采用砂培、水培和室内培养等试验方法研究了连作大豆根分泌物对根腐病病原菌的化感作用 .结果表明 ,与对照相比 ,连作和轮作大豆根分泌物对半裸镰孢菌、粉红粘帚菌和尖镰孢菌尤其是对半裸镰孢菌的生长有明显的化感促进作用 ,差异达显著或极显著水平 .低浓度时 ,连作大豆根分泌物对半裸镰孢菌和粉红粘帚菌生长的化感促进作用明显大于轮作大豆 ,差异达显著水平 .同一茬口 ,高浓度根分泌物对半裸镰孢菌生长的化感促进作用小于低浓度 ,而且在连作大豆中差异达显著水平 .与对照相比 ,高浓度的邻苯二甲酸和丙二酸 (L5和B5)对半裸镰孢菌、粉红粘帚菌和尖镰孢菌尤其是对半裸镰孢菌的生长有化感抑制作用 ,差异达显著或极显著水平 .而低浓度的邻苯二甲酸和丙二酸对半裸镰孢菌、粉红粘帚菌和尖镰孢菌的生长有化感促进作用 ,部分差异达显著水平 The allelopathic effects of continuous cropping soybean root exudates on the pathogen of root rot were studied using sand culture, hydroponics and indoor culture experiments.The results showed that compared with the control, the root exudates of soybean continuous cropping and rotation were insensitive to Fusarium solani, Fusarium oxysporum and Fusarium oxysporum had a significant allelopathic effect on the growth of Fusarium solani, and the difference was significant or extremely significant.When the concentration was low, the effects of continuous root exudates on Fusarium solani and pink Allelopathic effect of growth of B. viscosum was significantly greater than that of rotation soybean, and the difference was significant at the same level.Under the same stubble, the allelopathic effects of high concentration root exudates on the growth of Fusarium solani was lower than that of low concentration, but the difference was significant Level.Compared with the control, the high concentration of phthalic acid and malonic acid (L5 and B5) had a chemopathic effect on the growth of Fusarium solani, Pinky flounder and Fusarium oxysporum, especially against Fusarium solani Inhibition, the difference was significant or very significant level.However, the low concentration of phthalic acid and malonic acid had the allelopathic effect on the growth of Fusarium solani, Pinky, and Fusarium oxysporum, and some differences were significant Level