Development of a Polymerase Spiral Reaction-Based Isothermal Assay for Rapid Identification of Thrips palmi

Abstract

Thrips cause considerable economic losses to a wide range of food, feed, and forest crops. They also transmit several plant viruses. Being cryptic, it is often difficult to distinguish thrips species in crops and large consignments by conventional methods. Melon thrips (Thrips palmi Karny, Thysanoptera: Thripidae) is an invasive insect pest of vegetables, legumes, and ornamentals besides being vector to several viruses. It poses a threat to domestic and international plant biosecurity and can invade and establish in new areas. Here, we report a polymerase spiral reaction (PSR)-based isothermal assay for rapid, sensitive, specific, low-cost, and on-site detection of T. palmi. To the best of our knowledge, this is the first application of PSR in the identification of any insect species. A primer pair designed based on 3′-polymorphism of mtCOIII region can specifically identify T. palmi without any cross-reactivity with predominant thrips species. The assay uses crude lysate of a single thrips saving time and reagents involved in nucleic acid extraction. The presence of T. palmi is visualized by the appearance of bright fluorescence under ultraviolet light or a change in reaction color thus avoiding gel electrophoresis steps. The entire process can be completed in 70 min on-site using only an ordinary water bath. The assay is sensitive to detecting as little as 50 attograms of T. palmi template. The assay was validated with known thrips specimens and found to be efficient in diagnosing T. palmi under natural conditions. The described method will be useful for non-expert personnel to detect an early infestation, accidental introduction to a new area, restrict the spread of diseases and formulate appropriate management strategies.

Rapid detection of human cytomegalovirus by multienzyme isothermal rapid amplification and lateral flow dipsticks

“…Multiple enzymes are required for RPA reactions, and the conditions are more stringent ( James and Macdonald, 2015 ). PSR is carried out at 65°C for approximately 70 minutes ( Jangra et al., 2022 ). Some PCR-based techniques, including quantitative PCR and fast single tube nested real-time PCR, have been used for detecting breast milk ( Romero-Gómez et al., 2015 ; Martins-Celini et al., 2016 ).…”

Interspecific and intraspecific variation in susceptibility of two co‐occurring pest thrips, Frankliniella occidentalis and Thrips palmi, to nine insecticides

“…However, with ongoing directional selection, all populations would eventually be expected to show resistance. Given differences among thrips species in chemical responses and the challenges of identifying thrips morphologically, molecular identification of thrips species may help when implementing insecticide resistance management of pest thrips 53,54 …”

“…Given differences among thrips species in chemical responses and the challenges of identifying thrips morphologically, molecular identification of thrips species may help when implementing insecticide resistance management of pest thrips. 53,54 Species displacement is a common phenomenon among thrips. 7 The performance of thrips can be influenced by biotic and abiotic factors and thus mediate species competition.…”

Deciphering the Role of Virus Receptors in Plant–Virus–Vector Interactions

“…Thrips-transmitted viruses cause severe losses to various crop plants worldwide [33,34]. Young thrips larvae acquire the virus while feeding on infected hosts and are transmitted by adults throughout their lifespan.…”