Quantitative Detection of Citrus tristeza virus (CTV) in Citrus and Aphids by Real-time Reverse Transcription-PCR (TaqMan®)

A quantitative real-time reverse transcription (RT)-polymerase chain reaction (PCR) assay for rapid detection of Citrus tristeza virus (CTV) was developed and tested successfully on a wide array of biologically diverse CTV isolates collected from around the world. The qPCR method uses fluorescent molecules to measure the PCR directly while amplification is taking place. This molecular assay is faster and more sensitive than serology or conventional RT-PCR. Concentrations of less than 2 fentograms could be detected from infected citrus tissue while the amount of virus in aphids was estimated to range from 12,000 to 13,000,000 copies of CTV RNAs. In summary, the real time RT-PCR assay developed is a valuable new tool for CTV detection and quantification.