中国红树类海桑属植物DNA条形码研究＊

目的 对中国的6种红树类海桑属植物进行DNA条形码研究,为该属植物鉴定、资源保护、合理开发等提供参考依据。方法 以核基因ITS2片段及叶绿体基因片段psbA-trnH作为DNA条形码,对分布在中国的海桑属植物进行基因组DNA提取、PCR扩增和双向测序。所得序列经CodonCode Aligner拼接获得叶绿体psbA-trnH基因间区序列和核ITS2序列,用软件MEGA6.0进行相关数据分析,构建NJ（邻接）树。结果 我国6种红树类海桑属植物的ITS2序列间存在明显差异,psbA-trnH序列间也存在一定的碱基差异,表明6种海桑属植物具有其各自独特的DNA条形码,可以相互区别,同时基于ITS2序列及psbA-trnH序列构建的邻接（NJ）树可以看出6种海桑属植物具有或近或远的亲缘关系。结论 核ITS2和叶绿体psbA-trnH序列作为DNA条形码可以有效地区分和鉴别我国6种红树类海桑属植物,为后续药用资源开发等相关研究提供了参考。

Study on DNA Barcoding of Sonneratia of Chinese Mangrove Plants

Objective To carry out DNA barcode research on six species of Sonneratia of Chinese mangrove plants, and provide references for their identification, rational development, and resources protection.Methods The second internal transcribed spacer (ITS2) of ribosomal DNA and chloroplast gene fragments psbA-trnH were used as DNA barcodes, and the DNA extraction, PCR amplification, DNA bi-directional sequencing of six species of Sonneratia in China were carried out. Sequence assembly and consensus sequence generation were performed by using CodonCode Aligner. Phylogenetic study was performed using MEGA 6.0 software in accordance with the Kimura 2-Parameter (K2P) model, and the phylogenetic tree was constructed using the neighbor-joining (NJ) methods.Results The six species of Sonneratia in our country existed obvious difference in the ITS2 sequence, and had some difference in the psbA-trnH sequence, which showed that they had own unique DNA barcode and could be identified by the sequences difference of the ITS2 and psbA-trnH sequences. And meanwhile, the phylogenetic tree based on ITS2 sequences and psbA-trnH sequences could also showed the genetic relationship among the six species of Sonneratia.Conclusion ITS2 and psbA-trnH barcode sequences can serve as valuable markers for identifying and distinguishing species of Sonneratia, and then provide references for the relative research.