第十一章 花梨木DNA条形码测定.doc

毕 业 论 文（设计） 题 目：海南花梨木DNA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 PAGE \* MERGEFORMAT PAGE \* MERGEFORMAT 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DNA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 PAGE \* MERGEFORMAT II PAGE \* MERGEFORMAT II Abstract DNA barcode as the genetic 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 three candidate barcodes of the MatK, trnH – psbA and ITS2 recommended 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 successfully to be used for sequencing analysis. PCR amplification and sequencing success 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 successfully sequenced. and the corresponding sequence was gained. By searched ITS2 of other species w