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Research Article
Morphology and phylogeny reveal two novel Coryneum species from China
expand article infoNing Jiang‡, Hermann Voglmayr§|, Cheng-Ming Tian‡
‡ Beijing Forestry University, Beijing, China
§ University of Natural Resources and Life Sciences, Vienna, Austria
| University of Vienna, Vienna, Austria

Corresponding author: Cheng-Ming Tian ( chengmt@bjfu.edu.cn )

Academic editor: Nalin Wijayawardene
© 2019 Ning Jiang, Hermann Voglmayr, Cheng-Ming Tian.
This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Citation: Jiang N, Voglmayr H, Tian C-M (2019) Morphology and phylogeny reveal two novel Coryneum species from China. MycoKeys 56: 67-80. https://doi.org/10.3897/mycokeys.56.35554
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Abstract

Coryneum is currently the sole genus of Coryneaceae in Diaporthales, distinguished from other diaporthalean genera by transversely distoseptate brown conidia. However, Coryneum species are presently difficult to identify because of variability and overlap of morphological characters and the lack of sequence data for most described species. During fungal collection trips in China, 13 Coryneum isolates were obtained from cankered branches of Ilex and Quercus. Morphological and phylogenetic analyses (ITS, LSU, TEF1-α and RPB2) revealed that these strains belong to two new species (viz. Coryneum ilicis sp. nov. and C. songshanense sp. nov.), and three known species, C. gigasporum, C. sinense, and C. suttonii. Coryneum ilicis has larger conidia and more distosepta than most Coryneum species. Coryneum songshanense was similar to C. sinense from the same host genus, Quercus, in conidial length, but distinct in conidial width and by molecular data.

Keywords

Coryneaceae, Diaporthales, systematics, taxonomy

Introduction

The genus Coryneum Nees is currently the only accepted genus in Coryneaceae and it forms a distinct phylogenetic lineage in Diaporthales (Senanayake et al. 2017, 2018, Voglmayr et al. 2017, Fan et al. 2018a, Jiang et al. 2018, Senwanna et al. 2018, Wijayawardene et al. 2017, 2018). The genus Coryneum was introduced based on the asexual morph, with C. umbonatum Nees as the type species (Nees von Esenbeck 1816), and the sexual morph Pseudovalsa Ces. & De Not. was introduced later, based on P. lanciformis (Fr.) Ces. & De Not. (Cesati & De Notaris 1863). Coryneum was recommended to be adopted due to priority and the need of fewer new combinations (Rossman et al. 2015).

Most Coryneum species were considered as phytopathogens, which were discovered from cankers and dieback of shoots and twigs (Wijayawardene et al. 2016, Senanayake et al. 2017, Jiang et al. 2018). However, diseases are commonly mild and only rarely cause serious symptoms in the hosts. Additionally, pathogenicity tests have not yet been conducted.

Coryneum species are generally considered highly host-specific, and 28 species and a variety were accepted in this genus before this study (Sutton 1975, 1980, Wijayawardene et al. 2016, Jiang et al. 2018, Senwanna et al. 2018). Coryneum terrophilum was the only species isolated from soil, and the others were reported from dead branches (Table 1). Fagales species are the major hosts of Coryneum species, and host trees from other orders are also hardwoods with rough barks (Table 1).

Table 1.
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Hosts, conidial sizes, and numbers of distosepta of currently accepted Coryneum species.

