ABSTRACT
This chapter provides a brief account of the development of studies on structure, composition, properties, cytopathology, and taxonomy of alfalfa mosaic virus (AMV). AMV has close affinities with the Ilarvirus group and is perhaps more distantly related to the Bromoviruses and Cucumoviruses. A higher taxon such as the proposed family Tricornaviridae to include all four groups may eventually be approved. Electron micrographs of AMV preparations reveal a variety of particles ranging from polyhedra about 18 nm in diameter to bacilliform structures of the same diameter but various lengths. A number of authors have observed AMV particles in thin sections in the cytoplasm of infected plant cells. All the observations indicate that in cells of fully infected leaves, masses of AMV particles accumulate in the cytoplasm. Several pseudorecombinants between naturally occurring AMV strains, and artifically induced mutants have been constructed in vitro and inoculated to plants to determine the genetic information carried by the genomic components.
