|
Tobacco Ringspot Virus
''Tobacco ringspot virus'' (TRSV) is a plant pathogenic virus in the plant virus family ''Secoviridae''. It is the type species of the genus ''Nepovirus''. Nepoviruses are transmitted between plants by nematodes, thrips, mites, grasshoppers, and flea beetles. TRSV is also easily transmitted by sap inoculation and transmission in seeds has been reported. In recent cases it has also been shown to appear in bees, but no transmission to plants from bees has been noted. TRSV was observed for the first time in tobacco fields in Virginia and described in 1927. It is an isometric particle with a bipartite RNA genome. The virus has a wide host range that includes field grown crops, ornamentals and weeds. Its name comes from its most common symptom being chlorotic ringspots on the leaves of infected plants. In some areas this virus has caused growers to stop growing affected crops. A. B. C. Symptoms and virus inclusions of Tobacco ringspot nepovirus in the host ''Zamia furfuracea'', th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Plant Virus
Plant viruses are viruses that affect plants. Like all other viruses, plant viruses are obligate intracellular parasites that do not have the molecular machinery to replicate without a host. Plant viruses can be pathogenic to higher plants. Most plant viruses are rod-shaped, with protein discs forming a tube surrounding the viral genome; isometric particles are another common structure. They rarely have an envelope. The great majority have an RNA genome, which is usually small and single stranded (ss), but some viruses have double-stranded (ds) RNA, ssDNA or dsDNA genomes. Although plant viruses are not as well understood as their animal counterparts, one plant virus has become very recognizable: ''tobacco mosaic virus'' (TMV), the first virus to be discovered. This and other viruses cause an estimated US$60 billion loss in crop yields worldwide each year. Plant viruses are grouped into 73 genera and 49 families. However, these figures relate only to cultivated plants, which r ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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''. Taxonomy The family includes the following genera (-''virinae'' denotes subfamily and -''virus'' denotes genus): * ''Comovirinae ''Comovirinae'' is a subfamily of viruses in the order ''Picornavirales'', in the family ''Secoviridae''; its genera were formerly classified in the family ''Comoviridae''. Plants serve as natural hosts. There are 62 species in this subfamily, a ...'' ** '' Comovirus'' ** '' Fabavirus'' ** '' Nepovirus'' * Unassigned to a subfamily: ** '' Cheravirus'' ** '' Sadwavirus'' ** '' Sequivirus'' ** '' Torradovirus'' ** '' Waikavirus'' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nepovirus
''Nepovirus'' is a genus of viruses in the order ''Picornavirales'', in the family ''Secoviridae'', in the subfamily ''Comovirinae''. Plants serve as natural hosts. There are 40 species in this genus. Nepoviruses, unlike the other two genera (''Comovirus'' and ''Fabavirus'') in the subfamily ''Comovirinae'', are transmitted by nematodes. Taxonomy The genus contains the following species: *'' Aeonium ringspot virus'' *'' Apricot latent ringspot virus'' *'' Arabis mosaic virus'' *'' Arracacha virus A'' *'' Artichoke Aegean ringspot virus'' *'' Artichoke Italian latent virus'' *'' Artichoke yellow ringspot virus'' *'' Beet ringspot virus'' *'' Blackcurrant reversion virus'' *'' Blueberry latent spherical virus'' *'' Blueberry leaf mottle virus'' *'' Cassava American latent virus'' *'' Cassava green mottle virus'' *'' Cherry leaf roll virus'' *'' Chicory yellow mottle virus'' *'' Cocoa necrosis virus'' *'' Crimson clover latent virus'' *'' Cycas necrotic stunt virus'' *'' Grapevin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nematodes
The nematodes ( or grc-gre, Νηματώδη; la, Nematoda) or roundworms constitute the phylum Nematoda (also called Nemathelminthes), with plant-parasitic nematodes also known as eelworms. They are a diverse animal phylum inhabiting a broad range of environments. Less formally, they are categorized as Helminths, but are taxonomically classified along with arthropods, tardigrades and other moulting animals in the clade Ecdysozoa, and unlike flatworms, have tubular digestive systems with openings at both ends. Like tardigrades, they have a reduced number of Hox genes, but their sister phylum Nematomorpha has kept the ancestral protostome Hox genotype, which shows that the reduction has occurred within the nematode phylum. Nematode species can be difficult to distinguish from one another. Consequently, estimates of the number of nematode species described to date vary by author and may change rapidly over time. A 2013 survey of animal biodiversity published in the mega jo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Inoculation
Inoculation is the act of implanting a pathogen or other microorganism. It may refer to methods of artificially inducing immunity against various infectious diseases, or it may be used to describe the spreading of disease, as in "self-inoculation," the spreading of disease from one part of the body to another, or even to the spreading of bacteria in a Petri dish for culturing purposes. The terms "inoculation", "vaccination", and "immunization" are often used synonymously, but there are some important differences among them. Inoculation is the act of implanting a disease inside a person or animal, vaccination is the act of implanting or giving someone a vaccine specifically, and immunization is what happens to the immune system as a result. Terminology Until the early 1800s inoculation referred only to variolation (from the Latin word ''variola'' = smallpox), the predecessor to the smallpox vaccine. The smallpox vaccine, introduced by Edward Jenner in 1796, was called cowpox inoc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tobacco Ringspot Virus
