Treatment of corn seeds with Bacillus subtilis strain B20-006,a potential biocontrol agent,had no effect on type of endophytic bacteria on corn.However,it stimulated endophytic bacterial reproduction in the plants.B20-006 did not affect the original population of endophytic bacteria in corn roots in early stage.In late stage,population of endophytic bacteria in corn roots treated with the bacteria was significantly higher than CK.Colonization of the bacteria in corn roots would benefit the micro-ecological resistance of cultivars against the diseases.The results suggested that strain B20006 could enhance the percentage of antagonistic endophytic bacteria against Rhizoctonia solani.The percentage in the resistant cultivar,Lianyu 11 was higher than in the susceptible one,Lianyu 13.
Endophytic bacteria B20-006,an antagonistic microbe,was applied to coat maize seeds and resulted in 67.9% control effect on maize sheath blight caused by Rhizoctonia solani.Moreover,B20-006 was ensured the ability to penetrate roots,and in turn move along vascular elements of maize plants.For further study of biocontrol mechanism of the antagonistic agent,the changes of major defensive enzymes(PAL,POD,SOD and EST) in specific activity were assayed in plants due to interaction between B20-006 and host maize.
