[Incompatibility among indigenous plasmids of Sinorhizobium fredii strains and its application for plasmid curing]

The indigenous plasmids of S. frediii HN01 and WWG18 were labeled with Tn5-MobsacB. Those plasmids were cured on TY medium containing 10% sucrose to identify its function. The pSymHN01b of HN01 was transferred into WWG18SR and C361SR. The results of plasmid detection, curing and pot plant experiment revealed that the incompatibility was existed between pSym-HN01b and symbiotic plasmid of WWG18SR or the third plasmid of C361SR. But it was compatible with the nonsymbiotic plasmid of WWG18SR and symbiotic plasmid of C361SR. Using plasmid incompatibility, The symbiotic plasmid of WWG18SR and one nonsymbiotic plasmid of C361SR were eliminated successfully.