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: Thu 11 Jun 2015
Source: Farmers Weekly [edited]
<http://www.fwi.co.uk/arable/cereals-2015-turnip-yellows-virus-hotspots-revealed-in-nationwide-oilseed-rape-survey.htm>
Oilseed rape crops have been struck by up to 92 per cent turnip yellows virus (TuYV) infection in parts of England this year [2015], a new nationwide survey has confirmed. The virus is spread by infected aphids.
The findings were described as "worrying" by John Walsh of Warwick University. "Levels of infection are much higher than they have been for the past few seasons, with crops in parts of Yorkshire as much as
92 per cent infected. Generally, these hotspots are where you would expect them, due to the large areas of oilseed rape being grown locally." Additionally, the survey showed some more surprising TuYV hotspots, such as a 74 per cent infection in Somerset.
Dr Walsh said the level of aphid activity in a season broadly correlates with the level of virus infection in oilseed rape crops.
"In years with high levels of infection, we found that even neonic[otinoid insecticides] weren't that effective against TuYV.
Plant resistance is now definitely the way forward."
[Byline: Oliver Hill]
--
Communicated by: ProMED-mail <promed@promedmail.org>
[Based on molecular evidence, European non-sugar beet infecting strains of _Beet western yellows virus_ (BWYV) have been reclassified as the separate species _Turnip yellows virus_ (TuYV) in the genus _Polerovirus_ (_Luteoviridae_). TuVY is considered an emerging threat to European oilseed rape production and possibly the most important viral disease of oilseed rape in the UK preventing crops from reaching their genetic yield potential. Losses of seed yields of close to 50 per cent have been reported (for example from Australia). In addition, yield and quality of oil from affected seeds is also reduced. TuYV has a wide host range including all brassica crops, lettuce and many weed species.
Symptoms may include reddening or purpling of leaf margins and interveinal discolouration resembling some physiological or nutritional problems and may, therefore, be difficult to identify.
They are usually not expressed before stem elongation and up to 6 months after infection. TuYV is transmitted by aphid vectors, with the peach aphid (_Myzus persicae_) considered the most important. Disease management may include insecticides for vector control in crops and as seed treatments, as well as cultural practices (for example, shelter belts or barrier plantings). Reliable information on susceptibility levels of current crop varieties is not available, but research is being carried out to identify potential genetic TuYV resistance traits to be used in breeding programmes.
Maps
UK (with counties):
<http://www.lib.utexas.edu/maps/europe/united_kingdom.gif>
Pictures
TuYV leaf symptoms on oilseed rape:
<http://www.blackthornarable.co.uk/uploads/images/d5%208145.JPG>,
<http://www.blackthornarable.co.uk/uploads/images/d5-8136.jpg>,
<http://www.bayercropscience.co.uk/media/261562/turnip-yellows-virus-osr-content.jpg>
and
<http://bmcontent.affino.com/AcuCustom/Sitename/DAM/010/TuYV-leaf_Main.jpg>
_M. persicae_ vector:
<http://www.blackthornarable.co.uk/uploads/images/T585-0034.jpg> (on rape leaf) and <http://bit.ly/NnIFsS>
Links
Additional news stories:
<http://www.allaboutfeed.net/Nutrition/General/2015/6/Oilseed-rape-suffering-from-turnip-yellows-virus-1771760W/>
and
<http://www.fginsight.com/news/high-levels-of-tuyv-detected-in-oilseed-rape-crop-survey-3042>
Information on TuYV in oilseed rape:
<http://www.oregin.info/stakeholders/meetings/shf07-Nov2009/Stevens_RRES_OREGIN_SHF7_Nov2009_TuYV.pdf>,
<http://academy.fwi.co.uk/Courses/Arable/Oilseed-rape-diseases/Turnip-yellows-virus>,
<http://archive.hgca.com/cms_publications.output/2/2/Publications/Final%20project%20reports/Turnip%20yellows%20virus%20%28syn%20Beet%20western%20yellows%20virus%29,%20an%20emerging%20threat%20to%20European%20oilseed%20rape%20production.mspx?fn=show&pubcon=4579>
and
<http://www.fwi.co.uk/articles/10/02/2014/143213/turnip-yellows-virus-resistant-osr-may-cut-losses.htm>
(resistance breeding)
BWYV disease information and description:
<http://www.ipm.ucdavis.edu/PMG/r441101411.html> (with host list) and <http://ictvdb.bio-mirror.cn/ICTVdB/00.039.0.02.003.htm>
Serological relationship between BWYV and TuYV:
<http://www.apsnet.org/publications/phytopathology/backissues/Documents/1972Articles/Phyto62n11_1274.PDF>
Virus taxonomy via:
<http://ictvonline.org/virusTaxonomy.asp?version=2012>
Information on _M. persicae_:
<http://entnemdept.ifas.ufl.edu/creatures/veg/aphid/green_peach_aphid.htm>
- Mod.DHA
A HealthMap/ProMED-mail map can be accessed at:
<http://healthmap.org/promed/p/40>.]
[See Also:
2014
----
Viral yellows, oilseed rape - Australia (02): (VI, NS)
20140718.2619590
Viral yellows, oilseed rape - Australia: (SA) 20140708.2594485
2011
----
Vegetable viruses - Australia: (WA, QL) 20110314.0817
2010
----
Turnip yellows virus, oilseed rape - UK: (England) 20100227.0653
2008
----
Beet mosaic virus, lettuce - China: new host, (Shandong)
20080312.0990
2007
----
Beet and cucurbit viruses, multiple hosts - China: 1st reports 20070516.1564]
Topics
Species
