Distribution of replicon specific genes in the tested Rlt nodule isolates. Southern hybridization assays were carried out with several chromosome and plasmid markers of RtTA1 as molecular probes. The position of a given markers in RtTA1 genome was shown in the left column. Positive hybridization was colored regarding its location in one of the following genome compartments of Rlt isolates: chromosome (red), chromid-like (violet), plasmids (blue) and pSym (green); (-) indicates that given marker was not detected within a genome under applied Southern hybridization conditions. The letters a-f below the strains name indicate respective plasmids, ch-chromosome.