APPLICATION OF A REVERSE TRANSCRIPTION LOOP-MEDIATED ISOTHERMAL AMPLIFICATION (RT-LAMP) AND REVERSE-TRANSCRIPTION POLYMERASE CHAIN REACTION (RT-PCR) FOR THE DETECTION OF CUCURBIT YELLOW STUNTING DISORDER VIRUS (CYSDV) IN EGYPT.

Cucumbers and squash affected by Cucurbit yellow stunting disorder virus (CYSDV) show severe yellowing symptoms in the field and greenhouse-grown plants in Egypt and are heavily infested by Bemisia tabaci Genn.. Symptoms start as an interveinal chlorosis on the older leaves and intensify as leaves age. In order to detect CYSDV reverse transcription-polymerase chain reaction (RT-PCR) techniques were developed that target either the coat protein gene in RNA2 or p22 in RNA1. Electrophoretic analysis of the RT-PCR amplification revealed the primers amplified products of 756 bp for the coat protein ORF and 560 bp for p22. Reverse transcription loop-mediated isothermal amplification (RT-LAMP) was also developed and proved to be a rapid method with high specificity and efficiency under isothermal condition using a set of six specifically designed primers that recognize six distinct sequences on the target gene p22.RT-LAMP was reliable for diagnosis of CYSDV-infected leaf samples and insect vectors from the field in 60 min. RT-LAMP has the potential to replace PCR due to its simplicity, rapidity, specificity, sensitivity and cost-effectiveness without the need for specialized equipment.