Montagnula menglaensis Wanas., 2024

Wanasinghe, Dhanushka N., Nimalrathna, Thilina S., Qin Xian, Li, Faraj, Turki Kh., Xu, Jianchu & Mortimer, Peter E., 2024, Taxonomic novelties and global biogeography of Montagnula (Ascomycota, Didymosphaeriaceae), MycoKeys 101, pp. 191-232 : 191

Montagnula menglaensis Wanas. sp. nov.

Fig. 7

Etymology.

The specific epithet “menglaensis” refers to Mengla County, Yunnan Province, where the holotype was collected.

Holotype.

HKAS 130318.

Description.

Saprobic on dead culms of Indocalamus tessellatus (Munro) Keng f. Teleomorph Ascomata 200-300 μm high × 240-320 μm diam., immersed, gregarious or rarely clustered, globose to subglobose. Peridium 10-25 μm thin with an outer layer consisting of heavily pigmented cells that have thick walls and exhibit a textura angularis texture at the sides and base; the innermost layer consists of narrow, hyaline compressed rows of cells. Hamathecium of 3-7.5 μm broad, dense, branched, cellular pseudoparaphyses that are swollen at some septa. Asci 60-80 × 9-11 µm (x- = 71 × 9.8 μm, n = 15), bitunicate, fissitunicate, cylindrical-clavate, pedicel 15-30 μm long, 8-spored, uni to biseriate, with a minute ocular chamber best seen in immature ascus. Ascospores 10.5-14 × 4.5-5.5 µm (x- = 12.6 × 5.1 μm, n = 20), ellipsoidal, mostly straight, with conically rounded ends, golden-brown to dark brown, 1-septate and constricted at the septum, upper cell wider than the lower cell, with large guttules in each cell, verruculose, and surrounded by a thin mucilaginous sheath which is thicker at both ends. Anamorph Coelomycetous on PDA. Conidiomata pycnidial, gregarious, immersed to superficial, globose to subglobose, dark brown to black. Pycnidial wall thin, composed of brown cells of textura angularis. Conidiogenous cells did not observed. Conidia 2.3-3.3 × 1.4-2 μm (x- = 3 × 1.7 μm, n = 30), hyaline, aseptate, round to oblong or ellipsoidal, with small guttules.

Culture characteristics.

Ascospores germinated on PDA within 24 h. Following a two-week incubation period at 25 °C, the colonies on PDA medium reached a diameter of 5 cm. These colonies exhibited an undulate margin, initially appearing creamy whitish and transitioning to orange, raised in the center. The colonies were orange at the center and a creamy orange towards the periphery when observed from the reverse side.

Habitat and distribution.

This species is found in terrestrial habitats of Yunnan, China, inhabiting dead woody twigs of deciduous hosts (this study).

Material examined.

China, Yunnan Province, Xishuangbanna , Mengla County (21.588394°N, 101.435042°E, 776 m), on dead culms of Indocalamus tessellatus , 29 January 2022, L. Qinxian, ML23-7-3 (holotype, HKAS 130318), ex-type KUNCC 23-14424 ; ibid. 21.589178°N, 101.435752°E, 782 m, ML23-7-2 (HKAS 130316), living culture KUNCC 23-14422 ; ibid. ML23-7-5 HKAS 130317), living culture KUNCC 23-14423 .

Notes.

Montagnula menglaensis is described as a novel species based on its holomorph. The anamorph of Montagnula is rarely encountered; however, Crous et al. (2020) recently reported Montagnula cylindrospora based on its anamorphic features. The conidia of Montagnula menglaensis resemble to those of M. cylindrospora , although the latter fungus exhibits a more cylindrical shape.

Figures

Figure 7. Montagnula menglaensis (HKAS 130318, holotype) a-c ascomata on natural wood surface d, e vertical section through ascomata f, g pseudoparaphyses h peridium i-k asci l, m ascospores (see verruculose feature of the ascospore in n) o, p culture characters on PDA (o = above, p = reverse) q, r conidiomata s pycnidial wall t conidia. Scale bars: 100 μm (d, e); 10 μm (f-h, l-n, s, t); 20 μm (i-k).