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Nerine Latent Virus
''Nerine latent virus'' (NeLV) is a plant pathogenic virus. It infects ''Nerine'', ''Narcissus'', ''Hippeastrum'' and ''Ismene'' plants. Taxonomy NeLV was first described in 1972. In 2004 it was placed in the ''Carlavirus'' genus within the family '' Flexiviridae''. When that family was split in 2009, ''Carlavirus'' and NeLV were placed in the family ''Betaflexiviridae''. Narcissus symptomless virus ''Narcissus symptomless virus'' was described as a separate virus taxon in 2006. Subsequently, in 2016 it became apparent that the nucleotide sequence identities between ''Narcissus symptomless virus'' and the partial genome sequences of Nerine latent virus are 94-97% for coat protein and replicase, well above the threshold 72% set for speciation of flexiviruses. Consequently, these two viruses can be considered to be the same taxon, and since NeLV has priority, ''Narcissus symptomless virus'' should be reduced to a synonym A synonym is a word, morpheme, or phrase that mea ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nerine
''Nerine'' (nerines, Guernsey lily, Jersey lily, spider lily) is a genus of flowering plants belonging to the family (biology), family Amaryllidaceae, subfamily Amaryllidoideae. They are bulbous perennial plant, perennials, some evergreen, associated with rocky and arid habitats. They bear spherical umbels of lily-like flowers in shades from white through pink to crimson. In the case of deciduous species, the flowers may appear on naked stems before the leaves develop. native plant, Native to South Africa, there are about 20–30 species in the genus. Though described as lilies, they are not significantly related to the true lilies (Liliaceae), but more closely resemble their relatives, ''Amaryllis'' and ''Lycoris (plant), Lycoris''. The genus was established by the Revd. William Herbert (botanist), William Herbert in 1820. Nerines have been widely cultivated and much Hybrid (biology)#Hybrid plants, hybridized worldwide, especially ''Nerine bowdenii'', ''Nerine masoniorum, N. m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Narcissus (plant)
''Narcissus'' is a genus of predominantly spring flowering perennial plant, perennial plants of the amaryllis family, Amaryllidaceae. Various common names including daffodil,The word "daffodil" is also applied to related genera such as ''Sternbergia'', ''Ismene (plant), Ismene'' and ''Fritillaria meleagris''. It has been suggested that the word "Daffodil" be restricted to the wild species of the British Isles, ''N. pseudonarcissus''. narcissus, and jonquil are used to describe all or some members of the genus. ''Narcissus'' has conspicuous flowers with six petal-like tepals surmounted by a cup- or trumpet-shaped Corona (plant structure), corona. The flowers are generally white and yellow (also orange or pink in garden varieties), with either uniform or contrasting coloured tepals and corona. ''Narcissus'' were well known in ancient civilisation, both medicinally and botanically, but formally described by Carl Linnaeus, Linnaeus in his ''Species Plantarum'' (1753). The genus ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hippeastrum
''Hippeastrum'' () is a genus of about 90 species and over 600 hybrids and cultivars of perennial herbaceous bulbous plants. They generally have large fleshy bulbs and tall broad leaves, generally evergreen, and large red or purple flowers. ''Hippeastrum'' is a genus in the family Amaryllidaceae (subfamily Amaryllidoideae, tribe Hippeastreae, and subtribe Hippeastrineae). The name ''Hippeastrum'', given to it by William Herbert, means "knight's star", although precisely what Herbert meant by the name is not certain. For many years there was confusion among botanists over the generic names ''Amaryllis'' and ''Hippeastrum'', one result of which is that the common name amaryllis is mainly used for cultivars of this genus, often sold as indoor flowering bulbs particularly at Christmas in the northern hemisphere. By contrast the generic name ''Amaryllis'' applies to bulbs from South Africa, usually grown outdoors. The genus is native to tropical and subtropical regions of the A ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ismene (plant)
