VIEW ARTICLE

Vector relations

Loss of Aphid Transmissibility of Turnip Mosaic Virus. Nobumichi Sako, Laboratory of Plant Pathology, Faculty of Agriculture, Saga University, Saga 840, Japan; Phytopathology 70:647-649. Accepted for publication 10 December 1979. Copyright 1980 The American Phytopathological Society. DOI: 10.1094/Phyto-70-647.

Turnip mosaic virus (TuMV) isolate 31, which previously had been aphid-transmissible, was not transmitted by five species of aphids, to five species of test plants, or from four species of source plants whereas isolate 1 was transmitted at high frequencies. Isolate 1 was transmitted by Myzus persicae that had fed through artificial membranes on extracts from infected turnip leaves, while aphids were unable to transmit isolate 31 from extracts of infected turnip leaves. Addition of a soluble fraction from turnip infected with isolate 1 to partially purified virus of the same isolate resulted in aphid transmission of isolate 1, but no transmission resulted when mixtures of either partially purified virus of isolate 1 plus the soluble fraction of isolate 31 or the reverse combination were used for acquisition. The evidence suggests that a helper component required for aphid transmission of TuMV occurred in turnip leaves infected with the aphid-transmissible isolate but not in leaves infected with the aphid-nontransmissible isolate. Possible mechanisms for the loss of aphid transmissibility of TuMV are discussed.