Pseudogymnoascus campensis Zhi. Y. Zhang & Y. F. Han, 2023

Zhang, Zhi-Yuan, Han, Yan-Feng, Chen, Wan-Hao & Tao, Gang, 2023, Additions to Thelebolales (Leotiomycetes, Ascomycota): Pseudogeomyces lindneri gen. et sp. nov. and Pseudogymnoascus campensis sp. nov., MycoKeys 95, pp. 47-60 : 47

Pseudogymnoascus campensis Zhi. Y. Zhang & Y. F. Han sp. nov.

Fig. 4

Etymology.

Refers to Guizhou Minzu University where this fungal type was isolated.

Type.

Guizhou Minzu University, Guiyang City, Guizhou Province, China 26°37'57"N, 106°62'41" E. Colonies form on PDA as a contaminating fungus, July 2022, Zhi-Yuan Zhang (dried holotype ZY H-22.001, ex-type ZY 22.001, ibid., ZY 22.002) .

Geographical distribution.

Guizhou Province, China.

Description.

Culture characteristics (14 days at 25 °C): Colonies on PDA 20-21 mm in diameter, white to light green, fluffy, nearly round, margin regular, exudates and diffusible pigments absent; reverse: claret-red to white from centre to margin. Colonies on MEA 23-24 mm in diameter, white, elevated at the centre, velvety to floccose, margin regular, exudates and diffusible pigments absent; reverse: pale yellow to white. Colonies on OA 27-28 mm in diameter, white, flat, nearly round, margin regular, exudates absent, producing a diffusible faint white pigment; reverse: white. Colonies on CMA 32-38 mm in diameter, khaki to white, radially sectored by cracks, powdery, exudates and diffusible pigments absent; reverse: khaki.

Hyphae hyaline, smooth, branched, septate, 1.0-2.5 μm in diameter. Sometimes lateral hyphae end in barrel-, reniform- or pyriform-shaped chains with blunt-ended arthroconidia, sometimes bearing aleurioconidia, sessile or stalked. Conidiophores abundant, solitary, erect, arising in acute angles with the main axis, hyaline, smooth, usually bearing verticils of two to three branches arising from the stipe at an acute angle. Aleurioconidia pyriform or obovoid, with a broad truncated basal scar, 3.0-5.0 × 2.0-2.5 µm (av. 3.6 × 2.7, n = 50), in conidiophores separated by connective cells, smooth or rough. Intercalary conidia barrel, reniform, pyriform to elongated or irregular, with a broad truncated scar at the base or both ends, 3.5-5.5 × 2.0-3.0 µm (av. 4.0 × 2.6, n = 50), smooth or rough. Arthroconidia not observed. Sexual morph unknown.

Notes.

Minnis and Lindner (2013) proposed multiple clades of Pseudogymnoascus and allies (clades A to O), based on phylogenetic analyses using North American isolates. In this study, Pseudogymnoascus campensis was placed in clade A (Fig. 1 ). Clade A harbours 13 isolates for which no morphological data are yet available and remain as unidentified species to date ( Minnis and Lindner 2013; Leushkin et al. 2015). These isolates were obtained from bat hibernacular soil in the USA ( Minnis and Lindner 2013). Pseudogymnoascus campensis (ZY 22.001 and ZY 22.002), 23014-1-I6 and 11MA03 formed an independent lineage with strong support (MLBS 100/PP 1, Fig. 1 ). The closest known species to Pseudogy. campensis are Pseudogy. shaanxiensis , Pseudogy. australis and Pseudogy. griseus , which are members of the neighbouring clade B ( Zhang et al. 2020b, Villanueva et al. 2021). However, Pseudogy. campensis can be distinguished from Pseudogy. shaanxiensis , Pseudogy. australis and Pseudogy. griseus by the absence of exudates on PDA, MEA and CMA media and lack of arthroconidia ( Zhang et al. 2020b; Villanueva et al. 2021).

Figures

Figure 1. Phylogram generated from a Maximum Likelihood analysis of sequences of Thelebolales, based on ITS and LSU. ML bootstrap values (≥ 75 %) and Bayesian posterior probability (≥ 0.75) are indicated along branches (BP / ML). The new taxa are highlighted in bold and blue and " T " indicate ex-type cultures.

Figure 4. Morphology of Pseudogymnoascus campensis sp. nov. a-d colony on PDA, MEA, OA and CMA after 14 d at 25 ° C (upper surface and lower surface) e, f fertile hyphae bearing arthroconidia and aleurioconidia g-k Conidiophore and Conidia. Scale bars: 10 μm (e-k).