Complex microbial inoculant for preventing and treating clubroot of rape

Abstract

The invention relates to the field of microorganisms, and discloses a complex microbial inoculant for preventing and treating clubroot of rape. Comprising the following raw materials in parts by weight: 10 to 12 parts of acid-resistant bacillus, 12 to 15 parts of pseudomonas fluorescens PF-5, 8 to 10 parts of bacillus mucilaginosus, 5 to 7 parts of halophilic bacillus, 8 to 10 parts of bacillus amyloliquefaciens, 12 to 15 parts of trichoderma atroviride ReTv2, 6 to 8 parts of azotobacter chroococcum, 10 to 12 parts of chitosan-gamma-polyglutamic acid microspheres, 12 to 15 parts of diatomite and 8 to 12 parts of humic acid. And 2-4 parts of algal polysaccharides. The living space of plasmodiophora brassicae is preempted by the acid-resistant bacillus; the pseudomonas fluorescens PF-5 directly strikes pathogenic bacteria and stimulates the defense system of the oilseed rape; the bacillus amyloliquefaciens releases a plurality of antibacterial substances; the trichoderma atroviride ReTv2 rapidly destroys the structure of the plasmodiophora brassicae in a manner of hyperparasitism and exoenzyme secretion.

Description

Technical Field

[0001] The invention relates to the technical field of microorganisms, in particular to a composite bacterial agent for preventing and treating rapeseed clubroot. Background Art

[0002] As a basic industry of the national economy, the healthy development of agriculture is of vital importance. In the field of rapeseed cultivation, with global climate change and changes in agricultural production methods, rapeseed is facing more and more threats from pests and diseases. Clubroot, as one of the most destructive diseases in rapeseed production, has a serious impact on the yield and quality of rapeseed.

[0003] Traditional compound bacterial agents take a long time to exert obvious control effects after application. When clubroot breaks out rapidly, the disease cannot be controlled promptly and effectively, causing serious damage to rapeseed during this period, affecting yield and quality. Summary of the invention

[0004] In view of the deficiencies in the prior art, the present invention provides a composite bacterial agent for preventing and controlling rapeseed clubroot, which solves the problem that traditional composite bacterial agents take a long time to exert obvious prevention and control effects after application, and cannot timely and effectively control the disease in the event of a rapid outbreak of clubroot, causing the rapeseed to be seriously damaged during this period, affecting yield and quality.

[0005] To achieve the above objectives, the present invention is implemented through the following technical scheme: a composite bacterial agent for preventing and controlling rapeseed clubroot disease, comprising the following raw materials in parts by weight: 10-12 parts of acid-resistant Bacillus, 12-15 parts of fluorescing Pseudomonas PF-5, 8-10 parts of gelatinous Bacillus, 5-7 parts of halophilic Bacillus, 8-10 parts of amyloliquefaciens, 2-15 parts of dark green Trichoderma ReTv21, 6-8 parts of round brown nitrogen-fixing bacteria, 10-12 parts of chitosan-γ-polyglutamic acid microspheres, 12-15 parts of diatomaceous earth, 8-12 parts of humic acid, and 2-4 parts of seaweed polysaccharides.

[0006] Preferably, the ratio of the viable counts of the acid-resistant Bacillus, Trichoderma aureum ReTv2 and Pseudomonas fluorescens PF-5 is 1:2.5-3.5:1.8-2.2, and the total viable count is ≥5.0×10 10 CFU / g.

[0007] Preferably, the mass ratio of the chitosan-γ-polyglutamic acid microspheres to diatomaceous earth is 0.6-0.8:1.

[0008] The method for preparing a composite bacterial agent for preventing and treating rape clubroot disease comprises the following steps:

[0009] S1. Strain propagation: Acid-resistant Bacillus, Pseudomonas fluorescens PF-5, Bacillus jelly-like, Bacillus halophilus, and Bacillus amyloliquefaciens were inoculated into liquid culture medium by weight, and the cells were collected by centrifugation after fermentation. Dark green Trichoderma ReTv2 was inoculated into PDB culture medium by weight, and a spore suspension was obtained by filtering after shaking culture. The round brown nitrogen-fixing bacteria were cultured in nitrogen-free culture medium by weight;

[0010] S2, carrier treatment: taking diatomaceous earth, humic acid, and chitosan-γ-polyglutamic acid microspheres by weight, crushing the diatomaceous earth, mixing it with the humic acid, and then calcining it, and then mixing it with the chitosan-γ-polyglutamic acid microspheres after cooling to obtain a carrier;

[0011] S3, microbial agent molding: adding the bacterial body, spore suspension, cultured round brown nitrogen-fixing bacteria and carrier to seaweed polysaccharide and mixing, granulating in a fluidized bed to obtain microbial agent granules;

[0012] S4. Drying and packaging: After the inoculum granules are dried under low temperature vacuum, they are sealed and packaged using inert gas to complete the preparation.

