Effects Of Root Exudates Of Reverse Cropping Crop On Potato Fusarium Oxysporum

Potato blight is a serious harm of soil-borne diseases caused by Fusarium oxysporum, the disease is increasing year by year in Inner Mongolia potato-growing areas, lacking of effective control measures at present. The reasonable rotation of non-host crop is an important method to control the soil-borne diseases. To this end. by indoor antibacterial test, collecting corn, wheat, sunflower, soybean, canola five kinds of crops root exudates with water culture research on the effect on potato Fusarium oxysporum. revealing the relationship of between the root exudates and pathogenic microorganisms, provides the theoretical basis to produce a reasonable crop rotation regulation. The main research results as follows:1. The rosilts of soil bacterial assay shows that five crops of corn, wheat, sunflower, soybean and rape are not infected by potato Fusarium oxysporum.2. Mycelium growth rate method test show, five kinds of crops root exudates can inhibit mycelium growth of potato Fusarium oxysporum, but there are differences:corn root exudates has the strongest inhibitory’effect among the 5 kinds of plant, wheat second place, rape’s inhibitory effect is the weakest. With the passage of treatment time, inhibition rate of wheat and soybean root exudates is first increase and then decreases; however inhibition rate of corn, sunflower and rape root exudates increase as time prolonged, and the speed of rape increased rapidly3. Spore germination test show, five kinds of crops root exudates on spore germination of potato Fusarium oxysporum show different degree of inhibitory action, germination inhibition rate of sunflower root exudates is highest, corn root exudates second place; however germination inhibition rate of soybean root exudates is the weakest.4. Five kinds of crops root exudates on the spore production of potato Fusarium oxysporum show different degree of inhibitory action. The sporulation inhibition rate of Corn root exudates is the highest; the sporulation inhibition rate of sunflower root exudates is second, the sporulation inhibition rate of soybean root exudates is lowest.5. Five kinds of crops root exudates on toxin production of potato Fusarium oxysporum have certain inhibition, the higher the root exudates concentration, the stronger the inhibitory effect. Potato tissue culture seedling pathogenicity test with the toxins of bacteria, the results show that, disease index of tissue culture seedling treated by sunflower root exudates is lowest, followed by rape root exudates, wheat root exudates is highest.