Potato spindle tuber viroid detected for the first time in Dahlia sp. in the Netherlands
The NPPO of the Netherlands recently informed the EPPO Secretariat of the first detection of Potato spindle tuber viroid (Pospiviroid, PSTVd – EPPO A2 List) in dahlia, a plant which was not known to be a important host plant for PSTVd. At the end of August 2013, PSTVd was detected in a dahlia corm production field in the province of South Holland during phytosanitary controls carried out before export. The viroid was detected and identified in RNA extract from dahlia leaves, using RT-PCR and subsequent sequencing. No visual symptoms or damage caused by PSTVd were observed in the crop. The presence of PSTVd was confirmed in 17 lots out of all 80 tested lots of the grower under consideration. Further investigations (on all lots grown by the grower concerned and all 119 lots of 3 associated growers) have revealed that only this grower of dahlia corms was affected by PSTVd. This was further supported by a broader survey carried out in 100 dahlia fields (selected at random) and by the export certification testing records of 2012 whereby 130 samples tested negative. The NPPO stressed that the grower concerned is located in an area where cultivation of potatoes is prohibited. The origin of this infection in dahlia is unknown. Phytosanitary measures are being taken to eradicate PSTVd from dahlia production. All the grower’s contaminated lots will be destroyed. Other remaining lots from the same grower were put under official control and will be used only for sale to the final consumer or for flower production.
The pest status of Potato spindle tuber viroid in the Netherlands is officially declared as:
Transient in ornamentals. No records in 2012.
One outbreak in Dahlia sp. in 2013, under eradication.
Absent from the entire potato production chain (Solanum tuberosum) based on specific surveillance.
Incidental finding in tomato (Solanum lycopersicum) fruit production in 2013, under eradication.
Not known to occur in pepper (Capsicum).
Sources
NPPO of the Netherlands (2013-09).