Research Article |
Corresponding author: Ratchadawan Cheewangkoon ( ratchadawan.c@cmu.ac.th ) Academic editor: Andrew Miller
© 2018 Chanokned Senwanana, Kevin D. Hyde, Rungtiwa Phookamsak, E.B. Gareth Jones, Ratchadawan Cheewangkoon.
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:
Senwanna C, Hyde KD, Phookamsak R, Jones EBG, 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
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During studies of microfungi on para rubber in Thailand, we collected a new Coryneum species on twigs which we introduce herein as C. heveanum with support from phylogenetic analyses of LSU, ITS and TEF1 sequence data and morphological characters. Coryneum heveanum is distinct from other known taxa by its conidial measurements, number of pseudosepta and lack of a hyaline tip to the apical cell.
1 new species, Ascomycota , Hevea brasiliensis , Phylogeny, Taxonomy
The para rubber tree (Hevea brasiliensis) is a tropical plant belonging to family Euphorbiaceae (
Many Coryneum species have been reported as phytopathogens causing tree canker (
Fresh materials were collected from Chiang Rai, Thailand in 2016. Specimens were taken to the laboratory in zip lock bags and observed with a Motic SMZ 168 series stereomicroscope and photographed with an Axio camera on a Zeiss Discover V8 stereomicroscope. Sections of the conidiomata were mounted in double-distilled water (ddH2O) for morphological structures and photography. Images were taken using a Canon 600D camera on a Nikon ECLIPSE 80i microscope. All measurements were calculated using Tarosoft® Image Framework programme v.0.9.0.7. Photoplates were made using Adobe Photoshop CS6 version 13.0 (Adobe Systems U.S.A.). The specimens were deposited in the Mae Fah Luang University Herbarium, Chiang Rai, Thailand (
Genomic DNA was extracted from mycelium using Biospin Fungus Genomic DNA Extraction Kit (BioFlux®, Hangzhou, P.R. China) following the manufacturer’s protocol. The DNA product was kept at 4 °C for the DNA amplification and maintained at -20 °C for long term storage. The DNA amplification was carried out by polymerase chain reaction (PCR) using three genes, the 28S large subunit (LSU), internal transcribed spacer (ITS) and translation elongation factor 1 alpha gene (TEF1). The LSU gene was amplified by using the primers LROR and LR5 (
Phylogenetic analyses were conducted based on a combined gene of LSU, ITS and TEF1 sequence data. Sequence data of Coryneaceae from previous studies and representative strains of major classes in Diaporthales were downloaded from GenBank to supplement the dataset (Table
Isolates utilized in the phylogenetic tree and their GenBank and culture accession numbers.
Taxa | Culture AC no. | GenBank Accession number | ||
---|---|---|---|---|
ITS | LSU | TEF1 | ||
Asterosporium asterospermum | KT2125 | _ | AB553743 | _ |
Asterosporium asterospermum | KT2138 | _ | AB553744 | _ |
Chaetoconis polygoni |
|
_ | EU754141 | _ |
Coryneum castaneicola | 43-1 | _ | MH683551 | _ |
Coryneum castaneicola | 43-2 | MH683560 | MH683552 | _ |
Coryneum depressum | AR 3897 | _ | EU683074 | _ |
Coryneum heveanum |
|
MH778707 | MH778703 | MH780881 |
Coryneum heveanum |
|
MH778708 | MH778704 | _ |
Coryneum modonia | AR 3558 | _ | EU683073 | _ |
Coryneum perniciosum |
|
MH854812 | MH866313 | _ |
Coryneum umbonata |
|
MH859114 | MH870828 | _ |
Coryneum umbonatum | AR 3541* | _ | EU683072 | _ |
Coryneum umbonatum |
|
MF190120 | MF190066 | MF377574 |
Coryneum umbonatum |
|
MF190121 | MF190067 | MF377575 |
Crinitospora pulchra |
|
KJ710466 | KJ710443 | _ |
Cytospora centravillosa |
|
MF190122 | MF190068 | _ |
Cytospora centravillosa |
|
MF190123 | MF190069 | _ |
Cytospora melanodiscus | Jimslanding2 | JX438621 | _ | JX438605 |
