海南花梨木DNA条形码序列测定-毕业论文.doc

毕业论文(设计) 题目: 海南花梨木 D NA 条形码序列测定学号: 姓名: 年级: 学院: 系别: 专业: 指导教师: 完成日期: 海南花梨木 DNA 条形码序列测定 I 摘要 DNA 条形码作为生命体所固有的遗传物质,客观存在于细胞内的物质,不受人为因素干扰,能准确的反映出物种最基本的信息。为了验证国际生命条形码联盟推荐的 MatK , trnH-psbA , ITS2 三个候选条形码,在珍贵木材降香黄檀( Dalbergia odorifera T. Chen) 又名花梨木 DNA 条形码测定中的有效性。从基地采摘的降香黄檀叶片中提取 DNA , 用特异性引物进行 PCR 扩增,得到三条候选条形码的目的片段,扩增成功的 DNA 片段可用于进一步测序分析。以 PCR 扩增成功率和测序成功率初步评价候选 DNA 条形码片段,评选出最优的条形码片段,为今后利用 DN A 条形码鉴定木材和构建木材分子条形码数据库提供理论依据。实验结果:只有 ITS2 的条形码片段测序成功,得到对应的序列。通过 NCBI 查询黄檀属其他物种的 ITS2 序列,得到:降香黄檀的 ITS2 分子序列与黄檀属植物均不同,其中与越南黄檀差异最小,其次是多裂黄檀。多重比对后构建该序列的进化树结果说明降香黄檀与越南黄檀、多裂黄檀有着较近的亲缘关系,但又不属于同一植物类群,且三者有着稳定的遗传差异性。建议把 ITS2 序列作为鉴定降香黄檀的候选条形码序列。关键词: 降香黄檀; DNA 条形码; ITS2 ;分子鉴定降香黄檀 DNA 条形码序列测定 II II Abstract DNA barcode as the ic materialin life inherent that objectively existed in the cell, without artificial interference. It could accurately reflect the most essential information for species. In order to verify t hree candidate barcodes of the MatK, trnH – psbA and ITS2 mended by CBOL and the effectiveness in Dalbergia odorifera ’s DNA barcode. Extracted DNA of its leaves from the base,using specific primers for PCR amplication. The purpose of the three candidates from bar code fragments were obtained and the targeted segment was amplified essfully to be used for sequencing analysis. PCR amplification and sequencing ess rate could be used for the preliminary evaluation the bar code fragments of candidate DNA ,Selected the best bar code fragment,which provided theoretical basis for using DNA identification of wood and wood construction molecule. The results were as follows : only ITS2 coded fragment was essfully sequenced. and the corresponding sequence was gained. By searched ITS2 of other species which belong to Dalbergia from NCBI. We got the consion conclusion that: ITS2 of Dalbergia odorifera were different,with Dalbergia tonkinensis minimum, followed by Dalbergia rimosa parison after building the sequence of the evolutionary tree result showed that Dalbergia odorifera Dalbergia tonkinensis and