Species Host genus Host family Host order Conidial size (μm) No. of distosepta References
C. arausiacum Quercus Fagaceae Fagales 42–56 × 13–16 4–5 Senanayake et al. (2017)
C. betulinum Betula Betulaceae Fagales 31–36 × 14–17 4–5 Sutton (1975)
C. calophylli Calophyllum Guttiferae Parietales 38–48 × 12.5–14.5 5–6 Sutton (1975)
C. carpinicola Carpinus Betulaceae Fagales 50–68 × 8–11 7–11 Sutton (1975)
C. castaneicola Castanea Fagaceae Fagales 56–80 × 9.5–13 5–8 Sutton (1975)
C. cesatii Aesculus Hippocastanaceae Sapindales 80–90 × 13–15 6–7 Sutton (1975)
C. clusiae Clusia Clusiaceae Malpighiales 30–40 × 20–30 3–5 Sutton (1975)
C. compactum Ulmus Ulmaceae Urticales 40–58 × 15–21 4–6 Sutton (1975)
C. depressum Quercus Fagaceae Fagales 44–53 × 19–23 4–6 Sutton (1975)
C. elevatum Quercus Fagaceae Fagales 56–69 × 24–28 5–7 Sutton (1975)
C. gigasporum Castanea Fagaceae Fagales 88–117 × 18–23 7–9 Jiang et al. (2018)
C. gregoryi Eucalyptus Myrtaceae Myrtales 32.5–43 × 12–16 5–9 Sutton and Sharma (1983)
C. heveanum Hevea Euphorbiaceae Malpighiales 40–68 × 14–20 4–6 Senwanna et al. (2018)
C. ilicis Ilex Aquifoliaceae Sapindales 82–105 × 9.5–12.5 10–11 This study
C. japonicum Quercus Fagaceae Fagales 45–60 × 11–12 5–7 Sutton (1975)
C. lanciforme Betula Betulaceae Fagales 45–53 × 16–18 4–6 Sutton (1975)
C. megaspermum Quercus Fagaceae Fagales 73–97 × 13–16 7–11 Sutton (1980)
C. megaspermum var. cylindricum Quercus Fagaceae Fagales 100–125 × 10–13 7–8 Sutton (1975)
C. modonium Castanea Fagaceae Fagales 50–71 × 14–19 5–8 Sutton (1975)
C. neesii Quercus Fagaceae Fagales 68–82 × 18–22 6–8 Sutton (1975)
C. pruni Prunus Rosaceae Rosales 14–23 × 5.5–9 4–5 Wijayawardene et al. (2016)
C. psidii Psidium Myrtaceae Myrtales 25–40 × 14–17 5–6 Sutton (1975)
C. pyricola Pyrus Rosaceae Rosales 61–70 × 24–32 5–7 Sutton (1975)
C. quercinum Quercus Fagaceae Fagales 45–60 × 14–16 6–7 Muthumary and Sutton (1986)
C. sinense Quercus Fagaceae Fagales 50–76 × 13–17 5–7 Jiang et al. (2018)
C. songshanense Quercus Fagaceae Fagales 51–76 × 9–11.5 5–7 This study
C. stromatoideum Tsuga Pinaceae Pinales 105–180 × 16–20 9–17 Sutton (1975)
C. suttonii Castanea Fagaceae Fagales 60–76 × 10–14.5 4–5 Jiang et al. (2018)
C. sydowianum Alnus Betulaceae Fagales 50–58 × 14–17 5–6 Sutton (1975)
C. terrophilum NA NA NA 25–55 × 15–24 3–7 Sutton and Sharma (1983)
C. umbonatum Quercus Fagaceae Fagales 57–72 × 13–16 5–7 Sutton (1975)

Molecular phylogenies based on multi-gene loci including the internal transcribed spacer (ITS) and the large subunit (LSU) regions of the nuclear rDNA, translation elongation factor-1α (TEF1-α) and the second largest subunit of the RNA polymerase II (RPB2) have been widely used to infer species delimitation within many genera in Diaporthales (Voglmayr et al 2012, 2017, 2019, Voglmayr and Jaklitsch 2014, Fan et al. 2018b, Jiang et al. 2019), and are particularly important in speciose genera like Coryneum. Hence, DNA extraction from known species and fresh collections from the potential hosts will greatly improve the elucidation of species concept and circumscription in Coryneum. Thus, the main objectives of the present study were to identify Coryneum taxa based on morphology and phylogenetic evidence, and to analyse the relationships between Coryneum species and host genera.

Materials and methods

Sample collection and isolation

Sample collection trips were conducted in Beijing, Hebei and Shaanxi Provinces of China during June to October in 2017 and 2018, aiming to collect fresh specimens with Coryneum–like taxa. Fagales plants were the main hosts and other hardwoods with rough barks were also investigated. Healthy branches and twigs were covered by green leaves, hence the dying and dead materials were conspicuous during our investigations. Asexual fruiting bodies were easily discovered as black spots on the host barks. Tree tissues with fruiting bodies were cut into small pieces, packed in paper bags and taken to the laboratory for further studies. Isolations were obtained by removing the ascospores or conidial masses from the fruiting bodies on to clean potato dextrose agar (PDA) plates, which were incubated at 25 °C until spores germinated. Single germinating spores were transferred on to new PDA plates, which were kept at 25 °C in the dark. Specimens were deposited at the Museum of the Beijing Forestry University (BJFC) and axenic cultures are maintained at the China Forestry Culture Collection Centre (CFCC).

