The genus Angelica (Apiaceae) comprises valuable herbal medicines. In this study, we determined the complete chloroplast (CP) genome sequence of A. polymorpha and compared it with that of Ligusticum officinale (GenBank accession no. NC039760). The CP genomes of A. polymorpha and L. officinale were 148,430 and 147,127 bp in length, respectively, with 37.6% GC content. Both CP genomes harbored 113 unique functional genes, including 79 protein-coding, four rRNA, and 30 tRNA genes. Comparative analysis of the two CP genomes revealed conserved genome structure, gene content, and gene order. However, highly variable regions, sufficient to distinguish between A. polymorpha and L. officinale, were identified in hypothetical chloroplast open reading frame1 (ycf1) and ycf2 genic regions. Nucleotide diversity (Pi) analysis indicated that ycf4–chloroplast envelope membrane protein (cemA) intergenic region was highly variable between the two species. Phylogenetic analysis revealed that A. polymorpha and L. officinale were well clustered at family Apiaceae. The ycf4-cemA intergenic region in A. polymorpha carried a 418 bp deletion compared with L. officinale. This region was used for the development of a novel indel marker, LYCE, which successfully discriminated between A. polymorpha and L. officinale accessions. Our results provide important taxonomic and phylogenetic information on herbal medicines and facilitate their authentication using the indel marker.

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.

Prunus africana is an endangered medicinal plant and hence new propagation methods are urgently required to increase its populations. Unfortunately, propagation through seeds is challenging due to its long flowering cycle and recalcitrant seeds. We developed a protocol for micropropagation using nodal segment explants. A woody plant medium supplemented with vitamins, 15 g L⁻¹ sucrose, and 1.0 mg L⁻¹ 6-benzylaminopurine (BAP) supported the optimum rate (100%) of axillary shoot initiation. Supplementation with 15 g L⁻¹ sucrose and 1.5 mg L⁻¹ indole-3-acetic acid (IAA) provided the optimum rate (75%) of root initiation. Rooted plantlets were successfully planted in sterilized horticultural soil containing perlite (2:1 v/v) and the survival rate was 98% following acclimatization. The photosynthetic rate assessed using FlourPen FP110 series showed that the ratio of variable fluorescence to maximum fluorescence mean value for in vitro regenerated P. africana (0.830 ± 0.0008) was similar to that of the maternal P. africana plant (0.825 ± 0.005), indicating similarity in their photosynthetic performance; a pivotal process for growth and development. The Fourier transform near-IR (FT-NIR) spectrometer analysis of the in vitro regenerated and the maternal P. africana plant samples exhibited homogeneity in the absorbance peaks at 8,273, 6,344, and 4,938–4,500 cm⁻¹ associated with lipids, starch, and proteins. The genetic fidelity of regenerated plants was confirmed using the randomly amplified polymorphic DNA (RAPD) technique. Our protocol is suitable for use in large-scale P. africana to meet the increasing demands for it in the global market.

The genus Cuscuta (Convolvulaceae) comprises well-known parasitic plants. Cuscuta species are scientifically valuable, as their life style causes extensive crop damage. Furthermore, dried seeds of C. chinensis are used as a Korean traditional herbal medicine. Despite the importance of Cuscuta species, it is difficult to distinguish these plants by the naked eye. Moreover, plastid sequence information available for Cuscuta species is limited. In this study, we distinguished between C. chinensis and C. japonica using morphological characterisation of reproductive organs and molecular characterisation of chloroplast genomes. The differences in morphological characteristics of reproductive organs such as style, stigma, infrastaminal scale, seed shape and testa ornamentation were useful for distinguishing between C. japonica and C. chinensis. Analysis of chloroplast genomes revealed drastic differences in chloroplast genome length and gene order between the two species. Although both species showed numerous gene losses and genomic rearrangements, chloroplast genomes showed highly similar structure within subgenera. Phylogenetic analysis of Cuscuta chloroplast genomes revealed paraphyletic groups within subgenera Monogynella and Grammica, which is consistent with the APG IV system of classification. Our results provide useful information for the taxonomic, phylogenetic and evolutionary analysis of Cuscuta and accurate identification of herbal medicine.

Accurate identification of the plant species that are present in herbal medicines is important for quality control. Although the dried roots of Aralia continentalis (Araliae Continentalis Radix) and Angelica biserrata (Angelicae Pubescentis Radix) are used in the same traditional medicine, namely Dok-Hwal in Korean and Du-Huo in Chinese, the medicines are described differently in the national pharmacopeia. Further confusion arises from the distribution of dried Levisticum officinale and Heracleum moellendorffii roots as the same medicine. Medicinal ingredients from all four plants are morphologically similar, and discrimination is difficult using conventional methods. Molecular identification methods offer rapidity and accuracy. The internal transcribed spacer 2 (ITS2) region of the nuclear ribosomal RNA gene (rDNA) was sequenced in all four plant species, and the sequences were used to design species-specific primers. Primers for each species were then combined to allow sample analysis in a single PCR reaction. Commercial herbal medicine samples were obtained from Korea and China and analyzed using the multiplex assay. The assay successfully identified authentic medicines and also identified inauthentic or adulterated samples. The multiplex assay will be a useful tool for identification of authentic Araliae Continentalis Radix and/or Angelicae Pubescentis Radix preparations in Korea and China.

Dried roots of Dipsacus asper (Caprifoliaceae) are used as important traditional herbal medicines in Korea. However, the roots are often used as a mixture or contaminated with Dipsacus japonicus in Korean herbal markets. Furthermore, the dried roots of Phlomoides umbrosa (Lamiaceae) are used indiscriminately with those of D. asper, with the confusing Korean names of Sok-Dan and Han-Sok-Dan for D. asper and P. umbrosa, respectively. Although D. asper and P. umbrosa are important herbal medicines, the molecular marker and genomic information available for these species are limited. In this study, we analysed DNA barcodes to distinguish among D. asper, D. japonicus, and P. umbrosa and sequenced the chloroplast (CP) genomes of D. asper and D. japonicus. The CP genomes of D. asper and D. japonicus were 160,530 and 160,371 bp in length, respectively, and were highly divergent from those of the other Caprifoliaceae species. Phylogenetic analysis revealed a monophyletic group within Caprifoliaceae. We also developed a novel sequence characterised amplified region (SCAR) markers to distinguish among D. asper, D. japonicus, and P. umbrosa. Our results provide important taxonomic, phylogenetic, and evolutionary information on the Dipsacus species. The SCAR markers developed here will be useful for the authentication of herbal medicines.