Abstract
In aphid transmission tests with turnip mosaic virus (TuMV) and watermelon mosaic virus (WMV), Myzus persicae acquired and transmitted simultaneously TuMV and WMV after prior acquisition of WMV-helper component (HC) from infected leaves and the virus specificity of the HC was confirmed. The aphid, M. persicae could transmit both viruses but Aphis craccivora could transmit only TuMV. Dactynotus gobonis transmitted TuMV efficiently but WMV rarely. However, the latter two aphid species, unlike M. persicae, did not acquire TuMV from purified preparations after prior acquisition of WMV-HC from infected leaves, suggesting some dissimilarity to aphid species. M. persicae, acquired HC from WMV- or potato virus Y (PVY)-infected leaves and then fed on purified TuMV by feeding through membranes, lost ability to transmit TuMV after 10 to 30min on healthy plants or after 7 to 9hr in glass containers; they acquired WMV- or PVY-HC after feeding for 2min to 9hr on a source, but the shorter acquisition feedings enabled them to acquire and transmit TuMV the more efficiently. These results indicate that HC already acquired by vectors might lose the ability to interact with virus particles when the acquisition feeding is prolonged.
