[DNA Molecular Identification of Datura Medicinal Plants Using ITS2 Barcode Sequence]

To identify Datura medicinal plants in Solanaceae using DNA barcode technique and ITS2 sequence.

The second internal transcribed spacer (ITS2) of Datura and Nicotiana medicinal plant samples was amplified by PCR and sequenced. To expand scope of the research topic, ITS2 sequences of related species were downloaded from GenBank. Sequence assembly and consensus sequence generation were performed by CodonCode Aligner. All the ITS2 sequences in the study were compared and analyzed using software DNAMAN. The related data analysis and processing were performed using software MEGA 5. 10 and the NJ tree was constructed. The ITS2 secondary structure was predicted using ITS2 web server, and distinguishing differences of the ITS2 secondary structures of the samples.

In the cluster dendrogram, all of samples were clustered into three branches. The plants of Nicotiana were clustered into a single branch, and the same as Datura (Brugmansia) arborea, which is similar to the results of previous studies. These proved that Brugmansia and Datura belonged to two different genera. Other species of Datura were clustered into a branch where all the intra-species samples were clustered to one branch respectively and obviously distinguished, which showed monophyletic. Bootstrap support rates between each two branches were more than 95%.

ITS2 sequences have great potential in terms of systematics study and variety identification.