Real-time PCR detection of Elsinoë spp. on Citrus

Elsinoë species are the causal agents of scab and spot diseases on many economically important plant species. Diagnosis based on symptomology is often problematic and traditional methods are not appropriate as Elsinoë spp. are notoriously difficult to isolate and slow growing. Three Elsinoë species which infect Citrus are regulated as quarantine organisms within the European Union. Reliable and fast detection of Elsinoë species on citrus fruit is essential for effective phytosanitary control. In this study, a multiplex real-time PCR was designed for rapid and sensitive detection of Elsinoë species and validation was focused on citrus fruit. The test was specific to the Elsinoë genus when tested against a range of non-target pathogens and had the ability to detect all three regulated Elsinoë species on Citrus. The test also proved highly sensitive with a limit of detection of 12 fg of DNA per reaction. This new test can be used as a tool in the diagnostic process for the rapid and sensitive detection of Elsinoë pathogens on symptomatic plant material.