Fig. 4From: Diversity of alkane hydroxylase genes on the rhizoplane of grasses planted in petroleum-contaminated soilsEvolutionary distance dendrogram of retrieved CYP153 sequences with the reference sequences from NCBI database based on OTU grouping. Numbers in parenthesis show the numbers of sequences affiliated to the same OTU and group. Symbols are used to distinguish different clone libraries. Numbers on the right-hand of the symbols reflect the numbers of sequence within each clone library. Bootstrap values below 50 % are not shownBack to article page