大黄为常用多基原大宗药材，品种混乱，基原物种鉴定困难，给其药用安全及稳定性造成极大威胁。鉴于常用DNA条形码在大黄鉴定上的局限，申请人提出基于高通量叶绿体全基因组测序技术深入分析其高变区变异规律，解决大黄基原鉴定困难问题。本项目将重点研究：①利用Illumina结合PacBio测序技术获得全部大黄基原植物叶绿体全基因组；应用生物信息学方法分析叶绿体基因及间隔区片段变异率；筛查单核苷酸多态性位点，探索大黄叶绿体基因组碱基变化规律。②设计通用引物针对已收集的200余份大黄属样品评估扩增成功率；运用Wilcoxon秩和检验评估序列变异性，应用K2P模型及Blast1算法评估鉴定成功率；统计分析筛选获得高变分子标记，对其在大黄属植物中鉴定机理进行探讨。③建立鉴定大黄基原物种的快速检测技术体系。本研究将为多基原药材真伪鉴别及基原物种准确鉴定提供技术支持，为多基原药材精准用药提供理论依据。

Rhubarb is a commonly used multi-origin herb in China, while its clinical safety and effect have been threatened by the species confusion for the difficult in their identification. In the view of the universal DNA barcodes exhibited limitation on the identification of rhubarb, we intend to resolve the identification problem based on the chloroplast genome using high throughput sequencing technology. Three aspects following will be studied in this project: 1) Firstly, assembling the chloroplast genome sequences of the three rhubarb origin from the data sequenced using Illumina and PacBio, analyzing the variation of the genes and spacer regions, finding out the SNP sites, and investigating their nucleotide varying patterns. 2) Then, assessing the amplification success rate of the candidate sequences using universal primers toward the more than 200 collected samples, screening out the DNA barcode sequence suitable for the identification of rhubarb using Wilcoxon rank sum test, K2P model and Blast1 algorithm, and exploring its identification mechanism on these complex species of Rheum. 3) Finally, establishing a rapid identification technology system for the identification of rhubarb using rapid detection technology. The results of this research can provide a technical support and theoretical basis on the precision medicine, and the identification of authenticity and species origin for multi-origin herbs.