根据形态特征难以准确地辨别金合欢属植物,DNA条形码技术提供了一种准确地鉴定物种的方法。本文利用条形码技术对中国金合欢属物种的序列(psbA-trnH、matK、rbcL和ITS)及其不同组合进行比较,通过计算种内和种间变异进行barcoding gap分析,运用Wilcoxon秩和检验比较不同序列的变异性,构建系统树。结果表明:4个片段均存在barcodinggap,ITS序列种间变异率较psbA-trnH、rbcL和matK序列有明显优势,单片段ITS正确鉴定率最高,ITS+rbcL片段联合条码的正确鉴定率最高,因此我们认为ITS片段或条形码组合ITS+rbcL是金合欢属的快速鉴别最理想的条码。
It is difficult to identify Chinese species of Acacia accurately based on morphological assessment unless an intact specimen is at hand. In contrast, DNA barcoding through the analysis of short DNA sequences from a small sample of tissue can provide an accurate method for identifying species. In this study, we used four DNA fragments (rbcL, marK, psbA-trnH, and ITS) to develop a potential barcoding method for Chinese Acacia. Our analysis in- volved calculating inter- and intra-specific genetic distances, conducting Wilcoxon signed rank tests to analyze the sequence variation, and constructing phylogenetic trees from distance data. The results showed that barcoding gaps exist between Acacia species for each of the four sequences, with ITS showing highest inter-specific divergence. Both the use of ITS on its own and in combination with rbcL sequence variation gave the highest level of species identifica- tion. We therefore propose the use of ITS sequence variation on its own or combined with rbcL as a DNA barcode for identifying Acacia species in China.