Amphisphaeria falcata 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

Amphisphaeria falcata H. L. Si, R. L. Chang, T. Bose & Y. C. Wang sp. nov.

Fig. 5 a – i

Etymology.

The name refers to the sickle-shaped conidia.

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 diffracta ( SDCX 40 ), 13 Nov. 2020, H. L. Si, CX 40 A 8 = CGMCC 3.23740 (the ex-holotype culture), dried culture HMAS 352144 (holotype specimen), GenBank Accession Numbers: ITS OQ 645270 ; LSU OQ 645284 ; SSU OQ 625477 ; RPB 2 OQ 696281 ; and β-tubulin OQ 696283 .

Description.

Hyphae smooth, grey, septate, septa inconspicuous, compartments cylindrical, branched, measuring 1.19-3.15 μm (x ̄ = 1.93 μm, n = 50) in diam (Fig. 5 c – f ). Conidia hyaline, surface smooth, sickle-shaped, 25.07-42.22 × 1.12-2.43 μm (x ̄ = 31.83 × 1.76 μm, n = 11) in diameter (Fig. 5 g – i ). No sexual morph was observed.

Culture characteristics.

On PDA, after 10 days of incubation at 25 ° C, the colonies were white in colour, velvety on the surface, slightly raised in the centre, with an entire margin and irregular radial folds (Fig. 5 a ), and the reverse was yellow in the centre with a white halo around the margin (Fig. 5 b ). The optimum growth temperature was 25 ° C (1.42 mm / day). No growth was detected at 5 ° C and 35 ° C.

Host.

Usnea diffracta .

Distribution.

Yunnan, China.

Note.

Amphisphaeria falcata is phylogenetically close to A. verniciae . However, the sexual state of A. falcata has not been observed, and the conidia of A. verniciae have not been observed. There is a significant variation, a total of 297 bps, in the ITS, LSU, β-tubulin, and RPB 2 gene sequences between these two species (ITS 71 bps, LSU 15 bps, β-tubulin 162 bps, RPB 2 49 bps).

Figures

Figure 5. Morphology of Amphisphaeria falcata sp. nov. (HMAS 352144) a top and b reverse view of a 10 - day-old culture growing on a PDA c – f hyphae g – i conidia; Kirschsteiniothelia tumidula sp. nov. (HMAS 352146) j top and k reverse view of a 15 - day-old culture growing on a PDA l conidiophore m – o conidiophore with conidia p germinating conidia q, r conidia. Scale bars: 5 μm.