ISOLATION OF A NEW RING SPOT VIRUS FROM PRUNUS SPECIES

In testing mother trees of sweet cherry and sour cherry a new ILAR virus belonging to the group ringspot virus was isolated. The virus is mechanically transmissible to several Nicotiana species (but the symptoms induced on these differ from those of other ring spot viruses), to Tithonia speciosa, Celosia argente a and Zinniaelegans, The thermal inactivation point of this virus is 42-44°C, dilution end point in cucumber sap 10^-2- 10^-3; stability in vitro 26–30 hours. Morphologically the virus belongs to the group isometric with a diameter of 20 mμ. Serologically it did not show relationship whith any ring spot viruses.