Biodiversity Data Journal :
Taxonomic Paper
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Corresponding author: Yong Wang (yongwangbis@aliyun.com)
Academic editor: Danny Haelewaters
Received: 14 Oct 2020 | Accepted: 23 Dec 2020 | Published: 18 Jan 2021
© 2021 Subodini Wijesinghe, Yong Wang, Laura Zucconi, Monika Dayarathne, Saranyaphat Boonmee, Erio Camporesi, Dhanushka N. Wanasinghe, 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:
Wijesinghe SN, Wang Y, Zucconi L, Dayarathne MC, Boonmee S, Camporesi E, Wanasinghe DN, Hyde KD (2021) Additions to Italian Pleosporinae, including Italica heraclei sp. nov. Biodiversity Data Journal 9: e59648. https://doi.org/10.3897/BDJ.9.e59648
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In the last few years, many microfungi—including plant-associated species—have been reported from various habitats and substrates in Italy. In this study of pleosporalean fungi, we researched terrestrial habitats in the Provinces of Arezzo (Tuscany region), Forlì-Cesena and Ravenna (Emilia-Romagna region) in Italy.
Our research on Italian pleosporalean fungi resulted in the discovery of a new species, Italica heraclei (Phaeosphaeriaceae). In addition, we present a new host record for Pseudoophiobolus mathieui (Phaeosphaeriaceae) and the second Italian record of Phomatodes nebulosa (Didymellaceae). Species boundaries were defined, based on morphological study and multi-locus phylogenetic reconstructions using Maximum Likelihood and Bayesian Inference analyses. Our findings expand the knowledge on host and distribution ranges of pleosporalean fungi in Italy.
one new species, Ascomycota, Dothideomycetes, integrative taxonomy, morphology, phylogeny
A number of prominent scholars contributing to the foundation of fungal classification were of Italian origin. Among the most important mycologists of the 19th century are Giuseppe De Notaris and Pier Andrea Saccardo, who were the earliest mycologists to validate microscopic characteristics as important features in fungal taxonomy (
The order Pleosporales is amongst the most family-rich ones in Dothideomycetes (
Phaeosphaeriaceae was introduced by
Didymellaceae is another family in Pleosporales introduced by
Currently, a total of 83 and 35 genera are accounted for Phaeosphaeriaceae and Didymellaceae, respectively (
Sample collection, morphological studies and specimen deposition
Strains were isolated from dead stems of different host plants belonging to Apiaceae, Asteraceae and Urticaceae (dicotyledons) collected in the Provinces of Arezzo, Forlì-Cesena and Ravenna (Italy) from September to December 2018. Samples were preserved in sterile Ziploc bags in the laboratory at 18°C. Macromorphological characters of the samples were observed using a Motic SMZ 168 compound stereomicroscope and micromorphology was examined from hand-sectioned structures using a Nikon ECLIPSE 80i compound stereomicroscope, equipped with a Canon 600D digital camera. The measurements of photomicrographs were obtained using Tarosoft (R) Image Frame Work version 0.9.7. Images were edited with Adobe Photoshop CS6 Extended version 13.0.1 software (Adobe Systems, San Jose, California).
Single-spore isolation was carried out as described by
The administrative boundaries of Italy and geocodes for collecting sites related to our newly-isolated species were mapped by using QGIS version 3.14 (QGIS Geographic Information System, Open Source Geospatial Foundation Project. http://qgis.org/). Geocodes of collecting locations were confirmed with GoogleEarthPro version 7.3.3 (the data providers were: Image Landsat/Copernicus, Data SIO, NOAA, US. Navy, NGA, GEBCO, US Dept. of State Geographer, https://www.google.com/earth/). The data files (.cvs and .shp) for administrative boundaries were downloaded from DIVA-GIS for mapping and geographic data analysis (
The methodology for DNA extraction, PCR, gel electrophoresis and sequencing was followed, as detailed in
Gene regions, primers and PCR thermal cycle programmes used in this study, with corresponding reference(s).
Genes/loci |
PCR primers (forward/reverse) |
PCR conditions |
Reference(s) |
ITS and LSU |
ITS5/ITS4 and LR0R/LR5 |
94°C; 2 min (95°C; 30 s, 55°C; 50 s, 72°C; 90 s) × 35 thermal cycles, 72°C; 10 min. |
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SSU |
NS1/NS4 |
95°C; 3 min (95°C; 30 s, 55°C; 50 s, 72°C; 30 s) × 35 thermal cycles, 72°C; 10 min. |
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TEF |
EF1-983F/EF1-2218R |
94°C; 2 min (95°C; 30 s, 58°C; 50 s, 72°C; 1 min), × 35 thermal cycles, 72°C; 10 min. |
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TUB2 |
Bt2a/Bt2b |
94°C; 2 min (94°C; 1 min, 58°C; 1 min, 72°C; 90 s), × 35 thermal cycles, 72°C; 10 min. |
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Contig sequences were checked with BLAST searches in NCBI for primary identifications. Sequences for phylogenetic analyses were downloaded from GenBank following
Phylogenetic analyses were run on the CIPRES Science Gateway portal (
For the phylogenetic analysis of Phaeosphaeriaceae, Tintelnotia destructants (CBS 127737) and T. opuntiae (CBS 376.91) were selected as outgroup taxa. The dataset comprised 52 taxa, including our new isolates. The final concatenated dataset comprised 3307 characters including gaps. ML and BI analyses resulted in similar tree topologies. The final RAxML tree is shown in Fig.
