Although DNA barcoding has been widely   used to identify plant species composition in temperate and tropical   ecosystems, relatively few studies have used DNA barcodes to document both   herbaceous and woody components of forest plot. A total of 201 species (72   woody species and 129 herbaceous species) representing 135 genera distributed   across 64 families of seed plants were collected in a 25 ha CForBio subalpine   forest dynamics plot. In total, 491 specimens were screened for three DNA regions   of the chloroplast genome (rbcL, matK, and trnH-psbA) as well as the internal   transcribed spacers (ITS) of nuclear ribosomal DNA. We quantified species   resolution for each barcode separately or in combination using a ML   tree-based method. Amplification and sequencing success were highest for   rbcL, followed by trnH-psbA, which performed better than ITS and matK. The   rbcL + ITS barcode had slightly higher species resolution rates (88.60%)   compared with rbcL + matK (86.60%) and rbcL + trnH-psbA (86.01%). The   addition of trnH-psbA or ITS to the rbcL + matK barcode only marginally   increased species resolution rates, although in combination the four barcodes   had the highest discriminatory power (90.21%). The situations where DNA barcodes   did not discriminate among species were typically associated with higher   numbers of co-occurring con-generic species. In addition, herbaceous species were   much better resolved than woody species. Our study represents one of the   first applications of DNA barcodes in a subalpine forest dynamics plot and   contributes to our understanding of patterns of genetic divergence among   woody and herbaceous plant species.  

虽然DNA条形码已被广泛应用于温带和热带生态系统中植物物种的组成鉴定，但很少有研究使用DNA条形码来记录林地的草本植物和木本植物成分。在中国森林生物多样性监测网络中，我们选择了一个25公顷的亚高山森林动态图，在该图对应的区域内，共采集64科，135属，201种种子植物（72种木本植物，129种草本植物）。筛选了491个叶绿体基因组的3个DNA区域（rbcl、matK和trnH-psbA）和细胞核核糖体DNA的转录间隔区（ITS）。我们使用基于ML树的方法分别或组合量化每个条形码的物种分辨率。rbcL的扩增和测序成功率最高，其次是trnH-psbA，其表现优于ITS和matK。与rbcL + matK（86.60%）和rbcL + trnH-psbA（86.01%）相比，rbcL + ITS的物种分辨率略高（88.60%）。在rbcL + matK组合的基础上添加trnH-psbA或ITS只会略微提高物种的分辨率，这四种条码的结合具有最高的分辨力（90.21%）。DNA条形码在物种间没有区别的情况通常与较高的共生同属物种的数量有关。此外，草本植物比木本植物更容易分辨。我们的研究是DNA条形码在亚高山森林动态图中的首次应用，有助于我们理解木本和草本植物物种之间的遗传分化模式。