A molecular diagnosis method using real-time PCR for quantification and detection of Fusarium oxysporum f. sp. cubense race 4

The Fusarium genus causes devastating plant diseases worldwide, in which Fusarium oxysporum is the most serious crop pathogen. Disease monitoring is the basis of integrated pest management of any disease. The lack of rapid, accurate, and reliable device to detect and identify plant pathogens is one of the main limitations in integrated disease management. This study describes an efficient and quantifiable diagnosis method for the specific detection of F. oxysporum f. sp. cubense (Foc) race 4 in field-infected banana. With the optimized PCR parameters using the SCAR (sequence characterized amplified region) primers FocSc-1/FocSc-2 and a real-time PCR strategy, the developed method showed high reproducibility and was very sensitive to detect extremely low quantities of Foc genomic DNA (gDNA). We also found that Foc gDNA in severely symptomatic banana pseudostems and leaves were 6946-fold and 26.69-fold more than in those of mild-symptomatic banana, respectively.