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Development of an effective strategy for on-farm eradication of potato ring rot - PH0170

This project will develop new detection methods for use in monitoring viable cells of the ring rot pathogen as to enable a study of aspects of its epidemiology leading to the development of a realistic eradication strategy for on-farm use.

Epidemiological work will include study of the pathogen’s ability to survive from one year to the next and to spread within and between farms and potato stores.

The principal techniques for monitoring the viable pathogen will be based on TaqMan and NASBA technology. It is hoped that a hybrid of the two, essentially an RNA NASBA reaction detected by TaqMan fluorescence based reactions, using molecular beacons will allow accurate quantification of the pathogen in substrates such as soil for which there are currently no methods available. If direct quantification is not applicable, the techniques will be used to detect critical threshold populations in the substrates.

This project will be of great value in assessment of risks so that confident eradication measures can be taken in the likely event of an outbreak of potato ring rot.
1. To compare the performance of NASBA and TaqMan-PCR with the best established methods (including plating on the best available selective media) for quantitative detection of viable Cms in selected substrates including potato tubers, soil and on dried surfaces such as metal. This study will determine the optimum method for assessing population increases and decreases in selected environmental situations.

2. To use the selected method(s) to monitor Cms population changes in microplants and stored seed potatoes of susceptible and tolerant cultivars.

3. To use the selected method(s) to monitor decline of Cms populations in various substrates (soil, water, on metal, wood and rubber surfaces) in response to key environmental factors such as temperature, humidity (where relevant), pH, solarisation (where relevant).

4. To use the selected method(s) to monitor population decline in different soil types, different types of potato waste, various components of sewage eg sludge and effluent.

5. To determine whether weed species play a role in survival of the pathogen.

6. To determine whether other crops, (mainly root crops) such as sugar beet in which Cms has been previously found in latent infections, pose any significant epidemiological role in Cms survival and spread.

7. To determine the best chemical disinfectants for disinfecting wood, metal, plastic and rubber surfaces.

8. To determine whether insects and nematodes can transmit viable Cms cells from crop to crop within fields, farms and stores.

9. To write a series of recommendations for eradication measures to be taken in an outbreak situation.
Project Documents
• Final Report : Final Report   (62k)
• Executive Summary : Executive Summary from final report   (26k)
Time-Scale and Cost
From: 2000

To: 2003

Cost: £124,563
Contractor / Funded Organisations
Central Science Laboratory
Alien Species              
Disease Control              
Plant health              
Plant Pests and Diseases              
Plants and Animals              
Fields of Study
Plant Health