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PVY
Potato virus Y (PVY) is a plant pathogenic virus of the family ''Potyviridae'', and one of the most important plant viruses affecting potato production. PVY infection of potato plants results in a variety of symptoms depending on the viral strain. The mildest of these symptoms is production loss, but the most detrimental is 'potato tuber necrotic ringspot disease' (PTNRD). Necrotic ringspots render potatoes unmarketable and can therefore result in a significant loss of income. PVY is transmissible by aphid vectors but may also remain dormant in seed potatoes. This means that using the same line of potato for production of seed potatoes for several consecutive generations will lead to a progressive increase in viral load and subsequent loss of crop. An increase in potato plant infection with viruses over the past few years has led to considerable losses to the South African potato industry. The increased rate of infection may be attributed to several factors. These include a mar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Potyvirus
''Potyvirus'' is a genus of positive-strand RNA viruses in the family ''Potyviridae''. Plants serve as natural hosts. The genus is named after member virus ''potato virus Y''. Potyviruses account for about thirty percent 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'' (genera ''Macrosiphum'' and ''Myzus''). The genus contains 190 species. Virology Structure The virion is non-enveloped with a flexuous and filamentous nucleocapsid, 680 to 900 nanometers (nm) long and is 11–20 nm in diameter. The nucleocapsid contains around 2000 copies of the capsid protein. The symmetry of the nucleocapsid is helical with a pitch of 3.4 nm. Genome The genome is a linear, positive-sense, single-stranded RNA ranging in size from 9,000–12,000 nucleoti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Myzus Persicae
''Myzus persicae'', known as the green peach aphid, greenfly, or the peach-potato aphid, is a small green aphid belonging to the order Hemiptera. It is the most significant aphid pest of peach trees, causing decreased growth, shrivelling of the leaves and the death of various tissues. It also acts as a vector for the transport of plant viruses such as cucumber mosaic virus (CMV), potato virus Y (PVY) and tobacco etch virus (TEV). Potato virus Y and potato leafroll virus can be passed to members of the nightshade/potato family (Solanaceae), and various mosaic viruses to many other food crops. Originally described by Swiss entomologist Johann Heinrich Sulzer in 1776, its specific name is derived from the Latin genitive ''persicae,'' "of the peach". The syntype specimen of this species is located in the Illinois Natural History Survey Insect Collection. Life cycle Life cycle of the green peach aphid varies depending on temperature. A fully completed generation takes approximately 1 ... [...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] |
Capsicum
''Capsicum'' () is a genus of flowering plants in the Solanum, nightshade family Solanaceae, native to Americas, the Americas, cultivated worldwide for their chili pepper or bell pepper fruit. Etymology and names The generic name may come from Latin language, Latin , meaning 'box', presumably alluding to the pods; or possibly from the Greek language, Greek word , 'to gulp'. The name "pepper" comes from the similarity of piquance (spiciness or "heat") of the flavor to that of black pepper, ''Piper (genus), Piper nigrum'', although there is no botanical relationship with it or with Sichuan pepper. The original term, ''chilli'' (now ''chile'' in Mexico) came from the Nahuatl word ''chīlli'', denoting a larger ''Capsicum'' variety Mesoamerican agriculture, cultivated at least since 3000 BC, as evidenced by remains found in pottery from Puebla and Oaxaca. Different varieties were cultivated in South America, where they are known as ''ajíes'' (singular ''ají''), from the Quechu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Endoplasmic Reticulum
The endoplasmic reticulum (ER) is, in essence, the transportation system of the eukaryotic cell, and has many other important functions such as protein folding. It is a type of organelle made up of two subunits – rough endoplasmic reticulum (RER), and smooth endoplasmic reticulum (SER). The endoplasmic reticulum is found in most eukaryotic cells and forms an interconnected network of flattened, membrane-enclosed sacs known as cisternae (in the RER), and tubular structures in the SER. The membranes of the ER are continuous with the outer nuclear membrane. The endoplasmic reticulum is not found in red blood cells, or spermatozoa. The two types of ER share many of the same proteins and engage in certain common activities such as the synthesis of certain lipids and cholesterol. Different types of cells contain different ratios of the two types of ER depending on the activities of the cell. RER is found mainly toward the nucleus of cell and SER towards the cell membrane or plasma ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Virion
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 1892 article describing a non-bacterial pathogen infecting tobacco plants and the discovery of the tobacco mosaic virus by Martinus Beijerinck in 1898,Dimmock p. 4 more than 9,000 virus species have been described in detail of the millions of types of viruses in the environment. Viruses are found in almost every ecosystem on Earth and are the most numerous type of biological entity. The study of viruses is known as virology, a subspeciality of microbiology. When infected, a host cell is often forced to rapidly produce thousands of copies of the original virus. When not inside an infected cell or in the process of infecting a cell, viruses exist in the form of independent particles, or ''virions'', consisting of (i) the genetic material, i.e ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sense (molecular Biology)
