First report of anthracnose crown rot caused by Colletotrichum siamense on strawberry in Korea

Myeong Hyeon Nam1,*   Myung Soo Park2   Je hyeok Yoo1   Byung Joo Lee1   Jong Nam Lee3   

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Abstract

Anthracnose crown rot (ACR) has been observed in greenhouses during the nursery and harvest seasons in Gangwon Province, Korea. Infected plants showed black leaf spot, dark sunken pink conidial masses on petioles, wilting, and eventually death. Five isolates were obtained from the lesions of strawberry plants and were identified as a Colletotrichum gloeosporioides species complex based on their cultural and morphological characteristics. Multilocus sequence analysis of actin, calmodulin, chitin synthase, glyceraldehyde-3-phophate dehydrogenase genes, and internal transcribed spacer rDNA regions showed that the isolates formed a monophyletic group with the type strain of C. siamense. Pathogenicity tests were performed on the isolate, and Koch’s postulates were performed to verify the relationship between Colletotrichum sp. and the strawberry plant variety Seolhyang. The isolate was pathogenic to strawberry plants, which exhibited typical ACR symptoms. Based on morphological characteristics, pathogenicity, and DNA sequence analyses, the fungus isolated in Korea was identified as C. siamense. This is first time C. siamense has been confirmed in ever-bearing strawberry varieties in Korea.

Figures & Tables

Fig. 1.Anthracnose symptoms on strawberry of Colletototrichum siamense . (A) Strawberry plant with anthracnose crown rot girdling on a petiole. (B) Wilting plant. (C) Longitudinal section of an infected crown showing marbled reddish-brown necrosis. (D) Symptoms of artificial inoculation test with an isolate.