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 [...]
The following points highlight the life cycle of a typical plant virus such as TMV (Tobacco Mosaic Virus) which comprises of four stages. The stages are: 1. Transmission of Virus Particles (Virions) 2. Infection 3. Virus Multiplication 4. Sites of Viral RNA and Viral Protein Synthesis. Stage # 1. Transmission of Virus Particles (Virions): The rod-shaped Tobacco Mosaic Virus (TMV) [...]
In this article we will discuss about:- 1. Origin of Viroid 2. Meaning of Viroids 3. Viroid Genome 4. Replication. Origin of Viroid: So far no sufficient information is available that can lend support for the origin of viroids. Following are some of the speculations regarding the origin of viroids: (a) Viroids are supposed to be the primitive viruses and [...]