OBJECTIVE To develop a DNA authenticity identification kit of Gastrodia elata that combined DNA extraction technology with PCR technology, and to evaluate the performance of the kit methodologically.

METHODS The ITS2 sequences of Gastrodia elata and its common forgeries, such as amabilis root, dahlia tuber and potato, were found by the National Center for Biotechnology Information(NCBI). DNAMAN was used for multi-sequence alignment, and NCBI-primer-blast was used to design specific primers of Gastrodia elata. Improved DNA extraction method to ensure efficient extraction of authentic Gastrodia elata and its common forgeries genomic DNA, UV spectrophotometry was used to measure the concentration and purity. The PCR reaction system was optimized, the composition and reaction conditions of the kit were determined, and the commercially available gastrodia elata samples were randomly sampled.

RESULTS The DNA purity OD260/OD280 values of the samples extracted by the developed kit were (1.87±0.13). The minimum detection limit was 10 ng·μL⁻¹, and the result of repeated detection was the same for 3 times. Repeated freezing and thawing for 5, 10, 15, 20 times had no effect on the detection effect, and it could be stored at −20℃ for 1 year, among 10 commercially available gastrodia elata samples tested, 7 were authentic and 3 were counterfeit.

CONCLUSION The DNA authenticity test kit is highly specific, sensitive, reproducible and stable, and the test results are accurate, it is suitable for the rapid identification of asparagus and its common forgeries.