Development of a Novel Diagnostic Tool for Cercospora Species Based on BOX-PCR System.

The genus Cercospora contains many devastating plant pathogens linked to leaf spot diseases afflicting various plants. Identification of Cercospora species based on morphology or host plant association has proven unreliable due to simple morphology and wide host range in many cases; hence, multi-gene DNA sequence data are essential for accurate species identification. Considering the complexity and cost involved in application of multi-locus DNA phylogenetic approaches for species delineation in Cercospora; rapid and cost-effective methods are urgently needed for species recognition. In this study, we applied rep-PCR (repetitive-sequence based polymerase chain reaction) fingerprinting methods referred to as BOX-PCR to differentiate species of Cercospora. Cluster analysis of the banding patterns of 52 Cercospora strains indicated the ability of BOX-PCR technique using BOXA1R primer to generate species-specific DNA fingerprints from all the tested strains. Since this technique was able to discriminate between all the 20 examined Cercospora species during this study, which corresponded well to the species identified based on multi-gene DNA sequence data, our findings revealed the efficiency of BOX-PCR system as a suitable complementary method for molecular identification of the genus Cercospora at species level.