Microlepicola guizhouensis J. Y. Zhang, K. D. Hyde & Y. Z. Lu, 2025

Zhang, Jing-Yi, Hyde, Kevin D., Yang, Ming-Fei, Sun, Ya-Ru, Xiao, Xing-Juan, Meng, Ze-Bin, Bao, Dan-Feng & Lu, Yong-Zhong, 2025, Discoveries of Dothideomycetes (Fungi) associated with pteridophytes in China, IMA Fungus 16, pp. e 167717-e 167717 : e167717-

Microlepicola guizhouensis J. Y. Zhang, K. D. Hyde & Y. Z. Lu sp. nov.

Fig. 7

Etymology.

The species epithet refers to the collecting site, Guizhou province, China.

Diagnosis.

Differs from species in Angustimassarina and Neobambusicola in the shapes of hamathecium, asci and ascospores.

Holotype.

HKAS 129777 .

Description.

Sexual morph: Ascomata deeply immersed, solitary or scattered, visible as dark spots that are slightly raised, which ascocarp passes through the thin host epidermis, exposing the mostly whole ascomata from lower side of the hosts. Ascomatal wall coriaceous, thin-walled, composed of brown cells of textura angularis to textura prismatica in surface view. Hamathecium filiform, remotely separate, pseudoparaphyses, hyaline, 1.3–2.6 µm wide. Asci 8 - spored, bitunicate, cylindric-clavate, straight or slightly curved, with a short pedicel, apically rounded, with an ocular chamber, 68–85 (– 91) × 10.5–15.5 µm ( x ̄ = 78 × 12.8 µm, n = 25). Ascospores overlapping, 2–3 - seriate, fusiform, straight or slightly curved, 1 - septate, not constricted at the septum, guttulate, 18.5–21.7 × 4–5.5 µm ( x ̄ = 20 × 4.7 µm, n = 25), surrounded by a thin and inconspicuous mucilaginous sheath. Asexual morph: Undetermined.

Culture characteristics.

Ascospores germinating on WA within 13 h at 26 ° C. Colonies on PDA, circular with entire margin, flat with raise in the center, dry, cotton, ashen in the center, khaki to grey towards the margin; light brown to brown-yellow from below, and not producing pigmentation in cultures.

Material examined.

CHINA • Guizhou Province, Qiandongnan Miao and Dong Autonomous Prefecture, Liping County, Yongcong Town , 26.0781942N, 109.1568557E, on dead fronds of Microlepia marginata ( Dennstaedtiaceae ) near a river in a forest, 27 March 2022, J. Y. Zhang, J 333 ( HKAS 129777 , holotype; GZAAS 23-0715 , isotype), ex-type living culture KUNCC 23-14007 .

Additional sequence.

ITS ( PV 862372).

Notes.

In the phylogenetic analysis, our new isolate ( KUNCC 23-14007 ) forms a monophyletic clade in Pleosporales . Microlepicola guizhouensis exhibits some morphological similarities with several groups in the Pleosporales , such as Angustimassarina and Neobambusicola , particularly in the shapes of the hamathecium, asci, and ascospores ( Thambugala et al. 2015; Mapook et al. 2020 a; Yu et al. 2024). However, these groups are phylogenetically distinct and also differ in some morphological characteristics. Microlepicola guizhouensis differs from the two aforementioned genera in having immersed ascomata with clearly visible epidermal cell composition, ranging from textura angularis to textura prismatica. To avoid establishing a new family for a single species, Microlepicola was introduced as a new monotypic genus and assigned to Pleosporales genera incertae sedis.

Figures

Figure 7. Microlepicola guizhouensis (HKAS 129777, holotype). A Host substrate; B Colonies on the host surface (arrows indicating ascomata); C, D Colonies from the lower side of the host epidermis; E Sectional view of the ascoma; F The surface of the ascoma; G, H Pseudoparaphyses; I – K Asci; L – Q Ascospores; R Pure culture. Scale bars: 30 μm (F, G); 10 µm (H, M – Q); 20 µm (I – L).