Molecular Identification of Fritillariae Cirrhosae Bulbus and Its Adulterants
基于ITS2序列鉴定川贝母及其混伪品基原植物

To discriminate original plants of Fritillariae Cirrhosae Bulbus and its adulterants using ITS2 sequence as a DNA barcode. Fritillaria specimens of Fritillariae Cirrhosae Bulbus were collected. Their ITS2 sequences were extracted, amplified by PCR, and sequenced bidirectionally. Sequences were assembled by CodonCode Aligner. ITS2 sequences of adulterants were downloaded from GenBank. The intra-specific and inter-specific K-2-P distances of ITS2 sequences of the original plants were calculated, and N-J tree was constructed by MEGA V 4.1. Besides that, with the web tool established by Schultz etc., ITS2 secondary structures were predicted. The maximum intra-specific K-2-P distance was 0.0276, while the minimum inter-specific K-2-P distance was 0.0583. Different samples of Fritillariae Cirrhosae Bulbus and their original plants were gathered together and could be distinguished from their adulterants by N-J tree. Furthermore Fritillariae Cirrhosae Bulbus could also be differentiated obviously from its adulterants by their ITS2 secondary structure. ITS2 sequences exhibit their ability to discriminate Fritillariae Cirrhosae Bulbus and its adulterants. This barcode is an efficient molecular identification method.