结合叶绿体和核DNA序列变异可提高云杉属物种的分子鉴别率  

The Combination of Chloroplast and Nuclear DNA Fragments Could Improve the Discrimination Power for Barcoding Spruce (Picea) Species

作　　者：邹嘉宾[1] 王茜[1] 李丽丽[1] 刘建全[1] 

机构地区：[1]兰州大学生命科学学院草地农业系统国家重点实验室,甘肃兰州730000

出　　处：《植物分类与资源学报》2013年第3期375-385,共11页Plant Diversity

基　　金：科技部科技基础性工作专项重点项目(2007FY110100);国家自然科学基金项目(30930072)

摘　　要：松科(Pinaceae)云杉属(Picea)植物是北半球广泛分布的重要森林树种,由于频繁的种间杂交渐渗及近期的辐射分化导致种间形态趋同,传统的形态学方法很难准确鉴定该属物种。近期兴起和发展的DNA条形码技术为云杉属物种的划分和鉴定提供了可参考的方法。在云杉属青藏高原种质资源收集过程完成后,选取5个叶绿体DNA片段(matK,rbcL,trnH-psbA,trnL-trnF和trnS-trnG)以及3个核DNA片段(4CL,Sb29和GI),利用PWG-distance和Tree-Building两种方法对青藏高原以及中国其他地区分布的19个云杉属物种83个个体进行了物种鉴别分辨率的评价。研究结果显示单个的叶绿体DNA片段(10.5%～26.3%)和核DNA片段(15.8%～26.3%)对云杉属物种鉴别的分辨率较低,组合的叶绿体DNA片段的分辨能力(15.8%～42.1%)虽然高于单个DNA片段,但分辨率最高的trnH-psbA+trnS-trnG和trnS-trnG+trnL-trnF两个组合也只能达到42.1%;组合的核DNA片段(26.3%～36.8%)一样对云杉属物种鉴别存在困难。但是叶绿体DNA片段和核DNA片段的组合可以明显提高对云杉属物种鉴定的分辨率,尤其是trnS-trnG+trnL-trnF+4Cl的组合片段,其分辨率可达到57.9%。因此在将来利用DNA条形码鉴别物种时,在常规DNA条形码片段不起作用的情况下,可采用这种叶绿体DNA片段和核DNA片段组合的方法来鉴定和区分植物物种。Spruces （Picea）, a genus of Pinaceae, are important components of the forests in the Northern Hemi- sphere. It is relatively difficult to distinguish species by using traditional morphological method due to frequent inter- specific hybridization and introgression, and radiative diversification. However, the emerging and developing of the DNA barcoding methods provide an alternative approach. In this study, we tested the discrimination powers between five chloroplast DNA regions （marK, rbcL, trnH-psbA, trnL-trnF and trnS-trnG）, three nuclear DNA regions （4CL, Sb29 and GI） and the combination of these fragments in spruces. We sampled 83 trees, which represent 19 spruce species mainly from Qinghai-Tibetan Plateau and also from other regions of China. We used two methods, PWG-distance and Tree-Building, to conduct barcoding analsyes. A single chloroplast DNA fragment （10.5%- 26.3% ） or a single nuclear DNA fragment （ 15.8% -26.3% ） always shows low level of species discrimination rate. Although the combination of the chloroplast DNA fragments had higher discrimination rate than the single one,the highest rate of discrimination was only 42. 1% for both combinations of trnH-psbA＋trnS-trnG and trnS-trnG＋ trnL-trnF. And the combination of the nuclear DNA fragments also showed lower rates of discrimination （26.3% - 36.8% ）. It thus appears that it is difficult to discriminate spruce species using only chloroplast DNA fragments or nuclear DNA regions. However, the combination of chloroplast and nuclear DNA regions had higher resolution for i- dentifying spruce species, especially for trnS-trnG＋trnL-trnF＋4C1, whose discrimination rate can reach up to 57.9%. Therefore, in the future, this combination of fragments from chloroplast and nuclear can be widely adopted for the discrimination of plant species when the normal DNA barcodes fail to work.

关 键 词：云杉属 DNA条形码 核DNA片段 物种鉴别 

分 类 号：Q949[生物学—植物学] Q75