First record of leaf rust caused by Melampsora populnea on Populus alba × glandulosa in Korea.
In September 2006, leaf rust was found in a plantation of the poplar hybrid (Populus alba × Populus glandulosa) at Anyang, Gyeonggi province, Korea Republic. Initial symptoms were small orange pustules (uredinia) of approximately 2 mm in diameter on the undersides of leaves, which enlarged and became darker in colour. Tiny yellow specks of approximately 2 mm in diameter appeared concurrently on the upper sides of leaves, merging to become brown lesions of approximately 2-5 mm in diameter. The uredinial state of this rust under light microscopy and scanning electron microscopy had the morphology of Melampsora populnea. This is thought to be the first record of M. populnea as a pathogen of the poplar in Korea.