Morphological analysis

Species identification was based on the morphological characters of the sexual and asexual morphs produced on natural substrates. Cross-sections were prepared manually using a double-edged blade under a Leica stereomicroscope (M205 FA). Photomicrographs were captured with a Nikon Eclipse 80i microscope equipped with a Nikon digital sight DS-Ri2 high-definition colour camera, using differential interference contrast (DIC) illumination and the Nikon software, NIS-Elements D Package 3.00. Measurements of ascospores and conidia are reported as the maximum and minimum in parentheses and the range representing the mean ± standard deviation of the number of measurements is given in parentheses (Voglmayr et al. 2017). Cultural characteristics of isolates incubated on MEA in the dark at 25 °C were recorded.

Recognition and identification of Coryneum species were based on fruiting bodies formed on tree bark, supplied by conidiomata produced on PDA plates. Ascomata and conidiomata from tree bark were sectioned by hand using a double-edged blade, and conidiomata from PDA plates were picked using a needle, which were observed under a dissecting microscope. At least 10 conidiomata/ascomata, 10 asci, and 50 conidia/ascospores were measured to calculate the mean sizes and standard deviation. Microscopy photographs were captured with a Nikon Eclipse 80i compound microscope equipped with a Nikon digital sight DS-Ri2 high definition colour camera, using differential interference contrast illumination.

DNA extraction, PCR amplification and sequencing

Genomic DNA was extracted from colonies grown on cellophane-covered PDA plates using a modified CTAB method (Doyle and Doyle 1990). PCR amplifications were performed in a DNA Engine Peltier Thermal Cycler (PTC-200; Bio-Rad Laboratories, Hercules, CA, USA). The primer sets ITS1/ITS4 (White et al. 1990) were used to amplify the ITS region. The primer pair LR0R/LR5 (Vilgalys and Hester 1990) was used to amplify the LSU region. The primer pairs EF1-688F/EF1-986R or EF1-728F/TEF1-LLErev (Carbone and Kohn 1999, Jaklitsch et al. 2006, Alves et al. 2008) were used to amplify TEF1-α gene. The primer pair dRPB2-5f/dRPB2-7r (Voglmayr et al. 2016) was used to amplify the RPB2 gene. The polymerase chain reaction (PCR) assay was conducted as described by Fan et al. (2018a). PCR amplification products were assayed via electrophoresis in 2 % agarose gels. DNA sequencing was performed using an ABI PRISM® 3730XL DNA Analyzer with a BigDye Terminater Kit v.3.1 (Invitrogen, USA) at the Shanghai Invitrogen Biological Technology Company Limited (Beijing, China). Novel sequences generated in the current study were deposited in GenBank (Table 2).

Table 2.
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Strains used in the phylogenetic tree and their culture accession and GenBank numbers. Strains from this study are in bold.

Species Strains GenBank numbers
ITS LSU TEF1-α RPB2
Coryneum castaneicola CFCC 52315 MH683551 MH683559 MH685731 MH685723
Coryneum castaneicola CFCC 52316 MH683552 MH683560 MH685732 MH685724
Coryneum depressum D202 MH674330 MH674330 MH674338 MH674334
Coryneum heveanum MFLUCC 17-0369 MH778707 MH778703 MH780881 NA
Coryneum heveanum MFLUCC 17-0376 MH778708 MH778704 NA NA
Coryneum gigasporum CFCC 52319 MH683557 MH683565 MH685737 MH685729
Coryneum gigasporum CFCC 52320 MH683558 MH683566 MH685738 MH685730
Coryneum gigasporum G14 MK799957 MK799944 MK799830 MK799820
Coryneum gigasporum G15 MK799958 MK799945 MK799831 MK799821
Coryneum ilicis CFCC 52994 MK799948 MK799935 NA NA
Coryneum ilicis CFCC 52995 MK799949 MK799936 NA NA
Coryneum ilicis CFCC 52996 MK799950 MK799937 NA NA
Coryneum lanciforme D215 MH674332 MH674332 MH674340 MH674336
Coryneum modonium D203 MH674331 MH674331 MH674339 MH674335
Coryneum modonium CBS 130.25 MH854812 MH866313 NA NA
Coryneum sinense CFCC 52452 MH683553 MH683561 MH685733 MH685725
Coryneum sinense CFCC 52453 MH683554 MH683562 MH685734 MH685726
Coryneum sinense X20 MK799952 MK799939 MK799825 MK799815
Coryneum sinense X23 MK799953 MK799940 MK799826 MK799816
Coryneum sinense X60 MK799951 MK799938 MK799824 MK799814
Coryneum songshanense CFCC 52997 MK799946 MK799933 MK799822 MK799812
Coryneum songshanense CFCC 52998 MK799947 MK799934 MK799823 MK799813
Coryneum suttonii CFCC 52317 MH683555 MH683563 MH685735 MH685727
Coryneum suttonii CFCC 52318 MH683556 MH683564 MH685736 MH685728
Coryneum suttonii Z15-1 MK799954 MK799941 MK799827 MK799817
Coryneum suttonii Z17 MK799955 MK799942 MK799828 MK799818
Coryneum suttonii Z86 MK799956 MK799943 MK799829 MK799819
Coryneum umbonatum D201 MH674329 MH674329 MH674337 MH674333

