Montagnula aquatica Y.R. Sun, Yong Wang bis and K.D. Hyde J.

Yang, Hongde, Thiyagaraja, Vinodhini, Jayawardena, Ruvishika Shehali, Chomnunti, Putarak, Zhao, Qi & Hyde, Kevin David, 2025, Three new records of Didymosphaeriaceae from Southwest China, Phytotaxa 710 (1), pp. 105-119 : 110-114

Montagnula aquatica Y.R. Sun, Yong Wang bis and K.D. Hyde J. Fungi 12(no. 738): 2 (2023) ( Fig 3 )

Index Fungorum number: IF900129; Facesoffungi number: FoF 12922

Saprobic on decaying wood. Sexual morph: Ascomata immersed to semi-erumpent, scattered, sub-globose to globose, visible black spots, uniloculate, ostiolate. Peridium 13–29 µm wide, composed of two layers of textura angularis cells; the outer layer consists of several layers of dark brown to black, thick-walled cells, while the inner layer is made up of several layers of hyaline, thin-walled cells. Pseudoparaphyses hyaline, numerous, filamentous, branched, and septate. Asci 109.7–133.9 × 16.4–19.2 μm (= 121.9 × 17.7 μm, L/W = 6.8, n = 10), 8-spores, bitunicate, fissitunicate, cylindrical to cylindric- clavate, pedicellate, with minute ocular chamber. Ascospores 25.7–30.6 × 7.3–11.0 μm (= 28.4 × 9.5 μm, L/W = 2.9, n = 35), overlapping biseriate, smooth-walled, curved, fusiform, widest at the center, 3- septate, slightly constricted in the middle septum, end conical and obtuse, hyaline at the beginning, became brown to dark brown when mature. Asexual morph: not observed.

Culture characteristics:— Colonies on PDA reached 14 mm in diameter after 5 days, surface white, flat, woolly, margin entire, reverse same color.

Material examined:— CHINA, Xizang, Nyingchi City, Motuo county (29°12′24″N, 95°9′30″E), elevation 1512 m, on decaying wood, host unidentified, 12 July 2022, Hongde Yang, HKAS: 135590, living culture KUNCC23- 15338.

Notes:— Montagnula aquatica was introduced by Sun et al. (2023) from Thailand in a freshwater habitat of submerged decaying wood. Subsequently, Wanasinghe et al. (2024) obtained collections from Honghe City, Yunnan Province, China, on dead woody litter of an unidentified plant and in a terrestrial habitat. Our sample was collected from Motuo County, Xizang, China, which is on the southern slopes of the eastern section of the Himalayas and belongs to tropical and subtropical climates with a high humidity environment. There are no base pair differences between our collection with the holotype (MFLU 22–0171) in ITS, LSU and SSU. However, our specimen has smaller ascospore size, measuring 25.7–30.6 × 7.3–11.0 μm in HKAS 135590, compared to 24–35 × 7.5–14 μm in MFLU 22–0171.

Montagnula guiyangensis Y.R. Sun, Yong Wang bis & K.D. Hyde , in Sun, Zhang, Hyde, Wang & Jayawardena, J. Fungi 12(no. 738): 5 (2023) ( Fig 4 )

Index Fungorum number: IF900130; Facesoffungi number: FoF 12923

Parasitic on the leaves of Michelia wilsonii . Asexual morph: Conidiomata developed from PDA, 160.3–505.0 μm high, 122.4–294.4 μm diam, pycnidial, immersed in the aerial hyphae, sub-globose to globose, with a central, necklike ostiolum, brown to dark brown, surrounded by pale brown to brown hyphal outgrowths. Macroconidiophores 4.1–6.8 μm long, 3.2–4.3 μm wide, cells sub-globose to cylindrical, hyaline, branched. Conidiogenous cells 3.7–8.5 μm long, 1.5–4.1 μm wide, hyaline, phialidic, ampulliform to doliiform, inflate at the base, terminal, intercalary, periclinal thickening visible. Macroconidia 3.3–4.5 × 1.9–2.8 μm (= 3.9 × 2.3 μm, L/W = 1.6, n = 50), ellipsoid to elongated-ellipsoid, aseptate, 1–2 larger oil-droplets, thick-walled and smooth, initially hyaline, become yellowish brown. Microconidia developed from immersed hyphae, 3.0–5.3 × 1.3–2.5 μm (= 3.8 × 2.0 μm, L/W = 1.9, n = 30), variable in shape, sub-globose, ellipsoid, obovoid, aseptate, smooth, hyaline to pale brown, 1 to 2 guttules. Sexual morph: Ascomata not observed in the cullture, few ascospores were observed. Ascospores 9.4–15.1 μm × 3.5–5.5 μm, ellipsoidal, 3-septate, constricted,dark colored at the septa, straight or slightly curved, smooth-walled, guttules, brown.

Culture characteristics:— Colonies on PDA reached 66 mm in diam after 30 days, initially the surface white, flat, woolly, margin entire, and the reverse white with dark brown in the central, surface became dark brown to black brown and the reverse got black when aging; Colonies on SNA reached 46 mm in diam. after 18 days, surface white, flat, concentric wrinkled, margin entire, reverse same colors; Colonies on WA sparse hypha, hyaline.

