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Poster: Diseases of Plants: Disease Detection & Diagnosis


Rapid and sensitive detection of tomato chlorotic dwarf viroid in crude plant extracts using isothermal RT-recombinase polymerase amplification
R. HAMMOND (1), S. Zhang (2) (1) USDA ARS, U.S.A.; (2) Agdia, Inc., U.S.A.

Tomato chlorotic dwarf viroid (TCDVd) is a serious threat to tomato production worldwide. Infection leads to reduced plant vigor, small and deformed fruit, and yield loss. TCDVd is easily transmitted mechanically from plant to plant once introduced and through seed; seed treatments do not control transmission of disease. The most effective control is the use of certified viroid-free planting materials. We developed a molecular diagnostic assay utilizing reverse transcription-recombinase polymerase amplification (RT-RPA) at an isothermal constant temperature of 39 °C and target-specific primers and probe for the rapid, sensitive, and specific detection of TCDVd in crude extracts of infected leaf and seed tissues. The performance of the AmplifyRP® Acceler8TM RT-RPA diagnostic assay, utilizing a lateral flow strip contained within an amplicon detection chamber, was evaluated and the results were compared with a standard RT-PCR assay. The AmplifyRP® Acceler8TM assay was specific for TCDVd and its sensitivity was comparable to conventional RT-PCR. The assay does not require extensive sample purification, specialized equipment, or technical expertise. It is easy to perform and can be used under both laboratory and field conditions.