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Background: The Synotis (C. B. Clarke) C. Jeffrey & Y. L. Chen is an ecologically important genus of the tribe Senecioneae, family Asteraceae. Because most species of the genus bear similar morphology, traditional morphological identification methods are very difficult to discriminate them. Therefore, it is essential to develop a reliable and effective identification method for Synotis species. In this study, the complete chloroplast (cp.) genomes of four Synotis species, S. cavaleriei (H.Lév.) C. Jeffrey & Y.L. Chen, S. duclouxii (Dunn) C. Jeffrey & Y.L. Chen, S. nagensium (C.B. Clarke) C. Jeffrey & Y.L. Chen and S. erythropappa (Bureau & Franch.) C. Jeffrey & Y. L. Chen had been sequenced using next-generation sequencing technology and reported here. Results: These four cp. genomes exhibited a typical quadripartite structure and contained the large single-copy regions (LSC, 83,288 to 83,399 bp), the small single-copy regions (SSC, 18,262 to 18,287 bp), and the inverted repeat regions (IR, 24,837 to 24,842 bp). Each of the four cp. genomes encoded 134 genes, including 87 protein-coding genes, 37 tRNA genes, 8 rRNA genes, and 2 pseudogenes (ycf1 and rps19). The highly variable regions (trnC-GCA-petN, ccsA-psaC, trnE-UUC-rpoB, ycf1, ccsA and petN) may be used as potential molecular barcodes. The complete cp. genomes sequence of Synotis could be used as the potentially effective super-barcode to accurately identify Synotis species. Phylogenetic analysis demonstrated that the four Synotis species were clustered into a monophyletic group, and they were closed to the Senecio, Crassocephalum and Dendrosenecio in tribe Senecioneae. Conclusions: This study will be useful for further species identification, evolution, genetic diversity and phylogenetic studies within this genus Synotis and the tribe Senecioneae. [ABSTRACT FROM AUTHOR]

Abstract Background The Synotis (C. B. Clarke) C. Jeffrey & Y. L. Chen is an ecologically important genus of the tribe Senecioneae, family Asteraceae. Because most species of the genus bear similar morphology, traditional morphological identification methods are very difficult to discriminate them. Therefore, it is essential to develop a reliable and effective identification method for Synotis species. In this study, the complete chloroplast (cp.) genomes of four Synotis species, S. cavaleriei (H.Lév.) C. Jeffrey & Y.L. Chen, S. duclouxii (Dunn) C. Jeffrey & Y.L. Chen, S. nagensium (C.B. Clarke) C. Jeffrey & Y.L. Chen and S. erythropappa (Bureau & Franch.) C. Jeffrey & Y. L. Chen had been sequenced using next-generation sequencing technology and reported here. Results These four cp. genomes exhibited a typical quadripartite structure and contained the large single-copy regions (LSC, 83,288 to 83,399 bp), the small single-copy regions (SSC, 18,262 to 18,287 bp), and the inverted repeat regions (IR, 24,837 to 24,842 bp). Each of the four cp. genomes encoded 134 genes, including 87 protein-coding genes, 37 tRNA genes, 8 rRNA genes, and 2 pseudogenes (ycf1 and rps19). The highly variable regions (trnC-GCA-petN, ccsA-psaC, trnE-UUC-rpoB, ycf1, ccsA and petN) may be used as potential molecular barcodes. The complete cp. genomes sequence of Synotis could be used as the potentially effective super-barcode to accurately identify Synotis species. Phylogenetic analysis demonstrated that the four Synotis species were clustered into a monophyletic group, and they were closed to the Senecio, Crassocephalum and Dendrosenecio in tribe Senecioneae. Conclusions This study will be useful for further species identification, evolution, genetic diversity and phylogenetic studies within this genus Synotis and the tribe Senecioneae.

