Annulohypoxylon spougei Suwannasai, M. P. Martín, Phosri & Whalley

Rathnayaka, Achala R., Chethana, K. W. Thilini, Manowong, Areerat, Bhagya, Amuhenage T., Win, Hsan, Tun, Zaw L., Mapook, Ausana & Hyde, Kevin D., 2025, Taxonomy, phylogeny, and bioactive potential of Xylariales (Sordariomycetes, Ascomycota) from Thailand: novel species discovery, new host and geographical records, and antibacterial properties, MycoKeys 120, pp. 35-117 : 35-117

Annulohypoxylon spougei Suwannasai, M. P. Martín, Phosri & Whalley , Persoonia 44: 353 (2020)

Fig. 7

Description.

Saprobic on Antidesma madagascariense dead wood. Sexual morph: Ascostromata 1–3 cm long × 0.3–2 cm broad and 0.8–1.2 mm thick (x ̄ = 2 × 1.4 × 1 mm, n = 10), hemispherical, effused-pulvinate, shiny, surface black, carbonaceous. Ascomata 0.25–0.6 mm high × 0.25–0.5 mm diam. (x ̄ = 0.4 × 0.3 mm, n = 10), immersed in the stroma, subglobose to globose, black, ostioles papillate, encircled with a flattened, truncatum-type disc, 0.2–0.25 mm diam. (x ̄ = 0.23 mm, n = 8). Hamathecium 3–5 μm wide, comprising long, hyaline, unbranched, septate paraphyses. Asci 27–42 × 2–3 μm (x ̄ = 36 × 2 μm, n = 20), the spore-bearing parts 17–25 µm long with stipes 9–15 µm long, 8 - spored, unitunicate, cylindrical, with an apical ring bluing in Melzer’s iodine reagent. Ascospores 7–9 × 3–4 μm (x ̄ = 7.6 × 3.6 μm, n = 40), uniseriate, one-celled, inequilaterally ellipsoidal, with narrowly rounded ends, hyaline when immature, becoming brown at maturity, guttulate. Asexual morph: Undetermined.

Culture characters.

Ascospores germinated on the PDA within 24 hours at 25 ° C. Germ tubes are produced from both sides of the ascospore. Colonies on the PDA reaching 1.5–2.0 cm diam. after five days at 25 ° C, circular in shape, white at first, cottony, white color in the front view, brown in the middle, and pale brown at the margin of the reverse view.

Material examined.

Thailand • Chiang Rai, near Ang Kep Nam Huai Luang Than Thong Reservoir , on decaying wood of Antidesma madagascariense ( Phyllanthaceae ), 05 July 2024, Achala Rathnayaka, AA 24 ( MFLU 24-0525 ); living culture MFLUCC 24-0607 .

Known distribution and hosts.

China (rotten wood) ( Ke et al. 2024); Thailand (on corticated wood, Antidesma madagascariense ) ( Crous et al. 2020; this study).

Notes.

According to the multi-gene phylogenetic analyses (ITS, LSU, β-tub, and rpb 2), our strain ( MFLUCC 24-0607 ) clustered with the ex-type strain of A. spougei ( SWUF 09-032 ) with 100 % ML bootstrap and 1.00 PP support (Fig. 2 ). Our fungal collection ( MFLUCC 24-0607 ) exhibits morphological characteristics similar to the holotype of A. spougei ( SWUFH 099 ), including black, shiny carbonaceous ascostromata; 8 - spored, unitunicate, cylindrical asci, with an apical ring that bluing in Melzer’s iodine reagent; and unicellular, inequilaterally ellipsoidal, brown ascospores ( Crous et al. 2020). However, the ascospores of the A. spougei holotype show a straight germ slit along the full length of the spore, which is not observed in our isolate ( MFLUCC 24-0607 ). Based on the morpho-molecular evidence, we identified our collection as a new host record of A. spougei on Antidesma madagascariense in Thailand.

Figures

Figure 2. Astrocystis bambusae on a dead twig of Bambusa vulgaris (MFLU 24-0522, a new host record). a. Substrate; b, c. Appearance of stromata on the host; d. Cross section of the stroma; e. Peridium; f. Paraphyses; g – j. Asci; k. Ascus apical apparatus (stained in Melzer’s reagent); l – q. Ascospores; r. Ascospores with sheath; s, t. Colony on the PDA (s upper, t lower). Scale bars: 5 mm (b); 1 mm (c); 500 μm (d); 20 μm (f – j); 10 μm (e, k – r).

Figure 7. Annulohypoxylon spougei on dead wood of Antidesma madagascariense (MFLU 24-0526, a new host record). a. Substrate; b, c. Appearance of ascostromata on the host; d. Ostiolar discs in ascomata (indicated by arrows); e. Horizontal section through the ascomata; f. Paraphyses; g-i. Asci; j. Apical apparatus stained blue with Melzer’s reagent; k-p. Ascospores; q. Germinated ascospores; r, s. Colony on the PDA (r upper, s lower). Scale bars: 2 mm (b); 500 μm (c, d); 200 μm (e); 20 μm (f); 10 μm (g – i, q); 5 μm (j – p).