Real-time polymerase chain reaction for identification of a highly pathogenic group of Fusarium oxysporum f.sp. chrysanthemi on argyranthemum frutescens L.

A real-time Polymerase Chain Reaction (PCR) system based on Taqman® chemistry was developed in order to identify a new group of Fusarium oxysporum f.sp. chrysanthemi highly pathogenic on Paris daisy (VCG 0052). Sensitivity of PCR and real-time PCR was compared on genomic DNA from mycelium. The ability to identify symptomless infections on daisy was also evaluated using selective substrate, PCR and real-time PCR. Real-time PCR could identify infected plants on the fifth day after artificial inoculation, although plants remained symptomless until the 13th day after inoculation. The real-time PCR could detect as little as 300 fg of genomic DNA. The advantages of real-time PCR as a diagnostic system for this new epidemic disease are discussed.