Phylogenetic analyses

Sequences generated from the above primers of the different genomic regions (ITS, LSU, TEF1-α and RPB2) were analysed in comparison to known species, Stilbospora macrosperma (CBS 115073) and Stegonsporium pyriforme (CBS 120522) were used as the outgroup taxa (Jiang et al. 2018). All sequences were aligned using MAFFT v. 6 (Katoh and Toh 2010) and edited manually using MEGA v. 6 (Tamura et al. 2013). Phylogenetic analyses were performed using PAUP v. 4.0b10 for maximum parsimony (MP) analysis (Swofford 2003), and PhyML v. 3.0 for Maximum Likelihood (ML) analysis (Guindon et al. 2010).

A partition homogeneity test with heuristic search and 1000 replicates was performed using PAUP v. 4.0b10 to assess incongruence among the ITS, LSU, TEF1-α, and RPB2 sequence datasets in reconstructing phylogenetic trees. MP analysis was run using a heuristic search option of 1000 search replicates with random-addition of sequences with a tree bisection and reconnection (TBR) algorithm; branches of zero length were collapsed (collapse = minbrlen), and all equally most parsimonious trees were saved. Other calculated parsimony scores were tree length (TL), consistency index (CI), retention index (RI), and rescaled consistency (RC). ML analysis was performed using a GTR site substitution model, including a gamma-distributed rate heterogeneity and a proportion of invariant sites (Guindon et al. 2010). The branch support was evaluated using a bootstrapping method of 1000 bootstrap replicates (Hillis and Bull 1993). The MP bootstrap analyses were done with the same settings as for the heuristic search, but with 10 rounds of heuristic search during each bootstrap replicate. Phylograms were shown using FigTree v. 1.4.3 (Rambaut 2016).

Results

Phylogenetic analyses

The alignment based on the combined sequence dataset (ITS, LSU, TEF1-α, and RPB2) included 30 ingroup taxa and two outgroup taxa (Stilbospora macrosperma and Stegonsporium pyriforme), comprising 3544 characters in the aligned matrix. Of these, 2570 characters were constant, 267 variable characters were parsimony-uninformative and 706 characters were parsimony informative. The partition homogeneity test resulted in an insignificant value (level 95%), indicating that ITS, LSU, TEF1-α and RPB2 sequence dataset could be combined. The MP analysis resulted in 2 equally most parsimonious trees; the first tree (TL = 1624, CI = 0.784, RI = 0.822, RC = 0.645) is shown in Fig. 1. The two MP trees were identical, except for an interchanged position of C. ilicis and C. songshanense (not shown). Tree topology of the best tree revealed by the ML analyses was identical to that of the MP tree shown. The phylogram based on the four gene sequences showed that the accessions here studied represented 2 new and 3 known species in Coryneum (Fig. 1).

Figure 1. 

Phylogenetic tree based on an MP analysis of a combined DNA dataset of ITS, LSU, TEF1-α and RPB2 gene sequences for the species of Coryneum. Bootstrap values ≥ 50 % for MP/ML analyses are presented at the branches. Scale bar = 50 nucleotide substitutions.

Taxonomy

Coryneum ilicis C.M. Tian & N. Jiang, sp. nov.

MycoBank No: 830201
Figure 2

Diagnosis

Coryneum ilicis is characterised by its host, Ilex pernyi, and large conidia with 10–11 distosepta.

Holotype

CHINA. Shaanxi Province: Zhashui County, on branches of Ilex pernyi, 12 August 2017, N. Jiang (holotype: BJFC-S1720; ex-type culture from ascospore: CFCC 52994; living culture from conidium: CFCC 52996).

