Setophaeosphaeria microspora Z. F. Zhang & L. Cai (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-

Setophaeosphaeria microspora Z. F. Zhang & L. Cai (2020)

Fig. 10

Description.

Sexual morph undetermined. Asexual morph Conidiomata 170–240 µm, pycnidial, brown, globose, ostiolate, submerged or superficial on PDA. Setae brown, straight to slightly curved, thick-walled, smooth, septate, up to 160–250 µm long, 3.5–4.0 µm wide at broadest part. Pycnidial wall textura angularis to globulosa, brown to dark brown, multi-layers. Conidiogenous cells hyaline, subglobose, smooth-walled, 3.3–4.5 µm × 2.3–3.5 µm (x ̄ = 3.9 × 2.9 µm, n = 15). Conidia hyaline, cylindrical, obtuse ends, aseptate, with 2 small but obvious guttules, 3.2–4.0 µm × 1.3–1.7 µm (x ̄ = 3.7 × 1.4 µm, L / W ratio = 2.54, n = 30).

Culture characteristics.

Colony reaching 35 mm diam with dark grayish-green in center, beige in margin, velvety, entire edge, and similar to reverse side of the colony.

Material examined.

TAIWAN • Guanshan Township , Taitung County, 23°02'12.8"N, 121°11'22.0"E, serpentine soil in rice field, 2 nd November 2022, K. W Cheng, living culture NTUPPMCC 22-225 and NTUPPMCC 22-226 .

Notes.

The strains named NTUPPMCC 22-225 and NTUPPMCC 22-226 isolated in the present study clustered with ex-type strain Setophaeosphaeria microspora CGMCC 3.19301 with high statistical support, confirming their identification as Se. microspora (Fig. 11 ). However, Se. microspora ( NTUPPMCC 22-225 ) exhibited smaller conidiogenous cells than the type strain CGMCC 3.19301 (3.5–4.5 µm × 2.5–3.5 µm versus 7.0–10.0 µm × 2.5–4.0 µm) (Fig. 10 ; Zhang et al. 2020). This study represents the first report of Setophaeosphaeria in Taiwan.

Figures

Figure 10. Morphology of Setophaeosphaeria microspora NTUPPMCC 22-225. A, B 14 - days-old colony on PDA; C Squashed Conidiomata; D Setae; E Pycnidial wall; F, G Conidiogenous cells; H, I Conidia. Scale bars: 0.1 mm (C); 50 µm (D); 10 µm (E – I).

Figure 11. Maximum likelihood (ML) phylogenetic tree based on a concatenated dataset of ITS, LSU, and tub 2. In total, 14 strains representing 11 taxa were included in the concatenated dataset, with 1534 characters (ITS 482 bp, LSU 773 bp, and tub 2 279 bp) including alignment gaps. The tree was rooted with Pyrenochaetopsis americana UTHSC DI 16-225. 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.