Comparative cytology of nine isolates of cauliflower mosaic virus

The cytology of nine isolates of cauliflower mosaic virus was compared by light and electron microscopy. Differences noted among the isolates were: the size of cytoplasmic inclusion bodies, frequency of virions occurring free in the cytoplasm as opposed to those in inclusions, the ratio of virions to the amount of matrix protein in inclusions, and intraplastidial inclusions induced by one of the isolates. It was concluded that these four cytological features are expressions of the viral genome rather than the host. One of the isolates induced different sized inclusions in two different hosts.