First outbreak of Potato spindle tuber viroid on ornamental Solanaceae in Slovenia
The NPPO of Slovenia recently informed the EPPO Secretariat of the first record of Potato spindle tuber viroid (Pospiviroid, PSTVd – EPPO A2 List) on its territory. After the detection of PSTVd in ornamental plants notified by the Dutch NPPO (see also EPPO RS 2006/142), a follow-up inspection was done at a Slovenian place of production in October 2006 and one plant of Brugmansia cordata (Solanaceae) was found positive. During a monitoring survey, 9 samples of Solanum jasminoides also tested positive in December 2006. An official survey was imposed in 2007, and as a result 29 samples of S. jasminoides and 1 sample of Solanum rantonnettii were found positive at different places of production. The identification of PSTVd was done by the officially approved virological laboratory of the Agricultural Institute of Slovenia. A two step RT-PCR test was used according to the EPPO Diagnostic protocol (EPPO Standard PM7/33(1)). In 2006, all PCR products were sequenced, but afterwards only one sample of S. rantonnettii and several randomly selected samples of S. jasminoides were sequenced. Sequence analyses confirmed the presence of PSTVd. The infection in Brugmansia cordata was also confirmed by the laboratory of the Dutch NPPO. Since in ornamental plants PSTVd infection is symptomless, all registered producers were inspected in spring 2007. Samples were taken from finished pot plants and their mother plants. Eradication measures were imposed: all infected lots and their mother plants were destroyed. Mother plants had been imported in different years: 2000, 2002, 2003 and 2006, and studies are being done to trace the origin of the PSTVd outbreak.
The status of Potato spindle tuber viroid in Slovenia is officially declared as follows: Present, only in protected cultivation where host plants are grown, under eradication.
NPPO of Slovenia, 2007-07.