Effects of infection with a spiroplasma virus on the symptoms produced by Spiroplasma citri

Abstract
SUMMARY: Multiplication of a virus resembling spiroplasma‐virus citri type 3 was observed in Spiroplasma citri cells within an infected Madagascar periwinkle plant showing unusually mild symptoms. Sap filtrates from this plant contained virus particles which gave rise to plaques on lawns of the lethal SP‐A strain of S. citri. Transmission of spiroplasmas containing virus to plants already infected with strain SP‐A resulted in suppression of symptoms and a reduction in the number of viable spiroplasmas.