Characterization and Biocontrol of Crown Gall Disease in Jordan

Agrobacterium tumefaciens, the causal agent of crown gall, was isolated from peach, almond, apricot, cherry, nectarine, plum, apple, pear, cichorium pupumilum, olive, grapevine, carob, pomegranate and roses. 200 pathogenic isolates were separated into biovars based on biochemical tests. Biovar 1 (60%) and biovar 2 (23.5%) were found to be the most common isolates and isolated mainly from stone fruits in addition to olive, carob, pomegranate, and only biotype 3 isolates were isolated from grapes. Only (70.5%) of the isolates were found to be sensitive to agrocin, where the majority of them belonged to biovar 1. However, 15% of the isolates were found to be intermediate and didn’t belong to any of the biotypes. The different tested bioagents and garlic extract were found to be effective in inhibiting the growth of three tested tumorgenic strains (Jordanian isolate 186, C58 and B6 agrocin sensitive), under laboratory condition , as well as in reducing the percentage of galled tomato or GF677 seedlings