The complete chloroplast genome sequence of Artemisia stechmanniana (Asteraceae): genome structure and phylogenetic analysis

Artemisia stechmanniana, also known as A. sacrorum, belongs to Artemisia in Asteraceae family. A. stechmanniana is also a traditional Chinese folk medicine.The medicinal value of A. stechmanniana has a long history and its remarkable hepatoprotective effects have been widely recognized among traditional practitioners. Artemisia species has plasticity, complex genetics and polyploidy, and the role of morphological characteristics as the sole factor of classification is limited, so taxonomic relationships remain controversial. The development of high-resolution genetic markers is important to facilitate species identification, phylogeny and the medicinal value of A. stechmanniana. In this paper, the chloroplast (cp.) genome of A. stechmanniana was sequenced, assembled and analyzed. The genome of cp. with 151,152 bp in size has a typical tetrad structure. Totally 133 genes were annotated in the complete cp. genome, in which the number of protein-coding, tRNA and rRNA genes was 88, 37 and 8, respectively. There were 41 simple sequence repeats in the cp. genome, which were mostly rich in A/T and located in intergenic spacer (IGS). As revealed by the analysis, the cp. genome was conserved, but non-coding regions were more diverse than coding regions and the IR region was highly conserved as compared to a single copy. The results of phylogenetic analysis manifested that A. stechmanniana was close to A. tangutica. The findings can be used for epidemiological genetics research, enrich our understanding of cp. genomics and provide valuable genetic resources for species recognition, molecular breeding and intraspecific diversity studies of Artemisia species.