''Tobacco ringspot virus'' (TRSV) is a plant pathogenic virus in the plant virus family ''Secoviridae''. It is the type species of the genus ''Nepovirus''. Nepoviruses are transmitted between plants by nematodes, thrips, mites, grasshoppers, and flea beetles. TRSV is also easily transmitted by sap inoculation and transmission in seeds has been reported. In recent cases it has also been shown to appear in bees, but no transmission to plants from bees has been noted. TRSV was observed for the first time in tobacco fields in Virginia and described in 1927. It is an isometric particle with a bipartite RNA genome. The virus has a wide host range that includes field grown crops, ornamentals and weeds. Its name comes from its most common symptom being chlorotic ringspots on the leaves of infected plants. In some areas this virus has caused growers to stop growing affected crops. A. B. C. Symptoms and virus inclusions of Tobacco ringspot nepovirus in the host ''Zamia furfuracea'', th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Zamia
''Zamia'' is a genus of cycad of the family Zamiaceae, native to North America from the United States (in Georgia and Florida) throughout the West Indies, Central America, and South America as far south as Bolivia. The genus is considered to be the most ecologically and morphologically diverse cycads, and is estimated to have originated about 68.3 million years ago. Description The genus comprises deciduous shrubs with aerial or subterranean circular stems, often superficially resembling palms. They produce spirally arranged, pinnate leaves which are pubescent, at least when young, having branched and simple, transparent and coloured hairs. The articulated leaflets lack a midrib, and are broad with subparallel dichotomous venation. Lower leaflets are not reduced to spines, though the petioles often have prickles. The emerging leaves of many ''Zamia'' species are striking, some emerging with a reddish or bronze cast ('' Z. roeslii'' being an example). ''Zamia picta'' is even more ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cycad
Cycads are seed plants that typically have a stout and woody (ligneous) trunk (botany), trunk with a crown (botany), crown of large, hard, stiff, evergreen and (usually) pinnate leaves. The species are dioecious, that is, individual plants of a species are either male or female. Cycads vary in size from having trunks only a few centimeters to several meters tall. They typically grow very slowly and live very long. Because of their superficial resemblance, they are sometimes mistaken for Arecaceae, palms or ferns, but they are not closely related to either group. Cycads are gymnosperms (naked-seeded), meaning their fertilization, unfertilized seeds are open to the air to be directly fertilized by pollination, as contrasted with angiosperms, which have enclosed seeds with more complex fertilization arrangements. Cycads have very specialized pollinators, usually a specific species of beetle. Both male and female cycads bear cones (strobilus, strobili), somewhat similar to conife ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Viral Diseases Of Potato
Viral diseases of potato are a group of diseases caused by different types of viruses that affect potato crops worldwide and, although they do not affect human or animal health since they are viruses that only infect vegetables, they are a source of great economic losses annually. About 28 viruses have been reported infecting potato crops. However, potato virus X ( PVX), potato virus Y ( PVY), and potato leafroll virus ( PLRV) are the most important viruses worldwide. Some others are of economic importance only in some regions. Such is the case of potato virus M (PVM) in some Asian and European countries. An additional problem is the co-infection of two or more viruses on the same plants. In fact, the joint occurrence of PVX and PVY, or either or both of them with PLRV or Potato virus A ( PVA), produces much more severe symptoms than separate infection of each. The magnitude of economic losses associated with this synergistic effect depends on the types of viruses that are intera ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nepoviruses
''Nepovirus'' is a genus of viruses in the order ''Picornavirales'', in the family ''Secoviridae'', in the subfamily ''Comovirinae''. Plants serve as natural hosts. There are 40 species in this genus. Nepoviruses, unlike the other two genera (''Comovirus'' and ''Fabavirus'') in the subfamily ''Comovirinae'', are transmitted by nematodes. Taxonomy The genus contains the following species: *'' Aeonium ringspot virus'' *'' Apricot latent ringspot virus'' *'' Arabis mosaic virus'' *'' Arracacha virus A'' *'' Artichoke Aegean ringspot virus'' *'' Artichoke Italian latent virus'' *'' Artichoke yellow ringspot virus'' *'' Beet ringspot virus'' *'' Blackcurrant reversion virus'' *'' Blueberry latent spherical virus'' *'' Blueberry leaf mottle virus'' *'' Cassava American latent virus'' *'' Cassava green mottle virus'' *'' Cherry leaf roll virus'' *'' Chicory yellow mottle virus'' *'' Cocoa necrosis virus'' *'' Crimson clover latent virus'' *'' Cycas necrotic stunt virus'' *'' Grapevin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
.jpg "Click for more on -> Cycad")
.jpg "Click for more on -> Viral Diseases Of Potato")