Akanthomyces zaquensis Y.H. Wang, W.J. Wang, Ke Wang, C.H. Dong, J.R. Hao, P.M. Kirk & Y.J. Yao

Wang, Yong-Hui, Wang, Wen-Jing, Wang, Ke, Dong, Cai-Hong, Hao, Ji-Rong, Kirk, Paul M. & Yao, Yi-Jian, 2023, Akanthomyces zaquensis (Cordycipitaceae, Hypocreales), a new species isolated from both the stroma and the sclerotium of Ophiocordyceps sinensis in Qinghai, China, Phytotaxa 579 (3), pp. 198-208 : 203-204

Akanthomyces zaquensis Y.H. Wang, W.J. Wang, Ke Wang, C.H. Dong, J.R. Hao, P.M. Kirk & Y.J. Yao , sp. nov. ( Figs. 2–4 )

Fungal Names registration: FN570746 .

Etymology:— zaquensis , referring to the collecting site near the Za Qu River.

Colonies on PDA were rapidly growing, attaining a diameter of 25–28 mm and 30–34 mm within 10 days at 20 and 25 ºC, respectively, round, flat, white. Reverse primrose to pale yellow. Colonies on MEA and PCA attained a diameter of 23–28 mm and 28–31 mm within 10 days at 20 and 25ºC, respectively, round, flat, white. Reverse pale yellow ( FIGURE 2 ). The vegetative hyphae on PDA medium were delicate, hyaline, smooth-walled, 0.4–2.0 μm wide. Phialides occurring directly on the aerial hyphae; simple, 8.0–40.0 µm long, rarely over 100 µm, 0.6–1.2 µm at the base, tapering to about 0.4 µm at the tips. The conidia produced on the three media were one-celled, smooth-walled, hyaline; (1.5–)3.0–6.0(–7.0) × 0.5–1.2(–1.5) µm; adhering in heads at the apex of the phialides, long-ellipsoidal to almost cylindrical ( FIGURE 3 ).

The optimum temperature for growth was 5–37 ºC on three media (17–34 mm diameter in 10 d at 15–30 ºC), little growth (usually less than 10 mm diameter) at ≤10 ºC, no growth at ≥ 33 ºC ( FIGURE 4 ).

Notes: Akanthomyces zaquensis was isolated from O. sinensis . The species differed from A. lecanii by having bigger conidia. Furthermore, A. zaquensis produced single and lanceolate or narrowly lageniform phialides directly from the aerial hypha.

Sexual state:—Unknown.

Holotype:— CHINA. Qinghai Province: Yushu Prefecture, Zadoi County, Sulu Country , Duoxiao Village beside the Za Qu River , isolated from both the stroma and the sclerotium of O. sinensis on the ground, 20 May 2002, J.J. Li (holotype HMAS 246915, ex-holotype living culture CGMCC 19934).

Other material examined:— CHINA. Qinghai Province: Yushu Prefecture, Zadoi County, Sulu Country , Duoxiao Village beside the Za Qu River , from both the stroma and the sclerotium of O. sinensis on the ground, 20 May 2002, J.J. Li (isotype HMAS 246914, isotype HMAS 246916, isotype HMAS 246917) .

Figures

FIGURE 2. Akanthomyces zaquensis (CGMCC 19934). a–b. Strains grown on different media after 10 days at 20 °C; c–d. Strains grown on different media after 10 days at 25 °C. Scale bars: a–d = 2 cm.

FIGURE 3. Akanthomyces zaquensis (CGMCC 19934) on PDA, similar to those on MEA and PCA. a–d. Phialides and conidia; e–f. conidia. Scale bars: a–f = 10 μm.

FIGURE 4. Akanthomyces zaquensis (CGMCC 19934). a. obverse colony side on PDA at different temperatures; b. reverse colony side on PDA at different temperatures; c. obverse colony side on MEA at different temperatures; d. reverse colony side on MEA at different temperatures; e. obverse colony side on PCA at different temperatures; f. reverse colony side on PCA at different temperatures. Scale bars: a–f = 2 cm.