FIG. 3.

Archaeal population dynamics in unamended (A, B), ferrihydrite-amended (C, D), and gypsum-amended (E, F) rice field soil slurries as determined by SSU rDNA (A, C, E) and SSU rRNA (B, D, F) targeted T-RFLP analysis. Shown is the percentage of individual T-RFs relative to the total integrated fluorescence (mean − SD; n = 3 T-RFLP replicates for rDNA and 3 extraction replicates for rRNA). Only T-RFs representing major methanogenic lineages are shown, and minor archaeal T-RFs described previously (6, 32, 44) have been combined as “Diverse.” MB, Methanobacteriaceae; MS, Methanosarcinaceae; MX, Methanosaetaceae; RC-I, rice cluster I; RAF, relative amplicon frequency.