Abstract
This paper reports the experimental results on the transmission of potato leaf roll virus by three species of aphids.
Virus-free, apterous, adult Myzus persicae Sulz. fed on plants infected with potato leaf roll virus for more than 3 days, transmitted the virus to 50-90per cent of healthy seedlings of Physalis floridana Rydb. when the aphids were tested individually. Rate of transmission was enhanced by increasing the number of the aphid during test feeding. The P. floridana plant infected for two weeks seems to be sufficient as a source of the virus.
In order to determine the effect of temperature on the infection, P. floridana plants were inoculated and kept at 18° and 13°C for one month. The plants produced symptoms at 18°C but no symptom was observed at 13°C with the exception of one test plant which developed symptoms 10 days after transferring to greenhouse.
The transmission rate by both aphid vectors Aulacorthum matsumuraeanum Hori and Macrosiphum euphorbiae Thom. was 10 to 20per cent when the aphids were tested individually, indicating that both species were inefficient as the vector as compared with M. persicae.
