Aphid inoculation of plants with viruses, viral ribonucleic acid, and hybrid virus

While probing or feeding on leaves, Myzus persicae produced wounds that resulted in lesions when virus was applied later. Lesions were also produced on leaves covered with tobacco mosaic virus (TMV), tobacco mosaic virus ribonucleic acid (TMV-RNA), brome mosaic virus (BMV), or hybrid BMV (BMV-protein/TMV-RNA) when these leaves were subsequently exposed to aphids. With TMV the number of lesions increased with increasing virus concentration. Keeping plants in the dark reduced the number of lesions produced by aphids, but increased those produced by mechanical inoculation. Nicotiana glutinosa was more susceptible to inoculation of TMV by aphids than was N. tabacum var. Xanthi nc. It is concluded that infectible sites produced by mechanical means differ from those produced by aphids.Aphids could not transmit TMV-RNA, BMV, BMV-RNA, or hybrid BMV from a virus-covered leaf to a healthy leaf. However, BMV and TMV could be recovered from the mouthparts of aphids which had fed or probed on virus-covered leaves.