[0013] Preferably, the fermentation temperature in the SI is 30-37°C, the pH is 6.5-7.5, the fermentation time is 48-72 hours, the culture temperature is 25-28°C, the shaking speed is 150rpm, the culture time is 5-7 days, and the spore concentration of the spore suspension is ≥1×10 8 CFU / mL.

[0014] Preferably, the particle size of the diatomaceous earth in S2 is 200-300 mesh, the ratio of diatomaceous earth to humic acid is 2.5-3.5:0.5-1.5, the calcination temperature is 120-150° C., and the time is 2-3 hours.

[0015] Preferably, the water content of the mixture in S3 is ≤8%, the granulation temperature is 35-40° C., and the particle size of the bacterial agent particles is 0.5-1.5 mm.

[0016] Preferably, the temperature of the low-temperature vacuum drying in S4 is 40-45° C., and the water content is ≤5%.

[0017] The present invention provides a composite bacterial agent for preventing and treating rape clubroot disease. It has the following beneficial effects:

[0018] 1. The present invention uses acid-resistant Bacillus to seize the living space of root-knot bacteria; Pseudomonas fluorescens PF-5 directly attacks the bacteria and stimulates the rapeseed's own defense system; Bacillus amyloliquefaciens releases a variety of antibacterial substances; Dark green Trichoderma ReTv2 quickly destroys the structure of root-knot bacteria by heavy parasitism and secretion of extracellular enzymes. At the same time, chitosan-γ-polyglutamic acid microspheres bring microorganisms to the rhizosphere of rapeseed and can also assist in antibacterial treatment; seaweed polysaccharides quickly enhance rapeseed's stress resistance and help rapeseed resist diseases, so that it can respond quickly, control the root-knot disease in time, effectively ensure rapeseed growth, and improve yield and quality.

[0019] 2. The present invention uses acid-resistant Bacillus to adapt to acidic soil and inhibit pathogens, Pseudomonas fluorescens PF-5 to produce antibiotics, rob iron sources and induce plant resistance, and Trichoderma viride ReTv2 heavily parasitizes root-root pathogens. Each strain inhibits the growth and reproduction of root-root pathogens in all directions based on different mechanisms, thereby improving the prevention and control effect of rapeseed root-root disease and effectively reducing the incidence rate and disease index.

[0020] 3. The present invention provides a nitrogen source for rapeseed by fixing nitrogen in the air through round brown nitrogen-fixing bacteria, and gelatinous Bacillus dissolves phosphorus, potassium and silicon to improve soil nutrient utilization rate, and Bacillus megaterium decomposes organic matter to produce plant growth hormone, which jointly promotes the development of rapeseed root system and plant growth, makes rapeseed grow strong, enhances its own stress resistance, and improves rapeseed yield and quality while resisting clubroot disease.

[0021] 4. The present invention enhances the tolerance of the bacterial agent to adverse environments such as soil salinity fluctuations by using halophilic Bacillus, and chitosan-γ-polyglutamic acid microspheres, humic acid and diatomaceous earth improve the soil structure and physical and chemical properties, creating a good microenvironment for the survival of microorganisms, so that the composite bacterial agent can adapt to different soil and climatic conditions, play a stable role in a variety of environments, and expand the scope of application.

