VIEW ARTICLE

Vector Relations

Characteristics of and Factors Affecting Helper-Component-Mediated Aphid Transmission of a Potyvirus. B. Raccah, Department of Plant Pathology, University of Kentucky, Lexington 40546, Permanent address of senior author: Virus Laboratory, Agricultural Research Organization, Volcani Center, Bet Dagan, Israel; T. P. Pirone, Department of Plant Pathology, University of Kentucky, Lexington 40546. Phytopathology 74:305-308. Accepted for publication 27 September 1983. Copyright 1984 The American Phytopathological Society. DOI: 10.1094/Phyto-74-305.

Purified tobacco etch virus, in the presence of helper component (HC), could be acquired and transmitted in the brief probes (<30 sec) characteristic of transmission of potyviruses from plants. The ability to transmit membrane-acquired virus following postacquisition fasting or feeding was also similar to that for plant-acquired virus, provided appropriate concentrations of HC and virus were used. Reduced retention times resulted when the concentration of either virus or HC was decreased, but loss of virus was the primary factor in determining the duration of retention. When HC and virus were acquired sequentially, HC efficacy was maintained in a number of buffers in the pH range 5- 10, and buffer composition rather than its pH was more likely to adversely affect HC efficacy. The effect of “adverse” buffers was not to inactivate HC, because when HC was incubated in such buffers and virus was mixed with HC before acquisition, levels of transmission were much higher than when HC and virus were acquired sequentially. The implications of this finding relative to understanding the HC-virus interaction are discussed.