Incursion of Potato spindle tuber viroid on tomatoes in Belgium
In Belgium, tomato plants (Lycopersicum esculentum) showing severe growth reduction with chlorosis and distortion of the young leaves were observed in one glasshouse, in August 2006. As the disease had been spreading slowly along the row, it suggested the presence of a viroid. A sample was collected and laboratory analysis (RT-PCR, sequencing) revealed the presence of Potato spindle tuber viroid (Pospiviroid, PSTVd – EPPO A2 List). Investigations were carried out to trace the origin of this infection. It was found that in November 2005, 8-day-old tomato seedlings raised from seed by a Dutch nursery were transferred to a small part of the glasshouse of the Belgian grower; 7 to 8 weeks later, the plants were transplanted to their final destination. In May 2006, the grower first observed growth reduction in a single plant; several weeks later, similar symptoms were observed in two more plants in the same row close to the first symptomatic plant; and by September, there were approximately 20 symptomatic tomato plants, all located in two adjacent rows. This PSTVd outbreak was fully eradicated by destroying all tomato plants in the affected rows, as well as in adjacent rows (2 rows on both sides). The absence of further infections was confirmed by testing approximately 1 200 tomato plants in pooled samples for PSTVd by RT-PCR and real-time RT-PCR.
The situation of Potato spindle tuber viroid in Belgium can be described as follows: Absent, detected in 2006 in one tomato glasshouse, eradicated.
Verhoeven JTJ, Jansen CCC, Roenhorst JW, Steyer S, Michelante D (2007) First report of Potato spindle tuber viroid in tomato in Belgium. Plant Disease 91(8), p 1055.