Development of germplasm identification markers and phylogenetics analysis of Ligusticum chuanxiong / 中草药

ABSTRACT

Objective: In this study, InDel markers were developed based on the high frequency Insertion/Deletion region of chloroplast genome of Ligusticum. Germplasm identification and phylogenetic development of Ligusticum chuanxiong and its common adulterants were studied with universal barcode. Methods: The 26 samples of L. chuanxiong and its common adulterants were amplified and sequenced by eight DNA universal barcodes ycf1, matK, ITS2, rpoC1, rbcL, rpoB, trnK, and psbA-trnH. Genetic distance statistics, barcoding gap and phylogenetic tree analysis methods were used to study the phylogenetic relationship and phylogeny of L. chuanxiong. At the same time, the evolutionary tree was constructed to study molecular identification of L. chuanxiong and its common adulterants. Results: The results showed that rbcL conserved site was the highest (97.32%) with the highest GC content (44.9%). The rbcL+rpoB fragment had the smallest average intraspecific genetic distance (0.002 5). The psbA-trnH sequence fragment had the largest average interspecific genetic distance (0.429 2). The trnK and rbcL+rpoB sequence had the highest interspecific genetic distance. The overlap of the "barcoding gap" region of psbA-trnH was the least. The species of L. chuanxiong and other adulterated species were not accurately identified by the eight pairs of DNA barcodes. The cluster analysis of 24 InDel markers could accurately identify genuine L. chuanxiong and classify the species of L. chuanxiong and its adulterants into four categories, one of which was genuine L. chuanxiong collected from Sichuan. Conclusion: The ability of InDel markers to identify authentic L. chuanxiong and its common adulterants was higher than that of common barcode. According to the above studies, it is found that it is impossible to distinguish L. chuanxiong and its common adulterants by the traditional DNA barcodes because of the large difference in genetic components. The newly developed InDel molecular markers can effectively identify L. chuanxiong and its commonly used adulterants, and provide an effective method for the genuineness of L. chuanxiong at molecular level.