Comoclathris typhicola, a new species for the funga of Iran

The genus Comoclathris Clem., typified by Comoclathris lanata Clem., was introduced by Clements (1909). Comoclathris belongs to the family Pleosporaceae (Pleosporales, Dothideomycetes, Pezizomycotina, Ascomycota) based on morphology and multi-locus phylogenetic analyses of the internal transcribed spacer (ITS‒rDNA) region, parts of the large and small subunit ribosomal RNA (LSU/SSU), and RNA polymerase II second largest subunit (RPB2) loci (Ariyawansa et al. 2015a,b, Wijayawardene et al. 2017, Mattoo et al. 2023). The genus is characterized by ascomata with circular lid-like openings and applanate reddish-brown to dark reddish-brown, muriform ascospores, with single longitudinal septa (Ariyawansa et al. 2015a, b, Wijayawardene et al. 2017). Presently, 50 epithets are listed for Comoclathris in Index Fungorum (https://www.indexfungorum.org/).
In this study, leaf samples from Typha latifolia L. (Typhaceae, Poales) showing necrotic lesions were collected from Miyandoab city, West Azarbaijan province, Iran, in 2021. Leaf samples were surface disinfected using 1% sodium hypochlorite solution for three min, followed by rinsing in sterile distilled water and incubated in a moist chamber at 25 °C. The incubated leaves were inspected under the stereo microscope (SZ51, Olympus, Japan) and single-spore isolation was done following the method described in Ahmadpour et al. (2021). Germinated spores were transferred to potato dextrose agar (PDA: 39 g/l sterile distilled water, Merck, Darmstadt, Germany) plates and incubated at room temperature for 2–4 weeks. The isolates were grown on PDA, malt extract agar (MEA) and oatmeal agar (OA) media at 25 °C under the near ultraviolet light (NUV)/dark period of 12/12 h for 7–14 days to study the morphological characteristics (Mattoo et al. 2023). Measurements and microphotographs were prepared from slide mounts in lactophenol using an Olympus AX70 compound microscope with differential interference contrast (DIC) illumination. Adobe Photoshop 2020 v. 2.10.8 software (Adobe Inc., San Jose, California) was used for manual editing. All identified isolates were deposited in the fungal culture collections of the Iranian Research Institute of Plant Protection (IRAN) and Urmia University (FCCUU). For total DNA extraction, the mycelial mass of each isolate harvested from 10-day-old PDA Petri dishes was homogenized in a standard sodium dodecyl sulfate (SDS) detergent lysis buffer and DNA was isolated using chloroform extraction and isopropanol precipitation method (Ahmadpour et al. 2021). Amplification and sequencing of RPB2 were carried out with primer pairs RPB2-5F2/RPB2-7cr2 as described by Ahmadpour et al. 2021. Maximum likelihood (ML) analysis was conducted in the RAxML‒HPC BlackBox v. 8.2.8 (Stamatakis 2014) online server of the CIPRES Science gateway portal (https://www.phylo.org/) (Miller et al. 2012) for 1000 bootstrapping iterations, using the general time reversible model (GTR) with a discrete gamma distribution. Sequences of Neocamarosporium chenopodii (CBS 206.80) and N. obiones (CBS 432.77) served as the outgroup taxa (Mattoo et al. 2023). The resultant phylogenetic trees were visualized in FigTree v. 1.4.4 (Rambaut 2019), and edited in graphic design software, Adobe Illustrator^® CC 2020. The newly generated sequences were submitted to GenBank. The resulting phylogram (Fig. 1) from the RPB2 phylogenetic analyses revealed that our isolates clustered well with Comoclathris typhicola (CBS 132.69 strain) with high bootstrap support values (ML = 100). To the best of our knowledge, this is the first report of C. typhicola for the funga of Iran.
Comoclathris typhicola (Cooke) Ariyaw. & K.D. Hyde, Fungal Diversity 71: 105 (2015) Fig. 2
Basionym: Sphaeria typhicola Cooke [as 'typhaecola'], Grevillea 5(no. 35): 121 (1877).
Synonyms: Clathrospora typhicola (Cooke) Höhn., Annls mycol. 16(1/2): 88 (1918), Macrospora typhicola (Cooke) Shoemaker & C.E. Babc., Can. J. Bot. 70(8): 1644 (1992), Pleospora typhicola (Cooke) Sacc., Reliq. Libert 2: no. 152 (1881), Pyrenophora typhicola (Cooke) E. Müll., Sydowia 5(3-6): 256 (1951).
Pathogenic on the leave of Typha latifolia. Lesions up to 5–20 mm diam., spread on the upper surface, scattered, distinct, regular to irregular, pale brown to dark brown, leading to leaf death. Sexual morph: Undetermined. Asexual morph: Coelomycetous. Conidiomata 180–200 × 190–200 μm, pycnidial, semi-immersed to immersed, mostly solitary, rarely aggregated, scattered, globose to subglobose, pale brown to brown, thin-walled, glabrous, closed to one inconspicuous pore, with creamy to yellow conidial matrix. Pycnidial wall 10–25 μm thick, pseudoparenchymatous, 3–5 layered, composed of oblong to isodiametric cells, pale brown. Conidiogenous cells 4–6 × 4–7 μm, phialidic, hyaline, smooth, globose to ampulliform. Conidia 3–4 × 1–1.2 μm (x̅ = 3.5 × 1.1 μm, n = 50), ellipsoidal to oblong, occasionally ovoid, with rounded ends, hyaline, smooth and thin-walled, aseptate, with polar guttules.
Culture characteristics ‒ Colonies on PDA reaching 57–59 mm diam. after seven days at 25 °C, smooth margin, sparse aerial mycelia, grey at the center, white at the margin; reverse white to pale brown. Colonies on MEA reaching 49–50 mm diam. after seven days at 25 °C, floccose, surface white, smooth margin, sparse aerial mycelia; reverse white, pale brown at the center. Colonies on OA reaching 53–55 mm diam. after seven days at 25 °C, smooth margin, surface white to grey, sparse aerial mycelia, abundant production of pycnidia, conidial matrix visible; reverse buff, with grey near the center.
Specimen examined ‒ IRAN, West Azarbaijan province, Miyandoab city, isolated from infected leaves of Typha latifolia (Typhaceae, Poales), 10 Sept. 2021, A. Ahmadpour, IRAN 4235C (RPB2 = OR611972) and FCCUU 1903 (RPB2 = OR611973).