The long-term preservation of potato virus Y and watermelon mosaic virus in liquid nitrogen in comparison to other preservation methods. 1978
Abstract
Samples of watermelon mosaic virus (WMMV), consisting of clarified sap of diseased squash plants, were found to be very infective after more than 4 years of storage if the samples had been deep frozen at -18 °C, and to have lost most of their infectivity within 4 years of preservation by freeze drying and subsequent storage of the samples at 4 °C.
Potato virus Y (PVY) inocula, consisting of samples of clarified sap of diseased red peppers, lost their infectivity in less than 4 years if the samples had been deep frozen at -18 °C but retained their infectivity for more than 4 years if the samples had been freeze dried and stored at 4 °C.
A decrease in infectivity of both viruses in the deep frozen at -18 °C and freeze dried inocula could be observed even during the first months of storage. However, samples of clarified sap stored in or over liquid nitrogen maintained their activity for at least 22 months for WMMV and 32 months for PVY with no indication of a decrease in infectivity of the viruses. Storage in or over liquid nitrogen. seems therefore a very promising long-term preservation method for plant viruses.