SOME PROPERTIES OF WHEAT STRIATE MOSAIC VIRUS

Abstract

Suspensions of wheat striate mosaic virus prepared with the sediments from high-speed centrifugation (105,000 g) of liquid extracts from viruliferous leafhoppers (Endria inimica Say), infected 63%, 46%, 33%, 5.5%, 3.5%, and 1.6% of the leafhoppers into which they were injected after dilution to 10−0.7, 10−1, 10−2, 10−3, 10−4, and 10−5 respectively. Suspensions of the virus were still infective after they were heated for 10 minutes at 45 °C, but not at 55 °C. Suspensions stored at 4 °C were highly infective after 3 days, but were toxic to the injected insects by the fourth day. Most infectivity was lost after 3 days at −10 °C. Wheat plants did not become infected when mechanically inoculated with suspensions which were infectious to leafhoppers. A specific particle was not correlated with infectivity when suspensions from viruliferous and healthy insects were compared in the electron microscope.