Veronaea brunneicolor H. L. Si, R. L. Chang, T. Bose & Y. C. Wang, 2025

Chang, Runlei, Yan, Zhaoqi, Jiang, Jibo, Wang, Yichen, Si, Hongli, Bose, Tanay & Miao, Congcong, 2025, Four novel endolichenic fungi from Usnea spp. (Lecanorales, Parmeliaceae) in Yunnan and Guizhou, China: Taxonomic description and preliminary assessment of bioactive potentials, MycoKeys 118, pp. 55-80 : 55-80

Veronaea brunneicolor H. L. Si, R. L. Chang, T. Bose & Y. C. Wang sp. nov.

Fig. 6 i – q

Etymology.

The name refers to the brown colony morphology on PDA.

Type.

China • Yunnan Province, Chuxiong Yi Autonomous Prefecture, Chuxiong City , Dayao County (26°32'71.54"N, 100°57'3.6"E), isolated from the medullary tissue of the lichen Usnea aciculifera ( SDCX 68 ), 13 Nov. 2020, H. L. Si, CX 68 C 101 = CGMCC 3.23628 (the ex-holotype culture), dried culture HMAS 352145 (holotype specimen), GenBank Accession Numbers: ITS OQ 645271 ; LSU OQ 645285 ; SSU OQ 645278 ; β-tubulin OQ 696284 .

Description.

Hyphae smooth, bluish-gray, septate, branched, measuring 1.24–3.75 μm (x ̄ = 2.57 μm, n = 50) in diam (Fig. 6 k, l ). Conidiophores arising laterally on hyphae, bluish-gray, septate, branched or unbranched, sometimes reduced to conidiogenous cells, measuring 11.43–83.85 μm (x ̄ = 38.50 μm, n = 10) (Fig. 6 m – o ). Conidiogenous cells holoblastic, polyblastic, integrated, terminal, determinate, cylindrical or ovoid, geniculate, smooth, grey, measuring 8.42–40.56 × 1.78–4.29 μm (x ̄ = 15.46 × 2.77 μm, n = 50) (Fig. 6 m – o ). Conidia solitary and smooth, cylindrical to ellipsoid, straight or slightly curved, apex obtuse, base acute with a prominent scar, pale brown in colour, usually uniseptate, rarely bi-septate, often constricted at septa, measuring 4.12–12.09 × 1.96–3.05 μ (x ̄ = 6.72 × 2.43 μm, n = 50) (Fig. 6 m – q ). No sexual morph was observed.

Culture characteristics.

On PDA, after 7 days of incubation at 25 ° C, the colony gray-brown in colour, flat, with a tomentose surface, margin entire, and partially immersed in the medium (Fig. 6 i ). The reverse of the colony is dark brown (Fig. 6 j ). The optimal growth temperature is 25 ° C (1.26 mm / day). No growth was detected at 5 ° C and 35 ° C.

Host.

Usnea aciculifera .

Distribution.

Yunnan, China.

Note.

Our phylogenetic analysis showed that all Veronaea species, including our isolates and the type species V. botryose , form a well-supported monophyletic clade distinct from Exophiala , supporting the placement of V. brunneicolor within Veronaea . Morphologically, our isolate also differs from Exophiala by producing solitary conidia (vs. slime-aggregated) and having holoblastic-polyblastic conidiogenous cells (vs. ampulliform) ( Carmichael 1967). Although E. nagquensis clustered within Veronaea , its separation from E. salmonis , the type species of Exophiala , suggests plausible misidentification. Veronaea brunneicolor is phylogenetically close to E. nagquensis . However, the conidia diam of V. brunneicolor is shorter than E. nagquensis (2.43 μm vs. 3.3 μm) ( Sun et al. 2020). Conidia of V. brunneicolor are uni- or bi-septate, whereas in E. nagquensis , they are aseptate. In addition, there was a total of 15 bps differences between V. brunneicolor and E. nagquensis in ITS (6 bps), LSU (2 bps), SSU (0 bps) and β-tubulin (7 bps) sequences.

Figures

Figure 6. Morphology of Neoroussoella annulata sp. nov. (HMAS 352142) a top and b reverse view of a 15 - day-old culture growing on a PDA c – h hyphae; Veronaea brunneicolor sp. nov. (HMAS 352145) i top and j reverse view of a 15 - day-old culture growing on a PDA k, l hyphae; m – o conidiophore with conidia p, q conidia. Scale bars: 5 μm.