中药秦艽基原植物的DNA分子鉴定

目的]分析秦艽基原植物间不同DNA序列的差异,为秦艽药材DNA条形码的筛选和基原鉴定提供分子证据。方法]采用PCR扩增纯化后直接测序的方法,测定大叶秦艽G.macrophylla pall.、麻花秦艽G.straminea Maxim.、粗茎秦艽G.crassicaulis Duth-ieex Burk.、小秦艽G.dahurica Fisch、黄管秦艽G.officinalis H.Smith5种植物的核糖体DNAITS、叶绿体DNA psbA-trnH核苷酸序列,并作序列同源性分析。结果]cpDNA psbA-trnH序列长度变异范围为316-318bp,有7种不同的单倍型,单倍型间有7个变异位点,序列的GC含量为21.2%。最大简约树的聚类结果与单倍型反映的结果一致。nrDNA ITS序列长度变异范围为624～625bp。有5种不同的单倍型、单倍型间有12个变异位点,序列的GC含量为59.3%。最大简约树的聚类结果表明,小秦艽与麻花艽聚为一支,大叶秦艽与黄管秦艽聚为一支,粗茎秦艽位于聚类图的最基部。结论]nrDNAITS序列较适合作秦艽基原植物的DNA分子鉴定。

DNA Molecular Identification of Botanical Origin in Chinese Herb Qingjiao

Objective] The research aimed to distinguish Chinese herb Qingjiao from its botanical origin plants by comparing different DNA sequences,so as to provide a molecular basis for origin identification and quality evaluation.Method] The cpDNA psbA-trnH and nrDNA ITS sequences of five Chinese herb Qingjiao plants,including Gentiana macrophylla pall.,Gentiana straminea Maxim.,Gentiana crassicaulis Duthie ex Burk.,Gentiana dahurica Fisch and Gentiana officinalis H.Smith,were amplified with PCR,and then sequenced by direct PCR sequencing method for homologous analysis.Results] The length of cpDNA psbA-trnH of five plants was 316-318 bp;there were seven different haplotypes and seven variable sites;the GC content of the sequence was 21.2%;the phylogenetic clustering showed the same result as haplotype analysis.The length of nrDNA ITS sequence of five plants was 624-625 bp,there were five different haplotypes and 13 variable sites;the GC content of the sequence was 59.3%.The result of phylogenetic clustering suggested that G.dahurica and G.straminea,G.macrophylla and G.officinalis clustered together as sister clades,respectively.Conclusion] The nucleotide differences of nrDNA ITS regions could be used for distinguishing botanical origin in Chinese herb Qingjiao.