Research Article |
Corresponding author: Cheng-Ming Tian ( chengmt@bjfu.edu.cn ) Academic editor: Kevin D. Hyde
© 2019 Ning Jiang, 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, Tian C-M (2019) Re-collection of Dermea prunus in China, with a description of D. chinensis sp. nov. MycoKeys 50: 79-91. https://doi.org/10.3897/mycokeys.50.32517
|
Dermea was protected against its synonym, Foveostroma, due to its well-circumscribed generic concept and more frequent use. We describe and illustrate Dermea chinensis sp. nov. based on its morphological characteristics and a molecular analysis of the internal transcribed spacer (ITS) and large subunit (LSU) sequence data. Dermea chinensis is isolated from Betula albosinensis with sexual and asexual morphs and can be distinguished from D. molliuscula on Betula trees by its aseptate and wider ascospores. The connection between the two morphs is proved based on sequence data. Here, we describe the asexual morph of D. pruni for the first time based on morphological and molecular data from the same host and country of origin, and compare it with other species of Prunus.
Betula, Dermateaceae, new species, Prunus
Dermea Fr. (Dermateaceae, Helotiales) was first proposed based on D. cerasi (Fries, 1825), which is the sexual Asexual morph of the type species of Micropera Lév. (Léveillé, 1846) and Foveostroma DiCosmo (
Dermea is a well-characterized genus with hard, leathery, dark brown to black apothecia; cylindrical to clavate-cylindrical, usually eight-spored asci; and ellipsoid-fusiform to ellipsoidal, hyaline to yellowish-brown, aseptate to 3-septate ascospores (
Dermea species are generally considered highly host-specific (
Dermea species were considered pathogenic to their hosts (
During our fungal collection surveys conducted in China, we collected several Dermea specimens from two species of tree, Betula albosinensis and Prunus cerasifera f. atropurpurea. We identified fungi species using both morphological and molecular approaches; as a result, a novel species and the asexual Asexual morph of D. pruni are described herein for the first time.
Fresh specimens of Dermea were collected from tree barks during our fungal collection trip in China. We obtained single ascospore and conidia isolates by removing a mucoid spore mass from apothecia or conidiomata and spreading the suspension on the surface of 2% malt extract agar (MEA; 20 g malt extract, 20 g agar, 1 L water). After inoculation, agar plates were incubated at 25 °C to induce germination of spores. Single germinating spores were then transferred to clean plates under a dissecting microscope with a sterile needle. Specimens and isolates were deposited in the Museum of Beijing Forestry University (
Species identification was based on the morphological characters of apothecia and conidiomata 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. Cultural characteristics of isolates incubated on MEA in the dark at 25 °C were recorded.
Genomic DNA was extracted from axenic living cultures on MEA with cellophane using a modified CTAB method (Doyle and Doyle 1990). The internal transcribed spacer (ITS) region was amplified with primers ITS1 and ITS4 (
Sequences from this study and reference sequences obtained from GenBank (Table
Strains and NCBI GenBank accession numbers used in this study. Strains from this study are in bold.
