A multiple PCR-LDR assay for identification of two invasive cryptic species of whiteflies Bemisia tabaci

Abstract

The MEAM1 and MED species of the cryptic species complex Bemisia tabaci are important invasive pests that cause tremendous crop losses worldwide. A rapid and highly reliable molecular technique is necessary to identify these species because they are morphologically indistinguishable. Therefore, a multiple polymerase chain reaction coupled with a ligase detection reaction (PCR-LDR) that was based on polymorphisms in the mitochondrial cytochrome oxidase I (mtCOI) gene of B. tabaci was developed to distinguish the two cryptic species. An assessment of the method indicated that PCR-LDR provided high specificity and sensitivity in discriminating MEAM1 (SHB) and MED (SHQ) whiteflies. In field tests, PCR-LDR genotyping was performed in one 96-well plate to identify 93 individuals collected from 8 districts in the suburbs of Shanghai. Complete concordance was observed between PCR-LDR and sequencing methods. The method was used to confirm that MEAM1 and MED were found in two districts, but only the MED was found in the other six districts. PCR-LDR, which is a transplantable platform, provides an alternative method for species identification of B. tabaci at low cost.