Identification of bacterial knot disease agent Pseudomonassavastanoi Pv. Savastanoi and biological control of disease byAntagonistic bacteria in Tekirdag

Olive knot disease on olives (Olea europaea) is caused by the bacterium Pseudomonas savastanoi pv. savastanoi (syn. P. syringae pv. savastanoi) which infects through wounds. The galling typical of this disease is caused by phytohormones produced by the bacteria, which cause proliferation of cells surrounding the infection. This study was conducted in 2015- 2017 in several provinces of Tekirdag in Trakya region. To investigate the identification and prevalence of Pseudomonas savastanoi pv. savastanoi, totaly 78 infected knot samples collected from several olive cultivars and 52 isolates of bacterium were detected at classical characterization tests. All of the isolates were gram negative and were found to be in the LOPAT 1B group with oxidase, pectolytic activity, levan and arginine dihydrolase negative, hypersensitivity reactions in tobacco leaves. It has therefore been identified as pseudomonas savastanoi pv. savastanoi. In addition, it has been determined that the prevalence of olive branch cancer disease in the province of Tekirdağ is 33%. From olive gardens, 50 pieces of flowers and leaves collected from olive trees and 60 pieces of isolates were obtained from soil. The hypersensitivity reactions of these isolates to tobacco leaves were negative. As a result of double-culture experiments with pathogen in laboratory conditions, among the 110 isolates, 23 of them produced an inhibition zone of 1-10.8 mm.