Detection of Potato spindle tuber viroid in potato breeding material in the Netherlands: an update
In the Netherlands, the presence of Potato spindle tuber viroid (Pospiviroid, PSTVd – EPPO A2 List) was confirmed in March 2014, in in vitro plantlets of one potato accession line (see EPPO RS 2014/088). Eradication measures were immediately implemented. The NPPO of the Netherlands recently provided the EPPO Secretariat with an update about the situation in this breeding company. Further testing (549 tests) was carried out and revealed that in total 10 potato accessions were infected by PSTVd. Five positive accessions came from the greenhouse and the other five positive accessions came from a plot of the breeding company where tubers from greenhouse-grown plants had been planted. All plant material having direct clonal relationships with infected accessions has been destroyed. All other potato material at the company has been destroyed or will be subjected to integral testing (testing of each individual plant). Investigations of all companies which have direct relationships with the affected breeding company are on-going. Since the beginning of the 1980s an official annual PSTVd testing scheme has been put into place for all newly registered varieties of second year pre-basic nuclear stock. In addition, all candidate material (each tuber or plant) intended for in vitro propagation is tested for PSTVd. Approximately 2 000 to 3 000 tests for PSTVd are completed each year on candidate potato material and in vitro propagation material. However, in order to further improve safeguards against the possible introduction of pospiviroids in the future, an intensified testing scheme will be completed by the end of July 2014 at all breeding companies in the Netherlands. Pending the outcome of these investigations, no breeding material will be exchanged between companies. Finally, the annual survey programme for regular seed potatoes will specifically target PSTVd in 2014.
The pest status of Potato spindle tuber viroid (on potato) in the Netherlands is officially declared as: Incidental finding in potato (Solanum tuberosum) at a breeding company. Under eradication.
NPPO of the Netherlands (2014-06).