Cytospora translucens | CZ320 | FJ755269 | FJ755269 | _ |
Diaporthe azadirachtae | TN 01 | KC631323 | _ | _ |
Diaporthe eres | AR 5193* | KJ210529 | _ | KJ210550 |
Diaporthe eres |
|
MF190138 | MF190081 | MF377595 |
Diaporthe maytenicola |
|
KF777157 | KF777210 | _ |
Hyaliappendispora galii |
|
MF190150 | MF190095 | MF377587 |
Lamproconium desmazieri |
|
KX430134 | KX430135 | MF377591 |
Lamproconium desmazieri |
|
KX430138 | KX430139 | MF377593 |
Macrohilum eucalypti | CPC 10945* | DQ195781 | DQ195793 | _ |
Macrohilum eucalypti | CPC 19421* | KR873244 | KR873275 | _ |
Pachytrype princeps | Rogers s.n.* | _ | FJ532382 | _ |
Pachytrype rimosa | FF1066 | _ | FJ532381 | _ |
Phaeoacremonium aleophilum |
|
AF266647 | AB278175 | KF764643 |
Phaeoacremonium vibratile |
|
KF764573 | DQ649065 | KF764645 |
Phaeoappendispora thailandensis |
|
MF190157 | MF190102 | _ |
Phaeoappendispora thailandensis |
|
MF190158 | MF190103 | _ |
Phaeodiaporthe appendiculata |
|
KF570156 | KF570156 | _ |
Prosopidicola mexicana |
|
AY720709 | KX228354 | _ |
Prosopidicola mexicana |
|
AY720710 | _ | _ |
Rossmania ukurunduensis | AR 3484* | _ | EU683075 | _ |
Stegonsporium acerophilum |
|
EU039982 | EU039993 | EU040027 |
Stegonsporium pyriforme |
|
EU039971 | EU039987 | EU040001 |
Stilbospora ellipsosporum | WJ 1840 | _ | AY616229 | _ |
Stilbospora macrosperma |
|
JX517290 | JX517299 | _ |
Sydowiella depressula |
|
_ | EU683077 | _ |
Sydowiella fenestrans |
|
JF681956 | EU683078 | _ |
Valsella salicis | AR 3514 | _ | EU255210 | EU222018 |
The estimated evolutionary model of Bayesian inference and maximum likelihood were performed independently for each locus using MrModeltest v. 2.3 (
Maximum likelihood analysis was performed by Randomized Accelerated Maximum Likelihood (RAxML) (Stamatakis 2008) version 7.4.2 (released by Alexandros Stamatakis on November 2012) implemented in raxmlGUI v.1.0 (
Maximum parsimony analysis was performed using PAUP v 4.0b10 (
Bayesian inference was performed in MrBayes v. 3.2.2 (
The phylogenetic tree was shown in FigTree V.1.4.3 (
The dataset consisted of 45 taxa including the new taxa (Figure
Maximum likelihood (RAxML) based on analysis of a combined dataset of LSU, ITS and TEF1 sequence data representing Diaporthales. Bootstrap support values for maximum likelihood (ML, left), maximum parsimony (MP, middle) greater than 70% and Bayesian posterior probabilities (BY, right) equal to or greater than 0.95 are indicated at the nodes. The tree is rooted to Phaeoacremonium aleophilum (
Named after the host on which it occurs, Hevea brasiliensis.
THAILAND, Chiang Rai Province, Wiang Chiang Rung District, on twigs (attached on tree) of Hevea brasiliensis, 1 November 2016, C. Senwanna, RBCR003 (
Associated with canker on twigs of Hevea brasiliensis. Asexual morph: Conidiomata acervular, solitary, erumpent through the outer periderm layers of host, scattered, surface tissues above slightly dome-shaped, black, velvety, formed of brown cell, thick-walled textura angularis, 145–540 µm diam. Conidiophores short, cylindrical, apically pale brown, paler at the base, smooth, septate, branched at the base, arising from basal stroma, 22–37 × 4–8 μm (x‒ = 28.5 × 5.6 μm, n = 15). Conidiogenous cell annellidic, integrated, terminal, cylindrical, medium brown, truncate apex, with 1-3 slightly percurrent proliferations, 6–17 µm long (x‒ = 10.7 μm, n = 20). Conidia curved, clavate to fusiform, dark brown, smooth-walled, 4–6-pseudo-septa, sometimes with apical and basal cells darker than other cells, rounded or sometime truncate at apex, truncate and black at the base, (40–)43–53(–68) × (14–)15–20 μm (x‒ = 48.7 × 17.3 μm, n = 85). Appressoria hyaline, globose to sub globose, thick-walled, 4–11 μm wide (x‒ = 7.1 μm, n = 20).
