Study On Synergistic Mechanism Of Compound Biocontrol Bacteria Against Apple Canker Disease

Apple canker disease is an infectious disease caused by apple black rot fungus(Valsa Mali Miyabe et Yamada).It has spread widely in China and gradually become a disease with frequent occurrence in the investigation of fruit tree diseases in Inner Mongolia in recent years.The economic development of apple industry is seriously affected.At present,the prevention and control of apple putrel mainly rely on chemical agents in agricultural production,and chemical agents are easy to cause many problems such as bacterial resistance and environmental pollution.As more and more antagonistic microorganisms were discovered,the application of microorganism to control apple canker disease has a broad development prospect.In this study,based on the stability measurement of apple canker disease strain,the composite strain was constructed and its control effect on apple canker disease was measured.The results are as follows:1.Using an existing pathogenic fungus,C.Mali QH2,Bacillus velezensis BXZ3-6,L-1,LZ1-4,PGB-8,PCL-10,ST-8 and inducer Bacillus endophyticus BHC6-7,Pseudomonas Moraviensis BHC6-11,Arthrobacter sp BHC6-18,Stenotrophomonas Maltophilia BXZ1-1 The induced activities of iron,phosphorus,nitrogen,potassium,IAA and ACC producing deaminase were measured by plate antagonism method.The control efficiency of 6 biocontrol strains was measured in vitro.The stability test of 10 active strains showed that the aseptic fermentation broth BXZ3-6,LZ1-4,ST-8,BHC6-7 and BHC6-18 had the strongest salt tolerance,LZ1-4 and BHC6-18 had the best alkali resistance under the condition of PH≥11,and BXZ3-6 and L-1 had the best acid resistance.After different time of uv and temperature treatment,it was found that the effect on the sterile fermentation filtrate of biocontrol strain was little,and they could all grow.2.On the interaction between active strains and nutrient utilization of determination,analysis that nutrient use properties and interaction has certain relevance,the fast growth of strains of pathogenic bacteria of antagonist activity is higher,and the antagonism of other bio-control strains with high activity,and relative to other strains had a lower risk of antagonism.The competition between available nutrient species and nutrient use intensity varied,with a variation of 0.700-1 and 0.530-1,respectively.3.Through experiments on apple branches,it was found that the control effect of single strain L-1 and BXZ3-6 reached 89.31% and 87.04%,which was better than that of other target strains.In addition,the control effect of 26 combinations of compound strains was better than that of single strain.Among them,L-1*BHC6-18 compound strain had the best treatment effect up to 100%.