Nigrospora guangxiensis S. Y. Zhang, J. F. Li & K. D. Hyde, 2025

Nigrospora guangxiensis S. Y. Zhang, J. F. Li & K. D. Hyde sp. nov.

Fig. 3 View Figure 3

Etymology.

Named after the type location, Guangxi Zhuang Autonomous Region, China.

Holotype.

HKAS 134952 View Materials .

Description.

Endophytic from healthy leaves of Aquilaria sinensis . Sexual morph: Undetermined. Asexual morph: Hyphae branched, septate, hyaline to pale brown, 1–3 µm diam. Conidiophores usually reduced to conidiogenous cells, which are dispersed on hyphae. Conidiogenous cells 4.5–6 × 5.3–7.3 µm diam. x ̄ = 5 × 6.8 µm, n = 30), discrete, solitary, monoblastic, determinate, subglobose, pale brown to brown colored. Conidia 8–14 μm diam. x ̄ = 10.5 µm, n = 30), solitary, discrete, dark brown to black, globose or subglobose.

Cultural characteristics.

Mycelium effusing on PDA within 12 hours from the edges of the surface sterilized leaf tissue piece. Colonies growing on PDA, hairy, reaching 9 cm in 7 days at 30 ° C; mycelium partly superficial, partly immersed, slightly effuse, radially striate, with irregular edge, initially greyish-brown, becoming black colored with age; asexual spores were formed after 25 days on PDA, and sexual spores not formed within 60 days on PDA.

Known distribution

(based on molecular data): China (this study).

Known hosts.

Aquilaria sinensis (this study).

Material examined.

China • Guangxi Zhuang Autonomous Region, Pubei city , on healthy living leaves of Aquilaria sinensis , September 25, 2020, Shiyu Zhang, GX 4-1 ( HKAS 134952 View Materials , holotype); extype living culture, KUNCC 23-16747 .

Notes.

In the multi-locus phylogenetic analyses, our strain Nigrospora guangxiensis ( KUNCC 23-16747 ) formed a separate branch basal (97 % ML, 1 PP) to N. pubeiensis ( KUNCC 23-16745 ) and N. chinensis (eight strains). Nigrospora guangxiensis differs from N. pubeiensis in having smaller conidiogenous cells (5 × 6.8 µm vs. 5.8 × 9.4 µm) and shorter conidia (10.5 µm vs. 11.3 µm). Additionally, its initial culture on PDA medium is greyish-brown. Nigrospora guangxiensis is distinct from N. chinensis in having smaller conidia (10.5 µm vs. 12.97 ± 1.07 µm), pale brown to brown-colored conidiogenous cells, and sterile cells, which are absent in N. guangxiensis ( Wang et al. 2017). A nucleotide base comparison of these species is shown in the notes of N. pubeiensis and Table 2 View Table 2 .