Synchytrium endobioticum (Schilberszky) Percival

A fungal disease of potatoes has appeared in Prince Edward Island, Canada

IDENTITY
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Name: Synchytrium endobioticum (Schilberszky) Percival
Taxonomic Position:
Fungi: Chytridiomycetes: Chytridiales:
Common Names: potato wart disease

Significance:
The North American distribution of this fungal disease of potatoes was previously restricted to Newfoundland. Its presence was confirmed in Prince Edward Island on October 24, 2000.

Issues of Concern: Potato wart disease is caused by the soil borne fungus Synchytrium endobioticum, whose spores have been known to remain viable for up to 40 years. This disease produces unsightly growths on potato tubers, rendering them unmarketable.

There are 8 or more described potato wart fungus pathotypes, and the variety occurring on P.E.I. is currently being investigated.

Hosts: Primary Host: potato (Solanum tuberosum)
Wild Host: nightshade (Solanum spp.)
Secondary Host: tomato (Lycopersicon esculentum)

Distribution:
Europe (Austria, Belarus, Belgium, Czech Rep., Denmark, Estonia, Faeroe Islands, Finland, Germany, Hungary, Ireland, Italy, Latvia, Lithuania, Luxembourg, Netherlands, Norway, Poland, Portugal, Romania, Russian Federation, Slovakia, Slovenia, Sweden, Switzerland, Ukraine, United Kingdom, Yugoslavia); Asia (Armenia, Bhutan, China, India, Iran, Korea DPR, Korea Republic of, Lebanon, Nepal); Africa (Algeria, Egypt, South Africa, Tunisia, Zimbabwe); Oceania (New Zealand); North America (Newfoundland, Prince Edward Island); South America (Bolivia, Chile, Ecuador, Falkland Islands, Peru).

Quarantines: Potato wart disease is of quarantine significance to North America. It is also listed under EC Plant Health legislation as a quarantine organism.

Detection Strategies
Symptoms include the development of warty outgrowths or tumorous galls at the base of the stem. Aboveground galls are green to brown, becoming black at maturity and later decaying. Occasionally galls form on the upper stem, leaf, or flower. Belowground galls appear at stem bases, stolon tips, and tuber eyes. Tubers may be disfigured or completely replaced by galls. Subterranean galls are white to brown, becoming black through decay. Roots are not known to be attacked.

There are multiple methods of routine soil testing for viable winter sporangia. Soil samples from Prince Edward Island are being sieved, filtered, and microscopically examined for sporangia.

OTHER INFORMATION:
References:
Hampson, M.C. 1981. Wart, in Compendium of Potato Diseases, W.J. Hooker, ed. American Phytopathological Society, St. Paul, MN. pp. 36-37, includes plates.

Data Sheet. 1997. in Quarantine Pests for Europe, 2nd ed. CAB International, Wallingford, UK. pp. 925-929.

Useful Links:
CFIA datasheet
Agriculture and Agri-Food Canada Fact Sheet
AQIS factsheet

Related Documents:
Fact Sheet (USDA-APHIS-PPQ)    Synchyt.HTM


Phytosanitary Alert System
Pest Alert www.pestalert.org
Prepared on: 11/21/2000