Molecular Characterization and Survey for Some Isolates from Crown Gall Agrobacterium Vitis on Vineyards in As-Suwayda Governorate Southern Syria

Abstract

field Survey was carried out in grape vineyards in As-Suwayda governorate during 2018- 2019 for Crown gall disease. 40 samples of tumors were collected and 85 isolates were isolated. 61 isolates were clearly pytopathogenic on carrot discs and showed a typical morphological growth on media. Biochemical and Molecular testes were done on 45 selected strains and the results were almost identical and all the isolates were from

Agrobacterium vitis and not to Agrobacterium tumefaciens. The pathogen was detected using VCF3/VCR3 Primers which target virC gene located on Ti plasmid and can detect all tumorigenic strains of Agrobacterium and PGF/PGR primers which detect the (pehA) gene responsible for polygalacturonase enzyme and discriminate A. vitis strains. Isolates were segregated according to molecular tests (PCR) with three specific primer pairs into three main groups, octopine group 80%, nopaline group 7% and vitopine group 13% and none of the isolate has more than one opine on Ti plasmid.