Plant Viruses Online   

Descriptions and Lists from the VIDE Database

Orchid fleck (?) rhabdovirus

Index

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

Data collated by D.-E. Lesemann, 1986.

Nomenclature

Synonyms

dendrobium leaf streak virus, dendrobium virus, probably laelia red leafspot, short orchid rhabdovirus, orchid rhabdovirus, phalaenopsis chlorotic spot virus, phalaenopsis hybrid virus, phalaenopsis virus.

Acronym

OFV

ICTV decimal code

62.U.P.0.036

Host range and symptoms

Natural host range and symptoms

Symptoms persist.
• Cymbidium alexanderi - chlorotic or necrotic flecks.
• Phalaenopsis spp. and hybrids - chlorotic flecks.
• Renanthera spp. - chlorotic flecks, then sunken gray necrotic streaks with sharp margins and of variable size.
• Coelogyne spp., Dendrobium spp. (and hybrids), Miltonia spp., Odontoglossum spp., Oncidium spp. and Paphiopedilum spp. - chlorotic areas often with necrotic centres or rings.
• Vanda spp. - irregular chlorotic areas.

Transmission

Virus transmitted by mechanical inoculation; not transmitted by seed (some isolates infect better above 30ºC).

Geographical distribution

Spreads in Australia, Brazil, Germany, Japan, and the USA (Lesemann and Doraiswamy, 1975; Kitajima et al., 1974). Found, but with no evidence of spread, in New Zealand.

Experimental host range

Several (3-9) families susceptible.

Diagnostically susceptible host species and symptoms

• Dendrobium nobile, Cymbidium alexanderi - systemic chlorotic or necrotic spots or flecks.
• Nicotiana glutinosa, N. tabacum cvs Bright Yellows, White Burley, Xanthi-nc and KY-57 - chlorotic or necrotic local lesions, no systemic symptoms.
• Chenopodium quinoa - chlorotic local lesions.
• Vicia faba - brown necrotic local lesions.

Maintenance and propagation hosts

Cymbidium alexanderi.

Assay hosts (Local lesions or Whole plants)

Nicotiana glutinosa (L), Nicotiana tabacum (L), Chenopodium quinoa (L).

Susceptible host species

• Chenopodium amaranticolor
• Chenopodium quinoa
• Coelogyne
• Cymbidium alexanderi
• Dendrobium nobile
• Miltonia
• Nicotiana clevelandii
• Nicotiana glutinosa
• Nicotiana tabacum
• Odontoglossum
• Oncidium
• Paphiopedilum
• Phalaenopsis
• Renanthera
• Vanda
• Vicia faba

Families containing susceptible hosts

• Chenopodiaceae (2/2)
• Leguminosae-Papilionoideae (1/1)
• Orchidaceae (10/10)
• Solanaceae (3/3)

Physical and biochemical properties

Properties of particles in sap

LIV: 1 days (at 6ºC). DEP: log₁₀ minus 2. Leaf sap contains few virions, or contains many virions. Electron microscopy: for negative staining, mount sap in 2% AM pH 6.5. Virions appear smaller (32-35 × 100-140 nm) in leaf sections.

Purification method

Chang et al. (1976).

Particle morphology

Virions rhabdo- or bullet-shaped; not enveloped (or rarely enveloped); with a clear modal length; of 105-150 nm; 40-50 nm wide. Axial canal obvious; c. 15 nm in diameter. Basic helix obvious; pitch of basic helix 4.5 nm (Chang et al., 1976).

Replication

Replication does not depend on a helper virus.

Cytopathology

Virions found in mesophyll; in cytoplasm and in nuclei (where virions are commonly found to attach by one end to the inner nuclear membrane (Chang et al., 1976) or endoplasmic reticulum). Inclusions present in infected cells; are viroplasms and crystals in the nucleus (Chang et al., 1976; Lesemann and Doraiswamy, 1975); they contain virions. Other cellular changes: virions attached to the periphery of the nucleus.

Taxonomy and relationships

unassigned rhabdovirus

Additional comments on relationships

The virions of orchid fleck virus resemble those of plant rhabdoviruses, but are smaller, lack an outer envelope, and are still infective after treatment with detergents (e.g. Triton X-100), thus they may be equivalent to the internal component of rhabdovirus virions. In virion morphology and intracellular effects, orchid fleck virus closely resembles coffee ringspot (Kitajima and Costa, 1972) and citrus leprosis viruses (Kitajima et al., 1972).

Best tests for diagnosis

Electron microscopy will distinguish orchid fleck virus from cymbidium mosaic, odontoglossum ringspot and other orchid viruses.

Comments and References

References

• Chang, M.U., Arai, K., Doi, Y. and Yora, K. (1973). Ann. Phytopath. Soc. Japan 39: 171.
• Chang, M.U., Arai, K., Doi, Y. and Yora, K. (1976). Ann. Phytopath. Soc. Japan 42: 156.
• Doi, Y., Chang, M.U. and Yora, K. (1977). CMI/AAB Descr. Pl. Viruses No. 183, 3 pp.
• Doi, Y., Toriyama, S., Yora, K. and Asuyama, H. (1969). Ann. Phytopath. Soc. Japan 35: 388.
• Kitajima, E.W. and Costa, A.S. (1972). Cienc. Cult. 24: 542.
• Kitajima, E.W., Müller, G.W., Costa, A.S. and Yuki, W. (1972). Virology 50: 254.
• Kitajima, E.W., Blumenschein, A. and Costa, A.S. (1974). Phytopath. Z. 81: 280.
• Lesemann, D.-E. and Begtrup, J. (1971). Phytopath. Z. 71: 257.
• Lesemann, D.-E. and Doraiswamy, S. (1975). Phytopath. Z. 83: 27.
• Petzold, H. (1971). Phytopath. Z. 70: 45.

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.