Etymology

Named after the host genus on which it was collected, Ilex.

Description

Associated with canker on branches of Ilex pernyi. Sexual morph: Pseudostromata 0.5–1.5 mm diam., typically distinct, circular, without perithecial bumps, containing 1 or 2 perithecia embedded in a well-developed entostroma. Central column and entostroma grey. Ostioles inconspicuous and often invisible at the surface of the ectostromatic disc. Perithecia (350–)500–700(–850) μm diam. (n = 20), globular, somewhat flattened at the base. Asci 110–155 × 13–20 μm, 8-spored, unitunicate, clavate, shortly pedicellate, apically rounded, with a conspicuous apical ring. Ascospores (26.2–)29.7–35.5(–36.2) × (11.0–)11.8–14.3(–15.2) μm, l/w = (1.9–)2.2–2.9(–3.2) (n = 50), 1-seriate, fusiform, ends pointed, uniseptate, constricted at the septa, hyaline, guttulate, smooth-walled. Asexual morph: Conidiomata acervular, 0.2–1 mm wide, 0.2–1.2 mm high, solitary, erumpent through the outer periderm layers of the host, scattered, surface tissues above slightly domed. Conidiophores 40–85 μm long, 3–7 μm wide, branched, cylindrical, septate, hyaline at the apex, pale brown at the base. Conidiogenous cells holoblastic, integrated, indeterminate, cylindrical, expanding towards the apices, pale brown, smooth, with 0–1 percurrent extensions. Conidia (82–)87–95(–105) × (9.5–)10.5–11.5(–12.5) μm, l/w = (7.4–)7.7–9.1(–9.3) (n = 50), variable in shape, curved, broadly fusiform to fusiform, cylindrical or clavate, dark brown, smooth-walled, 10–11-distoseptate, apical cell with a hyaline tip, truncate and black at the base.

Figure 2. 

Coryneum ilex from Ilex pernyi (BJFC-S1720, holotype) A Fruiting bodies on natural substrate in surface view B pseudostroma in transverse section, showing perithecia and gray entostroma C longitudinal sections through pseudostromata D ascus E–J ascospores K conidiophores L–N conidia. Scale bars: 1 mm (A); 0.5 mm (B, C); 20 μm (D); 10 μm (E–N).

Culture characters

On PDA at 25 °C, colonies growing slowly and unevenly, reaching 70 mm diam. within 25 d, gradually becoming brownish dark grey in colour with scant cottony aerial mycelium, asexual morphs developed after 35 d.

Additional specimen examined

CHINA. Shaanxi Province: Zhashui County, on branches of Ilex pernyi, 12 August 2017, N. Jiang (isotype: BJFC-S1721; living culture: CFCC 52995).

Notes

Coryneum ilicis is the sole species known from the host genus Ilex; it can be easily recognised by host association and phylogeny (Fig. 1). Morphologically, conidia of Coryneum ilicis are larger and have more distosepta than in most of the other species (Table 1).

Coryneum songshanense C.M. Tian & N. Jiang, sp. nov.

MycoBank No: 830202
Figure 3

Diagnosis

Coryneum songshanense can be distinguished from the morphologically similar C. sinense by its narrower conidia.

Holotype

CHINA. Beijing City: Songshan Mountain, on dead twigs of Quercus dentata, 15 June 2018, N. Jiang & C.M. Tian (holotype: BJFC-S1722; ex-type culture from ascospore: CFCC 52997).

Etymology

Named after the mountain on which it was collected, Songshan Mountain.

