Montagnula thevetiae Wanas., MycoKeys 101: 215 (2024)

Index Fungorum number: IF 850096, Facesoffungi number: FoF 16954  Fig. 1

Saprobic on dead stems of unidentified host. Sexual morph: Ascomata 290 – 320 µm high × 248 – 267 µm diam (x̄ = 310 × 260 μm, n = 20), immersed, solitary, scattered, globose, coriaceous, yellowish brown to brown, ostiolate. Ostiole central, cylindrical, papillate, protruding from substrate. Peridium 28–48 µm wide, comprising 2 – 3 layers of thin-walled, yellowish brown to light brown cells of textura angularis. Hamathecium comprises 2 – 3 µm wide, cylindrical to filiform, septate, branching pseudoparaphyses. Asci 95 – 173 ×19 – 32 µm (x̄ = 132 × 25 μm, n = 20), 8-spored, bitunicate, cylindric-clavate, slightly curved, with a short pedicel. Ascospores 32 – 44 µm long × 7 – 16 µm wide (x̄ = 38 × 11 μm, n = 20), broadly fusiform to ellipsoid, widest at the center, yellow to white when immature and reddish-brown when mature, hyaline at appendage at both ends, straight to slightly curved, 1-septate, with 2 large guttules at the center when immature, smooth-walled. Asexual morph: Undetermined.

Material examined – Thailand, Chiang Mai Province, in the forests around the Mushroom Research Center (19° 07.200’ N, 98° 44.044’ E), unidentified dead branch, 14 November 2022, ZL Tun, MRC85, (MFLU 24-0002).

Distribution: —Thailand.

GenBank accession numbers: — ITS = XXX, LSU = XXX and tef-1α = XXX.

Notes: — Based on the phylogenetic analysis, our strain (MFLU 24-0002) clustered with the strains of M. thevetiae (HKAS 126964, HKAS 126963) (Figure 1). and it is morphologically similar to M. thevetiae (Wanasinghe et al. 2024). The ITS and LSU and tef-1α regions are identical. Our strain (MFLU 24-0002) lacks rpb2 and SSU sequences for the base pair comparisons. Our new collection has overlapping characteristics compared to M. thevetiae isolates, including immersed, globose, subglobose and ellipsoidal ascospores that are straight to curved, brown, and 1-septate. Thus, we identify our isolate is M. thevetiae. We introduce our new isolate as a geographical record.

FIGURE 3. Montagnula thevetiae (MFLU 24-0002). a Hots substrate. b Immersed ascomata in the host surface. c Vertical section of an ascoma. d Peridium. e Ostiole. f Pseudoparaphyses. g–i Asci. j–m Ascospores (immature to mature). Scale bars: b = 250 μm, c = 50 μm d = 20 μm, e, f = 4 μm, g–i = 50 μm, j – m = 20 μm.

FIGURE 1. A phylogram was generated from RAxML based on a concatenated dataset of partial SSU, LSU, ITS, tef-1α, and rpb2 sequences of representative Montagnula taxa. Bootstrap support for ML > 75% and Bayesian posterior probabilities (PP) ≥ 0.95 are shown at each node. Hyphen (-) represents support values below 75% ML and 0.95 PP. Neokalmusia jonahhulmei (KUMCC 21-0818, KUMCC 21-0819) were used as the outgroup. Type strains are in bold and the new isolate is in red.