Vaginatispora nypae Jayasiri, E.B.G. Jones & K.D. Hyde, Mycosphere 10(1): 84 (2019)

Index Fungorum number: IF 555558; MycoBank number: MB 555558; Facesoffungi number: FoF 05264; Fig. 1

Saprobic on submerged decaying wood. Sexual morph Ascomata 250–420 µm high, 210–270 µm diam. (x̅= 299 × 247 µm, n = 10), scattered to gregarious, immersed, coriaceous, dark brown to black, subglobose, ostiolate. Ostiole slit-like, elongated, with a pore-like opening, plugged by hyaline, filamentous hyphae, and occasionally lighter colour, periphysate. Peridium 30–60 µm wide, circular, symmetric, dark brown to black layers, somewhat flattened cells of textura angularis, inner stratum comprising hyaline cell layers of textura angularis. Hamathecium comprising numerous, filamentous, branched septate, pseudoparaphyses 1.5–2 µm wide (x̅= 1.8 µm, n = 30). Asci 80–108 × 13–15 µm (x̅=94 × 14.5 µm, n=20), 8-spored, bitunicate, fissitunicate, cylindrical-clavate, short-pedicellate, apex rounded with a minute ocular chamber. Ascospores 26–29×6–7 µm (x̅=27×6 µm, n=30), uni- to bi-seriate, overlapping, hyaline, fusiform with narrow, acute ends, 1-septate, slightly constricted at the septum, smooth-walled, guttulate, with a prominent mucilaginous sheath. Asexual morph Undetermined.

Culture characters – Conidia germinated on PDA within 24 h. Colonies on PDA reaching 3–4 cm diam., after 4 weeks at room temperature, colonies irregular, medium dense, brown to grey in top view with pale brown edge. Lower surface dark brown with radially arranges margin.

Material examined – THAILAND, Yasothon Province, Thai Charoen District, Kham Phi, on decaying wood submerged in a River, 13 November 2018, D.F. Bao, B154 (MFLU 20-0424, new record), living culture, MFLUCC 20-0101.

GenBank numbers – ITS=MZ490791, LSU=MZ501207, SSU=MZ490777, TEF1-α=MZ501207.

Notes – Vaginatispora nypae was introduced by Jayasiri et al. (2019), which was recorded from pericarp of fallen fruit of Nypa fruticans on terrestrial habitat in Thailand. Based on our phylogenetic analysis of combined LSU, SSU, ITS, TEF1-α and RPB2 sequence data, our isolate (MFLUCC 20-0101) clustered with the ex-type strain of Vaginatispora nypae (MFLUCC 18-1543) with 100% MLBS, 1.00 BYPP support (Fig. 2). Our isolate appears quite similar to V. nypae, in that they have similar shaped asci and ascospores. However, our isolate has larger asci (80–108×13–15 µm vs. 75–85×11–13 µm) and ascospores (26–29 × 6–7 µm vs. 22–26 × 10–13 µm), which may be explained by the different habitats (Fig. 1). Our isolate was collected from a freshwater habitat, while the strain of MFLUCC 18-1543 was collected from a terrestrial habitat. A comparison of the ITS and TEF1α nucleotides of V. nypae (MFLUCC 18-0245) and a new strain (MFLUCC 20-0101) revealed 2 bp (0.38%) and 6 bp (0.6%) nucleotide differences respectively. This indicates that our new strain is V. nypae (Jeewon and Hyde 2016). Therefore, we introduce this isolate as a new record of V. nypae from a freshwater habitat.

Figure 1 – Vaginatispora nypae (MFLU 20-0424, new record). a–c Ascomata on submerged wood. d Section of ascoma. e Ostiolar canal. f Peridium. g Pseudoparaphyses. h–l Asci. m–p Ascospore. q, r Culture on MEA from upper and lower views. Scale bars: a=1000 μm, b, c=200 μm, d=100 μm, e, f=50 μm, g–l=20 μm, m–p=15 μm

Figure 2 – Phylogenetic tree generated from maximum likelihood (ML) analysis based on combined LSU, SSU, ITS, TEF1-α and RPB2 sequence data for the species from Melanommataceae. Teichospora trabicola (C 134E) and T. rubriostiolata (TR 7) are used as the outgroup taxa. The dataset comprised 4379 characters after alignment including gaps (LSU=883 bp, SSU=966 bp, ITS=523 bp, TEF1-α=1001 bp and RPB2=1006 bp). The RAxML analysis of the combined dataset yielded a best scoring tree with a final ML optimization likelihood value of − 26352.113239. The matrix had 1530 distinct alignment patterns, with 26.20% undetermined characters or gaps. Estimated base frequencies were as follows: A=0.248486, C=0.247993, G=0.267004, T=0.236517; substitution rates AC=1.626883, AG=4.007531, AT=1.289884, CG=1.323552, CT=8.595651, GT=1.000000; gamma distribution shape parameter α=0.180969. Support values for maximum likelihood (MLBS, left) above than 75% and Bayesian posterior probabilities (BYPP, right) greater than 0.95 are given at the nodes. Ex-type strains are in bold and newly generated sequence is in blue