铁皮石斛的SCAR标记研究

Study on Sequence Characterized Amplified Region(SCAR) Markers in Dendrobium candidum

目的:建立快速准确的铁皮石斛DNA分子鉴定方法。方法:采用RAPD方法对11种石斛进行多态性分析,获得铁皮石斛特异的RAPD分子标记片段;经克隆、测序,重新设计一对特异性引物转化成稳定的SCAR标记。结果:获得了1条稳定扩增的铁皮石斛特异的片段DS-302,序列测定结果表明,全长302 bp,通过BLAST搜索、同源性比较,结果表明该段序列与已知数据库中的所有序列无显著同源性。根据该序列设计1对特异引物,对11种石斛进行扩增,可在铁皮石斛中扩增获得约300 bp的片段,而石斛属其他种未出现该条带。结论:DS-302成功转化为SCAR分子标记,可对铁皮石斛进行快速有效的鉴定。

Objective：To establish an effective way for rapid identification of Dendrobium candidum based on DNA molecular marker.Methods：The genetic diversity among 11 wild species of Dendrobium was studied by using the random amplification polymorphism DNA.The special segment with random primer in Dendrobium candidum was recovered,cloned and sequenced.According to its sequence,a pair of specific primers was synthesized and tested for the specific detection of Dendrobium candidum.Results：The results of PCR showed that only a 302 bp electrophoresis band of Dendrobium candidum named DS-302 was found.According to the result of sequence analysis in the Genbank databases,no distinct comparability was found.And a specific primer was designed and used to identify Dendrobium candidum from other Dendrobium species effectively.There was a same band like DS-302 in Dendrobium candi-dum,but not be discovered in other species of Dendrobium.Conclusions：The RAPD marker DS-302 was successfully converted into SCAR marker.It was an effective way to identify Dendrobium candidum more rapidly.