Annulohypoxylon bahnphadengense

Annulohypoxylon bahnphadengense J. Fourn. & M. Stadler, Fungal Diversity 40: 30 (2010)

Index Fungorum number: IF 512545; Facesofungi number: FoF 17293.

Saprobic on the dead wood of Berrya cordifolia. Sexual morph: Ascostromata 3–14 × 2–10 × 0.5–0.2 mm (x̄ = 7 × 6 × 0.3 mm, n = 8), effused-applanate, superficial, pulvinate to hemispherical, clustered, hard-textured, shiny, surface black, carbonaceous. Ascomata 0.5–3.5 mm high × 0.3–0.5 mm diam. (x̄ = 2 × 0.4 mm, n = 15), immersed in the stroma, subglobose to globose, black, ostiolate, papillate, encircled with a flattened truncatum-type disc 0.2–0.25 mm diam. (x̄ = 0.22 mm, n = 10). Peridium 40–60 μm wide, composed of several layers of hyaline to dark brown cells of textura angularis. Hamathecium 4–6 μm wide, comprising long, hyaline, unbranched, septate paraphyses. Asci 54–130 × 3–5 μm (x̄ = 94 × 4.5 μm, n = 20), 8-spored, unitunicate, cylindrical, short pedicellate, with an apical ring bluing in Melzer’s reagent. Ascospores 6–8 × 3–4 μm (x̄ = 7.5 × 3.5 μm, n = 40), uniseriate, one-celled, inequilaterally ellipsoidal, with narrowly rounded ends, hyaline when immature, becoming light brown to dark 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 2.0–2.5 cm diam. after six 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 in the reverse view.

Material examined: Thailand Chiang Rai, Phan District, Sai Khao, forest area near Wat Udom Waree, on decaying wood of Berrya cordifolia (Malvaceae), 05 July 2024, Achala Rathnayaka, AA28 (MFLU 24-0526); living culture MFLUCC 24-0608.

GenBank numbers: PQ860996 (LSU), PQ861001 (ITS), PQ878514 (rpb2)

Notes: Morphologically, our collection (MFLUCC 24-0608) shows similar characteristics to the holotype of A. bahnphadengense (MFU08-1552), including shiny, black, carbonaceous ascostromata; 8-spored, cylindrical, short-pedicellate asci with an apical ring bluing in Melzer’s reagent; and uniseriate, one-celled, inequilaterally ellipsoidal, ascospores with narrowly rounded ends (Fournier et al. 2010b). According to the multi-gene phylogenetic analyses (ITS, LSU, β-tub, and rpb2), our strain (MFLUCC 24-0608) clusters with the ex-type strain of A. bahnphadengense (STMA 13115) with 89% ML bootstrap and 0.84 PP support. Based on the morpho-molecular evidence, we identified our collection as a new host record of A. bahnphadengense on Berrya cordifolia in Thailand.

Figure 1. Phylogram generated from ML analysis based on the combined dataset of ITS, LSU, β-tub, and rpb2. The tree is rooted to Biscogniauxia petrensis (HKAS102388). Bootstrap support values for ML ≥ 70% and Bayesian posterior probabilities (PP) ≥ 0.90 are noted at the nodes. Strain numbers are noted after the species names. Strains isolated in this study are represented in blue, and type strains are in bold.