中文摘要：

目的利用本实验室丰富的内生真菌资源筛选出具有良好生物防治铁皮石斛软腐病的菌株，为开发内生真菌生物防治技术和大田应用打下基础。方法采用内生真菌与软腐病原菌PDA平皿对峙实验确定的18株内生真菌用于生物防治实验，先采用瓶苗共培养的方法确定对铁皮石斛苗致病力弱或具有促生长作用的菌株用于盆栽苗实验，进而确定内生真菌的生物防治效果。结果通过盆栽苗生物防治软腐病病原菌终极腐霉的实验研究，利用统计学分析确定了2株具有良好生物防治效果的内生真菌菌株4829和3952，铁皮石斛苗的存活率分别达到66．7％和60．5％。结论石斛属植物内生真菌具有良好的生物防治铁皮石斛软腐病效果。

英文摘要：

OBJECTIVE To screen out endophytic fungi isolates with good biological control against damping-off in Dendrobium candidum seedlings among the isolates owned by our laboratory, thus to lay a foundation on developing biological control technique and field application. METHODS Eighteen isolates of endophytic fungi identified by the PDA Petri dish confrontation experiment and athogen of damping-off were used in the biological control experiment. Co-incubation in bottles was conducted to screen out isolates with weak pathogenic and growth promoting effect on Dendrobium candidum seedlings. The chosen isolates were then enrolled in the potted seedlings experiment to determine their biological control effect. RESULTS Isolates 4829 and 3952 were confirmed to have good bio- logical control effect by statistical analysis. The survival rates of Dendrobium candidum seedlings reached 66.7% and 60.5% respec- tively. CONCLUSION Endophytic fungi isolated from Dendrobium sp. shows good biological control against Dendrobium candidum damping-off.