In this study, the genome of an endemic Sulawesi's plant, Medinilla tapetemagicum was sequenced using Illumina NextSeq 500 and assembled the whole chloroplast genome. Results showed that the cpGenome is 155,602 bp in size with typical quadripartite structure of a large single copy (LSC) region (85,409 bp), a short single copy (SSC) region (16,629 bp), and a pair of inverted repeats (IRs) regions (26,782 bp). The cpGenome is composed of 132 genes, which consists of 87 protein coding genes, 37 tRNAs, and 8 rRNAs. The sliding window analyses showed that psbB-psbH and ndhF-rpl32 can potentially be used as markers. Microsatellite motifs of mononucleotide A and T dominated in the cpGenome. The phylogenetic trees from the concatenated 76 shared protein coding gene sequences showed the Medinilla clade was monophyletic and M. tapete-magicum is a sister species in the SE Asian clade which contain M. magnifica and M. speciosa. [ABSTRACT FROM AUTHOR]

Abstract Background The era of high throughput sequencing offers new paths to identifying species boundaries that are complementary to traditional morphology-based delimitations. De novo species delimitation using traditional or DNA super-barcodes serve as efficient approaches to recognizing putative species (molecular operational taxonomic units, MOTUs). Tea plants (Camellia sect. Thea) form a group of morphologically similar species with significant economic value, providing the raw material for tea, which is the most popular nonalcoholic caffeine-containing beverage in the world. Taxonomic challenges have arisen from vague species boundaries in this group. Results Based on the most comprehensive sampling of C. sect. Thea by far (165 individuals of 39 morphospecies), we applied three de novo species delimitation methods (ASAP, PTP, and mPTP) using plastome data to provide an independent evaluation of morphology-based species boundaries in tea plants. Comparing MOTU partitions with morphospecies, we particularly tested the congruence of MOTUs resulting from different methods. We recognized 28 consensus MOTUs within C. sect. Thea, while tentatively suggesting that 11 morphospecies be discarded. Ten of the 28 consensus MOTUs were uncovered as morphospecies complexes in need of further study integrating other evidence. Our results also showed a strong imbalance among the analyzed MOTUs in terms of the number of molecular diagnostic characters. Conclusion This study serves as a solid step forward for recognizing the underlying species boundaries of tea plants, providing a needed evidence-based framework for the utilization and conservation of this economically important plant group.

Background: The era of high throughput sequencing offers new paths to identifying species boundaries that are complementary to traditional morphology-based delimitations. De novo species delimitation using traditional or DNA super-barcodes serve as efficient approaches to recognizing putative species (molecular operational taxonomic units, MOTUs). Tea plants (Camellia sect. Thea) form a group of morphologically similar species with significant economic value, providing the raw material for tea, which is the most popular nonalcoholic caffeine-containing beverage in the world. Taxonomic challenges have arisen from vague species boundaries in this group. Results: Based on the most comprehensive sampling of C. sect. Thea by far (165 individuals of 39 morphospecies), we applied three de novo species delimitation methods (ASAP, PTP, and mPTP) using plastome data to provide an independent evaluation of morphology-based species boundaries in tea plants. Comparing MOTU partitions with morphospecies, we particularly tested the congruence of MOTUs resulting from different methods. We recognized 28 consensus MOTUs within C. sect. Thea, while tentatively suggesting that 11 morphospecies be discarded. Ten of the 28 consensus MOTUs were uncovered as morphospecies complexes in need of further study integrating other evidence. Our results also showed a strong imbalance among the analyzed MOTUs in terms of the number of molecular diagnostic characters. Conclusion: This study serves as a solid step forward for recognizing the underlying species boundaries of tea plants, providing a needed evidence-based framework for the utilization and conservation of this economically important plant group. [ABSTRACT FROM AUTHOR]

