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[1] _Tomato chlorosis virus_ - Turkey: 1st report
[2] _Tomato chlorosis virus_ - France: Mayotte Island, 1st report

[1] _Tomato chlorosis virus_ - Turkey: 1st report
Date: August 2007
Source: British Society for Plant Pathology, New Disease Reports
(NDR) vol. 16 [edited]
<http://www.bspp.org.uk/ndr/jan2008/2007-79.asp>

Report of _Tomato chlorosis virus_ in Turkey

A tomato (_Lycopersicon esculentum_) plant showing severe interveinal leaf chlorosis with brown necrotic flecks was supplied by a commercial tomato greenhouse located in Fethiye, Mugla, Southwestern Turkey. The symptoms were similar to those described for infection of tomato by _Tomato infectious chlorosis virus_ (TICV) and _Tomato chlorosis virus_ (ToCV) criniviruses. During a limited field survey, similar symptoms and the presence of whiteflies (_Bemisia tabaci_ Genn. and _Trialeurodes vaporariorum_ Westw.) as potential virus vectors were observed on tomato plants in various greenhouses in the same region, suggesting possible TCIV or ToCV infection. Leaf samples were taken from symptomatic and non-symptomatic tomato plants from 4 different greenhouses in the same area.

Total RNA from 8 symptomatic and one non-symptomatic tomato plants were tested for the presence of TICV and ToCV by a previously reported method using RT-PCR [Reverse-Transcription Polymerase Chain
Reaction) for the detection of criniviruses. This was followed by virus-specific PCR. A negative result [no PCR product] for TICV was observed in the non-symptomatic or symptomatic plants. Conversely, a positive result [a 463 basepair DNA PCR product] was obtained from all symptomatic tomato samples. No PCR product was observed in the sample from the non-symptomatic plant. These results suggested that the symptomatic plants were infected with ToCV.

The nucleotide sequence of the PCR product showed 99 percent identity with the corresponding gene of ToCV isolates from Florida, USA, confirming the diagnosis of ToCV. To our knowledge, this is the 1st report of ToCV in Turkey.

[Byline: Bayram Cevik and Gozde Erkis]

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

[2] _Tomato chlorosis virus_ - France: Mayotte Island, 1st report
Date: August 2007
Source: British Society for Plant Pathology, New Disease Reports
(NDR) vol. 16 [edited]
<http://www.bspp.org.uk/ndr/jan2008/2007-69.asp>

Tomato chlorosis virus: A first report in Mayotte Island

In November 2005, a survey of symptomatic greenhouse tomato (_Lycopersicon esculentum_) plants was conducted on Mayotte Island, an island located in the northern part of the Mozambique Channel.
Yellow leaf symptoms were observed on the lower and middle leaves of tomato plants from the northern (Koungou), western (Chiconi and Combani) and southern (Chirongui) regions. A flame-like pattern of the discoloured leaves and the similarity of the symptoms to the first description of _Tomato chlorosis virus_ (ToCV, _Crinivirus_) on tomato in 2004 in Reunion Island suggested the possible involvement of the same virus in Mayotte Island.

Symptomatic leaf samples were collected from tomato plants from one greenhouse from each of the 4 affected regions. Total RNA was analysed for the detection of a potential crinivirus by RT-PCR. PCR products of the expected size (419 basepairs) were observed for all samples. A total of 3 PCR products were sequenced and found to have 99 percent nucleotide identity with each other. Their highest nucleotide identities were between 98 and 99 percent with corresponding sequences of ToCV isolates from France, Spain, Italy and Reunion. To our knowledge, this is the 1st report of ToCV from Mayotte Island.

[Byline: D. Masse, et al.]

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

[ToCV (genus _Crinivirus_, family _Closteroviridae) has been reported from Europe, Taiwan, Japan, South Africa, Reunion Island and a number of locations in the Americas. It has been placed on the alert list of the European Plant Protection Organisation (EPPO). Besides tomato, it has also been reported to affect capsicum and some solanaceous weeds which may serve as pathogen reservoirs, as well as some ornamental and weed species in other families.

