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Descriptions and Lists from the VIDE Database

Maize rough dwarf fijivirus

Index

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

Data collated by R.G. Milne, 1984.

Nomenclature

Synonyms

virus del nanismo ruvido del mais.

Acronym

MRDV

Strains

type strain (TS), cereal tillering disease strain (CTD) (Boccardo and Milne, 1984; Lindsten and Gerhardson, 1971), mal de Rio Cuarto (MR4) (Boccardo and Milne, 1984; Nome et al., 1981).

ICTV decimal code

60.0.7.2.001

Host range and symptoms

Natural host range and symptoms

Symptoms persist.
• Avena sativa (CTD strain), Cynodon dactylon, Digitaria sanguinalis, Echinochloa crus-galli, Hordeum vulgare (CTD strain), Lolium perenne, Setaria verticillata, Triticum aestivum (CTD strain), Zea mays (dent, not flint cultivars) - stunting, dark green colour, enations on veins of leaves and sheaths, longitudinal splitting of roots, flowers suppressed.

Transmission

Transmitted by a vector; an insect; Delphacodes propinqua, Dicranotropis hamata, Laodelphax striatellus, Javasella pellucida, Sogatella vibix; Delphacidae. Transmitted in a persistent manner. Virus retained when the vector moults; multiplies in the vector; transmitted congenitally to the progeny of the vector (one unconfirmed report); transmitted by mechanical inoculation (injection; but very inefficient); not transmitted by grafting; not transmitted by contact between plants; not transmitted by seed; not transmitted by pollen.

Geographical distribution

Spreads in Argentina, the former Czechoslovakia, France, Israel, Italy, Norway, Spain, Sweden, and the former Yugoslavia.

Experimental host range

Few (<3) families susceptible.

Diagnostically susceptible host species and symptoms

• Hordeum vulgare cv. Delesa - stunting.
• Zea mays American yellow dent hybrids; Wisconsin 641 AA - stunting, dark green colour, pale yellow enations on abaxial surface of leaves and leaf sheaths.

Diagnostically insusceptible host species

Saccharum spp., Sorghum halepense (susceptible to the Chinese virus), Stipa bromoides, probably all non-Gramineae.

Maintenance and propagation hosts

Hordeum vulgare, Triticum aestivum, Zea mays.

Assay hosts (Local lesions or Whole plants)

Hordeum vulgare (W), Triticum aestivum (W), Zea mays (W).

Susceptible host species

• Avena sativa
• Cynodon dactylon
• Digitaria sanguinalis
• Echinochloa crus-galli
• Hordeum vulgare
• Lolium perenne
• Oryza sativa
• Secale cereale
• Setaria italica
• Setaria verticillata
• Triticum aestivum
• Zea mays

Insusceptible host species

• Chloris gayana
• Saccharum officinarum
• Sorghum halepense
• Stipa bromoides

Families containing susceptible hosts

• Gramineae (12/16)

Families containing insusceptible hosts

• Gramineae (4/16)

Sources of host-range data

Milne and Lovisolo (1977).

Physical and biochemical properties

Properties of particles in sap

Leaf sap contains few virions, or contains many virions (few virions in whole leaf sap, many in sap from enations). Electron microscopy: for whole virions avoid neutral PTA, use 2% aqueous UA. No special treatment for subvirions.

Purification method

Milne et al. (1973); Boccardo and Milne (1981).

Particle morphology

Virions isometric; not enveloped; 70 nm in diameter; rounded in profile, or angular in profile; with a conspicuous capsomere arrangement.

Physical properties

Two sedimenting components in purified preparations (whole and subvirions); sedimentation coefficient 400 S (for subviral non-infectious virions).

Biochemical properties

Virions 0 % lipid.