''Ismene'', or Peruvian daffodil, is a genus of South American plants in the Amaryllis family. The species are native to Peru and Ecuador and widely cultivated elsewhere as ornamentals because of their large, showy flowers. ''Ismene'' produces tender perennial bulbs bearing a strong resemblance to those of ''Hymenocallis'', a genus into which ''Ismene'' had often been grouped in the past. However, its morphology differs from ''Hymenocallis'' in several significant ways: its vegetative parts, natural range, and chromosome number are all distinct. ''Ismene'' can be difficult to grow in the United States.Howard, Thad M. ''Bulbs for Warm Climates''. Austin, Texas: University of Texas Press, 2001, pp 98–99. Species A list of ''Ismene'' species and their geographic distribution is given below. *'' Ismene amancaes'' (Ruiz & Pav.) Herb – western Peru *'' Ismene hawkesii'' (Vargas) Gereau & Meerow – Cusco, Peru *'' Ismene longipetala'' (Lindl.) Meerow – southwestern Ecuador, no ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Carlavirus
''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 53 species in this genus. Diseases associated with this genus include: mosaic and ringspot symptoms. Description ''Carlavirus'' is described in the 9th report of the ICTV (2009). The genus is characterised by having six ORFs (open reading frames) including a TGB ( Triple Gene Block). The viruses are transmitted by insects. Taxonomy The genus was first proposed in the first report of the ICTV in 1971, as the 'Carnation latent virus group' but was renamed in 1975 as the 'Carlavirus group', and as the genus ''Carlavirus'' in 1995 (6th report). In 2005 (8th report) it was placed in the '' Flexiviridae'' family, having previously been unassigned. The current position in the 9th report (2009) as a genus of the family ''Betaflexiviridae'' derives from the subsequent subdivision of ''Flexivi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Flexiviridae
''Flexiviridae'' was a family of viruses named after being filamentous and highly flexible. Members of the family infect plants. In 2009, the family was dissolved and replaced with four families, each of which still contain the name ''flexiviridae'': *''Alphaflexiviridae'' *''Betaflexiviridae'' *'' Gammaflexiviridae'' *'' Deltaflexiviridae'' ''Flexiviridae'' was ''incertae sedis'' but the new families are in ''Tymovirales ''Tymovirales'' is an order of viruses with five families. The group consists of viruses which have positive-sense, single-stranded RNA genomes. Their genetic material is protected by a special coat protein. Description Tymoviruses are mainly ...''. References {{Taxonbar, from=Q3813094 Obsolete virus taxa Unaccepted virus taxa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Betaflexiviridae
''Betaflexiviridae'' is a family of viruses in the order ''Tymovirales''. Plants and fungi serve as natural hosts. There are 108 species in this family, assigned to 13 genera in two subfamilies. Diseases associated with this family include mosaic and ringspot symptoms. Taxonomy The following subfamilies and genera are recognized: * '' Quinvirinae'' ** ''Carlavirus'' ** '' Foveavirus'' ** '' Robigovirus'' ** Plus three unassigned species: *** '' Banana mild mosaic virus'' *** ''Banana virus X'' *** ''Sugarcane striate mosaic-associated virus'' * '' Trivirinae'' ** '' Capillovirus'' ** '' Chordovirus'' ** ''Citrivirus'' ** '' Divavirus'' ** '' Prunevirus'' ** '' Ravavirus'' ** '' Tepovirus'' ** ''Trichovirus ''Trichovirus'' is a genus of viruses in the order ''Tymovirales'', in the family ''Betaflexiviridae''. Plants, specifically angiosperms such as pome fruits, citrus, and pear, serve as natural hosts for this plant pathogen. There are seven spe ...'' ** '' Vitivirus'' ** ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Taxon
In biology, a taxon (back-formation from ''taxonomy''; plural taxa) is a group of one or more populations of an organism or organisms seen by taxonomists to form a unit. Although neither is required, a taxon is usually known by a particular name and given a particular ranking, especially if and when it is accepted or becomes established. It is very common, however, for taxonomists to remain at odds over what belongs to a taxon and the criteria used for inclusion. If a taxon is given a formal scientific name, its use is then governed by one of the nomenclature codes specifying which scientific name is correct for a particular grouping. Initial attempts at classifying and ordering organisms (plants and animals) were set forth in Carl Linnaeus's Linnaean taxonomy, system in ''Systema Naturae'', 10th edition (1758), as well as an unpublished work by Bernard de Jussieu, Bernard and Antoine Laurent de Jussieu. The idea of a unit-based system of biological classification was first mad ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Viral Coat Protein
