FIG. 4.

Evolutionary distance dendrogram showing SSU rDNA sequences of representative soil clones (complete list in Table 1) in relation to known sequences of methanogenic Euryarchaeota and to environmental sequences retrieved from coastal marine environments (SBAR1A and WHAR N [15]), from rice roots (ARR19 and ARR16), and from bulk rice soil (ABS3, ABS9, ABS12, and ABS23 [17, 18]). The scale bar indicates the estimated number of base changes per nucleotide sequence position.