In this study, the genome of an endemic Sulawesi’s plant, Medinilla tapete-magicum was sequenced using Illumina NextSeq 500 and assembled the whole chloroplast genome. Results showed that the cpGenome is 155,602 bp in size with typical quadripartite structure of a large single copy (LSC) region (85,409 bp), a short single copy (SSC) region (16,629 bp), and a pair of inverted repeats (IRs) regions (26,782 bp). The cpGenome is composed of 132 genes, which consists of 87 protein coding genes, 37 tRNAs, and 8 rRNAs. The sliding window analyses showed that psbB-psbH and ndhF-rpl32 can potentially be used as markers. Microsatellite motifs of mononucleotide A and T dominated in the cpGenome. The phylogenetic trees from the concatenated 76 shared protein coding gene sequences showed the Medinilla clade was monophyletic and M. tapete-magicum is a sister species in the SE Asian clade which contain M. magnifica and M. speciosa.

DNA barcoding has been widely used for herb identification in recent decades, enabling safety and innovation in the field of herbal medicine. In this article, we summarize recent progress in DNA barcoding for herbal medicine to provide ideas for the further development and application of this technology. Most importantly, the standard DNA barcode has been extended in two ways. First, while conventional DNA barcodes have been widely promoted for their versatility in the identification of fresh or well-preserved samples, super-barcodes based on plastid genomes have rapidly developed and have shown advantages in species identification at low taxonomic levels. Second, mini-barcodes are attractive because they perform better in cases of degraded DNA from herbal materials. In addition, some molecular techniques, such as high-throughput sequencing and isothermal amplification, are combined with DNA barcodes for species identification, which has expanded the applications of herb identification based on DNA barcoding and brought about the post-DNA-barcoding era. Furthermore, standard and high-species coverage DNA barcode reference libraries have been constructed to provide reference sequences for species identification, which increases the accuracy and credibility of species discrimination based on DNA barcodes. In summary, DNA barcoding should play a key role in the quality control of traditional herbal medicine and in the international herb trade.

DNA barcoding has been widely used for herb identification in recent decades, enabling safety and innovation in the field of herbal medicine. In this article, we summarize recent progress in DNA barcoding for herbal medicine to provide ideas for the further development and application of this technology. Most importantly, the standard DNA barcode has been extended in two ways. First, while conventional DNA barcodes have been widely promoted for their versatility in the identification of fresh or well-preserved samples, super-barcodes based on plastid genomes have rapidly developed and have shown advantages in species identification at low taxonomic levels. Second, mini-barcodes are attractive because they perform better in cases of degraded DNA from herbal materials. In addition, some molecular techniques, such as high-throughput sequencing and isothermal amplification, are combined with DNA barcodes for species identification, which has expanded the applications of herb identification based on DNA barcoding and brought about the post-DNA-barcoding era. Furthermore, standard and high-species coverage DNA barcode reference libraries have been constructed to provide reference sequences for species identification, which increases the accuracy and credibility of species discrimination based on DNA barcodes. In summary, DNA barcoding should play a key role in the quality control of traditional herbal medicine and in the international herb trade. [Display omitted] • Recent progress of DNA barcoding in herbal medicine was summarized. • Herbal identification entered into the post-era of DNA barcoding. • Future herbal identification will focus on studies at lower taxonomic levels. • Application of DNA barcoding will be extended to herbal mixtures and CPM. [ABSTRACT FROM AUTHOR]

Laportea bulbifera, a Miao medicine grown in karst areas, has exerted a unique curative effect on skin itching in the elderly, with an annual sales of > 100 million Yuan. Owing to the shortage of resources and large morphological variations in L. bulbifera, it is difficult to identify the species correctly using only traditional methods, which seriously affects the safety of drug usage for patients. This study obtained the complete high-quality L. bulbifera chloroplast (cp) genome, using second- and third-generation high-throughput sequencing. The cp genome was 149,911 bp in length, with a typical quadripartite structure. A total of 127 genes were annotated, including 83 protein-coding genes, 36 tRNA genes, and 8 rRNA genes. There was an inverted small single copy (SSC) structure in the L. bulbifera cp genome, one large-scale rearrangement of ~ 39 kb excised in the SSC and IR regions. The complete cp genome sequence is used as a potentially effective super-barcode and the highly variable regions (ycf1, matK, and ndhD) can be used as potentially specific barcodes to accurately distinguish L. bulbifera from counterfeits and closely related species. This study is important for the identification of L. bulbifera and lays a theoretical foundation for elucidating the phylogenetic relationship of the species. [ABSTRACT FROM AUTHOR]

