Study on Allelopathy of Root Exudations on Pathogenic Fungi Producing Root Rot in Continuous Cropping and Rotation Soybean

摘要

Allelopathy of root exudations on pathogenic fungi producing root rot in continuous cropping soybean was studied by sand culture, water culture and indoor culture experiments. The results showed allelopathy promotion of root exudations on the growth of Fusarium semitectum, Gliocladium roseum and Fusarium oxysporum, especially for Fusarium semitectum allelopathy promotion reached significant or very significant level (P<0.01) in continuous cropping and rotation soybean in contrast with the control. Allelopathy promotion of root exudations on the growth of Fusarium semitectum and Gliocladium roseum in continuous cropping soybean was significantly larger than that in rotation soybean and difference reached significant level (P<0.05) on low concentration condition. Allelopathy promotion of the high concentration root exudations on the growth of Fusarium semitectum was smaller than that of low concentration root exudations. Moreover difference reached significance level in continuous cropping soybean. Allelopathy inhibition of high concentration phthalic acid and propanedioic acid (L5 and B5) on the growth of Fusarium semitectum, Gliocladium roseum and Fusarium oxysporum, especially for Fusarium semitectum allelopathy promotion reached significant or very significant level (P<0.01) in continuous cropping and rotation soybean in contrast with the control. However, allelopathy promotion of low concentration phthalic acid and propanedioic acid on the growth of Fusarium semitectum, Gliocladium roseum and Fusarium oxysporum partly reached difference significant level.