Learn the comparison between virusoids and satellites. In 1981 for the first time J.W. Randles and coworkers discovered the virusoids. These are the small circular RNAs which are similar to viroids but they are always linked with larger molecules of the viral RNA. Robertson (1983) have reported that virusoids are essential for replication of the large RNA and, therefore, form [...]
The following points highlight the eight modes of transmission of plant viruses. The modes are: 1. Mechanical Transmission 2. Vegetative and Graft Transmission 3. Pollen Transmission 4. Seed Transmission 5. Nematode Transmission 6. Fungal Transmission 7. Insect Vector Transmission 8. Dodder Transmission. Mode # 1. Mechanical Transmission: In nature plant viruses are mechanically transmitted from diseased to healthy plants by [...]
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 [...]