VIEW ARTICLE

Etiology

Relation of Pierce’s Disease Bacterium to a Wilt-Type Disease in Citrus in the Greenhouse. D. L. Hopkins, Professor, Department of Plant Pathology, University of Florida, Agricultural Research Center, Leesburg 32748; Phytopathology 72:1090-1092. Accepted for publication 11 February 1982. Copyright 1982 The American Phytopathological Society. DOI: 10.1094/Phyto-72-1090.

The Pierce’s disease (PD) bacterium produced symptoms in rough lemon (Citrus jambhiri) seedlings in the greenhouse similar to those observed in field trees affected by citrus blight. The symptoms, including dieback of branches and leaf drop, appeared 8–12 mo after inoculation. Water-flow rates were reduced in stem sections of diseased rough lemon seedlings. PD bacteria were detected in stem extracts of rough lemon by immunofluorescence. Survival and multiplication of the PD bacterium in rough lemon petioles were determined by reisolation and dilution plating over a 6-wk period. The PD bacterium also produced a disease in seedlings of the trifoliate orange (Poncirus trifoliata), Carrizo citrange (P. trifoliata × C. sinensis), and Rangpur lime (C. limonia), but not in those of alemow (C. macrophylla), Cleopatra mandarin (C. reticulata), or sour orange (C. aurantium). Symptomatology and varietal susceptibility of this disease were similar to citrus blight.