Description

Associated with canker on twigs of Quercus dentata. Sexual morph: Pseudostromata 0.3–1 mm diam., typically distinct, circular, without perithecial bumps, containing up to 6 perithecia embedded in a well-developed entostroma. Ectostromatic disc distinct, circular, black, 0.3–0.5 mm diam. Central column and entostroma grey. Ostioles inconspicuous and often invisible at the surface of the ectostromatic disc. Perithecia (150–)200–450(–550) μm diam. (n = 20), globular, somewhat flattened at the base with black short neck. Asci 75–145 × 17–23 μm, 8-spored, unitunicate, clavate, shortly pedicellate, apically rounded, with an inconspicuous apical ring. Ascospores (24.1–)25.5–35.4(–38.2) × (7.5–)7.9–9.8(–10.6) μm, l/w = (3.0–)3.3–3.8(–4.2) (n = 50), 2-seriate, fusiform, ends pointed, uniseptate or aseptate, not constricted at the septa, hyaline, guttulate, smooth-walled. Asexual morph: Conidiomata acervular, 0.2–0.6 mm wide, 0.2–0.5 mm high, solitary, erumpent through the outer periderm layers of the host, scattered, surface tissues above slightly domed. Conidiophores 15–35 μm long, 4–7 μm wide, unbranched, cylindrical, septate, hyaline at the apex, pale brown at the base. Conidiogenous cells holoblastic, integrated, indeterminate, cylindrical, expanding towards the apices, pale brown, smooth, with 0–1 percurrent extensions. Conidia (51–)56–67(–76) × (9–)10–11(–11.5) μm, l/w = (5.2–)5.5–6.9(–8.1) (n = 50), variable in shape, curved, broadly fusiform to fusiform, cylindrical or clavate, dark brown, smooth-walled, 5–7-distoseptate, apical cell with a hyaline tip, truncate and black at the base.

Figure 3. 

Coryneum songshanense from Quercus dentata (BJFC-S1722, holotype) A, B Fruiting bodies on natural substrate in surface view C pseudostroma in transverse section, showing perithecia and gray entostroma D longitudinal sections through pseudostromata E, F immature asci G, H immaure Ascospores I, J conidiophores K–M conidia. Scale bars: 1 mm (A, B); 0.5 mm (C, D); 10 μm (E–M).

Culture characters

On PDA at 25 °C, colonies growing slowly and unevenly, reaching 70 mm diam. within 30 d, gradually becoming brownish dark grey in colour with scant cottony aerial mycelium, asexual morphs developed after 40 d.

Additional specimen examined

CHINA. Beijing City: Songshan Mountain, on dead twigs of Quercus dentata, 15 June 2018, N. Jiang & C.M. Tian (isotype: BJFC-S1723; living culture from conidium: CFCC 52998).

Notes

So far, ten species and one variety have been described from Quercus branches, and they can be distinguished by conidial characteristics (Muthumary and Sutton 1986, Jiang et al. 2018, Table 1). Coryneum songshanense and C. sinense can be distinguished from C. arausiacum, C. depressum, C. elevatum, C. japonicum, C. megaspermum, C. megaspermum var. cylindricum, C. neesii, C. umbonatum, and C. quercinum by unbranched conidiophores (Sutton 1975, Muthumary and Sutton 1986, Jiang et al. 2018). Coryneum songshanense is obviously distinguished from C. sinense in narrower conidia (9–11.5 μm in Coryneum songshanense vs. 13–17 μm in C. sinense) and phylogeny (Fig. 1).

Discussion

In this study, fresh Coryneum specimens were collected in China and identified based on combined morphological amd molecular data. Additional accessions of three recently described Coryneum species, C. gigasporum, C. sinense, and C. suttonii (Jiang et al. 2018), were identified, with matching conidial characteristics and sequences (Fig. 1). The new species C. ilicis was discovered on Ilex pernyi (Aquifoliaceae, Sapindales), which represents a new host family and genus for Coryneum. Coryneum cesatii was reported from the same host order, Sapindales, on branches of Aesculus (Hippocastanaceae) (Sutton 1975). The second new species, Coryneum songshanense, was discovered on dead twigs of Quercus dentata (Fagaceae, Fagales). Host species belonging to Fagales show higher diversity of Coryneum species (Table 1), and it is likely that additional taxa will be discovered by molecular data, considering that in many regions suitable hosts have not yet been adequately studied.

However, most of the Coryneum species are lacking DNA sequences, thus species identification based on DNA sequence analyses is presently difficult. Hence, polyphasic approach, i.e. incorporating morphological characters (such as conidial sizes and numbers of distosepta), as well as host associations are important for species identification (Sutton 1975, 1980, Jiang et al. 2018). However, host identifications may be incorrect and many geographical areas remain insufficiently studied. In addition, the morphological characters often significantly overlap between species, which makes identifications solely by morphology challenging. Hence, studies based on the types of already described species and new collections from potential hosts are important to achieve a reliable species classification and circumscription within Coryneum.

Acknowledgements

This study was financed by the National Natural Science Foundation of China (Project No.: 31670647) and the Short-term International Student Program for Postgraduates of Forestry First-Class Discipline (2019XKJS0501). Financial support from the Austrian Science Fund (FWF; project P27645-B16) to H. Voglmayr is gratefully acknowledged. We are grateful to Chungen Piao and Minwei Guo (China Forestry Culture Collection Center (CFCC), Chinese Academy of Forestry, Beijing) for support with strain preservation during this study.

