Abstract: This study aims to clarify the biological activity and synergistic effects of seven biopesticides against Fusarium proliferatum in Dendrobium officinale，and provide reference for green and efficient control of D.officinale soft rot disease in field.Mycelium growth inhibition method and field efficacy test were used to evaluate indoor toxicity and synergistic effects of seven biological pesticides against F.proliferatum.The results showed that all the seven agents had different inhibitory effects on mycelial growth of F.proliferatum，among them eugenol，osthole，tetramycin and shenqinmycin had better inhibitory effects，with EC₅₀ values of 0.38，4.92，0.32 and 1.85 μg/mL，respectively.The synergistic effect showed that different drug combinations also had different inhibitory effects on mycelial growth of F.proliferatum，among them eugenol+shenqinmycin（effective mass ratio was 1∶3） and tetramycin+shenqinmycin（effective mass ratio was 9∶1）had better inhibitory effects，with co⁃toxicity coefficient（CTC）values of 195.65 and 145.76，and EC₅₀ values of 1.35 μg/mL and 1.13 μg/mL，respectively.Eugenol+osthole（9∶1），osthole+shenzimycin（1∶1），and osthole+tetramycin（9∶1） also had better inhibitory effects on mycelial growth of F. roliferatum，with CTC values of 325.38，236.46 and 541.53，and EC₅₀ values of 2.86，1.23 and 0.75 μg/mL，respectively.Field and pot test showed that synergistic combinations had a good control effect on soft rot of D.officinale，when effective mass ratios of eugenol+osthole，osthole+shenzimycin，and osthole+tetramycin were 9∶1，1∶1，9∶1，respectively.In conclusion，all the seven biopesticides and their combinations have better control effects on soft rot of D.officinale，which could be used for controlling soft rot in field.

Key words: Dendrobium officinale, Fusarium proliferatum, Biopesticide, Sensibility, Synergistic effect

摘要： 为明确7种生物药剂对铁皮石斛层出镰刀菌（Fusarium proliferatum）的生物活性及其协同作用，为田间绿色高效防控铁皮石斛软腐病提供参考，采用菌丝生长速率法测定了7种生物药剂对铁皮石斛层出镰刀菌的室内毒力及其协同作用，并通过盆栽试验和田间试验验证防效。结果表明，7种生物药剂对铁皮石斛层出镰刀菌菌丝生长均具不同的抑制作用，其中丁子香酚、蛇床子素、四霉素、申嗪霉素的抑菌效果较好，EC₅₀值分别为0.38、4.92、0.32、1.85 μg/mL。协同作用结果显示，不同药剂组合对铁皮石斛层出镰刀菌菌丝生长的抑制作用有一定差异，其中丁子香酚+申嗪霉素和四霉素+申嗪霉素分别以有效质量比为1∶3 和9∶1 时增效作用明显，其共毒系数（CTC）分别为195.65 和145.76，EC₅₀值分别为1.35 μg/mL和1.13 μg/mL；而丁子香酚+蛇床子素、蛇床子素+申嗪霉素、蛇床子素+四霉素3个组合分别以有效质量比为9∶1、1∶1、9∶1时增效显著，其CTC分别为325.38、236.46、541.53，EC₅₀值分别为2.86、1.23、0.75 μg/mL；且盆栽试验和田间试验表明，丁子香酚+蛇床子素、蛇床子素+申嗪霉素和蛇床子素+四霉素3个组合分别以有效质量比为9∶1、1∶1和9∶1时对铁皮石斛软腐病均具有较好的防治效果。可见，7种生物药剂及其组合对铁皮石斛软腐病均具有一定的防治效果，可用于田间铁皮石斛软腐病的防治。

关键词: 铁皮石斛, 层出镰刀菌, 生物药剂, 敏感性, 协同作用