Study On The Selection Of Composite Bacteria For Growth-promoting And Resistance To Bacterial Wilt And Their Applications

Microbial fertilizer as a new type of fertilizer, applied into the soil, through its rapid propagation of the particular strain that can fix atmospheric nitrogen, release a fixed state of soil phosphorus and potassium, then make the environment fully tapped the potential of nutrients and create a good crop soil environment. It’s important to reduce fertilizer consumption and pollution, and improve crop quality. In particular, the research of the composite microbial fertilizer with property of the insecticide-fertilizer which can fix nitrogen, resistant crop disease and promote growth health played a decisive role in sustainable agricultural development.In this study, ten multi-function strains as the research objects, we measured the fixing strain energy, the antagonistic abilities among the bacteria, antimicrobial activity against R. Solanacearum and combined potted single-strain test results to build a better multi-functional complex microorganisms, and then through the composite bacteria effective screening test pot to get the best test composite bacteria and provide the basis for further field trials. In this paper, the main results were summarized as follows:(1) Nitrogen-fixing bacteria on the functional activity assay, improved Waxman nitrogen-free medium for 77 days after the determination of 5 results, functional bacteria GDI, GD8, XH, KC, JD, DN3, DN4 had a certain nitrogen fixation effects, which were better DN4, DN3,GD1,GD8.(2) For determination of functional antagonism between bacteria, except with some strains XH (KC, DY, etc.) slightly antagonistic, the antagonism between the other strains were not obvious; by the determination of antagonistic bacterial wilt test to determine the function of bacteria CB, KC, DY. XH, DN3, GD8, DN4, GD1 and so had different antagonistic effects, including CB, KC, DY, XH effect was remarkable.(3) Effect measured by pot experiment single strain available, functional indicators of strain DN3 in improving soil, plant growth promotion, plant disease resistance had a significant effect in three areas, in order to build the core of multi-functional compound bacteria strains. Functional bacteria CB, NJ, JD promoted the strains in soil improvement, CB, GD8 for the plant growth promoting strains, KC, DY optimum for the plant disease-resistant strains. Combined (1), (2) test results, build compound bacteria:Cl (DN3/CB/GD8/KC), C2 (DN3/CB/DY/NJ).(4) Measured by the composite effect pot test agents available, regardless of complex agents in the soil microenvironment C2 modified, or in the plant growth-promoting bacteria effects on disease resistance are significant. The beneficial microorganisms played an enormous role in the soil, and a variety of beneficial microorganisms could not only promote the transformation of soil nutrients but also regulate the microbial flora, then achieved the effects of growth promotion and disease resistance of plant. The test results were significantly better than chemical fertilizer and single-function bacteria, we speculated that synergistic interaction may exist among various function microbes.