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软件进行序列比对，进行种间序列差异分析比较，并构建Neighbor-jioning（NJ）系统进化树，预测ITS2二级结构。结果 在海桐皮2种基原中，刺桐的ITS2序列长度为232 bp，乔木刺桐的ITS2序列长度为230 bp，均为单倍型，可以明显区分；同时与其他刺桐属及易混品之间遗传距离较远。NJ树结果显示刺桐、乔木刺桐及其他易混品均单独聚为一支，表现出良好的单系性；依据ITS2二级结构，刺桐、乔木刺桐及其混伪品在4个螺旋区的茎环数目、大小、位置以及螺旋发出时的角度均有明显差异，可以直观地将刺桐与乔木刺桐，以及其与易混品进行区分。结论 ITS2序列作为DNA条形码能稳定、准确鉴别海桐皮药材，为保障安全用药提供了新的技术手段。

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.

R282.12

2019年医疗服务与保障能力提升补助资金“全国中药资源普查项目”（财社[2019]39号）；2018年中医药公共卫生服务补助专项“全国中药资源普查项目”（财社[2018]43号）；江苏省中药资源产业化过程协同创新中心项目（ZDXM-3-24）