茶组植物种间关系的cpDNA、rDNA ITS和mtDNA序列分析

Analysis on cpDNA,rDNA ITS and mtDNA Sequences among Interspecific Relationships of Camellia sinensis ( L.) O. Kuntze

【目的】DNA序列分析在物种系统进化、分类和鉴定等方面展示出了强大的生命力。【方法】本研究对来源于cpDNA、rDNA ITS和mtDNA序列的15对引物在茶组植物的5种2变种共16份资源中进行了种间关系研究。【结果】在15对引物中,来自cpDNA的6对引物有5对完成了扩增与测序,来自rDNA ITS的3对引物均未得到单一目的片度,来自mtDNA序列的6对引物中,共有4对完成了扩增与测序。对在种间存在位点差异的8对引物序列比对:序列长度最长的为390F-1326R(859 bp),最短的为orf25(446 bp);品种间变异位点最多的为rbcla-rev(24个),最少的为nad4L/orf25(2个)。位点变异率最高的为rbcla-rev(4.76%),最低为nad4L/orf25(0.37%),cpDNA的碱基变异率平均值(2.91%)要远高于mtDNA(0.55%);8对引物在茶变种内发生变异的位点共有9个,占总位点数的0.19%;不同变种间发生变异的位点有90个,占总位点数的1.85%;将8对引物测序得到的序列拼接,按照MP法构建了分子系统树,可以将参试的16份茶树资源分为3大类。【结论】本研究为DNA序列分析在茶组植物中的应用提供了参考。

【Objective】DNA sequence analysis had provided a more convenient method for plant phylogenetic analysis,identification,classification and so on. 【Method】15 pairs of primer from the gene sequences of cpDNA,rDNA and mtDNA were designed,which were used to analyze the interspecific relationships of 16 tea germplasm resources which were collected from 5 species and 2 variants of tea plant. 【Result】5 cpDNA primer pairs and 4 mtDNA primers were amplified and sequenced,3 rDNA ITS primers fail to be amplified in all accessions.There were 8 pairs of primer with mutation sites among all accessions were used to do DNA sequence analysis,and the result indicated that the longest sequence was 390 F-1326 R( 859 bp),and the shortest one was orf25( 446 bp). The rbcla-rev had the most informative positions( 24),and the nad4 L/orf25 was just the opposition( 2). Site variable ratio varied from 0. 37 %( nad4 L/orf25) to 4. 76 %( rbcla-rev),and the average in cpDNA( 2. 91 %) was much higher than that in mtDNA( 0. 55 %); There were 9 variable sites within Camellia. sinensis var.sinensis,accounting for 0. 19 % of total loci,and 90 variable sites between different species,accounting for 1. 85 % of total loci; 8 sequences were spliced to construct molecular phylogenetic tree according to the MP method,in which 16 accessions were divided into 3 groups. 【Conclusion】This study would provide useful references for the application of DNA sequence analysis in the tea plant.