First Report of Powdery Mildew Caused by Erysiphe macleayae on leaves of Macleaya microcarpa in the Czech Republic

Abstract

Plume-poppy (Macleaya R. Br.), a member of the Papaveraceae family, is typically grown in gardens as a subject for flower arranging. In September 2015, during a survey of powdery mildew occurrence in the Medicinal Herbs Centre of the Faculty of Medicine and the Botanical Garden of the Faculty of Science of Masaryk University in Brno (Czech Republic), extensive powdery mildew symptoms were found in small-fruited plume-poppy (Macleaya microcarpa (Maxim.) Fedde) plants (Fig. 1). In most plants, powdery mildew mycelium covered large portions of both the upper and the lower side of the leaves. Representative specimens were deposited in the herbarium of the Department of Botany, Faculty of Science, Palacký University, Olomouc. Both the anamorph and the teleomorph stages of the fungus were found. At least 30 independent measurements were obtained to describe its morphological characteristics of the fungus. We observed cylindrical to ellipsoid conidia (25-40 × 12-18 µm; length/width ratio 1.5-3.2), which matured ...