Transmission studies on an indian isolate of sugarcane mosaic potyvirus

Abstract

An Indian isolate of sugarcane mosaic virus was found easily transmitted by mechanical sap inoculation to sugarcane and sorghum plants. Out of different methods tried for mechanical inoculation, Bain’s and Matz’s method gave maximum per cent of infection in inoculated sugarcane and three varieties ofSorghum vulgare (cv. M.P.cherry, CSH-5 and CSH-9). The virus was also found to be transmitted by four aphids, viz.Aphis gossypii, Longiunguis sacchari, Myzus persicae andRophalosiphum maidis. Since the virus could be transmitted most efficiently byR. maidis the detailed study was made with it to establish the virus-vector relationship.R. maidis could acquire virus without any pre-acquisition fasting, but fasting has beneficial effect up to 4h on the acquisition power. In case, fasting is increased beyond 4 h, the efficiency of transmission decreased. The aphid acquire the virus within 30 sec. However, optimum acquisition feeding was obtained in 2 min. but the maximum infection was obtained after 30 min infection feeding of test plants. Even a single viruliferous aphid was enough to initiate the infection. The transmission per cent decreased when the aphids were fasted after acquisition feeding of 2h from 60 to 13 per cent. In serial transfers, the aphids cease to be infective very soon while feeding on the test plants. Thus the virus under study was transmitted apparently by typically non-persistent manner and was stylet borne.