Tobacco mosaic virus (TMV) is a positive-sense single-stranded RNA virus species in the genus Tobamovirus that infects a wide range of plants, especially tobacco and other members of the family Solanaceae. The infection causes characteristic patterns, such as "mosaic"-like mottling and discoloration on the leaves. TMV was the first virus to be discovered. Although it was known from the late 19th century that a non-bacterial infectious disease was damaging tobacco crops, it was not until 1930 that the infectious agent was determined to be a virus. It is the first pathogen identified as a virus.
The parsnip is a root vegetable closely related to carrot and parsley, all belonging to the flowering plant family Apiaceae. It is a biennial plant usually grown as an annual. Its long, tap root has cream-colored skin and flesh, and, left in the ground to mature, it becomes sweeter in flavor after winter frosts. In its first growing season, the plant has a rosette of pinnate, mid-green leaves. If unharvested, in its second growing season it produces a flowering stem topped by an umbel of small yellow flowers, later producing pale brown, flat, winged seeds. By this time, the stem has become woody and the tap root inedible.
Caulimoviridae is a family of viruses infecting plants. There are currently 85 species in this family, divided among 10 genera. Viruses belonging to the family Caulimoviridae are termed double-stranded DNA (dsDNA) reverse-transcribing viruses i.e. viruses that contain a reverse transcription stage in their replication cycle. This family contains all plant viruses with a dsDNA genome that have a reverse transcribing phase in their lifecycle.
Closteroviridae is a family of viruses. Plants serve as natural hosts. There are currently 56 species in this family, divided among 4 genera, seven species of which are unassigned. Diseases associated with this family include: yellowing and necrosis, particularly affecting the phloem.*
Tobamovirus is a genus of positive-strand RNA viruses in the family Virgaviridae. Many plants, including tobacco, potato, tomato, and squash, serve as natural hosts. Diseases associated with this genus include: necrotic lesions on leaves. The name Tobamovirus comes from the host and symptoms of the first virus discovered.
Potyvirus is a genus of viruses in the family Potyviridae. Plants serve as natural hosts. There are currently 183 species in this genus including the type species Potato virus Y. The genus is named after the type virus. Potyviruses account for ~30% of the currently known plant viruses. Like begomoviruses, members of this genus may cause significant losses in agricultural, pastoral, horticultural and ornamental crops. More than 200 species of aphids spread potyviruses and most are from the subfamily Aphidinae.
Begomovirus is a genus of viruses, in the family Geminiviridae. They are plant viruses that as a group have a very wide host range, infecting dicotyledonous plants. Worldwide they are responsible for a considerable amount of economic damage to many important crops such as tomatoes, beans, squash, cassava and cotton. There are currently 424 species in this genus including the type species Bean golden yellow mosaic virus.
Turnip yellow mosaic virus (TYMV) is an isometric Tymovirus of the family Tymoviridae. Its host range is confined almost entirely to plants in the genus Brassica in western Europe, which includes cabbages, cauliflower and broccoli. Infection causes bright yellow mosaic disease showing vein clearing and molting of plant tissues.
Asparagus virus 1 (AV-1) is one of the nine known viruses that affects asparagus plants. It is in the Potyviridae family. Initially reported by G. L Hein in 1960, it is a member of the genus Potyvirus and causes no distinct symptoms in asparagus plants. The only known plant that can get AV-1 is asparagus plants. It is spread by aphids vectors, which means that aphids do not cause the AV-1, but they do spread it.
Malva sylvestris is a species of the mallow genus Malva in the family of Malvaceae and is considered to be the type species for the genus. Known as common mallow to English-speaking Europeans, it acquired the common names of cheeses, high mallow and tall mallow as it migrated from its native home in Western Europe, North Africa and Asia through the English-speaking world.
