大豆连作土壤有机化合物对大豆根腐病菌生长的影响

采用田间试验、生物模拟试验及化学分析等方法,研究了大豆连作土壤有机化合物(糖、氨基酸、有机酸)对大豆根腐病菌的影响.结果表明:轮作、连作大豆土壤糖组分对半裸镰孢菌、粉红粘帚菌、尖镰孢菌的生长多表现出低浓度促进高浓度抑制的规律,低浓度糖组分对粉红粘帚菌、尖镰孢菌生长的促进作用,连作显著高于轮作.轮作、连作土壤氨基酸组分对半裸镰孢菌、粉红粘帚菌、尖镰孢菌的生长多表现出显著的促进作用.轮作、连作土壤有机酸组分对上述三种病原菌生长多表现出显著促进作用,但连作高浓度有机酸组分能显著抑制粉红粘帚菌生长.上述结果表明,大豆连作土壤有机化合物与根腐病发生存在极密切关系,它们是根腐病严重发生的重要物质诱因.

INFLUENCE OF THE ORGANIC COMPOUNDS IN CONTINUOUS CROPPING SOYBEAN ON PATHOGENIC OF ROOT ROT

Influence of the organic compounds in continuous cropping soybean on pathogenic fungi of root rot were studied by field experiment and biology simulating experiment and chemical analysis method .The water soluble carbohydrates from rotational and continuous cropping soil showed a rule that at low concentrations they promoted the fungus growth but at high concentrations inhibition occurred. At low concentrations, the water soluble carbohydrates from continuous cropping soil showed much stronger promotion on the growth of Fusarium semitectum and Gliocladium roseum than those from rotational cropping soil. The water soluble amino acids from rotational and continuous cropping soil improved the growth of Fusarium oxysporium, Fusarium semitectum, Gliocladium roseum significantly. The water soluble organic acids from continuous and rotation cropping soil at low concentrations mostly promoted the growth of Gliocladium roseum, Fusarium oxysporium and Fusarium Semitectum significantly, while at high concentration organic acids from continuous cropping soil inhibited the growth of Fusarium oxysporium. The results above showed that water soluble carbohydrates, amino acids and organic acids from continuous cropping soybean had significantly close correlation with root rot.