Screening Of Antagonisms And The Application Of Their Antibiotic Activities Against The Soilborne Pathogens

Soilborne pathogens heavily affect plant growth and crop yield even in modernagriculture. The excessive application of chemical pesticides is not only producingpesticide—resistant pathogens, but harming the environment and threatening thehealth of human beings. The use of biological control agents (BCA) may provide anenvironmental friendly alternative to chemicals for plant disease control. Therefore, Itwould be useful to explore new biological control agents to control pathgens in cropplants.4 bacteria strains were isolated from different plant rhizosphere soils. T-0491showed antibiotic activities to 4 kinds of phytopathogens, such as Rhizoctonia solani,Sclerotinia sclerotiorum, Fusarium oxysporium and Verticillium dahliae. Green houseand field tests revealed that it greatly increased the yields of watermelon. 01—74,01—483 and 01—718 showed antibiotic activities to Ralstonia solanacearum.Theywere more effective on controlling tomato bacterial wilt than the current biologicalcontrol agents. Based on the phenotypic characteristics,01—718 was Pseudomonas sp.and others were Bacillus sp..At present, the study of biological control agents is concentrate on Bacillus andother available bacteria. But it is hard to spread because of the instability on fields.Our study was trying to find more persistent and more stable biological control agents.Disposal on the seeds or the little seedings before sowing, in order to preventpathogenic microorganism intruding more effectly and more economically.consequently, crop yield would be ensured.