Obclavate, sometimes rostrate	Pale brown to dark brown	50–103.5 × 8.5–10	4–8	On dead branches of Lasianthus chinensis, China	[76]
C. leptoderridicola	Solitary	Obclavate, rostrate	Subhyaline to straw-colored	70–120 × 14–17	6–16	On dead branches of Leptoderris fasciculata, Sierra Leone	[79]
C. leucaenae	Solitary	Obclavate, obovoid or ellipsoid	Pale yellow	16–298 × 10–19	1–28	On leaves of Leucaena leucocephala, India	[70]
C. lignicola	Solitary or catenate	Cylindrical	Subhyaline to pale brown	110–156 × 7–9	–	On submerged decaying wood, China	[12]
C. ligustri	Solitary or catenate	Obclavate to cylindrical	Straw-colored to brown	25–225 × 7.5–30	4–20	On leaves of Ligustrum lucidum, China	[98]
C. litseae	Solitary	Obclavate	Pale brown to olivaceous brown	105–235 × 10–12	14–34	On dead branches of Litsea elongata, China	[99]
C. longispora	Solitary	Cylindrical	Subhyaline to pale brown	120–330 × 5.5–8	11–24	On dead herbaceous stems, India	[100]
C. maculiformis	Solitary or catenate	Cylindrical to obclavate	Subhyaline to pale olivaceous brown	20–86 × 5–10	2–8	On rotten wood, Czech Republic	[101]
“C. masseeanum”	Solitary	Elongate to obclavate	Pale olivaceous	80–120 × 18–20	7–11	On branches of Helicteres Isora, India	[31]
C. matuszakii	Solitary or catenate	Cylindrical to obclavate	Pale brown to straw-colored or mid brown	56–260 × 10–12.5	2–10	On herbaceous stems of Compositae, USA	[102]
C. merremiae	Solitary or catenate	Cylindrical to obclavate	Pale olivaceous brown to pale brown	37–150 × 6–12.5	4–22	On leaves of Merremia hirta, China	[98]
C. merrilliopanacis	Solitary	Obclavate, rostrate	Straw-colored to brown	130–260 × 17–21	12–25	On dead branches of Merrilliopanax listeri, China	[61]
C. micheliae	Solitary	Obclavate, rostrate	Subyhaline to brown	333–360 × 15–19	12–28	On dead branches of Michelia champaca, China	[61]
C. millettiae	Solitary or catenate	Obclavate, smooth	Olivaceous brown to mid brown	30–182 × 7.5–14	2–15	On leaves of Millettia, China	[98]
C. moracearum	Solitary	Obclavate to cylindrical	Light olivaceous brown	27–163 × 12–20	5–16	On living leaves of Ficus hispida, India	[103]
C. morindae-tinctoriae	Solitary	Obclavate	Pale olivaceous	44–127 × 15–26.5	6–15	On leaves of Morinda tinctoria, India	[104]
C. myrioneuronis	Solitary	Obclavate	Pale brown to brown	30–46 × 6.5–8	3–4	On dead branch of Myrioneuron faberi, China	[92]
C. mengsongensis	Solitary	Obclavate to cylindrical, rostrate	Brown to golden brown	96–146 × 16.5–20.5	13–18	On dead branches, China	This study
C. nana	Solitary	Obclavate	Subhyaline to pale olivaceous brown	49.5–110 × 9–18.5	4–14	On leaves of Lantana indica, India	[104]
C. nabanheensis	Solitary	Obclavate to cylindrical, expanded to a rounded shape at the apex	Pale brown to brown	56–84 × 12–14	9–13	On dead branches, China	This study
C. occidentalis	Solitary	Ovoid to ellipsoidal	Subyhaline to pale brown	30–54 × 15–19	3–6	On leaves of Cordia collococca, Cuba	[105]
C. palmicola	Solitary	Obclavate to subcylindrical	Pale brown	40–70 × 6–9	5–7	On leaves of Cocos australis, Paraguay	[106]
C. parapyrenariae	Solitary	Obclavate	Pale brown to brown	70–100 × 11–14	5–9	On dead branches of Parapyrenaria multisepala, China	[99]
C. parvispora	Solitary	Ovoid	Brown	13–15 × 4.5–7.5	1–2	On dead twigs of Gynotroches axillaris, Singapore	[81]
C. pedaliacearum	Solitary or catenate	Obclavato-cylindrical to slightly acicular	Pale olivaceous	16–163 × 3.2–6	3–28	On leaves of Sesamum indicum, India	[107]