Phylogeny of the family Phaeosphaeriaceae, reconstructed from the combined SSU–ITS–LSU–TEF dataset. Tintelnotia destructants (CBS 127737) and T. opuntiae (CBS 376.91) serve as outgroup taxa. ML ≥ 70 and PP ≥ 0.95 are presented above each node. The new isolates are indicated in bold; T = type strains. The scale bar represents the expected number of nucleotide substitutions per site.
In our phylogenetic analyses, the new species Italica heraclei (MFLUCC 20-0227) formed a phylogenetically-distinct lineage with high support (82 ML/0.98 PP) (Clade B, Fig.
For Didymellaceae, Leptosphaeria conoidea (CBS 616.75) and L. doliolum (CBS 505.75) were selected as outgroup taxa. The concatenated ITS–LSU–RPB2–TUB2 dataset comprised 55 taxa, including our new isolates. The final dataset comprised 2154 characters including gaps. ML and BI analyses resulted in similar tree topologies. The final RAxML tree is shown in Fig.
Phylogeny of the family Didymellaceae, reconstructed from the combined ITS–LSU–RPB2–TUB2 dataset. Leptosphaeria conoidea (CBS 616.75) and L. doliolum (CBS 505.75) serve as outgroup taxa. ML ≥ 70 and PP ≥ 0.95 are presented above each node. The new isolate is indicated in bold; T = type strains. The scale bar represents the expected number of nucleotide substitutions per site.
In our phylogenetic analyses, the newly-isolated Italian strain MFLUCC 20-0155 was grouped in Phomatodes (Clade A, Fig.
Saprobic on dead aboveground stem of Heracleum sphondylium L. (Apiales, Apiaceae). Sexual morph: Ascomata (Fig.
Italica heraclei (MFLU 18-1906). a-b. Ascomata on a dead stem of Heracleum sphondylium (Apiales, Apiaceae). c. Section of an ascoma. d. Peridium. e. Pseudoparaphyses. f-j. Asci. k-n. Ascospores. o-p. Colonies on PDA from upper (o) and lower (p) sides. Scale bars: a-b = 200 μm, c = 100 μm, d-j = 20 μm, k-n = 10 μm.
Culture characteristics: Ascospores germinating on MEA (malt extract agar) within 2 days, from single-spore isolation. Colonies (Fig.
GenBank accession numbers (ex-MFLU 18-1906T): SSU = MT881671, ITS = MT881676, LSU = MT881653, TEF = MT901290
Etymology: heraclei, referring to the host genus Heracleum from which the strains were isolated.
Notes: Italica heraclei (holotype MFLU 18-1906) was isolated from a dead aerial stem of Heracleum sphondylium (Apiales, Apiaceae), whereas I. achilleae (MFLUCC 14-0955) and I. luzulae (MFLUCC 14-0932) were previously isolated from Achillea millefolium (Asterales, Asteraceae) and Luzula sp. (Poales, Juncaceae), respectively. The strains of Italica heraclei (MFLUCC 20-0227) and I. achilleae (MFLUCC 14-0955) were collected from the same Province, Forlì-Cesena; Italica luzulae (MFLUCC 14-0932) was collected from Trento Province (
Italica heraclei (MFLUCC 20-0227) shows morphological characters that are typical for the genus, including coriaceous ascomata; filamentous, branched and septate pseudoparaphyses; and hyaline to yellowish-brown ascospores. Italica heraclei differs from other Italica species by its cylindrical asci and vertically aseptate (Fig.
From the comparison of the SSU, ITS, LSU and TEF sequences of I. heraclei (MFLUCC 20-0227) and I. luzulae (MFLUCC 14-0932, type species) strains, we detected 3/949 (0.31%), 67/517 (12.95%), 20/796 (2.51%) and 32/619 (5.16%) differences, respectively. From the comparison of SSU, ITS, LSU and TEF nucleotides of I. heraclei and I. achilleae (MFLUCC 14-0955), we found 1/950 (0.1%), 64/517 (12.37%), 7/796 (1.13%) and 28/619 (4.52%) differences, respectively. According to the results of our integrative taxonomy approach, we described I. heraclei (MFLUCC 20-0227) as a new species.
