Abstract: 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 COI) 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.

Key words: Bemisia tabaci, cryptic species, mtDNA COI, SNP, allele-selective PCR, fluorescent quantitation