The olive genus Olea includes c. 30–40 taxa in three subgenera (Olea, Tetrapilus, and Paniculatae) within the family Oleaceae. Historically, the Olea genus was classified into four groups that were overall well supported by reconstructed phylogenies, despite incomplete sampling of subgenus Tetrapilus and poor resolution within clades. These analyses also showed that the genus was not monophyletic. Reliable identification of Olea species is important for both their conservation and utilization of this economically important genus. In this study, we used phylogenomic data from genome skimming to resolve relationships within Olea and to identify molecular markers for species identification. We assembled the complete plastomes, and nrDNA of 26 individuals representing 13 species using next‐generation sequencing and added 18 publicly available accessions of Olea. We also developed nuclear SNPs using the genome skimming data to infer the phylogenetic relationships of Olea. Large‐scale phylogenomic analyses of 138 samples of tribe Oleeae supported the polyphyly of Olea, with Olea caudatilimba and Olea subgenus Tetrapilus not sharing their most recent common ancestor with the main Olea clade (subgenus Paniculatae and subgenus Olea). The interspecific phylogenetic resolution was poor owing to a possible rapid radiation. By comparing with the plastome data, we identified the markers ycf1b and psbE‐petL as the best Olea‐specific chloroplast DNA barcodes. Compared with universal barcodes, specific DNA barcodes and super‐barcode exhibited higher discriminatory power. Our results demonstrated the power of phylogenomics to improve phylogenetic relationships of intricate groups and provided new insights into barcodes that allow for accurate identification of Olea species. Highlights: Genus Olea was a polyphyletic group and had undergone rapid radiation.ycf1b and psbE‐petL were two Olea‐specific chloroplast DNA barcodes.Plastome sequence data had effective power to improve phylogenetic resolution and species discrimination. [ABSTRACT FROM AUTHOR]

Wuyi tea (Camellia. sinensis, Synonym: Thea Bohea L.) is recognized as the most prestigious oolong tea in China. For germplasm identification and protection, the complete chloroplast genomes of five classical Wuyi tea varieties were determined by next-generation sequencing. These chloroplast genomes showed highly conserved structures and are 157,024–157,126 bp in length, consisting of a pair of reverse repeats (IR) regions of 25,944–26,095 bp, one large single-copy (LSC) region of 86,594–86,859 bp, and one small single copy (SSC) region of 18,276–18,291 bp. A total of 137 genes were observed and overall GC contents were all about 37.3%. Phylogenetic analysis revealed Wuyi tea varieties did not cluster together, suggesting that these Wuyi tea varieties might have diverged early in their evolutionary history and the complete chloroplast genome could be used as a super-barcode to identify these varieties. This study will be valuable for future studies of evolution and intraspecific identification in Wuyi tea.

Abstract Background Although molecular analysis offers a wide range of options for species identification, a universal methodology for classifying and distinguishing closely related species remains elusive. This study validated the effectiveness of utilizing the entire chloroplast (cp) genome as a super-barcode to help identify and classify closely related species. Methods We here compared 26 complete cp genomes of ten Fritillaria species including 18 new sequences sequenced in this study. Each species had repeats and the cp genomes were used as a whole DNA barcode to test whether they can distinguish Fritillaria species. Results The cp genomes of Fritillaria medicinal plants were conserved in genome structure, gene type, and gene content. Comparison analysis of the Fritillaria cp genomes revealed that the intergenic spacer regions were highly divergent compared with other regions. By constructing the phylogenetic tree by the maximum likelihood and maximum parsimony methods, we found that the entire cp genome showed a high discrimination power for Fritillaria species with individuals of each species in a monophyletic clade. These results indicate that cp genome can be used to effectively differentiate medicinal plants from the genus Fritillaria at the species level. Conclusions This study implies that cp genome can provide distinguishing differences to help identify closely related Fritillaria species, and has the potential to be served as a universal super-barcode for plant identification.

