PMTV / TRV

Soil-borne viruses of potato - Potato mop-top virus (PMTV) and Tobacco rattle virus (TRV)

Both Potato mop-top virus (PMTV) and Tobacco rattle virus (TRV) cause spraing symptoms (necrotic arcs or lines) in the flesh of infected tubers. Such symptoms severely affect the marketability of tubers for the export, processing and packing markets. TRV-induced spraing is indistinguishable from PMTV-induced spraing, highlighting the importance of diagnostic testing in determining the cause of infection.

Both viruses are soil-borne and have different modes of transmission: PMTV is spread by the powdery scab pathogen Spongospora subterranea; TRV is transmitted by free-living nematodes (Paratrichodorus and Trichodorus spp).

Left to Right: Spraing symptoms in the flesh of a tubers, symptoms of PMTV infection on the leaves of a potato plant; vectors of PMTV and TRV: zoospore of Spongospora subterranea (©www.spongospora.ethz.ch/sss.htm) and Trichodorus spp. (©Broom’s Barn Research Centre) respectively.

Left to Right: Spraing symptoms in the flesh of a tubers, symptoms of PMTV infection on the leaves of a potato plant; vectors of PMTV and TRV: zoospore of Spongospora subterranea (©www.spongospora.ethz.ch/sss.htm) and Trichodorus spp. (©Broom’s Barn Research Centre) respectively.

 

Studies at SASA are focussing on maintaining the high health of seed potatoes grown for export. Soil-borne inoculum of PMTV has been shown to be more important then seed-borne inoculum in causing economic outbreaks of disease (view poster). A soil bioassay has been developed to monitor seed growing areas of Scotland. This could prove to be an effective tool in the formulation of advice to growers on both site and cultivar selection.

Outputs:

  • Diagnostics for PMTV and TRV in growing crops and tubers;
  • Studies on the relative importance of PMTV and TRV infection in spraing development in seed potatoes.