Paragaeumannomyces panamensis (Huhndorf & F.A. Fernández) Réblová & A.N. Mill., in Réblová, Nekvindová, Fournier & Miller, MycoKeys 74: 32 (2020)
Basionym – Chaetosphaeria panamensis Huhndorf & F.A. Fernández
Index Fungorum number: IF 836535; MycoBank number: MB 836535; Facesoffungi number: FoF 02657; Fig. 1
Saprobic on decaying, submerged wood in freshwater stream. Sexual morph: Ascomata 180–260×285–265 µm (x=235×210 μm, n=10), scattered, solitary, superficial, globose to subglobose, ostiolate, slightly papillate, coriaceous, not collapsing when dry, black, setose, rough-walled. Setae scattered, cover entire ascomata, dark, stiff, pointed, 40–85 µm long (x=62 μm, n=30). Peridium 35–65 µm (x=44 µm, n=20), thick, one-layered, composed of large isodiametric to polygonal, brown to dark brown cells. Asci 85–137 × 9–15 µm (x = 104 × 11 µm, n = 20), 8-spored, unitunicate, cylindrical, rounded at the apex. Ascospores 50–70×2–4 µm (x=62×3 µm, n=20), filiform, loosely fasciculate, straight or slightly curved, 7-septate, early stage without constrictions at the septa but late stage has constrictions at the septa, rounded at both ends, apical end broader than the basal end, hyaline, smooth-walled. Asexual morph: Undetermined.
Culture Characteristics – Ascospores germinated on PDA within 12 h at 25 °C, germ tubes produced from both ends. Colonies on PDA reaching 27 mm diam. in 10 days at 28 °C, flat, circular, irregular margin, greyish green from above with white aerial mycelia, reverse dark grey with white margin.
Material examined – China, Guangdong Province, Guangzhou City, Baiyun Mountain, on sub-merged decaying wood in a freshwater stream, 16 August 2021, Jizhen Fu, BYS05 (MHZU 22-0084, new geographical record), living culture ZHKUCC 22-0150.
Hosts and distribution – On decorticated wood in Panama (Matsushima 2003) and on decorticated twigs of Pinus in Thailand (Perera et al. 2016).
GenBank numbers – ITS: OR164934, LSU: OR164962.
Notes – In the combined ITS, LSU and tef1-α gene analyses (Fig. 2) shows that our collection (ZKUH 22-0084) clustered with Paragaeumannomyces panamensis and morphology of our collection is identical to the holotype of P. panamensis (Matsushima 2003; Perera et al. 2016). Therefore, taxonomic affiliation of our collection with P. panamensis was confirmed based on morphology and phylogeny. However, P. panamensis only reported from Panama and Thailand and this is the first report of P. panamensis in China.
Figure 1 – Paragaeumannomyces panamensis (ZKUH 22-0084). a–c Ascoma on substrate. d Vertical cross section of ascoma. e Peridium. f Setae. g Paraphyses. h–j Asci. k–n Ascospores. o Upper view of colony on PDA. p Reverse view of colony on PDA. Scale bars: d–n=20 µm
Figure 2 – The best scoring RAxML tree with a final likelihood value of − 4292.869723 of combined ITS (415 bp) and LSU (1098 bp) sequence data. The topology and clade stability of the combined gene analyses was compared to the single gene analyses. The tree is rooted with Chaetosphaeria fusiformis (CBS 101429). The matrix had 693 distinct alignment patterns with 33.02% undetermined characters and gaps. Estimated base frequencies were as follows; A=0.929735, C=0.028634, G=0.026025, T=0.015606; substitution rates AC=0.741911, AG=0.356590, AT=0.631883, CG=0.458695, CT=0.504294, GT=1.0; gamma distribution shape parameter α=0.563546. Ex-type strains are in bold and newly generated sequences are in blue bold. Bootstrap support for ML equal to or greater than 50% and BI equal to or greater than 0.90 are given above the nodes