Ecology and Epidemiology

- Survival and virus reservoirs

The host range of potato virus Y (PVY) seems limited to the cultivated Solanaceae: potato (figure 1), pepper (figure 2), tomato and tobacco, as well as various solanaceous weeds (Solanum nigrum, Portulaca oleracea, Senecio vulgaris, Physalis spp. etc..) which ensure its conservation between crops and during winter.


- Transmission et dissemination

At least 25 species of aphids are known to transmit PVY in a non-persistent manner. Myzus persicae, the green peach aphid, seems to be the most frequent vector in temperate regions. Myzus nicotianae is also a commonly reported vector in the United States. The virus is acquired by the vector in a few seconds of feeding and a small number of virus particles are sufficient for an effective transmission. However, PVY acquisition by aphids requires the presence of a protein of viral origin in infected cells where it performs the role of an assistant or a "helper component". Only virus particles obtained in the presence of this protein are retained on the maxillary stylets for later transmission. The efficiency of transmission depends on both the aphid vector species and the virus strain.

In addition to Solanaceae, the virus can be mechanically inoculated into several species of Chenopodiaceae, Amaranthaceae, Leguminaceae and Compositae (or Asteraceae). The virus does not seem to spread by plant contact or seeds.