Bacillus amyloliquefaciens strain for preventing and treating rice blast as well as preparation method and application thereof

Abstract

The invention discloses a bacillus amyloliquefaciens strain for preventing and treating rice blast and a preparation method and application thereof.The bacillus amyloliquefaciens strain for preventing and treating rice blast is classified and named as Bacillus amyloliquefaciens H77 and is preserved in Institute of Microbiology, Guangdong Academy of Sciences, Guangdong Province, the preservation unit address is the fifth floor, No. 59, No. 100 Courtyard, Xianlie Middle Road, Guangzhou City, and the preservation number is CGMCC NO. The preservation date is December 9, 2024; the preservation number of the strain is GDMCC (China General Microbiological Culture Collection Center According to the invention, the control effect of the rice blast can be improved, the strain is safe and environment-friendly, the influence of chemical pesticide use on the environment is reduced, the screened strain H77 has a remarkable inhibition effect on the rice blast bacteria GUY11, the inhibition rate reaches 82.19%, and control effect experiments show that the strain H77 can also effectively reduce the morbidity and disease index of the rice blast.

Description

Technical Field

[0001] The present invention relates to the technical field of agricultural microorganisms, and specifically relates to a Bacillus amyloliquefaciens strain for controlling rice blast, and its preparation method and application. Background Art

[0002] Rice blast is one of the main diseases in rice production, caused by Magnaporthe oryzae, which seriously affects the yield and quality of rice. During the process of rice cultivation, the control of rice blast has always been an important issue in agricultural production.

[0003] Traditional methods for controlling rice blast mainly rely on chemical pesticides. Although they can effectively control the disease in the short term, long-term use of chemical pesticides will lead to problems such as environmental pollution, enhanced pathogen resistance, and harm to non-target organisms. Therefore, it is particularly important to develop environmentally friendly and sustainable control methods. In recent years, biological control, as an environmentally friendly control method, has received extensive attention due to its advantages such as high efficiency, safety, and pollution-free.

[0004] In the field of biological control, using antagonistic microorganisms to control plant diseases is an effective strategy. Antagonistic microorganisms can inhibit the growth and reproduction of pathogens by producing antibacterial substances, competing for nutrients and space, and inducing plant defense responses. However, current research and application of antagonistic microorganisms are still relatively limited. Especially for the biological control of rice blast, new antagonistic microorganism resources need to be further explored and utilized.

[0005] Although some studies have reported the application of antagonistic microorganisms in the control of rice blast, most of the studies are still at the laboratory stage and lack systematic field application research. In addition, existing antagonistic microorganism strains may face problems such as poor environmental adaptability and insufficient stability in actual applications, which limit their wide application in agricultural production.

[0006] Currently, there is a lack of a Bacillus amyloliquefaciens strain for controlling rice blast with high control efficiency, and its preparation method and application. Summary of the Invention

[0007] The purpose of the present invention is to provide a Bacillus amyloliquefaciens strain for controlling rice blast with high control efficiency, and its preparation method and application.

[0008] To solve the problems of the existing technology, the present invention provides the following technical solutions: In the first aspect, the present application provides a Bacillus amyloliquefaciens strain for controlling rice blast;

[0009] In the second aspect, the present application provides a bacterial agent of Bacillus amyloliquefaciens for controlling rice blast;

[0010] In a third aspect, the present application provides a method for preparing a spore suspension of a Bacillus amyloliquefaciens strain for controlling rice blast;

[0011] In a fourth aspect, the present application provides a use of a Bacillus amyloliquefaciens strain for controlling rice blast or a Bacillus amyloliquefaciens agent for controlling rice blast in the preparation of a preparation for controlling rice blast.

[0012] The first aspect of the present application provides a Bacillus amyloliquefaciens strain for controlling rice blast. The classification name of the Bacillus amyloliquefaciens strain for controlling rice blast is Bacillus amyloliquefaciens H77, which is deposited in the Institute of Microbiology, Guangdong Academy of Sciences, Guangdong Microbiological Culture Collection Center. The address of the depository is 5th Floor, Building 59, No. 100 Xianlie Middle Road, Guangzhou. The deposit date is December 9, 2024; the deposit number is GDMCC No. 65596.

[0013] Furthermore, the 16s rDNA sequence of the rice blast control Bacillus amyloliquefaciens strain is the nucleotide sequence shown in SEQ ID No.1.

[0014] A second aspect of the present application provides a rice blast control Bacillus amyloliquefaciens agent prepared by a rice blast control Bacillus amyloliquefaciens strain.

