Testing four proposed barcoding markers for the identification of species within Ligustrum L.(Oleaceae)  

作　　者：Jing GU jun-Xia SU Ruo-Zhu LIN Rui-Qi LI Pei-Gen XIAO 

机构地区：[1]Institute of Medicinal Plant Development, Chinese Academy of Medical Sciences ＆ Pelting Union Medical College, Beijing 100193, China [2]State Key Laboratory of Systematic and Evolutionary Botany, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China

出　　处：《Journal of Systematics and Evolution》2011年第3期213-224,共12页植物分类学报（英文版）

基　　金：supported by Large-scale Scientific Facilities of the Chinese Academy of Sciences (grant no. 2009-LSF-GBOWS-01)

摘　　要：DNA barcoding is a biological technique that uses short and standardized genes or DNA regions to facilitate species identification. DNA barcoding has been used successfully in several animal and plant groups. Ligustrum （Oleaceae） species occur widely throughout the world and are used as medicinal plants in China. Therefore, the accurate identification of species in this genus is necessary. Four potential DNA barcodes, namely the nuclear ribosomal internal transcribed spacer （ITS） and three chloroplast （cp） DNA regions （rbcL, matK, and trnH-psbA）, were used to differentiate species within Ligustrum. BLAST, character-based method, tree-based methods and TAXONDNA analysis were used to investigate the molecular identification capabilities of the chosen markers for discriminating 92 samples representing 20 species of this genus. The results showed that the ITS sequences have the most variable information, followed by trnH-psbA, matK, and rbcL. All sequences of the four regions correctly identified the species at the genus level using BLAST alignment. At the species level, the discriminating power of rbcL, marK, trnH-psbA, and ITS based on neighbor-joining （NJ） trees was 36.8%, 38.9%, 77.8%, and 80%, respectively. Using character-based and maximum parsimony （MP） tree methods together, the discriminating ability of trnH-psbA increased to 88.9%. All species could be differentiated using ITS when combining the NJ tree method with character-based or MP tree methods. Overall, the results indicate that DNA barcoding is an effective molecular identification method for Ligustrum species. We propose the nuclear ribosomal ITS as a plant barcode for plant identification and trnH-psbA as a candidate barcode sequence.DNA barcoding is a biological technique that uses short and standardized genes or DNA regions to facilitate species identification. DNA barcoding has been used successfully in several animal and plant groups. Ligustrum （Oleaceae） species occur widely throughout the world and are used as medicinal plants in China. Therefore, the accurate identification of species in this genus is necessary. Four potential DNA barcodes, namely the nuclear ribosomal internal transcribed spacer （ITS） and three chloroplast （cp） DNA regions （rbcL, matK, and trnH-psbA）, were used to differentiate species within Ligustrum. BLAST, character-based method, tree-based methods and TAXONDNA analysis were used to investigate the molecular identification capabilities of the chosen markers for discriminating 92 samples representing 20 species of this genus. The results showed that the ITS sequences have the most variable information, followed by trnH-psbA, matK, and rbcL. All sequences of the four regions correctly identified the species at the genus level using BLAST alignment. At the species level, the discriminating power of rbcL, marK, trnH-psbA, and ITS based on neighbor-joining （NJ） trees was 36.8%, 38.9%, 77.8%, and 80%, respectively. Using character-based and maximum parsimony （MP） tree methods together, the discriminating ability of trnH-psbA increased to 88.9%. All species could be differentiated using ITS when combining the NJ tree method with character-based or MP tree methods. Overall, the results indicate that DNA barcoding is an effective molecular identification method for Ligustrum species. We propose the nuclear ribosomal ITS as a plant barcode for plant identification and trnH-psbA as a candidate barcode sequence.

关 键 词：DNA barcoding internal transcribed spacer （ITS） Ligustrum MATK TRNH-PSBA rbcL. 

分 类 号：Q949.288.4[生物学—植物学] O434[机械工程—光学工程]