Left: Closeup of Syncephalis fuscata sporangium with a few attached merosporangia (100X). Right: Closeup of Syncephalis fuscata sporangium with spores that are dispersed in a drop of liquid at maturity (100X). Images by Dr. Gerald Benny

Several sporangia of Syncephalis fuscata (40X). Image by Dr. Gerald Benny

Syncephalis fuscata (Piptocephalidaceae, Zoopaginomycotina) is an obligate, haustorial mycoparasite that infects fungi in the Mucoraceae (Mucorales, Mucoromycotina). This species is morphologically characterized by sporophores with thin walls, basal rhizoids, and broadly ovoid vesicles.  The merosporangia are unbranched, multispored and are borne on the upper half or asymmetrically on the vesicle. The mature spores are released in a droplet of fluid that remains in the place originally occupied by the merosporangia. The initial indication of the presence of S. fuscata is the formation of extremely fine hyphae that completely cover the aerial hyphae of the host fungus.

Syncephalis fuscata originally was described by Indoh (1962) from garden soil collected in Tokyo, Japan and has also been isolated from dung. Syncephalis fuscata has since been reported from Argentina (Spinedi and Arambarri 1986) and the sequenced strain is from the United States (Georgia). This fungus is probably distributed globally in soil and dung. This and other species of Syncephalis have the potential to be used as biocontrol agents of Mucorales species that cause postharvest disease or wet rot (e.g. Choanephora cucurbitarum, Gilbertella persicaria, Mucor piriformis, Rhizopus stolonifer) of various fruit and vegetable crops. Sequencing of the Syncephalis fuscata genome is important because this species is a member of the Zoopagales (Zoopagomycotina), an evolutionary lineage that remains severely understudied.  

Members of the genus Syncephalis are often overlooked when encountered in nature. They are rarely isolated and difficult to maintain in culture because they grow best in co-culture with the host fungi. However, the genome of Syncephalis fuscata was generated based on a pure-culture isolate that was grown on a specialized calf-liver medium developed by Ellis (1966).

REFERENCES

Ellis JJ. 1966. On growing Syncephalis in pure culture. Mycologia 58:465−469.

Indoh H. 1962. Studies on Japanese Mucorales I. On the genus Syncephalis. Science  Reports of Tokyo Kyoiku University, Section B, 11: l-26.

Spinedi HA, Arambarri AM. 1986. Mucorales microparasitos en suelo de bosque de Nothofagus sp. Darwiniana 37:305-313.