[0015] Furthermore, the active ingredient is at least one of the following (a), (b), and (c):

[0016] (a) a fermentation culture of a rice blast controlling Bacillus amyloliquefaciens strain;

[0017] (b) obtaining a spore suspension of the rice blast control Bacillus amyloliquefaciens strain;

[0018] (c) Ultrasonic lysis precipitation of the obtained rice blast control Bacillus amyloliquefaciens strain cells.

[0019] The third aspect of the present application provides a method for preparing a Bacillus amyloliquefaciens agent for controlling rice blast, comprising the following steps: picking an activated single colony of Bacillus amyloliquefaciens H77 with an inoculation loop and inoculating it on 200 mL of NB culture medium, and culturing it in a shaker at 33° C. and 180 rpm for 3 days for use.

[0020] Furthermore, the NB medium consists of 10 g of peptone, 3 g of beef extract powder and 5 g of sodium chloride.

[0021] A fourth aspect of the present application provides a use of a Bacillus amyloliquefaciens strain for controlling rice blast or the Bacillus amyloliquefaciens agent for controlling rice blast according to claim 3 in the preparation of a preparation for controlling rice blast.

[0022] Beneficial effects: The present invention has high control efficiency, is environmentally friendly, and has low cost. Strain H77 has an obvious inhibitory effect on Magnaporthe oryzae GUY11, with an inhibition rate as high as 82.19%, effectively reducing the incidence and disease index of rice blast, and improving the control efficiency.

[0023] Compared with the prior art, the present invention has the following advantages: (1) Environmental friendliness: The biological control method adopted by the present invention avoids the use of chemical pesticides, reduces environmental pollution, and is a more environmentally friendly control strategy.

[0024] (2) Reduction of pathogen drug resistance: Long-term use of chemical pesticides will lead to the enhancement of pathogen drug resistance, while the biological control method of the present invention can reduce this risk because microbial strains inhibit pathogens through multiple mechanisms and are not likely to cause resistance problems. Enhancement of crop health: The treatment with strain H77 can not only inhibit the growth of Magnaporthe oryzae, but also induce plants to produce defense responses, enhancing the overall health and resistance of crops.

[0025] (3) Promotion of ecological balance: The method of the present invention helps to maintain the balance of the farmland ecosystem, enhances the self-regulating ability of the ecosystem by utilizing microbial resources in nature. Cost-effectiveness: Compared with traditional chemical control, the biological control method usually has lower costs because microbial strains can be cultured on a large scale and are easy to apply.

[0026] (4) Application flexibility: The method of the present invention can be combined with existing agricultural management measures, such as crop rotation, planting disease-resistant varieties, etc., to provide a more flexible disease management plan. Improvement of crop yield and quality: By effectively controlling rice blast, the present invention helps to improve the yield and quality of rice and ensure food security. Brief Description of the Drawings

[0027] Figure 1 It is a schematic diagram of the colony of strain H77 of the present invention.

[0028] Figure 2 It is a comparative analysis diagram of the sequencing results of strain H77 of the present invention with the NCBI database.

[0029] Figure 3 It is a diagram of the plate confrontation result of the present invention.

[0030] Figure 4 It is a diagram of the change of the mycelium of Magnaporthe oryzae after being treated with the biocontrol bacteria of the present invention.

[0031] Figure 5 It is a diagram of the effect of the strain of the present invention on the spore germination and appressorium of Magnaporthe oryzae.

[0032] Figure 6 It is a diagram of the effect of the fermentation broth of the strain of the present invention on the incidence of rice blast.

[0033] Figure 7 Effect of the fermentation broth of the strain of the present invention on spore germination. Detailed implementation manners

[0034] In order to make the technical problems to be solved, technical solutions and beneficial effects of the present application clearer and more understandable, the following further details the present application in conjunction with embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0035] In the present application, the term "and / or" describes the association relationship of associated objects and indicates that three relationships may exist. For example, A and / or B may represent: A exists alone, A and B exist simultaneously, and B exists alone. Wherein A and B may be singular or plural. The character " / " generally represents an "or" relationship between the front and rear associated objects.

[0036] In the present application, "at least one" means one or more, and "a plurality" means two or more. "At least one (item)" or its similar expression below refers to any combination of these items, including any combination of single item (item) or plural items (items). For example, "at least one (item) of a, b, or c", or, "at least one (item) of a, b, and c" can all represent: a, b, c, a - b (that is, a and b), a - c, b - c, or a - b - c, where a, b, and c can be single or multiple respectively.

