DNA barcoding analysis of Schisandra chinensis based on ITS sequences
Based on the internal transcribed spacer(ITS)barcode sequences of Schisandra chinensis,this study explored the identification method of S.chinensis plants,providing reference for the identification and standardized cultivation of the source of this medicinal material.A total of 16 samples were collected in this study,and genomic DNA was extracted from the samples,followed by PCR amplification of the ITS sequence and bidirectional sequencing.After sequence assembly using SeqMan,the sequences were analyzed and aligned using MEGA11 software,K2P genetic distances were calculated,and a neighbor-joining(NJ)tree was constructed to establish the phylogenetic relationship.The results showed that the ITS sequences of the 16 samples in the study area had small structural differences and similar nucleotide sequences,with 1 variant site found in 2 samples;combining the genetic distances and NJ clustering tree results,all S.chinensis samples in the study area clustered together,forming a clade with the S.chinensis samples from GenBank,while the Kadsura samples formed an outgroup clade with a high support rate,with no clear differences within the species,allowing them to be distinguished from closely related species of Schisandra.DNA barcode technology based on the ITS sequence can differentiate and identify S.chinensis and its congeneric plants.