Strawberry latent ringspot 'nepovirus'

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Prepared by CABI and EPPO for the EU
under Contract 90/399003

Data Sheets on Quarantine Pests
Strawberry latent ringspot 'nepovirus'
IDENTITY
Name: Strawberry latent ringspot 'nepovirus'
Synonyms: Rhubarb virus 5
Taxonomic position: Viruses: Comoviridae: Possible Nepovirus
Common names: SLRSV (acronym) Strawberry latent ringspot (English)
EPPO computer code: SYLRSX
EU Annex designation: II/A2
HOSTS
SLRSV has a wide host range. It infects strawberries and raspberries, mostly without
symptoms but resulting in various degrees of mottle and decline in some cultivars. Other
fruit crop hosts are blackberries, black currants, red currants, cherries, grapes, plums,
peaches, Sambucus nigra. Furthermore it has been reported from asparagus, celery,
Gladiolus, Narcissus, rhubarb and roses. The virus occurs naturally in many species of wild
and cultivated plants and infects, often symptomlessly, a wide range of commonly used
herbaceous test plants. Schmelzer (1969) reported a wide host range among dicotyledonous
plants. In the EPPO region, strawberries and other fruit crops are the significant hosts.
GEOGRAPHICAL DISTRIBUTION
SLRSV is a European virus which has to a limited extent spread to other continents.
EPPO region: Belgium, Czech Republic, Finland, France, Germany, Hungary, Ireland,
Israel, Italy, Luxembourg, Netherlands, Poland, Portugal, Romania, Spain, Switzerland,
Turkey, UK, Yugoslavia. Probably throughout western Europe.
Asia: Israel, Turkey.
North America: Canada (Ontario, unconfirmed; report from Nova Scotia), USA (single
report from California).
Oceania: Australia (one report from South Australia), New Zealand.
EU: Present.
BIOLOGY
As a nepovirus, SLRSV is mechanically transmissible, particularly to herbaceous host
plants, and is naturally transmitted by the nematode Xiphinema diversicaudatum (Lister,
1964; Lamberti et al., 1986). Both adults and larvae transmit, and virus may be retained for
up to 84 days in the vector kept without plants. Seed transmission is reported for several
plant species and often exceeds 70% (Murant, 1976). Virus particles, characteristically for
a nepovirus, can be readily purified and high-titre antisera are obtained. All isolates studied
seem to be serologically identical (Murant, 1976), but not all populations of X.
diversicaudatum
are equally efficient in transmitting the virus. A peach isolate of SLRSV
was only transmitted by three out of nine nematode populations (Brown, 1985). No
serological relationship to other nepoviruses is known. Particles in Chenopodium quinoa

2
Strawberry latent ringspot 'nepovirus'

sap lost infectivity after 10 min at 52-58°C but were still infective after 50 days at room
temperature (Schmelzer, 1969).
DETECTION AND IDENTIFICATION
Symptoms
The disease is usually latent in strawberries and other fruit crops, i.e. no symptoms are
seen. Some strawberry cultivars show varying degrees of mottling and decline.
Morphology
Isometric, 30 nm in diameter, usually with obvious hexagonal outlines.
Detection and inspection methods
Specific antisera are available and provide the only reliable means of identification.
Chenopodium amaranticolor, C. murale and C. quinoa show chlorotic or necrotic local
lesions, systemic chlorosis and distortion, or sometimes necrosis or faint chlorotic mottle.
Cucumbers show chlorotic local lesions or none, systemic interveinal chlorosis or necrosis.
In summer, subsequent leaves are symptomless but contain virus, while in winter
symptoms may persist. Nicotiana rustica, Nicotiana tabacum and Petunia hybrida become
symptomlessly systemically infected. As local-lesion host for detection of SLRSV, C.
murale
is recommended.
The virus sometimes occurs in soils together with arabis mosaic nepovirus
(EPPO/CABI, 1996). The two viruses are serologically unrelated but some strains of each
give similar reactions in host plants.
MEANS OF MOVEMENT AND DISPERSAL
Under natural conditions, SLRSV is dispersed locally by the nematode Xiphinema
diversicaudatum
. Diseases caused by SLRSV typically show a patchy distribution because
of the slow lateral migration in soils of its nematode vector. The virus sometimes occurs in
soils together with arabis mosaic nepovirus, which is also transmitted by X.
diversicaudatum
. The virus infects seeds of several host plants but seed transmission is not
known in strawberry. International spread would most probably occur with vegetatively
propagated planting material.
PEST SIGNIFICANCE
Economic impact
SLRSV, being mostly latent in strawberries and other fruit crops, is of very minor
importance. It can cause some mottle and decline in certain strawberry cultivars. For more
information, see Rüdel (1985), Pelet (1989).
Control
Only virus-free plants should be propagated.
Phytosanitary risk
SLRSV is not considered to be a quarantine pest by any regional plant protection
organization. Since it is widespread in Europe and of very minor importance, it should
certainly not be considered as a quarantine pest. It is in any case one of the minor viruses to
be covered by a virus-free certification scheme, such as EPPO published (OEPP/EPPO,
1994) for strawberry.

Strawberry latent ringspot 'nepovirus'
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PHYTOSANITARY MEASURES
Traded strawberry planting material should meet the conditions of a virus-free certification
scheme. Diseased plant material should be eradicated and where possible soil should be
fumigated. SLRSV-free planting material for certification can readily be obtained by
selection.
BIBLIOGRAPHY
Brown, D.J.F. (1985) The transmission of two strains of strawberry latent ringspot virus by
populations of Xiphinema diversicaudatum. Nematologia Mediterranea 13, 217-223.
EPPO/CABI (1996) Arabis mosaic nepovirus. In: Quarantine pests for Europe. 2nd edition (Ed. by
Smith, I.M.; McNamara, D.G.; Scott, P.R.; Holderness, M.). CAB INTERNATIONAL,
Wallingford, UK.
Lamberti, F.; Roca, F.; Landriscina, S.; Ciancio, A. (1986) Seasonal transmissibility of strawberry
latent ringspot virus by Xiphinema diversicaudatum.
Nematologia Mediterranea 14, 173-179.
Lister, R. (1964) Strawberry latent ringspot: a new nematode-borne virus. Annals of Applied Biology
54, 167-176.
Murant, A.F. (1976) Strawberry latent ringspot virus. CMI/AAB Descriptions of Plant Viruses No.
126. Association of Applied Biologists, Wellesbourne, UK.
OEPP/EPPO (1994) Certification schemes No. 11, Pathogen-tested strawberry. Bulletin OEPP/EPPO
Bulletin 24 875-889.
Pelet, F. (1989) Small fruit viruses. Revue Suisse de Viticulture, Arboriculture, Horticulture 21, 113-
116.
Rüdel, M. (1985) Grapevine damage induced by particular virus-vector combinations.
Phytopathologia Mediterranea 24, 183-185.
Schmelzer, K. (1969) [SLRV from Euonymus, Robinia and Aesculus]. Phytopathologische Zeitschrift
66, 1-24.