Pseudoxylomyces aquaticus W. Dong, H. Zhang & K. D. Hyde (2020)

Cheng, Kai-Wen, Yang, Jiue-in, Srimongkol, Piroonporn, Stadler, Marc, Karnchanatat, Aphichart & Ariyawansa, Hiran A., 2025, Fungal frontiers in toxic terrain: Revealing culturable fungal communities in Serpentine paddy fields of Taiwan, IMA Fungus 16, pp. e 155308-e 155308 : e155308-

Pseudoxylomyces aquaticus W. Dong, H. Zhang & K. D. Hyde (2020)

Fig. 5

Description.

Sexual morph undetermined. Asexual morph Conidia produced on carnation leaves and on the surface or submerged in WA. Conidiophores short (7–13.5 µm) or absent. Conidiogenous cells holoblastic. Conidia solitary, orange-brown when immature, turn brown in mature, occasionally with paler end cells in pale brown, broadly fusiform, most 5 thick and obvious septa (few 3–4 septa), rough, thick-walled, 37.6–50 µm × 11.8–17 µm (x ̄ = 44 × 14.5 µm, L / W ratio = 3.05, n = 20).

Culture characteristics.

Colony reaching 30 mm diam with dark grayish-brown in the center, pale brown to gray in margin, velvety, rough surface, entire edge, and similar to reverse side of the colony.

Material examined.

TAIWAN • Wanrung Township , Hualien County, 23°42'40.3"N, 121°24'48.2"E, serpentine soil in rice field, 2 nd November 2022, K. W. Cheng, living culture NTUPPMCC 22-223 .

Notes.

Pseudoxylomyces aquaticus was previously documented on submerged wood in Thailand. Our study recovered a single strain ( NTUPPMCC 22-223 ) that clustered in a strongly supported clade (100 % / 1.00) with the ex-type strain ( KUMCC 17-0312 ) established by Dong et al. (2020), confirming its identity as Ps. aquaticus (Fig. 6 ). In this study, we observed the immature conidia with 3 to 4 septa showing more orange-brown in color (Fig. 5 C, D ), a feature not described in previous study ( Dong et al. 2020). In addition, this is the first discovery of the Pseudoxylomyces species in Taiwan.

Figures

Figure 5. Morphology of Pseudoxylomyces aquaticus NTUPPMCC 22-223. A, B 14 - days-old colony on PDA; C, D Immature conidia and conidiophores; E, F Conidia. Scale bars: 20 µm (C – F).

Figure 6. Maximum likelihood (ML) phylogenetic tree based on a concatenated dataset of ITS, LSU, SSU, and tef- 1. In total, 12 strains representing seven taxa were included in the concatenated dataset, with 2920 characters (ITS 526 bp, LSU 845 bp, SSU 643 bp, and tef- 1 906 bp) including alignment gaps. The tree was rooted with Corynespora cassiicola CBS 100822. MLB ≥ 70 % and BPPs ≥ 0.95 were shown at each node; values lower than these thresholds are indicated by a hyphen (–). The scale bar indicates the number of estimated substitutions per site. The strains introduced in this study are in red and novel species are in bold. The ex-type strains are marked with T.