TREATMENTS THAT IMPROVE MECHANICAL TRANSMISSION OF CHRYSANTHEMUM CHLOROTIC MOTTLE VIRUS
Mechanical transmission of ChCMV is accomplished only with difficulty and results are not uniformly reproducible. Efficiency of transmission by rubbing with Carborundum is increased by grinding infected tissue in a chilled mortar in the presence of cold water containing 1% bentonite (1 ml diluent/g tissue) and by immediately inoculating test plants (Kryczynski et al., 1971). We have no evidence that difficulty in transmission is due to presence of inhibitors in chrysanthemum. The instability of ChCMV is quite apparent since in crude juice it survives only an hour or two at room temperature and no longer than 4 hr at near 0°C. Studies were initiated to examine the effect of additives on virus stability and to improve the reliability of mechanical inoculations by the conventional rubbing method.