Topic F: Infection and Pathogenesis : New Cladobotryum Species causing Cobweb Disease in Beech Mushroom

Cobweb disease caused by Cladobotryum species is harmful in mushroom cultivate farms. It had been reported as C. mycophilum on Agaricus bisporus, Pleurotus eryngii and C. varium on Flammulina velutipes, Hypsizigus marmoreus, P. eryngii in Korea. In 2013, cobweb disease were observed on beech mushroom cultivate farm in Cheongdo-gun, Korea. Fruit bodies were covered with white mycelia and finally, rotten. The causal agents were identified Cladobotryum sp. based on morphological characteristics. These isolates were obtained sequences of molecular marker as ITS, RPB1, RPB2 and TEF1 regions. Phylogeny tree was prepared by Neighbor-joining method using the combined sequence dataset. As a result, these isolate were clustered as Cladobotryum asterophorum. Pathogenicity of 3 different mushrooms as H. marmoreus, F. velutipes and P. eryngii revealed that all mushrooms were appeared cobweb symptoms. But it doesn`t produced massive spores on fruit bodies. This Cladobotryum species is a new pathogenic agent in beech mushroom and is possible to attack other mushrooms.