First Report of Gray Mold Disease on Endangered SpeciesCypripedium japonicum

Abstract

Cypripedium japonicumis known to be the indigenous plant to Korea, Japan, and China. However,C. japonicumrepresents the most critically endangered plant species in South Korea. The plant is esthetically pleasing due to its flower, which is larger than any other orchidaceous species. Disease symptoms relating to gray mold were observed onC. japonicumin May 2019. The suspected pathogen was successfully isolated from the symptomatic leaf tissue and conducted a pure culture of the fungi. The conidia formed consisted of a colorless or light brown single cell, which was either egg or oval-shaped with a size of 7.1 to 13.4 x 5.2 to 8.6 mu m. Molecular phylogenetic relationship analysis was also confirmed that the pathogen concerned belonging to the family ofBotrytis cinerea.Therefore, the findings confirmed that the pathogen isolated fromC. japonicumwas consistent with the unique properties ofB. cinerea.