Tomato bushy stunt virus particles have previously been physically and chemically well characterized. Different strains, however, are known to have different host plants and symptoms, and they can be distinguished serologically. In an attempt to correlate this behavior with physicochemical properties, we have performed a comparative study on isolates of four of the main variants of this virus (Type strain, petunia asteroid mosaic virus, pelargonium leaf curl virus, and carnation Italian ringspot virus) with regard to sedimentation velocity characteristics, translational diffusivity ( from quasi-elastic light scattering measurements), and molecular weight (from both low-speed sedimentation equilibrium and the Svedberg equation).
It is demonstrated that there are no clear differences between the four strains, particularly insofar as their sedimentation characteristics (both velocity and low-speed equilibrium ) .
There is some suggestion from diffusion measurements that the Type strain virus particles may have a higher mass, although the presence of some aggregation phenomena may provide an alternative explanation for the diffusion data.