Isolation And Identification Of Biocontrol Bacteria Of Peanut Pod Rot And Field Control Of Microbial Fertilizer

In recent years,peanut pod rot has become an important soil borne disease in China.This study Multifunctional rhizosphere microorganisms were isolated and identified peanut to prepare bioorganic fertilizer(BF),and multifunctional complex microorganisms were constructed to prepare microorganisms soilconditioner(MS).The function of BF and MS were verified by pot experiments,greenhouse plot experiments and field experiments.The prevention and control mechanism of microbial fertilizer on peanut pod rot was preliminarily revealed by microbial diversity analysis.Three multifunctional strains XJ-32,GF-32a and GD-16 were screened from 89peanut rhizosphere microbial strains.Strains XJ-32,GF-32a and GD-16 were identified to Priestia megaterium,Paenibacillus mucilaginosus and Priestia megaterium based on morphological,molecular biological,and physiological&biochemical characteristics by Multiphase Classification Method.P.megaterium XJ-32 showed function of promoting growth,degrading autotoxins and biocontrol.P.mucilaginosus GF-32a showed significant function of degrading autotoxins and promoting growth.P.megaterium GD-16 showed significant function of promoting growth and degrading autotoxins.Bioorganic fertilizer with P.megaterium XJ-32≥50 million CFU/g(BF-32)was prepared for Pot experiments and greenhouse plot experiments showed that 40kg/667m~2 of BF-32 can significantly promote seedling growth and yield increase.Field experiments showed the combined application of 40 kg/667m~2 BF-32 and 25kg/667m~2 calcium fertilizer(Calcium Ammonium Nitrate or Calcium Nitrate)resulted in a control efficiency of 85%-89%for peanut pod rot and a yield increase rate of 26%-28%Microorganisms soilconditioner was prepared with P.mucilaginosus GF-32a≥50million CFU/g,Bacillus amyloliquefaciens GF-3≥50 million CFU/g and P.mucilaginosus GD-16≥50 million CFU/g,for short MS-32a.Pot experiments and greenhouse plot experiments showed that 40 kg/667m~2 of MS-32a can significantly promote seedling growth and yield increase.The control efficiency for peanut pod rot up to 96.23%and yield increase rate was 42.34%in field experiments.Microbial diversity analysis of rhizosphere soil showed that both BF-32 and MS-32a enhanced the correlation and interaction relationship between rhizosphere bacteria and fungal,increased the relative abundance of beneficial microorganisms,reduced the relative abundance of main pathogenic fungal,and reduced the occurrence of peanut pod rot.This study prepared two multifunctional microbial fertilizers,and provided theoretical basis and technical support for prevention and control of peanut fruit rot.