Analysis of fungal diversity on the surface of Armeniacae Semen Amarum using a DNA metabarcoding technique / 药学学报

Medicinal and edible Armeniacae Semen Amarum (ASA) is susceptible to fungal contamination because it is rich in oil and other nutrients. In this study, the fungal community diversity in ASA samples was analyzed based on a DNA metabarcoding technique to provide evidence for its safe use. Twelve batches of ASA samples samples from four medicinal material markets and three processing approaches were collected. Total DNA was extracted, the ITS2 sequences were amplified, and high-throughput sequencing was performed using the Illumina MiSeq PE300 platform. The results show that Ascomycota was the most dominant fungus in ASA samples. The predominant genus in sample SW1_P was Diutina, whereas the most predominant genus in the other samples was Aspergillus. Three harmful fungi were identified, namely, Aspergillus flavus, Wallemia sebi, and Rhizopus arrhizus. In addition, significant differences were observed in the relative abundance of Botryosphaeriales and Alternaria in ASA samples from different collection sites. Meanwhile, there were significant differences in the relative abundance of Hypocreales and Cladosporium in ASA samples from different processing approaches. In summary, the DNA metabarcoding technique can effectively clarify the fungal community diversity and quickly detect potential toxigenic fungi in ASA samples, thus providing a warning for mycotoxin contamination.

Identification of Bupleurum chinense and B. longiradiatum based on ITS2 barcode / 中国中药杂志

In this study, ITS2 barcode was used to identify Bupleurum chinense and B. longiradiatum. The ITS2 regions of 48 samples were amplified and sequenced. The sequences obtained above were aligned and the K2P distances were calculated. We used three methods, BLAST1, nearest distance and phylogenetic tree (NJ-tree), to test the identification ability. The results showed that the maximum intraspecific genetic distance of B. chinense was 0.013, and the minimum interspecific genetic distance between B. chinense and B. longiradiatum was 0.049. The NJ-tree can easily identify B. chinense and B. longiradiatum. Therefore, the ITS2 barcode is suitable to identify B. chinense and B. longiradiatum.

Identification of albiziae cortex, albiziae flos and their adulterants using ITS2 barcoding / 中国中药杂志

The ITS2 barcode was used to accurately identify Albiziae Cortex, Albiziae Flos and their adulterants in this study. A total of46 samples from Albiziae Cortex, Albiziae Flos and their adulterants were collected. The ITS2 regions were amplified and sequenced. Sequences were assembled using the CodonCode Aligner. The genetic distances of ITS2 region were calculated using MEGA 5.0. BLAST1, nearest distance and phylogenetic tree (NJ-tree) methods were used to assess the identification efficiency of the ITS2 barcode. The results revealed that the intraspecific genetic distances of Albizia julibrissin were lower than the interspecific genetic distances between A. julibrissin and its adulterants. The identification efficiency of ITS2 barcode using BLAST1 was 100%. The NJ-tree showed that A. julibrissin and their adulterants can be easily differentiated according to their monophyly. The ITS2 barcode is suitable to be as a barcode to identify Albiziae Cortex, Albiziae Flos and their adulterants.

Molecular identification of Corni Fructus and its adulterants by ITS/ITS2 sequences / 中国天然药物

UNLABELLED@#The DNA barcoding method was used to accurately and rapidly identify Corni Fructus and its adulterants.@*METHODS@#Genomic DNA extracted from Corni Fructus and its adulterants were used as templates. The ITS (internal trascribed spacer) regions were amplified using polymerase chain reaction. Sequence assembly was performed using CodonCode Aligner V 3.5.4. Genetic distances were computed using MEGA V 5.0. Species identification was conducted using neighbor-joining (NJ) trees.@*RESULTS@#The ITS sequence length of Corni Fructus was 659 bp. The average intra-specific genetic distance of Corni Fructus was 0.005, markedly lower than the inter-specific genetic distance between Corni Fructus and its adulterants (0.357). The ITS2 sequence length of Corni Fructus was 250 bp. No variation was found among the different samples. The interspecific genetic distance of ITS2 between Corni Fructus and its adulterants was 0.571. NJ trees and BLAST results indicated that Corni Fructus and its adulterants can be easily differentiated with monophyly.@*CONCLUSION@#ITS/ITS2 regions can accurately and efficiently distinguish Corni Fructus and its adulterants. In addition, the results not only established the foundation for the clinical safety in the utilization of Corni Fructus, but also provided reference for molecular identification of other Chinese herbal medicine and Chinese herbal pieces.

Principles for molecular identification of traditional Chinese materia medica using DNA barcoding / 中国中药杂志

Since the research of molecular identification of Chinese Materia Medica (CMM) using DNA barcode is rapidly developing and popularizing, the principle of this method is approved to be listed in the Supplement of the Pharmacopoeia of the People's Republic of China. Based on the study on comprehensive samples, the DNA barcoding systems have been established to identify CMM, i.e. ITS2 as a core barcode and psbA-trnH as a complementary locus for identification of planta medica, and COI as a core barcode and ITS2 as a complementary locus for identification of animal medica. This article introduced the principle of molecular identification of CMM using DNA barcoding and its drafting instructions. Furthermore, its application perspective was discussed.

Discussion on the botanical origin of Isatidis radix and Isatidis folium based on DNA barcoding / 药学学报

This paper aimed to investigate the botanical origins of Isatidis Radix and Isatidis Folium, and clarify the confusion of its classification. The second internal transcribed spacer (ITS2) of ribosomal DNA, the chloroplast matK gene of 22 samples from some major production areas were amplified and sequenced. Sequence assembly and consensus sequence generation were performed using the CodonCode Aligner. Phylogenetic study was performed using MEGA 4.0 software in accordance with the Kimura 2-Parameter (K2P) model, and the phylogenetic tree was constructed using the neighbor-joining methods. The results showed that the length of ITS2 sequence of the botanical origins of Isatidis Radix and Isatidis Folium was 191 bp. The sequence showed that some samples had several SNP sites, and some samples had heterozygosis sites. In the NJ tree, based on ITS2 sequence, the studied samples were separated into two groups, and one of them was gathered with Isatis tinctoria L. The studied samples also were divided into two groups obviously based on the chloroplast matK gene. In conclusion, our results support that the botanical origins of Isatidis Radix and Isatidis Folium are Isatis indigotica Fortune, and Isatis indigotica and Isatis tinctoria are two distinct species. This study doesn't support the opinion about the combination of these two species in Flora of China.