First Report of Botryosphaeria parva Causing Stem Blight on Rubus crataegifolius in Korea

Abstract

Listen

Translate article

which is commonly found in the mountainous areas of Korea, Japan, and northeast China. R. crataegifolius has been used as food and traditional medicine for many years in this region by its various bioactivities such as immunological and antioxidant activities (Moon et al., 2011; Ni et al., 2009; Zhang et al., 2010). According to the usefulness of R. crataegifolius, the importance of disease management of R. crataegifolius has increased in Korea (Korea Forest Service, 2015). Several pathogens that infect R. crataegifolius have been reported in Korea, including Septoria rubi, Rhizopus stolonifer, Phragmidium griseum, and Phytoplasma (Kim et al., 2009). In July 2015, stem blight symptoms were observed in a field of R. crataegifolius in Pohang, Gyeongbuk province, Korea. Early in the course of the disease, plants showed dark red spots on stems; these spots expanded to black lesions associated with stem blight (Fig. 1A). As the disease progressed, pycnidia appeared on the stem lesions (Fig. 1B). The blight eventually spread to the leaves and resulted in plant death. A fungus, the presumed causal agent, was isolated from the diseased plant and designated as PPL02. The infected part of the stem was cut into small pieces and the surface of pieces was sterilized with 1% NaOCl for 1 minute and washed three times with 70% ethanol. The surface-sterilized pieces were placed onto potato dextrose agar (PDA) medium and incubated at 25C. For isolation of a pure culture, hyphal tips of mycelia on the PDA medium were cut and transferred to fresh PDA plates. Open Access Res. Plant Dis. 22(2): 116-121 (2016) http://dx.doi.org/10.5423/RPD.2016.22.2.116