Molecular identification and quality analysis of Rhei Rhizoma based on chloroplast matK gene and UPLC / 药学学报

Rhei Rhizoma is commonly used as a traditional Chinese medicine with multiple botanical origins. Different botanical sources may have different pharmacological activities. The germplasm resources of commercial Rhei Rhizoma were determined based on the chloroplast gene matK, and the anthraquinone and free anthraquinone content was determined by UPLC to analyze quality of commercial Rhei Rhizoma. Eighty-nine commercial Rhei Rhizoma samples were collected from 40 cities in 27 provinces. DNA was extracted and the matK gene was amplified by PCR. Results indicated that the collected samples were from the same botanical origin, Rheum palmatum, and 8 genotypes were identified, including Rp1, Rp2, Rp3, Rp4, Rp5, Rp6, Rp10 and Rp12. Rp4 and Rp6, cultivated in Gansu, Sichuan and Yunnan provinces were the main circulating genotypes, representing 40.45% and 37.08% of the total samples, respectively. Phylogenetic tree analysis showed that the eight genotypes were mainly divided into two branches, of which the main genotypes Rp4 and Rp6 were in one branch. Genetic distance analysis indicated that the genetic separation of the eight genotypes was between 0.001 and 0.010. UPLC analysis indicated that 93.26% of the samples met the Pharmacopoeia standards. There were significant differences in the content of total anthraquinone and free anthraquinone among the samples, in which the difference in free anthraquinone was 1.01% and the difference in total anthraquinone content was 3.79%, indicating that the quality of commercial Rhei Rhizoma samples varies considerably. There was no significant difference in the content of total anthraquinone and free anthraquinone in commercial Rhei Rhizoma among different collection provinces and genotypes. This study will help guide the circulation of Rhei Rhizoma in the market and provides valuable insights for molecular identification and quality analysis of other traditional Chinese medicines.

Phylogenetic and Mutation Points Analysis of Sophora japonica cv. jinhuai Based on DNA Barcoding Sequences / 中国实验方剂学杂志

ObjectiveTo conduct phylogenetic analysis of internal transcribed spacer 2 （ITS2） and chloroplast gene segments including psbA-trnH， rbcL， and matK of Sophora japonica cv. jinhuai resource samples from different geographical sources， and to explore the genetic diversity of S. japonica cv. jinhuai. MethodPolymerase chain reaction （PCR） method was used to amplify the nucleic acid sequences of ITS2， psbA-trnH， rbcL， and matK of S. japonica cv. jinhuai. Neighbor joining （NJ） method was used to construct phylogenetic trees， and Kimura 2-Parameter （K2P） model was used to calculate the genetic distance of different samples. MEGA and BIOEDIT softwares were applied for mutiple alignment and analysis of ITS2， psbA-trnH， rbcL， and matK sequences of S. japonica cv. jinhuai. ResultThe lengths of ITS2 sequence were 278-279 bp. The lengths of psbA-trnH were 289 bp. The lengths of rbcL sequence were 673 bp. The lengths of matK sequences were 786-792 bp. There were 3 mutation points in ITS2 and psbA-trnH， no mutation point in rbcL， and 13 mutation points in matK. The samples of S. japonica cv. jinhuai were clustered into two groups based on the phylogenetic tree constructed by ITS2 sequences. The sample of seedling tree in Baibao was clustered into one group， while the other 25 samples were clustered into another group. For the psbA-trnH sequence， the success rate of PCR amplification of 28 samples of S. japonica cv. jinhuai was 100%. The 28 samples of S. japonica cv. jinhuai were clustered into three groups based on the clustering results of psbA-trnH sequence. The sample of seedling tree in Shaoshui was clustered into one group. The five samples of grafting tree and seedling tree in Miaotou， grafting trees in Jiantang， Wenqiao， and Daxu， and seeding tree in Xianshui were clustered into one group. The other 21 samples were clustered into another group. The 26 samples of S. japonica cv. jinhuai were clustered into two groups based on the phylogenetic tree constructed by matK sequences. The sample of seedling tree in Xianshui was clustered into one group， while the other 25 samples were clustered into another group. The clustering results of the rbcL sequence of S. japonica cv. jinhuai could not distinguish 28 resource samples. The phylogenetic tree constructed by the combined sequence of ITS2+psbA-trnH+rbcL+matK divided S. japonica cv. jinhuai resource samples into 4 groups. The 13 samples of seedling trees in Qiyang， Daoxian， Miaotou， Shaoshui， Shitang， Xianshui， Jiantang， and Xiangli， and grafting trees in Qiyang， Miaotou， Yongsui， Wenqiao， and Yangtang were clustered into one group. The sample of seedling tree in Wenqiao was clustered into one group. The sample of seedling tree in Daxu was clustered into one group. The remaining samples were clustered into another group. ConclusionPhylogenetic and mutation analysis provide the theoretic foundation to investigate the evolution of the resources of S. japonica cv. jinhuai， and evaluate their genuineness. The results of mutation points can be used to identify the related S. japonica cv. jinhuai resources. The findings of this study show that the combination of different gene sequences has an optimal effect on plant identification.

