A
ProMED-mail post
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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: June 13, 2008
Source:
North American Plant Protection Organization (NAPPO),
Phytosanitary Alert System [edited] <http://www.pestalert.org/viewNewsAlert.cfm?naid=59>
Tomato zonate spot virus (TZSV; proposed): a significant new
tospovirus of vegetable crops in Yunnan, China
In 2005, a devastating virus-like disease was observed on
field-grown tomatoes and chili peppers in Yunnan Province,
China. Diseased plants exhibited concentric zoned ringspots on
ripe fruits and necrotic lesions on leaves. Based on particle
morphology, host range, and serological properties, the causal
agent of this disease was determined to be a new species of
_Tospovirus_, tentatively named Tomato zonate spot virus (TZSV).
Symptoms of TZSV infection varied widely, depending on the
cultivar, stage of plant growth at the time of infection, and
environmental conditions. Plants infected in the early stages of
growth were severely stunted and failed to produce fruit. If
older plants were infected, young fruit were often malformed and
showed slightly sunken patches or rings of small necrotic
flecks, while on ripe fruit the concentric ringspots were more
conspicuous. Internal necrotic lesions, which developed on the
stem of infected plants, sometimes resulted in plant death.
Mechanical inoculation of experimental test plants revealed that
members of the _Solanaceae_ plant family were more susceptible
to TZSV infection than plants of other families. During field
surveys, leaves of carnation (_Dianthus caryophyllus_), taro
(_Colocasia esculenta_), curly dock (_Rumex crispus_) and
spinach (_Spinacia oleracea_) were also found displaying
TZSV-like symptoms, and when tested, reacted positively to
TZSV-specific
antiserum. These results suggest that TZSV has a wide host range
that includes both agricultural crops and ornamental plant
species. Three thrips species (_Frankliniella occidentalis_,
_Thrips palmi_ and _T. tabaci_), potential vectors of TZSV, were
also found in the fields surveyed, however, confirmation of
disease transmission by these thrips is still under
investigation.
Vegetable crops like tomato and capsicum are hosts to dozens of
different viruses, many with diverse biological properties and
highly variable impacts. Keeping track of these viruses, their
hosts, distributions, and potential pathways, make phytosanitary
regulation of these types of organisms difficult. However, given
that TZSV is at this time only known from one part of China, its
exclusion from other vegetable production areas may be a
worthwhile objective.
Reference
---------
Jia-Hong Dong, et al. Characterization of Tomato zonate spot
virus, a new tospovirus in China. Archives of Virology 2008;
153(5): 855-64.
--
communicated by:
ProMED-mail
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[Tospoviruses are an extremely important group of plant viruses
capable of infecting a large range of crops and consequently
research on this virus group has increased dramatically in
recent years. As a result, many new tospoviruses are being found
and many more can be expected to exist.
The type member, _Tomato spotted wilt virus_ (TSWV), has one of
the broadest host ranges among plant viruses and is one of few
affecting both dicot and monocot hosts. It is regarded as one of
the most economically destructive plant pathogens and has had a
serious impact on many crop species worldwide causing up to 100
per cent yield loss in some instances. For more information on
TSWV, see links and previous posts listed below.
Tospoviruses are transmitted exclusively by species of thrips,
which are found worldwide. Transmission occurs in a circulative
propagative manner meaning that the virus multiplies in the
vector. Nymphs must emerge on an infected host plant to be able
to acquire the virus, which is then spread by the adult insects.
Thus, tospovirus epidemiology is complex. Disease management of
tospoviruses includes vector control, use of clean planting
material, control of weed hosts of virus and vectors,
phytosanitation, and use of resistant crop cultivars if
available.
Trying to limit the spread of plant pathogens by applying
phytosanitary measures, as suggested above for the new TZSV in
vegetables, should be general practice to protect all crops
worldwide. Even if a pathogen is known to exist in a certain
region, quarantine regulations are vital to prevent
re-introduction which may lead to the establishment of different
and potentially more damaging strains (as has been reported on a
number of occasions for different pathogens and locations).
Furthermore, eradication of plant pathogens, once they are
introduced to a new area, has been shown to be very rarely
successful in the past.
