目的评价几个热点DNA条形码候选序列对葫芦科植物的鉴别能力。方法使用ITS2、rbcL、matK和psbA-trnH序列的通用引物对葫芦科植物进行PCR扩增和测序,通过比较各序列的扩增和测序成功率、种内和种间的变异、barcodinggap,并采取相似性探索BLAST 1和最近距离Nearest Distance方法评价不同序列的鉴别能力。结果 ITS2序列对葫芦科33个属、90个物种、182个样本进行分析,其鉴定成功率较高,在属水平为100.0%,在物种水平为88.5%;psbA-trnH序列对201个样本进行分析,其鉴定成功率在属水平为93.0%,在物种水平为73.1%,但其可以补充部分ITS2不能分析的物种区域。结论 ITS2和psbA-trnH是适合葫芦科植物鉴别的一个较好的DNA条形码序列组合。

To evaluate the candidate sequence of several hotspot DNA barcodes for identification ability on the species in Cucurbitaceae family. Methods Using universal primers, three chloroplast sequences, psbA-trnH, rbcL, matK, and a nuclear ribosomal DNA ITS2 were amplified and sequenced. PCR amplification and sequencing efficiency, intra- and inter-specific variation,barcoding gap, and identification efficiency (with BLAST 1 and Nearest Distance methods) were used to evaluate these loci. Results The rate of successful identification using ITS2 sequence was 88.5% at the species level and 100% at the genera level for 182 plant samples belonging to 90 species from 33 distinct genera in Cucurbitaceae. The rate of successful identification using psbA-trnH sequence was 73.1 % at the species level and 93.0% at the genera level，but it could complement some species region which could not be successfully discriminated by ITS2 sequence. Conclusion It proposes that the combination of ITS2 and psbA-trnH senquence is promising for the identification of the species in Cucurbitaceae.

国际科技合作项目(2007DFA30990);卫生行业科研专项资助项目(200802043)