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Date: June 9, 2008
Source: Flex News [edited]
<http://www.flex-news-food.com/pages/17002/Tomato/new-tomato-pathogen-found-finland.html>

New tomato pathogen found in Finland

The Finnish Food Safety Authority, Evira, has found a new tomato pathogen in Finland -- _Tomato apical stunt viroid_ (TASVd) -- on _Solanum jasminoides_ plants grown as summer flowers. If it spread to tomato the viroid could cause considerable crop losses. Evira warns tomato growers for the viroid's spreading with the ornamental plants of the _Solanaceae_ family. TASVd was found in a Finnish greenhouse on _S. jasminoides_ plants imported from Holland, which did not exhibit any symptoms. TASVd was found in a sample taken for a survey of _Potato spindle tuber viroid_ (PSTVd), but PSTVd has not been found in Finland. The contaminated consignments were destroyed.

Both PSTVd and TASVd can be totally harmless on many ornamental plants, but produce strong symptoms on tomatoes. Symptomless ornamental plants can be a reservoir for the spread of the viroids into tomato production. PSTVd and TASVd spread very easily with sap, for example during pruning or cutting.
TASVd in tomatoes causes bushiness, leaf deformation, and yellowing. The fruit of contaminated plants remain small, they are a pale red in colour, and the shelf life is significantly reduced. Destruction of the plants, disinfection of the growing area and tools, and the use of clean plant material are the only way to counter the viroids.

Evira advises tomato growers to keep in mind that totally symptom-free ornamental plants of the _Solanaceae_ family can be contaminated by TASVd.
An important preventative method in order to avoid contamination is to grow other _Solanaceae_ in areas separate from tomatoes.

TASVd has been found in tomato production in Israel, the Ivory Coast, Indonesia, Tunisia, and Senegal. It has also been found in Europe on ornamental plants but its distribution is not yet clearly known.

--
communicated by:
ProMED-mail
<promed@promedmail.org>

[_Tomato apical stunt viroid_ (TASVd; genus _Pospiviroid_) has been included on the EPPO (European Plant Protection Organisation) alert list.
Until now, very few data were available on its host range other than tomato. Symptoms in tomato are stunting, leaf distortion, reduced fruit size, and discolouration. Up to 100 per cent incidence with heavy yield losses has been reported. The viroid is transmitted by plant material, mechanical means, seed, and bumblebees.

The presence of this and other viroids in a number of symptomless reservoir hosts reported recently from several European countries (see previous ProMED-mail post no. 20080221.0707 and link below) must be considered a threat to crops in the region. It highlights the importance of systematic surveys and quarantine measures for these pathogens, even if there are no obvious problems with crops in the respective areas.

Maps
Finland:
<http://www.mapsofworld.com/finland/maps/map-finland.jpg>  and
<http://healthmap.org/promed?v=64.5,26.3,5>
Europe:
<http://www.greece-map.net/europe/europe-map.gif>
Pictures of TASVd symptoms on tomato:
<http://vegetablemdonline.ppath.cornell.edu/Images/Tomato/Tom_ApicalStnt/Viroid_02B.jpg> 

Links
Tomato apical stunt disease:
<http://www.eppo.org/QUARANTINE/Alert_List/viruses/TASVD0.htm>  and
<http://www.phytoparasitica.org/phyto/pdfs/2002/issue5.pub/ANTI.pdf>
TASVd in ornamentals in Germany and Belgium:
<http://apsjournals.apsnet.org/doi/abs/10.1094/PDIS-92-6-0973A>
Genus _Pospiviroid_ taxonomy and species list:
<http://www.ncbi.nlm.nih.gov/ICTVdb/ICTVdB/80.001.0.01.htm>
EPPO quarantine and alert lists via:
<http://www.eppo.org/QUARANTINE/quarantine.htm>.  - Mod.DHA]

[see also in the archive:
Pospiviroids - Europe: 1st reps, new hosts 20080221.0707
2006
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Tomato apical stunt viroid - Tunisia: 1st Report 20060403.1003
2003
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EPPO Alert List: new listings (06) 20030910.2273]

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