Ecology and Epidemiology

- Survival and virus reservoirs

Tobacco ring spot virus, (TRSV) is able to survive in many plants, including weeds (Physalis spp., Phytolacca americana, Melilotus indica, Lespedeza ...). Soybean and alfalfa are also susceptible hosts.


- Transmission and dissemination

The virus is transmitted by ectoparasitic nematodes of the genus Xiphinema, including Xiphinema americana. The nematode transmits TRSV (figure 1) during parasitic activities on tobacco roots. Sometimes the virus is also transmitted by several insects such as grasshoppers and thrips, during their feeding on plants. The soil seems to contribute to the spread of this virus, probably via nematode vectors. Contaminations occur from plant to plant during cultivation operations in the nursery, and during topping and suckering in the field. These activities help to spread the disease. This virus is not known to be transmitted with seed.