Identification of Neocosmospora ipomoeae causing tomato stem rot in Korea

Abstract

Severe stem rot in hydroponically grown tomatoes was observed in Jinju, South Korea in early spring, 2016. Initial symptoms were water-soaked lesions on the lower stems, near the collar. Infected tomato plants gradually wilted leading to death of the plants. Advanced lesions were brown in color. Fungal isolates were identified by morphology and sequences of the gene encoding translation elongation factor 1-alpha (TEF1-alpha). To fulfill Koch's criteria, pathogenicity tests were completed on potted 2-month-old tomato plants. The causal fungus was identified as Neocosmospora ipomoeae. This is the first report of tomato stem rot caused by Neo. ipomoeae in Korea.