Abstract
1. This paper deals with serological experiments using the radish R and P virus. Radish R virus used as the immunizing antigen was the isolate “Miyahara 5”, which was obtained from a mosaic radish plant collected at Miyahara, Saitama Prefecture, November 1958, passed through tobacco and broad bean local lesions, and maintained by successive juice inoculations on turnip plants in a greenhouse. The radish P virus and the P antiserum used were the isolate Po, and the Po antiserum, reported previously. (Ann. Phytopath. Soc. Japan, 24)
2. By treating with chloroform, salting-out with ammonium sulfate, and differential centrifugation, a partially purified R virus preparation was obtained from infected turnip leaf juice. Antiserum was prepared by injecting rabbits with this virus preparation. The rabbits were given 6 intravenous injections (equivalent to total leaf juice volume of 250ml per rabbit), at 2-7 days intervals. The titer of the antiserum obtaind was 1:5120 in precipitation reaction. The antiserum did not react with leaf juice from healthy turnip plants.
3. Dilution end point was 1:32 in precipitation reaction with R virus, using infected turnip leaf juice. Reaction was, however, not detectable in agglutination reaction on slides.
4. The R antiserum reacted with leaf juice of turnip infected either with the radish R virus or P virus. In absorption tests, the R antiserum completely absorbed the radish R virus and P virus. Results with the P antiserum was almost the same. In precipitation reaction with either R antiserum or P antiserum, R virus always produced dense granular precipitates, while P virus always produced bulky and flocculent precipitates.
5. There was found only a slight difference in antigen-structure between R virus and P virus, as revealed in precipitation reaction, using infected turnip leaf juice.