Species | Strain | Genbank | |
---|---|---|---|
ITS | LSU | ||
Davidhawksworthia ilicicola | CBS 734.94 | KU728517 | KU728556 |
Davidhawksworthia ilicicola | CBS 261.95 | KU728516 | KU728555 |
Dermea acerina | CBS 161.38 | AF141164 | DQ247801 |
Dermea ariae | CBS 134.46 | AF141158 | NA |
Dermea cerasi | CBS 136.46 | AF141159 | NA |
Dermea chinensis | CFCC 53008 | MK330013 | MK626645 |
Dermea chinensis | CFCC 53009 | MK330014 | MK626646 |
Dermea chinensis | CFCC 53010 | MK330015 | MK626647 |
Dermea hamamelidis | CBS 137.46 | AF141157 | NA |
Dermea padi | CBS 140.46 | AF141160 | NA |
Dermea persica | MFLU 16-0259 | MH104719 | MH104720 |
Dermea prunastri | CBS 143.46 | AF141162 | NA |
Dermea pruni | CFCC 53006 | MK330016 | MK626648 |
Dermea pruni | CFCC 53007 | MK330017 | MK626649 |
Dermea viburni | CBS 145.46 | AF141163 | NA |
Mollisia dextrinospora | ICMP 18083 | HM116746 | HM116757 |
Neofabraea inaequalis | CBS 326.75 | KR859081 | KR858872 |
Neofabraea kienholzii | CBS 126461 | KR859082 | KR858873 |
Neofabraea malicorticis | CBS 122030 | KR859086 | KR858877 |
Neofabraea perennans | CBS 102869 | KR859087 | KR858878 |
Pezicula aurantiaca | CBS 201.46 | KR859102 | KR858893 |
Pezicula cornina | CBS 285.39 | KR859163 | KR858915 |
Pezicula cinnamomea | CBS 239.96 | KR859124 | KR858955 |
Pezicula eucrita | CBS 259.97 | KR859179 | KR858971 |
Pezicula neosporulosa | CBS 101.96 | KR859223 | KR859015 |
Pezicula pseudocinnamomea | CBS 101000 | KR859235 | KR859027 |
Pezicula sporulosa | CBS 224.96 | KR859261 | KR859053 |
Phlyctema vincetoxici | CBS 123727 | KF251207 | KF251710 |
Phlyctema vincetoxici | CBS 123743 | KF251208 | KF251711 |
Pseudofabraea citricarpa | CBS 130533 | KR859281 | KR859075 |
Pseudofabraea citricarpa | CBS 130297 | KR859279 | KR859073 |
The alignment based on the combined sequence dataset (ITS and LSU) contained 1431 characters. Of these, 1136 characters were constant, 103 variable characters were parsimony-uninformative, and 192 parsimony informative. The MP analyses resulted in five equally most parsimonious trees, with the first tree (TL = 601, CI = 0.647, RI = 0.807, RC = 0.522), which is shown in Figure
Dermea chinensis differs from D. molliuscula by its wider ascospores
CHINA. SHAANXI PROVINCE, Ankang City, Huoditang forest park, 33°26'12"N, 108°26'42"E, 1650 m a.s.l., on branches of Betula albosinensis, N. Jiang & C.M. Tian leg., 18 Jul 2018 (holotype
Named after the country where it was first discovered, China.
Asexual morph of Dermea chinensis from Betula albosinensis (
Sexual Asexual morph: apothecia erumpent, scattered or sometimes gregarious, circular, sinuate, sessile to substipitate, 2.1–3.5 mm wide, 0.8–1.2 mm high (av. = 2.7 × 0.9 mm, n = 10), dark brown to black, hard, leathery to horny in consistency, hymenium at the first concave, becoming plane or convex, roughened, sometimes cracked, occasionally slightly umbilicate; tissue of the basal stroma pseudoparenchymatous, composed of closely interwoven hyphae with elongated cells about 8 μm in diameter, hyaline to brownish, thick walled, curving towards the outside, forming a darker, pseudoparenchymatous excipulum of thick-walled cells about 8 μm in diameter; subhymenium a narrow zone of closely interwoven hyphae about 3 μm in diameter. Asci 85–118 × 14–19 μm (av. x‒= 96.5 × 16.4 μm, n = 10), cylindric-clavate, tapering below into a short stalk, 8-spored. Paraphyses hyaline, filiform, septate, simple or branched, 1.5–2.5 in diameter, the tips slightly swollen up to 4 μm and glued together forming a yellowish epithecium. Ascospores (14.2–)16.3–17.1(–18.6) × (7.3–)7.5–8.5(–8.9) μm, l/w = (1.8–)1.9–2.2(–2.3) (n = 50), ellipsoid-fusiform, hyaline to yellowish-brown, straight or slightly curved, aseptate, irregular biseriate. Asexual morph: conidial fruiting bodies erumpent, gregarious, columnar to subconical, 0.5–2.5 mm wide, 0.4–0.7 mm high (av. = 1.6 × 0.6 mm, n = 10), yellowish, furfuraceous to glabrous, tearing open irregularly and widely at the top, waxy in consistency, more fresh when moist, usually containing 3–8 more or less lobed cavity. Conidiophores 7–18 × 2–3.5 μm, hyaline, aseptate, unbranched, tapering to a slender tip. Conidiogenous cells 5–15 × 1.5–3 μm, determinate, phialidic, cylindrical, hyaline. Conidia (54–)60–72(–78) × (3.2–)3.5–4(–4.2) μm, hyaline, fifiform, straight or curved, one-celled. Microconidia absent.
