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

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

Fig. 5 View Figure 5

Etymology.

Named after the location from which it was collected, Pubei, Guangxi Zhuang Autonomous Region, China.

Holotype.

HKAS 134950 View Materials .

Description.

Endophytic from healthy leaves of Aquilaria sinensis . Sexual morph: Undetermined. Asexual morph: Hyphae 3–6 µm diam. branched, smooth, septate, hyaline, or subhyaline. Conidiophores 1–4 µm diam, micronematous, solitary, subcylindrical, hyaline to pale grey, smooth, 0–2 - septate, branched or not, usually reduced to conidiogenous cells. Conidiogenous cells 5–6.3 × 6.3–11.3 µm diam. (x ̄ = 5.8 × 9.4 µm, n = 20), discrete, solitary, monoblastic, determinate, subglobose, straight, smooth, hyaline or dark brown. Conidia 6–14 μm diam (x ̄ = 11.3 µm, n = 20), solitary, granular, 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, black, reaching 9 cm in 7 days at 30 ° C; mycelium partly superficial, partly immersed, slightly effuse, radially striate, with irregular edge, initially grayish white, 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 , in healthy living leaves of Aquilaria sinensis , September 25, 2020, Shiyu Zhang, GX 2-2 ( HKAS 134950 View Materials , holotype). Ex-type living culture at KUNCC 23-16745 .

Notes.

Nigrospora pubeiensis is described herein as a new species, which resembles other species in the genus in having granular, dark brown to black, globose, or subglobose conidia, but differs in its short conidiophores, sometimes reduced to conidiogenous cells. The strain representing N. pubeiensis ( KUNCC 23-16745 ) clustered in a supported clade (100 % ML, 1 PP) and is closely related to N. guangxiensis ( KUNCC 23-16747 ) and N. chinensis (CGMCC- 38127). However, N. pubeiensis is distinct in nucleotide base pair comparison with N. guangxiensis ( KUNCC 23-16747 ) across the ITS gene region (9 / 511 bp, 1.8 % difference, no gap) and the TEF 1-α gene region (62 / 425 bp, 14.5 % difference, no gap), TUB 2 (0); it differs with N. chinensis (CGMCC- 38127) across the ITS gene region (3 / 492 bp, 0.6 % difference, no gap) and the TUB 2 gene region (26 / 365 bp, 7.1 % difference, no gap), TEF 1-α (0). They also have different conidiophore structures. Compared with the photoplate from Wang et al. (2017), the conidiophore of N. chinensis has an ampulliform structure, but N. pubeiensis does not. Based on distinct morphological characteristics and phylogenetic support, we regard this isolation ( KUNCC 23-16745 ) as a new species, N. pubeiensis , which was collected from Aquilaria sinensis in Guangxi Province, China.