Molecular Identification of 22 Species of Lauraceae by DNA Barcoding / 中国实验方剂学杂志

Objective:DNA barcodes suitable for Lauraceae plants were screened，and 22 Lauraceae plants were identified and classified. Method:The DNA of 22 species of Lauraceae was extracted and amplified by polymerase chain reaction（PCR） with different DNA barcoding primers，followed by electrophoresis and sequencing. Codon Code Aligner was used to proofread，splice， and remove the forward and reverse primer sequences. The sequence was imported into DNAMAN for multiple sequence alignment，and the base mutation sites were analyzed. The Kimura 2-Parameter（K2P） distance of different plants was calculated by MEGA，and the variation degree was analyzed according to the genetic distance. The phylogenetic tree was constructed based on the adjacency method. Result:Three pairs of DNA barcoding primers were used to amplify and sequence the DNA of 22 species of Lauraceae，and 20 species were identified by comparing the specific base sites of gene sequences<bold>.</bold> Conclusion:Four <italic>Litsea</italic> plants could be identified by <italic>matK</italic>， three <italic>Phoebe</italic> plants except for<italic> Cinnamomum validinerve </italic>by<italic> rbcL</italic>， and 20 Lauraceae plants by the combination of<italic> matK</italic>， <italic>rbcL</italic>， and <italic>rpoB</italic>，which provided a theoretical basis for the identification and development of Lauraceae plants. Among them，<italic>matK</italic> was predominant in the identification of Lauraceae plants，and the results also showed that the combination of sequences for plant identification could achieve a better result in DNA barcoding. This study investigated the genetic relationship between Lauraceae plants at the molecular level，aiming at providing a basis for the investigation，cultivation，development，protection， and utilization of medicinal plant resources.

Phylogenetic relationships of plant species from the flowering desert of the Atacama Region / Relaciones filogenéticas de especies de plantas que crecen en el desierto florido de la Región de Atacama

Every 3 to 7 year angiosperms species of the flowering desert appear in the Atacama Region of Chile, as a result of the climatic phenomenon "El Niño". Our objective was to evaluate the universality of matK and rbcL barcode markers of these species, and validate their taxon through phylogenetic relationships. Argemone hunnemannii, Oenothera coquimbensis, Malesherbia humilis, Leucocoryne appendiculata, Loasa elongata, Nicotiana solanifolia, Stachys grandidentata, Aristolochia chilensis, Alstroemeria kingii and Adesmia eremophila, almost all classified as endemic to Chile, were collected in Pan de Azúcar and Llanos de Challe National Park (Atacama Region, Chile) at the end of October 2017. The phylogeny of these ten angiosperm species from the flowering desert was analyzed using rbcL and matK markers with the maximum likelihood and Bayesian inference methods. The results showed that 70% of the species can be distinguished with the matK or rbcL locus, however, 100% were distinguished using both loci. The phylogenetic results showed that the species formed clades with high reliability and high support with both the matK and rbcL genes, when comparing our results with sequences obtained from GenBank. The matK and rbcL genes are efficient markers for analyzing phylogenetic relationships and validating the taxonomy of flowering species.

