[Objective] The study aimed to analyze the ITS sequences of nrDNA from Rhodiola alisa and investigate the difference of evolution rate between nrDNA and trnS-trnG and rpl20-rps12 sequences of cpDNA(chloroplast DNA).[Method]Total DNA was extracted from silica-dried leaves of R.alsia by using modified CTAB method.With the extracted DNA sample as template,nrDNA ITS region was amplified,then purified and sequenced.In addition,the yielded ITS sequences were also compared with the known trnS-trnG and rpl20-rps12 sequences of cpDNA from R.alsia.[Result]The ITS sequence of nrDNA from R.alsia was 701 bp in length,of which 13 variable sites were found with a percentage of 1.85%.Of the 13 variable sites,8 were caused by point mutations,5 were the results of insertions or deletions.The(A+T)content and(G+C)content were 46.9% and 53.1%,respectively.The nucleotide diversity(π)was 0.004 27.[Conclusion]The ITS region of nrDNA from R.alsia was more conservative and evolved more slowly than the trnS-trnG and rpl20-rps12 sequences of its cpDNA.
[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.