[0022] 5. Most of the microorganisms in the composite microbial agent of the present invention are beneficial bacteria selected from the natural environment, which are friendly to rapeseed, soil and the environment, do not produce residual pollution like chemical pesticides, reduce damage to the ecological environment and the impact on non-target organisms, conform to the development concept of green agriculture and organic agriculture, and are conducive to the sustainable development of agriculture. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 The present invention is a flow chart of the method for preparing the composite bacterial agent for preventing and controlling rape clubroot. DETAILED DESCRIPTION

[0024] The technical solution of the present invention will be described clearly and completely below in conjunction with the accompanying drawings of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0025] The embodiment of the present invention provides a composite bacterial agent for preventing and treating rape clubroot, comprising the following raw materials in parts by weight: 10-12 parts of acid-resistant Bacillus, 12-15 parts of fluorescing Pseudomonas PF-5, 8-10 parts of jelly-like Bacillus, 5-7 parts of halophilic Bacillus, 8-10 parts of amyloliquefaciens, 12-15 parts of dark green Trichoderma ReTv2, 6-8 parts of round brown nitrogen-fixing bacteria, 10-12 parts of chitosan-γ-polyglutamic acid microspheres, 12-15 parts of diatomaceous earth, 8-12 parts of humic acid, and 2-4 parts of seaweed polysaccharide; the ratio of the number of live bacteria of acid-resistant Bacillus, dark green Trichoderma ReTv2 and fluorescing Pseudomonas PF-5 is 1:2.5-3.5:1.8-2.2, and the total number of live bacteria is ≥5.0×10 10 CFU / g; the mass ratio of chitosan-γ-polyglutamic acid microspheres to diatomaceous earth is 0.6-0.8:1.

[0026] Specifically, by adding acid-tolerant Bacillus and utilizing its acid-resistant properties, the growth and reproduction of root-root pathogens can be effectively inhibited in acidic soil environments where rapeseed root-root pathogens are prevalent. Acid-tolerant Bacillus can quickly colonize around the rapeseed root system under acidic conditions, and prevent the infection of root-root pathogens by competing for nutrients and living space. At the same time, it secretes antibacterial substances to further reduce the activity of root-root pathogens, creating a good rhizosphere environment for rapeseed growth.

[0027] By adding Pseudomonas fluorescens PF-5, a variety of antibiotics can be produced, such as phenazines, pyrrolizidine, etc., which have a direct inhibitory effect on root knot pathogens and can destroy the cell structure and physiological function of the pathogen. At the same time, Pseudomonas fluorescens PF-5 can also secrete iron carriers to compete with root knot pathogens for iron, causing the growth of the pathogen to be hindered due to lack of iron source. In addition, it can also induce systemic resistance in rapeseed and enhance its own resistance to root knot disease.

[0028] With the addition of Bacillus gelatinosa, its powerful ability to solubilize phosphorus, potassium and silicon can be brought into play, and it can convert insoluble nutrients such as phosphorus, potassium and silicon in the soil into forms that can be absorbed and utilized by rapeseed, thereby improving soil nutrient utilization rate, promoting rapeseed growth, and enhancing rapeseed's resistance to stress, so that rapeseed has more sufficient nutrients to support its growth and defense mechanism when facing the threat of clubroot disease.

[0029] By adding halophilic Bacillus, due to its strong salt resistance and tolerance to adverse environments, it can protect other microorganisms in the composite bacterial agent when the soil environment changes (such as salt fluctuations, drought, etc.), maintain the activity and stability of the entire bacterial community, and to a certain extent regulate the soil microecological environment, creating environmental conditions that are not conducive to the survival of root knot bacteria.

[0030] By adding dark green Trichoderma ReTv2, it acts on the root knot fungus in a heavy parasitic way. Its hyphae can entangle and penetrate the mycelium of the root knot fungus, absorb the nutrients of the pathogen, and cause the death of the pathogen. At the same time, dark green Trichoderma ReTv2 can also secrete a variety of extracellular enzymes such as chitinase and β-1,3-glucanase, degrade the cell wall of the root knot fungus, and inhibit its growth and reproduction. In addition, the antibiotics and volatile substances it produces can also inhibit the root knot fungus.

[0031] With the addition of brown nitrogen-fixing bacteria, which have the ability to fix nitrogen, they can convert nitrogen in the air into ammonia nitrogen, provide additional nitrogen nutrition for rapeseed, and reduce rapeseed's dependence on chemical nitrogen fertilizers. Adequate nitrogen supply helps the growth and development of rapeseed plants, making them stronger and enhancing their resistance to clubroot.

[0032] By adding chitosan-γ-polyglutamic acid microspheres, on the one hand, as an excellent microbial carrier, it has good biocompatibility and adsorption, can firmly adsorb various microorganisms in the composite bacterial agent, provide a protective barrier for microorganisms, reduce the damage of the external environment to microorganisms, and improve the survival rate and colonization ability of microorganisms in the soil. On the other hand, chitosan and γ-polyglutamic acid themselves have certain antibacterial effects and can assist in inhibiting root knot bacteria. In addition, the strong moisture retention of γ-polyglutamic acid helps maintain soil moisture and create suitable moisture conditions for the growth and activity of microorganisms.

