Preliminary Studies on Pathogen of Strawberry Virus Disease
Abstract: The strawberry growing in Shanghai suburb was suffered from viral infection with several different kinds of symptoms. Two viral isolates were obtained from the diseased leaves by procedures of chloroform, PEG treatments and of following differential and suerose gradient centrifugations. The electron microscopic observations showed that both of these two isolates have isometric appearance with different sizes about 28—30 nm and 40 nm, respectively. The nature of these isolates was discussed.