Material examined:— CHINA, Yunnan province, Kunming City, Panlong District, Kunming Botanical Garden (25°8′41″N, 102°44′21″E), elevation 1953 m, on the leaf lesion of the protected plant of Michelia wilsonii , 8 September 2021, Hongde Yang, HKAS: 135589, living culture KUNCC23-15159.

Notes:— The newly generated sequence data for KUNCC23-15159 cladded together with two strains of M. guiyangensis (HKAS 124556 and GUCC 22-0817). The base pair comparison between our isolates and the holotype (HKAS 124556) revealed 3 (460/464, 99%), 3 (820/823, 99%), and 1 (977/981, 99%) difference in the ITS, LSU, and SSU regions, respectively. Montagnula guiyangensis was introduced by Sun et al. (2023) based on its sexual morph, which is characterized by globose, uniloculate ascomata and fusiform, 2-celled ascospores with appendages. It was reported as a saprobe on twigs of Helwingia himalaica in a terrestrial habitat in Guizhou Province, China. In contrast, our collection represents the asexual morph of this species, which was isolated from leaf lesions of Michelia wilsonii . Most Montagnula species have been only reported in their sexual state. Crous et al. (2020) first described the asexual morph of M. cylindrospora as coelomycetous. Our isolate produced an asexual morph on PDA, representing the second asexual morph reported in the genus. Notably, our culture also produced microconidia, which is reported here for the first time in this genus.

Tremateia chromolaenae Mapook & K.D. Hyde , in Mapook, Hyde, McKenzie, Jones, Bhat, Jeewon, Stadler, Samarakoon, Malaithong, Tanunchai, Buscot, Wubet & Purahong, Fungal Diversity 101: 40 (2020) ( Fig. 5 )

Index Fungorum number: IF557365, Facesoffungi number: FoF 07794

Saprobic on dead stem Buddleja asiatica . Sexual morph: Ascomata 128.7–231.7 μm high, 166.7–375.9 μm in diameter, scattered, semi-immersed, or erumpent, coriaceous, dark brown to black, subglobose, ostiolate. Peridium 13.8–26.0 μm wide, comprising 2–3 layers of brown to dark brown cells of textura angularis. Hamathecium 2.3–3.4 μm wide, comprising hyaline, septate, and branched pseudoparaphyses. Asci 82.9–106.8 × 8.6–17.5 μm (= 97.1 × 12.5 μm, L/W = 7.7, n = 10), 8-spored, bitunicate, fissitunicate, cylindrical to clavate. Ascospores 17.8–23.3 × 8.5–11.6 μm (= 21.5 × 10.0 μm, L/W = 2.1, n = 30), overlapping 1–2-seriate, ellipsoidal, muriform, 3–5 transverse septate, constricted at the middle septum, with the upper part wider, 1–4 longitudinal septate, golden-brown, guttulate, ends acute or obtuse. Asexual morph: undetermined.

Material examined:— CHINA, Yunnan province, Wenshan City, Yanshan County (25°8′29″N, 102°44′16.4″E), elevation 1536 m, on the dead stem of Buddleja asiatica , 27 October 2021, Hongde Yang, HKAS: 135591.

Notes:— Tremateia included ten saprobic species from terrestrial or marine environments ( Devadatha et al. 2023). Our sample was morphologically and molecularly fit with the genus Tremateia . Tremateia chromolaenae was introduced by Mapook et al. (2020) from Thailand on dead stems of Chromolaena odorata . Four collections were reported by Zhang et al. (2023) from unidentified plant substrates in China. Moreover, one collection (HC106), obtained from leaf lesions, was deposited in GenBank with the host identified as Sonchus wightianus . This study provides the first report of T. chromolaenae in the Chinese traditional medicinal plant of Buddleja asiatica .

Figures

FIGURE 3. Montagnula aquatica (HKAS: 135590). a–c Appearance of ascomata on the substrate. d–e Section through ascomata. f Pseudoparaphyses. g–h, k Asci in water. i–j Asci in Cotton blue reagent. l–n Ascospores. o Gemmating ascospore. p Colony on PDA medium. Scale bars: d–e = 100 µm, f = 50 µm, g–h = 20 µm, i–j = 10 µm, k = 20 µm, l–n = 10 µm, o = 20 µm.

FIGURE 4. Montagnula guiyangensis (KUNCC23-15159). a Leaf lesions on leaves of Michelia wilsonii. b, c Conidiomata. d, e Macroconidiophores and conidiogenous cells. f, g Macroconidia. h–j Microconidiophores and microconidia. k Ascospore. l Colony on PDA. m Colony on SNA. Scale bars: c = 50 um, d, e = 5 μm, f = 10 μm, g = 5 μm, h = 50 μm, i = 20 μm, j, k = 10 μm.

FIGURE 5. Tremateia chromolaenae (HKAS: 135591). a, b Appearance of ascomata on the substrate. c Vertical section of ascoma. d Peridium. e Pseudoparaphyses. f–h Asci. i, j Ascospores. k Germinating of ascospores. Scale bars: c = 100 μm, d, e = 20 μm, f = 10 μm, g–i = 20 μm, j = 10 μm, k = 20 μm.