Toxicocladosporium fusiforme X. Yu. Zhang, Q. Y. Zhang & B. Fan, 2025

Toxicocladosporium fusiforme X. Yu. Zhang, Q. Y. Zhang & B. Fan sp. nov.

Fig. 16 View Figure 16

Type.

CHINA • Jiangsu Province, Nanjing, Nanjing Forestry University, Baima Campus , fungal endophytes from Pinus thunbergii , May 2023, Ben Fan and Xiuyu Zhang, NF 414 ( holotype HMAS 354159 View Materials , culture ex-type CGMCC 3.28958 View Materials ) .

Etymology.

Derived from the Latin words “ fusiforme ”, referring to the fusiform conidia of this species.

Description.

Mycelium composed of septate, subhyaline to pale brown, smooth to warty, branched hyphae, 1.8–3.2 μm diam. Asexual state: Conidiophores arising from superficial mycelium, erect to sinuous, brown, unbranched, smooth or verrucous, subcylindrical, straight to flexuous, multi-septate, (21.2 –) 24.4–58.7 (– 78.2) × (2.1 –) 2.5–3.6 (– 3.9) μm. Conidiogenous cells are terminal, smooth, slightly verrucous, light brown, unseptate, subcylindrical, (4.8 –) 5.2–10.5 (– 11.7) × (2.1 –) 2.2–3.5 (– 3.7) μm. Conidia are terminal or lateral to the tips of hyphae or conidiogenous cells, smooth, transparent to light brown, without septa, fusiform, some of which are connected in series, (6.4 –) 6.5–7.9 (– 8.2) × (2.2 –) 2.4–3.3 (– 3.5) μm.

Culture characteristics.

Colonies on MEA surface flat to slightly raised at centre, yellow-green, fuzzy, and have intact edges; reverse dark brown. On OA, colonies are brown, fading toward the centre and edges. The optimal temperature is 25–30 ° C, reaching 13–16 mm diam in 10 d. At 35 ° C, the fungus shows slight growth, attaining a colony diameter of 3–5 mm within 10 days. No growth was observed at 5 ° C.

Notes.

The genus Toxicocladosporium was established by Crous et al. ( Crous et al. 2007 b) to accommodate cladosporium-like fungi characterised by “ dark, thick-walled, conidial and conidiophore septa, and lacking the typical coronate Cladosporium scar ” ( Bezerra et al. 2017). Species of Toxicocladosporium are widely distributed and capable of colonising a variety of substrates. Nearly all species in this genus exhibit a broad host range, and have been isolated from diverse sources including mold-infested paint and clinical specimens ( Crous et al. 2009 c; Crous et al. 2009 d; Crous et al. 2016 b). Phylogenetic analyses indicate that our new fungal strain of T. fusiforme , isolated from Pinus thunbergii , is nested within the Toxicocladosporium clade and closely related to T. immaculatum , from which it differs by 1.65 % (8 / 484 bp) in the ITS region. Morphologically, T. fusiforme is distinguished by its relatively long conidiophores (21.2–78.2 vs. 12-25 × 2.5-3.5 µm in T. immaculatum ).