Diagnostic protocol for Potato Wart (Synchytrium endobioticum)
Published: Wed, 27 Mar 2013, 13:27Last updated: Mon, 11 May 2015, 16:38
Potato wart disease is caused by the soil-borne fungus Synchytrium endobioticum (Schilbersky) Percival (Chytridiomycetes: Chytridiales). The principal symptom is a warty, cauliflower-like gall which develops on tubers and tuber initials. The main cultivated host affected by potato wart is potato (Solanum tuberosum L.), although other wild Solanum species are known to be infected in Mexico. In addition, a number of Solanaceous crops (including tomato) and weeds have been artificially inoculated. Experimentally, this fungus can also infect species within the genera Nicotiana, Physalis, Capsicastrum, Datura, Duboisia, Hyoscyamus, Lycium, Nicandra and Schizanthus (DEFRA, 2011; Hampson, 1993). Potato wart can be destructive under favourable conditions and entire crops can be lost as a result of heavily infected potato tubers being virtually entirely converted to warts. The fungus targets meristematic tissue and infects all below ground parts of the plant except root tissue. In tubers, infection initially occurs in eye tissue and gradually spreads causing massive hypertrophy and hyperplasia, frequently involving the entire tuber. The tumour is composed of simple, large parenchyma cells crowded with starch grains and organised into a malformed and compressed foliar branch system. In near-immune potato cultivars, the warts remain superficial and scab-like, while in resistant potato cultivars the zoospore dies soon after invasion by necrotic abortion (hypersensitive reaction) of the infected tissue (Hampson & Proudfoot, 1974; Hooker, 1990; Pratt, 1976). Very long periods of survival of the winter sporangia prevent replanting of infested fields for up to 30 years or longer (Pratt, 1976). This diagnostic manual was developed based on available published methods, and in consultation with international experts. It describes potato wart symptoms and outlines a microscopic procedure to confirm the presence of S. endobioticum spores in potato tissue.
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Resource provide by:- NPPO of Australia
Author/Editor name and address: James Cunnington, Department of Primary Industries Private Mail Bag 15 Ferntree Gully Delivery Centre Victoria 3156
Type of contact: NPPO
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- Diagnostic protocol