| Group IV ((+)ssRNA)|
| Nepovirus, Grapevine fanleaf virus, Tomato ringspot virus, Tobacco ringspot virus, Cowpea mosaic virus|
Secoviridae is a family of viruses in the order Picornavirales. Plants serve as natural hosts. There are currently 73 species in this family, divided among 11 genera.
Viruses in Secoviridae are non-enveloped, with icosahedral geometries, and T=pseudo3 symmetry. The diameter is around 25-30 nm. Genomes are linear and segmented, bipartite, around 24-7kb in length.
Viral replication is cytoplasmic. Entry into the host cell is achieved by penetration into the host cell. Replication follows the positive stranded RNA virus replication model. Positive stranded RNA virus transcription is the method of transcription. The virus exits the host cell by tubule-guided viral movement. Plants serve as the natural host. Transmission routes are mechanical.
The subfamily Comovirinae evolved ~1,000 years ago with extant species diversifying between 50 and 250 years ago. This time period coincides with the intensification of agricultural practices in industrial societies.
The mutation rate has been estimated to be 9.29×10−3 to 2.74×10−3 subs/site/year.