Wang Hui, Shi Ling-Ling, Zhou Jue, Zhu Guo-Ping
Anhui Provincial Key Laboratory of the Conservation and Exploitation of Biological Resources, Institute of Molecular Biology and Biotechnology, Anhui Normal University, Wuhu 241000, China.
Wannan Medical College, Wuhu 241000, China.
Zhongguo Zhong Yao Za Zhi. 2018 Oct;43(20):4055-4061. doi: 10.19540/j.cnki.cjcmm.2018.0107.
This research preliminarily discusses the relations of Dendrobium system growth through chloroplast gene rbcL, matK and the nuclear genome ITS2. The DNA barcoding universal sequence for authentication of the Dendrobium medical plants was slected and the possibility concerning utilizing the DNA barcoding to distinguish the D. huoshanenseand its adulterants was analyzed. Using the universal primer pair of ITS2, rbcL and matK, series of extended sequencing in the Dendrobium were conducted. Meanwhile, considering the different index about amplification and sequencing success rate of each sequence, the intraspecific and interspecific aberrance, the employment of BioEdit and MEGA 5.0 software were applied to establish the systematic tree of the NJ molecular and evaluate the diversified authentication capability of various sequences. The consequence demonstrates that the sequence of ITS2 is not only the largest one both in the intraspecific and interspecific aberrance of the Dendrobium but also has obvious barcoding gap. Considering the few overlap between the intraspecific and interspecific aberrance and the highest percentage regarding the formation of unilateral branch in diverse Dendrobium which have different ITS2 sequences, it can differentiate the species of Dendrobium. Furthermore, due to the inferior success rate of the rbcL and thematK and the lower reliability of NJ systematic tree, the percentage of the unilateral species which are generated by the systematic tree of rbcL and matK sequences is deficient. Therefore, the sequence of ITS2 can serves as DNA barcoding to distinguish the D. huoshanense, the D. moniliform and the D. officinale.
本研究通过叶绿体基因rbcL、matK以及核基因组ITS2初步探讨了石斛属系统发育关系。筛选出用于鉴定石斛属药用植物的DNA条形码通用序列，并分析利用DNA条形码区分霍山石斛及其混伪品的可能性。使用ITS2、rbcL和matK通用引物对，对石斛属进行了系列扩增测序。同时，考虑到各序列扩增和测序成功率、种内种间差异等不同指标，应用BioEdit和MEGA 5.0软件构建NJ分子系统树并评估各序列的鉴别能力。结果表明，ITS2序列不仅在石斛属种内种间差异中最大，且具有明显的条形码间隙。考虑到种内种间差异重叠少，且不同ITS2序列的石斛属中形成单系分支的比例最高，故其可区分石斛属物种。此外，由于rbcL和matK的成功率较低，且NJ系统树可靠性较差，由rbcL和matK序列系统树产生的单系物种比例不足。因此，ITS2序列可作为DNA条形码用于区分霍山石斛、细茎石斛和铁皮石斛。
