VIEW ARTICLE

Etiology

Isolation, Culture, and Pathogenicity of the Bacterium Causing Phony Disease of Peach. John M. Wells, Southeastern Fruit and Tree Nut Research Laboratory, U.S. Department of Agriculture, P.O. Box 87, Byron, GA 31008, Present address of senior author: U.S. Department of Agriculture, P.O. Box 231, New Brunswick, NJ 08903; Boligala C. Raju(2), and George Nyland(3). (2)(3)University of California, Department of Plant Pathology, Davis 95616, (2)Current address: Yoder Bros., P.O. Box 68, Alva, FL 33920. Phytopathology 73:859-862. Accepted for publication 19 January 1983. This article is in the public domain and not copyrightable. It may be freely reprinted with customary crediting of the source. The American Phytopathological Society, 1983. DOI: 10.1094/Phyto-73-859.

Fastidious, Gram-negative, xylem-limited bacteria (XLB) were isolated from peach (Prunus persica) trees with symptoms of phony disease. Following inoculation by root infiltration, stunting and severe rosetting of terminal twigs occurred in 3 of 4 cultivar Lovell, 3 of 10 cultivar Halford, and 2 of 10 cultivar Nemagard peach seedlings. The XLB in situ were 0.35 x 3 μm in maximum diameter and length, were present in all inoculated peach seedlings with symptoms typical of phony disease, and were reisolated on BCYE medium 18 mo after the plants were inoculated. Results of ELISA serology with antiserum prepared against the phony peach XLB were similar with bacteria isolated from naturally diseased trees and from artificially inoculated seedlings. The serology, morphology, and ultrastructural properties of the reisolated bacteria were identical to that of XLB present in naturally infected trees and to that of the bacteria used in the original inoculations.