Background: Although molecular analysis offers a wide range of options for species identification, a universal methodology for classifying and distinguishing closely related species remains elusive. This study validated the effectiveness of utilizing the entire chloroplast (cp) genome as a super-barcode to help identify and classify closely related species. Methods: We here compared 26 complete cp genomes of ten Fritillaria species including 18 new sequences sequenced in this study. Each species had repeats and the cp genomes were used as a whole DNA barcode to test whether they can distinguish Fritillaria species. Results: The cp genomes of Fritillaria medicinal plants were conserved in genome structure, gene type, and gene content. Comparison analysis of the Fritillaria cp genomes revealed that the intergenic spacer regions were highly divergent compared with other regions. By constructing the phylogenetic tree by the maximum likelihood and maximum parsimony methods, we found that the entire cp genome showed a high discrimination power for Fritillaria species with individuals of each species in a monophyletic clade. These results indicate that cp genome can be used to effectively differentiate medicinal plants from the genus Fritillaria at the species level. Conclusions: This study implies that cp genome can provide distinguishing differences to help identify closely related Fritillaria species, and has the potential to be served as a universal super-barcode for plant identification. [ABSTRACT FROM AUTHOR]

Main conclusion: The chloroplast genomes of the five Crataegus species were shown to have a conserved genome structure. Complete chloroplast genome sequences were more suitable than highly variable regions for the identification and phylogenetic analysis of Crataegus species. Hawthorn, which is commonly used as a traditional Chinese medicine, is one of the most popular sour fruits and has high economic value. Crataegus pinnatifida var. pinnatifida and C. pinnatifida var. major are frequently adulterated with other Crataegus species on the herbal medicine market. However, most Crataegus plants are difficult to identify using traditional morphological methods. Here, we compared five Crataegus chloroplast (CP) genomes comprising two newly sequenced (i.e., C. pinnatifida var. pinnatifida and C. pinnatifida var. major) and three previously published CP genomes. The CP genomes of the five Crataegus species had a conserved genome structure, gene content and codon usage. The total length of the CP genomes was 159,654–159,865 bp. A total of 129–130 genes, including 84–85 protein-coding genes, 37 tRNA genes and 8 rRNA genes, were annotated. Bioinformatics analysis revealed 96–103 simple sequence repeats (SSRs) and 48–70 long repeats in the five CP genomes. Combining the results of mVISTA and nucleotide diversity, five highly variable regions were screened for species identification and relationship studies. Maximum likelihood trees were constructed on the basis of complete CP genome sequences and highly variable regions. The results showed that the former had higher discriminatory power for Crataegus species, indicating that the complete CP genome could be used as a super-barcode to accurately authenticate the five Crataegus species. [ABSTRACT FROM AUTHOR]

Gardenia jasminoides is well distributed and planted in China because of high ornamental and medical applications in Rubiaceae. Therefore, aiming at studying the biodiversity and solar-related genes, we acquired its complete chloroplast genome. The chloroplast genome was 155,096 bp in length with typical circle structure, it presented an 85,409 bp large single-copy (LSC) region, an 18,103 bp small single-copy (SSC) region, and two 25,792 bp inverted repeat (IRs) regions. The overall GC content was 37.49%, SSC and IR components showed extreme GC percentages ranging from 31.53 to 43.18. A brief online annotation reported 125 CDSs, 8 rRNAs, and 33 tRNA. To our surprise, G. jasminoides was closer to Coffea canephora and Coffea arabica within Rubiaceae from phylogenetic analysis. This chloroplast genome announcement of the G. jasminoides could embody light on the artificial breeding and further researches in the genus Gardenia Ellis and recruit more studies in this family.

