利用TaqMan等位基因技术鉴定烟粉虱MEAM1和MED隐种

Discrimination of cryptic species MEAM1 and MED of Bemisia tabaci (Hemiptera: Aleyrodidae) by using TaqMan allele-selective PCR

MEAM1和MED是烟粉虱Bemisia tabaci两种重要的外来入侵隐种,在我国部分地区常混合发生,对我国农业生产造成了不同程度的危害和损失。尤其是MED隐种危害寄主范围更广,对多种杀虫剂具有较高抗性,防治上更为困难。因此,如何快速鉴定烟粉虱MEAM1和MED隐种,对于烟粉虱防治策略的选择具有十分重要的意义。本研究选择线粒体细胞色素氧化酶I(mitochondrial cytochrome oxidaseI,mtDNACOI)基因保守区域内的单核苷酸多态性(SNP)为靶标,应用等位基因聚合酶链式反应技术,借助TaqMan-MGB荧光染色标记探针,建立了一种鉴定烟粉虱MEAM1和MED隐种的等位基因选择性PCR方法,并对北京11个区县的14个烟粉虱种群进行了隐种鉴定。结果表明,北京地区14个烟粉虱种群样本与已知烟粉虱MED隐种种群在荧光值分布上聚为一簇,为MED隐种。该鉴定方法具备SNP基因分型的优点,可快速、可靠、高通量地鉴定烟粉虱MEAM1和MED,为烟粉虱隐种鉴定及遗传分化研究提供了新的可选途径。

The whitefly Bemisia tabaci is considered taxonomically as a species complex which contains some destructive pests worldwide. Two of the most prevalent cryptic species are B. tabaci Middle East- Asia Minor 1 （MEAM1） and Mediterranean （MED）. They are invasive cryptic species and often occur in some areas in China. The MED particularly has strong resistance to some insecticides and is more difficult to be controlled. In this study TaqMan allele-selective PCR was used for high-throughput allelic discrimination of MEAM1 and MED. A single nucleotide polymorphism （SNP） in a conservative region of the mitochondrial cytochrome oxidase I （mtDNA CO1） gene was selected as the amplification target. The TaqMan-MGB fluorescent dye-labeled was used in real-time quantitative PCR. Fourteen populations of B. tabaci collected from Beijing were identified with the method. The results showed that all samples of B. tabaci clustered with the known MED species as shown by the higher fluorescence of FAM dye in scatter plot analysis of fluorescence data, suggesting that all Beijing populations examined are MED. The results prove that the method has the advantage of SNP genotyping, with which MEAM1 and MED can be identified rapidly, reliably and high-throughput, and this provides a new alternative way for identification of cryptic species and important information for management strategy selection.