[0037] It should be understood that in various embodiments of the present application, the magnitudes of the serial numbers of the above processes do not mean the sequence of execution. Some or all of the steps can be executed in parallel or sequentially. The execution sequence of each process should be determined according to its function and internal logic, and should not constitute any limitation to the implementation process of the embodiments of the present application.

[0038] The terms used in the embodiments of the present application are only for the purpose of describing specific embodiments and are not intended to limit the present application. The singular forms "a", "the" and "said" used in the embodiments of the present application and the appended claims are also intended to include the plural forms unless the context clearly indicates otherwise.

[0039] The weight of the relevant components mentioned in the specification of the embodiments of the present application not only can refer to the specific content of each component, but also can represent the proportional relationship of the weights between the components. Therefore, as long as the content of the relevant components in the specification of the embodiments of the present application is enlarged or reduced in proportion, it is within the scope disclosed in the specification of the embodiments of the present application. Specifically, the mass described in the specification of the embodiments of the present application can be mass units well known in the chemical industry such as μg, mg, g, kg, etc.

[0040] The terms "first" and "second" are used only for descriptive purposes to distinguish objects such as substances from each other, and should not be construed as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. For example, without departing from the scope of the embodiments of the present application, the first XX may also be referred to as the second XX, and similarly, the second XX may also be referred to as the first XX. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more of such features.

[0041] In the first aspect of the embodiments of the present application, a Bacillus amyloliquefaciens strain for controlling rice blast is provided. The taxonomic name of the Bacillus amyloliquefaciens strain for controlling rice blast is Bacillus amyloliquefaciens H77, which is deposited in the Guangdong Provincial Culture Collection Center of Microorganisms, Institute of Microbiology, Guangdong Academy of Sciences. The address of the depositary institution is the 5th floor, Building 59, No. 100 Yard, Xianlie Middle Road, Guangzhou. The deposit date is December 9, 2024; the deposit number is GDMCC No. 65596.

[0042] In some embodiments, the 16S rDNA sequence of the Bacillus amyloliquefaciens strain for controlling rice blast is the nucleotide sequence shown in SEQ ID No. 1.

[0043] SEQ ID No. 1:

[0044] GCTTGCTACAGATAGACATGATAGTCGAGCGGACAGATGGGAGCTTGCTCCCTGATGTTAGCGGCGGA

[0045] CGGGTGAGTAACACGTGGGTAACCTGCCTGTAAGACTGGGATAACTCCGGGAAACCGGGGCTAATAC

[0046] CGGATGGTTGTTTGAACCGCATGGTTCAGACATAAAAGGTGGCTTCGGCTACCACTTACAGATGGACC

[0047] CGCGGCGCATTAGCTAGTTGGTGAGGTAACGGCTCACCAAGGCGACGATGCGTAGCCGACCTGAGAG

[0048] GGTGATCGGCCACACTGGGACTGAGACACGGCCCAGACTCCTACGGGAGGCAGCAGTAGGGAATCT

[0049] TCCGCAATGGACGAAAGTCTGACGGAGCAACGCCGCGTGAGTGATGAAGGTTTTCGGATCGTAAAGC

[0050] TCTGTTGTTAGGGAAGAACAAGTGCCGTTCAAATAGGGCGGCACCTTGACGGTACCTAACCAGAAAG

[0051] CCACGGCTAACTACGTGCCAGCAGCCGCGGTAATACGTAGGTGGCAAGCGTTGTCCGGAATTATTGGG

[0052] CGTAAAGGGCTCGCAGGCGGTTTCTTAAGTCTGATGTGAAAGCCCCCGGCTCAACCGGGGAGGGTCA

[0053] TTGGAAACTGGGGAACTTGAGTGCAGAAGAGGAGAGTGGAATTCCACGTGTAGCGGTGAAATGCGT

[0054] AGAGATGTGGAGGAACACCAGTGGCGAAGGCGACTCTCTGGTCTGTAACTGACGCTGAGGAGCGAA

[0055] AGCGTGGGGAGCGAACAGGATTAGATACCCTGGTAGTCCACGCCGTAAACGATGAGTGCTAAGTGTT

[0056] AGGGGGTTTCCGCCCCTTAGTGCTGCAGCTAACGCATTAAGCACTCCGCCTGGGGAGTACGGTCGCA

[0057] AGACTGAAACTCAAAGGAATTGACGGGGGCCCGCACAAGCGGTGGAGCATGTGGTTTA

[0058] In the second aspect of the embodiments of the present application, a bacillus amyloliquefaciens agent for preventing and controlling rice blast, which is prepared from a bacillus amyloliquefaciens strain for preventing and controlling rice blast, is provided.

