Development of Quantitative Real-Time PCR Assays to Quantify Erysiphe pisi and Erysiphe trifolii and Its Implementation for Monitoring Their Relative Prevalence in Pea Crops in Spain and Tunisia

E. pisi was thought to be the only causal agent of powdery mildew in peas, with three genes, er1, er2 and Er3, conferring resistance this pathogen. Recently, trifolii has also been found cause disease peas different countries, but its relevance pea worldwide is unknown. The objective study develop a method identify quantify use it analyze relative prevalence fields Spain Tunisia. We wanted discern effect Er3 genes on amount pisi/E. trifolii. Using polymorphic sites present between ITS sequences, we developed qPCR capable identifying quantifying these pathogens. Our results revealed, for first time, occurrence Tunisia that presence have clear ratio both countries.