Identification of Belamcandae Rhizoma, Iridis Tectori Rhizoma and Their Adulterants by ITS2 Sequence / 世界科学技术-中医药现代化

ABSTRACT

This study aimed to identify Belamcandae Rhizoma, Iridis tectori Rhizoma and their adulterants by ITS2 sequence. All the DNA samples of Belamcandae Rhizoma, Iridis tectori Rhizoma and their adulterants were extracted. The ITS2 sequence were succesfully amplified, and purified PCR products were sequenced. All the sequences were assembled using the CondonCode Aligner V3.7.1. The Kimura 2-Parameter (K2P) genetic distances and the Neighbor-Joining (NJ) phylogenetic tree were calculated by using MEGA5.1. Results indicated that the maximum intraspecific genetic distances of Belamcandae Rhizoma was 0, and the average GC content was 52.22%;the maximum intraspecific genetic distances of Iridis tectori Rhizoma was 0.004, and the average GC content was 67.87%. The maximum K2P intraspecific genetic distance of Belamcanda chinensis, Iris tectorum were both lower than the minimum interspecific genetic distance of adulterants. Additionally, the ITS2 sequences in each of these polytypic species were separated into pairs of divergent clusters in the NJ tree. The NJ tree based on ITS2 sequence indicated that Belamcandae Rhizoma, Iridis tectori Rhizoma and their adulterants could be distinguished clearly. It could be concluded that ITS2 barcode can be used to correctly identify Belamcandae Rhizoma, Iridis tectori Rhizoma from their adulterants, and ensure their safety in use.