C. peristrophicola	Solitary	Obclavate to obclavato-cylindrical	Olivaceous to very light brown	60–135 × 5–16	5–12	On leaves of Peristrophe bicalyculata, India	[80]
C. phylloshureae	Solitary	Obclavate	Brown	30–50 × 8–10	6–10	On dead branches of Phyllostachys sulphurea, China	[89]
C. pogostemonicola	Solitary	Obclavate to obclavato-cylindrical	Olivaceous to olivaceous brown	77–288 × 8–14	5–24	On leaves of Pogostemon plectrantoides, India	[108]
C. polyphragmia	Solitary or catenate	Obclavate	Pale to mid golden brown	110–280 × 14–17	10–25	On decorticated branches of Camellia japonica, Japan	[109]
C. pongamiicola	Solitary	Obclavate, ellipsoidal, clavate or club-shaped	Light olivaceous yellow	18–65.2 × 8–16.5	1–6	On living leaves of Pongamia pinnata, India	[110]
C. premnigena	Solitary or catenate	Obclavate to obclavato-cylindrical	Subhyaline to pale yellow	52–265 × 10–15	1–19	On leaves of Premna mucronata, India	[75]
C. proliferata	Solitary or catenate	Obclavate, rostrate	Pale brown to brown	30–300 × 9–12	3–17	On wood of Fagus sylvatica, the Netherlands	[111]
C. pruni	Solitary or catenate	Obclavate	Olivaceous brown or brown	50–130 × 10–16	4–9	On bark of Prunus serotina, USA	[27]
C. pseudocassiicola	Solitary	Subcylindrical to obclavate	Medium brown	95–160 × 9–10	(4–)8–12(–17)	On leaves of Byrsonima, Colombia	[112]
C. queenslandica	Solitary	Obclavate	Pale brown	72–114 × 8–10	6–9	On phyllodes of Acacia leiocalyx, Australia	[15]
C. rhapidis-humilis	Solitary	Obclavate, rostrate	Pale brown to olivaceous brown	90–130 × 6–8	12–16	On dead branches of Rhapis humilis, China	[94]
C. rhododendri	Solitary	Obclavate to long rostrate	Pale brown to olivaceous brown	180–400 × 7.5–11	19–36	On dead branches of Rhododendron hainanense, China	[113]
C. ripogoni	Solitary	Obclavate	Brown	60–160 × 10–13.5	7–15	On dead stems of Ripogonum scandens, New Zealand	[9]
C. rosacearum	Solitary or catenate	Obclavate to obclavato-cylindrical	Subhyaline to pale olivaceous brown	26.5–269 × 9–18.5	1–18	On leaves of Eriobotrya japonica, India	[104]
“C. ruelliae”	Solitary	Obclavate	Brown to pale olivaceous brown	60–150 × 12–15	5–16	On leaves of Ruellia macrophylla and Ruellia dipteracanthus, Singapore	[32]
C. sacchari	Solitary	Obclavate, rostrate, verrucose or smooth	Pale brown to olivaceous brown	80–120 × 8–9	10–14	On dead branches of Saccharum sinense, China	[114]
C. salasiae	Solitary	Ellipsoidal, doliiform	Brown	17–20 × 8–12	0–2	On dead stems of grass, Cuba	[115]
C. schleichericola	Solitary or catenate	Obclavate	Pale olivaceous brown	22.5–66 × 3.8–8.5	1–12	On leaves of Schleichera trijuga, India	[107]
C. scolopiae	Solitary	Obclavate	Pale brown to brown	90–150 × 10–13	8–11	On dead branches of Scolopia chinensis, China	[116]
C. sed-acaciae	Solitary	Obclavate	Pale brown to olivaceous brown	40–70 × 11–13.5	8–12	On dead branches of Acacia confusa, China	[113]
C. sidae	Solitary	Obclavate to obclavato-cylindrical	Olivaceous brown to very light brown	25–220 × 7–17	2–24	On leaves of Sida acuta, India	[117]
C. sinensis	Catenate	Obclavate or fusiform, ellipsoid	Brown	21–42 × 8–9.5	3(–4)	On dead branches, China	[13]
C. siwalika	Solitary	Obclavate, rostrate	Pale straw-colored to golden brown	88–140 × 15–20	9–19	On branches of Helicteres isora, India	[109]
C. smithii	Solitary or catenate	Cylindrical	Subhyaline to golden brown	70–410 × 12–19	7–45	On bark of Ilex, UK	[79]
