Kirschsteiniothelia tumidula 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

Kirschsteiniothelia tumidula H. L. Si, R. L. Chang, T. Bose & Y. C. Wang sp. nov.

Fig. 5 j – r

Etymology.

The name refers to the convex colony of this fungus 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 79 ), 13 Nov. 2020, H. L. Si, CX 79 B 2 = CGMCC 3.23629 (the ex-holotype culture), dried culture HMAS 352146 (holotype specimen), GenBank Accession Numbers: ITS OQ 645272 ; LSU OQ 645286 ; SSU OQ 645279 .

Description.

Hyphae smooth, olivaceous in colour, branched, septate, measuring approximately 1.78–4.76 μm (x ̄ = 2.61, n = 50) in diam (Fig. 5 i-o ). Conidiophores macronematous, mononematous, terminal or lateral, pale blue to olive green, smooth, unbranched, septate, measuring 34.07–70.85 × 5.11–10.06 μm (x ̄ = 50.63 × 7.17 μm, n = 11) (Fig. 5 m – o ). Conidiogenous cells monoblastic, integrated, terminal, determinate, spherical or ovoid in shape, surface smooth, pale blue to olive green in colour, measuring 4.95–11.61 × 4.39–10.51 μm (x ̄ = 8.82 × 6.14 μm, n = 11) (Fig. 5 m-p ). Conidia acrogenous, solitary, dry, pale olivaceous, pale at apex, septate, with 1–4 septa, slightly constricted at septum, obclavate, rostrate, smooth, straight or slightly curved, truncate at base, sometimes with a gelatinous sheath surrounding the apex, measuring 7.23–38.00 × 3.92–11.30 μm (x ̄ = 6.64 × 18.29 μm, n = 50) (Fig. 5 m – o ). No sexual morph was observed.

Culture characteristics.

On PDA, after 7 days of incubation at 25 ° C, the colony is pale bluish green in the centre, the edge is grey, the centre is raised, the surface is tomentose, and the margin is entire (Fig. 5 j ). The reverse of the colony is brown (Fig. 5 k ). The optimal growth temperature is 25 ° C (5.86 mm / day). Slow growth (1.42 mm / day) was observed at 5 ° C, and no growth was detected at 30 ° C and 35 ° C.

Host.

Usnea aciculifera .

Distribution.

Yunnan, China.

Note.

Kirschsteiniothelia tumidula is phylogenetically close to K. aquatica , K. cangshanensis , K. longisporum , K. pini , and K. weiningensis . However, the Conidiophores of K. tumidula ranges between 34.07–70.85 μm are shorter than those of K. aquatica , K. cangshanensis , K. longisporum , K. pini , and K. weiningensis which range between 105.5–135.5 μm, 114–151 μm, 115–285 μm, 69–124 μm, and 75–125 μm, respectively ( Bao et al. 2018; Jin et al. 2024; Tian et al. 2024; Xiao et al. 2025). Both K. tumidula , K. cangshanensis , and K. weiningensis exhibit a gelatinous sheath surrounding their apices, whereas K. aquatica , K. longisporum , and K. pini lack this feature. In addition, there is a significant variation in the ITS and LSU among these three species. There was a total of 37 bps (ITS: 34 bps, LSU: 3 bps, SSU: 0 bps) differences between K. tumidula and K. aquatica , 45 bps (ITS: 43 bps, LSU: 2 bps, SSU: 0 bps) differences between K. tumidula and K. cangshanensis , and 35 bps (ITS: 29 bps, LSU: 5 bps, SSU: 1 bps) differences between K. tumidula and K. longisporum , 39 bps (ITS: 36 bps, LSU: 3 bps, SSU: 0 bps) differences between K. tumidula and K. pini , and 43 bps (ITS: 36 bps, LSU: 6 bps, SSU: 1 bps) differences between K. tumidula and K. weiningensis .

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.