(A) Agarose gel (left gel) and 32 to 41% denaturant DGGE gel (right gel) of phlD fragments amplified from phlD+ reference strains Q2-87, PILH1, Q8r1-96, and F113. Lane M contained the DGGE marker, which included independently amplified phlD fragments from nine reference and indigenous strains. (B) A 40 to 51% denaturant DGGE gel of phlD fragments amplified from phlD+ reference strains CHA0, Pf-5, PGNR1, PINR2, and PINL1. (C) A 32 to 41% denaturant DGGE gel of phlD fragments amplified from phlD+ indigenous isolates obtained from the rhizosphere of multiple plant species. DGGE groups A (PWB152), B (PWB134), C (PSB516), D (PSB211), E (PSB113), F (PPB617), and Z (PWB5516) were included.