Research Article |
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Corresponding author: Chayanard Phukhamsakda ( chayanard.phu@mfu.ac.th ) Academic editor: Danushka Sandaruwan Tennakoon
© 2025 Raheleh Asghari, Chayanard Phukhamsakda, E. B. Gareth Jones, Ali Bahkali, Carlo Chris S. Apurillo, Omid Karimi, Pattana Kakumyan, Kevin D. Hyde.
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:
Asghari R, Phukhamsakda C, Jones EBG, Bahkali A, Apurillo CCS, Karimi O, Kakumyan P, Hyde KD (2025) Morphology and phylogeny reveal two new species and host records of hyphomycetous fungi on Areca species from marine habitats in Thailand. MycoKeys 118: 179-206. https://doi.org/10.3897/mycokeys.118.147229
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The marine ecosystem is the largest on Earth, supporting a wide variety of organisms. Fungi in this environment are diverse and play promising ecological roles. This study investigated fungi on submerged, decaying plant materials of Areca species trapped between rocks in seawater in Prachuap Khiri Khan Province, Thailand. Morphological and multi-gene phylogenetic analysis (LSU-ITS-tub2-SSU for Tetraploa, ITS-LSU-tub2-rpb2 for Rosellinia, LSU-ITS-tef1-α-rpb2 for Musicillium and LSU-ITS-act for Sarocladium) revealed two new species: Tetraploa maritima, characterized by the presence of a hilum and elongating appendages, and Rosellinia maritima, distinguished by a brown to black conidial-like structure composed of interwoven, irregular cells without distinct conidiophores produced in sterile conditions, unlike other Rosellinia asexual morphs. Additionally, two new host records (Musicillium theobromae and Sarocladium gamsii) are documented, with detailed descriptions of their in vivo and in vitro morphologies. Detailed morphological descriptions and illustrations are provided. This study contributes to the understanding of fungal diversity in marine environments.
2 new species, marine fungi, molecular phylogeny, palm fungi, rocky shore, saprobe
Fungi live in a variety of ecosystems, from terrestrial to aquatic habitats on various substrates such as plant materials (
Several studies have been conducted on saprobic, endophytic and pathogenic fungi on palms (Arecaceae), showing the high diversity of fungi on this host family worldwide (
Fungal association with Areca has been studied predominantly with the focus of pathogenic fungi on the economically important species A. catechu (betel nut palm) (
Decaying submerged woody specimens were collected from the rocky shore at Pranburi, Prachuap Khiri Khan Province (Thailand) in October 2022. The specimens were placed in moist plastic bags and incubated in sterile seawater moist chambers after transferring to the laboratory. The moist chambers were treated with sterilized natural seawater regularly. The samples were examined for fungal presence after returning to the laboratory and up to one month of incubation. The fungal macro-characters were examined using a stereomicroscope (Olympus SZX16, Japan) equipped with an Olympus SC180 digital camera (Olympus, Japan). The fungal microscopic features, such as conidiophores, conidiogenous cells and conidia, were examined by preparing microscopic slides using distilled water or lactoglycerol, followed by using a Nikon ECLIPSE Ni compound microscope (Nikon, Japan) equipped with a Nikon DS-Ri2 digital camera (Nikon, Japan). The Tarosoft (R) Image Framework program (Tarosoft, Thailand) was used to measure the fungal characters, and Adobe Photoshop CS6 Extended version 13.1.2 software (Adobe Systems Inc., The United States) was used to process the figures. The single spore isolation method was employed to obtain pure cultures (
Fresh, pure cultures were selected for DNA extraction. Mycelium was scraped using sterilized surgical blades. Genomic DNA was extracted following the manufacturer’s protocol of a Mega Genomic DNA Extraction Kit (Omega Bio-tek Inc., The United States). Polymerase chain reactions (PCR) were conducted to amplify the internal transcribed spacer region rDNA (ITS), the 28S large subunit rDNA (LSU), the 18S small subunit rDNA (SSU), the RNA polymerase II second largest subunit (rpb2) gene, the translation elongation factor 1-alpha (tef1-α) gene, and the partial β-tubulin II (tub2). Primers and the PCR condition were described as in Table
| Gene Regions | Primers | PCR conditions | References |
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| ITS | ITS5/ITS4 | 95 °C for 5 min, 35 cycles of 94 °C for 45 s, 53 °C for 45 s, and 72 °C for 2 min, 72 °C for 10 min |
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| LSU | LR0R/LR5 | 94 °C for 4 min, 35 cycles of 95 °C for 45 s, 56 °C for 45 s, and 72 °C for 1 min, 72 °C for 10 min |
