A ProMED-mail post
<http://www.promedmail.org>
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International Society for Infectious Diseases <http://www.isid.org>
Date: October 2008
Source: European Plant Protection Organisation (EPPO) Reporting
Service 10/2008/206 [edited] <http://archives.eppo.org/EPPOReporting/2008/Rse-0810.pdf>
An emerging virus, _Colombian datura virus_ (CDV; genus
_Potyvirus_), might present a risk to solanaceous crops.
CDV was 1st isolated and described in 1968 from _Datura_ species
imported from Colombia to the USA. It is transmitted by
aphids (including _Myzus persicae_) in a non-persistent manner,
as well as by mechanical inoculation and grafting. Symptoms of
CDV can include reduction in leaf size, vein banding, chlorotic
flecking followed by mottling, reduction of plant size and
occasionally flower discolouration. CDV infections may remain
symptomless, but when plants are stressed, leaf mottling and
mosaic patterns may appear.
In 1996, CDV was reported to occur in Germany and the
Netherlands on ornamentals (_Brugmansia_, _Juanulloa_,
_Petunia_) and tomato (_Solanum lycopersicum_). In a glasshouse
in the Netherlands, approximately 300 tomato plants showed
growth reduction, foliar mosaic and fruit discolouration.
Observations suggested these tomato plants had probably been
contaminated by aphids which had acquired the virus from a large
CDV-infected _Brugmansia_ plant in the same glasshouse. In 2004,
CDV infections were detected in tobacco
(_Nicotiana tabacum_) in Hungary, Germany and Poland. Affected
plants showed conspicuous chlorotic and necrotic leaf symptoms.
In Hungary, recent studies have showed that CDV caused severe
diseases in experimental fields of Cape gooseberry (_Physalis
peruviana_) and was found naturally infecting pepino (_Solanum
muricatum_) plants. Inoculation studies have shown that potato
(_Solanum tuberosum_) could be a potential host of CDV, but no
natural infections have been reported.
In the USA, CDV was detected in 2003 and 2004 in symptomatic
ornamentals in several states (_Spiranthes_ orchids,
_Brugmansia_). Preliminary studies suggest that CDV is more
widespread than originally thought. In Australia, CDV was 1st
detected in 2007 on _Brugmansia_ in New South Wales, and
subsequently in Victoria. CDV
isolates from Japan (tomato, 2004), USA (_Brugmansia_, 2007) and
Canada (2008) have been deposited in the GenBank database.
However, in the absence of any other supporting data, it is
difficult to assess the situation of the disease in these areas.
Although much data is lacking on the host range, geographical
distribution and more particularly on the economic impact of the
disease in solanaceous crops, it seems that CDV is emerging in
different parts of the world. More attention should probably be
paid to the health status of ornamental _Solanaceae_, as these
may act as inoculum sources for economically important crops.
[Byline: Personal communication, Dr P. Salamon, Vegetable Crops
Research Institute, Kecskemet, Hungary, 2008]
--
Communicated by:
ProMED-mail <promed@promedmail.org>
[With the exception of _Spiranthes_, all species mentioned above
belong to genera within the dicot family of the _Solanacea_,
which also contains important crop species. _Gomphrena_ (dicot
family of _Amaranthaceae_) has also been found susceptible to
CDV inoculation. _Spiranthes_, however, belongs to the quite
unrelated monocot family of the _Orchidaceae_, and monocots have
not otherwise been reported as hosts of CDV. Thus, this reported
detection may need further confirmation, but if it can be
verified, it may indicate a wide host range of CDV and a
potential threat to a wider range of crops.
The genus _Potyvirus_ is the largest of the plant virus genera
and contains many species that seriously affect a wide range of
crop plants. Disease management of aphid-transmitted viruses is
often difficult because the vectors are ubiquitous and difficult
to control. If resistant crop cultivars are available, these are
usually
the most promising approach. Furthermore, some potyviruses can
be seed transmitted, and it is not known yet whether CDV belongs
to this group.
Pictures
_Brugmansia_ (Angel's Trumpet):
<http://www.freewebs.com/froglver/Brugmansias/Dr%20Suess%20Brugmansia.jpg>
and
<http://www.blueworldgardener.co.uk/blog/uploaded_images/asg-brugmansia-1-725992.JPG>
_Datura_ (Thorn Apple):
<http://www.ubcbotanicalgarden.org/potd/datura_inoxia2.jpg>
and
<http://www.missouriplants.com/Bluealt/Datura_stramonium_flower2.jpg>
Cape gooseberry:
<http://www.tropicalfruitandveg.co.uk/images/physalis.jpg>
_Potyvirus_ particles:
<http://www.ncbi.nlm.nih.gov/ICTVdb/WIntkey/Images/a1.gif>
Links
CDV factsheet (with pictures):
Information on CDV:
<http://www.dpi.nsw.gov.au/__data/assets/pdf_file/0017/211319/Flower-News-issue-9-Summer-2008.pdf>,
<http://www.pestalert.org/viewNewsAlert.cfm?naid=21>
and
<http://www.ulmer.de/Artikel.dll/nb_0105_strumpf_MjYyODA5.PDF?UID=8A2DF6CAE86C77538B6B0F8D717E5D4F997BCA5B808BD0>
(in German)
CDV taxonomy and description:
<http://www.ncbi.nlm.nih.gov/ICTVdb/ICTVdB/00.057.0.01.019.htm>
Taxonomy and description of genus _Potyvirus_:
<http://www.ncbi.nlm.nih.gov/ICTVdb/ICTVdB/00.057.0.01.htm>
List of genera of _Solanaceae_:
<http://www.mobot.org/MOBOT/research/APweb/genera/solanaceaegen.html>
and
<http://www.ars-grin.gov/cgi-bin/npgs/html/family.pl?1043>
EPPO plant disease monitoring:
<http://www.eppo.org/QUARANTINE/quarantine.htm>
- Mod.DHA]
