植物物种的快速鉴定与iFlora: DNA条形码在马先蒿属中的应用

DNA条形码技术就是利用一段较短的标准DNA序列对物种进行快速鉴定。与基于植物外部形态特征的传统分类鉴定方法相比， DNA条形码具有高效、准确，且易于实现自动化和标准化的特点。马先蒿属（Pedicularis L.）植物具对生（轮生）叶的种类70%以上分布在中国，近缘种间形态上非常相似，鉴定较为困难。研究选取马先蒿属具对生（轮生）叶类群43种164份样品，利用叶绿体基因（rbcL、matK、trnH psbA）和核基因（ITS）条形码片段，采用建树法和距离法检验4个条形码对这些物种的鉴定效果。结果表明，ITS片段用于建树法和距离法的鉴别率分别为81.40%和89.57%，其鉴别率高于3个叶绿体基因片段和任一基因片段的组合条码。另外，利用ITS成功解决了一些疑难种的分类问题。DNA条形码在马先蒿属研究中的实用性为新一代植物志（iFlora）实现物种的快速和准确鉴定提供了有力支持，并能为分类学、生态学、进化生物学、居群遗传学和保护遗传学等分支学科的研究提供重要信息。

Rapid Identification of Plant Species and iFlora: Application of DNA Barcoding in a Large Temperate Genus Pedicularis (Orobanchaceae)

DNA barcoding involves species identification using a short and standardized DNA region. This method has many advantages over traditional morphology based identification, including greater effectivity, sensitivity, reliability, and standardization. In this study, we used 43 whorled /opposite leaved species from the genus Pedicularis as a model system to test the utility of DNA barcoding for rapid identification of species in the taxa where traditional identification methods are time consuming and inaccurate. Four candidate DNA barcoding loci (three chloroplast: rbcL, matK, trnH psbA, and one nuclear: ITS) were evaluated by tree and distance based methods using a total of 164 accessions. Our results showed that species identification rates using the nuclear ITS locus (81.40% and 89.57% for tree and distance based methods, respectively) surpassed those of the three chloroplast barcodes and all combinations of barcodes. In addition, the nuclear ITS locus was able to help identify some species that had previously been difficult to differentiate using only morphological traits. The demonstrated ability of DNA barcoding to efficiently discriminate among these Pedicularis species highlights the practicality and importance of its utility for the next generation intelligent Flora (iFlora) in fulfilling the rapid and accurate identification of species. This new identification method will provide key information for traditional taxonomy and for investigations of ecology, evolutionary biology, population genetics, and conservation genetics, etc.