Las especies de angiospermas del Desierto Florido de la Región de Atacama de Chile aparecen cada 3 a 7 años, influenciado por el fenómeno climático "El Niño". Nuestro objetivo fue evaluar la universalidad de los marcadores de código de barra matK y rbcL de estas especies, y validar su taxón por medio de relaciones filogenéticas. Las especies Argemone hunnemannii, Oenothera coquimbensis, Malesherbia humilis, Leucocoryne appendiculata, Loasa elongata, Nicotiana solanifolia, Stachys grandidentata, Aristolochia chilensis, Alstroemeria kingii y Adesmia eremophila son clasificadas la mayoría endémicas de Chile. Estas especies fueron colectadas en el Parque Nacional Pan de Azúcar y Llanos de Challe, Región de Atacama, Chile. La colecta se realizó a fines de octubre de 2017. Con los marcadores rbcL y matK se analizó la filogenia con los métodos máxima verosimilitud e inferencia bayesiana en diez especies de angiosperma del Desierto Florido. Los resultados mostraron que el 70% de las especies pueden ser distinguidas con un locus matK o rbcL, sin embargo, el 100% se distinguió usando ambos locus. Los resultados filogenéticos mostraron que las especies formaron clados con alta fiabilidad y alto soporte tanto con los genes matK y rbcL, al comparar con accesos de secuencias obtenidas de GenBank. Lo genes matK y rbcL son marcadores eficientes para analizar relaciones filogenéticas y validar el taxón de las especies de flor.

Molecular identification of Spatholobi Caulis and its adulterants based on DNA barcoding / 中草药

Objective: Molecular biology identification technology was used to screen the appropriate DNA barcoding to establish a fast and accurate method for identifying Spatholobi Caulis. Methods: A total of 72 samples of Spatholobi Caulis and its adulterants were collected, the sample DNA was extracted, the ITS2, matK, psbA-trnH, ITS, and rbcL sequences were amplified and sequenced, and the amplification success rate and sequencing success rate of each sequence were calculated. The alignment of all sequences was determined by MEGA 7.0 software, and the interspecies and intraspecific genetic distance of them were analyzed to evaluate the Barcoding gap, based on the Kimura-2-Parameter (K2P) two-parameter model. Phylosuite software was used to construct the ITS2, matK and psbA-trnH and multi-gene (I-M-P) phylogenetic tree. Results: The amplification success rate and sequencing success rate of ITS2 were the highest (100%), and the sequencing success rates of matK and psbA-trnH were 94.4% and 91.7% respectively, while rbcL and ITS were only 69.4% and 61.1%. Compared with other barcoding, ITS2 has obvious Barcoding gap, and there was less overlap tree showed that ITS2 and psbA-trnH can obviously cluster Spatholobi Caulis and its adulterants into different branches, while matK cannot separate Kadsurae Caulis and Schisandrae Sphenantherae Fructus. I-M-P phylogenetic tree had the same result as ITS2 and psbA-trnH. between species. Conclusion: The identification method based on ITS2 and supplemented by the psbA-trnH sequence can quickly and accurately identify S. Caulis and its adulterants, which can provide the basis for the safety and the accuracy of the clinical application.

Phylogenetic relationship analysis of common medicinal submetals and multiple real-time fluorescence PCR identification of Fritillariae Cirrhosae Bulbus / 中草药

Objective To investigate the feasibility of multiple real-time PCR for the detection of Fritillariae Cirrhosae Bulbus and adulterants. Methods Based on the analysis of interspecies variation, genetic distance and phylogenetic relationship of ITS, psbA-trnH, rbcL and matK gene sequences, the genes with fast evolution rate, big interspecies variation and small intraspecies variation were selected as target genes. Fritillariae Cirrhosae Bulbus and adulterants specific primers and Taqman probes were designed to establish a multiplex real-time PCR assay. Methods were evaluated by comparison of specificity, sensitivity and mixed sample detection and sequencing. Results The ITS and psbA-trnH mutations were higher than rbcL and matK, and rbcL and matK were significantly lower than ITS and psbA-trnH genes by genetic distance analysis. And the sensitivity of the establish multiple real-time PCR using ITS as the target gene was 0.01 ng. Four samples of adulterants were detected in 18 samples, and the results were consistent with the results of NJ tree clustering analysis. Conclusion Based on the IIS region sequence as the target gene to establish multiple real-time fluorescence PCR detection method can successfully identify Fritillariae Cirrhosae Bulbus and its counterfeit goods, which provides a new basis for the authenticity of identification.

