天麻ITS序列分析及变异类型鉴定

Identification of Different Types in Gastrodia elata Based on the Analysis of ITS Sequence

目的:选取天麻3种变型有代表性的样品进行ITS序列(DNA基因的内转录间隔区序列)测序分析,从分子水平对天麻不同变异类型亲缘关系作出鉴定。方法:采用改进CTAB法提取天麻DNA,利用合成的特异引物对其DNA中ITS区进行扩增、克隆,对目的片段测序分析。结果:黄天麻和绿天麻首先构成两个姊妹群,它们的遗传距离约为25,乌天麻与它们的遗传距离约为50,而且它们之间的遗传距离都达到了100%的置信度。其中ITS1的209个碱基中仅仅有15个位点的差异,相同碱基数目达到92.8%,这15个变异位点可作为天麻变型间的特异性鉴定。结论:表明ITS区序列分析可作为鉴定天麻不同变异类型的一种新方法。

Objective：In order to further identify the differences in three representative samples of Gastrodia elata,their ITS sequences of rDNA genes were amplified,sequenced and analyzed.It is indicated that there are different relationship between them from the level of molecular variation.Method：Genomic DNA from Gastrodia elata extracted by modified CTAB method were regarded as templates for PCR amplification,cloning and sequencing by synthetic specific primer the nrDNA ITS sequences.Result：G.elata Bl.f.flavida S.Chow and G.elata Bl.f.viridis Mak constitute the first two sister groups,their genetic distance were about 25,G.elata Bl.f.glauca S.Chow and their genetic distance were about 50 and the genetic distance between them has reached the 100% confidence.In the amplified ITS1 sequence with 209bp,there are 15 varied base sites which could be used as specific characters to identify three types.In terms of the natural population scale,G.elata Bl.f.glauca is much richer than other types in Genetic diversity,it might be the original type of G.elata species in phylogeny and evolution.Conclusion： From the above,sequence analysis of ITS provides a new approach to identify the Gastrodia elata resources.