Occurrence and Pathogenicity of Verticillium Wilt on Chrysanthemum Caused by Verticillium dahliae

Han, Kyung Sook; Park, Jong Han; Lee, Jung Sup; Seo, Sang Tae; Cheong, Seung Ryong

Research in Plant Disease 2007;13(1):15-19.
Published online April 30, 2007.

Verticillium dahliae에 의한 국화 반쪽시들음병 발생과 병원성

한경숙, 박종한, 이중섭, 서상태, 정승룡

Occurrence and Pathogenicity of Verticillium Wilt on Chrysanthemum Caused by Verticillium dahliae

Kyung Sook Han, Jong Han Park, Jung Sup Lee, Sang Tae Seo, Seung Ryong Cheong

Abstract

A wilt disease on the greenhouse-grown chrysanthemum occurred at Kumi, Masan and Busan, Korea in 2003~2005. Symptoms of wilting, yellowing, and marginal burning started from lower leaves and progressed upward. Early symptoms often appeared on one side, involving only one part of the plant or one side of individual leaves or stems without a vascular discoloration. Vascular tissues of the infected leaf-base``s discolored to brown. Fungal isolates obtained from discolored tissues were identified as Verticillium dahliae based on its cultural and morphological characteristics. The fungus showed whitish to creamy colony pattern with abundant dark brown to black elongated microsclerotia on PDA. Conidiophores were verticillately branched and conidia were ellipsoidal to sub-cylindrical shape, and measured as 2.5~8.8 × 2.0~3.8 μm. Pathogenicity tests by root dipping resulted in similar symptoms observed in the naturally infected chrysanthemum in fields.

Key Words: Chrysanthemum, Pathogenicity, Verticillium dahliae