TGGE separation patterns of rhizoplane samples. Individual examples of samples taken after 2, 4, 6, 8, and 10 weeks from microcosms with alfalfa in FAL soil (lanes 1 to 5), alfalfa in BBA soil after 10 weeks (lane 6), bean after 8 weeks (lane 7), and clover after 11 weeks (lane 8). After sampling and rRNA isolation, the target sequence amplification was done according to the general protocol (see Fig. 1 legend and the text).