基于ITS2序列的海桐皮及其混伪品DNA分子鉴定

目的 应用ITS2条形码技术,对海桐皮Erythrinae Cortex及其混伪品进行分子鉴定.方法 通过提取31份海桐皮药材基原植物刺桐E.variegata、乔木刺桐E.arborescens及其混伪品的基因组DNA,扩增ITS2序列并测序;同时从GenBank下载混伪品序列15种38条,运用MEGA 7.0软件进...

Molecular identification of Erythrinae Cortex and its adulterants based on ITS2 sequence

Objective ITS2 barcoding was used to discriminate Erythrinae Cortexi and its adulterants in order to provide a new method for the identification of Erythrinae Cortex. Methods The total genomic DNAs were extracted from 31 samples of Erythrina variegata var. orientalis, E. arborescens and its adulterants. The ITS2 sequences of these samples were amplified and bidirectional sequenced by PCR. The obtained sequences were submitted to the GenBank and the ITS2 sequences of 38 samples belonging to 15 species were downloaded from the GenBank. Genetic distance, neighbor joining (NJ) phylogenetic tree and secondary structures of ITS2 sequences were analyzed by using MEGA 7.0. Results We foung the maximum intraspecific genetic distance (K2P distance) was much smaller than the minimum interspecific genetic distance between E. variegata var. orientalis, E. arborescens and its adulterants. And the NJ tree showed that E. variegata var. orientalis, E. arborescens and its adulterants could be distinguished obviously, which showed high monophyly. In addition, comparing the secondary structure of ITS2 among Erythrinae Cortexi and its adulterants, it was found that there were significant differences in the number, size, position of loop, and the angle of helix exsertion. Conclusion ITS2 sequences, as a DNA barcode, can stably and accurately distinguish Erythrinae Cortex from its adulterants and it can also provide a new technique to ensure the clinical safety in utilization of Chinese materia medica.