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 [...]
In this article we will discuss about the external and internal symptoms that affect the viruses on plants. Since viruses are the obligate parasites, they impart several external and internal symptoms on host plants. 1. External Symptoms: There is a variety of external symptoms that appear on infected plants. Some of the most common symptoms are described below: (i) Mosaic: [...]
In this article we will discuss about the structure of adenoviruses (explained with diagram). All adenovirus particles are similar; particles are medium-sized, non-enveloped having 90-100 nm diameters (Fig. 17.5). The particles have icosahedral symmetry which can easily be visible in the electron microscope by negative staining. Viral particles are composed of 252 capsomers: 240 hexons forming the faces and 12 [...]