Sclerotium blight of Phalaenopsis Orchids Caused by Sclerotium rolfsii in Korea

Han, Kyung Sook; Lee, Seong Chan; Han, You Kyoung; Kim, Su; Park, Jong Han

Research in Plant Disease 2011;17(3):402-404.
Published online December 30, 2011.

Sclerotium rolfsii에 의한 팔레놉시스 흰비단병

한경숙, 이성찬, 한유경, 김수, 박종한

Sclerotium blight of Phalaenopsis Orchids Caused by Sclerotium rolfsii in Korea

Kyung Sook Han, Seong Chan Lee, You Kyoung Han, Su Kim, Jong Han Park

Abstract

The Sclerotium blight was found on Phalaenopsis spp. at Dong-du-cheon city, and Hwa-seong city, Gyenggido, Korea in September 2009. The symptom included yellowing on lower leaves and wilt of a whole plant. Severely infected plants were blighted and died eventually. White mycelial mats appeared on the surface of basal stem and bulbs and the sclerotia were formed on stems, roots, and sphagnum moss. The sclerotia were spherical, 1.3 mm and white to brown. The optimum temperature for the growth and sclerotia formation was 25.30oC on PDA. On the pathogenicity test, the first symptom appeared 5 days after inoculation and developed to severe stem rot and blight. On the basis of mycological characteristics and pathogenicity, the causal fungus was identified as Sclerotium rolfsii. This is the first report on the sclerotium blight on Phalaenopsis spp. caused by Sclerotium rolfsii in Korea.

Key Words: Blight, Phalaenopsis, Sclerotium rolfsii