Bambusicola dehongensis L.S. Han & D.Q. Dai, in Dong et al., Fungal Diversity (2025)

Index Fungorum number: IF 902609; MycoBank number: MB 902609; Facesoffungi number: FoF 17150; Fig. 1

Etymology – named after the location “Dehong” City from where the new taxon was first discovered.

Holotype – GMB-W1042

Saprobic on dead culms of bamboo. Sexual morph: Ascostromata solitary to gregarious, immersed, raised when mature, 1–2-loculate, pseudostromatic. Locules 350–590 µm high, 135–190 µm diam. (x̄ = 449 × 159 µm, n = 10), subglobose, ostiolate at the center. Peridium 10–20 µm, comprising host and fungal tissues, thick-walled, composed of several layers, brown cells of textura angularis. Hamathecium 1–2 µm wide, composed of hyaline, trabecular, anastomosing, branched pseudoparaphyses. Asci 95–120 × 12–15 µm (x̄= 118 × 13 µm, n = 20), 8-spored, bitunicate, fissitunicate cylindric-clavate, apically rounded with an apical chamber, with a short furcate pedicel. Ascospores 27–32 × 5–7 µm (x̄ = 30 × 6 µm, n = 20), overlapping uni- to bi-seriate, fusiform, curved, 1-septate, constricted at the septum, tapering at the ends, hyaline, guttulate, surrounded by a thin, inconspicuous mucilaginous sheath. Asexual morph: undetermined.

Culture characteristics – colonies on PDA reaching 2–3 mm diam. at 25 °C after 25 days, circular, furrowed towards the edge, mycelium dense and velvety, milky white in the above, reverse yellow.

Material examined – China, Yunnan Province, Dehong Dai and Jingpo Autonomous Prefecture, Mang City, Xuangang Village, on dead culms of Bamboo, 22 July 2023, L.S. Han & D.Q. Dai (GMB-W1042, holotype); ex-type culture, GMBCC1035; ibid., HLS90 (GMB-W1044, isotype); exisotype culture, GMBCC1036.

GenBank accession numbers – GMBCC1035 = ITS: PQ248944, LSU: PQ248946, SSU: PQ248948; GMBCC1036 = ITS: PQ248945, LSU: PQ248947, SSU: PQ248949.

Notes – the multi-locus phylogenetic analysis shows that B. dehongensis is closely related to B. autumnalis (Fig. 2). Based on a nucleotide base pair comparison, B. dehongensis exhibits differences in the sequences of ITS (20/453 bp 4.4%), LSU (9/799 bp, 1.1%), and SSU (2/1002 bp, 0.1%) compared to B. autumnalis (UESTCC 23.0001, ex-type). Morphologically, B. dehongensis resembles B. autumnalis in having cylindric-clavate asci, and fusiform, curved, hyaline, 1-septate ascospores with an inconspicuous sheath. However, B. autumnalis can be easily distinguished by its ascostromata with obvious multiple cracks and a central black papilla (Liang et al. 2023). In contrast, B. dehongensis is visible only as its raised ascostromata without obvious cracks or papilla. In addition, the asci of B. dehongensis are longer, which can reach up to 120 µm long at maturity, while they reach 102 µm long in B. autumnalis. Based on the morphological and phylogenetic studies,  B. dehongensis is introduced as a novel species within the genus.

Figure 1 – Bambusicola dehongensis (GMB-W1042, holotype). a Bamboo specimen. b, c Ascostromata on host substrate. d, e Vertical section of ascostromata. f Peridium. g Trabeculate pseudoparaphyses. h–k Asci. l–p Ascospores. q Germinating ascospore. r, s Colony on PDA, above (r) and below (s). Scale bars: d, e, g = 50 µm, f = 20 µm, h–k = 30 µm, l–q = 15 µm.

Figure 2 – Maximum likelihood consensus tree inferred from the combined SSU, LSU, ITS, rpb2, and tef1-a multiple sequence alignments. Bootstrap support values for maximum likelihood (ML, first value) equal to or greater than 60% and Bayesian posterior probabilities from MCMC analyses (BYPP, second value) equal to or greater than 0.95 are given above the nodes. The scale bar indicates expected changes per site. The tree is rooted to Sulcatispora acerina KT2982 and S. berchemiae KT 1607. Ex-holotype strains are indicated with “T”. The newly generated sequences are indicated in red.