GUIDELINES FOR THE DEVELOPMENT OF NEW METHODS FOR VIRUS TESTING OF FRUIT TREES AND SMALL FRUIT CROPS

At the 19^th International Symposium on Virus and Virus-like Diseases of Temperate Fruit Crops and the 10^th International Symposium on Small Fruit Virus Diseases it was decided that a protocol should be developed as an outline of what type of data needs to be obtained before a new test (Biological Indicators, Serological Tests, Molecular Test or other) will be accepted by the committee as a suitable method of detection for a specific virus. The data should be collected and there will be a session at subsequent symposia to present the data packet and have it evaluated. Once accepted by the committee it will be listed as an appropriate test in the proceedings of the meeting.

DATA REQUIRED FOR A NEW TEST TO BE CONSIDERED

Before a new method of detection will be accepted by the ISHS Working Group of Tree Fruit or Small Fruit Viruses the following data packet must be developed and presented to the committee for approval. Also, any new test must be as good as or better than the currently accepted test(s) for a specific virus before it will be approved.
Tests must be conducted over at least two years in three different locations. The new test must be compared to the currently accepted test(s) at each location for each year. The number of strains/isolates for which the test has been used must be recorded and the same strains/isolates tested by the currently accepted method of detection. The person or group proposing the use of the new test will be responsible for identifying collaborators in other countries to run the comparative tests. They must also assure that a reasonable number of strains/isolates are evaluated. There is not a defined number of strains/isolates that need to be tested since the number of recognized strains/isolates for each virus varies. The more complete the list of strains/isolates evaluated the more likely the test will be approved. Omission of well characterized strains/isolates of a virus from the testing will result in the test not being accepted.
The new test must be used in at least three different laboratories to ensure that it is robust enough to be used successfully in multiple settings and in multiple years to ensure the test will be effective under different environmental conditions. When appropriate the optimal time of year for testing needs to be identified in the data packet. For molecular tests the exact primer sequences must be included in the description of the test. For PCR based tests the exact size of the amplicons should be given. For serological tests the antiserum number (lot or rabbit id should be identified) or monoclonal/hybridoma must be identified. For biological indicators the indicator should be free of latent viruses that may restrict its movement or use in other countries unless it is demonstrated that a latent virus is required to get optimal symptom development.
The data should be collected by the person(s) proposing the new test and the results presented at the next Symposium of the ISHS Working Group of Tree Fruit and Small Fruit Viruses. A decision on the acceptability of the new test will be made at the symposium. If there are data gaps in the information a decision will be delayed until the following symposium.