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: Fri 17 Aug 2018
Source: New Disease Reports [edited]
[Ref: G Pasev et al (2018): First report of _Peanut stunt virus_ on beans in Bulgaria. New Disease Reports 38, 9; DOI:10.5197/j.2044-0588.2018.038.009]
Common bean (_Phaseolus vulgaris_) in Bulgaria [was] grown on 708 ha [about 1750 acres] in 2016. During the summer of 2013, leaf samples
(n=76) with virus-like symptoms were collected from bean plants in fields and private gardens. Disease incidence varied from 10 to 50 per cent. Symptoms consisted of green or yellow mosaic, blisters, and leaf distortion. In some locations the disease was associated with severe stunting.
DAS/TAS-ELISA tests revealed the presence of _Bean common mosaic virus_ (BCMV), _Cucumber mosaic virus_ (CMV), _Bean yellow mosaic virus_ (BYMV), and _Clover yellow vein virus_ (ClYVV) in the majority of the samples. However, 3 samples were positive for _Peanut stunt virus_ (PSV) and were traced to fields in which stunting symptoms were prevalent.
Electron microscopy revealed isometric particles approximately 28 nm in diameter. RT-PCR of bean extracts was performed using specific primers [and] amplicons of the expected size (651 bp) were obtained from the coat protein region for all 3 PSV isolates. Sequencing confirmed the identification of PSV. Phylogenetic analysis of all PSV isolates currently published in the NCBI database placed all 3 Bulgarian isolates in the Western subgroup (II), typified by the American PSV-W isolate.
PSV is known to cause severe infections on legumes worldwide. As a non-persistently transmitted aphid-borne cucumovirus, it might spread to other legumes including forage crops in Bulgaria. Monitoring infection of natural hosts would provide additional information about the epidemiology of the virus in Eastern Europe. To our knowledge this is the first report of PSV in the country and the second report of the occurrence of the Western strain of PSV in Europe.
Communicated by: ProMED-mail <firstname.lastname@example.org>
[_Peanut stunt virus_ (PSV; genus _Cucumovirus_) has been reported to infect legumes (including bean), as well as some other hosts including solanaceous and cucurbit species. It is spreading in parts of Europe, eastern Asia, northern Africa and North America. An Eastern and a Western group of strains have been designated according to different symptoms caused in bean and pea indicator varieties. Some sequence variations of satellite RNAs associated with PSV have been found to be able to modulate the symptoms induced in the host.
PSV is transmitted by several aphid species (including some _Aphis_ and _Myzus_ spp.). The aphids can acquire the virus in seconds. PSV does not accumulate in the vector and insects remain infectious for only a short period of time (non-persistent mode of transmission).
Seed transmission of PSV has been reported, for example at a low rate in peanut. The virus can also be spread with infected plant material and by mechanical means. Disease management is difficult, since aphid vectors and virus reservoirs are widespread. Use of certified virus free planting material is essential. Control of weeds surrounding cropped fields may also be helpful.
<http://bulgaria-map.info/maps/Bulgaria_Cities_Map.gif> and <http://healthmap.org/promed/p/81>
PSV symptoms on peanut:
<https://bit.ly/2oi2Mn0> (Florida Department of Agriculture and Consumer Services), <https://bugwoodcloud.org/images/768x512/5265067.jpg>,
<https://bit.ly/2MUCKUO> (Florida Department of Agriculture and Consumer Services) (affected field) PSV on bean:
<https://bit.ly/2ogUbB1> (Bean IPM)
PSV on clover:
PSV photo gallery:
Aphids (_Myzus persicae_):
<http://bit.ly/NnIFsS> (Alberta Agriculture and Forestry)
Information on PSV:
Information on genus _Cucumovirus_:
<http://www.dpvweb.net/notes/showgenus.php?genus=Cucumovirus>, and via <https://talk.ictvonline.org/ictv-reports/ictv_9th_report/positive-sense-rna-viruses-2011/w/posrna_viruses/251/bromoviridae>
Virus taxonomy via:
Information on aphids:
<https://www.britannica.com/animal/aphid>, and via <https://projects.ncsu.edu/cals/course/ent425/text18/plantvectors.html>
(as plant virus vectors)
Peanut stunt cucumovirus - USA (FL & GA)
and additional items on cucumoviruses in the archives]