蓼属头状蓼组rDNA-ITS的序列扩增及分析

Sequence Analysis of Internal Transcribed Spacer of Polygonum Sect.Cephalophilon and Its Systematic Utility

以贵州境内蓼属头状蓼组6种（含1变种）植物为材料,对其rDNA的内转录间隔区（ITS）序列进行PCR扩增,得到6种植物的ITS序列,分别为：赤胫散2个居群（Polygonum runcinatumvar.sinense,GenBank登录号FJ606887、FJ648802）,平卧蓼（P.strindbergii,GenBank登录号FJ648803）,尼泊尔蓼（P.nepalense,GenBank登录号FJ648804）,羽叶蓼（P.runcinatum,GenBank登录号FJ648805）,火炭母（P.chinense,GenBank登录号FJ648806）和头花蓼（P.capitatum,GenBank登录号FJ648807）.其中赤胫散与平卧蓼的ITS序列为首次报道.序列分析结果表明,蓼属头状蓼组6种植物ITS序列总长度为661-666 bp,ITS1区序列长度为243-246 bp,5.8 S rDNA区序列长度165 bp,ITS2区序列长度253-258 bp,6种植物的差异主要集中在ITS1和ITS2区.聚类分析显示,6种头状蓼组植物具有共同起源,结果支持赤胫散从羽叶蓼变种上升为独立物种.

With 6 species（including 1 variety）of Polygonum Sect.Cephalophilon which distributed in Guizhou Province as experimental material,the sequences of rDNA internal transcribed spacer（ITS） were amplified by means of PCR.All 7 sequences of 6 species of Polygonum Sect.Cephalophilon were deposited in GenBank,there are 5 species and 1 variations populations based on morphological character in the district,Polygonum runcinatum var.sinense（Genbank accession number FJ606887,FJ648802）,P.strindbergii（Genbank accession number FJ648803）,P.nepalense（Genbank accession number FJ648804）,P.runcinatum（Genbank accession number FJ648805）,P.chinense（Genbank accession number FJ648806） and P.capitatum（Genbank accession number FJ648807）.In which,the ITS of P.runcinatum var.sinense and P.strindbergii are the first time to be accessed in GenBank.The results showed that the length of the ITS is 661～666 bp,ITS1 243～246 bp,5.8S rDNA 165 bp and ITS2 253～258 bp.The mainly differences are in ITS1 and ITS2 domain.The phylogenetic tree indicated that all Polygonum Sect.Cephalophilon species collected from Guizhou originated from a same ancestor and P.runcinatum var.sinense should be a distinct species,instead of a variation of P.runcinatum.