[0033] Through the addition of diatomaceous earth, which has a large specific surface area and good adsorption properties, it can absorb moisture and nutrients in the soil, providing a relatively stable nutrition and moisture environment for microorganisms and rapeseed roots. At the same time, diatomaceous earth, as a carrier, helps to evenly disperse the various components in the composite bacterial agent, and its physical structure can improve the air permeability and water permeability of the soil, which is beneficial to the growth of microorganisms and the respiration of rapeseed roots.

[0034] By adding humic acid, it can improve soil structure, increase the stability of soil aggregates, and improve the soil's ability to retain water and fertilizer. It can also provide rich carbon sources and energy for microorganisms in the soil, promote the growth and reproduction of microorganisms, and optimize the soil microbial community structure. In addition, humic acid has a certain buffering capacity and can adjust the soil pH, creating a more suitable soil environment for rapeseed growth and the activity of microorganisms in the compound bacterial agent.

[0035] Through the addition of seaweed polysaccharides, seaweed polysaccharides contain a variety of biologically active ingredients, which can enhance the stress resistance of rapeseed and improve its resistance to clubroot. It can regulate the physiological metabolic process of rapeseed plants, promote the division and elongation of plant cells, and enhance the growth potential of rapeseed. At the same time, seaweed polysaccharides also have a certain antibacterial effect and can cooperate with other ingredients to inhibit clubroot bacteria.

[0036] Through the coordination of various raw materials, a microbial ecosystem and soil improvement system with synergistic functions and mutual promotion is constructed. Through competition, antagonism, symbiosis and other relationships, various microorganisms jointly inhibit the growth and reproduction of root-root pathogens; carriers and soil improvement components provide good environmental conditions for the survival and activities of microorganisms, while promoting the growth and development of rapeseed, thus achieving efficient and rapid prevention and control of rapeseed root-root disease, improving rapeseed's disease resistance and yield quality, and solving the problem that traditional compound bacterial agents take a long time from application to exert obvious prevention and control effects. In the case of a rapid outbreak of root-root disease, the disease cannot be controlled in a timely and effective manner, resulting in rapeseed being severely damaged during this period, affecting yield and quality.

[0037] The ratio of viable bacteria of acid-resistant Bacillus, dark green Trichoderma ReTv2 and Pseudomonas fluorescens PF-5 was 1:2.5-3.5:1.8-2.2, and the total viable bacteria count was ≥5.0×10 10 CFU / g ensures that these three key microorganisms achieve synergistic effects in quantity and proportion. The appropriate ratio of live bacteria enables acid-resistant Bacillus to effectively colonize in acidic soil, creating a suitable living environment for dark green Trichoderma ReTv2 and fluorescing Pseudomonas PF-5. Dark green Trichoderma ReTv2, with its heavy parasitic and enzyme-producing antibacterial properties, synergizes with the antibiotics and iron carriers produced by Pseudomonas PF-5 to form a multi-faceted inhibition of root knot pathogens. A sufficiently high total live bacteria count ensures that when root knot disease occurs, there are sufficient numbers of effective microorganisms to quickly take effect and quickly control the development of the disease.

[0038] The performance of the carrier system is optimized by setting the mass ratio of chitosan-γ-polyglutamate microspheres to diatomaceous earth to 0.6-0.8:1. The good adsorption and protection of chitosan-γ-polyglutamate microspheres are combined with the large specific surface area of ​​diatomaceous earth and the function of improving the physical properties of soil. This can not only give full play to the protection and adsorption effect of chitosan-γ-polyglutamate microspheres on microorganisms, but also optimize the soil environment with the help of diatomaceous earth, promote the dispersion and survival of microorganisms in the soil, and improve the stability and effectiveness of the composite bacterial agent.

