Comparative plastomic analysis of three Bulbophyllum medicinal plants and its significance in species identification / 药学学报

italic>Bulbophyllum orchids are popular for its ornamental appearance and great medicinal values. However, there is still a lack of research on phylogenetic relationship and species identification for this genus. In this study, the plastome sequences of three medicinal Bulbophyllum orchids (Bulbophyllum affine, Bulbophyllum pectinatum, Bulbophyllum funingense) were sequenced and analyzed. After assembly and annotation, it was found that the plastomes of Bulbophyllum plants encoded a total of 108 genes, including 74 protein-coding genes, 30 tRNA genes and 4 rRNA genes. Based on the analysis of mVISTA and comparison between junctions, it was found that the plastome structure of Bulbophyllum orchids was relatively conserved, and the variation mainly existed in the non-coding regions. Phylogenetic analysis showed that Bulbophyllum orchids were closely related to Dendrobium orchids. SSR analysis of Bulbophyllum showed that most SSRs were located in the intergenic spacer and had the most single nucleotide repeats. In addition, based on the comparative analysis of non-coding sequences, a total of 10 high-variability sequences were screened out, among which the combination of five non-coding region sequences, including psbI-trnS, psbC-trnS, clpP-ex1-psbB, psaJ-rpl33, rpl33-rps18, had the highest sequence variability and could be used in the species identification study of medicinal plants of Bulbophyllum. In conclusion, this study provides a theoretical basis for phylogenetic relationship and species identification of Bulbophyllum orchids through the comparative analysis of plastome sequences of three medicinal plants of the genus Bulbophyllum.

Molecular identification of wild populations of Dendrobium officinale based on target region amplification polymorphism / 药学学报

In this study, TRAP molecular markers were used in identification of wild populations and hybrids of Dendrobium officinale, based on the sequences of genes encoding phosphoenolpyruvate carboxylase (PEPC), UDP-glucose pyrophosphorylase (UGP) and phenylalanine ammonia-lyase (PAL). Seven polymorphic target region amplification polymorphism (TRAP) primers were selected from 54 primer combinations and used in the identification of wild populations. Moreover, hybrids had female polymorphic bands, male polymorphic bands and heterozygous bands, which suggest that seven TRAP markers are able to identify the hybrids from their parents. Furthermore, the UPGMA dendrogram revealed that when sample from Guangnan in Yunnan province was used as one parent, reciprocal hybrids grouped with them in first, and then grouped with the other parent. The results indicated that the hybrids were closer to D. officinale from Guangnan population. This study identified the wild populations and hybrids of D. officinale by TRAP molecular markers, which is useful in selection of good varieties for artificial cultivation and early identification of hybrids. The study provides a method in the control of stability of germplasm and quality of D. officinale.

Evaluation of genetic diversity and population structure of Bletilla striata based on SRAP markers / 药学学报

Bletilla striata has been used as traditional Chinese medicine for several centuries. In recent years, the quality and quantity of wild B. striata plants have declined sharply due to habitat deterioration and human over-exploitation. Therefore, it is of great urgency to evaluate and protect B. striata wild plant resource. In this study, sequence-related amplified polymorphism (SRAP) markers were applied to assess the level and pattern of genetic diversity in twelve populations of B. striata. The results showed a high level of genetic diversity (PPB = 90.48%, H = 0.349 4, I = 0.509 6) and moderate genetic differentiation among populations (Gst = 0.260 9). Based on the unweighted pair-group method with arithmetic average (UPGMA), twelve populations gathered in three clusters. The cluster 1 included four populations. There are Nanjing, Zhenjiang, Xuancheng and Hangzhou. The seven populations which come from Hubei Province, Hunan Province, Jiangxi Province and Guizhou Province belonged to the cluster 2. The cluster 3 only contained Wenshan population. Moreover, Mantel test revealed significant positive correlation between genetic distances and geographic distances (r = 0.632 9; P B. striata.

Evaluation of genetic diversity and population structure of Bletilla striata based on SRAP markers / 药学学报

Bletilla striata has been used as traditional Chinese medicine for several centuries. In recent years, the quality and quantity of wild B. striata plants have declined sharply due to habitat deterioration and human over-exploitation. Therefore, it is of great urgency to evaluate and protect B. striata wild plant resource. In this study, sequence-related amplified polymorphism (SRAP) markers were applied to assess the level and pattern of genetic diversity in twelve populations of B. striata. The results showed a high level of genetic diversity (PPB = 90.48%, H = 0.349 4, I = 0.509 6) and moderate genetic differentiation among populations (G(st) = 0.260 9). Based on the unweighted pair-group method with arithmetic average (UPGMA), twelve populations gathered in three clusters. The cluster 1 included four populations. There are Nanjing, Zhenjiang, Xuancheng and Hangzhou. The seven populations which come from Hubei Province, Hunan Province, Jiangxi Province and Guizhou Province belonged to the cluster 2. The cluster 3 only contained Wenshan population. Moreover, Mantel test revealed significant positive correlation between genetic distances and geographic distances (r = 0.632 9; P < 0.000 1). According to the results, we proposed a series of conservation consideration for B. striata.

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.