NAME OF THE ORGANISM: Viruses (Mosaic symptoms and leaf roll virus together) (1VIRUD*)
GENERAL INFORMATION ON THE PEST
Name as submitted in the project specification (if different to the preferred name):
Pest category:
1- Identity of the pest/Level of taxonomic listing:
Is the organism clearly a single taxonomic entity and can it be adequately distinguished from other entities of the same rank?
No
Is the pest defined at the species level or lower?:
No
Can listing of the pest at a taxonomic level higher than species be supported by scientific reasons or can species be identified within the taxonomic rank which are the (main) pests of concern?
- Yes: Seed potato sector
If necessary, please list the species:
Six viruses are already specifically listed at the species level in the EU Marketing Directives for seed potatoes (Potato virus Y, Potato virus X, Potato virus M, Potato virus S, Potato virus A and Potato leaf roll virus). Another virus (TSWV) was specifically submitted as a candidate for the RNQP status by the IIA2 AWG. Ten additional viruses are listed in EPPO PM 4/28 Standard. Therefore the list is restricted to the leaf roll virus and to the viruses causing mosaic symptoms mentioned previously.
Is it justified that the pest is listed at a taxonomic rank below species level?
Not relevant
Conclusion:
- Not candidate: Seed potato sector
Justification (if necessary):
Mosaic symptoms and leaf roll virus together' is not a single taxonomic entity. Six viruses are already specifically listed at the species level in the EU Marketing Directives for seed potatoes (Potato virus Y, Potato virus X, Potato virus M, Potato virus S, Potato virus A and Potato leaf roll virus). Another virus (TSWV) was specifically submitted as a candidate for the RNQP status by the IIA2 AWG. Ten additional viruses are listed in EPPO PM 4/28 Standard. In the replies to the RNQP questionnaire, 2 EU Member States (FR and SI) and ESA considered this entry as important. FR considered that these viruses could be listed at a lower taxonomic level (ie detailed type of virus) but think it is important to keep such global tolerances for viruses in the regulation because they are mainly controlled through visual inspections of field on the basis of the visible symptoms on growing plants. Moreover, the symptoms are often similar and combinations of viruses can be present in plants. On the other hand, SI proposed to keep "Viruses (Mosaic symptoms and leaf roll virus together)" listed as a RNQP. Experts concluded that viruses should be listed individually. However the measures based on visual inspection of mosaic symptoms and leaf roll together should remain in the Marketing Directive.
HOST PLANT N°1: Solanum tuberosum (SOLTU) for the Seed potato sector.
Origin of the listing:
5 - Seed potato sector: Council Directive 2002/56/EC
Plants for planting:
Plants intended for planting, other than [true] seeds
CONCLUSION ON THE STATUS:
Disqualified: A listing of such symptoms as a RNQP is not possible under the RNQP definition: it is not a single taxonomic entity. However it is proposed to list the targeted viruses individually, and to maintain such a general requirement and threshold for all these viruses (Mosaic symptoms and leaf roll virus together) in the relevant Marketing Directive.
8 - Tolerance level:
Is there a need to change the Tolerance level:
?
Proposed Tolerance levels:
The technical judgment of the SEWG was that a 6% tolerance of visual symptoms in the growing seed crop is not sufficiently strict to ensure less than 10% virus disease in the subsequent ware crop. Either a tighter tolerance or other measures such as post-harvest tuber testing are required to achieve this objective.
9 - Risk management measures:
Is there a need to change the Risk management measure:
No
Proposed Risk management measure:
REFERENCES: