Isolation of Agrobacterium Tumefaciens Strains From

Cultivar of roses (rosa spp.) has been grown in greenhouses in qazvinregion of iran for local markets. agrobacterium tumefaciens strains wereidentified and isolated from six different samples of roses plants importedfrom the netherlands to iran. during august and september of 2012, nearly 2-5% of rose plants in two different greenhouses in the province of qazvin wereobserved with crown gall symptoms on various parts, particularly in the stem.a non-fluorescent gram-negative bacterium was consistently isolated fromdiseased tissues onto king's b medium. the isolated strains were confirmed asagrobacterium using different biochemical and pathogenicity (tumor formingability) tests. four representative strains isolated were aerobic, non-sporing,non-pigmented, motile, rod-shaped, oxidase negative and catalase positive.all of four isolates (atra1, atra2, atrq1 and atrq2) were positive fortumor forming ability for pathogenicity tests on carrot disc and tomato stem.