Linkage Mapping in Rhizobium leguminosarum by means of R Plasmid-mediated Recombination

Abstract

Wild-type R plasmids of the P1 incompatibility group mediated the transfer of chromosomal genes in R. leguminosarum, but only at very low frequencies. Two P1 R plasmids, which were originally selected in Pseudomonas aeruginosa for enhanced donor properties, promoted much higher levels of gene transfer in R. leguminosarum. One of these, R68.45, was used for linkage mapping. All markers tested mapped on a single circular linkage group. Segments of donor chromosome up to at least 1/7 of its total length were transferred and integrated into the recipient chromosome.