Tomato plants infected with ToCV show an irregular chlorotic mottle that develops first on lower leaves and gradually advances toward the growing point. Interveinal yellow areas on leaves also develop red and brown necrotic flecks. No obvious symptoms develop on fruit and flowers, but fruit size and numbers are reduced due to a loss of photosynthetic area. Significant yield losses occur as a result.
Other symptoms include rolling of lower leaves and thickened crispy leaves, while the upper leaf canopy appears normal. Symptoms take 3-5 weeks to develop and severity varies with host cultivars. Symptoms may be confused with nutritional problems and are also similar to those of _Tomato infectious chlorosis virus_ (TICV), a related species in the genus _Crinivirus_.

ToCV is transmitted by whitefly vectors (_Bemisia tabaci_, _Trialeurodes vaporariorum_ and _T. abutiloneus_) in a semi-persistent manner. Insects remain infectious for 2-3 days, and viruliferous whiteflies may be spread on plant material or by air currents. Like most members of the _Closteroviridae_, ToCV is unlikely to be seedborne. Outbreaks are usually associated with high vector populations and have been described as epidemics. Incidences of up to 70 percent symptomatic plants have been reported. Disease management of whitefly transmitted viruses is difficult and includes vector control, removal of reservoirs of both virus and vectors, use of crop varieties with increased pathogen tolerance, and clean planting material.

Maps
Turkey:
<http://media.maps.com/magellan/Images/TURKEY-W1.gif> and <http://healthmap.org/promed?v=39.1,35.2,5>
Mugla province:
<http://www.mapzones.com/maps/turkey/mugla.php>
Mayotte Island:
<http://upload.wikimedia.org/wikipedia/commons/5/5f/Mayotte-CIA_WFB_Map.png>
Mayotte location within Comoros group:
<http://worldatlas.com/webimage/countrys/africa/lgcolor/kmcolor.htm>
Comoros location within Africa:
<http://worldatlas.com/webimage/countrys/africa/maps/africa.htm>
Worldwide distribution of ToCV (Sept. 2006):
<http://www.eppo.org/QUARANTINE/virus/Tomato_chlorosis_virus/TOCV00_map.htm>

Pictures
ToCV leaf symptoms:
<http://www.apsnet.org/online/feature/whitefly/view.asp?ID=411>
_B. tabaci_ picture gallery:
<http://www.eppo.org/QUARANTINE/insects/Bemisia_tabaci/BEMITA_images.htm>
_T. vaporariorum_:
<http://www.apsnet.org/online/feature/whitefly/view.asp?ID=404>

Links
ToCV information:
<http://www.eppo.org/QUARANTINE/Alert_List/deleted%20files/virus/Tomato_infectious_chlorosis_crinivirus.doc>
and
<http://www.prpv.org/index.php/fr/layout/set/print/protection_des_cultures/
fiches_maladies_et_ravageurs_par_culture/cultures_maraicheres/les_crinivirus_de_la_tomate_tocv_ticv>
(in French)
Information on whitefly transmitted viruses, including ToCV:
<http://www.apsnet.org/online/feature/whitefly/>
Information on whitefly vectors:
<http://www.ipm.ucdavis.edu/PMG/r783301211.html>
Genus _Crinivirus_ taxonomy and species list:
<http://www.ncbi.nlm.nih.gov/ICTVdb/ICTVdB/00.017.0.02.htm>
EPPO quarantine alert list:
<http://www.eppo.org/QUARANTINE/listA2.htm>
- Mod.DHA]

[see also in the archive:
2005
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Tomato chlorosis virus, tomato - Cyprus: 1st report 20051228.3699 Tomato chlorosis, tomato - France (Reunion Island): 1st report 20050605.1566 Tomato criniviruses - France: 1st report 20051122.3397
2004
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Tomato chlorosis virus, tomato - Israel:1st report 20041019.2834
2002
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Tomato chlorosis virus - Morocco 20020731.4904 Tomato criniviruses, detection - Greece 20021130.5939
2001
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Tomato chlorosis crinivirus disease - Puerto Rico 20010324.0588 Tomato chlorosis crinivirus - Puerto Rico 20010515.0942 2000
----
Tomato chlorosis crinivirus - Portugal: EPPO report 20001129.2080
1999
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Tomato chlorosis virus, new - USA 19990125.0120
1997
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Tomato chlorosis virus: Diagnosis 19970319.0582]

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