The Research Of DNA Barcoding In Medicinal Plants From Genus Ilex

Ilex L. is the4genus of Aquifoliaceae the only one which in China, in worldwide scale there is about more than400species. There are about200species in China, distributed in the provinces south of the Yangtze River. Ilex is a family which has various kinds of medicinal species, and it has experienced all kinds of variation for a long time because of the influences from natural hybrid, artificial selection and environmental condition changes. It is difficult to reveal the essence of their biology information by using traditional identification methods in Ilex. It is urging to explore a more efficient method to identify these closely related plants and different populations from other species.A comprehensive overview of the research of Ilex was built which included chemical composition, traditional efficacy and pharmacological activities thus can lead us develop a more rational standard of Ilexpharmaphylogeny relationship.DNA barcoding is a technology which used a relatively general, sufficient variation, easy expansion and relatively short DNA sequence to rapidly and accurately identification and recognition species. Firstly, our research selected ITS2, psbA-trnH, matK, ITS and trnL-F as candidate markers.40Ilex samples were amplified and sequenced by candidate markers, the amplified success rate results:ITS2> psbA-trnH> trnL-F> ITS> matK. The sequenced success rate result:ITS2> trnL-F> psbA-trnH> ITS>matK. The amplification and sequencing rates of ITS2were the highest and all above90%which can choose as best fragment to identification Ilex plants.Secondly, we have used ITS2sequence to identify closely related species in Ilex and judged the identification efficiency among closely related species and intra-specific samples. Extracted the total DNA from68samples in Ilex which included36species in Ilex, ITS2sequences were amplified and sequenced which we got64samples sequences. Data analysis showed that we got299bp of ITS2sequence after annotation which contained119informative sites. Using website predicted the secondary structure as an auxiliary reference tool.At last, NJ tree and MP tree were built by MEGA5software. Compared with traditional morphological classification, the results with the traditional taxonomy basically which can prove ITS2sequence can effectively utilized in Ilex medicinal plants identification.