A ProMED-mail post <http://www.promedmail.org>
ProMED-mail is a program of the International Society for Infectious Diseases <http://www.isid.org>
Date: November 2016
Source: New Disease Reports [edited]
<https://www.ndrs.org.uk/article.php?id=034023>
[Ref: A Manglli et al (2016): First report of _Cucurbit yellow stunting disorder virus_ [CYSDV] infecting cucurbits in Italy. New Disease Reports 34, 23; DOI: 10.5197/j.2044-0588.2016.034.023]
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In June 2016, a survey was conducted in Sardinia to study the variability of cucurbit viral populations in melon and zucchini. Leaf yellowing was widely observed on field-grown melon plants, often associated with thickening, brittleness or cracking and early browning of the lower leaves.
A total of 70 samples from 8 farms (approx. 250 000 sq m) were collected from melon and zucchini plants showing virus-like symptoms.
25 melon and 2 zucchini [with] yellowing symptoms were tested for the presence of CYSDV by RT-PCR using the complete coat protein (CP) gene.
A product of the expected size (ca. 770 bp) was amplified from 4 melon and 1 zucchini collected in the province of Cagliari. The sequences from the 5 samples [were identical with each other], [with] highest similarity (99 per cent) to sequences from USA and Spain. Phylogenetic analysis showed that the Italian isolate clustered with isolates from the Mediterranean and the Americas within the "Western" group, which is phylogenetically distant from the "Eastern" group [that] includes isolates from Iran, Saudi Arabia, and Sudan.
Since its 1st identification in 1996, CYSDV has been reported in different Mediterranean countries but has not been found previously in Italy. The results suggest a low incidence of CYSDV. For this reason, we presume a recent introduction of the virus and further investigation in Sardinia and other Italian regions is needed.
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Communicated by: ProMED-mail <promed@promedmail.org>
[_Cucurbit yellow stunting disorder virus_ (CYSDV; genus _Crinivirus_) is thought to originate from the Middle East and has been reported from only few locations outside that region. Both the virus and its insect vector have been included on the A2 quarantine list of the European Plant Protection Organisation (EPPO). CYSDV affects mostly cucurbits such as melons, cucumber, and pumpkins. Symptoms may include leaf mottling and severe yellowing, as well as stunting of plants or leaf distortion on some of the hosts. Plant vigour is reduced due to loss of photosynthetic area, which may lead to significant yield losses. Symptoms may be confused with nutritional problems or those of some other cucurbit viruses.
CYSDV is transmitted by a number of whitefly vectors, including _Bemisia tabaci_. Whiteflies are a serious pest in themselves and have also been reported to transmit over 100 virus species. Outbreaks of whitefly transmitted viruses are usually associated with high vector populations. Multiple infections with viruses sharing the vectors are not unusual and may result in symbiotic enhancement of symptoms (synergism) of the co-infecting viruses.
Control of whitefly transmitted viruses is particularly difficult in open field crops due to the widespread presence and wide host range of whiteflies. Disease management 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
Italy:
<http://www.lonelyplanet.com/maps/europe/italy/map_of_italy.jpg> and <http://healthmap.org/promed/p/13544>
Italy, provinces and regions:
<http://www.lib.utexas.edu/maps/europe/italy_div96.jpg>
Europe, overview:
<http://www.edinphoto.org.uk/0_MAPS/0_map_europe_political_2001_enlarged.jpg>
Pictures
Cucurbit yellow stunting disease:
<https://bugwoodcloud.org/images/768x512/5125003.jpg> and <https://images.sciencedaily.com/2011/03/110309112904_1_900x600.jpg>
CYSDV affected melon fields:
<http://cals.arizona.edu/crop/vegetables/advisories/images/CYSDV_in_Melons.jpg>
and
<http://ucce.ucdavis.edu/files/repository/calag/img6604p125.jpg>
(resistant vs. susceptible cultivars)
Whiteflies on cucurbit leaf:
<http://files.growingproduce.com/growingproduce/wp-content/uploads/2016/05/whiteflies.jpg>
Links
Information on CYSDV and diseases:
<https://www.eppo.int/QUARANTINE/data_sheets/virus/DS_cucurbit_yellow_stunting.pdf>,
<http://www.cabi.org/isc/datasheet/17070> (with distribution maps), <http://www.growingproduce.com/crop-protection/disease-control/cucurbit-yellow-stunting-disorder-virus-cases-flaring-in-south-florida/>,
and
<https://www.apsnet.org/publications/phytopathology/backissues/Documents/1996Articles/Phyto86n12_1370.pdf>
CYSDV taxonomy via:
<http://ictvonline.org/virusTaxonomy.asp?version=2015>
EPPO A2 quarantine list:
<https://www.eppo.int/QUARANTINE/listA2.htm>
Information on whiteflies:
<https://gd.eppo.int/taxon/BEMITA> (with pictures), <http://www.issg.org/database/species/ecology.asp?fr=1&si=106>, and via <http://solutionsforyourlife.ufl.edu/hot_topics/agriculture/whiteflies.html>
- Mod.DHA]
[See Also:
2015
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Vegetable viruses - Spain: (AN) alert
http://promedmail.org/post/20151204.3839034
2007
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Cucurbit virus, CYSDV, melon - USA (AZ): Attempts of control
http://promedmail.org/post/20070425.1345
2006
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Cucurbit viruses CYSDV, CVYV - Cyprus: 1st reports
http://promedmail.org/post/20060320.0868
2003
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Cucurbit yellow stunting disorder - France
http://promedmail.org/post/20030524.1276
2002
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Tomato criniviruses, detection - Greece
http://promedmail.org/post/20021130.5939
2001
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Cucurbit yellow stunting dis. crinivirus - Portugal
http://promedmail.org/post/20010529.1040
and additional items on criniviruses in the archives]
Topics
Species
