基于清风藤属植物DNA条形码的叶绿体序列筛选

基于叶绿体基因matK、psbK-psbI、psbA-trnH序列分析9种清风藤属植物DNA条形码可行性。结果表明,清风藤属3条叶绿体基因中,matK序列最长(805 bp);psbA-trnH序列的GC含量最低(29.7%),变异位点数(46)与简约信息位点数(32)最多。种间变异顺序为:psbA-trnH>matK>psbK-psbI;种内变异顺序为:psbA-trnH>psbK-psbI>matK。遗传距离分析、barcoding gap分析与Wilcoxon秩和检验分析结果显示,在9种清风藤属植物中,只有psbA-trnH序列种内最大变异小于种间最小变异,matK序列种间差异较大。从系统进化树分析结果看,3条序列均可以区分部分物种,matK序列鉴定效率较高。因此,3条序列均不适合单独作为该属植物的DNA条形码。在后续的研究中,建议以matK作为DNA条形码辅助序列与其它候选序列进行联合分析,以提高清风藤属DNA条形码鉴定效率。

Chloroplast Coding Sequence Selection Based on the DNA Barcoding of the Genus Sabiaceae

The feasibility of DNA barcoding of nine species of Sabiaceae was analyzed based on the sequence of chloroplast gene matK, psbK-psbI and psbA-trnH. The results showed that the matK sequence was the longest(805 bp) among the three chloroplast genes of Sabiaceae. The GC content of psbA-trnH sequence was the lowest(29.7%), and the number of mutation sites(46) and reduced information sites(32) was the highest. The sequence of interspecific variation was as follows:psbA-trnH>matK>psbK-psbI;The sequence of intraspecific variation was: psbA-trnH>psbK-psbI>matK. The results of Genetic Distance analysis, Barcoding Gap analysis and Wilcoxon Rank and T-test analysis showed that, among the nine species of Sabiaceae, only in psbA-trnH sequence, the intra-specific maximum variation of psbA-trnH sequence was smaller than the inter-specific minimum variation, and the inter-species difference of matK sequence was significant. According to the results of phylogenetic tree analysis, all the three sequences could distinguish part of species, and the efficiency of matK sequence identification was much higher. Hence, the three sequences are not suitable to be used as the DNA barcodes for this genus alone. In the following studies, it is suggested to use matK as an assistant sequence of DNA barcoding to conduct joint analysis with other candidate sequences, so as to improve the efficiency of DNA barcoding identification of Sabiaceae plants.