Identification and analysis on medicinal plants of Labiatae from Emei Mountain Area Using ITS2 and matK sequences / 中草药

Objective: To evaluate the efficiency of ITS2 and matK DNA barcode for the identification the Labiatae medicinal plants in Emei Mountain. Methods: A total of 23 samples of Labiatae medicinal plants were harvested in Emei Mountain. The DNA was extracted and used for PCR to obtain the ITS2 sequences. Meanwhile, 54 ITS2 and 51 matK sequences of the medicinal plants in Labiatae were downloaded from Genbank. The interspecies and intraspecific genetic distance and sequence variation sites of all sequences were determined by MEGA 5.0 software. The Neighbor Joining (NJ) phylogenetic tree was constructed, and barcoding gap analysis was then performed. Results: The length of various ITS2 sequence was distributed from 190 to 237 bp, with GC content of 53%-73%. Moreover, significant barcoding gap was observed when comparing the distances, the recognition rate for plants of the Labiatae family was 94%.The barcoding gap of the matK sequence was not significant, there was obvious overlap, and the recognition rate for the Labiatae family was 96%. Conclusion: ITS2 has a better ability to identify Lamiaceae plants at the species level, but the matK sequence has a higher recognition rate for Lamiaceae plants. Therefore, the employment of ITS2 as core with matK as supplement was able to identify Lamiaceae plants quickly and accurately, and understand the genetic relationship between species accurately. This provides an important theoretical basis for the effective protection and rational development of the medicinal plant resources of the Labiatae plants in Emei Mountain.

DNA barcoding sequence analysis of Amomum tsao-ko germplasm resources in Yunnan Province / 中草药

Objective: To screen and evaluate DNA barcoding of Amomun tsao-ko populations in Yunnan. Methods: ITS, psbA-trnH, matK, rbcL, and ycf1 sequences were screened and evaluated using A. tsao-ko as samples. The samples of A. tsao-ko population were amplified and sequenced. The sequences were spliced with Genestar, and then processed with Mega for data processing. And A. tsao-ko diversity and identification were analyzed and discussed. Results: The length of the amplified fragments of primers ITS5 and ITS4 was approximately 520 bp; The length of the amplified fragments of the primers rbcLa-F and rbcLa-R was approximately 498 bp; The length of the amplified fragments of the primers ycf1-bF and ycf1-bR was approximately 800 bp; The length of the amplified fragments of the primers psbA-trnH-1F and psbA-trnH-1R was approximately 400 bp; The length of the amplified fragments of the primers matK-2F and matK-2R was approximately 470 bp. The success rate of amplification and sequencing was high, and most of the results were available. By analyzing the amplification results of ITS, psbA-trnH, matK and ycf1 sequences of A. tsao-ko, A. tsao-ko and other Amomum genus plants can be clearly distinguished; All samples of the ITS sequence were divided into MG5 white flower A. tsao-ko population and other populations; All samples of the psbA-trnH sequence were divided into MG5 white flower A. tsao-ko population, MG6 yellow flower A. tsao-ko population and other populations; All samples of the matK sequence were divided into MG6 A. tsao-ko population and other populations. The MG5 white flower A. tsao-ko sample failed to be amplified; All samples of the ycf1 sequence were divided into the MG6 yellow flower A. tsao-ko population and other populations, and the MG5 white flower A. tsao-ko population was clustered with the other 22 A. tsao-ko populations; The amplification of rbcL sequence was consistent for all samples. Conclusion: The ITS, matK, psbA-trnH and ycf1 sequences can accurately distinguish A. tsao-ko from other plants of Amomum genus; The sequence site variations were found in matK, psbA-trnH and ycf1 sequences of MG6. This research has contributed to the selection and breeding of A. tsao-ko varieties. ITS and psbA-trnHsequences can distinguish yellow flower and white flower of A. tsao-ko; There is no variation in the rbcL sequence of all samples of white and yellow flowers of A. tsao-ko, and Amomum tsao-ko and other plants of Amomum genus cannot be identified with the rbcL sequence, which can be discarded.

