First report of cane and leaf rust on Rubus fruticosus caused by Kuehneola uredinis in Korea.
In September 2011, a rust disease affecting approximately 90% of the leaves of several R. fruticosus plants in Andong, Korea, was observed. Pustule formation occurred on cane surfaces and on the undersurfaces of leaves, with yellowing, reddening, and necrosis on the corresponding upper leaf surface. Leaf distortion and senescence also occurred. For light and scanning electron microscopy, uredinia were detached from leaf lesions. The development of uredinial colonies with abundant sporulation was observed. The echinulate urediniospores were yellowish or occasionally pale brown, with a globose or subglobose shape. Telia were a floccose and pale yellowish-buff or almost white. Teliospores were 4- to 7-celled. Cells were trapezoidal-cylindrical. The pathogen was identified as K. uredinis based on morphology, and this identification was confirmed by internal transcribed spacer analysis. This is thought to be the first report of an outbreak of cane and leaf rust on R. fruticosus caused by K. uredinis in Korea.