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| SSU | NS1/NS4 | 94 °C for 4 min, 35 cycles of 94 °C for 30 s, 55 °C for 50 s, and 72 °C for 1.30 min, 72 °C for 10 min |
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| rpb2 | fRPB2-5f/fRPB2-7cR | 95 °C for 5 min, 40 cycles of 95 °C for 1 min, 54 °C, 90 s, and 72 °C for 90 s, 72 °C for 10 min |
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| tef1-α | EF1-983F/EF1-2218R | 95 °C for 5 min, 40 cycles of 95 °C for 1 min, 54 °C, 90 s, and 72 °C for 90 s, 72 °C for 10 min |
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| tub2 | T1/T22 | 94 °C for 4 min, 35 cycles of 94 °C for 30 s, 55 °C for 50 s, and 72 °C for 1.30 min, 72 °C for 10 min |
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The generated sequences were assembled using SeqMan software version 7.1.0. The assembled sequences were searched on the Nucleotide BLAST search (https://blast.ncbi.nlm.nih.gov) to identify the closest taxa. The reference sequences of closely related taxa were obtained from previous publications (
The combined analysis of LSU, ITS, tub2 and SSU sequence data of Tetraploa was performed with Muritestudina chiangraiensis (
Phylogram generated from maximum likelihood analysis based on combined LSU, ITS, tub2 and SSU sequence data of Tetraploa. Maximum likelihood bootstrap support ≥ 65% and Bayesian posterior probabilities (BPP) ≥ 0.90 are given near the nodes, respectively. The tree is rooted to Muritestudina chiangraiensis (
The combined analysis of ITS, LSU, tub2 and rpb2 sequence data of Xylariaceae was performed with Hypoxylon rickii (MUCL 53309) and H. fragiforme (MUCL 51264) as the outgroup taxa (Fig.
Phylogram generated from maximum likelihood analysis based on combined ITS, LSU, tub2 and rpb2 sequence data of Xylariaceae. Maximum likelihood bootstrap support ≥ 65% and Bayesian posterior probabilities (BPP) ≥ 0.90 are given near the nodes, respectively. The tree is rooted to Hypoxylon rickii (MUCL 53309) and H. fragiforme (MUCL 51264). The newly generated sequences are indicated in red, and the type strains are indicated in bold.
The combined analysis of LSU, ITS, tef1-α and rpb2 sequence data of Plectosphaerellaceae was performed with Cylindrotrichum clavatum (CBS 125296, CBS 125297) as the outgroup taxa (Fig.
Phylogram generated from maximum likelihood analysis based on combined LSU, ITS, tef1-α and rpb2 sequence data of Plectosphaerellaceae. Maximum likelihood bootstrap support ≥ 65% and Bayesian posterior probabilities (BPP) ≥ 0.90 are given near the nodes, respectively. The tree is rooted to Cylindrotrichum clavatum (CBS 125296, CBS 125297). The newly generated sequence is highlighted in yellow and the type strains are indicated in bold.
Phylogram generated from maximum likelihood analysis based on combined LSU, ITS and act sequence data of Sarocladium. Maximum likelihood bootstrap support ≥ 65% and Bayesian posterior probabilities (BPP) ≥ 0.90 are given near the nodes, respectively. The tree is rooted to Kiflimonium curvulum (CBS 430.66, CBS 384.70A). The newly generated sequence is highlighted in yellow, and the type strains are indicated in bold.
The combined analysis of LSU, ITS and act sequence data of Sarocladium was performed with Kiflimonium curvulum (CBS 430.66, CBS 384.70A) as the outgroup taxa (Fig.
The epithet “maritima” refers to the marine habitat where the holotype was collected.
Saprobic
on decaying branches of Areca sp. Sexual morph: Undetermined. Asexual morph: Hyphomycetous (in vivo, Fig.
Tetraploa maritima (
Conidia germinating on PDA within 12 h. Colonies on PDA reaching 1.5 cm diam. after 10 d at 25 ± 2 °C, velvety to floccose, raised, round, entire margin, grayish yellow, with whitish edge, reverse reddish brown with pale buff edge.
Thailand, Prachuap Khiri Khan Province, Pranburi, on decaying Areca wood submerged in seawater and trapped between rocks, 25 October 2022, K.D. Hyde, R6g (
The reconstruction of phylogenies from LSU, ITS, tub2 and SSU sequence data showed that Tetraploa maritima (
The epithet “maritima” refers to the marine habitat where the holotype was collected.
Saprobic
on decaying branches of Areca sp. Sexual morph: Undetermined. Asexual morph: Hyphomycetous (in vivo, Fig.
Rosellinia maritima (
Conidia germinating on PDA within 12 h. Colonies on PDA reaching 5 cm diam. after one month at 25 ± 2 °C, felty, flat, round, entire margin, dull, gray and white concentric rings, with dirty whitish edge, reverse dark brown with olivaceous gray edge.
Thailand, Prachuap Khiri Khan Province, Pranburi, on decaying Areca wood submerged in seawater and trapped between rocks, 25 October 2022, K.D. Hyde, R6c (
The construction of phylogenies from combined ITS, LSU, tub2 and rpb2 sequence data showed that Rosellinia maritima (
Saprobic
on decaying branches of Areca sp. Sexual morph: Undetermined. Asexual morph: Hyphomycetous (in vivo, Fig.
