Key Laboratory of Biodiversity and Biogeography, and Germplasm Bank of Wild Species in Southwest China, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, Yunnan 650204, China.
Mol Ecol Resour. 2012 Mar;12(2):267-75. doi: 10.1111/j.1755-0998.2011.03095.x. Epub 2011 Dec 4.
DNA barcoding is a technique to identify species by using standardized DNA sequences. In this study, a total of 105 samples, representing 30 Parnassia species, were collected to test the effectiveness of four proposed DNA barcodes (rbcL, matK, trnH-psbA and ITS) for species identification. Our results demonstrated that all four candidate DNA markers have a maximum level of primer universality and sequencing success. As a single DNA marker, the ITS region provided the highest species resolution with 86.7%, followed by trnH-psbA with 73.3%. The combination of the core barcode regions, matK+rbcL, gave the lowest species identification success (63.3%) among any combination of multiple markers and was found unsuitable as DNA barcode for Parnassia. The combination of ITS+trnH-psbA achieved the highest species discrimination with 90.0% resolution (27 of 30 sampled species), equal to the four-marker combination and higher than any two or three marker combination including rbcL or matK. Therefore, matK and rbcL should not be used as DNA barcodes for the species identification of Parnassia. Based on the overall performance, the combination of ITS+trnH-psbA is proposed as the most suitable DNA barcode for identifying Parnassia species. DNA barcoding is a useful technique and provides a reliable and effective mean for the discrimination of Parnassia species, and in combination with morphology-based taxonomy, will be a robust approach for tackling taxonomically complex groups. In the light of our findings, we found among the three species not identified a possible cryptic speciation event in Parnassia.
DNA 条形码技术是一种通过使用标准化的 DNA 序列来鉴定物种的技术。在这项研究中，共采集了 105 个样本，代表 30 种蒲包花属植物，以测试四个建议的 DNA 条形码（rbcL、matK、trnH-psbA 和 ITS）用于物种鉴定的有效性。我们的结果表明，所有四个候选 DNA 标记都具有最高水平的引物通用性和测序成功率。作为单个 DNA 标记，ITS 区提供了最高的物种分辨率，为 86.7%，其次是 trnH-psbA，为 73.3%。多个标记组合中，核心条形码区域 matK+rbcL 的组合的物种鉴定成功率最低（63.3%），被发现不适合作为蒲包花的 DNA 条形码。ITS+trnH-psbA 的组合具有最高的物种鉴别能力，分辨率为 90.0%（30 个采样物种中的 27 个），与四标记组合相等，高于任何包括 rbcL 或 matK 的两个或三个标记组合。因此，matK 和 rbcL 不应用于蒲包花属植物的物种鉴定。基于整体表现，建议将 ITS+trnH-psbA 的组合作为鉴定蒲包花属物种的最适合 DNA 条形码。DNA 条形码技术是一种有用的技术，为蒲包花属植物的鉴别提供了可靠和有效的手段，与基于形态的分类学相结合，将成为解决分类复杂的群体的有力方法。根据我们的发现，我们在三个未识别的物种中发现了蒲包花属中可能存在的隐种现象。
