Molecular identification of Spatholobi Caulis and its adulterants based on DNA barcoding / 中草药

ABSTRACT

Objective: Molecular biology identification technology was used to screen the appropriate DNA barcoding to establish a fast and accurate method for identifying Spatholobi Caulis. Methods: A total of 72 samples of Spatholobi Caulis and its adulterants were collected, the sample DNA was extracted, the ITS2, matK, psbA-trnH, ITS, and rbcL sequences were amplified and sequenced, and the amplification success rate and sequencing success rate of each sequence were calculated. The alignment of all sequences was determined by MEGA 7.0 software, and the interspecies and intraspecific genetic distance of them were analyzed to evaluate the Barcoding gap, based on the Kimura-2-Parameter (K2P) two-parameter model. Phylosuite software was used to construct the ITS2, matK and psbA-trnH and multi-gene (I-M-P) phylogenetic tree. Results: The amplification success rate and sequencing success rate of ITS2 were the highest (100%), and the sequencing success rates of matK and psbA-trnH were 94.4% and 91.7% respectively, while rbcL and ITS were only 69.4% and 61.1%. Compared with other barcoding, ITS2 has obvious Barcoding gap, and there was less overlap tree showed that ITS2 and psbA-trnH can obviously cluster Spatholobi Caulis and its adulterants into different branches, while matK cannot separate Kadsurae Caulis and Schisandrae Sphenantherae Fructus. I-M-P phylogenetic tree had the same result as ITS2 and psbA-trnH. between species. Conclusion: The identification method based on ITS2 and supplemented by the psbA-trnH sequence can quickly and accurately identify S. Caulis and its adulterants, which can provide the basis for the safety and the accuracy of the clinical application.