References

  • Alves A, Crous PW, Correia A, Phillips AJL (2008) Morphological and molecular data reveal cryptic speciation in Lasiodiplodia theobromae. Fungal Diversity 28: 1–13.
  • Carbone I, Kohn LM (1999) A method for designing primer sets for speciation studies in filamentous ascomycetes. Mycologia 91: 553–556. https://doi.org/10.2307/3761358
  • Cesati V, De Notaris G (1863) Schema di classificazione degle sferiacei italici aschigeri piu’ o meno appartenenti al genere Sphaeria nell’antico significato attribuitoglide Persono. Commentario della Società Crittogamologica Italiana 1: 177–420.
  • Guindon S, Dufayard JF, Lefort V, Anisimova M, Hordijk W, Gascuel O (2010) New algorithms and methods to estimate maximum-likelihood phylogenies: assessing the performance of PhyML 3.0. Systematic Biology 59: 307–321. https://doi.org/10.1093/sysbio/syq010
  • Hillis DM, Bull JJ (1993) An empirical test of bootstrapping as a method for assessing confidence in phylogenetic analysis. Systematic Biology 42: 182–192. https://doi.org/10.1093/sysbio/42.2.182
  • Jaklitsch WM, Komon M, Kubicek CP, Druzhinina IS (2006) Hypocrea voglmayrii sp. nov. from the Austrian Alps represents a new phylogenetic clade in Hypocrea/Trichoderma. Mycologia 97: 1365–1378. https://doi.org/10.1080/15572536.2006.11832743
  • Jiang N, Fan XL, Crous PW, Tian CM (2019) Species of Dendrostoma (Erythrogloeaceae, Diaporthales) associated with chestnut and oak canker diseases in China. Mycokeys 48: 67–96. https://doi.org/10.3897/mycokeys.48.31715
  • Rambaut A (2016) FigTree, version 1.4.3. University of Edinburgh, Edinburgh.
  • Rossman AY, Adams GC, Cannon PF, Castlebury LA, Crous PW, Gryzenhout M, Jaklitsch WM, Mejia LC, Stoykov D, Udayanga D, Voglmayr H, Walker DM (2015) Recommendations of generic names in Diaporthales competing for protection or use. IMA Fungus 6: 145–154. https://doi.org/10.5598/imafungus.2015.06.01.09
  • Senanayake IC, Crous PW, Groenewald JZ, Maharachchikumbura SSN, Jeewon R, Phillips AJL, Bhat JD, Perera RH, Li QR, Li WJ, Tangthirasunun N, Norphanphoun C, Karunarathna SC, Camporesi E, Manawasighe IS, Al-Sadi AM, Hyde KD (2017) Families of Diaporthales based on morphological and phylogenetic evidence. Studies in Mycology 86: 217–296. https://doi.org/10.1016/j.simyco.2017.07.003
  • Senanayake IC, Jeewon R, Chomnunti P, Wanasinghe DN, Norphanphoun C, Karunarathna A, Pem D, Perera RH, Camporesi E, McKenzie EHC, Hyde KD, Karunarathna SC (2018) Taxonomic circumscription of Diaporthales based on multigene phylogeny and morphology. Fungal Diversity 93: 241–443. https://doi.org/10.1007/s13225-018-0410-z
  • Senwanna C, Hyde KD, Phookamsak R, Jones EG, Cheewangkoon R (2018) Coryneum heveanum sp. nov. (Coryneaceae, Diaporthales) on twigs of Para rubber in Thailand. Mycokeys 43: 75–90. https://doi.org/10.3897/mycokeys.43.29365
  • Sutton BC (1975) Coelomycetes V. Coryneum. Mycological Papers 138: 1–224.
  • Sutton BC (1980) The Coelomycetes: Fungi Imperfect With Pycnidia, Acervuli and Stromata. Commonwealth Mycological Institute, Kew.
  • Swofford DL (2003) PAUP*: Phylogenetic Analyses Using Parsimony, * and Other Methods, Version 4.0b10. Sinauer Associates, Sunderland.