[0039] Please refer to the attached Figure 1 A method for preparing a composite bacterial agent for preventing and treating rape clubroot disease comprises the following steps:

[0040] S1. Strain propagation: Acid-resistant Bacillus, Pseudomonas fluorescens PF-5, Bacillus jelly, Bacillus halophilus, and Bacillus amyloliquefaciens were inoculated into liquid culture medium by weight, and the cells were collected by centrifugation after fermentation. Dark green Trichoderma ReTv2 was inoculated into PDB culture medium by weight, and a spore suspension was obtained by filtration after shaking culture. The round brown nitrogen-fixing bacteria were cultured in nitrogen-free culture medium by weight. The fermentation temperature in SI was 30-37°C, the pH was 6.5-7.5, the fermentation time was 48-72 hours, the culture temperature was 25-28°C, the shaking speed was 150rpm, the culture time was 5-7 days, and the spore concentration of the spore suspension was ≥1×10 8 CFU / mL.

[0041] Specifically, acid-fast Bacillus, fluorescing Pseudomonas PF-5, gelatinous Bacillus, halophilic Bacillus, and Bacillus amyloliquefaciens are inoculated into a liquid culture medium by weight, the cells are collected by centrifugation after fermentation, dark green Trichoderma ReTv2 is inoculated into a PDB culture medium by weight, a spore suspension is obtained by filtration after shaking culture, and round brown nitrogen-fixing bacteria are cultured in a nitrogen-free culture medium by weight, thereby providing a suitable growth environment for different microorganisms. The specific liquid culture medium meets the requirements of acid-fast Bacillus and other bacteria for nutrients. Under the conditions of 30-37°C and pH 6.5-7.5, this temperature and pH range are close to the optimal growth conditions for these bacteria, which is conducive to their rapid reproduction and large-scale proliferation within 48-72 hours. High-concentration live bacteria can be obtained by centrifuging the cells, which provides sufficient effective ingredients for the subsequent preparation of the composite bacterial agent.

[0042] PDB medium is suitable for the growth of dark green Trichoderma ReTv2. The culture temperature of 25-28℃ and the shaking speed of 150rpm can not only ensure sufficient oxygen supply, but also make Trichoderma uniformly distributed in the culture medium, promote its growth and spore production. After 5-7 days of culture, the spore concentration obtained by filtration is ≥1×10 8 CFU / mL of spore suspension ensures that dark green Trichoderma ReTv2 has sufficient quantity and activity in the composite bacterial agent.

[0043] The nitrogen-free culture medium is specifically used for the cultivation of round-brown nitrogen-fixing bacteria, because round-brown nitrogen-fixing bacteria has the ability to fix nitrogen. In a nitrogen-free environment, it can use nitrogen in the air to synthesize the nitrogen-containing substances it needs, thereby achieving growth and reproduction, and providing the composite bacterial agent with microorganisms with nitrogen-fixing function. Such a strain expansion step specifically cultivates various functional microorganisms, ensures their activity and quantity in subsequent composite bacterial agents, and lays the foundation for the effective prevention and control of rapeseed root knot disease.

[0044] S2, carrier treatment: diatomaceous earth, humic acid, chitosan-γ-polyglutamic acid microspheres are taken by weight, the diatomaceous earth is crushed and mixed with humic acid, and then calcined, and then mixed with chitosan-γ-polyglutamic acid microspheres after cooling to obtain a carrier; the particle size of the crushed diatomaceous earth in S2 is 200-300 mesh, and the ratio of the diatomaceous earth to the humic acid is 2.5-3.5:0.5-1.5, the calcination temperature is 120-150° C., and the time is 2-3 hours.

[0045] Specifically, diatomaceous earth, humic acid and chitosan-γ-polyglutamic acid microspheres are taken by weight, the diatomaceous earth is crushed, mixed with humic acid and then calcined, and then mixed with chitosan-γ-polyglutamic acid microspheres after cooling to obtain a carrier, thereby crushing the diatomaceous earth to 200-300 meshes, greatly increasing the specific surface area of ​​the diatomaceous earth and making it have stronger adsorption performance, and mixing with humic acid in a ratio of 2.5-3.5:0.5-1.5. Humic acid is rich in various organic functional groups and can interact with diatomaceous earth to further improve the physical and chemical properties of the carrier. In the final product, the total weight ratio of diatomaceous earth to humic acid is 12-15:8-12.

[0046] Calcination at 120-150℃ for 2-3 hours can remove impurities in diatomaceous earth and humic acid, stabilize their chemical structure, and enhance the stability of the carrier. At the same time, high-temperature calcination can also cause a certain chemical reaction between the two to form a surface structure that is more conducive to the attachment and growth of microorganisms.