C. solani	Solitary or catenate	Obclavate to cylindrical	Olivaceous yellow	80.6–276 × 8–10	1–17	On leaves of Solanum indicum, India	[118]
C. subcylindrica	Catenate	Broadly ellipsoid, subcylindrical	Pale brown	18–60(–90) × 5–13	0–3(–6)	On leaves of Lippia sidoides, Brazil	[63]
C. submersa	Solitary or catenate	Obclavate, rostrate	Subhyaline to golden brown	100–150 × 16–24	9–13	On submerged decaying wood, China	[12]
C. supkharii	Solitary	Obclavate	Pale olivaceous brown	22.5–142.5 × 10–17.5	2–11	On leaves of Phyllanthus parvifolius, India	[119]
C. tanaceti	Solitary	Obclavate, smooth or verruculose	Pale brown to olivaceous brown	60–104 × 12–16	7–12	On dead branches of Tanacetum vulgare, China	[116]
C. tectonae	Solitary	Obclavate, rostrate, verrucose or smooth	Pale brown to olivaceous brown	110–160 × 10–12	12–18	On dead branches of Tectona grandis, China	[114]
C. thailandica	Mostly solitary	Obclavate	Brown	80–110 × 10–12	4–8	On wood, Thailand	[120]
C. thorii	Catenate	Subcylindrical, broadly ellipsoid to almost obovoid	Pale brown to medium olivaceous brown	20–30 × 5–7	(0–)1(–3)	On thallus, apothecia of Lecanora, Japan	[121]
C. titarpaniensis	Solitary	Obclavate to cylindrical	Olivaceous brown to light brown	50–340 × 5–20	5–35	On living leaves of Lepidagathis, India	[122]
C. tomenticola	Solitary	Cylindrical	Olivaceous brown to brown	50–230 × 10.5–20.5	3–6	On living leaves of Terminalia tomentosa, India	[110]
C. toonae	Solitary	Obclavate, rostrate	Pale brown to dark brown	65–144 × 7–9	4–14	On dead branches of Toona sinensis, China	[114]
C. torulosa	Solitary	Clavate	Dark olivaceous brown	35–60 × 13–20	3–5	On dead leaves of Musa sapientum Brazil	[123]
C. tremae	Solitary	Obclavate to obclavato-cylindrical	Light brown to brown	50–160 × 4–12	5–20	On dead petiole of Trema orientalis, India	[124]
C. trematicola	Solitary	Obclavate to ellipsoid	Pale olivaceous brown	104–296 × 11–16	1–12	On leaves of Trema orientalis, India	[118]
C. trichiliae	Solitary	Obclavate, rostrate	Subhyaline to straw-colored	53–74 × 9–11	4–6	On branches of Trichilia heudelotii, Sierra Leone	[27]
C. trichoides	Solitary	Obclavato-cylindrical or obclavate	Pale olivaceous brown	29–170 × 10–15	3–14	On leaves of Triumfetta rhomboidea, Nepal	[87]
C. ulmacearum	Solitary	Obclavate	Subhyaline to pale olivaceous brown	15–106 × 3.5–10	2–16	On leaves of Trema orientalis, India	[107]
C. vismiae	Solitary or catenate	Obclavate, rostrate	Pale olivaceous brown or straw-colored	55–107 × 6–9	3–5	On leaves of Vismia guineensis, Sierra Leone	[85]
C. viticis	Solitary or catenate	Cylindrical	Pale brown	80–383 × 6–9	–	On leaves of Vitex rotundifolia, China	[98]
C. viticola	Solitary or catenate	Obclavate, cylindrical to obovoid	Pale olivaceous brown	34–170 × 7–17.5	1–14	On leaves of Cayratia carnosa, India	[118]
C. woodfordiana	Solitary or catenate	Obclavate, rostrate	Light olivaceous brown	40–170 × 9.5–17	4–14	On leaves of Woodfordia fruticosa, India	[71]
C. yerbae	Solitary or catenate	Obclavate	Subhyaline to pale golden brown	72–170 × 16–18	8–19	On dead branches of Ilex paraguayensis, Argentina	[26]
C. yunnanensis	Solitary	Obclavato-cylindrical, rostrate	Brown to golden brown	80–128 × 16–19	3–16	On dead branches, China	This study
C. ziziphae	Solitary	Obclavato-cylindrical, cylindrical or clavate	Mid olivaceous brown to straw-colored	33–215 × 10–27	Up to 15	On leaves of Ziziphus giraldii, India	[77]

