Maize streak virus MSV is an insect transmitted maize pathogen in the genus Mastrevirus of the family Geminiviridae that is endemic epidemiology endemic in sub Saharan Africa. The A strain of MSV MSV A causes sporadic maize streak disease epidemics throughout the maize growing regions of Africa ref citation doi 10.1111 j.1364 3703.2009.00568.x title Maize streak virus an old and complex emerging pathogen year 2009 author Dionne N Shepherd, Darren P Martin, Eric Van Der Walt, Kyle Dent, Arvind Varsani, Ed Rybicki journal Molecular Plant Pathology volume 11 pages 1 12 ref ref citation doi 10.1007 s12571 009 0023 1 title The epidemiology, economic impact and control of maize streak disease year 2009 author Darren P. Martin and Dionne N. Shepherd journal Food Security volume 1 pages 305 315 ref ref citation doi 10.1016 S0168 1702 00 00192 1 title Eight decades of maize streak virus research year 2000 author Nilsa A. Bosque P rez journal Virus Research volume 71 pages 107 121 ref . MSV was first described by the South African entomologist Claude Fuller entomologist Claude Fuller who referred to it in a 1901 report as mealie variegation ref http www.mediaclubsouthafrica.com index.php?option com content&view article&id 2027 gmo 271010&catid 48 innovationnews&Itemid 115 ref . The development of conventionally resistant maize varieties has been a priority since the 1950s in Kenya, Nigeria, South Africa and elsewhere, with a good deal of success however, there are several genes associated with resistance, and breeding is complex. Transgenically resistant or genetically modified crop genetically modified maize varieties are currently under development in South Africa ref citation doi 10.1111 j.1467 7652.2007.00279.x title Maize streak virus resistant transgenic maize a first for Africa year 2007 author Dionne N. Shepherd, Tichaona Mangwende, Darren P. Martin, Marion Bezuidenhout, Frederik J. Kloppers, Charlene H. Carolissen, Ad rito L. Monjane, Edward P. Rybicki, and Jennifer ... more details
infect animal s mammal s and bird s respectively and the Geminiviridae and Nanoviridae infect plant s. In both the Geminiviridae and Nanoviridae the genome is composed of more than a single ... Circoviridae Family Geminiviridae Family Inoviridae Family Microviridae Family Nanoviridae Family ... 18 8387 8392 ref This virus appears to be related to the Geminiviridae but is distinct from them. An unusual ... more details
Taxobox image Weisse Fliege.jpg image caption Whiteflies Trialeurodes vaporariorum regnum Animal ia phylum Arthropoda classis Insecta ordo Homoptera subordo Sternorrhyncha superfamilia Aleyrodoidea familia Aleyrodidae subdivision ranks Subfamilies ref Martin, J.H. & Mound, L.A. An annotated check list of the world s whiteflies Insecta Hemiptera Aleyrodidae . Zootaxa 1492 2007 1 84. ref subdivision Aleurodicinae br Aleyrodinae br Udamoselinae The whiteflies , comprising only the family Aleyrodidae , are small hemiptera ns. More than List of whitefly species 1550 species have been described. Whiteflies typically feed on the underside of plant leaves. Agricultural threat The ability of the whitefly to carry and spread disease is the widest impact they have had on global food production. In the tropics and subtropics, whiteflies have become one of the most serious crop protection problems. Economic losses are estimated in the hundreds of millions of dollars. While several species of whitefly cause crop losses through direct feeding, a species complex, or group of whiteflies in the genus Bemisia are important in the transmission of plant diseases. Bemisia tabaci and B. argentifolii , transmit African cassava mosaic virus African cassava mosaic , bean golden mosaic, bean dwarf mosaic, bean calico mosaic, Tomato yellow leaf curl virus tomato yellow leaf curl , tomato mottle, and other Begomovirus es, in the Family Geminiviridae . The worldwide spread of emerging biotypes, such as B. tabaci biotype B, also known as, B. argentifolii , and a new biotype Q, continue to cause severe crop losses which will likely continue to increase, resulting in higher pesticide use on many crops tomatoes, beans, cassava, cotton, cucurbits, potatoes, sweet potatoes . Efforts to develop environmentally friendly integrated pest management systems, with the goal of reducing insecticide use aim to re establish the ecological equilibrium of predator s, parasitoid s, and microbial controls that were ... more details
File 19th century print rinderpest.jpg right thumb A Japanese print from the 19th century depicting the burning of cattle infected with rinderpest The recorded history of viruses begins in the closing years of the 19th century, but viruses are as old as life on Earth. The most abundant biological entity on Earth, they Infection infect organisms in all Three domain system three domains of life although their origins are uncertain, they may pre date the emergence of cell biology cells . Viruses have evolution evolved to become the most successful of parasitism parasites and have infected plants and animals, including humans, for millions of years. Many infectious diseases were known to be caused by bacteria and other microorganism s, but no cause could be found for others such as smallpox , which had been recognised for more than a thousand years. Epidemic s caused by viruses began when human behaviour changed during the Neolithic period . Previously hunter gatherer s, humans developed relatively densely populated agricultural communities, which allowed viruses to spread rapidly and subsequently to become endemic epidemiology endemic . Despite having no idea that viruses existed, Louis Pasteur and Edward Jenner were the first to develop vaccine s to protect against viral infections. Viruses were not discovered until the early 20th century, when the science of virology the study of viruses and the diseases they cause began. In the 20th century many old and new diseases were discovered to be caused by viruses. Although scientific interest in them arose because of the diseases they cause, most viruses are beneficial. They have driven evolution by horizontal gene transfer transferring genes across species, play important roles in ecosystem s, and are essential to life. TOC limit 3 Origins Viruses are ancient. Studies at the molecular level have revealed relationships between viruses infecting organisms from each of the three domain theory three domains of life , and viral ... more details
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