In this article we will discuss about:- 1. Historical Account of Viruses 2. General Characteristics of Viruses 3. Origin 4. Chemical Composition. Historical Account of Viruses: Some of the plant diseases, although not attributed to viruses at that time, were observed quite early. Breaking of Tulip was recorded as early as 1576 while potato curl disease and peach yellows were [...]
The following points highlight the eight chief methods used for the transmission of plant viruses. The methods are: 1. Seed Transmission of Virus 2. Transmission by Vegetative Propagation 3. Transmission by Mechanical Means 4. Transmission by Cuscuta 5. Soil Transmission 6. Insect Transmission 7. Transmission by Fungi 8. Some Soil Inhabiting Viruses have Nematode Vectors. Method # 1. Seed Transmission [...]
In this article we will discuss about the structure of reoviruses (explained with diagram). Non-enveloped, icosahedral virion with a double capsid structure (e.g. rotavirus and orthoreovirus) where iuter capsid has an icosahedral T=13 symmetry, and inner capsid an icosahedral 7=2 symmetry. The outer capsid is positioned upon the virion in such a way that the capsomeres of each capsid layer [...]