Wuyi tea (Camellia. sinensis, Synonym: Thea Bohea L.) is recognized as the most prestigious oolong tea in China. For germplasm identification and protection, the complete chloroplast genomes of five classical Wuyi tea varieties were determined by next-generation sequencing. These chloroplast genomes showed highly conserved structures and are 157,024–157,126 bp in length, consisting of a pair of reverse repeats (IR) regions of 25,944–26,095 bp, one large single-copy (LSC) region of 86,594–86,859 bp, and one small single copy (SSC) region of 18,276–18,291 bp. A total of 137 genes were observed and overall GC contents were all about 37.3%. Phylogenetic analysis revealed Wuyi tea varieties did not cluster together, suggesting that these Wuyi tea varieties might have diverged early in their evolutionary history and the complete chloroplast genome could be used as a super-barcode to identify these varieties. This study will be valuable for future studies of evolution and intraspecific identification in Wuyi tea. [ABSTRACT FROM AUTHOR]

The taxonomy and nomenclature of Dracaena plants are much disputed, particularly for several Dracaena species in Asia. However, neither morphological features nor common DNA regions are ideal for identification of Dracaena spp. Meanwhile, although multiple Dracaena spp. are sources of the rare traditional medicine dragon’s blood, the Pharmacopoeia of the People’s Republic of China has defined Dracaena cochinchinensis as the only source plant. The inaccurate identification of Dracaena spp. will inevitably affect the clinical efficacy of dragon’s blood. It is therefore important to find a better method to distinguish these species. Here, we report the complete chloroplast (CP) genomes of six Dracaena spp., D. cochinchinensis, D. cambodiana, D. angustifolia, D. terniflora, D. hokouensis, and D. elliptica, obtained through high-throughput Illumina sequencing. These CP genomes exhibited typical circular tetramerous structure, and their sizes ranged from 155,055 (D. elliptica) to 155,449 bp (D. cochinchinensis). The GC content of each CP genome was 37.5%. Furthermore, each CP genome contained 130 genes, including 84 protein-coding genes, 38 tRNA genes, and 8 rRNA genes. There were no potential coding or non-coding regions to distinguish these six species, but the maximum likelihood tree of the six Dracaena spp. and other related species revealed that the whole CP genome can be used as a super-barcode to identify these Dracaena spp. This study provides not only invaluable data for species identification and safe medical application of Dracaena but also an important reference and foundation for species identification and phylogeny of Liliaceae plants.

The taxonomy and nomenclature of Dracaena plants are much disputed, particularly for several Dracaena species in Asia. However, neither morphological features nor common DNA regions are ideal for identification of Dracaena spp. Meanwhile, although multiple Dracaena spp. are sources of the rare traditional medicine dragon's blood, the Pharmacopoeia of the People's Republic of China has defined Dracaena cochinchinensis as the only source plant. The inaccurate identification of Dracaena spp. will inevitably affect the clinical efficacy of dragon's blood. It is therefore important to find a better method to distinguish these species. Here, we report the complete chloroplast (CP) genomes of six Dracaena spp., D. cochinchinensis , D. cambodiana , D. angustifolia , D. terniflora , D. hokouensis , and D. elliptica , obtained through high-throughput Illumina sequencing. These CP genomes exhibited typical circular tetramerous structure, and their sizes ranged from 155,055 (D. elliptica) to 155,449 bp (D. cochinchinensis). The GC content of each CP genome was 37.5%. Furthermore, each CP genome contained 130 genes, including 84 protein-coding genes, 38 tRNA genes, and 8 rRNA genes. There were no potential coding or non-coding regions to distinguish these six species, but the maximum likelihood tree of the six Dracaena spp. and other related species revealed that the whole CP genome can be used as a super-barcode to identify these Dracaena spp. This study provides not only invaluable data for species identification and safe medical application of Dracaena but also an important reference and foundation for species identification and phylogeny of Liliaceae plants. [ABSTRACT FROM AUTHOR]

