M. Al-Ghazawi1, M. Abou Ghorra2 and M. J. Mendo1
(1) Plant Protection Research Administration, General Commission for Scientific Agricultural Research, Damascus, Syria; (2) Plant Protection Department, Faculty of Agriculture, University of Damascus, Syria.
Pages 134-141
35 samples showing symptoms of crown gall disease tumors were collected from different fruit trees (pears, apples, almonds and dwarf apples) from the governorates of Quneitra, Homs, Swaidaa and Damascus during the period 2020-2021. 85 isolates were isolated from galls, 46 isolates of them were pathogenic on carrot and potato discs, squash fruit and sunflower plants and showed a typical colony shape on growth media. Biochemical and molecular tests were done on the isolates and all of them were found to belong to Agrobacterium tumefaciens, Isolates were segregated according to biochemical tests into three biovars: I, II and a third one in the middle. The pathogen was detected molecularly by PCR, using VCF3/VCR3 primers which target VirC gene located on the Ti plasmid, and can detect all tumorigenic strains of Agrobacterium spp., and this was confirmed by detecting the virulence gene Vird2 using VIRD2A-VIRD2C primers pair. Opine type carried on Ti plasmids was determined using two specific primers which showed that all isolates did belong to the nopaline type and none of the isolates tested belonged to the octopine type.
Crown gall, PCR, Agrobacterium tumefaciens, nopaline.
https://doi.org/10.22268/AJPP-001393 
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