Orthotospovirus is a genus of negative-strand RNA viruses, in the family Tospoviridae of the order Bunyavirales, which infects plants. Tospoviruses take their name from the type species tomato spotted wilt orthotospovirus (TSWV) which was discovered in Australia in 1919. The type species remained the only member of the family until the early 1990s when genetic characterisation of plant viruses became more common. There are now at least twenty species in the genus with more being discovered on a regular basis. Member viruses infect over eight hundred plant species from 82 different families.
Potexvirus is a genus of pathogenic viruses in the order Tymovirales, in the family Alphaflexiviridae. Plants serve as natural hosts. There are currently 38 species in this genus including the type species Potato virus X. Diseases associated with this genus include: mosaic and ringspot symptoms. The genus name comes from the type species POTato Virus X).
Carlavirus, formerly known as the "Carnation latent virus group", is a genus of viruses in the order Tymovirales, in the family Betaflexiviridae. Plants serve as natural hosts. There are currently 53 species in this genus including the type species Carnation latent virus. Diseases associated with this genus include: mosaic and ringspot symptoms.
Malva mosaic virus is a plant pathogenic virus of the family Alphaflexiviridae. It was discovered in 2008 and infects the common mallow. Its genome is about 6,800 nucleotides in length and it contains five major open reading frames.
Apium virus Y (ApVY) is a plant pathogenic virus in the genus Potyvirus and the virus family Potyviridae.
Squash mosaic virus (SqMV) is a mosaic virus disease common in squash plants and other plants, including melons, of the family Cucurbitaceae. It occurs worldwide. It is transmitted primarily by beetles, including the leaf beetle, spotted cucumber beetle, and 28-spotted ladybird beetle, as well as some other beetles. Plants are infected by the saliva expelled by the beetles as they feed upon the plant. The beetles acquire the virus by feeding upon an infected plant and can retain the virus in their bodies for up to 20 days. Unlike some other mosaic viruses that infect squashes, SqMV is not spread by aphids. In melons it can be spread by seeds. The results are dark green mosaic, blistering, vein clearing, yellowing of leaves, and hardening. Symptoms include "pronounced chlorotic mottle, green veinbanding, and distortion of leaves". Fruits of infected plants are also affected, becoming mottled and misshaped. There are two strains of this virus: strain 1 has a greater effect on melons than squash while the opposite is true of strain 2.
Soybean vein necrosis orthotospovirus is a plant pathogenic virus of soybeans. SVNV is a relatively new virus, which was discovered in Tennessee in 2008 and has recently been found in many US states from the Southeast and East coast to some western states including CA. This pathogen initially causes intraveinal chlorosis (yellowing) in leaves. This chlorosis then spreads throughout the leaf and eventually these chlorotic areas can become necrotic. It is a member of the order Bunyavirales, family Tospoviridae and genus Orthotospovirus, which is the only genus within this virus family that infects plants. Like other members of Bunyavirales, this virus is enveloped and has a negative sense single-stranded RNA (−ssRNA) genome composed of three genomic segments. It encodes proteins on the M and S segments in an ambisense manner.
Badnavirus is a genus of viruses, in the family Caulimoviridae order Ortervirales. Plants serve as natural hosts. There are currently 59 species in this genus including the type species Commelina yellow mottle virus. Diseases associated with this genus include: CSSV: leaf chlorosis, root necrosis, red vein banding in young leaves, small mottled pods, and stem/root swelling followed by die-back. Infection decreases yield by 25% within one year, 50% within two years and usually kills trees within 3–4 years.
Caulimovirus is a genus of viruses, in the family Caulimoviridae order Ortervirales. Plants serve as natural hosts. There are currently 13 species in this genus including the type species Cauliflower mosaic virus. Diseases associated with this genus include: vein-clearing or banding mosaic.
Cavemovirus is a genus of viruses, in the family Caulimoviridae order Ortervirales. Plants serve as natural hosts. There are currently only two species in this genus including the type species Cassava vein mosaic virus. Diseases associated with this genus include: vein-clearing or banding mosaic.
