Idetification of the Causer of Tomato Pith Necrosis in the Republic of Macedonia

Abstract

In the period from 2005 to 2009 the occurrence of tomato pith necrosis isinvestigated in the Strumica region. A total number of 24 isolates are investigatedin in vitro conditions and for the fi rst time in the Republic of Macedoniathe presence of the plant pathogen bacteria Pseudomonas mediterranea (Cattaraet al., 2002), causer of tomato pith necrosis, is identifi ed. Physiologicalinvestigations show that the colonies of Pseudomonas mediterranea have corrugatedsurface and produce blue-green pigment. Isolates investigated in in vitroconditions show hypersensitive reaction on tobacco leaves, and pathogenicchanges during artifi cial inoculation of tomato and pepper plants. Biochemicalcharacteristics show that the isolates are Gram negative, produce levan andare positive for catalase, urease and oxidase. All investigated isolates showability to dehydrolize arginine but they do nоt have pectolitic activity, do nоtfl uoresce on medium King B, and do not produce indol, H2S or hydrolizeesculine. Other investigated characteristics show that the isolates can reducenitrates to nitrites, accumulate PHB (Poly-β- hydroksibuturate), grow at 4 and37℃, but not at 41℃. The use of different carbohydrates and acid compoundsis investigated with BIOLOG test. The variety of the bacteria is identifi ed withPCR (Polymerase chain reaction).