A
ProMED-mail post
ProMED-mail is a program of the
International Society for Infectious Diseases
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: May 2008
Source: The American Phytopathological Society, Plant Disease
2008; 92(5), 836 [edited] <http://apsjournals.apsnet.org/doi/abs/10.1094/PDIS-92-5-0836C>
[Ref: Y Martinez-Zubiaur et al: First report of _Tomato
chlorosis virus_ infecting tomato in single and mixed infections
with _Tomato yellow leaf curl virus_ in Cuba.
Plant Dis 2008; 92(5), 836; DOI: 10.1094/PDIS-92-5-0836C]
Whitefly-transmitted viruses have caused severe losses in tomato
crops in Cuba. In 2006 and 2007, tomato greenhouses across
eastern Cuba exhibited high levels of _Bemisia tabaci_ (B
biotype) infestation. Some plants showed interveinal chlorosis
and a severe yellow mosaic, combined with leaf brittleness.
These symptoms were different from those induced by _Tomato
yellow leaf curl virus_ (TYLCV-IL(CU)).
Only 12 of 31 symptomatic samples resulted in positive PCR
[polymerase chain reaction] assays with TYLCV-specific primers.
A reverse transcription (RT)-PCR analysis for _Tomato chlorosis
virus_ (ToCV) with generic and specific primers was also carried
out. Sequence analysis of the cloned RT-PCR products
['amplicons'] (463 basepairs) confirmed the presence of ToCV in
Cuba. The fragment had 97 to 98 percent identity with isolates
from Spain, Florida (USA), and Reunion Island (France).
Cloned TYLCV and ToCV amplicons were used as probes to reanalyze
the selected 31 samples by a dot-blot hybridization assay [a
diagnostic method using labelled nucleotide sequences of the
viruses as 'probes' to detect the presence of similar sequences
in the samples - Mod.DHA] in search of mixed infections. The
assay showed 16 samples to be positive for ToCV, 4 for TYLCV, 8
for both, and 3 samples were negative. To our knowledge, this is
the 1st report of ToCV and TYLCV/ToCV mixed infections in Cuba.
--
Communicated by:
ProMED-mail
<promed@promedmail.org>
[ToCV (genus _Crinivirus_) has been reported from Europe and a
number of locations in other parts of the world. Besides tomato,
it can also affect capsicum and some solanaceous weeds, which
may serve as pathogen reservoirs, as well as some ornamental and
weed species in other families. Symptoms on tomato leaves
include irregular chlorotic mottle, interveinal yellowing,
necrotic flecks, and possible distortions. 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, but symptom severity varies with host
cultivars. Symptoms may be confused with nutritional problems
and are also similar to those of the related _Tomato infectious
chlorosis virus_ (TICV).
TYLCV (genus _Begomovirus_) originates from the Middle East and
is one of the most damaging viruses of tomato worldwide. It can
also affect a number of other solanaceous and leguminous hosts.
Infection of tomato causes plants to be stunted with small
chlorotic puckered leaves. Yield losses of up to 80 percent have
been reported, and
field cropping of tomatoes has been abandoned in some areas due
to TYLCV.
Both viruses are transmitted by the whitefly vector _Bemisia
tabaci_ (ToCV also by 2 other whitefly species), and outbreaks
are usually associated with high vector populations. 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. Both ToCV and TYLCV, as
well as their vector _B. tabaci_
are included on the quarantine alert list of the European Plant
Protection Organisation (EPPO). For more information on ToCV and
TYLCV see previous ProMED-mail posts listed below.
Whiteflies have been reported to transmit over 100 virus
species. _B. tabaci_ is believed to be a species complex with a
number of recognised biotypes varying in their distribution and
vector activities. Whiteflies are a common problem in glasshouse
grown crops, and multiple infections with viruses sharing this
vector are not unusual. Co-infecting viruses may interact with a
symbiotic enhancement of symptoms (synergism), as appears to be
the case here.
Maps
Cuba:
<http://www.caribnationtv.com/images/maps/cuba.jpg>
and
<http://healthmap.org/promed?v=21.6,-79,5>
Worldwide distribution of ToCV (September 2006):
<http://www.eppo.org/QUARANTINE/virus/Tomato_chlorosis_virus/TOCV00_map.htm>
TYLCV worldwide distribution (September 2006):
<http://www.eppo.org/QUARANTINE/virus/TYLC_virus/TYLCV00_map.htm>
Pictures
ToCV symptoms on tomato leaf:
<http://www.apsnet.org/online/feature/whitefly/view.asp?ID=411>
TYLCV symptoms on tomato plants:
<http://www2.dpi.qld.gov.au/images/13644.jpg>
and
<http://www.eppo.org/QUARANTINE/virus/TYLC_virus/TYLCV0_images.htm>
_B. tabaci_ picture gallery:
<http://www.eppo.org/QUARANTINE/insects/Bemisia_tabaci/BEMITA_images.htm>
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>
TYLCV information:
<http://www.defra.gov.uk/planth/pestpics/qic2004/QIC55.pdf>
and
<http://www2.dpi.qld.gov.au/health/4250.html>
EPPO data sheet TYLCV:
<http://www.eppo.org/QUARANTINE/virus/TYLC_virus/TYLCV0_ds.pdf>
TYLCV taxonomy:
<http://www.ncbi.nlm.nih.gov/ICTVdb/ICTVdB/00.029.0.03.043.htm>
B. tabaci_ taxonomy and biotypes:
<http://www.issg.org/database/species/ecology.asp?fr=1&si=106>
EPPO A2 list:
<http://www.eppo.org/QUARANTINE/listA2.htm>.
- Mod.DHA]
[see also in
the
archive:
2007
----
Tomato chlorosis virus - Turkey, Mayotte: 1st reports
20071215.4030
Yellow leaf curl begomoviruses - Netherlands, Taiwan: 1st
reports 20071128.3837
Tomato yellow leaf curl virus - USA (California, Texas)
20070413.1228
Yellow leaf curl, tomato - USA (AZ): 1st report 20070226.0694
2006
----
Begomovirus - multicountry: 1st reports 20060611.1625
Yellow leaf curl, tomato - Australia (QLD): 1st rep
20060330.0967
Yellow leaf curl, tomato - Multicountry: 1st reports
20060304.0702
2005
----
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
----
Tomato chlorosis virus, tomato - Israel: 1st report
20041019.2834
2002
----
Tomato chlorosis virus - Morocco 20020731.4904
Tomato criniviruses, detection - Greece 20021130.5939
2001
----
Tomato yellow leaf curl virus species 20010622.1187
Tomato chlorosis crinivirus - Puerto Rico 20010515.0942
Tomato chlorosis crinivirus disease - Puerto Rico 20010324.0588
2000
----
Tomato chlorosis crinivirus - Portugal: EPPO report
20001129.2080
1999
----
Tomato chlorosis virus, new - USA 19990125.0120
1998
----
Tomato yellow leaf curl begomovirus: spreading 19980528.1026
1997
----
Tomato yellow leaf curl virus and citrus canker - USA (Florida)
19970903.1869]
Tomato chlorosis virus: Diagnosis 19970319.0582] |
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