ASCOT Library Zabali Campus

Includes bibliographical references and index.

1. Introduction --
2. Emergent plant viruses --
3. Causes of plant diseases --
4. Virus structure --
5. Architecture of viruses and viroids in plant --
6. Viruses as biological control agents of insect pests --
7. Plant diseases: nature and importance --
8. Virus infection of plants --
9. Morphology of virology.

"Plant viruses cause considerable economic losses and are a threat for sustainable agriculture. The frequent emergence of new viral diseases is mainly due to international trade, climate change, and the ability of viruses for rapid evolution. Virus particles are extremely small and can be seen only with an electron microscope. Most plant viruses are either rod-shaped or isometric (polyhedral). TMV, potato virus Y (PVY), and cucumber mosaic virus (CMV) are examples of a short rigid rod-shaped, a long flexuous rod-shaped, and an isometric virus, respectively. Viruses consist of an inner core of nucleic acid (either ribonucleic acid [RNA] or deoxyribonucleic acid [DNA]) surrounded by an outer sheath or coat of protein (referred to as the capsid). The capsid is further enclosed by a membrane in most human and animal viruses that helps the virus pass through the cell membrane in these types of cells. Viruses are found wherever there is life and have probably existed since living cells first evolved. The origin of viruses is unclear because they do not form fossils, so molecular techniques have been the most useful means of investigating how they arose. These techniques rely on the availability of ancient viral DNA or RNA, but, unfortunately, most of the viruses that have been preserved and stored in laboratories are less than 90 years old. There are three main hypotheses that try to explain the origins of viruses: Viruses often overwinter in biennial and perennial crops and weeds (plants that overwinter by means of roots and produce seed in their second year or during several years, respectively), in plant debris, and in insect vectors. Plants, once infected, normally remain so for life. This book covers all the pertinent aspects of plant viruses and its historical aspects." -- Provided by publisher