DNA barcoding identification of Dendrobium huoshanense and its adulterants / 中国中药杂志

This research preliminarily discusses the relations of Dendrobium system growth through chloroplast gene rbcL, matK and the nuclear genome ITS2. The DNA barcoding universal sequence for authentication of the Dendrobium medical plants was slected and the possibility concerning utilizing the DNA barcoding to distinguish the D. huoshanenseand its adulterants was analyzed. Using the universal primer pair of ITS2, rbcL and matK, series of extended sequencing in the Dendrobium were conducted. Meanwhile, considering the different index about amplification and sequencing success rate of each sequence, the intraspecific and interspecific aberrance, the employment of BioEdit and MEGA 5.0 software were applied to establish the systematic tree of the NJ molecular and evaluate the diversified authentication capability of various sequences. The consequence demonstrates that the sequence of ITS2 is not only the largest one both in the intraspecific and interspecific aberrance of the Dendrobium but also has obvious barcoding gap. Considering the few overlap between the intraspecific and interspecific aberrance and the highest percentage regarding the formation of unilateral branch in diverse Dendrobium which have different ITS2 sequences, it can differentiate the species of Dendrobium. Furthermore, due to the inferior success rate of the rbcL and thematK and the lower reliability of NJ systematic tree, the percentage of the unilateral species which are generated by the systematic tree of rbcL and matK sequences is deficient. Therefore, the sequence of ITS2 can serves as DNA barcoding to distinguish the D. huoshanense, the D. moniliform and the D. officinale.

Identification of DNA barcoding of common medicinal plants in Lamiaceae / 中草药

Objective: To screen a proper DNA barcoding suitable for common medicinal plants in Lamiaceae. Methods: The rDNA ITS sequence from 33 kinds of common medicinal plants in Lamiaceae and the chloroplast matK gene sequence from 40 kinds of common medicinal plants in Lamiaceae were amplified by PCR and sequenced. The interspecific and intraspecific Kimura 2-parameter distance (K2P) and the mutation sites in each sequence were calculated, and barcoding gap of sequence was evaluated by MEGA6.0. The phylogenetic trees were constructed on the basis of Neighbor-Joining method. Results: The total length of ITS sequence was 620-698 bp, the average G + C content was 62.8%, the chloroplast matK gene sequence length was 859-932 bp, the average G + C content was 34%, and the ITS sequence and matK gene sequence have obvious DNA barcoding gap, but the matK DNA barcoding gap was less than that of ITS gene sequence. From clustering analysis, the matK gene can identify the different species in Lamiaceae better than ITS sequence. Conclusion: matK sequence can be used as a preferred sequence to identify the species in Lamiaceae.

Molecular identification of six species in Aloe L. based on DNA barcoding / 中草药

Objective: To screen out a proper DNA barcode for suitable of six species in Aloe L. Methods: The genomic DNA from 18 samples of six species in Aloe L. was extracted by Plant Genomic DNA Kit, then nuclear ITS2 and the chloroplast psbA-trnH, rbcL, and matK of the samples were amplified using the universal primers and sequenced bidirectionally. The obtained sequences were assembled using Sequencher 4.1.4. The characteristics of four candidate DNA barcodes were analyzed and the Kimura 2-Parameter (K2P) distances were calculated based on the sequences using MEGA 5.0. DNA barcoding gaps were evaluated by the analysis of the intra-and inter-specific divergences. The phylogenetic trees were constructed on the basis of Neighbor-Joining method. Results: Totally 72 sequences of species in Aloe L. were acquired altogether, with each of ITS2, psbA-trnH, rbcL, and matK regions having 18 sequences respectively. The successful sequencing rate was 100% of all the four candidate barcodes. The alignment length and GC contents ranged from 255 to 723 bp and 30.6% to 68.2%. The maximum K2P intra-specific genetic distances were much smaller than the minimum inter-specific genetic distance of all samples in terms of psbA-trnH sequence and thus forming into a prominent barcoding gap. Due to some overlaps of intra-and inter-specific variation, there was no obvious barcoding gap in the aspect of ITS2, rbcL, and matK sequences. The phylogenetic tree constructed by psbA-trnH sequence was capable to identify the six species of Aloe L. while there existed fuzzy identification as to the other three candidate barcodes. Conclusion: DNA barcoding technology can identify species in Aloe L. accurately and psbA-trnH sequence can be the optimal barcode to identify the species of Aloe L.

