Highly tumorigenic Agrobacterium tumefaciens strain from crown gall tumorsof chrysanthemum

A wild-type Agrobacterium tumefaciens strain CNI5 isolated from crown gall of chrysanthemum (Dendranthema grandiflora Tzvelev) was characterized. Stra in CNI5 was classified into biovar 1, based on physiological and biochemica l characteristics, and was resistant to ampicillin. Strain CNI5 induced tum ors at a higher frequency and on a larger area of explants in most tested p lant species, especially in chrysanthemum cultivars, than the octopine-type strain C58C1cm(r) (pTiB6S3). Agropine and mannopine were detected in tumor s induced by strain CNI5 and were specifically catabolized by this strain. Strain CN15 harbored five plasmids including one plasmid that shared sequen ce similarity to TL-DNA of the octopine-type Ti plasmid and four cryptic pl asmids.