Biological characteristics of Ampelomyces quisqualis hyperparasite of tickseed powdery mildew

The hyperparasite(Ampelomyces quisqualis Ces.) of tickseed powdery mildew(Sphaerotheca fusca) could produce spores and grow on PSA, OA and PDA, among them PSA was the best. The mycelia grew badly on A HA and Czapek, and no spores produced on Richard medium. The optimal temperature and pH value were 20-25℃ and 4-9, respectively. Light promoted sporulation and germination while darkness advanced mycelia growth. There were six kinds of carbon sources including mannitol and hydrolazed lactose, which were better for the mycelium growth and air-dried weight, mannitol was the best and soluble starch was the worst. Among glucose, sucrose and fructose, glucose was the best for sporulation. As to nitrogen sources, peptone and yeast extract were better for mycelia growth, air-dried weight and sporulation. The optimal temperature and relative humidity for spore germination were at 10～25℃ and 65%～100% respectively, but the best in water drop. The spore could not germinate below 50%RH. The optimal pH value was 5～7, The spore could not germinate at pH lower than 2 or higher than 10.