Plant Viruses Online   

Descriptions and Lists from the VIDE Database

Hop trefoil 3 alphacryptovirus

Index

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

Data collated by E. Luisoni, 1991.

Nomenclature

Acronym

HTCV-3

ICTV decimal code

49.0.3.0.011

Host range and symptoms

Natural host range and symptoms

• Medicago lupulina - symptomless.

Transmission

Transmitted by means not involving a vector. Virus not transmitted by mechanical inoculation; not transmitted by grafting; not transmitted by contact between plants; transmitted by seed.

Geographical distribution

Found, but with no evidence of spread, in Italy, but probably widespread elsewhere.

Maintenance and propagation hosts

Medicago lupulina.

Susceptible host species

• Medicago lupulina

Families containing susceptible hosts

• Leguminosae-Papilionoideae (1/1)

Sources of host-range data

Boccardo et al. (1987); Luisoni et al. (1987).

Physical and biochemical properties

Properties of particles in sap

Leaf sap contains few virions (very few). Electron microscopy: use ISEM; to aid negative stain adhesion use carbon-coated Formvar films treated with glow-discharge in air at 0.1 torr.

Purification method

Luisoni et al. (1987).

Particle morphology

Virions isometric; not enveloped; 30 nm in diameter; rounded in profile; without a conspicuous capsomere arrangement.

Physical properties

One sedimenting component in purified preparations. Density 1.35-1.37 g cm^-3 in CsCl.

Biochemical properties

Genome consists of RNA; double-stranded; linear. Total genome size 5.15 kb (pairs). Genome of three parts (in the mixture hop trefoil cryptic viruses 2 and 3); largest (or only) genome part the largest 2.05 kb (pairs); the 2nd largest 1.65 kb (pairs); the 3rd largest 1.45 kb (pairs). Genomic nucleic acid isolated by Boccardo et al. (1985); Luisoni et al. (1987).

Taxonomy and relationships

Alphacryptovirus: Partitiviridae

Virus(es) with serologically related virions

Vicia cryptic virus.

Virus(es) with serologically unrelated virions

Alfalfa 1, beet 1 and 2, carnation, poinsettia, radish yellow edge, ryegrass and white clover 3 cryptoviruses.

Best tests for diagnosis

ISEM and decoration may distinguish between hop trefoil 2 betacryptovirus and hop trefoil 1 and 3 alphacryptoviruses. The detection, by PAGE, of dsRNAs similar to those found for the mixture hop trefoil cryptic viruses 2 and 3 can confirm serological results.

Comments and References

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.

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.