Comparative analysis of complete chloroplast genomes sequencesof Arctium lappa and A. tomentosum

Arctium lappa and A. tomentosum are known medicinal plants in China. The complete chloroplast genomes from A. lappa and A. tomentosum were sequenced using Illumina sequencing technology. The total genome sizes of the complete chloroplast genomes of A. lappa and A. tomentosum were 152 767 bp and 152 688 bp, respectively, and contained a pair of inverted repeats of the same length (15,181 bp). The small single-copies were 18 584 bp and 18 582 bp, and the large single-copies were 83 821 bp and 83 744 bp, respectively. We identified and annotated 134 and 126 genes from A. lappa and A. tomentosum including, respectively, 90 and 89 protein-coding genes, 36 and 29 tRNAs, and eight rRNAs. A. lappa was found to have 10 tRNAs different from those in A. tomentosum, and A. tomentosum had three tRNAs different from those in A. lappa. There were only two types of simple sequence repeats of two species, mononucleotide and dinucleotide, and the sequences were A and T rich. In addition, the two ways of phylogenetic analysis show that the position of A. lappa and A. tomentosum is consistent within Asteraceae.