基于GenBank分析28S(D2/D3)、18S和ITS序列作为根结线虫条形码标记的适用性  

Evaluation of 28S(D2/D3) ,18S and ITS loci as DNA barcode markers for the root-knot nematodes based on data mining from GenBank

作　　者：林宇[1,2] 王金成[2] 迟元凯[1] 鞠玉亮[1] 王暄[1] 李红梅[1] 

机构地区：[1]南京农业大学植物保护学院/农作物生物灾害综合治理教育部重点实验室,江苏南京210095 [2]天津出入境检验检疫局动植物与食品检测中心,天津300461

出　　处：《南京农业大学学报》2013年第5期71-76,共6页Journal of Nanjing Agricultural University

基　　金：国家质检总局科技计划项目(2011IK176);国家公益性行业(农业)科研专项(201103018);国家自然科学基金项目(30900939)

摘　　要：基于GenBank中根结线虫属的核酸序列,筛选了28S(D2/D3)、18S和ITS 3个不同的序列片段,利用遗传距离法和分子系统学方法评价其各自作为根结线虫条形码标记的可行性。结果显示:28S(D2/D3)、18S及ITS的核酸序列种内平均遗传距离分别为0.004 3、0.002 7和0.024,种间平均遗传距离分别为0.074、0.036和0.156,由于属内近缘种的影响,各分子标记的种内、种间遗传距离均有一定的重叠;基于K2P模型构建的3种分子标记NJ系统发育树显示,南方根结线虫、爪哇根结线虫、花生根结线虫均混合聚类,难以区分;经统计,28S(D2/D3)、18S及ITS对根结线虫属内不同种的识别率分别为74%、60%和46%。研究表明:28S(D2/D3)具有一定的遗传距离间隔以及相对较高的物种识别率,可以作为根结线虫属候选条形码标记。In order to evaluate the feasibility of 28S （D2/D3）, 18S and ITS loci as candidate DNA barcode markers for root-knot nematodes （ Meloidogyne spp. ）, the nucleotide sequences retrieved from GenBank were analysed using pair-wise distance and phylogenetic methods. The results revealed that the average intraspecific divergences of 28S （D2/D3） , 18S and ITS are 0. 004 3, 0. 002 7 and 0. 024, respectively; for interspecific, are 0. 074,0. 036 and 0. 156, respectively. The genetic distances between intraspecific and interspecific of 3 loci showed some overlapping due to the existence of close sibling species of Meloidogyne. The neighbour-joining trees of sequences from 3 loci constructed by K2P model demonstrated that M. incognita, M. javanica and M. arenaria were mixed grouping and difficult to be separated each other into one branch. The loci of 28S（ D2/D3 ）, 18S and ITS resolved 74% ,60% and 46% of the Meloidogyne species we tested, respectively. In overall, the 28S （D2/D3）locus was evaluated as a candidate barcode marker for Meloidogyne spp. due to its larger barcoding gap and higher species resolution.

关 键 词：根结线虫属 DNA条形码 遗传距离 系统发育 物种鉴定 

分 类 号：S432.45[农业科学—植物病理学] Q19[农业科学—农业昆虫与害虫防治]