In molecular biology and genetics, the sense of a nucleic acid molecule, particularly of a strand of DNA or RNA, refers to the nature of the roles of the strand and its complement in specifying a sequence of amino acids. Depending on the context, sense may have slightly different meanings. For example, negative-sense strand of DNA is equivalent to the template strand, whereas the positive-sense strand is the non-template strand whose nucleotide sequence is equivalent to the sequence of the mRNA transcript. DNA sense Because of the complementary nature of base-pairing between nucleic acid polymers, a double-stranded DNA molecule will be composed of two strands with sequences that are reverse complements of each other. To help molecular biologists specifically identify each strand individually, the two strands are usually differentiated as the "sense" strand and the "antisense" strand. An individual strand of DNA is referred to as positive-sense (also positive (+) or simply sense) ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
MRNA
In molecular biology, messenger ribonucleic acid (mRNA) is a single-stranded molecule of RNA that corresponds to the genetic sequence of a gene, and is read by a ribosome in the process of Protein biosynthesis, synthesizing a protein. mRNA is created during the process of Transcription (biology), transcription, where an enzyme (RNA polymerase) converts the gene into primary transcript mRNA (also known as pre-mRNA). This pre-mRNA usually still contains introns, regions that will not go on to code for the final amino acid sequence. These are removed in the process of RNA splicing, leaving only exons, regions that will encode the protein. This exon sequence constitutes mature mRNA. Mature mRNA is then read by the ribosome, and, utilising amino acids carried by transfer RNA (tRNA), the ribosome creates the protein. This process is known as Translation (biology), translation. All of these processes form part of the central dogma of molecular biology, which describes the flow of genet ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Protein Of The Viral Capsid
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 mor ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stylet (anatomy)
A stylet is a hard, sharp, anatomical structure found in some invertebrates. For example, the word ''stylet'' or stomatostyle is used for the primitive piercing mouthparts of some nematodes and some nemerteans. In these groups the stylet is a hardened protrusible opening to the stomach. These stylets are adapted for the piercing of cell walls and usually function by providing the operative organism with access to the nutrients contained within the prey cell. The mouthparts of tardigrades, diptera and aphid Aphids are small sap-sucking insects and members of the superfamily Aphidoidea. Common names include greenfly and blackfly, although individuals within a species can vary widely in color. The group includes the fluffy white woolly aphids. A t ...s are also called stylets. In octopodes, the stylets are internal, needle-like bent rods within the mantle, the vestigial remnants of an external shell. References Nematode anatomy {{Animal-anatomy-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rhopalosiphum
''Rhopalosiphum'' is a genus of aphid of the family Aphididae that includes 16 species worldwide. Apart from sucking the phloem of host plants and thereby being treated in agriculture as pests, some species are vectors for viral pathogens. Species Species include: *'' Rhopalosiphum arundinariae'' ( A. N. Tissot, 1933) *'' Rhopalosiphum cerasifoliae'' ( Fitch, 1855) *'' Rhopalosiphum chusqueae'' (Pérez Hidalgo & Villalobos Muller, 2012) *'' Rhopalosiphum enigmae'' ( F. C. Hottes and T. H. Frison, 1931) *'' Rhopalosiphum insertum'' (Walker, 1849) - apple-grass aphid *''Rhopalosiphum maidis'' ( Fitch, 1856) - corn leaf aphid *'' Rhopalosiphum musae'' ( Schouteden, 1906) *'' Rhopalosiphum nigrum'' (Richards, 1960) *'' Rhopalosiphum nymphaeae'' (Linnaeus, 1761) - water lily or plum aphid *''Rhopalosiphum padi'' (Linnaeus, 1758) - bird cherry-oat aphid *'' Rhopalosiphum padiformis'' (Richards, 1962) *'' Rhopalosiphum parvae'' (Hottes and Frison, 1931) *''Rhopalosiphum ru ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aphis
''Aphis'' is a genus of insects in the family Aphididae containing at least 600 species of aphids. It includes many notorious agricultural pests, such as the soybean aphid '' Aphis glycines''. Many species of ''Aphis'', such as '' A. coreopsidis'' and '' A. fabae'', are myrmecophiles, forming close associations with ants. Selected Species *'' Aphis affinis'' *'' Aphis asclepiadis'' — milkweed aphid *'' Aphis craccae'' — tufted vetch aphid *''Aphis craccivora'' — cowpea aphid *''Aphis fabae'' — black bean aphid *'' Aphis genistae'' *''Aphis gossypii'' — cotton aphid *'' Aphis glycines'' — soybean aphid *'' Aphis helianthi'' — sunflower aphid *''Aphis nerii'' — oleander aphid *'' Aphis pomi'' — apple aphid *''Aphis rubicola'' — small raspberry aphid *''Aphis spiraecola'' — spirea aphid (syn. ''Aphis citricola'' — citrus aphid) *''Aphis valerianae'' — black valerian aphid See also * List of Aphis species Photos Image:Aphis citricola1.jpg, ''Aphis ci ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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