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: September 2015
Source: European Plant Protection Organisation (EPPO) Reporting Service 9/2015/165 [edited] <http://archives.eppo.int/EPPOReporting/2015/Rse-1509.pdf>
1st report of '_Candidatus_ Liberibacter solanacearum' on carrots in Germany
In September 2014, symptoms resembling those of '_Candidatus_ Liberibacter solanacearum' (the potato haplotypes are listed in the EPPO A1 List) were observed in commercial carrot (_Daucus carota_) fields in Niedersachsen [Lower Saxony], Germany. These fields were also infested by the carrot psyllid _Trioza apicalis_, and the infection rate was about 50 per cent symptomatic plants/field.
Symptoms included leaf curling, yellow and purple discoloration of leaves, stunted growth of shoots and roots, and proliferation of secondary roots.
Symptomatic carrot and psyllid samples were collected from 3 fields.
Asymptomatic carrots from an experimental field [were] used as negative controls. Laboratory analysis (PCR, sequencing) confirmed the presence of '_Ca._ L. solanacearum' in 12 (out of 26) symptomatic plants and in 10 (out of 42) psyllid samples.
This is the 1st time that '_Ca._ L. solanacearum' is reported from Germany.
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Communicated by: ProMED-mail <promed@promedmail.org>
[Only a few members of _Candidatus_ Liberibacter have been characterised so far, including the pathogens causing citrus greening (huanglongbing, HLB; for more information see previous ProMED-mail posts in the archives). HLB, one of the most damaging diseases of citrus, is limited to these crops due to the host specificity of its vector, the citrus psyllid.
A new liberibacter species was found to be associated with zebra chip
(ZC) and psyllid yellows (PY) diseases of potato, as well as a new yellowing disease of tomato and capsicum crops in New Zealand. The new pathogen was given the preliminary name of _Ca._ Liberibacter solanacearum (Lso; synonym _Ca._ L. psyllaurous). Lso has since also been associated with yellowing diseases of other solanaceous crops (physalis, tomatillo, aubergine [eggplant], tamarillo, tobacco) and some crops in the family Apiaceae (carrot, celery). Main vectors of Lso are the potato psyllid (_Bactericera cockerelli_) in solanaceous host and the carrot psyllid (_Trioza apicalis_) in Apiaceae. These vectors have a much wider host range than the HLB vector and additional vector species are also being identified, further extending its potential host range and economic impact.
Currently the Lso species is divided into 4 haplotypes: A & B affecting Solanaceae, C & D affecting Apiaceae. Both groups of haplotypes have been reported from the Americas and New Zealand.
Carrot haplotypes have been reported previously from several other European countries (ProMED-mail post 20120713.1199961) and northern Africa (ProMED-mail post 20141121.2978030), but potato haplotypes are still considered absent from the European/Mediterranean region.
Maps
Germany:
<http://www.lib.utexas.edu/maps/europe/germany.jpg> (with states) and <http://healthmap.org/promed/p/2856>
Europe, overview:
<http://www.edinphoto.org.uk/0_MAPS/0_map_europe_political_2001_enlarged.jpg>
Pictures
Lso affected carrot (compared with healthy):
<https://gd.eppo.int/media/data/taxon/L/LIBEPS/pics/1024x0/1939.jpg>
Zebra chip of potato:
<http://www.forestryimages.org/images/3072x2048/1490010.jpg> (plant) <http://www.dnature.co.nz/assets/Uploads/Liberibacter/Liberibacter.jpg>
(tuber) and
<http://www.digitaljournal.com/img/4/2/9/0/i/4/1/7/o/8ab1aa702fece1872973ac17aec85b6f.jpg>
(processed tuber, compared with healthy) Lso symptoms on other solanaceous hosts:
<http://www.dnature.co.nz/assets/Uploads/Liberibacter/_resampled/resizedimage300310-Libcapsicum.jpg>
(capsicum),
<http://www.biosecurity.govt.nz/files/images/blo-tomato-03.jpg>
(tomato) and
<http://nwdistrict.ifas.ufl.edu/phag/files/2014/10/Fig-7-PY-Dufault.jpg>
(tomato fruit)
Lso, microscopy:
<http://bacmap.wishartlab.com/system/images/1223/medium/Candidatus_Liberibacter.jpg?1319706599>
Carrot psyllid:
<http://www.biology.lu.se/sites/biology.lu.se/files/styles/lu_page_image/public/psyllid320.jpg?itok=QGU4AwFj>
Links
Information on _Ca._ Liberibacter solanacearum:
<http://www.eppo.int/QUARANTINE/Alert_List/bacteria/Liberibacter_psyllaurous.htm>,
<http://onlinelibrary.wiley.com/doi/10.1111/epp.12043/pdf>,
<http://www.cabi.org/isc/datasheet/109434>,
<http://www.rhizobia.co.nz/downloads/Weir_CS23.pdf>, and via <http://archives.eppo.org/EPPOReporting/2012/Rse-1209.pdf>
Lso haplotypes:
<http://link.springer.com/article/10.1007/s10658-012-0121-3/fulltext.html>
and
<http://www.appsnet.org/publications/Potato_Diseases_Workshop/9.%20Poliakoff_C%20liberabacter%20solanacearum%20in%20carrot%20France.pdf>
Information on carrot psyllid vector:
<http://www.ncbi.nlm.nih.gov/pubmed/20857712> and <http://onlinelibrary.wiley.com/doi/10.1111/j.1744-7348.2012.00551.x/full>
Information on potato zebra chip disease:
<http://www.digitaljournal.com/article/257488> and <http://link.springer.com/article/10.1007/s10658-010-9702-1/fulltext.html>
_Ca._ L. solanacearum taxonomy:
<http://www.uniprot.org/taxonomy/556287>
Genus _Ca._ Liberibacter taxonomy and species list:
<http://beta.uniprot.org/taxonomy/34019>
EPPO A1 quarantine list:
<http://www.eppo.int/QUARANTINE/listA1.htm>
- Mod.DHA]
[See Also:
Liberibacter, solanaceous crops - Norfolk Island: 1st rep.
20150417.3303297
2014
----
Liberibacter, carrot - Africa: 1st rep, Morocco 20141121.2978030
2012
----
Liberibacter, vegetable crops - multicountry 20120713.1199961
2011
----
Zebra chip, potato - USA, New Zealand: updates 20110915.2812
2009
----
Liberibacter, solanaceous crops - multicountry 20090515.1819
2008
----
Novel pathogens, tomato, potato - USA 20080820.2593 Liberibacter, solanaceous crops - New Zealand, USA 20080725.2269 Liberibacter, tomato & capsicum - New Zealand: new pathogen
20080604.1781
2007
----
Zebra chip disease, potato - USA: research 20070530.1751]
Topics
Species
