First Report of Powdery Mildew Caused by Golovinomyces orontii on Common Poppy in Korea

In Korea, common poppy (Papaver rhoeas L.; Papaveraceae) was introduced in the 1990s and has been widely planted for ornamental purposes. In June 2013, the common poppies planted in the shady corner of a garden in Iksan, Korea, were found infected by a powdery mildew. The same symptoms were found on common poppies in several additional localities of Iksan and Hongcheon, Korea, in 2014. Voucher specimens were deposited in the Korea University Herbarium (KUS-F27314, F27322, F27839, F27930, and F27951). Symptoms began as circular to irregular white patches with or without purplish-brown discoloration of the lesion, which subsequently showed abundant hyphal growth on both sides of the leaves and stems, causing premature senescence. Appressoria on the mycelium were nipple-shaped. Conidiophores were arising laterally from hyphal mother cells, 120 to 250 × 10 to 12 μm, and produced 2 to 4 immature conidia in chains with a sinuate outline. Foot-cells of conidiophores were 42 to 85 μm long and characterized by the...