Identification of Rosa laevigata Michx and Its Adulterants based on ITS2 DNA Barcode / 世界科学技术-中医药现代化

ABSTRACT

In order to verify the sstability and accuracy of DNA barcode technique, we chose Rosa laevigata Michx as study object. Genomic DNAs of 10 samples were extracted by modified CTAB method. ITS2 sequences were obtained by direct PCR sequencing; the other 6 sequences were obtained from GenBank. The sequences were assembled using the CodonCode Aligner. All of the 16 ITS2 sequences were aligned through Clustal-W and the genetic distances were computed using MEGA 5.0 in accordance with the Kimura 2-parameter (K-2-P) model. Results indicated that the lengths of ITS2 regions of R. laevigata ranged from 219 to 221 bp with two Poly C structure in it. The intra-specific genetic distances were smaller than inter-specific ones in ITS2 regions of R. laevigata. The NJ tree showed that R. laevigata and adulterants were divided into two clades, with 99%bootstrap value, showing good monophyly. So, ITS2 was considered a good marker to identify R. laevigata and its adulterants.