Figure 5

Neighbor-Joining trees for the representation of the distances among alleles. The alleles belonging to S. medicae isolates are surrounded by a plain-line circle. Only IGS _NOD presents alleles found only in S. meliloti bv. meliloti populations and alleles found only in S. meliloti bv. medicaginis. Consequently, for IGS _NOD , alleles are also divided according the two biovars of S. meliloti, by broken-line circles. Bootstrap values higher than 50% are given in boxes. Nodes with bootstrap values higher than 50% are indicated by plain circles and in case of possible ambiguity, a broken line links the node to the bootstrap value. The interrupted lines have a length of 0.0986 for IGS _NOD , 0.1075 for IGS _EXO , 0.0456 for IGS _GAB and 0.0421 for IGS _RKP .