Rapid PCR identification of Houttuynia cordata and Gymnotheca chinensis / 中草药

Objective: For rapid identification of Houttuynia cordata and Gymnotheca chinensis, the specific PCR for mutual authentication of them was established based on the SNPs in matK sequence. Methods: H. cordata and G. chinensis samples from different origins were collected, total DNA of all samples was extracted, and the matK gene was seqenced. SNPs in the matK sequences of all the samples were found by ClustulX 2.1 program. Primers for identifying H. cordata and G. chinens were designed according to the SNP site, and specific PCR method was established to identify them, for rapid detection by addition of SYBR Green I dye. In addition, constructing a multi-PCR reaction system, and then the PCR reaction system was optimized. Results: The band special for H. cordata (185 bp) and band special for G. chinensis (389 bp) were found using specific PCR reaction and multi-PCR reaction, and SYBR Green I dye can be used for rapid detection. Conclusion: The multi-PCR reaction system could be used to identify H. cordata and G. chinensis.

Applying Matk Gene for Identification of Liliopsida Plant Species from North Sulawesi Through Bold Systems.

DNA barcoding is a tool for species identification. For plant species identification, two of plastid genes (rbcL and matK) were used as standard barcodes. There are limitations of each gene marker but matK is considered to be the closest plant analogue to the CO1 animal barcode. As a mega-biodiversity country, Indonesia has many plant species used for ornamental and/or medical purposes. This study aimed to assess the identification of 15 known ornamental Liliopsida plant species in North Sulawesi using matK gene as a single marker. There were three possibilities result for species identification in this study: species level identification by top hit (1 specimen), species level identification by highest similarities (7 specimens), and genera level identification by highest similarities (7 specimens). Species identification by the highest similarity is reliable only when the result is identical with the sequence stored in the database.

Identification of plants in Mussaenda L. based on DNA barcoding / 中草药

This study aims at developing fast and accurate species identification methods for the plants of Mussaenda L. In the present study, DNA barcoding analysis was carried out on 89 individuals representing 20 species of Mussaenda in order to evaluate the performance of the four candidate barcoding loci (matK, rbcL, trnH-psbA, and ITS) and ITS2 region. Based on sequence similarity and Neighbor-joining (NJ) tree reconstruction, we detected inter-and intra-specific genetic distances using Kimura 2-parameter (K2P). Inter-specific genetic distance of species in Mussaenda was significantly higher than intra-specific genetic distance. The region of ITS2 showed the highest discrimination power among the independent sequences. Comparably high species discrimination power was also revealed by the matK and ITS data set. The candidate barcode of rbcL displayed the lowest identification rate among the others. However, each individual candidate barcode demonstrated significantly lower discrimination power than the barcode of combined data set. Comparable discrimination power was revealed between the two barcodes of combined sequences matK + rbcL + ITS and matK + rbcL + trnH-psbA + ITS, which showed the values around 77% and 75% based on sequence similarity and NJ tree method. Totally 15 species were identified based on NJ analysis of matK + rbcL + ITS. Consequently, the combined sequence of matK + rbcL + ITS provides an effective and fast tool for the identification and authentication of medicinal plant species in the genus Mussaenda L.

Identification of Gardenia Based on cpDNA Barcoding / 中国中医药信息杂志

Objective To test and eva1uate the abi1ity of three potential chloroplast DNA (cpDNA) barcoding sequences;To find new methods to identify the species of gardenia. Methods Three cpDNA sequences were amplified and sequenced by universal primers of matK, rbcL and psbA. By comparing PCR amplification efficiency, length, intra-and inter-specific divergence, and barcoding gap, BLAST and DNA MAN were used to evaluate these loci. Results The amplification efficiency of 5 samples from 3 gardenia species was 100%. Analysis of the intra-and inter-specific divergence of matK among the sequences showed that barcoding gap was superior to psbA and rbcL, with higher identification efficiency. Conclusion Gardenia jasminoides Ellis can be better identified by matK sequence.

