New Evidence on the Mechanism of Aphid Transmission of Potato C and Potato Aucuba Mosaic Viruses

Abstract

A few plant viruses are unusual in that they are not transmitted by insects from plants in which they are present alone but are transmitted from plants also infected with another (helper) virus that is insect-transmitted. In all the reported instances, the helper virus has a species of aphid as its vector. They all fall into one of two groups, according to the manner of transmission by aphids of the helper virus. The helper virus may be non-persistent, when the aphids acquire and transmit the virus within a few min. but lose their ability to infect after a few probes on a healthy leaf, or it may be persistent (circulative), when the aphids need to feed on infected plants for long periods before becoming infective but then remain infective for a long period, during which they can infect several plants.