  • Tamura K, Stecher G, Peterson D, Filipski A, Kumar S (2013) MEGA6: Molecular Evolutionary Genetics Analysis version 6.0. Molecular Biology and Evolution 30: 2725–2729. https://doi.org/10.1093/molbev/mst197
  • Voglmayr H, Akulov OY, Jaklitsch WM (2016) Reassessment of Allantonectria, phylogenetic position of Thyronectroidea, and Thyronectria caraganae sp. nov. Mycological Progress 15: 921–937. https://doi.org/10.1007/s11557-016-1218-4
  • Voglmayr H, Castlebury LA, Jaklitsch WM (2017) Juglanconis gen. nov. on Juglandaceae, and the new family Juglanconidaceae (Diaporthales). Persoonia 38: 136–155. https://doi.org/10.3767/003158517X694768
  • Voglmayr H, Rossman AY, Castlebury LA, Jaklitsch W (2012) Multigene phylogeny and taxonomy of the genus Melanconiella (Diaporthales). Fungal Diversity 57: 1–44. https://doi.org/10.1007/s13225-012-0175-8
  • Vilgalys R, Hester M (1990) Rapid genetic identification and mapping of enzymatically amplified ribosomal DNA from several Cryptococcus species. Journal of Bacteriology 172: 4238–4246. https://doi.org/10.1128/jb.172.8.4238-4246.1990
  • White TJ, Bruns T, Lee S, Taylor JM (1990) Amplification and direct sequencing of fungal ribosomal RNA genes for phylogenetics. In: Innis MA, Gelfand DH, Sninsky JJ, White TJ (Eds) PCR protocols: A Guide to the Methods and Applications. Academic Press, New York, 315–322. https://doi.org/10.1016/B978-0-12-372180-8.50042-1
  • Wijayawardene NN, Hyde KD, Rajeshkumar KC, Hawksworth DL, Madrid H, Kirk PM, Braun U, Singh RV, Crous PW, Kukwa M, Lücking R, Kurtzman CP, Yurkov A, Haelewaters D, Aptroot A, Lumbsch HT, Timdal E, Ertz D, Etayo J, Phillips AJL, Groenewald JZ, Papizadeh M, Selbmann L, Dayarathne MC, Weerakoon G, Gareth Jones EB, Suetrong S, Tian Q, Castañeda-Ruiz RF, Bahkali AH, Pang K, Tanaka K, Dai DQ, Sakayaroj J, Hujslová M, Lombard L, Shenoy BD, Suija A, Maharachchikumbura SSN, Thambugala KM, Wanasinghe DN, Sharma DO, Gaikwad S, Pandit G, Zucconi L, Onofri S, Egidi E, Raja HA, Kodsueb R, Cáceres MES, Pérez-Ortega S, Fiuza PO, Monteiro JS, Vasilyeva LN, Shivas RG, Prieto M, Wedin M, Olariaga I, Lateef AA, Agrawal Y, Fazeli SAS, Amoozegar MA, Zhao GZ, Pfliegler WP, Sharma G, Oset M, Abdel-Wahab MA, Takamatsu S, Bensch K, de Silva NI, De Kesel A, Karunarathna A, Boonmee S, Pfister DH, Lu Y, Luo Z, Boonyuen N, Daranagama DA, Senanayake IC, Jayasiri SC, Samarakoon MC, Zeng X, Doilom M, Quijada L, Rampadarath S, Heredia G, Dissanayake AJ, Jayawardana RS, Perera RH, Tang LZ, Phukhamsakda C, Hernández-Restrepo M, Ma X, Tibpromma S, Gusmao LFP, Weerahewa D, Karunarathna SC (2017) Notes for genera: Ascomycota. Fungal Diversity 86: 1–594. https://doi.org/10.1007/s13225-017-0386-0
  • Wijayawardene NN, Hyde KD, Lumbsch HT, Liu JK, Maharachchikumbura SSN, Ekanayaka AH, Tian Q, Phookamsak R (2018) Outline of Ascomycota: 2017. Fungal Diversity 88: 167–263. https://doi.org/10.1007/s13225-018-0394-8
  • Wijayawardene NN, Hyde KD, Wanasinghe DN, Papizadeh M, Goonasekara ID, Camporesi E, Bhat DJ, McKenzie EHC, Phillips AJL, Diederich P, Tanaka K, Li WJ, Tangthirasunun N, Phookamsak R, Dai DQ, Dissanayake AJ, Weerakoon G, Maharachchikumbura SSN, Hashimoto A, Matsumura M, Bahkali Wang Y (2016) Taxonomy and phylogeny of dematiaceous coelomycetes. Fungal Diversity 77: 1–136. https://doi.org/10.1007/s13225-016-0360-2
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