Chapter 24 - Transmission of plant viruses in fields through various vectors

Abstract

The majority of the viruses causing disease in plants are transmitted from infected to healthy plants through insect vectors. Although the relationship between plant viruses and their insect vectors vary in duration and specificity, some common specific characters are observed in all vectors. These include encoding structural proteins on the surface of the virion, the which is essential for transmission of plant viruses by the insect vector. Also, some viruses have additional nonstructural helper proteins, which act as a bridge for binding virions in the vector site. Virus particles attach to specific sites in vectors and are retained at the site of binding until they are transmitted to their plant hosts. In this chapter, we discuss the transmission of viruses by various means. We focus on noninsect and insect transmission of plant viruses and the relationship between insect vectors and plant viruses. Well-described insect-vector–transmitted viruses belong to different genera, such as Caulimovirus, Crinivirus, Luteovirus, Geminiviridae, Reovirus, Tospovirus, and Tenuivirus. Virus transmission in nature takes place through fungi, nematodes, aphids, leafhoppers, planthoppers, mites, whiteflies, beetles, nematodes, and so forth, which all play an important role in the development of management strategies to break the transmission cycle.