The results showed: the brown symptom of soybean root both appeared after the concentrated toxin and toxin were put in the sterilization or nonsterilization soil, and it was similar to the symptom caused in the natral environment.

• 试验结果显示：非灭菌土、无菌土中加入代谢产物浓缩液和代谢产物滤液后，均可导致大豆根部变褐症状，其症状与田间自然条件下大豆根腐病症状类似。