This volume consists of 85 chapters that highlight recent advances in our knowledge of the viruses that infect plants and fungi. It begins with general topics in plant virology including movement of viruses in plants, the transmission of plant viruses by vectors, and the development of virus-resistant transgenic plants. The second section presents an overview of the properties of a selection of 20 well-studied plant viruses, 23 plant virus genera and a few larger groups of plant viruses. The third section, which is abundantly illustrated, highlights the most economically important virus diseases of cereals, legumes, vegetable crops, fruit trees and ornamentals. The last section describes the major groups of viruses that infect fungi.