Erysiphe cornicola, a Powdery Mildew Occurring on Cornus controversa in Korea

In Korea, Cornus controversa and C. florida are known as hosts of Erysiphe pulchra from section Microspharea of the genus Erysiphe. However, recent molecular-phylogenetic analyses on the internal transcribed spacer regions and large subunit gene of the rDNA revealed that the Erysiphe powdery mildew on C. controversa in Japan is in fact E. cornicola. To assess the taxonomic status of Erysiphe‒C. controversa association in Korea, isolates collected since 1987 were investigated and consequently identified as E. cornicola based on molecular‒phylogenetic analyses and new morphological traits. To our knowledge, this is the first study to confirm the presence of this powdery mildew in Korea.