STUDIES ON THE MECHANISM OF APHID TRANSMISSION OF MOSAIC DISEASE OF JAPANESE RADISH USING RADIOACTIVE PHOSPHORUS 32

Abstract

The present paper deals with the results of the studies carried out under 15° to 20°C, on the mechanism of aphid (Myzus persicae Sulz.) transmission of mosaic disease of Japanese radish using radioactive phosphorus 32.
1) Aphids were fed for 5 (Table 3) and 10 minutes (Table 1) each on the virus diseased Japanese radish (Raphanus sativus L.) seedling which had been cultured with the solution containing radioactive phosphorus 32 (200μc/ml). They were then transferred to each of 10 healthy radish seedlings successively and fed for 5 and 10 minutes respectively. Results showed that aphids could transmit the virus disease up to the 6th seedling, while all of 10 seedlings on which aphids were fed were found to be radioactive when determined by autoradiography.
2) Aphids fed for 10 minutes (Table 2), 1 minute (Table 4), and 30 seconds (Table 5) respectively on the diseased radish seedling containing radioactive phosphorus 32, were transferred to each of 8 to 15 healthy radish seedlings successively and fed for 1 minute or 30 seconds. Results showed that in the case of short infection feeding time such as 30 seconds or 1 minute no appreciable differences were observed between infectivity of the virus and transportation of phosphorus 32 by one aphid when 8 to 15 plants were infected successively.