Occurrence of Fruit Rot of Watermelon (Citrullus Lanatus) Caused by Sclerotium rolfsii

Kwon, Jin Hyeuk; Park, Chang Seuk

Research in Plant Disease 2009;15(1):51-53.
Published online April 30, 2009.

Sclerotium rolfsii에 의한 수박 흰비단병 발생

권진혁, 박창석

Occurrence of Fruit Rot of Watermelon (Citrullus Lanatus) Caused by Sclerotium rolfsii

Jin Hyeuk Kwon, Chang Seuk Park

Abstract

The fruit rot of watermelon (Citrullus lanatus) occurred sporadically in the farmers field at Chojeondong, Jinju city, Korea, in 2007. The typical symptom was water-soaked, brown on the fruit, and than infected fruits were mostly rotted. White mycelial mats were spread over lesions, and then sclerotia were formed on fruit and near soil line. The sclerotia were globoid in shape, 1~3 mm in size and white to brown in color. The optimum temperature for mycelial growth and sclerotia formation on PDA was 30oC and the hyphal width was 4~8 μm. The typical clamp connections were observed in the hyphae of the fungus. On the basis of mycological characteristics and pathogenicity to host plants, this fungus was identified as Sclerotium rolfsii. This is the first report on the fruit rot of watermelon by S. rolfsii in Korea.

Key Words: Citrullus Lanatus, Fruit rot, Sclerotium rolfsii, Watermelon