A satellite is a subviral agent that depends on the coinfection of a host cell with a helper virus for its replication. Satellites can be divided into two major classes: satellite viruses and satellite nucleic acids. Satellite viruses, which are most commonly associated with plants, but are also found in mammals, arthropods, and bacteria, encode structural proteins to enclose their genetic material, which are therefore distinct from the structural proteins of their helper viruses. Satellite nucleic acids, in contrast, do not encode their own structural proteins, but instead are encapsulated by proteins encoded by their helper viruses. The genomes of satellites range upward from 359 nucleotides in length for satellite tobacco ringspot virus RNA (STobRV).
Potato leafroll virus (PLRV) is a member of the genus Polerovirus and family Luteoviridae. The phloem limited positive sense RNA virus infects potatoes and other members of the family Solanaceae. PLRV was first described by Quanjer et al. in 1916. PLRV is transmitted by aphids, primarily the green peach aphid, Myzus persicae. PLRV is one of the most important potato viruses worldwide but particularly devastating in countries with limited resources and management. It can be responsible for individual plant yield losses of over 50%. One estimate suggests that PLRV is responsible for an annual global yield loss of 20 million tons. Symptoms include chlorosis, necrosis and leaf curling.
Closterovirus, also known as beet yellows viral group, is a genus of viruses, in the family Closteroviridae. Plants serve as natural hosts. There are currently 16 species in this genus. Diseases associated with this genus include: yellowing and necrosis, particularly affecting the phloem. This genus has a probably worldwide distribution and includes among other viral species the Beet yellows virus and Citrus tristeza virus, rather economically important plant diseases. At least some species require vectors such as aphids or mealybugs for their transmission from plant to plant.
Grapevine fanleaf virus (GFLV) is a plant pathogenic virus of the family Secoviridae. It infects grapevines, causing chlorosis of the leaves and lowering the fruit quality. Because of its effect on grape yield, GFLV is a pathogen of commercial importance. It is transmitted via a nematode vector, Xiphinema index. This nematode acquires the virus through feeding on roots of an infected plant, and passes it on in the same manner.
Pseudococcus viburni is a close relative of the grape mealybug and a pest of the vineyards of New Zealand, the Central Coast of California, and the tea gardens of northern Iran. Unlike the grape mealybug, the obscure mealybug is not native to California, having most likely been introduced to the region from either Australia or South America in the latter part of the 19th century.
Secoviridae is a family of viruses in the order Picornavirales. Plants serve as natural hosts. There are currently 86 species in this family, divided among 8 genera or not assigned 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.
Laura is a mid-season-ripening, firm-fleshed, edible potato. The Laura potato is red-skinned with a rich potato-yellow flesh color and an oval shape. It was first recognised in 1998 in Austria. The depth of the eyes is between flat and very flat.
Grapevine leafroll-associated virus (GLRaV) is a name for a group of viruses infecting grapevine in the genus Closterovirus.
Grapevine virus A (GVA) is a moderately common genetic virus that affects Vitis vinifera and American Vitis grapevine species throughout the world and can be fatal if not treated. Grapevine virus A is in the family Betaflexiviridae and genus Vitivirus. The common name for this virus is grapevine closterovirus. Common symptoms in infected grapevines include stem pitting. Although there is a treatment available to cure infected grapevines, it is not one hundred percent effective, so preventative measures are the best solution to the virus. Every inhabited continent on the globe has had breakouts of grapevine closterovirus due to the complex genetic makeup of the virus. Grapevine virus A has a single-stranded RNA genome, which is similar to that of Grapevine virus B. There are multiple strains of the virus that vary both molecularly and biologically which account for the slightly different symptoms exhibited by infected plants.
Grapevine virus B is plant virus species in the genus Vitivirus. It is associated with rugose wood symptoms in grapevine.
Grapevine virus D (GVB) is a plant virus species in the genus Vitivirus, associated with rugose wood condition of grapevine.
Grapevine leafroll-associated virus 1 (GRLaV-1) is a virus infecting grapevine in the genus Ampelovirus.
Grapevine leafroll-associated virus 3 (GLRaV-3) is a grapevine infecting virus in the family Closteroviridae, genus Ampelovirus.
Grapevine leafroll-associated virus 4 (GRLaV-4) is a virus infecting grapevine in the genus Ampelovirus.
Ampelovirus is a genus of viruses, in the family Closteroviridae. Plants serve as natural hosts. There are currently 12 species in this genus including the type species Grapevine leafroll-associated virus 3. Diseases associated with this genus include: yellowing and necrosis, particularly affecting the phloem.
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.
Polerovirus is a genus of viruses, in the family Luteoviridae. Plants serve as natural hosts. There are currently 26 species in this genus including the type species Potato leafroll virus. Diseases associated with this genus include: PLRV causes prominent rolling of the leaves of potato and a stiff upright habit of the plants; necrosis of the phloem and accumulation of carbohydrates in the leaves.
Velarivirus is a genus of viruses, in the family Closteroviridae. Plants serve as natural hosts. There are currently seven species in this genus, including the type species Grapevine leafroll-associated virus 7. Diseases associated with this genus include: GLRaV-7: symptomless in white-berried grapevine cultivar from Albania. However, it induces leafroll symptoms onto grafted cv. cabernet.
Grapevine red blotch disease (GRBD), also known simply as red blotch, is a viral disease of grapevine. The disease is caused by a single-stranded circular DNA virus, the species grapevine red blotch virus, also known as grapevine red blotch-associated virus, GRBaV. First identified in California, the disease affects grapevines of all varieties and is internationally present. Symptoms typically include red blotches on the leaves of red varieties and in pale green or pale yellow blotches on white varieties. It significantly reduces the value of juice collected from the berries of affected vines, costing vineyard owners as much as $65,000 per acre.
