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United States Department of Agriculture

Agricultural Research Service

Research Project: SUBTROPICAL INSECT PESTS OF VEGETABLES AND ORNAMENTAL PLANTS

Location: Subtropical Insects and Horticulture Research

Title: Identification of the MEAM1 cryptic species of Bemisia tabaci (Hemiptera: Aleyrodidae) by loop-mediated isothermal amplification

Authors
item Dickey, Aaron
item Osborne, Lance -
item Shatters, Robert
item McKenzie, Cindy

Submitted to: Florida Entomologist
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: June 28, 2013
Publication Date: September 1, 2013
Citation: Dickey, A.M., Osborne, L.S., Shatters, Jr., R.G., McKenzie, C.L. 2013. Identification of the MEAM1 cryptic species of Bemisia tabaci (Hemiptera: Aleyrodidae) by loop-mediated isothermal amplification. Florida Entomologist. 96(3):756-764.

Interpretive Summary: The Bemisia tabaci cryptic species complex of whiteflies contains two invasive groups, MEAM1 and MED. We used a constant-temperature DNA amplification method to detect these groups. Target specific amplification primer sets developed in house and those previously published were compared for specificity by measuring the time-to-amplification of non-target and target DNA. Primer sets designed for MEAM1 were more specific than those designed for MED across published studies and in house designed primers. The optimal primer set for MEAM1, in conjunction with an indicator producing a color change in positive samples, provided visual confirmation of target whitefly DNA presence in 45 minutes. This chemical test was highly specific and did not amplify DNA from eight additional groups within the Bemisia tabaci cryptic species complex or from ten other whitefly species found in Florida. The chemical test shows promise as the foundation of a field-based tool that could identify the most commonly encountered Florida whitefly species quickly.

Technical Abstract: There are two major invasive cryptic species within the Bemisia tabaci 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 group by measuring time-to-amplification of non-target and target DNA templates using real-time polymerase chain reaction. All these primer sets were designed using the mitochondrial cytochrome oxidase I gene. Our findings indicate that primer sets designed for MEAM1 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 minutes. This assay was highly specific and did not amplify DNA from eight additional sweetpotato whitefly cryptic species or from ten non-Bemisia whitefly species found in Florida. The assay amplified non-target DNA from one 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 identify the most commonly encountered Florida whitefly species quickly.

Last Modified: 8/22/2014
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