Phylogeography of Paris poliphylla var. yunnanensis based on chloroplast gene trnL-trnF sequences / 中国中药杂志

Phylogeography is a research hotspot in the field of the genetic diversity and core germplasm construction of endangered rare plants. Paris polyphylla var. yunnanensis is a rare plant species mainly distributed in China. Wild individuals have been overexploited for the last few decades because of increasing demand for such medicines. Therefore, it is great significance to study the phylogeography of P. poliphylla var. yunnanensis based on chloroplast gene trnL-trnF sequences. In this study, chloroplast genes trnL-trnF were used in the phylogeography analysis of 15 wild and 17 cultivated populations of P. polyphylla var. yunnanensis. This study revealed that based on the results of neutrality tests and mismatch analysis, the rapid expansion of wild population has not been detected in P. polyphylla var. yunnanensis. After aligning and sorting the obtained cpDNA sequences, a total of 15 haplotypes were detected in all 32 populations. One haplotype was unique to the wild population, and 5 haplotypes were unique to the cultivated population. It can be seen that the haplotype richness of cultivated population was higher than that of wild population. The wild populations of P. polyphylla var. yunnanensis were divided into two groups according to evolutionary relationship of haplotypes and distribution map of haplotypes. The haplotype of branch Ⅰ was mainly distributed in Guizhou, and the haplotype of branch Ⅱ was located in Yunnan and Huidong, Sichuan. Therefore, it's speculated that Guizhou and the west Yunnan region may be glacial refuge in the evolutionary history of wild populations of P. polyphylla var. yunnanensis, and in order to protect the wild resources more effectively, wild populations of P. polyphylla var. yunnanensis in these two areas should be included in the protection zone.

Applylication of new type combined fragments: nrDNA ITS+ nad 1-intron 2 for identification of Dendrobium species of Fengdous / 药学学报

In this study, 17 kinds of Dendrobium species of Fengdous including 39 individuals were collected from 4 provinces. Mitochondrial gene sequences co I, nad 5, nad 1-intron 2 and chloroplast gene sequences rbcL, matK amd psbA-trnH were amplified from these materials, as well as nrDNA ITS. Furthermore, suitable sequences for identification of Dendrobium species of Fengdous were screened by K-2-P and P-distance. The results showed that during the mentioned 7 sequences, nrDNA ITS, nad 1-intron 2 and psbA-trnH which had a high degree of variability could be used to identify Dendrobium species of Fengdous. However, single fragment could not be used to distinguish D. moniliforme and D. huoshanense. Moreover, compared to other combined fragments, new type combined fragments nrDNA ITS+nad 1-intron 2 was more effective in identifying the original plants of Dendrobium species and could be used to identify D. huoshanense and D. moniliforme. Besides, according to the UPGMA tree constructed with nrDNA ITS+nad 1-intron 2, 3 inspected Dendrobium plants were identified as D. huoshanense, D. moniliforme and D. officinale, respectively. This study identified Dendrobium species of Fengdous by combined fragments nrDNA ITS+nad 1-intron 2 for the first time, which provided a more effective basis for identification of Dendrobium species. And this study will be helpful for regulating the market of Fengdous.

Sequence analysis and identification of a chloroplast matK gene in Rhei Rhizoma from different botanical origins / 药学学报

Rhei Rhizoma is a Chinese medicine with multiple botanical origins. There is a problem to identify it with conventional methods. To compare the characteristics of chloroplast matK gene sequences of different Rheum species and authenticate inspected species, the matK gene sequences of different species from different origins were amplified, cloned, and sequenced. Genomic DNA of Rheum plants was extracted using modified DNA extracted Kit and matK gene sequences were analyzed by ContingExpress, DNAman and MEGA5.0. The length of matK gene sequences of Rheum palmatum, R. tanguticum and R. officinale were 1 518 bp containing 57 variable loci. According to the mutation sites, R. palmatum, R. tanguticum and R. officinale were divided into different genotypes separately. Based on the established method according to the loci 587, 707, 838, we successfully identified the genuine Rheum species from its adulterants.

High-throughput pyrosequencing of the complete chloroplast genome of Magnolia officinalis and its application in species identification / 药学学报

Chloroplast genome sequences have comprehensive application prospects in DNA barcoding and chloroplast engineering in traditional Chinese medicine. The complete chloroplast genome of Magnolia officinalis sequenced by high-throughput pyrosequencing and a sequencing procedure was established. Fourteen contigs were obtained after de nove assembly. The sequencing percent of coverage was 99.99%. The chloroplast genome is 160 183 bp in size, and has a typical quadripartite structure with the large (LSC, 88 210 bp) and small copy (SSC, 18 843 bp) regions separated by two copies of an inverted repeat (IRs, 26 565 bp each). chloroplast genes were successfully annotated, of which 17 genes located in each IR region. The chloroplast genome features in Magnolia officinalis are nearly identical to those from other Magnoliid chloroplast genomes. Phylogenetic analyses were performed based on 81 shared coding-genes for a total of 9 Magnolia samples of 5 closely related species. Results showed that distinguishing among species was generally straightforward at the species and population level. This study confirmed the effectiveness of our chloroplast genome sequencing procedure. The chloroplast genome can provide distinguishing differences to help identify Magnolia officinalis and its closely related plants.

Comparison of DNA barcoders in identifying medicinal materials / 中国中药杂志

The DNA barcoding of traditional Chinese medicine was summarized in this article. Based on analyzing a number of research findings, the authors discussed the possibility of nuclear DNA sequence and chloroplast genes in identifying medicinal materials. ITS was considered to evolve faster, which was used for plant molecular systematics analysis and species identification,while ITS2 was more suitable to identify medicinal materials. So, it is important that we should select suitable DNA sequences as barcodes based on the objective of a study. With the cost reduction of sequencing, identifying medicinal materials by cp-genome barcoding would be applied broadly and effectively in the future.

Analysis and authentication of chloroplast matK gene sequences of Herba Dendrobii / 药学学报

To compare the characteristic of chloroplast matK gene sequences of different Herba Dendrobium species and to authenticate inspected species, the matK gene sequences of 12 species (including 22 materials) and outgroup were amplified, cloned, and sequenced. Genomic DNA of Dendrobium plants was extracted using modified cetyltrimethyl ammonium bromide (CTAB) method. The matK gene sequences were about 1 410 bp in length. The variable sites were 51 while the parsim-informative sites were 11. There were nucleotides insertions and deletions in some species, in addition to transitions and transversions, such as in D. denneanum and D.chrysotoxum. Interspecies and different populations (varieties) of Dendrobium could be distinguished on phylogeny tree. The average genetic distance was 0.008, and the maximal and minimal genetic distances between Dendrobium species were 0.014 and 0.003, respectively. There were 8-20 variable sites between Dendrobium species. The genetic distance between populations (varieties) was 0.001, and there were 1-5 variable sites. Moreover, the 4 inspected materials were successfully authenticated. The database of chloroplast matK gene sequences of 12 species of Herba Dendrobii and inspected species could be used for the molecular authentication between Dendrobium species and populations. The matK gene sequence could be used as molecular maker for authentication of Herba Dendrobium.