Plant Viruses Online   

Descriptions and Lists from the VIDE Database

Cycas necrotic stunt nepovirus

Index

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

Data collated by M. Kusunoki, K. Hanada and M. Kameya, 1987.

Nomenclature

Acronym

CNSV

ICTV decimal code

18.0.3.0.013

Host range and symptoms

Natural host range and symptoms

Symptoms persist and vary seasonally.
• Cycas revoluta - twisted young leaves and chlorotic or necrotic spots of mature leaves, stunting.
• Daphne odora - mild mosaic.
• Aucuba japonica - vein clearing.
• Gladiolus spp. - symptomless.

Transmission

Transmitted by possibly a vector; a nematode. Virus transmitted by mechanical inoculation; transmitted by seed (about 30% in Chenopodium amaranticolor and over 80% in C. serotinum).

Geographical distribution

Spreads in Japan.

Experimental host range

Several (3-9) families susceptible.

Diagnostically susceptible host species and symptoms

• Tetragonia tetragonioides, Chenopodium amaranticolor, C. quinoa, C. serotinum - chlorotic local lesions or ringspots, then systemic mottling and necrosis.
• Celosia cristata - systemic mottling.
• Gomphrena globosa, Beta vulgaris - latent infection.
• Spinacia oleracea - latent infection.
• Cycas revoluta - chlorotic spotting, then systemic mottling and necrosis.

Diagnostically insusceptible host species

Cucumis sativus, Cucurbita moschata, Glycine max, Nicotiana clevelandii, Lycopersicon esculentum, Nicotiana tabacum, N. glutinosa, Phaseolus vulgaris, Pisum sativum, Catharanthus roseus, Datura stramonium.

Maintenance and propagation hosts

Chenopodium serotinum, C. quinoa, C. amaranticolor, Celosia cristata.

Assay hosts (Local lesions or Whole plants)

Chenopodium quinoa (L and W), C. amaranticolor (L) and then (W), C. murale (L) and then (W), C. serotinum (W), Tetragonia tetragonioides (L).

Susceptible host species

• Aucuba japonica
• Beta vulgaris
• Celosia cristata
• Chenopodium amaranticolor
• Chenopodium murale
• Chenopodium quinoa
• Chenopodium serotinum
• Cycas revoluta
• Daphne odora
• Gladiolus
• Gomphrena globosa
• Lycium chinense
• Spinacia oleracea
• Tetragonia tetragonioides

Insusceptible host species

• Brassica campestris ssp. chinensis
• Brassica oleracea var. botrytis
• Catharanthus roseus
• Cucumis sativus
• Cucurbita moschata
• Datura stramonium
• Dianthus barbatus
• Dianthus caryophyllus
• Fagopyrum esculentum
• Glycine max
• Helianthus annuus
• Lactuca sativa
• Lathyrus odoratus
• Lupinus albus
• Lycopersicon esculentum
• Nicotiana clevelandii
• Nicotiana glutinosa
• Nicotiana rustica
• Nicotiana tabacum
• Petunia × hybrida
• Phaseolus vulgaris
• Physalis floridana
• Pisum sativum
• Raphanus sativus
• Trifolium pratense
• Trifolium repens
• Vicia faba
• Vigna unguiculata
• Vigna unguiculata ssp. sesquipedalis
• Zinnia elegans

Families containing susceptible hosts

• Amaranthaceae (2/2)
• Aucubaceae (1/1)
• Chenopodiaceae (6/6)
• Cycadaceae (1/1)
• Iridaceae (1/1)
• Solanaceae (1/9)
• Tetragoniaceae (1/1)
• Thymelaeaceae (1/1)

Families containing insusceptible hosts

• Apocynaceae (1/1)
• Caryophyllaceae (2/2)
• Compositae (3/3)
• Cruciferae (3/3)
• Cucurbitaceae (2/2)
• Leguminosae-Papilionoideae (10/10)
• Polygonaceae (1/1)
• Solanaceae (8/9)

Sources of host-range data

Kusunoki et al. (1986).

Physical and biochemical properties

Properties of particles in sap

TIP: 60-65 °C. LIV: 18-24 days. DEP: log₁₀ minus 3. Leaf sap contains many virions.

Purification method

Kusunoki et al. (1986).

Particle morphology

Virions isometric; not enveloped; 28 nm in diameter; angular in profile; with a conspicuous capsomere arrangement.

Physical properties

Three sedimenting components in purified preparations; sedimentation coefficient of the fastest 112 S (B); of the other(s) 85 S (M). Density 1.472 g cm^-3 in CsCl (B), or 1.404 g cm^-3 in CsCl (M). A₂₆₀/A₂₈₀ ratio 1.67 (B), or 1.41 (M), or 1 (T).

Biochemical properties

Virions contain 24 % nucleic acid (B), or 12 % nucleic acid (M), or 0 % nucleic acid (T); 76 % protein (B), or 88 % protein (M), or 100 % protein (T).

Genome consists of RNA; single-stranded; linear. Total genome size 12.85 kb. Genome of two parts; largest (or only) genome part the larger 8.1 kb; the 2nd largest 4.75 kb. Genomic nucleic acid isolated by Hanada et al. (1986). Infectivity retained when deproteinised with phenol or detergent. Additional factor not required for infectivity.

Features of the genome

Non-genomic nucleic acid not found in the virions.

Features of proteins

Virion protein(s) three; M_r of the largest 71000. M_r of 2nd largest 65000. M_r of 3rd largest 56000.

Replication

Genome replicates in cytoplasm. Replication does not depend on a helper virus.

Cytopathology

Virions found in leaves; in cytoplasm, in Golgi apparatus, and in cell vacuoles; in plasmodesmata. Inclusions present in infected cells; are viroplasms (crystalline aggregates of virions and capsid protein); they contain virions. Other cellular changes: vesicular structures also occur in cytoplasm.

Taxonomy and relationships

Nepovirus: Comoviridae

Virus(es) with serologically unrelated virions

Arabis mosaic, cacao necrosis, cherry leaf roll, crimson clover latent, grapevine chrome mosaic, mulberry ringspot, myrobalan latent, tobacco ringspot, tomato ringspot and tomato black ring viruses.

Best tests for diagnosis

Use gel diffusion serology; species of Fabaceae and Solanaceae not infected despite `nepovirus-like' symptoms in Chenopodium plants.

Comments and References

References

• Hanada, K., Kusunoki, M. and Iwaki, M. (1986). Ann. Phytopath. Soc. Japan 52: 422.
• Kusunoki, M., Nagai, Y., Yamashita, S., Doi, Y. and Yora, K. (1975). Ann. Phytopath. Soc. Japan 41: 285.
• Kusunoki, M., Hanada, K., Iwaki, M., Chang, M.U., Doi, Y. and Yora, K. (1986). Ann. Phytopath. Soc. Japan 52: 302.

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.