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00.049.0.04.003. Hop trefoil cryptic virus 2

Cite this publication as: ICTVdB Management (2006). 00.049.0.04.003. Hop trefoil cryptic virus 2. In: ICTVdB - The Universal Virus Database, version 4. Büchen-Osmond, C. (Ed), Columbia University, New York, USA

Cite this site as: ICTVdB - The Universal Virus Database, version 4. http://www.ncbi.nlm.nih.gov/ICTVdb/ICTVdB/

Table of Contents

Isolate Description

Location: in plants grown from seeds imported from Poland and Denmark; Italy.

Host of Isolate and Habitat Details
Source of isolate: Medicago lupulina.

Natural host and symptoms
Medicago lupulina — symptomless.

Reference to Isolation Report
Boccardo et al. (1987, Luisoni et al. (1987).

Classification

This is a description of a plant virus at the species level with data on all virus properties from morphology to genome, replication, antigenicity and biological properties.

ICTVdB Virus Code: 00.049.0.04.003. Virus accession number: 49004003. Obsolete virus code: 49.0.4.0.003; superceded accession number: 49040003.

Name, Synonyms and Lineage

ICTV approved acronym: HTCV-2. Virus is an ICTV approved species of the genus 00.049.0.04. Betacryptovirus in the family 00.049. Partitiviridae.

Virion Properties

Morphology

Virions consist of a capsid. Virus capsid is not enveloped, round with icosahedral symmetry. The nucleocapsid is isometric and has a diameter of 38 nm. Capsids appear round. The capsomer arrangement is clearly visible.

Electron microscopic preparation and references: Virus preparation contains few virions (very few). Use ISEM. To aid negative stain adhesion of purified preparations, it is best to use carbon-coated Formvar-film that has been treated with glow-discharge in air at 0.1 torr. Reference for electron microscopic methods: Luisoni et al. (1987).

Nucleic Acid

The genome is segmented; tripartite, segements are distribute among 3 particle types of different size (in the mixture hop trefoil cryptic viruses 2 and 3, consists of three segments of linear, double -stranded RNA. The complete genome is 5150 nucleotides long. The genome is sequenced, and complete sequence is about 2050 nucleotides long, is sequenced and complete sequence is about 1650 nucleotides long, is sequenced, but only an estimate is given, complete sequence is 1450 nucleotides long. Reference to nucleotide sequence Boccardo et al. (1985, Luisoni et al. (1987).

Proteins

The viral genome encodes structural proteins.

Lipids

Lipids are not reported.

Antigenicity

The virus is serologically related to red clover 2 and white clover 2 betacryptoviruses.

No serological relation to alphacryptoviruses.

Diagnostics and Reference Collections

The best tests for diagnosis are ISEM and decoration may distinguish between hop trefoil 2 virus and hop trefoil 1 and 3 alphacryptoviruses. ELISA may be useful but it does not distinguish between 1, 2 and 3. The detection by PAGE of dsRNAs similar to those found for the mixture hop trefoil cryptic viruses 2 and 3 can confirm serology.

Biological Properties

Natural Host

Domain
Viral hosts belong to the Domain Eucarya.

Domain Eucarya
Kingdom Plantae.

Kingdom Plantae
Phylum Magnoliophyta (Angiosperms, Class Magnoliopsida (Dicotyledonae).

Transmission and Vector Relationships

Virus is not transmitted by a vector. Virus is not transmitted by mechanical inoculation; not transmitted by grafting; not transmitted by contact between hosts; transmitted by seeds.

Experimental Hosts and Symptoms

Under experimental conditions susceptibility to infection by virus is found in few families. Susceptible host species are found in the Family Leguminosae-Papilionoideae. The following species were susceptible to experimental virus infection: Medicago lupulina.

Maintenance and Propagation Hosts

Most commonly used maintenance and propagation host species are Medicago lupulina.

References to host data: Boccardo et al. (1987, Luisoni et al. (1987).

Geographical Distribution

The virus is found, but with no evidence of proliferation, in in Italy, in plants grown from seeds from Denmark and Poland, probably widespread elsewhere.

References

Boccardo, G., Milne, R.G., Luisoni, E., Lisa, V. and Accotto, G.P. (1985). Virology 147: 29.

Boccardo, G., Lisa, V., Luisoni, E. and Milne, R.G. (1987). Adv. Virus Res. 32: 171.

Luisoni, E., Milne, R.G., Accotto, G.P. and Boccardo, G. (1987). Intervirology 28: 144.

The following generic references are cited in the most recent ICTV Report.

VIDEdB, the plant virus database developed at the Australian National University by Adrian J. Gibbs and collaborators, contains an earlier description with the number 401 by E. Luisoni, 1991.



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DELTA - DEscription Language for TAxonomy developed by Dr Mike Dallwitz, Toni Paine and Eric Zurcher, CSIRO Entomology, Canberra, Australia. ICTVdB - The Universal Virus Database, developed for the International Committee on Taxonomy of Viruses by Dr Cornelia Büchen-Osmond is written in DELTA. The virus descriptions in ICTVdB are coded by, or using data from experts in the field of virology or members ICTV. The character list is the underlying code. All virus descriptions are based on the character list and natural language translations are automatically generated and formatted for display on the Web from the descriptions in DELTA-format. The description has been generated automatically from DELTA files. DELTA - DEscription Language for TAxonomy developed by Dr Mike Dallwitz, Toni Paine and Eric Zurcher, CSIRO Entomology, Canberra, Australia.

ICTVdB - The Universal Virus Database, developed for the International Committee on Taxonomy of Viruses (ICTV) by Dr Cornelia Büchen-Osmond, is written in DELTA. The virus descriptions in ICTVdB are coded by ICTV members and experts, or by the ICTVdB Management using data provided by the experts, the literature or the latest ICTV Report. The character list is the underlying code. All virus descriptions are based on the character list and natural language translations from the encoded descriptions are automatically generated and formatted for display on the Web.

Developer of the DELTA software: M. J. Dallwitz, T. Paine and E. Zurcher

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Last updated on 25 April 2006 by Cornelia Büchen-Osmond
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