[0047] After cooling, it is mixed with chitosan-γ-polyglutamic acid microspheres. The chitosan-γ-polyglutamic acid microspheres themselves have good biocompatibility and adsorption and protection effects on microorganisms. Combined with the calcined diatomaceous earth and humic acid mixture, an excellent composite carrier is constructed, which can not only provide a stable attachment site for microorganisms, but also protect microorganisms from the influence of adverse external environment, improve the survival rate and activity of microorganisms in the soil, and thus enhance the control effect of the composite bacterial agent.

[0048] S3, bacterial agent molding: the bacterial body, spore suspension and cultured brown nitrogen-fixing bacteria and carrier are added to seaweed polysaccharide and mixed, and granulated in a fluidized bed to obtain bacterial agent granules; the water content of the mixture in S3 is ≤8%, the granulation temperature is 35-40°C, and the particle size of the bacterial agent granules is 0.5-1.5mm.

[0049] Specifically, the bacterial bodies, spore suspension, cultured brown nitrogen-fixing bacteria and a carrier are added with seaweed polysaccharide, mixed, and granulated in a fluidized bed to obtain bacterial agent granules. The seaweed polysaccharide not only has a certain adhesiveness, but also contains a variety of biologically active ingredients. As a binder, it can tightly combine the bacterial bodies, spore suspension, brown nitrogen-fixing bacteria and the carrier together, and under the condition of a water content of ≤8%, it is ensured that the various components are evenly distributed in the granulation process to form a stable structure.

[0050] The fluidized bed granulation is carried out at a temperature of 35-40°C. This temperature range can ensure the bonding properties of seaweed polysaccharides without causing significant damage to the activity of microorganisms. By controlling the granulation conditions, the particle size of the microbial agent particles can reach 0.5-1.5 mm. Such a particle size is conducive to the dispersion and spread of the microbial agent in the soil and is convenient for application. At the same time, it can also ensure that the microbial agent has appropriate strength and is not easy to break, thereby improving the practicality and storage stability of the microbial agent. The final microbial agent particles integrate various effective ingredients together, so that they can work synergistically in subsequent applications and improve the prevention and control effect of rapeseed root knot disease.

[0051] S4, drying and packaging: After the inoculum granules are dried at low temperature and vacuum, they are sealed and packaged using inert gas to complete the preparation; the temperature of low temperature and vacuum drying in S4 is 40-45°C, and the water content is ≤5%.

[0052] Specifically, the inoculum granules are vacuum dried at low temperature and then sealed and packaged with inert gas. The low temperature vacuum drying is carried out at 40-45°C. This can quickly remove moisture from the inoculum granules while minimizing the impact on the activity of the microorganisms. The moisture content is made ≤5%. A lower moisture content can inhibit the metabolic activity of the microorganisms, reduce the risk of inactivation of the microorganisms due to excessive moisture, and extend the shelf life of the inoculum.

[0053] Use inert gas for sealed packaging. Inert gas with stable chemical properties, such as nitrogen, argon, etc., can effectively isolate oxygen and moisture in the air, prevent microorganisms from being oxidized, and avoid the deterioration of the agent due to the absorption of moisture in the air. It provides a stable storage environment for the compound agent, ensuring that the microorganisms in the agent can maintain high activity during storage and transportation. When the user uses it, the agent can play its due role in preventing and treating rapeseed root knot disease.

[0054] The following is further introduced in conjunction with specific embodiments:

[0055] Embodiment 1:

[0056] The composite bacterial agent for preventing and treating rapeseed clubroot disease comprises the following raw materials in parts by weight: 12 parts of acid-resistant Bacillus, 15 parts of fluorescing Pseudomonas PF-5, 10 parts of gelatinous Bacillus, 7 parts of halophilic Bacillus, 10 parts of Bacillus amyloliquefaciens, 15 parts of dark green Trichoderma ReTv2, 8 parts of round brown nitrogen-fixing bacteria, 12 parts of chitosan-γ-polyglutamic acid microspheres, 15 parts of diatomaceous earth, 12 parts of humic acid, and 4 parts of seaweed polysaccharide.

[0057] The ratio of viable bacteria counts of acid-resistant Bacillus, dark green Trichoderma ReTv2 and Pseudomonas fluorescens PF-5 was 1:3:2, and the total viable bacteria count was ≥5.0×10 10 CFU / g.

[0058] The mass ratio of chitosan-γ-polyglutamic acid microspheres to diatomaceous earth is 0.7:1.

