线粒体COI基因作为根结线虫条形码的适用性分析  

Suitability analysis of mitochondrial COI gene used as DNA barcode for root-knot nematodes

作　　者：林宇[1,2] 王金成[1] 张瑞峰[1] 陈先锋[3] 顾建锋[3] 李红梅[2] 

机构地区：[1]天津出入境检验检疫局,天津300456 [2]南京农业大学 [3]宁波出入境检验检疫局

出　　处：《植物检疫》2016年第2期34-39,共6页Plant Quarantine

基　　金：国家质检总局课题(2011IK176);国家科技支撑计划项目(2012BAK11B03);天津局科技项目(2013TK072)

摘　　要：为评估线粒体COI基因作为根结线虫(Meloidogyne spp.)DNA条形码的适用性,对收集的25个根结线虫群体的线粒体COI基因进行扩增、测序,检测其扩增和测序成功率。将测序获得的COI基因序列与Q-bank中下载的根结线虫COI基因序列共同进行比对分析,利用MEGA 6.0计算种内、种间遗传距离进行"Barcoding Gap"检验以及构建NJ系统进化树作聚类分析,检验COI基因对根结线虫的物种识别能力。结果表明:线粒体COI基因扩增和测序成功率极高,扩增成功率达96%,测序成功率为100%。种间平均遗传距离为0.126,远远超过种内平均遗传距离0.002的10倍,种内遗传距离与种间遗传距离存在明显的"Barcoding Gap"间隔区。系统发育分析显示,COI基因可有效分辨出本研究15种根结线虫中的10种,物种识别率约为67%。线粒体COI基因具有极高的扩增和测序成功率、较高的物种识别能力,且扩增片段长度适宜,符合物种鉴定DNA条形码基因的标准,可作为根结线虫候选条形码基因。To evaluate the suitability of mitochondrial COI gene as DNA barcode for root-knot nematodes（Meloidogyne spp.）,the COI gene of 25 populations of root knot nematodes were amplified and sequenced to test the success rate of PCR amplification and sequencing;Using MEGA 6.0 software,the COI gene sequences from this study and download from Q-bank were combined together to calculate the intraspecific and interspecific genetic distances for ＂Barcoding Gap＂ assay and also NJ phylogenetic tree was constructed to test the species recognition rate of mitochondrial COI gene for root-knot nematodes.The results revealed that mitochondrial COI gene has very high success rate of 96% for PCR amplification and 100% for sequencing. The average interspecific genetic distance（0.126） is far more than 10 times of the average intraspecific genetic distance（0.002）,meaning divergent ＂Barcoding Gap＂ between intraspecific and interspecific genetic distances. Phylogenetic analysis revealed that COI gene could recognized 10 species out of the 15 species of root knot nematodes used in this study,and species recognition rate is about 67%. Because of appropriate amplicon length,high success rate of amplification and sequencing and good ability of species recognition,which are consistent with the criteria of DNA barcoding gene for species identification,the mitochondrial COI gene could be used as a candidate DNA barcode for Meloidogyne spp..

关 键 词：根结线虫 DNA条形码 线粒体细胞色素C氧化酶I基因 物种鉴定 

分 类 号：S432.45[农业科学—植物病理学]