Identification of traditional chinese medicine rubiae radix et and its adulterants using DNA barcodes / 中国药学杂志

OBJECTIVE: To identify traditional Chinese medicine Rubiae Radix et Rhizoma and its adulterants using DNA barcodes. METHODS: A total of 317 sequences of psbA-trnH, matK and rbcL from 13 species were analized. The intra- and inter-specific K2P genetic distances and neighbor-joining tree were calculated using MEGA5. 1 program. RESULTS: The DNAs were successfully extracted from 76 original plant samples. The amplification rates of psbA-trnH, matK and rbcL were 100%, 96%, and 99%, respectively. The adulterants could be identified from R. cordifolia by the single marker and the two combinations except for those adulterants in the Rubia genus. Fortunately, R. cordifolia could be identified from all the adulterants by psbA-trnH + matK + rbcL combination marker. The intra- and inter-specific K2P genetic distances of psbA-trnH + matK + rbcL were 0-0.001 4 and 0.000 7-0.630 3. R. cordifolia could be identified from alTthe adulterants by the psbA-trnH + matK + rbcL combination using NJ tree method. Among the 30 unidentified samples of Rubiae Radix et Rhizoma which were collected from medicinal herb markets, all three markers, including psbA-trnH, matK and rbcL, could be amplified from 22 samples. The 11 samples of Rubiae Radix et Rhizoma clustered with R. cordifolia and the others were divided into three clusters by the psbA-trnH + matK + rbcL combination using NJ tree method. CONCLUSION: psbA-trnH + matK + rbcL combination can be used as DNA barcode to identify R. cordifolia from adulterants.

DNA barcode identification of original species in Aesculus Linn / 中草药

Objective: To screen the DNA barcodes for identifying the species in genus Aesculus Linn. Methods: The PCR amplification and sequencing efficacy, intraspecific and interspecific variation, and identification efficiency of nuclear ITS, ITS2, chlroplast psbA-trnH, rbcL, and matK sequences from 42 samples of 10 species in genus Aesculus Linn. were investigated. The screened sequences were determined by barcoding gap and NJ tree clustering analysis. Results: The PCR amplification and sequencing efficacy of psbA-trnH were 100%, the interspecific minimum variation was larger than the intraspecific maximum variation, and psbA-trnH had the highest identification efficacy. The psbA-trnH sequence had less polymerization of intraspecific and interspecific variation. By constructing the NJ tree, thorough verifying the three original plants could be used to separate with other related species. Conclusion: The psbA-trnH sequence is a powerful, though not perfect, barcode for the identification of species in Aesculus Linn.

Universality Assessment of matK Primer Pairs in Seed Plants / 世界科学技术-中医药现代化

matK is one of the core DNA barcode markers for plant DNA barcode identification and its universality using single makers has been in controversy. However, the universalities of different matK primer pairs in same seed plant group (order) and same matK primer pairs in different seed plant groups (order) are lack of systematic research. In this study, we collected 14563 full-length matK sequences of 11429 species of 3292 genera in 239 families belonging to 36 orders in seed plants. The universalities of 13 matK primer pairs and its 78 primer com-binations have been assessed using bioinformatics methods. The results indicated that xf/5r, 1F/8R, 390F/1326R and 3F_KIM/1R_KIM were the four most universality primer pairs. The four markers' universalities were 91.18%, 84.65%, 79.81% and 80.94% respectively in all 11429 seed plants. The most universality primer pairs in different orders were different. For each order, the primer pair with maximum universality was different. the xf/5r was the basal primer pair for primer combination and 1F/8R, 1F/1R, M3/M4 and 3F_KIM/1R_KIM could be the complementary primer pairs. This study could be a valuable resource for the primer selection of the research DNA barcoding identification in seed plants.