云南常见药用石斛DNA条形码筛选

选择云南省内常见的12种药用石斛,采用分子生物学鉴定技术筛选其适用的DNA条形码序列。以12种药用石斛共36个样品为材料,提取样品总DNA,对核基因片段ITS和ITS2、叶绿体基因片段psbA-trnH和matK序列进行扩增、测序;利用生物信息学软件进行序列分析和系统发育分析。结果表明,4条序列扩增和测序成功率均为100%;4条序列没有明显的Barcoding Gap,但ITS序列与ITS2序列的种内和种间重叠部分较少,有偏向两端的趋势;系统发育树显示,ITS和psbA-trnH序列能成功区分12种云南常见的药用石斛,ITS2序列未能区分长距石斛(Dendrobium longicornu)和矮石斛(D.bellatulum),mat K序列仅区分6种石斛。建议以ITS和psbA-trnH序列作为云南药用石斛鉴定序列,为药用石斛的种源鉴定提供理论依据。

Screening of DNA Barcoding for Medicinal Dendrobium in Yunnan

Twelve common medicinal Dendrobium species in Yunnan province were selected, and molecular biology identification techniques were used to screen DNA barcoding sequences suitable for Yunnan medicinal Dendrobium. A total of 36 samples of 12 kinds of medicinal Dendrobium (Dendrobium devonianum, D. chrysotoxum, D. falconeri, etc.) were used as materials to extract the total DNA of the samples, and the nuclear gene fragments ITS and ITS2, the chloroplast gene fragment psbA-trnH and matK sequences were amplified and sequenced, part of the Dendrobium sequence was downloaded in GenBank; Sequence analysis and phylogenetic analysis were used by bioinformatics software. The results showed that the success rates of amplification and sequencing of the 4 sequences were 100% and all of them had no obvious Barcoding Gap, but there was a small amount of overlap between the ITS sequence and the ITS2 sequence within and between species, which tended to be biased towards both ends. The phylogenetic tree showed that the ITS and psbA-trnH sequences could successfully distinguish the 12 medicinal Dendrobiums in this study, the ITS2 sequence failed to distinguish D. longicornu and D. bellatulum. The matK sequence only distinguished 6 species of Dendrobium. It is suggested that ITS and psbA-trnH sequences should be regarded as the identification sequence of Yunnan medicinal Dendrobium to provide theoretical basis for the provenance identification of medicinal Dendrobium.