Montagnula shangrilana 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 shangrilana Wanas. sp. nov.

Fig. 8

Etymology.

The specific epithet “shangrilana” refers to Shangri-La, Yunnan Province, where the holotype was collected.

Holotype.

HKAS 126539.

Description.

Saprobic on dead woody litter of Rhododendron sp. Teleomorph Ascomata 120-180 μm high × 150-210 μm diam., immersed to semi-erumpent, gregarious or rarely clustered, globose to subglobose, ostiolate. Ostiole 80-110 × 50-80 µm (x- = 100 × 64 μm, n = 6), papillate, central, straight, filled with hyaline cells. Peridium 10-20 μm thin on the sides and can reach up to 40 μm near the apex, with an outer layer consisting of heavily pigmented cells that have thick walls and exhibit a textura angularis arrangement at the apex, textura angularis texture at the sides; the innermost layer consists of hyaline compressed rows of cells. Hamathecium of 2-4.5 μm broad, dense, branched, cellular pseudoparaphyses. Asci 90-140 × 20-30 µm (x- = 116.2 × 24 μm, n = 10), bitunicate, fissitunicate, cylindrical-clavate, pedicel 25-40 μm long, 8-spored, uni to biseriate, with a minute ocular chamber best seen in immature ascus. Ascospores 48-60 × 17-22 µm (x- = 55.8 × 19.3 μm, n = 20), ellipsoidal to narrowly oblong, mostly straight, with conically rounded ends at the immature stage that become rounded when mature, golden-brown to dark brown, 3-septate, with large guttules in each cell, verruculose, surrounded by a thick mucilaginous sheath. Anamorph Undetermined.

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 a filiform margin, initially appearing whitish and transitioning to greenish gray, raised in the center. The colonies were grey at the center and a greenish gray towards the periphery and radiated 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, in a subalpine environment (this study).

Material examined.

China, Yunnan Province, Diqing Tibetan Autonomous Prefecture , Shangri-La (27.289707°N, 100.034477°E, 2744 m), on dead woody litter of Rhododendron sp. ( Ericaceae ), 22 August 2021, L. Qinxian, WTS8-2-2 (holotype, HKAS 126539), ex-type KUNCC 23-14434 ; ibid. (27.290007°N, 100.035233°E, 2833 m, WTS8-2 (HKAS 126538), living culture KUNCC 23-14433.

Notes.

In the combined SSU, LSU, ITS, tef 1-α, and rpb 2 phylogenetic analysis, two strains of Montagnula shangrilana (HKAS 126538, HKAS 126539) formed a monophyletic clade closely related to M. camporesii (MFLUCC 16-1369), M. cirsii (MFLUCC 13-0680), and M. scabiosae (MFLUCC 14-0954). While there were slight variations in size, shape, and color, all four species shared the common characteristic of 3-transversely septate ascospores. The sequence data of Montagnula camporesii , M. cirsii , and M. scabiosae showed no significant differences in their base pair comparisons, suggesting that they may be conspecific. Morphologically, these three species exhibited clavate asci and ellipsoid to fusiform, brown, overlapping, 3-septate ascospores. In contrast, our newly discovered species differed from these three species by 10/508 (1.96%) differences in the ITS region, 13/885 (1.5%) differences in the tef 1-α region, and 15/956 (1.56%) differences in the rpb 2 region (only M. camporesii possesses rpb 2).

Figures

Figure 8. Montagnula shangrilana (HKAS 126541, holotype) a ascomata on natural wood surface b vertical section through an ascoma c pseudoparaphyses d peridium cells e-h asci i-o ascospores (see verruculose feature of the ascospore in o). Scale bars: 100 μm (b); 10 μm (c, d, j-o); 20 μm (e-h).