[Identification of Dendrobii Caulis basing on ITS sequence].

Isolation of high-quality genomic DNA from dried and processed crude drug is the key for the DNA identification of Dendrobii Caulis. The DNA extract of Dendrobii Caulis was firstly compared using different method to isolate genomic DNA from dried and processed crude drug, including commercial DNA extracted kit and CTAB method. Using modified CTAB method (extracted from large samples), the genomic DNA was successfully isolated from Dendrobii Caulis, including Huangcao and Fengdou. The ITS regions were amplified using the purified DNA as template, and then cloned and sequenced. These ITS sequences were compared with data from Genbank database and our lab, 14 Dendrobium species and five similar species were identified from "Huangcao" and "Huangcao" slice, while six species and three similar species from "Fengdou" according to their sequence similarity. The study demonstrated that the dried Dendrobii Caulis could be identified using DNA molecular method, which could overcome deficiencies and limitations of traditional identification method and has a certain application prospects.