Morphological And Molecular Characteristics Of Erysiphe Cornicola, A Powdery Mildew On Cornus Controversa

Morphological And Molecular Characteristics Of Erysiphe Cornicola, A Powdery Mildew On Cornus Controversa

In-Young Choi1*, Lamiya Abasova1, Joon-Ho Choi1, Ji-Hyun Park2, and Hyeon-Dong Shin1,3

1Department of Agricultural Biology, Jeonbuk National University, Jeonju 54896, Korea

2Department of Forestry, Environment, and Systems, Kookmin University, Seoul 02707, Korea

3Division of Environmental Science and Ecological Engineering, Korea University, Seoul 02841, Korea

*Email: iychoi@jbnu.ac.kr

In Korea, Cornus controversa and C. florida are known as hosts of Erysiphe pulchra (syn. Microsphaera pulchra) from the section Microspharea of the genus Erysiphe. Previously, M. pulchra on C. macrophylla and C. controversa was treated as M. pulchra var. japonica, based on slight morphological differences. Later, this variety was reduced to the synonym of E. pulchra. Subsequently, two Erysiphe species were associated with Cornus spp. globally in the last decade: E. tortilis distributed in Europe and Iran on C. alba, C. amomum, C. bretschneideri, C. mas, C. sanguinea, C. sanguinea subsp. australis, and C. sericea; and E. pulchra in Asia and North America on C. alternifolia, C. controversa, C. florida, C. kousa, and C. macrophylla. 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 Erysiphe cornicola. Currently, the host range of E. pulchra is confined to C. florida and C. kousa. To assess the taxonomic status of Erysiphe powdery mildew on C. controversa 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.