A novel method of storage for potato viruses

A simple virus storage method employing use of sucrose for the long-term storage of potato viruses PVX, PVS, PAMV, PVM, PVA and PVY was tested and found effective for PVX, PVS and PAMV. It involved storage of shredded virus-infected leaf tissue in 30% sucrose solution at −20°C in a refrigerator for more than six years. Infectivity and serological activity was demonstrated even after 6 years of storage in case of PVX, PVS and PAMV while only serological activity was evident in case of PVM. Both infectivity and serological activity were lost in case of PVA and PVY even though virions of these viruses were still observable in electron microscope. Amplification of coat protein gene of PVX, PVS and PVA and of P1 protein gene of PVY with immunocapture reverse transcription PCR (IC-RT-PCR) revealed amplification only in PVX and PVS and not in case of PVA and PVY.