Complete chloroplast genome sequence of the medicinal plant Arctium lappa.

Arctium lappa, commonly called burdock, has a long medicinal and edible history. It has recently gained increasing attention because of its economic value. In this study, we obtained the complete chloroplast genome of A. lappa by Illumina Hiseq. The complete chloroplast genome of A. lappa is a typical circular structure with 152 708 bp in length. The GC content in the whole chloroplast genome of A. lappa is 37.7%. A total of 37 tRNA genes, 8 rRNA genes, and 87 protein-coding genes were successfully annotated. And the chloroplast genome contains 113 unique genes, 19 of which are duplicated in the inverted repeat. The distribution of 39 simple sequence repeats was analysed, and most of them are in the large single-copy (LSC) sequence. An inversion comprising 16 genes was found in the LSC region, which is 26 283 bp long. We performed multiple sequence alignments using 72 common protein-coding genes of 29 species and constructed a Maximum Parsimony (MP) tree. The MP phylogenetic result shows that A. lappa grouped together with Carthamus tinctorius, Centaurea diffusa, and Saussurea involucrata. The chloroplast genome of A. lappa is a valuable resource for further studies in Asteraceae.

[Study on high throughput sequencing identification of Fructus Arctii and five counterfeit species mix power].

Fructus Arctii is a traditional Chinese medicine. The main counterfeit species are the seeds of Arctium tomentosum, Onopordum acanthium, Silybum marianum, Saussurea costus, Amorpha fruticosa. Traditional identification methods or molecular barcoding techniques can identify Fructus Arctii and its counterfeit species. However, the identification of the mixture of it and its spurious species is rarely reported. In this paper, we sequenced the ITS2 sequences of Fructus Arctii and 5 kinds of spurious species mix powder by high-throughput sequencing to identify the mixed powder species and providing new ideas for the identification of Fructus Arctii mix powder. The total DNA in mixed powder was extracted, and the ITS2 sequences in total DNA was amplified. Paired-end sequencing was performed on the DNA fragment of the community using the Illumina MiSeq platform. The sequence was analyzed by the software FLASH, QIIME and GraPhlAn etc. The results showed that the high quality ITS2 sequences of 39910 mix samples were obtained from the mixed samples, of which the total ITS2 sequence of the samples genus was 34 935. Phylogenetic analysis showed that the samples contained Fructus Arctii, A. tomentosum, O. acanthium, S. marianum, S. costus and A. fruticosa. Using ITS2 sequences as DNA barcodes, high-throughput sequencing technology can be used to detect the Fructus Arctii and its spurious specie in mixed powder, which can provide reference for the quality control, safe use of medicinal materials of Fructus Arctii and the identification of mixed powder of traditional Chinese medicine.