On MEA at 25 °C colonies grow slowly, reaching 50 mm diameter within 60 d, pale yellow at first, gradually turning dark brown with scanty aerial mycelium.
On dead corticated branches of Betula albosinensis.
CHINA. SHAANXI PROVINCE, Ankang City, Qinling Mountain, 33°26'12"N, 108°26'42"E, 1570 m a.s.l., on branches of Betula albosinensis, N. Jiang & C.M. Tian leg., 15 Jul 2018 (
Three isolates of D. chinensis were obtained from Betula albosinensis cluster in a well-supported clade (MP/ML = 100/100) and appeared closely related to D. cerasi from Prunus branches. Dermea chinensis and D. cerasi are similar in macroconidia dimensions (54–78 × 3.2–4.2 μm in D. chinensis vs 40–60 × 2.5–4.5 μm in D. cerasi) but different in ascospore dimensions (14.2–18.6 × 7.3–8.9 μm in D. chinensis vs 15–20 × 5–7.5 μm in D. cerasi) and host associations (
Sexual Asexual morph: see Groves (1952). Asexual morph: conidial fruiting bodies erumpent, gregarious, pulvinate, 0.6–2.3 mm wide, 0.2–0.35 mm high (av. = 1.8 × 0.28 mm, n = 10), yellowish, furfuraceous to glabrous, tearing open irregularly and widely at the top, waxy in consistency, more fresh when moist, usually containing up to 30 more or less lobed cavities. Conidiophores 4–15 × 1.5–2.5 μm, hyaline, aseptate, unbranched, tapering to a slender tip. Conidiogenous cells 3.5–15 × 1.5–2.5 μm, determinate, phialidic, cylindrical, hyaline. Conidia (62–)75–88(–95) × (2–)2.5–3.3(–3.5) μm, hyaline, fifiform, straight or curved, two-celled. Microconidia absent.
Asexual morph of Dermea pruni from Prunus cerasifera f. atropurpurea (
On MEA at 25 °C colonies grow slowly, reaching 50 mm diameter within 50 d, at first pale yellow, gradually becoming dark brown with scanty aerial mycelium.
On dying stems and branches of Prunus cerasifera f. atropurpurea.
CHINA. SHAANXI PROVINCE, Ankang City, Qinling Mountain, 33°26'7"N, 108°26'48"E, 1570 m asl, on branches of Prunus cerasifera f. atropurpurea, N. Jiang & C.M. Tian leg., 23 Jul 2018 (
Dermea pruni was proposed based on a specimen collected from Prunus branches in Sichuan province, China. However, no living culture or DNA data were available (
In this study, we collected several Dermea specimens from China and morphologically and molecularly examined them. Dermea chinensis from Betula trees is introduced, which can be distinguished from D. molliuscula by aseptate and wider ascospores, and from other species by host association (Table
Comparison of phenotypic characters of currently accepted Dermea species.