[0059] The method for preparing a composite bacterial agent for preventing and treating rape clubroot disease comprises the following steps:

[0060] S1. Strain propagation: Acid-resistant Bacillus, Pseudomonas fluorescens PF-5, Bacillus jelly-like, Bacillus halophilus, and Bacillus amyloliquefaciens were inoculated into liquid culture medium by weight, and the cells were collected by centrifugation after fermentation. Dark green Trichoderma ReTv2 was inoculated into PDB culture medium by weight, and a spore suspension was obtained by filtering after shaking culture. The round brown nitrogen-fixing bacteria were cultured in nitrogen-free culture medium by weight;

[0061] S2, carrier treatment: taking diatomaceous earth, humic acid, and chitosan-γ-polyglutamic acid microspheres by weight, crushing the diatomaceous earth, mixing it with the humic acid, and then calcining it, and then mixing it with the chitosan-γ-polyglutamic acid microspheres after cooling to obtain a carrier;

[0062] S3, microbial agent molding: adding the bacterial body, spore suspension, cultured round brown nitrogen-fixing bacteria and carrier to seaweed polysaccharide and mixing, granulating in a fluidized bed to obtain microbial agent granules;

[0063] S4. Drying and packaging: After the inoculum granules are dried under low temperature vacuum, they are sealed and packaged using inert gas to complete the preparation.

[0064] The fermentation temperature in SI was 33.5°C, pH 7, fermentation time 60 hours, culture temperature 26.5°C, shaking speed 150 rpm, culture time 6 days, and spore concentration of spore suspension ≥ 1 × 10 8 CFU / mL.

[0065] The particle size of the diatomaceous earth in S2 is 250 mesh, and the ratio of diatomaceous earth to humic acid is 3:1. The calcination temperature is 135° C. and the time is 2.5 hours.

[0066] The mixed water content in S3 is ≤8%, the granulation temperature is 37°C, and the particle size of the bacterial agent granules is 1 mm.

[0067] The temperature of low temperature vacuum drying in S4 is 42.5°C and the water content is ≤5%.

[0068] Embodiment 2:

[0069] The difference between this embodiment and the above-mentioned embodiment 1 is that:

[0070] The composite bacterial agent for preventing and treating rape clubroot disease is characterized in that it comprises the following raw materials in parts by weight: 10 parts of acid-resistant Bacillus, 12 parts of fluorescing Pseudomonas PF-5, 8 parts of gelatinous Bacillus, 5 parts of halophilic Bacillus, 8 parts of Bacillus amyloliquefaciens, 12 parts of dark green Trichoderma ReTv2, 6 parts of round brown nitrogen-fixing bacteria, 10 parts of chitosan-γ-polyglutamic acid microspheres, 12 parts of diatomaceous earth, 8 parts of humic acid, and 2 parts of seaweed polysaccharide.

[0071] Embodiment 3:

[0072] The difference between this embodiment and the above-mentioned embodiment 1 is that:

[0073] The composite bacterial agent for preventing and treating rape clubroot disease is characterized in that it comprises the following raw materials in parts by weight: 11 parts of acid-resistant Bacillus, 13.5 parts of fluorescing Pseudomonas PF-5, 9 parts of gelatinous Bacillus, 6 parts of halophilic Bacillus, 9 parts of Bacillus amyloliquefaciens, 13.5 parts of dark green Trichoderma ReTv2, 7 parts of round brown nitrogen-fixing bacteria, 11 parts of chitosan-γ-polyglutamic acid microspheres, 12.5 parts of diatomaceous earth, 10 parts of humic acid, and 3 parts of seaweed polysaccharide.

[0074] Table 1:

[0075] contrast Example 1 Example 2 Example 3 Standard value Incidence (%) 10 15 12 30 Root length (cm) 25 23 24 20 Root dry weight (g) 15 13 14 10

[0076] The above table is compared with the traditional composite bacterial agent. It can be seen from Table 1 that different amounts of acid-resistant Bacillus, fluorescing Pseudomonas PF-5, gelatinous Bacillus, halophilic Bacillus, Bacillus amyloliquefaciens, dark green Trichoderma ReTv2, round brown nitrogen-fixing bacteria, chitosan-γ-polyglutamic acid microspheres, diatomaceous earth, humic acid, and seaweed polysaccharides can affect the incidence rate, root length, and root dry weight of the composite bacterial agent. Through the synergistic effect of each component, the overall performance of the composite bacterial agent is optimized, and the efficient prevention and control of rapeseed root root disease is achieved, and the root growth and plant development of rapeseed are promoted. The problem that the traditional composite bacterial agent cannot control the disease in a timely and effective manner, resulting in serious damage to rapeseed during this period, affecting the yield and quality, is solved, the yield and quality of rapeseed are guaranteed, and the development of green agriculture is promoted.

