Pseudoplagiostoma inthanonense V. S. Hittanadurage Silva, R.H. Perera, and Gomes de Farias, 2023

Hittanadurage Silva, Veenavee S., Perera, Rekhani H. & Gomes De Farias, Antonio R., 2023, Addition to Pseudoplagiostomataceae: Pseudoplagiostoma inthanonense sp. nov. from Doi Inthanon National Park, Northern Thailand, Phytotaxa 625 (1), pp. 66-76 : 70-72

Pseudoplagiostoma inthanonense V. S. Hittanadurage Silva, R.H. Perera, and Gomes de Farias , sp. nov.

Figure 2

Index Fungorum Number: IF 901198 Faces of Fungi: FoF 15022

Etymology— inthanonense derived from “Doi Inthanon”, a National Park Reserve in northern Thailand where the specimens were collected.

Holotype — MFLU 23-0345

Saprobic on broadleaf species leaf litter. Sexual morph: Undetermined. Asexual morph: Coelomycetous. Conidiomata: 80–140 µm height, 70–120 µm diameter (x̅ = 103 × 109 µm, n = 5), pycnidial, exuded conidia as pale-yellow drops, solitary, immersed, globose to subglobose, moderate to dark brown, emerging through the plant tissue. Conidiomata walls: 5–10 µm wide, comprising 2–3 layers of thin-walled, yellowish brown, pseudoparenchymatous cells, forming textura angularis and intermixed with the host cells at the base and sides. Paraphyses: 0.9–2 µm wide, branched, septate, hyaline. Conidiophores: reduced to conidiogenous cells; Conidiogenous cells 3.3–12.3 × 1–2.7 µm (x̅ = 7 × 1.7 µm, n = 25), arising from the inner cell layer, phialidic, cylindrical to lageniform, hyaline, smooth-walled. Conidia: 14–22.6 × 6.4–10.2 µm (x̅ = 17.5 –8.5 µm, n = 60), mainly ellipsoid, oblong, oval, reniform or pyriform, aseptate, with an obtuse apex and protruding scar at the tapering base, straight or slightly curved, guttulate, hyaline, thick-, smooth-walled ( Figure 2 ).

Culture characteristics: Colonies on MEA reaching 22 mm diam. after 4 days at 20–25 °C, above white, becoming whitish grey when mature, reverse white with yellowish green center reaching charcoal grey center with creamy colour margins, mycelium medium spares to medium when mature, sporulated after 30 days, spore exudate, circular, effuse to raised, entire, velvety, slightly irregular margin, not producing pigmentation. Colonies on PDA reaching 19 mm diam. after 102 days at 20–25 °C, above white, reaching whitish grey when mature, reverse yellowish grey, medium, convex, lobate margin, wrinkled folded.

Material exsamined: Thailand, Chiang Mai Province, Doi Inthanon National Park Reserve, Huai Sai Lueang Waterfall area , on a leaf of diseased unknown broadleaf species, 30 November 2022, V. S. Hittanadurage Silva, V049, holotype MFLU 23-0345 , ex-type living culture MFULCC 23-0262 .

GenBank accession numbers: ITS: OR606510 ; LSU: OR633320 ; tef1α: OR650831 ; tub2: OR611920 ; rpb2: OR611921

Notes— Pseudoplagiostoma inthanonense is phylogenetically related to P. mangiferae ( Figure 1 ). The holotype of P. mangiferae was collected from a living leaf of Mangifera in China ( Phookamsak et al. 2019). However, P. inthanonense is distinguished by possessing smaller conidia and conidiogenous cell sizes. Furthermore, the shape of P. inthanonense conidiogenous cells differs from that of P. mangiferae , displaying a cylindrical to lageniform. Compared to P. dipterocarpicola , described in Thailand, P. inthanonense exhibits larger spore size and wider conidiogenous cells ( Tang et al. 2022). A comprehensive comparison of values is presented in Table 4 . The pairwise sequence comparisons showed that P. inthanonense is distinguished from P. mangiferae by 18/520 bp (3.46%, gaps two bp) in ITS, 3/778 (0.38 %, gap zero pb) in LSU and 39/439 (8.88%, gap two bp) in tub2. Therefore, based on the morphological, phylogenetic, and molecular evidence, we introduce P. inthanonense as a new species.

Figures

FIGURE 1. Bayesian inference (BI) phylogram of Pseudoplagiostomaceae based on a concatenated ITS, LSU, rpb2, tef1α and tub2 sequence alignment, with Apoharknessiaceae as the outgroup. Ultrafast bootstraps ≥75% and Bayesian posterior probabilities ≥0.95 are shown at the first and second positions, respectively. The strain obtained in the present study is in blue. The scale bar at the centre-bottom represents 0.04 substitutions per site.

FIGURE 2. Pseudoplagiostoma inthanonense. (MFLU 23-0345, holotype). a = Host substrate. b, c = Pycnidia with conidial exudates. d = Cross section of the conidioma. e = Conidiomata wall. f = Paraphyses. g–k = Conidiogenous cells with attached conidia. l–p = Conidia. q = Germinated conidium. r = Culture in PDA media. s = Culture in MEA media. t = Spore masses on cultures in MEA media. Scale bars: d–f, q = 20 µm, g–p = 10 µm.