Absidia pateriformis M. F. Tao, H. Zhao & X. Y. Liu, 2024

Tao, Meng-Fei, Ding, Zi-Ying, Wang, Yi-Xin, Zhang, Zhao-Xue, Zhao, Heng, Meng, Zhe & Liu, Xiao-Yong, 2024, Unveiling species diversity within early-diverging fungi from China II: Three new species of Absidia (Cunninghamellaceae, Mucoromycota) from Hainan Province, MycoKeys 110, pp. 255-272 : 255-272

Absidia pateriformis M. F. Tao, H. Zhao & X. Y. Liu sp. nov.

Fig. 4

Type.

China • Hainan Province, Ledong County, Jianfengling National Forest Park (18.74540 ° N, 108.96716 ° E), from soil, 13 Oct 2023, M. F. Tao and X. Y. Liu, holotype HMAS 352926 , ex-holotype living culture CGMCC 3.27495 , living cultures XG 06347-1 or SAUCC 6347 D-1 .

Etymology.

The pateriformis (Lat.) refers to its bowling-like projections.

Description.

Mycelia white at first and gradually turning to light brown, aseptate or septate, branched. Rhizoids well-developed, root-like, simply branched. Stolons hyaline, branched, smooth, 4.4–9.2 µm in diameter. Sporangiophores growing on stolons, erect or slightly bent, mostly unbranched or simply branched, smooth, single or 2–4 in whorls, 33.4–156.5 µm long, 2.7–6.8 µm wide. Sporangia globose to pyriform, smooth, hyaline, deliquescent-walled, 16.8–30.6 µm long, 11.2–26.7 µm wide, and with a septum 9.4–20.6 µm below sporangia. Apophyses obvious, gradually widening from the base to the top, 3.8–11.4 µm wide at the base and 7.1–24.3 µm wide at the top, light brown, hyaline. Collars absent or present. Columellae mostly globose, occasionally oval, 10.9–25.1 µm long, 8.2–21.0 µm wide. Projections obvious, bowling-like, hyaline, single, 3.3–6.7 µm long, 1.2–4.0 µm wide. Sporangiospores smooth, hyaline, oval or globose, 3.1–4.2 µm long, 2.7–4.0 µm wide. Chlamydospores absent. Zygospores not found.

Culture characteristics.

Colonies on PDA at 25 ° C for 7 days, reaching 80 mm in diameter, exhibiting an average growth rate of approximately 10.7–11.4 mm / day, initially white, gradually becoming light brown and greenish when mature, regularly in reverse, petaloid at edge.

Maximum growth temperature.

30 ° C.

Additional specimen examined.

China • Hainan Province, Ledong County, Jianfengling National Forest Park (18.74540 ° N, 108.96716 ° E), from soil, 13 Oct 2023, M. F. Tao and X. Y. Liu, living culture XG 06347 D-2 , SAUCC 634702 or SAUCC 6347 D-2 .

Notes.

In the molecular phylogeny, A. pateriformis was closely related to A. jiangxiensis . Morphologically, the sporangiophores of A. pateriformis were at most four-wheeled and branched, while those of A. jiangxiensis were at most six-wheeled and unbranched. Additionally, the maximum length of the sporangiophores in A. jiangxiensis was significantly greater than that in A. pateriformis (156.5 µm vs 280.0 µm). The sporangia size was also smaller in A. pateriformis (16.8–30.6 × 11.2–26.7 μm vs 16.5–48 × 16.5–44 μm), with only one projection observed instead of two and a narrower columellae (8–21 µm vs 10–34 µm). Zygospores were not observed in A. pateriformis ( Zhao et al. 2023) .

Figures

Figure 4. Absidia pateriformis (holotype: HMAS 352926) a obverse and reverse of the culture on PDA b sporangiospores c rhizoids d columellae e – g sporangia. Scale bars: 10 μm (b – g).