利用DNA条形码技术识别植物物种

Identification of plant species based on DNA barcode technology

DNA条形码技术能够快速、准确地识别物种,对于开展基础性的分类学研究和应用性的生物多样性研究极为重要.本文对鼎湖山20hm2大样地183个植物物种进行DNA条形码测序.结果表明:单个条形码片段时,psbA-trnH的综合成功率最高(75%),其次是matK(70%)和rbcL(56%);片段组合时,matK+rbcL+psbA-trnH三片段组合的物种水平识别率在87%以上,随后是matK+psbA-trnH(85%)、rbcL+psbA-trnH(83%)和matK+rbcL(81%).综合了亚热带波多黎各的LFDP样地(143个种)和热带巴拿马的BCI样地(296个种)以及圭亚那的Nouragues样地(254个种)3个森林类型的研究结果,评价DNA条形码各片段在4个森林样地的通用性.在热带和亚热带地区的森林样地中,各片段测序成功率分别为rbcL(93%,95.1%)、psbA-trnH(91.5%,94.6%)和matK(68.5%,79.7%).在植物类群水平上,核心条形码片段matK+rbcL组合的物种准确识别率不高,只在局部群落中表现较为理想;而三位点DNA条形码片段组合在热带和亚热带森林样地中综合成功率可达84%和90%.

It is crucial for the studies of taxonomy and biodiversity by using DNA barcode technolo- gy to fast and accurately make species identification in the forests across tropics and temperate zones. In this study, the 183 plant species in a 20 hm2 subtropical forest plot in Dinghushan （DHS） National Nature Reserve of South China were sampled and sequenced, and the marK, rbcL, and psbA-trnH were employed to generate muhi-locus barcodes. For the plot, the psbA-trnH pos- sessed the highest integral success rate, i. e. , the product of sequencing recovery and correct spe- cies identification （75%）, followed by marK （70%）, and rbcL （56%）. A combination of three- locus barcode （marK, rbcL and psbA-trrtH） could identify greater than 87% of the total species, followed by two-locus barcode （85% for matK＋psbA-trnH, 83% for rbcL＋psbA-trnH, and 81% for matK＋rbcL）. A comparison was made with the previously published results from one subtropical forest plot （LFDP in Puerto Rico, 143 species） and two tropical forest plots （BCI in Panama, 296 species; and NRS in French Guiana, 254 species） to evaluate the universality and species identifi- cation correctness of the proposed DNA barcodes for these four forest plots. For the plots in tropics and subtropics, the sequencing success rate of rbcL, psbA-trnH and matK were 93% and 95.1%, 91.5% and 94.6%, and 68.5% and 79.7%, respectively. The combination of matK＋rbcL showed a high identification capacity in geographically restricted regions in taxonomic groups, whereas the three-locus barcode had a high rate of correct species identification both in tropics （84%） and in subtropics （90%）.