Bambusicola bambusae D.Q. Dai & K.D. Hyde, Cryptog. Mycol. 33(3): 372 (2012)
Index Fungorum number: IF 801046; MycoBank number: MB 801046; Facesoffungi number: FoF 11797; Fig.1
Saprobic on decaying wood in a freshwater stream. Ascomata 135–175 µm high × 190–245 µm diam. (x̄ =155×216 µm, n=10), solitary, scattered to gregarious, immersed under the host tissue, conical in section, brown to dark brown, coriaceous, subglobose, ostiolate. Ostiole crestlike, central, elongated to papillate, with a pore-like opening, plugged by hyaline, filamentous hyphae. Peridium comprising host and fungal tissues, 17–31 μm thick, composed of brown to dark brown cells of textura angularis intermingled with host cells. Hamathecium composed of numerous, filamentous, hyaline, septate, branched, 1.0–1.5 μm, pseudoparaphyses. Asci 55–75×7.5–9.5 μm (x̄ =66.3×8.5 μm, n=20), 8-spored, bitunicate, fissitunicate, cylindrical, with a shallow apical chamber and a short furcate pedicel. Ascospores 19–21×4.0–4.5 μm (x̄ =20×4.5 μm, n=30), 2–3-seriate, 1-septate, constricted at the septum, slightly broad fusiform, tapering towards the ends, occasionally with large upper cell, with narrowly rounded ends, hyaline, guttulate, smooth-walled.
Culture characteristics – Ascospores germinating on PDA within 24 h and germ tubes produced from both ends. Colonies growing on PDA, reaching a diam. of 20–25 mm after 20 d at 25 °C, surface smooth to velvety, with entire to slightly undulate edge, greenish in the centre, white at the edge; reverse dark greenish to black in the centre, white at the edge.
Material examined – Thailand, Tao Ngoi, Sakon Nakhon, on decaying wood submerged in a river, 12 November 2017, D.F. Bao, B110 (MFLU 22–0080), living culture, MFLUCC 22–0021.
Host/Substrate – Bamboo (Poaceae) (Dai et al. 2012); decaying wood submerged in a river (this study) Distribution: Thailand (Dai et al. 2012; this study)
GenBank numbers – ON764309 (ITS); ON764310 (LSU); ON764313(SSU); ON788004 (rpb2)
Notes – In the phylogenetic analysis, our new isolate B110 clustered with the ex-type strain of Bambusicola bambusae (MFLUCC 11–0614) with 98% ML/1.00 BYPP support (Fig. 2). The morphology of our collection is almost identical to the holotype of Bambusicola bambusae except for the size of ascomata and the sheath of the ascospores. The ascomata of our collection are smaller than the holotype (190–245 vs. 450–70 µm diam) and the holotype of B. bambusae has ascospores with a thick sheath (Dai et al. 2012), whereas, the sheath of ascospores were not observed in our collection. A comparison of the ITS and rpb2 gene regions of MFLUCC 11–0614 and B110 revealed 0 and 3 base pair differences and therefore we identified our new collection as Bambusicola bambusae as recommended by Pem et al. (2021). Bambusicola bambusae was described by Dai et al. (2012), it was collected on bamboo from terrestrial habitats in Thailand. Our collection was from freshwater habitats and this is the first time this species reported from freshwater habitats.
Figure 1 – Bambusicola bambusae (MFLU 22-0080, new record). a–c ascomata on wood d section of ascomae peridium, f, g ostiole. h pseudoparaphyses. i–k asci. l–p ascospores. q Germinating ascospore. r, s culture on PDA from surface and reverse. Scale bars: b, f = 100 μm, e = 50 μm, g = 30 μm, h–k = 20 μm, l–q = 10 μm
Figure 2 – Phylogram generated from ML analysis, based on combined ITS, LSU, SSU, tef1 and rpb2 sequence data for Bambusicolaceae. The combined dataset comprises 37 strains with 4617 characters including gaps (LSU: 854 bp, SSU: 1016 bp, ITS: 805 bp, tef1: 950 bp, rpb2: 992 bp). The tree is rooted with Murilentithecium lonicerae (MFLUCC 18–0675) and M. clematidis (MFLUCC 14–0561). Maximum likelihood bootstrap values≥75% and baysian BYPP≥0.95 are displayed on the nodes, respectively. Newly introduced taxa are indicated in red. Ex-type and representative strains are in bold