Properties of cherry ring mottle, a distinctive strain of prune dwarf virus.

Abstract

SUMMARYA virus was transmitted from sweet cherry trees with cherry ring mottle disease to cucurbitaceous plants with the aid of liquid nitrogen, caffeine or polyethylene glycol, which were more effective than sodium diethyldithiocarbamate, polyvinylpyrrolidone and other materials used in sap‐transmission studies. The virus was transmitted from dormant buds, petals, young leaves, anthers and pollen. Of 172 herbaceous species and varieties tested, twenty‐five (thirteen spp.) became infected with virus. Ribes nigrum and peach seedlings were also infected. Of the systems produced in woody plants, those in Italian Prune resembled the symptoms caused by prune dwarf virus, but those in other Prunus spp. did not. In cucumber extracts the thermal inactivation point was between 40 and 44 d̀C; dilution end‐point was 1/16 to 1/32 and longevity in vitro 8–16 h. Formaldehyde (4%) fixed the particles and preserved their shape for electron microscopy; they were spherical, with a mean diameter of 24 nm. The virus reacted with prune dwarf virus antiserum but differed in several ways from other isolates