Thyridaria thailandica Z. L. Tun & K. D. Hyde, 2024

Thyridaria thailandica Z. L. Tun & K. D. Hyde , sp. nov.

( FIG 4 View FIGURE 4 )

Index Fungorum number: IF 902650, Facesoffungi number: FoF 16953

Etymology:—The name reflects the country where the specimen was collected, Thailand.

Holotype:—MFLU 24-0001

Saprobic on unidentified decaying wood. Sexual morph: Ascomata 420–470 µm high × 350–368 µm wide (x̄ = 417 × 361 μm, n = 5), immersed, erumpent, aggregated, clustered, globose to subglobose, uniloculate, dark brown to black, ostiolate, yellow to reddish or orange-brown pruinose layer and masses spores surrounding the apices of the ostiolar necks. Ostiole papillate, protruding from the center of the ascomata, thick, yellowish around apical pore. Peridium 45–60 µm wide (x̄ = 51 μm, n = 5), comprising several layers of dark brown cells of textura angularis. Hamathecium comprises 1–2.3 µm wide, cylindrical, filamentous, rarely branched, septate, anastomosed, hyaline, branched trabeculate pseudoparaphyses. Asci 50–100 × 9–13 µm (x̄ = 75 × 12 μm, n = 20), 8-spored, bitunicate, cylindric-clavate to clavate, slightly curved, short pedicellate, apically rounded. Ascospores 17–20 × 7–10 µm (x̄ = 20 × 8.4 μm, n = 20), overlapping uni-to bi-seriate, ellipsoid to obovoid, slightly curved, golden brown to chestnut brown, 3-septate, severely constricted and darker at the septa, guttulate, 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), on fallen unidentified decaying branches, 14 November 2022, ZL Tun, MRC87, (MFLU 24-0001, holotype).

GenBank accession numbers:— ITS = PQ529134, LSU = PQ529136, rpb 2 = PQ594790 and SSU = PQ529135.

Notes:— Based on the multi-gene phylogenetic analysis, our new strain Thyridaria thailandica (MFLU 24-0001) clustered with T. aureobrunnea (MFLUCC 21-0090) with 100% ML and 1.00 PP bootstrap support with forming the basal clade of the genus ( Fig 2 View FIGURE 2 ). Thyridaria thailandica can be distinguished from T. aureobrunnea by having larger ascomata (420–470 × 350–368 µm vs. 248–294.5 × 262–286.5 µm), wider asci (48–98 × 9–13 µm vs. 45–61.5×7–8.5 µm), and ascospores (17–20 × 7–10 µm vs. 10.5–13× 3.5–4.5 µm) ( Boonmee et al. 2021). A comparison of the interspecies genetic distances between T. thailandica and T. aureobrunnea resulted in the following differences: 2.19% in ITS (546 base pairs) and 0.80% in LSU sequences (871 bp). Thyridaria aureobrunnea lacks rpb 2, and SSU sequences to compare the base pairs. Therefore, based on the variations in morphology, genetic distances, and the phylogenetic species recognition criteria proposed by Chethana et al. (2021), and Pem et al. 2021), we establish T. thailandica (MFLU 24-0001) as a new species. It is important to note that the pseudoparaphyses are trabeculate sensu ( Liew et al. 2000).