Abstract: The effects of oxidative stress on hyphal growth and chlamydospore production in Clonostachys rosea 67-1was investigated through adjusting ventilatory volume and adding various kinds of reactive oxygen（O2-,H2O2 and OH·）. The results showed that the effects of oxidative stress on fungal mycelia were different from that on chlamydospores. When aeration rate was low,the growth status of the fungus changed;with the increasing of loading volume,the branches of mycelia reduced,and the yield of chlamydospores decreased sharply. Reactive oxygen at certain amount affected the formation of chlamydospores during 67-1fermentation. When 5-6 mmol/L H₂O₂ was added before inoculation,the production of chlamydospores significantly increased,and the growth and sporulation of 67-1were completely inhibited while the concentration was 9 mmol/L. The oxygen-tolerance of the fungus was remarkably enhanced when H₂O₂ was supplied at 16 h after inoculation. Menadione inhibited chlamydospore formation when added into the fermentation liquor directly,but adding 350 µmol/L menadione significantly promoted fungal sporulation after incubated for 16 h. In Fe²⁺-H₂O₂ system,high oxygen stress in different time significantly increased chlamydospore production（P < 0.05）.

Key words: Clonostachys rosea, oxidative stress, active oxygen, chlamydospore, fungal growth