Plant Viruses Online   

Descriptions and Lists from the VIDE Database

White clover 2 betacryptovirus

Index

• Nomenclature
• Host range, transmission and symptoms
• Physical and biochemical properties
• Taxonomy and relationships
• Comments and References

Data collated by A.A. Brunt, 1991.

Nomenclature

Acronym

WCCV-2

ICTV decimal code

49.0.4.0.005

Host range and symptoms

Natural host range and symptoms

• Trifolium repens - no symptoms.

Transmission

Virus not transmitted by mechanical inoculation; not transmitted by grafting; transmitted by seed.

Geographical distribution

Found, but with no evidence of spread, in Europe, Japan, New Zealand and the U.S.A.

Experimental host range

Few (<3) families susceptible.

Diagnostically susceptible host species and symptoms

• none known.

Maintenance and propagation hosts

Trifolium repens containing no other viruses.

Susceptible host species

• Trifolium repens

Families containing susceptible hosts

• Leguminosae-Papilionoideae (1/1)

Purification method

Boccardo et al. (1985).

Physical and biochemical properties

Particle morphology

Virions isometric; not enveloped; 38 nm in diameter; rounded in profile; with a conspicuous capsomere arrangement.

Physical properties

One sedimenting component in purified preparations. Density 1.375 g cm^-3 in CsCl. A₂₆₀/A₂₈₀ ratio 1.31.

Biochemical properties

Virions contain 24 % nucleic acid; 76 % protein.

Genome consists of RNA; double-stranded; linear. Total genome size 4.31 kb (pairs). Genome of two parts; largest (or only) genome part the larger 2.238 kb (pairs); the 2nd largest 2.072 kb (pairs).

Cytopathology

Virions found in all parts of the host plant; in cytoplasm. Inclusions absent from infected cells.

Taxonomy and relationships

Betacryptovirus: Partitiviridae (the type species)

Virus(es) with serologically related virions

Red clover 2 and hop trefoil 2 betacryptoviruses.

Additional comments on relationships

Complementary cDNA probes to white clover 2 betacryptovirus failed to detect any homology with white clover 1 and 3 alphacryptoviruses.

Comments and References

General comments

This virus was originally described as white clover temperate virus (Natsuaki et al., 1984), and was shown later to be a mixture of white clover cryptic viruses 1, 2 and 3 (Natsuaki et al., 1986).

References

• Boccardo, G., Lisa, V. and Milne, R.G. (1983). In: Double-Stranded RNA Viruses, p. 425; eds R.W. Compans and D.H.L. Bishop. Elsevier, New York.
• 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. and Milne, R.G. (1988). AAB Descr. Pl. Viruses No. 332, 4 pp.
• Luisoni, E., Milne, R.G., Accotto, G.P. and Boccardo, G. (1987). Intervirology 28: 144.
• Natsuaki, K.T., Natsuaki, T., Okuda, S., Teranaka, M., Yamashita, S. and Doi, Y. (1984). J. agric. Sci., Tokyo Nogyo Daigaku 29: 49.
• Natsuaki, T., Natsuaki, K.T., Okuda, S., Teranaka, M., Milne, R.G., Boccardo, G. and Luisoni, E. (1986). Intervirology 25: 69.

Cite this publication as: Brunt, A.A., Crabtree, K., Dallwitz, M.J., Gibbs, A.J., Watson, L. and Zurcher, E.J. (eds.) (1996 onwards). `Plant Viruses Online: Descriptions and Lists from the VIDE Database. Version: 20^th August 1996.' URL http://biology.anu.edu.au/Groups/MES/vide/

Dallwitz (1980) and Dallwitz, Paine and Zurcher (1993) should also be cited.