Pseudoophiobolus mathieui (Westend.) Phookamsak., Wanas., S.K. Huang, Camporesi & K.D. Hyde (2017)

Wijesinghe, Subodini N., Wang, Yong, Zucconi, Laura, Dayarathne, Monika C., Boonmee, Saranyaphat, Camporesi, Erio, Wanasinghe, Dhanushka N. & Hyde, Kevin D., 2021, Additions to Italian Pleosporinae, including Italica heraclei sp. nov., Biodiversity Data Journal 9, pp. 59648-59648 : 59648

Pseudoophiobolus mathieui (Westend.) Phookamsak., Wanas., S.K. Huang, Camporesi & K.D. Hyde (2017)

Pseudoophiobolus mathieui Sphaeria mathieui

Sphaeria mathieui Basionym: Sphaeria mathieui Westend., Bull. Acad. R. Sci. Belg., Cl. Sci., sér. 2: no. 5 (1859)

Materials

Type status: Other material. Occurrence: recordedBy: Erio Camporesi; Taxon: kingdom: Fungi; phylum: Ascomycota; class: Dothideomycetes; order: Pleosporales; family: Phaeosphaeriaceae; genus: Pseudoophiobolus; specificEpithet: mathieui; taxonRank: species; Location: stateProvince: Province of Ravenna; county: Italy; municipality: near Brisighella; Identification: identifiedBy: S.N. Wijesinghe; Event: year: 2018; month: 9; day: 10; habitat: on a dead areail stem of Artemisia sp. (Asterales, Asteraceae); fieldNotes: Terrestrial; Record Level: institutionID: MFLU 18-1907; institutionCode: Mae Fah Luang University Herbarium (MFLU); ownerInstitutionCode: IT4031 Type status: Other material. Record Level: type: living culture; collectionID: MFLUCC 20-0150; collectionCode: Mae Fah Luang Culture Collection (MFLUCC)

Description

Saprobic on dead aerial stem of Artemisia sp. ( Asterales , Asteraceae ). Sexual morph: Ascomata (Fig. 4 a-b, c - with ostiole) 170-300 × 140-250 µm (x¯ = 200 × 177 µm, n = 10), solitary, scattered, dark brown to black, semi-immersed to erumpent, sessile, globose to subglobose, uni-loculate, coriaceous, ostiolate and papillate. Papilla (Fig. 4 d) 70-150 × 60-120 µm, mammiform to oblong, with a rounded to truncate apex, thick walled, composed of several layers, brown to dark brown cells of textura angularis, ostiole central, single and without periphyses. Peridium (Fig. 4 e) 15-35 µm (x¯ = 20 µm, n = 15), brown to black, thick-walled, pseudoparenchymatous cells, composed of 4-6 cell layers, outer layers composed of dark brown loosely packed cells of textura angularis, inner layers composed of light brown to hyaline flattened cells of textura prismatica. Hamathecium comprising numerous, 1.5-2.5 µm wide (x¯ = 2 µm, n = 15), filamentous, distinctly septate, cellular pseudoparaphyses (Fig. 4 f) with guttules, slightly constricted at the septa, anastomosing at the apex, embedded in a hyaline gelatinous matrix. Asci (Fig. 4 g-j) 100-150 × 6-9 µm (x¯ = 132 × 8 µm, n = 15), 8-spored, bitunicate, fissitunicate, cylindrical to cylindrical-clavate, short furcate pedicel, apically rounded, well-developed ocular chamber. Ascospores (Fig. 4 k-m) 120-150 × 2-3 µm (x¯ = 131 × 2.8 µm, n = 25), fasciculate, lying parallel or spiral at the centre, scolecosporous, filiform or filamentous, narrowly rounded towards the ends, slightly swollen at the middle of 4th or 5th cell from the apex (Fig. 4 n), yellowish to yellowish brown, 15-18 septate and not constricted at the septa, smooth-walled. Asexual morph: Undetermined.

Culture characteristics: Ascospores germinating on PDA within 4 days, from single-spore isolation. Colonies (Fig. 4 o-p) on PDA reaching 10-15 mm diam. after 14 days at 16°C, circular, entire edge, flat, dense, pale yellow in both upper and lower centres, white at the edges in both sides.

GenBank accession numbers (ex-MFLUCC 20-0150): SSU = MT880290, ITS = MT880294, LSU = MT880292, TEF = MT901292

Notes

Pseudoophiobolus was introduced by Phookamsak et al. (2017) to accommodate Ophiobolus -like taxa, including P. mathieui , characterised by ascospores that are subhyaline to pale yellowish or yellowish, with a swollen cell, lacking terminal appendages and not separating into part spores. Both the new Italian strain (MFLUCC 20-0150) and the previously-isolated ex-type strain of P. mathieui (MFLUCC 17-1785) were collected from the Province of Forlì-Cesena, on Artemisia sp. ( Asterales , Asteraceae ) and Salvia sp. ( Lamiales , Lamiaceae ), respectively. Further records were reported for the same Province on Origanum vulgare ( Lamiales , Lamiaceae ) and Ononis spinosa ( Fabales , Fabaceae ) ( Phookamsak et al. 2017). Characteristics of our material resemble the holotype ( Phookamsak et al. 2017). The holotype of P. mathieui (MFLUCC 17-1785) and our newly-isolated strain (MFLUCC 20-0150) were similar in ascomata, ostiole, peridium and asci, but the ascomatal ostiole of MFLUCC 20-0150 was composed of cells of textura angularis, whereas, in MFLUCC 17-1785, the cells were of textura angularis to textura prismatica (Fig. 4 ).

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 ).

Figures

Figure 4. 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.