Detection of Golovinomyces orontii using species-specific primers and high-resolution melting analysis

Abstract

This study presents the development of species-specific PCR primers for detection of Golovinomyces orontii, the causal agent of powdery mildew disease on different cucurbit hosts. The species-specific primers CgF2 and CgR2 were designed based on partial ITS and 5.8S rDNA sequences using an isolates collection of powdery mildew and downy mildew pathogens from different sources. After optimization of the PCR conditions, a 233 bp fragment was amplified only from DNA of G. orontii. Limit of detection was determined to be 0.01 ng of pure conidial genomic DNA. Further association of PCR and high-resolution melting (HRM) analysis showed that the designed primer set can be used for differentiation of G. orontii from different powdery mildew fungi in infected cucurbits tissue collected in the field.