[Identification of cimicifugae rhizoma and its adulterants using ITS2 sequence]

In order to identify Cimicifugae Rhizoma from its adulterants and to ensure its safe use, the internal transcribed spacer 2 (ITS2) sequence of Cimicifugae Rhizoma and its adulterants were amplified and bidirectionally sequenced by DNA barcoding technology. Sequence assembly and consensus sequence generation were performed by the CodonCode Aligner V3.7.1. The genetic distances were computed by MEGA 5.0. Identification analyses were performed using neighbor-joining (NJ) methods. The length of ITS2 sequence of the three origin plants of Cimicifugae Rhizoma include Cimicifuga heracleifolia, C. foetida, C. dahurica was 217, 219 and 219 bp, respectively. Their intraspecific genetic distance was much lower than the interspecific genetic distance with their closely related species. The NJ tree of ITS2 indicated that the three origin plants of Cimicifugae Rhizoma formed a monophyletic clade, Cimicifugae Rhizoma and its adulterants could be distinguished clearly. The authors proposed that ITS2 sequence was suitable for the authentication of Cimicifugae Rhizoma and its adulterants.