All conidia are smooth, except where indicated; 2“–”, the number of septation is not given.

Kirschsteiniothelia is one genus of many lignicolous fungi encountered in aquatic and terrestrial habitats. Following the treatment of Sun et al. [38], the genus currently consists of 39 species including K. nabanheensis [38,62,66], but most species have been identified based on morphological studies, and to date, only 17 species are represented by DNA sequences in GenBank. Kirschsteiniothelia has mainly been reported in the USA (nine species), China (eight species) and Thailand (six species), and little published information is has been recorded in other regions [38,62,66]. Thus, it is unclear whether is closely related with geographic regions.

Studies conducted to date on Corynespora and Kirschsteiniothelia have mainly focused on their alpha taxonomy, and most knowledge of both genera is related to woody and herbaceous hosts, whereas we have a less developed understanding of many natural substrates, such as dung, insects and other fungi, including lichens. Because most species of both genera lack cultures, some of them may have received scant consideration in single-spore isolation before the advent of Sanger sequencing and even have particular substrate requirements. Similarly, little attention has been accorded to the roles of these genera in decomposition and nutrient recycling, their geographical distribution, substrate specificities and teleomorph relationships. Therefore, it is not yet possible to quantify their roles in ecosystem function. Although this study broadens our understanding of the diversity of Corynespora and Kirschsteiniothelia taxa, additional large-scale surveys of fungal resources in aquatic and terrestrial habitats within different geographic regions and with different ecological environments, host information and climatic conditions are needed, which will contribute to a comprehensive knowledge of the fungal diversity of these genera. Further collaboration will also be necessary to quantify their functional roles and strengthen our ability to conserve fungal resources.

Author Contributions

J.L., Y.H., X.L., J.X., Z.X. and J.M. designed the study and were involved in the writing of the paper. J.L. and X.S. were responsible for sample collections. J.L. and L.Z. were involved in phylogenetic analyses. R.F.C.-R., R.C. and J.M. contributed to planning and editing of the paper. All authors have read and agreed to the published version of the manuscript.

Institutional Review Board Statement

Not applicable.

Informed Consent Statement

Not applicable.

Data Availability Statement

All sequences generated in this study were submitted to GenBank.

Conflicts of Interest

The authors declare no conflict of interest.

Funding Statement

This project was supported by the National Natural Science Foundation of China (Nos. 32160006, 31970018, 31360011).