Basionym: Sphaeria mathieui Westend., Bull. Acad. R. Sci. Belg., Cl. Sci., sér. 2: no. 5 (1859)
Saprobic on dead aerial stem of Artemisia sp. (Asterales, Asteraceae). Sexual morph: Ascomata (Fig.
Pseudoophiobolus mathieui (MFLU 18-1907). a-b. Ascomata on dead host surface of Artemisia sp. (Asterales, Asteraceae). c. Section of an ascoma. d. Close-up of ostiole. e. Peridium. f. Pseudoparaphyses. g-j. Asci. k-m. Ascospores. n. Ascospore with a swollen point (arrow). o-p. Colonies on PDA from upper (o) to lower (p) sides. Scale bars: b, d = 100 μm, c, f = 50 μm, e, g, h, l, m = 20 μm, i, j = 10 μm, n = 5 μm.
Culture characteristics: Ascospores germinating on PDA within 4 days, from single-spore isolation. Colonies (Fig.
GenBank accession numbers (ex-MFLUCC 20-0150): SSU = MT880290, ITS = MT880294, LSU = MT880292, TEF = MT901292
Pseudoophiobolus was introduced by
From a comparison of ITS and LSU sequences between P. mathieui (type) and MFLUCC 20-0150 strain, both were identical. However, seven nucleotide differences (1.13%) were found between the TEF sequences of two strains. Following the integrative taxonomic approach with both morphological data and molecular phylogenetic analyses, we conclude that our new collection is Pseudoophiobolus mathieui and represents a new host record on Artemisia sp. (Asterales, Asteraceae).
≡ Sphaeria nebulosa Pers., Observ. mycol. (Lipsiae) 2: 69 (1800) [1799]
Saprobic on dead aboveground stem of Urtica dioica L. (Rosales, Urticaceae). Asexual morph: Coelomycetous. Conidiomata (Fig.
Phomatodes nebulosa (MFLU 18-2685). a-b. Conidiomata on a dead stem of Urtica dioica Rosales, Urticaceae). c. Longitudinal section of a conidioma. d. Conidiomatal wall. e-f. Development stages of conidiogenesis. g-j. Conidiospores. k. Germinating conidium. l-m. Colonies on PDA (l upper, m lower). Scale bars: a = 100 μm, c = 50 μm, b, k = 20 μm, d-e = 10 μm, f-j = 5 μm.
Culture characteristics: Conidia germinating on PDA within 24 h, from single-spore isolation. Colonies (Fig.
GenBank accession numbers (ex-MFLUCC 20-0155): ITS = MT880293, LSU = MT880295, TUB2 = MT901291
Phomatodes was introduced by
From the comparison of ITS, LSU and TUB2 sequences between P. nebulosa (CBS 100191-type) and P. nebulosa (MFLUCC 20-0155), both strains were identical. In our multi-locus phylogenetic analyses, the new isolate (MFLUCC 20-0155) and the ex-type strains of P. nebulosa (CBS 117.93, CBS 740.96, CBS 100191, MFLU 18-0177) clustered together with high support (99 ML/1.00 PP) (Fig.
Early records of Phomatodes nebulosa were reported on Armoracia rusticana (Brassicales, Brassicaceae) and Mercurialis perennis (Malpighiales, Euphorbiaceae) from the Netherlands, Thlaspi arvense (Brassicales, Brassicaceae) from Poland (
The pleosporalean fungal collections in this study originated from terrestrial habitats in the Provinces of Arezzo (Tuscany region), Forlì-Cesena and Ravenna (Emilia-Romagna region) in Italy (Fig.
At times, members of these fungal families are able to have pathogenic relationships with different host plants in different environments (
Y. Wang would like to thank National Natural Science Foundation of China (No. 31972222, 31560489), Program of Introducing Talents of Discipline to Universities of China (111 Program, D20023), Talent Project of Guizhou Science and Technology Cooperation Platform ([2017]5788-5, [2019]5641 and [2020]5001), Guizhou Science, Technology Department International Cooperation Basic project ([2018]5806). S.N. Wijesinghe would like to thank Mae Fah Luang University for financial support and S.C. Karunarathne, R.G.U. Jayalal and A.R. Rathnayaka for their precious assistance during this study. Further, S.N. Wijesinghe would like to acknowledge Robert Hijmans and team for offering free access data files in GIS mapping. D.N. Wanasinghe would like to thank the CAS President’s International Fellowship Initiative (PIFI) for funding his postdoctoral research (number 2019PC0008), the National Science Foundation of China and the Chinese Academy of Sciences for financial support under the following grants: 41761144055, 41771063 and Y4ZK111B01. K.D. Hyde would like to thank the Thailand Research Fund (“Impact of climate change on fungal diversity and biogeography in the Greater Mekong Sub-region RDG6130001”).