基于DNA条形码ITS对西藏不同地理居群红景天的鉴定研究

Identification of Hongjingtian from Different Geographical Populations in Xizang Based on DNA Bar Code ITS

目的:对大花红景天和长鞭红景天进行2种DNA条形码的碱基序列分析,并构建系统进化树,为大花红景天的真伪鉴定提供参考。方法:提取3份样品基因组DNA,对内转录间隔区(internal transcribed spacer,ITS)片段进行PCR扩增,双向测序,获得其序列信息;运用MEGA7.0对所有样品的ITS序列及GenBank共21条进行比对、计算种内种间遗传距离,构建Neighbor-Joining(NJ)系统进化树。结果:编号为A1~A14的大花红景天聚为一支,编号为K1~K7的长鞭红景天聚为一支;同时发现ITS序列信息变化与地域和环境明显相关。结论:将ITS序列作为DNA条形码能准确、快速地鉴别大花红景天,可为其种质资源鉴定及物种鉴别提供依据。

Objective:To provide the reference for the identification of Dahua Hongjingtian[Rhodiola crenulata(Hook.f.et Thoms.)H.Ohba]by analyzing the base sequences of DNA bar codes of Dahua Hongjingtian and Changbian Hongjingtian[Rhodiola fastigiata(HK.f.et Thoms.)S.H.Fu]and constructing the phylogenetic tree.Methods:The fragments of internal transcribed spacer(ITS)were amplified by PCR and sequenced in two directions to obtain their sequence information after extracting the genomic DNA of three samples;MEGA 7.0 was used to compare the ITS sequences of all the samples and GenBank,a total of 21 entries,calculate the intraspecific interspecific genetic distances,and construct Neighbor-Joining(NJ)phylogenetic trees.Results:Numbers A1-A14 Dahua Hongjingtian clustered into one unit,and numbers K1-K7 Changbian Hongjingtian clustered into one unit;meanwhile,the variation of the ITS sequence information was obviously correlated with the geographic areas and environments.Conclusion:ITS sequence as DNA bar code can accurately and quickly identify Dahua Hongjingtian,which could provide an important basis for its germplasm resource identification and species identification.