Abstract
BACKGROUND/OBJECTIVES: Sium serra is distributed in Korea, China, and Japan. It was first identified as the genus Pimpinella and then reclassified as Sium by Kitagawa. Some Sium species are used as herbal medicine and are often confused with the similar form Ligusticum sinense. In this study, we analyzed the cp genome of S. serra and conducted comparative analyses with the cp genomes of related taxa. METHODS: We extracted gDNA from fresh leaves and sequenced it using Illumina HiSeq2500. For the chloroplast genome assembly, de novo assembly was performed using Velvet v1.2.07. For the annotation, GeSeq and NCBI BLASTN were used. Afterwards, related taxa were analyzed using programs such as DnaSP and MISA. RESULTS: S. serra was excluded from the study on the chloroplast (cp) genome in Sium because it was classified as Pimpinella in China. Therefore, this study aimed to analyze the cp genome of S. serra for the first time and its location within the genus Sium. The complete cp genome of S. serra was 154,755 bp in length, including a pair of inverted repeats, each 26,255 bp, a large single-copy region of 84,581 bp, and a small single-copy region of 17,664 bp. The cp genome comprised 79 protein-coding, 30 tRNA, and 4 rRNA genes. Furthermore, six regions of high nucleotide diversity were identified in the genus Sium. In the genus Sium, 1630 repeats that can serve as markers were also identified. Eight protein-coding genes with high K(A)/K(S) values were under positive selection in the Sium. Our phylogenetic analyses suggest that S. serra was positioned with high bootstrap support within the Sium of the tribe Oenantheae, specifically in the southern Palearctic subclade. CONCLUSIONS: In this study, the S. serra chloroplast genome was sequenced and assembled. The genus Sium formed a monophyletic group; however, as not all the Sium species were included in this study, further research is necessary. This study can serve as foundational data not only for Sium but also for the tribe Oenantheae.