[0077] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A composite bacterial agent for preventing and treating rape clubroot, characterized in that: The invention comprises the following raw materials in parts by weight: 10-12 parts of acid-resistant Bacillus, 12-15 parts of fluorescing Pseudomonas PF-5, 8-10 parts of gelatinous Bacillus, 5-7 parts of halophilic Bacillus, 8-10 parts of amyloliquefaciens, 12-15 parts of dark green Trichoderma ReTv2, 6-8 parts of round brown nitrogen-fixing bacteria, 10-12 parts of chitosan-γ-polyglutamic acid microspheres, 12-15 parts of diatomaceous earth, 8-12 parts of humic acid and 2-4 parts of seaweed polysaccharide.

2. The composite bacterial agent for preventing and treating rape clubroot according to claim 1, characterized in that: The ratio of the viable bacteria count of the acid-resistant Bacillus, dark green Trichoderma ReTv2 and Pseudomonas fluorescens PF-5 is 1:2.5-3.5:1.8-2.2, and the total viable bacteria count is ≥5.0×10 10 CFU / g.

3. The composite bacterial agent for preventing and treating rape clubroot according to claim 1, characterized in that: The mass ratio of the chitosan-γ-polyglutamic acid microspheres to diatomaceous earth is 0.6-0.8:

1.

4. A method for preparing a composite bacterial agent for preventing and treating rape clubroot, characterized in that: The composite bacterial agent for preventing and treating rape clubroot disease as claimed in any one of claims 1 to 3 comprises the following steps: S1. Strain propagation: Acid-resistant Bacillus, Pseudomonas fluorescens PF-5, Bacillus jelly-like, Bacillus halophilus, and Bacillus amyloliquefaciens were inoculated into liquid culture medium by weight, and the cells were collected by centrifugation after fermentation. Dark green Trichoderma ReTv2 was inoculated into PDB culture medium by weight, and a spore suspension was obtained by filtering after shaking culture. The round brown nitrogen-fixing bacteria were cultured in nitrogen-free culture medium by weight; S2, carrier treatment: taking diatomaceous earth, humic acid, and chitosan-γ-polyglutamic acid microspheres by weight, crushing the diatomaceous earth, mixing it with the humic acid, and then calcining it, and then mixing it with the chitosan-γ-polyglutamic acid microspheres after cooling to obtain a carrier; S3, microbial agent molding: adding the bacterial body, spore suspension, cultured round brown nitrogen-fixing bacteria and carrier to seaweed polysaccharide and mixing, granulating in a fluidized bed to obtain microbial agent granules; S4. Drying and packaging: After the inoculum granules are dried under low temperature vacuum, they are sealed and packaged using inert gas to complete the preparation.

5. The method for preparing the composite bacterial agent for preventing and treating rape clubroot according to claim 4, characterized in that: The fermentation temperature in the SI is 30-37°C, the pH is 6.5-7.5, the fermentation time is 48-72 hours, the culture temperature is 25-28°C, the shaking speed is 150rpm, the culture time is 5-7 days, and the spore concentration of the spore suspension is ≥1×10 8 CFU / mL.

6. The method for preparing the composite bacterial agent for preventing and treating rape clubroot according to claim 4, characterized in that: The particle size of the diatomaceous earth in S2 is 200-300 meshes, the ratio of diatomaceous earth to humic acid is 2.5-3.5:0.5-1.5, the calcination temperature is 120-150° C., and the calcination time is 2-3 hours.

7. The method for preparing the composite bacterial agent for preventing and treating rape clubroot according to claim 4, characterized in that: The water content of the mixture in S3 is ≤8%, the granulation temperature is 35-40° C., and the particle size of the bacterial agent particles is 0.5-1.5 mm.

8. The method for preparing the composite bacterial agent for preventing and treating rape clubroot according to claim 4, characterized in that: The temperature of the low temperature vacuum drying in S4 is 40-45° C., and the water content is ≤5%.

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