Dianthovirus

The viruses of the genus Dianthovirus belong to the family Tombusviridae. Dianthoviruses are plant viruses. Examples of species of this genus include Carnation ringspot virus, Red clover necrotic mosaic virus and Sweet clover necrotic mosaic virus. The virus probably has a worldwide distribution (1). The viruses can be (and have been) transmitted via nematodes, by mechanical inoculation, by grafting of plants and by contact between infected hosts with previously uninfected host (1).

Particles
Viruses of this genus have round, non-enveloped capsids with icosahedral symmetry and a “hexagonal” appearance (1). The capsid is 31-35 nm in diameter. The buoyant density in CsCl of virions is between 1.363-1.366 g cm-3(1). They have a sedimentation coefficient of 126-132-135 S20w (1). The pH of their isoelectric point is 4.5 (1). The virions become inactive from about 80-90 °C and are inactive above those temperatures. They are viable in vitro for about 50-70 days (1). Treatment with ether either decreases or does not alter their infectivity (1). No lipids have so far been reported (1).

Genome
These viruses have segmented, bipartite genomes that are linear, positive-sense, single-stranded RNA (1). These genomes are about 5300 nucleotides in length (1). They have a methylated cap at the 5'-end whose sequence type is m7GpppA (1). The genome also codes for non-structural proteins as well as structural proteins (1). Three non-structural proteins have been found (1).