IDENTIFICATION OF AGROBACTERIUM STRAINS BY PCR-RFLP ANALYSIS OF PTI AND CHROMOSOMAL REGIONS

Chromosomes and Ti plasmids of 41 Agrobacterium strains, belonging to biovars 1, 2, 3, and Agrobacterium rubi species were characterized by the restriction fragment length polymorphism of PCR-amplified DNAs. Pr ofiles that were obtained by the analysis of the amplified 16S rDNA co nfirmed the grouping of the strains according to their species. Higher polymorphism was detected in the intergenic spacer between the 16S rD NA and 23S rDNA genes, allowing efficient discrimination of strains. I dentification of most strains was possible, and the genetic relatednes ses of Agrobacterium strains could be estimated. The analysis of the p lasmid Ti encoded regions between the tmr and nos genes, and the virA and virB(2) genes, allowed fingerprinting of Ti plasmids. Genomic typi ng by the rapid PCR-RFLP method is thus shown to be useful for an inde pendant identification of strains and of the conjugative Ti plasmids.