Identification of the Meam1 Cryptic Species of Bemisia tabaci (Hemiptera: Aleyrodidae) by Loop-Mediated Isothermal Amplification

Abstract

There are 2 major invasive cryptic species within the Bemisia tabaci Gennadius (Hemiptera: Aleyrodidae) cryptic species complex in Florida, called MEAM1 or biotype B, and MED or biotype Q. We used loop-mediated isothermal amplification of DNA to detect these groups. Primer sets developed in-house and those previously published were compared for specificity to the target species by measuring time-to-amplification of non-target and target DNA templates using real-time PCR. All these primer sets were designed using the mitochondrial cytochrome oxidase I gene. Our findings indicate that primer sets designed for MEAMl were more specific than those designed for MED across published studies and in-house designed primers. The optimal primer set for MEAM1 detection, in conjunction with the magnesium ion color indicator hydroxynaphthol blue, provided visual confirmation of target whitefly DNA amplification in 45 min. This assay was highly specific and did not amplify DNA from 8 additional sweetpotato whitefly cryptic species nor from 10 non-Bemisia whitefly species found in Florida. The assay amplified non-target DNA from 1 sweetpotato whitefly cryptic species not present in Florida and shows potential to amplify MED DNA rarely. While additional genes should be used to design more specific primers, particularly for MED, this MEAM1 assay shows promise as the foundation of a field-based tool that could quickly identify the most commonly encountered Florida whitefly species.

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