Acrogenospora thailandica J. Yang & K. D. Hyde, Fungal diversity 96: 78 (2019)

Fig. 5

Description.

Saprobic on rotting wood in freshwater. Sexual morph: Undetermined. Asexual morph: Hyphomycetous. Colonies sparse, scattered, hairy, black, glossy. Mycelium mostly submerged, composed of black, branched, smooth, 2–4 µm wide hyphae. Conidiophores 204.5–506 × 5–9.5 µm (x ̄ = 399.5 × 7, n = 30) macronematous, mononematous, solitary, erect or curved, pale to dark brown, paler towards the apex, septate, smooth. Conidiogenous cells holoblastic, monoblastic, integrated, pale brown, cylindrical, integrated. Conidia 21–34.5 µm (x ̄ = 25.5, n = 50) diam., thick-walled, smooth, spherical or subspherical, Olive-green to dark brown, sometimes with a large guttule, truncate at the base.

Cultural characteristics.

Conidia germinating on PDA within 24 h and germ tubes produced from the conidial base. Colonies on PDA growing slowly, reaching 23 mm diam in 24 days at 25 ° C in natural light, round, hairy, surface with dark grey-green aerial mycelium, margin entire.

Material examined.

China • Jiangxi Province, Yichun City, Fengxin County, Dagang Forest Farm, 28.627°N, 114.943°E, at an altitude of 362 m, on decaying wood submerged in a freshwater stream, 5 May 2020, Z. J. Zhai, DGS- 2 (HFJAU 10111), living culture JAUCC 5530.

Notes.

Phylogenetic analysis of the combined ITS, LSU, SSU, RPB 2, and TEF 1 - α sequences showed that our new strain JAUCC 5530 clustered together with the ex-type strain of A. thailandica (MFLUCC 17-2396) with high statistical support (100 % ML, 1.00 PP; Fig. 1). Morphologically, JAUCC 5530 shared similar conidial size with MFLUCC 17-2396 but possessed shorter (204.5–506 μm vs. 850–950 μm) conidiophores (Hyde et al. 2019). However, there were only 0.21 % (1 / 472 bp, excluding gaps) nucleotide differences in ITS sequences, 0.72 % (6 / 828 bp, excluding gaps) in LSU sequences, no differences in SSU sequences, and 0.58 % (6 / 1026 bp, excluding gaps) in RPB 2 sequences. Therefore, we identified our isolate as A. thailandica. The holotype of A. thailandica was originally described from submerged decaying wood in a freshwater habitat in Thailand. In the present study, this species is newly reported from submerged decaying wood in freshwater habitats in Jiangxi Province, China, representing its first record from the country.