21种广东省珍稀保护药用植物的DNA条形码分析

DNA Barcode Analysis of 21 Rare and Protected Medicinal Plants in Guangdong Province

目的研究广东省珍稀濒危药用植物和国家重点保护药用植物的DNA条形码,构建条形码数据库,为广东省珍稀保护药用植物分子鉴定提供依据。方法野外采集目标植物叶片,硅胶干燥保存。采取试剂盒法提取样品基因组DNA,扩增ITS2、psbA-trnH、ITS、matK、rbcL、ycf1等6种DNA条形码,Sanger法进行双向测序。对双向拼接后的序列进行测序成功率、序列特征和BLAST鉴定情况统计。结果共搜集广东省珍稀保护药用植物21种182份,经测序获得条形码543条,各条形码在全部样品中的测序成功率比较:psbA-trnH>rbcL>ITS2>matK>ycf1>ITS,在物种水平的BLAST鉴定成功率比较:psbA-trnH>ITS>ycf1>matK>ITS2>rbcL。同时统计各条形码在蕨类、裸子及被子植物等不同分类阶元中的相应数据。结论综合测序成功率和BLAST鉴定成功率的结果,psbA-trnH条形码表现最好,为最适用于鉴定广东省珍稀保护药用植物的DNA条形码。同时,该研究构建了广东省珍稀保护药用植物DNA条形码数据库,为这些物种的分子鉴定奠定基础。

Objective This study evaluated the DNA barcodes of rare and endangered medicinal plants and medicinal plants under state protection in Guangdong province to select the suitable DNA barcodes for molecular identification,and constructed a local barcode database at the same time.Methods Plant leaves were collected in the wild and stored in silica gel for desiccation.Genomic DNA of plant sample was extracted using commercial kit and six DNA barcodes including ITS2,psbA-trnH,ITS,matK,rbcL and ycf1 were then amplified.The PCR products were purified and bi-directionally sequenced by Sanger method.Assembled sequences were evaluated by sequencing success rate,sequence characterization and BLAST identification success rate.Results A total of 182 samples of 21 rare and protected medicinal plants in Guangdong province were collected,and 543 barcodes were obtained.Of all the samples,order of the sequencing success rates of the barcodes were psbA-trnH>rbcL>ITS2>matK>ycf1>ITS;BLAST identification success rates at species level of each barcode were psbA-trnH>ITS>ycf1>matK>ITS2>rbcL.The corresponding data of barcodes in ferns,gymnosperms and angiosperms were also calculated.Conclusion Combining sequencing success rate and identification success rate,the psbA-trnH barcode performed the best among the six barcodes,which was considered the most suitable DNA barcode for identification of rare protected medicinal plants in Guangdong province.DNA barcode database of these plants were then constructed for their molecular identification.