Maps
China:
<http://www.chinapage.com/map/map.html>
and
<http://healthmap.org/promed?v=36.5,103.9,4>
Yunnan province:
<http://www.maps-of-china.com/yunnan-s-ow.shtml>
Pictures
Electron micrograph of _Tospovirus_ particles (TSWV):
<http://www.rothamsted.bbsrc.ac.uk/ppi/links/pplinks/virusems/b6.jpeg>,
Symptoms of TSWV on different hosts:
<http://www.eppo.org/QUARANTINE/virus/Tomato_spotted_wilt_virus/TSWV00_images.htm>
and
<http://vegetablemdonline.ppath.cornell.edu/PhotoPages/Tomatoes/Tom_SpWilt/Tom_SpWiltPhotoList.htm>
Western flower thrips:
<http://www.insectimages.org/images/768x512/4387048.jpg>
_T. palmi_:
<http://www.insectimages.org/browse/detail.cfm?imgnum=5368115>
_T. tabaci_:
<http://www.insectimages.org/images/768x512/1327078.jpg>
Links
Information on tospoviruses:
<http://www.mcb.uct.ac.za/tutorial/emerging%20plant%20viruses.htm>
and
<http://www.apsnet.org/online/feature/tospovirus/>
_Tospovirus_ taxonomy and species list:
<http://phene.cpmc.columbia.edu/ICTVdB/11050000.htm>
Current list of recognised tospoviruses (August 2007):
<http://www.oznet.ksu.edu/tospovirus/tospo_list.htm>
_Tospovirus_ resource centre:
<http://www.oznet.ksu.edu/tospovirus/welcome.htm>
TSWV fact sheet:
<http://vegetablemdonline.ppath.cornell.edu/factsheets/Virus_SpottedWilt.htm>
TSWV taxonomy:
<http://phene.cpmc.columbia.edu/ICTVdB/11005003.htm>
Thrips information:
<http://www.cals.ncsu.edu/course/ent425/text18/plantvectors.html>
Description of western flower thrips:
<http://www.gladescropcare.com/wfthp.html>.
- Mod.DHA]
[see also in
the
archive:
Tospoviruses, lettuce - USA: (CA) 20080601.1758
Iris yellow spot virus, onion - Germany: 1st rep. (RP)
20080320.1072
Iris yellow spot virus, multicrop - UK, Canada: 1st reps
20080221.0698
Tomato spotted wilt virus, capsicum - Spain (Almeria)
20080123.0280
2007
---
Tomato viruses TSWV, TICV - Jordan: 1st reports 20071223.4123
Iris yellow spot virus, onion - South Africa: 1st rep
20070920.3129
Tomato spotted wilt virus, tomato - USA (CA) 20070608.1872
Groundnut ringspot tospovirus, peanut - Argentina (Cordoba): 1st
report
20070524.1670
2006
---
Iris yellow spot virus, onion - Peru: 1st report 20060225.0612
2005
---
Iris yellow spot virus, onion - Chile 20051128.3444
Iris yellow spot virus, onion - Spain: 1st report 20051121.3384
Tomato fruit yellow ring virus, new tospovirus - Iran
20050511.1292
Iris yellow spot, onion - India (Maharashtra): 1st rep.
20050507.1266
Iris yellow spot, onion - France (Reunion Island): 1st report
20050502.1219
Tomato spotted wilt, Sw5 resistance gene - Italy 20050329.0914
Impatiens necrotic spot, potato - USA (NY) 20050312.0735
Iris yellow spot, onion - USA (OR) 20050112.0110
2004
---
Tomato spotted wilt, Iris yellow spot, onion - USA (GA)
20041031.2938
Iris yellow spot virus, onion - USA (NM) 20040911.2529
Tomato spotted wilt, pepper - Spain 20040605.1519
Iris yellow spot virus, onion - USA (WA) 20040215.0492
2003
---
Tomato spotted wilt, tomato - USA (FL & GA) 20031009.2539
2002
---
Groundnut ringspot virus, soybean - South Africa 20021023.5622
Tomato spotted wilt, tomato - USA (MA): Correction 20020627.4618
Tomato spotted wilt, tomato - USA (Massachusetts) 20020626.4608
Tomato spotted wilt, tomato - USA (North Carolina) 20020622.4565
Tomato spotted wilt, tomato - (USA) Virginia 20020620.4545
Iris yellow spot virus, onion - USA (Colorado) 20020614.4495
Iris yellow spot virus, onion - USA (Colorado) 20020613.4489
Groundnut bud necrosis virus - Iran 20020518.4261
2001
---
Tomato spotted wilt tospovirus, soybean - Iran 20011229.3130
Tomato spotted wilt, peanut - Iran 20011220.3069
Tomato spotted wilt disease, tomato - Kenya 20011109.2778
Tomato viruses - Tunisia 20010926.2349
2000
---
Melon yellow spot virus - Japan: EPPO report 20001205.2117
Tomato spotted wilt tospovirus, crops - USA (Georgia)
20000617.0989
Impatiens necrotic spot tospovirus, peanuts - USA 20000530.0869
Tomato spotted wilt tospovirus - Europe 20000302.0286
Tospoviruses - Argentina 20000213.0197
Tospovirus, zucchini, courgette & cucumber - Brazil
20000129.0145
1999
---
Impatiens necrotic spot tospovirus - Israel 19991107.1993] |
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