Mechanical Transmission of Galinsoga Mosaic Virus in Soil

Abstract

Galinsoga mosaic virus (GMV) was isolated from Galinsoga parviflora plants growing near Gympie in south-eastern Queensland. Although the virus was always recovered from the roots of naturally infected G. parviflora plants, the tops sometimes contained no detectable virus. When soil collected near naturally infected plilnts was kept moist in a glasshouse for 15 months and periodically planted with seed or seedlings of G. parviflora, the plants continued to become infected. Addition of captafol or ethazol fungicides to the soil had no effect on transmission of GMV in a glasshouse. Air-drying the soil for 20 days abolished its infectivity to G. parvi/lora plants and also decreased the amount of virus directly extractable from it.