PHYLOGENETIC-RELATIONSHIPS BETWEEN AGROBACTERIUM-VITIS ISOLATES AND THEIR TI PLASMIDS

A collection of 76 Agrobacterium vitis isolates was analyzed by severa l molecular methods, PCR analysis of the 16S-23S intergenic spacer (IG S) region of the ribosomal DNA, restriction patterns of total DNA, and hybridization with different Ti plasmid probes enabled us to distingu ish chromosomal and Ti plasmid characteristics. The various strains co uld be divided into several chromosomal groups based on IGS patterns, Each group was found to contain a particular type of Ti plasmid (nopal ine, vitopine, and octopine/cucumopine Ti plasmids), although a few ex ceptions occur which may represent rare natural transconjugants, The T i plasmid of isolate CG474 did not fit within existing A, vitis Ti pla smid groups.