Conidia germinated on MEA within 24 h with germ tubes produced from one or both end cells, mostly from basal cell of conidia. Colonies on MEA reaching 20–25 mm diam. after 4 weeks at 25–30 °C, colonies circular, medium dense, cottony, margin wavy, superficial, slightly effuse, radially striated; colony from above, white, edges with more aerial mycelium than centre in the beginning and later become white grey, smooth with edge entire; from below: white to cream at the margin, yellowish-green in the centre in the beginning and later become dark green; not producing pigmentation in agar. Colonies on PDA reaching 10–15 mm diam. after 4 weeks at 25–30 °C, colonies circular, medium dense, cottony, slightly effuse, dark green with brown aerial mycelium on surface; not producing pigmentation in agar. Conidial masses were observed in PDA culture after 6 months at 25–30 °C. Mass of conidia dark brown to black, extruding on colony or tip of mycelium (Figure
Coryneum heveanum (
Phylogenetically, Coryneum heveanum clustered in the same clade with C. umbonatum, C. depressum, C. modonium, C. perniciosum and C. castaneicola with high statistical support. Based on morphological characters, the conidia of C. castaneicola, C. depressum, C. elevatum, C. modonium and C. umbonatum have slightly curved conidia with an apical cell with a hyaline tip, while C. heveanum, C. castaneicola and C. perniciosum lack a hyaline tip (Table
Fungi on para rubber (Hevea brasiliensis) can be pathogens, saprobes or endophytes (
Synopsis of recorded Coryneum species (asexual morph) (Related to this research).
Taxa | Size (µm) | Host records | ||
Conidiomata | Conidiophores | Conidia; Number of pseudo-septate | ||
Coryneum betulinum ( |
– | – | 31–36 × 14–17; 4–5 | Betula rubrum (Betulaceae) |
C. castaneicola ( |
– | – | 57–80 × 10–13; apical cell with a hyaline tip; 6–7 | Castanea dentata (Fagaceae) |
C. depressum ( |
– | – | 44–53 × 19–23; apical cell with a hyaline tip; 4–5(–6) | Quercus spp. (Fagaceae) |
C. elevatum ( |
56–70 × 24–32; apical cell with a hyaline tip; 6–7 | Quercus spp. (Fagaceae) | ||
C. heveanum This study | 145–540 | 22–37 × 4–8 | (40–)43–53(–68) × (14–)15–20; 4–6 | Hevea brasiliensis (Euphorbiaceae) |
C. modonium ( |
– | – | 50–71 × 14–19; apical cell with a hyaline tip; 5–8 | Castanea spp. (Fagaceae) |
C. perniciosum ( |
– | – | 40–50 × 13–15; 5–7 | Castanea sp. (Fagaceae) |
C. psidi ( |
– | – | 25–40 × 14–17; 5–6 | Psidium guajava (Myrtaceae) |
C. pyricola ( |
– | – | 61–70 × 24–32; 5–7 | Pyrus sp. (Rosaceae) |
C. umbonatum (Pseudovalsa longipes) (Wehmeyer 1926) | – | – | 47–104 × 10–14; 3–8 | Quercus coccinea (Fagaceae) |
C. umbonatum ( |
1500–2200 | (10–) 27.5–47 | 57–72 × 14–16; apical cell with a hyaline tip; 5–7 | Quercus spp. (Fagaceae), Castanea sativa (Fagaceae) |
C. umbonatum ( |
1000–1300 × 500–550 | 20–35 × 4–7 | 42–56 × 13–16; apical cell with a hyaline tip; 4–6 | Quercus sp. (Fagaceae) |
C. umbonatum ( |
450 × 700 | 20–30 × 3–6 | 35–45 × 8–10; apical cell with a hyaline tip; 4–6 | Quercus petraea (Fagaceae) |
Coryneum species are phytopathogenic fungi associated with twig blight, canker and dieback disease with some species reported as saprobes (Carter 1914,
Based on morphological characters, there are some similarities between Coryneum heveanum and related Coryneum species, such as acervular conidiomata, fusiform or clavate conidia with pseudosepta (
Current phylogenetic analyses of combined LSU, ITS and TEF1 alignment are used to clarify the species relationships in Coryneum (Figure
We would like to thank the Thailand Research Fund (TRF) grant no. MRG5580163, DGB6080013 and Chiang Mai University for financial support. C. Senwanna would like to thank the Key Research Program of Frontier Sciences, CAS (grant no. QYZDY-SSW-SMC014 and 973 key project of the National Natural Science Foundation of China (grant no. 2014CB954101) for supporting DNA molecular experiments of this study. R. Phookamsak expresses appreciation to the Research Fund from China Postdoctoral Science Foundation (grant no. Y71B283261), the Yunnan Provincial Department of Human Resources and Social Security (grant no. Y836181261), the National Nature Science Foundation of China (NSFC; grant no. 31850410489) and Chiang Mai University for financial support. We thank Milan C. Samarakoon and Sirinapa Konta for their valuable suggestions and helping in phylogenetic analyses. Dr. Shaun Pennycook is thanked for his essential nomenclatural review.