secoviridae secoviridae secoviridae is a family of viruses in the order picornavirales. plants serve as natural hosts. there are 8 genera and 86 species in this family, one of which is unassigned to a genus. the family was created in 2009 with the grouping of families sequiviridae, now dissolved, and comoviridae, now subfamily comovirinae, along with the then unassigned genera cheravirus, sadwavirus, and torradovirus. secoviridae structure of the cowpea mosaic virus based on pdb 2bfu virus classification (unranked): virus realm: riboviria kingdom: orthornavirae phylum: pisuviricota class: pisoniviricetes order: picornavirales family: secoviridae genera see text taxonomy the family includes the following genera (-virinae denotes subfamily and -virus denotes genus): comovirinae comovirus fabavirus nepovirus unassigned to a subfamily: cheravirus sadwavirus sequivirus torradovirus waikavirus lastly, one species is unassigned to a genus: strawberry latent ringspot virus. structure 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. genusstructuresymmetrycapsidgenomic arrangementgenomic segmentation sequivirusicosahedralpseudo t=3non-envelopedlinearmonopartite sadwavirusicosahedralpseudo t=3non-envelopedlinearsegmented nepovirusicosahedralpseudo t=3non-envelopedlinearsegmented fabavirusicosahedralpseudo t=3non-envelopedlinearsegmented comovirusicosahedralpseudo t=3non-envelopedlinearsegmented cheravirusicosahedralpseudo t=3non-envelopedlinearsegmented torradovirusicosahedralpseudo t=3non-envelopedlinearsegmented waikavirusicosahedralpseudo t=3non-envelopedlinearmonopartite life cycle 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. genushost detailstissue tropismentry detailsrelease detailsreplication siteassembly sitetransmission sequivirusplantsnoneviral movement; mechanical inoculationviral movementcytoplasmcytoplasmmechanical inoculation: aphids; mechanical inoculation: cavariella aegopodii; mechanical inoculation: cavariella pastinacae sadwavirusplantsnoneviral movement; mechanical inoculationviral movementcytoplasmcytoplasmnematodes; mites; thrips nepovirusplantsnoneviral movement; mechanical inoculationviral movementcytoplasmcytoplasmnematodes; mites; thrips fabavirusplantsnoneviral movement; mechanical inoculationviral movementcytoplasmcytoplasmmechanical inoculation: aphids comovirusplantsnoneviral movement; mechanical inoculationviral movementcytoplasmcytoplasmmechanical inoculation: beetles cheravirusplantsnoneviral movement; mechanical inoculationviral movementcytoplasmcytoplasmnematodes; mites; thrips torradovirusplantsnoneviral movement; mechanical inoculationviral movementcytoplasmcytoplasmunknown waikavirusgramineaephloem; phloem parenchyma; bundle sheathviral movementviral movementcytoplasmcytoplasmmechanical innocuation: aphids; mechanical innocuation: leafhoppers evolution 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.