Musicillium theobromae (
Musicillium theobromae (
Conidia germinating on PDA within 12 h. Colonies on PDA reaching 2 cm diam. after two weeks and 4 cm diam. after two months at 25 ± 2 °C, finely floccose, round, entire margin to finely rhizoid, white and gray brown at the center, becoming raised and brown with age. Reverse white with gray brown at the center, becoming darker with age.
Thailand, Prachuap Khiri Khan Province, Pranburi, on decaying Areca wood submerged in seawater and trapped between rocks, 25 October 2022, K.D. Hyde, R6a (
The reconstruction of phylogenies from LSU-ITS-tef1-α-rpb2 sequences showed that Musicillium theobromae (
Saprobic
on decaying branches of Areca sp. Sexual morph: Undetermined. Asexual morph: Hyphomycetous (in vivo, Fig.
Sarocladium gamsii (
Conidia germinating on PDA within 12 h. Colonies on PDA reaching 2.5 cm diam. after one month and 3 cm diam. after two months at 25 ± 2 °C, umbonate, radially folded, lobate to irregular, yellowish white. Reverse buff.
Thailand, Prachuap Khiri Khan Province, Pranburi, on decaying Areca wood submerged in seawater and trapped between rocks, 25 October 2022, K.D. Hyde, R6d (
The reconstruction of phylogenies from combined LSU, ITS and act sequences showed that Sarocladium gamsii (
Marine fungi are a taxonomically diverse group, playing crucial ecological roles as saprobes, endophytes, symbionts, and pathogens (
Tetraploa (Tetraplosphaeriaceae, Pleosporales, Dothideomycetes) was introduced by
Rosellinia (Xylariaceae, Xylariales, Sordariomycetes) was described by
Musicillium (Plectosphaerellaceae, Glomerellales, Sordariomycetes) was introduced by
Sarocladium (Sarocladiaceae, Hypocreales, Sordariomycetes) is a hyphomycetous genus introduced by
The four genera examined in this study—Tetraploa, Rosellinia, Musicillium, and Sarocladium—along with the previously examined genus Myrmecridium (
Raheleh Asghari would like to thank the Mae Fah Luang University Partial Scholarship for the doctoral degree program (GR-ST-PS-65-21), Mushroom Research Foundation, and the National Research Council of Thailand (NRCT) grant “Total fungal diversity in a given forest area with implications towards species numbers, chemical diversity, and biotechnology” (grant no. N42A650547) for support. Permission for surveys, studies, research or academic experiments (No. 0907.4/23579) in the National Parks (book no. 02/020) and the Forest Parks, Botanic Gardens and Arboreta (book no. 02/001) is acknowledged. Kevin D. Hyde would like to thank the Flexible Talent Introduction Program (E16441) and the Chinese Research Fund, grant number E1644111K1, titled “Flexible introduction of the high-level expert program, Kunming Institute of Botany, Chinese Academy of Sciences” for support. Gareth Jones and Kevin D. Hyde are supported under the Distinguished Scientist Fellowship Program (DSFP), King Saud University, Kingdom of Saudi Arabia. Chayanard Phukhamsakda would like to thank the Basic Research Fund (Fundamental Fund) supported by the National Science, Research, and Innovation Fund under Grant No. 682A16032. Carlo Chris S. Apurillo would like to thank the Mae Fah Luang University for the partial scholarship grant (GR-ST-PS-65-21), Mushroom Research Foundation for financial support and the Department of Science and Technology-Philippine Science High School-EVC for the grant of study leave. Dr. Shaun Pennycook is thanked for advice regarding the new epithet. We would like to thank Dr. Martin van de Bult for the identification of the host.
The authors have declared that no competing interests exist.
No ethical statement was reported.
This work is grateful to the Basic Research Fund (Fundamental Fund) supported by the National Science, Research and Innovation Fund under Grant No. 682A16032 for full financial support.
Supervision and review: ChP, EBGJ, PK, KDH, AB. Writing – original draft: RA, OK. Molecular analyses: RA, OK, CCSA.
Raheleh Asghari https://orcid.org/0009-0006-4897-5327
Chayanard Phukhamsakda https://orcid.org/0000-0002-1033-937X
E. B. Gareth Jones https://orcid.org/0000-0002-7286-5471
Ali Bahkali https://orcid.org/0000-0003-3936-0436
Carlo Chris S. Apurillo https://orcid.org/0000-0003-4348-0887
Omid Karimi https://orcid.org/0000-0001-9652-2222
Pattana Kakumyan https://orcid.org/0000-0001-8281-1082
Kevin D Hyde https://orcid.org/0000-0002-2191-0762
All of the data that support the findings of this study are available in the main text.