A capsid is the protein shell of a virus, enclosing its genetic material. It consists of several oligomeric (repeating) structural subunits made of protein called protomers. The observable 3-dimensional morphological subunits, which may or may not correspond to individual proteins, are called capsomeres. The proteins making up the capsid are called capsid proteins or viral coat proteins (VCP). The capsid and inner genome is called the nucleocapsid. Capsids are broadly classified according to their structure. The majority of the viruses have capsids with either helical or icosahedral structure. Some viruses, such as bacteriophages, have developed more complicated structures due to constraints of elasticity and electrostatics. The icosahedral shape, which has 20 equilateral triangular faces, approximates a sphere, while the helical shape resembles the shape of a spring, taking the space of a cylinder but not being a cylinder itself. The capsid faces may consist of one or more ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Replicase
RNA-dependent RNA polymerase (RdRp) or RNA replicase is an enzyme that catalyzes the replication of RNA from an RNA template. Specifically, it catalyzes synthesis of the RNA strand complementary to a given RNA template. This is in contrast to typical DNA-dependent RNA polymerases, which all organisms use to catalyze the transcription of RNA from a DNA template. RdRp is an essential protein encoded in the genomes of most RNA-containing viruses with no DNA stage including SARS-CoV-2. Some eukaryotes also contain RdRps, which are involved in RNA interference and differ structurally from viral RdRps. History Viral RdRps were discovered in the early 1960s from studies on mengovirus and polio virus when it was observed that these viruses were not sensitive to actinomycin D, a drug that inhibits cellular DNA-directed RNA synthesis. This lack of sensitivity suggested that there is a virus-specific enzyme that could copy RNA from an RNA template and not from a DNA template. D ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Speciation
Speciation is the evolutionary process by which populations evolve to become distinct species. The biologist Orator F. Cook coined the term in 1906 for cladogenesis, the splitting of lineages, as opposed to anagenesis, phyletic evolution within lineages. Charles Darwin was the first to describe the role of natural selection in speciation in his 1859 book ''On the Origin of Species''. He also identified sexual selection as a likely mechanism, but found it problematic. There are four geographic modes of speciation in nature, based on the extent to which speciating populations are isolated from one another: allopatric speciation, allopatric, peripatric speciation, peripatric, parapatric speciation, parapatric, and sympatric speciation, sympatric. Speciation may also be induced artificially, through animal husbandry, agriculture, or laboratory experiments of speciation, laboratory experiments. Whether genetic drift is a minor or major contributor to speciation is the subject of much ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Flexiviruses
''Tymovirales'' is an order of viruses with five families. The group consists of viruses which have positive-sense, single-stranded RNA genomes. Their genetic material is protected by a special coat protein. Description Tymoviruses are mainly plant pathogens first described in 2004. They are characterised by similarities in their replication-associated polyproteins. These account for the majority of their genomic coding capacity. They are considered to form a group, phylogenetically, referred to as flexiviruses, with filamentous virions A virus is a submicroscopic infectious agent that replicates only inside the living cells of an organism. Viruses infect all life forms, from animals and plants to microorganisms, including bacteria and archaea. Since Dmitri Ivanovsky's 1 .... References Bibliography * External links ICTV Virus Taxonomy 2009 UniProt Taxonomy {{Use dmy dates, date=April 2017 Virus orders Riboviria ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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