Mechanical Transmission of the Infectious Variegation Virus of Citrus

Abstract

INFECTIOUS variegation was described as a possible virus disease of citrus in 1931 by Petri¹. His description of symptoms and his illustrations are similar to those reported by Fawcett and Klotz², who transmitted the causal agent by bud-grafting from variegated lemon to sour orange. They noticed that some of the symptoms were similar to those associated with psorosis and suggested that the diseases might possibly be related. Klotz and Fawcett³noted that crinkly leaf of lemon is sometimes associated with infectious variegation. Fawcett and Bi tancourt⁴ were uncertain whether infectious variegation differed sufficiently from crinkly leaf to be considered a separate disease. From cross-protection studies, Wallace⁵ concluded that infectious variegation is caused by a strain of the psorosis virus. Grant and Smith⁶ reported infectious variegation in Florida and transmitted the causal agent by bud and leaf-piece grafts to several different species of citrus.