Abstract

One pair of primers was designed based on the sequence of tmr locus for specific and sensitive detection of Agrobacterium tumefaciens. Only the A. tumefaciens strain can produce the 236bp target fragment among the fourteen bacterial species that tested. The sensitivity of the specific PCR system was determined by a nested-PCR amplification which can numbered the copies of the template DNA. According to the results, it can give positive band when only 10⁰ copies were in the template. The protocol was carried out for detection A. tumefaciens of twelve soil samples collected from six different gardens in Shanghai where crown gall happened. Two of the samples which collected from symptomless gardens also give the positive band. Based on the results we can make a conclusion that this pair of primers can be a useful tool in detecting A. tumefaciens, especially in detecting latent infection of this devastating pathogen.

Key words: Agrobacterium tumefaciens, detection, polymerase chain reaction (PCR).