Four isolates of EMV (eggplant mosaic virus - tymovirus group) were preserved in crude extracts from systemically-infected plants. EMV-Al (Abelia strain), EMV-Sc (Scottish strain), EMV-ts (type-strain) and TWNV (tomato white necrosis virus) which induce symptoms in Chenopodium amaranticolor, C. murale, C. quinoa (Family Chenopodiaceae), Datura stramonium, Lycopersicon esculentum and Nicotiana glutinosa (family Solanaceae) plants were maintened in leaf extrats obtained from these species. The extracts were kept at room temperature, at about 5+C and at about 20+C. Sap containing viruses were periodically inoculated in test-plants (datura and glutinosa) in order to determine the longevity in vitro. It was verified that viruses remained infective for longer periods if extratcs were kept at low temperatures as compared with those maintained at room temperature. In the case of sap juice from datura and glutinosa plants, EMV isolates remained infective respectively up to 413 and 282 days at about -20+C. However, many negative results were obtained with Chenopodium species even when freshly prepared leaf juice were used. This fact may be understood by the presence of virus inhibitors in these plants. Only C. quinoa is a valuable host to be used to preserve four EMV isolates, although for a short period (more than 53 and less than 80 days). The present paper reports the successful use of keeping infected leaf juices for preserving the infectivity of some tymoviruses.
tymoviruses; storage in leaf juices; Solanaceae; Chenopodiaceae