Differentiation of Two Pathogens of Powdery Mildew Disease in Flowering Dogwood (Cornus florida) by PCR‐mediated Method Based on ITS Sequences

Abstract

Two fungi, Phyllactinia guttata and Erysiphe pulchra were identified as the pathogens of powdery mildew of flowering dogwood (Cornus florida). The objective of this research was to identify and distinguish the two fungi by developing species-specific primers. The internal transcribed spacer (ITS) universal primers and a series of species-specific primers designed from the ITS regions were used to evaluate and validate the two fungi causing powdery mildew in dogwood. Four primer pairs showed specificity to P. guttata and three to E. pulchra. These species-specific primer pairs can be used as molecular markers to provide diagnostic tools for detection and differentiation of the two powdery mildew pathogens in flowering dogwood.