Molecular tools in monitoring the outset of tomato leaf curl virus (ToLCV) Transmission in the Philippines

Abstract

The study validated the use of Loop-Mediated Isothermal Amplification (LAMP) and polymerase chain reaction (PCR) in tracking the possible cause of transmission of the tomato leaf curl virus (ToLCV). Detection of ToLCV was performed by assessing the detection rate from the parallel tests of these molecular methods against the greenhouse-controlled conventional method. Assessment of symptomatic and asymptomatic plants was conducted before sampling and processing for the assays. Plant viruses are commonly transmitted by vectors, most significantly by the Silverleaf whiteflies or Bemisia tabaci. Here, PCR and LAMP detected the virus in seedlings 0-dpi (0-day post-inoculation) even before the symptoms appeared while yellowing and minor curling of leaflet ends were observed in tomato plants at 12 dpi. Results revealed that the transmission of ToLCV occurs not only via the insect vector but this virus can also be transmitted through contaminated seeds and can be expected in soil particles. The results suggest the benefits of using these molecular diagnostic methods for ToLCV in detecting the early stage of infection when symptoms are not yet fully expressed thus, saving the assay time, resources and most importantly, the crops.