Purification and Partial Characterization of Papaya Ringspot Virus

Abstract

A high incidence of papaya ringspot virus (PRSV) was found during a survey of viruses affecting papaya in Venezuela. The Venezuelan strain has a thermal inactivation point between 52 and 54° C, dilution end point of 10 −4 , and the longevity in vitro was 24 h. The modal length of 167 virus particles was 782 nm. The bouyant density of purified virus particles in CsCl was 1.323 g/cm 3 . The virus nucleic acid was identified as a single stranded RNA molecule. The molecular weight of the virus capsid protein was 28,000 daltons. Purification was carried out by chloroform — carbon tetrachloride, followed by precipitation with 6 % PEG. The virus was further purified in CsCl density gradient.