Genome consists of RNA; double-stranded; linear. Total genome size 26.169 kb. Genome of 10 parts (named S1-10); largest (or only) genome part the largest 3.9 kb (pairs); the 2nd largest 3.2 kb (pairs); the 3rd largest 3.15 kb (pairs); the 4th largest 3.15 kb (pairs); the 5th largest 3.1 kb (pairs); the 6th largest and other parts 2.293 kb (pairs; also 2.198, 1.735, 1.728 and 1.715 kb pairs). Genomic nucleic acid isolated by Boccardo and Milne (1975). Additional factor required for infectivity; proteins from the virions; isolated nucleic acid is not infectious.

NCBI sequence data (Entrez search)

Sequence database accession code(s)

• X55701 Em(40)_un:MRDVS6 Gb(84)_un:MRDVS6 Maize rough dwarf virus (MRDV) mRNA for genomic segment S6. 3/91 2,193bp. 1 sequence.

Features of the genome

Non-genomic nucleic acid not found in the virions.

Features of proteins

Virion protein(s) six; M_r of the largest 139000. M_r of 2nd largest 125000. M_r of 3rd largest 123000. M_r of 4th largest 111000. M_r of 5th largest 97000. M_r of 6th largest and smaller, 64000. Method of preparation: Boccardo and Milne (1975).

Replication

Genome replicates in cytoplasmic viroplasms. Coat protein mRNA translated in the cytoplasm. Replication does not depend on a helper virus.

Cytopathology

Virions found in phloem enations; in cytoplasm. Inclusions present in infected cells; are crystals in the cytoplasm, or viroplasms (containing immature virions), or unusual in shape; tubular structures some 100 nm diameter; they contain virions. Other cellular changes: cell wall proliferation and cell enlargement.

Taxonomy and relationships

Fijivirus: Reoviridae

Virus(es) with serologically related virions

The virus is so closely related to rice black streaked dwarf virus, that it may be the same species, it is more distantly related to pangola stunt virus.

Virus(es) with serologically unrelated virions

Oat sterile dwarf, rice ragged stunt and sugarcane Fiji disease viruses.

Comments and References

General comments

The virus has been reported from China, but it may be that the virus was incorrectly identified, and was rice black-streaked dwarf virus, which is common in the region.

References

• Boccardo, G. and Milne, R.G. (1975). Virology 68: 79.
• Boccardo, G. and Milne, R.G. (1981). J. virol. Meth. 3: 109.
• Boccardo, G. and Milne, R.G. (1984). CMI/AAB Descr. Pl. Viruses No. 294, 7 pp.
• Conti, M. (1984). In: Current Topics in Vector Research; ed. K.F. Harris. Praeger Scientific, New York.
• Francki, R.I.B. and Boccardo, G. (1983). In: The Reoviridae. p. 155; ed. K.W. Joklik. Plenum Press, New York.
• Francki, R.I.B., Milne, R.G. and Hatta, T. (1984). In: An Atlas of Plant Viruses. Vol. 1. CRC Press, Boca Raton, Florida.
• Harpaz, I. (1959). Nature, Lond. 184: 77.
• Lindsten, K. and Conti, M. (1977). Annls. Phytopath. 9: 30.
• Lindsten, K. and Gerhardson, B. (1971). Nat. Swed. Inst. Pl. Prot. Count. S. 14: 285.
• Lovisolo, O. (1971). CMI/AAB Descr. Pl. Viruses No. 72, 4 pp.
• Marzachi, C., Boccardo, G. and Nuss, D.L. (1991). Virology 180: 518.
• Milne, R.G. and Lovisolo, O. (1977). Adv. Virus Res. 21: 267.
• Milne, R.G. and Luisoni, E. (1977). Virology 80: 12.
• Milne, R.G., Conti, M. and Lisa, V. (1973). Virology 53: 130.
• Nome, S.F., Lenardon, S.L., Raju, B.C., Laguna, I.G., Lowe, S.K. and Docampo, D. (1981). Phytopath. Z. 101: 7.

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.