Dendrogram showing genetic relationships among the isolates of S. meliloti and S. medicae. The UPGMA method was used for cluster analysis. G-1 to G-13: genotypic clusters. The isolates from the same phenotypic clusters (clusters P-1 to P-11, Figure 3) are denoted by the same colour, as shown in Figure 3. The numbers indicate S. meliloti isolate # and the numbers with asterisk (*) indicate S. medicae isolate #.