Gardenia jasminoides is well distributed and planted in China because of high ornamental and medical applications in Rubiaceae. Therefore, aiming at studying the biodiversity and solar-related genes, we acquired its complete chloroplast genome. The chloroplast genome was 155,096 bp in length with typical circle structure, it presented an 85,409 bp large single-copy (LSC) region, an 18,103 bp small single-copy (SSC) region, and two 25,792 bp inverted repeat (IRs) regions. The overall GC content was 37.49%, SSC and IR components showed extreme GC percentages ranging from 31.53 to 43.18. A brief online annotation reported 125 CDSs, 8 rRNAs, and 33 tRNA. To our surprise, G. jasminoides was closer to Coffea canephora and Coffea arabica within Rubiaceae from phylogenetic analysis. This chloroplast genome announcement of the G. jasminoides could embody light on the artificial breeding and further researches in the genus Gardenia Ellis and recruit more studies in this family. [ABSTRACT FROM AUTHOR]

More than 30 Ligularia Cass. (Asteraceae) species have long been used in folk medicine in China. Morphological features and common DNA regions are both not ideal to identify Ligularia species. As some Ligularia species contain pyrrolizidine alkaloids, which are hazardous to human and animal health and are involved in metabolic toxification in the liver, it is important to find a better way to distinguish these species. Here, we report complete chloroplast (CP) genomes of six Ligularia species, L. intermedia, L. jaluensis, L. mongolica, L. hodgsonii, L. veitchiana, and L. fischeri, obtained through high-throughput Illumina sequencing technology. These CP genomes showed typical circular tetramerous structure and their sizes range from 151,118 to 151,253 bp. The GC content of each CP genome is 37.5%. Every CP genome contains 134 genes, including 87 protein-coding genes, 37 tRNA genes, eight rRNA genes, and two pseudogenes (ycf1 and rps19). From the mVISTA, there were no potential coding or non-coding regions to distinguish these six Ligularia species, but the maximum likelihood tree of the six Ligularia species and other related species showed that the whole CP genome can be used as a super-barcode to identify these six Ligularia species. This study provides invaluable data for species identification, allowing for future studies on phylogenetic evolution and safe medical applications of Ligularia.

Keywords: Dracaena Vand. ex L.; chloroplast genome; identification; super-barcode; Liliaceae Dracaena Vand. ex L., chloroplast genome, identification, super-barcode, Liliaceae. [Extracted from the article]

More than 30 Ligularia Cass. (Asteraceae) species have long been used in folk medicine in China. Morphological features and common DNA regions are both not ideal to identify Ligularia species. As some Ligularia species contain pyrrolizidine alkaloids, which are hazardous to human and animal health and are involved in metabolic toxification in the liver, it is important to find a better way to distinguish these species. Here, we report complete chloroplast (CP) genomes of six Ligularia species, L. intermedia, L. jaluensis, L. mongolica, L. hodgsonii, L. veitchiana, and L. fischeri, obtained through high-throughput Illumina sequencing technology. These CP genomes showed typical circular tetramerous structure and their sizes range from 151,118 to 151,253 bp. The GC content of each CP genome is 37.5%. Every CP genome contains 134 genes, including 87 protein-coding genes, 37 tRNA genes, eight rRNA genes, and two pseudogenes (ycf1 and rps19). From the mVISTA, there were no potential coding or non-coding regions to distinguish these six Ligularia species, but the maximum likelihood tree of the six Ligularia species and other related species showed that the whole CP genome can be used as a super-barcode to identify these six Ligularia species. This study provides invaluable data for species identification, allowing for future studies on phylogenetic evolution and safe medical applications of Ligularia. [ABSTRACT FROM AUTHOR]

