Preservation of the Virus of Tomato Spotted Wilt in Dried Plant Material

Abstract

IT is difficult to obtain accurate information about the properties of viruses which lose their infectivity in vitro too quickly. Tomato spotted wilt virus is one of these, and investigations on it are further limited by the fact that it is inactivated at comparatively low temperatures (35° C). The in vitro life of tomato spotted wilt virus was reported by Bald and Samuel¹ to be about four hours in undiluted expressed juice held at room temperature. Subsequent work by Best and Samuel² and by Best³ showed that the factors causing inactivation were the pH value of the juice and a tyrosinase catalysed oxidation, and that by controlling the pH value and redox potential of the medium⁴ the virus could be maintained infective in solution for thirty-five days at 2° C.