Species | Host genera | Ascospores dimension (µm); septation | Macroconidia dimension (µm); septation | Microconidia dimension (µm) | Reference |
---|---|---|---|---|---|
D. abietinum | Abies; Tsuga | 20–30 × 6–8; 1–4-celled | 60–75 × 4–5; 1–4-celled | 11–22 × 1.0–1.5 |
|
D. acerina | Acer | 13–20 × 5–8; 1–4-celled | 15–25 × 5–8; 1-celled | 6–10 × 1.0–2.0 |
|
D. ariae | Sorbus | 12–18 × 3–5; 1–4-celled | 15–20 × 2.0–4.0; 1–2-celled | NA |
|
D. bicolor | Amelanchier | 12–15 × 3–4; 1–2-celled | 15–20 × 2.5–4.0; 1–2-celled | NA |
|
D. boycei | Pseudotsuga | 16–28 × 4–7; 1–4-celled | 42–56 × 3–4; 1–4-celled | 8–14 × 1–2 | Funk 1967; Johnston 2014 |
D. cerasi | Prunus | 15–20 × 5–7.5; 1–4-celled | 40–60 × 2.5–4.5; 1–2-celled | 12–23 × 1.0–1.5 |
|
D. chinensis | Betula | 14–19 × 7–9; 1-celled | 54–78 × 3.2–4.2; 1-celled | NA | This study |
D. chionanthi | Chionanthus | 18–25 × 7–9; 1–2(–4)- celled | 25–35 × 5–7; 1–2-celled | NA |
|
D. grovesii | Picea | 16.5–21.5 × 6–5; 1–3- celled | 60–95 × 6.5–8; 7–11-celled | NA |
|
D. hamamelidis | Hamamelis | 15–20 × 5.0–7.5; 1–4- celled | 18–25 × 4.5–6.0;1–2-celled | NA |
|
D. libocedri | Libocedrus | 15–20 × 6–8; 1–4-celled | 42–65 × 4–6; 1–4-celled | 10–18 × 1.0–1.5 |
|
D. molliuscula | Betula | 15–20 × 4–7; 1–4-celled | 50–75 × 2.5–3.5; 1–4-celled | 7–12 × 1.0–1.5 |
|
D. padi | Prunus | 15–20 × 5–7; 1–4-celled | 20–28 × 2.5–4.0; 1–2-celled | 4–6 × 1.5 |
|
D. persica | NA | NA | 20–25 × 2.5–3.5; 1-celled | NA |
|
D. piceina | Picea | 12–14 × 6–8; 1–2(–4)- celled | 22–40 × 3–5; 1–4-celled | 9–15 × 1.0–1.5 |
|
D. pinicola | Pinus | 13–18 × 5.0–7.5; 1–2- celled | 30–40 × 4–6; 1–4-celled | NA |
|
D. prunastri | Prunus | 15–20 × 5.0–7.5; 1–4- celled | 20–30 × 5–7; 1-celled | 7–10 × 1.5 |
|
D. pruni | Prunus | 15–20 × 8–10; 1(–4)-celled | 62–95 × 2–3.5; 2-celled | NA |
|
D. rhytidiformans | Abies | 18–28 × 8–11; 1-celled | 25–65 × 3.5–5.5; 1–4-celled | 10–22 × 1.5 |
|
D. stellata | Nemopanthus | 12–18 × 4–6; 1–2(–4)- celled | 40–55 × 2.5–4.5; 1–2-celled | 8–13 × 1.5–2.0 |
|
D. tetrasperma | Pseudotsuga | 14–17 × 4–6; 1-celled | 15–22 × 5–6; 1-celled | NA |
|
D. tulasnei | Fraxinus | 15–20 × 6–8; 1–4-celled | 25–40 × 6–8; 1-celled | NA |
|
D. tumifaciens | Capparis | 13 × 5.4 / 10–19 × 4.8–9.6; 2-celled | 18 × 7 / 15–22 × 4–9; 2- celled | NA |
|
D. viburni | Viburnum | 14–18 × 3.5–5.5; 1–2- celled | 30–45 × 2.5–4.0; 1–4-celled | NA |
|
The genus Pezicula is a phylogenetically close to Dermea species and has recently been confirmed based on an ITS-28S-16S rDNA analysis (
Species of Dermea are well-circumscribed by morphological characteristics. However, only 10 species (Table
This study was financed by the National Natural Science Foundation of China (Project No.: 31670647). 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.