植物DNA条形码研究进展

Current advances of DNA barcoding study in plants

DNA条形码(DNA barcoding)已成为近5年来国际上生物多样性研究的热点,即通过使用短的标准DNA片段,对物种进行快速、准确的识别和鉴定。该技术在动物研究中已得到广泛的应用,所采用的标准片段是线粒体COI基因中约650bp长的一段。然而在植物中DNA条形码的研究进展相对缓慢,目前尚处于对所提议的各片段比较和评价阶段,还未获得一致的标准片段。由于植物中线粒体基因组进化速率较慢,因此条形码片段主要在叶绿体基因组上进行选择,被提议的编码基因片段主要有rpoB,rpoC1,matK,rbcL,UPA,非编码区片段有trnH-psbA,atpF-atpH,psbK-psbI,此外还有核基因ITS。已有的研究表明以上任何一个单片段都不足以区分所有植物物种,因而不同的研究组相继提出了不同的片段组合方案,目前被广泛讨论的组合主要有5种。本文综述了DNA条形码序列的优点、标准、工作流程、分析方法和存在的争议,重点论述了植物条形码研究中被提议的各序列片段和组合的研究现状。

DNA barcoding has become one of hotspots of biodiversity research in the last five years. It is a method of rapid and accurate species identification and recognition using a short, standardized DNA region. DNA barcoding is now well established for animals, using a portion of the mitochondrial cytochrome c oxidase subunit 1 （COl or cox1） as the standard universal barcode. However, in plants, progress has been hampered by slow substitution rates in mitochondrial DNA. A number of different chloroplast regions have been proposed. There has been considerable debate, but little consensus regarding region choice for DNA barcoding land plants. Direct comparative assessment of different barcoding regions is now a priority to enable a standard barcoding solution to be agreed in plants. The proposed chloroplast barcoding regions mainly include five coding （rpoB, rpoCl, matK, rbcL, UPA） and three non-coding （trnH-psbA, atpF-atpH, psbK-psbl） regions. In addition, nrITS is also suggested as a potential plant barcode. Limited by the universality and resolvability of single barcoding region, five combinations of these regions are proposed. In this review, the advance of these barcoding regions, both their universality of primers and resolving power are reviewed. The advantages, standards, workflow and existent dispute of DNA barcoding are summarized.