The Complete Chloroplast Genome Sequences of Aconitum pseudolaeve and Aconitum longecassidatum, and Development of Molecular Markers for Distinguishing Species in the Aconitum Subgenus Lycoctonum.

Aconitum pseudolaeve Nakai and Aconitum longecassidatum Nakai, which belong to the Aconitum subgenus Lycoctonum, are distributed in East Asia and Korea. Aconitum species are used in herbal medicine and contain highly toxic components, including aconitine. A. pseudolaeve, an endemic species of Korea, is a commercially valuable material that has been used in the manufacture of cosmetics and perfumes. Although Aconitum species are important plant resources, they have not been extensively studied, and genomic information is limited. Within the subgenus Lycoctonum, which includes A. pseudolaeve and A. longecassidatum, a complete chloroplast (CP) genome is available for only one species, Aconitum barbatum Patrin ex Pers. Therefore, we sequenced the complete CP genomes of two Aconitum species, A. pseudolaeve and A. longecassidatum, which are 155,628 and 155,524 bp in length, respectively. Both genomes have a quadripartite structure consisting of a pair of inverted repeated regions (51,854 and 52,108 bp, respectively) separated by large single-copy (86,683 and 86,466 bp) and small single-copy (17,091 and 16,950 bp) regions similar to those in other Aconitum CP genomes. Both CP genomes consist of 112 unique genes, 78 protein-coding genes, 4 ribosomal RNA (rRNA) genes, and 30 transfer RNA (tRNA) genes. We identified 268 and 277 simple sequence repeats (SSRs) in A. pseudolaeve and A. longecassidatum, respectively. We also identified potential 36 species-specific SSRs, 53 indels, and 62 single-nucleotide polymorphisms (SNPs) between the two CP genomes. Furthermore, a comparison of the three Aconitum CP genomes from the subgenus Lycoctonum revealed highly divergent regions, including trnK-trnQ, ycf1-ndhF, and ycf4-cemA. Based on this finding, we developed indel markers using indel sequences in trnK-trnQ and ycf1-ndhF. A. pseudolaeve, A. longecassidatum, and A. barbatum could be clearly distinguished using the novel indel markers AcoTT (Aconitum trnK-trnQ) and AcoYN (Aconitum ycf1-ndhF). These two new complete CP genomes provide useful genomic information for species identification and evolutionary studies of the Aconitum subgenus Lycoctonum.