The study of biological characteristics on the hyperparasite of sphaerotheca fuliginea

The biological characteristics of the hyperparasite of cucumber powdery mildew fungus was studied systematically.The hyperparasite could produce spores and grow on PDA、PSA and OA media.Among them PSA is the best.The mycelium grew badly and no spore was produced on Czapek medium.Both on Richard and AHA media, the mycelium and spore were no growth and production. The results showed that the optimum temperature and pH value for the mycelial growth and sporulation were 20～25℃ and 8～9, respectively. Illumination had no effect on the linear growth of mycelium. Glucose,sucrose, fructose, starch, mannitol, maltose and hydrolactose all could be used, among them hydrolactose was the best for mycelial growth, glucose was the best for spore formation. Peptone ,Yeast extract, Glycin, KNO_3, (NH_4)_2SO_4、NH_4Cl ,Urea all could be used,among them yeast extract was the best for mycelial growth and urea was the worst one; yeast extract was the best for spore formation.The optimum temperature and relative humidity for spore germination were 10～25℃,95%～100%, respectively, but best in drops of water. The light was favourable for the spore germination.The optimum pH was 6～8. The spore could not germinate at pH lower than 2 or higher than 10. The lethal temperature of conidia was 60℃.