sequivirus sequivirus sequivirus is a genus of viruses in the order picornavirales, in the family secoviridae. plants serve as natural hosts. there are three species in this genus. diseases associated with this genus include: pyfv: vein-yellowing, yellow flecks and yellow/green mosaic symptoms in parsnip, and ‘yellow net', followed by yellow spots and leaf distortion in celery. sequivirus virus classification (unranked): virus realm: riboviria kingdom: orthornavirae phylum: pisuviricota class: pisoniviricetes order: picornavirales family: secoviridae genus: sequivirus taxonomy the genus contains the following species: carrot necrotic dieback virus dandelion yellow mosaic virus parsnip yellow fleck virus structure viruses in sequivirus are non-enveloped, with icosahedral geometries, and t=pseudo3 symmetry. the diameter is around 25-30 nm. genomes are linear and non-segmented, around 9kb in length. genusstructuresymmetrycapsidgenomic arrangementgenomic segmentation sequivirusicosahedralpseudo 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. the virus is transmitted via a vector (insects (aphids). transmission routes are vector and mechanical. genushost detailstissue tropismentry detailsrelease detailsreplication siteassembly sitetransmission sequivirusplantsnoneviral movement; mechanical inoculationviral movementcytoplasmcytoplasmmechanical inoculation: aphids; mechanical inoculation: cavariella aegopodii; mechanical inoculation: cavariella pastinacae