SURVIVAL AND PERSISTENCE OF BIOLUMINESCENT XANTHOMONAS-CAMPESTRIS PV CAMPESTRIS ON HOST AND NONHOST PLANTS IN THE FIELD ENVIRONMENT

Dispersal and persistence of a pathogenic strain of Xanthomonas campes tris pv. campestris, genetically engineered to bioluminesce, was follo wed in and on host and non-host plants in the field environment, Black rot susceptible cabbage plants were mist inoculated with the biolumin escent strain only, or were mist inoculated with X. campestris pv. ves icatoria in or a weakly pathogenic strain of X, c. campestris 1 week b efore challenge inoculation with the bioluminescent strain. Growth of the bioluminescent strain was detected with. a low-light, charge-coupl ed device camera or through bioluminescence measurements of broth-enri chment cultures of leaf disk samples, Bioluminescent X, c. campestris could often be observed as populations on symptomless leaves or in les ions, and persisted as a vascular endophyte for more than 6 months thr oughout the winter glowing season, Dispersal to cruciferous and non-cr uciferous weeds was frequently detected, Pre-inoculation with X. c. ve sicatoria or the weakly pathogenic X, c. campestris did not significan tly affect the movement and persistence of the bioluminescent strain n or reduce the incidence of black rot disease.