目的 分析ITS2、rbcL序列在牛奶菜属植物及其近缘植物间的鉴别能力，并对牛奶菜属植物及其近缘植物的系统进化进行初步分析。方法 采用直接测序法测定所分析样品的ITS2、rbcL序列，获得的序列采用软件CodonCode Aligner人工校正，Contig软件拼接，用MEGA 4.0软件分析比对并进行遗传距离等分析，用NJ法对比对的序列构建系统分支树。结果 ITS2、rbcL序列对牛奶菜属植物及其他所分析样品有较好的鉴别能力，且鉴别能力ITS2优于rbcL；南山藤属、匙羹藤属植物与牛奶菜属植物间的亲缘关系非常相近。结论 条形码ITS2、rbcL序列能很好地区分牛奶菜属植物，且鉴别能力ITS2优于rbcL；建议将南山藤属、匙羹藤属等小属植物归入牛奶菜属内。

Objective To identify and preliminarily analyze the plants of Marsdenia R. Br. and its related species by ITS2 and rbcL sequences. Methods The ITS2 and rbcL regions were amplified and sequenced directly. The sequence was manually calibrated using CodonCode Aligner, and splited and jointed by Contig software. The genetic distance analysis was carried out by MEGA 4.0 and the phylogenetic tree was constructed using the Neighbor-joining method. Results The samples analyzed were well identified by ITS2 and rbcL sequences, and the authentication ability of ITS2 was superior to rbcL. The genetic relationship among the plants of Marsdenia R. Br., Dregea E. Mey., and Gymnema R. Br. was very close. Conclusion ITS2 and rbcL sequences could distinguish Marsdenia R. Br. species very well, and the authentication ability of ITS2 is superior to rbcL. The preliminary studies suggest that the Dregea E. Mey. and Gymnema R. Br. should be classified into genus Marsdenia R. Br.

中国医学科学院药用植物研究所中央级公益性科研院所基本科研业务专项（YZYN-09-04）