Complete chloroplast genome sequencing support Angelica decursiva is an independent species from Peucedanum praeruptorum

Peucedani Radix is the dry root of Peucedanum praeruptorum of the umbelliferous family, but the dry root of Angelica decursiva was also the source of Peucedani Radix in the past. As one of the most popular traditional Chinese medicinal herbs, the certified source of Peucedani Radix is still disputed. To better understand the relationship between A. decursiva and P. praeruptorum, we sequenced their chloroplast (cp) genomes. The gene structure, codon usage bias, repeat, simple sequence repeat (SSR), as well as their borders of inverted repeat (IR) regions of the two cp genomes are analyzed to identify potential genetic markers. Great variation is exhibited in the repeat sequences of IR, large single copy regions and the SSRs of the two cp genomes, which can be used as molecular markers to distinguish them. The phylogenetic analysis also indicates that they belong to two different genera in Apiaceae family: A. decursiva is an Angelica plant and P. praeruptorum is a Peucedanum plant. Our observations suggest that the two species are somewhere different in gene features, which contributes to support A. decursiva as an independent species from P. praeruptorum. The results also provide new evidence that A. decursiva should not be regarded as the certified source of Peucedani Radix in taxonomy.