Pathological and biological studies on crown gall disease of stone fruits.

Abstract

Thirteen isolates were obtained from roots of different hosts i.e. peach, apple, almond and roselle on selective media such as D1 and Patel's medium. Morphological, physiological and biochemical tests proved that the 13 isolates belonged to Agrobacterium tumefaciens (Conn). Further tests to verify the identity of these isolates as A. tumefaciens such as Biolog system and serological tests like immunofluorescence, dot-immunobinding assay, double diffusion technique and immunoelectrophoresis technique. Also, the ability of different isolates to use nopaline and octopine was tested. Also, some bacterial antagonists were tested against different isolates of A. tumefaciens in vitro. These isolates were applied in a field experiment and a successful biological control of crown gall was achieved using one isolate of the antagonist Agrobacterium radiobacter.