ABSTRACT DNA barcoding is currently a widely used and effective tool that enables rapid and accurate identification of plant species; however, none of the available loci work across all species. Because single-locus DNA barcodes lack adequate variations in closely related taxa, recent barcoding studies have placed high emphasis on the use of whole-chloroplast genome sequences which are now more readily available as a consequence of improving sequencing technologies. While chloroplast genome sequencing can already deliver a reliable barcode for accurate plant identification it is not yet resource-effective and does not yet offer the speed of analysis provided by single-locus barcodes to unspecialized laboratory facilities. Here, we review the development of candidate barcodes and discuss the feasibility of using the chloroplast genome as a super-barcode. We advocate a new approach for DNA barcoding that, for selected groups of taxa, combines the best use of single-locus barcodes and super-barcodes for efficient plant identification. Specific barcodes might enhance our ability to distinguish closely related plants at the species and population levels. [ABSTRACT FROM AUTHOR]

Wuyi tea ( Camellia. sinensis , Synonym: Thea Bohea L.) is recognized as the most prestigious oolong tea in China. For germplasm identification and protection, the complete chloroplast genomes of five classical Wuyi tea varieties were determined by next-generation sequencing. These chloroplast genomes showed highly conserved structures and are 157,024-157,126 bp in length, consisting of a pair of reverse repeats (IR) regions of 25,944-26,095 bp, one large single-copy (LSC) region of 86,594-86,859 bp, and one small single copy (SSC) region of 18,276-18,291 bp. A total of 137 genes were observed and overall GC contents were all about 37.3%. Phylogenetic analysis revealed Wuyi tea varieties did not cluster together, suggesting that these Wuyi tea varieties might have diverged early in their evolutionary history and the complete chloroplast genome could be used as a super-barcode to identify these varieties. This study will be valuable for future studies of evolution and intraspecific identification in Wuyi tea., Competing Interests: No potential conflict of interest was reported by the author(s)., (© 2022 The Author(s). Published by Informa UK Limited, trading as Taylor & Francis Group.)

The complete chloroplast sequence ofDendrobium officinale, an endangered and economically important traditional Chinese medicine, was reported and characterized. The genome size is 152,018 bp, with 37.5% GC content. A pair of inverted repeats (IRs) of 26,284 bp are separated by a large single-copy region (LSC, 84,944 bp) and a small single-copy region (SSC, 14,506 bp). The complete cp DNA contains 83 protein-coding genes, 39 tRNA genes and 8 rRNA genes. Fourteen genes contained one or two introns. [ABSTRACT FROM AUTHOR]

More than 30 Ligularia Cass. (Asteraceae) species have long been used in folk medicine in China. Morphological features and common DNA regions are both not ideal to identify Ligularia species. As some Ligularia species contain pyrrolizidine alkaloids, which are hazardous to human and animal health and are involved in metabolic toxification in the liver, it is important to find a better way to distinguish these species. Here, we report complete chloroplast (CP) genomes of six Ligularia species, L. intermedia , L. jaluensis , L. mongolica , L. hodgsonii , L. veitchiana , and L. fischeri , obtained through high-throughput Illumina sequencing technology. These CP genomes showed typical circular tetramerous structure and their sizes range from 151,118 to 151,253 bp. The GC content of each CP genome is 37.5%. Every CP genome contains 134 genes, including 87 protein-coding genes, 37 tRNA genes, eight rRNA genes, and two pseudogenes ( ycf1 and rps19 ). From the mVISTA, there were no potential coding or non-coding regions to distinguish these six Ligularia species, but the maximum likelihood tree of the six Ligularia species and other related species showed that the whole CP genome can be used as a super-barcode to identify these six Ligularia species. This study provides invaluable data for species identification, allowing for future studies on phylogenetic evolution and safe medical applications of Ligularia .