ELECTRON MICROSCOPY ON IN VIVO AGGREGATION FORMS OF A STRAIN OF ALFALFA MOSAIC VIRUS

The particle length distribution of alfalfa mosaic virus (AMV) particles from crude preparations from tobacco leaves did not differ significantly from the length distribution of particles in preparations of AMV purified from tobaccos at the same stage of infection. In older infections components with particles longer than bottom component were found. Two aggregation forms of AMV particles were found in sections and in negatively stained crude preparations. One form was found only in the vacuole, and the other in the cytoplasm. The structures of the aggregates are described, and the differences between them are discussed. © 1969 Academic Press, Inc.