[0059] In some embodiments, its active ingredient is at least one of the following (a), (b), and (c):

[0060] (a) The fermentation culture of the bacillus amyloliquefaciens strain for preventing and controlling rice blast;

[0061] (b) The spore suspension of the obtained Bacillus amyloliquefaciens strain for controlling rice blast.

[0062] (c) The ultrasonic lysis precipitate of the cells of the obtained Bacillus amyloliquefaciens strain for controlling rice blast.

[0063] The third aspect of the embodiments of the present application provides a preparation method of a Bacillus amyloliquefaciens agent for controlling rice blast, which includes the following steps: Pick a single colony of the activated Bacillus amyloliquefaciens H77 with an inoculation loop and inoculate it on 200 mL of NB medium, and culture it in a shaker at 33 °C and 180 rpm for 3 days for standby. The NB medium consists of 10 g of peptone, 3 g of beef extract powder, and 5 g of sodium chloride.

[0064] The fourth aspect of the embodiments of the present application provides an application of a Bacillus amyloliquefaciens strain for controlling rice blast or a Bacillus amyloliquefaciens agent for controlling rice blast in the preparation of a preparation for controlling rice blast.

[0065] Example 1

[0066] A Bacillus amyloliquefaciens strain for controlling rice blast according to the present invention, the taxonomic name of the Bacillus amyloliquefaciens strain for controlling rice blast is Bacillus amyloliquefaciens H77, which is preserved in the Guangdong Provincial Microbial Culture Collection Center, Institute of Microbiology, Guangdong Academy of Sciences. The address of the preservation unit is the 5th floor of Building 59, No. 100, Xianlie Middle Road, Guangzhou. The preservation date is December 9, 2024; the preservation number is GDMCC No. 65596.

[0067] The 16s rDNA sequence of the Bacillus amyloliquefaciens strain for controlling rice blast is the nucleotide sequence shown in SEQ ID No. 1.

[0068] Example 2

[0069] A Bacillus amyloliquefaciens agent for controlling rice blast prepared from a Bacillus amyloliquefaciens strain according to the present invention, the active ingredient of which is at least one of the following (a), (b), and (c):

[0070] (a) The fermentation culture of the Bacillus amyloliquefaciens strain for controlling rice blast;

[0071] (b) The spore suspension of the obtained Bacillus amyloliquefaciens strain for controlling rice blast;

[0072] (c) The ultrasonic lysis precipitate of the cells of the obtained Bacillus amyloliquefaciens strain for controlling rice blast.

[0073] The preparation method of the Bacillus amyloliquefaciens agent for controlling rice blast according to the present invention includes the following steps:.

[0074] Example 3

[0075] Application of a Bacillus amyloliquefaciens strain for controlling rice blast or a Bacillus amyloliquefaciens agent for controlling rice blast in the preparation of a preparation for controlling rice blast

[0076] Example 4

[0077] 1. Preparation of samples

[0078] Collect the root soil of Huangkenuo from the intercropping system of Huangkenuo and Shanyou 63 in the rice research base of Jianshui, Yunnan. Take 10 g of the mixed soil sample and place it in a triangular flask containing 100 mL of sterile water. Rotate it at 28 °C and 150 r / min for 30 min. After the soil solution stands for 1 h, take 5 mL of the supernatant and add it to 45 mL of sterile water to prepare a 10 －1 concentration dilution solution, and so on, dilute the soil solution to 10 －3 、10 －4 、10 －5 、10 －6 concentrations.

[0079] 2. Preparation of culture medium

[0080] Dissolve NA medium (10 g of peptone, 3 g of beef extract powder, 5 g of sodium chloride, 14 g of agar) in 1000 mL of distilled water, heat until the agar is completely dissolved, dispense the medium into appropriate containers, and sterilize it at 121 °C for 15 min using an autoclave. After sterilization, let the medium cool to about 50 °C, and then pour it into sterile petri dishes for standby.

[0081] 3. Isolation and purification

[0082] Take 500 μL of the soil solution at each concentration and spread it evenly on the culture medium, and culture it at 28 °C for 3 d. Perform three streakings on the grown bacterial colonies until pure culture strains are obtained. Number the obtained pure culture strains in the order of screening. The target strains screened from the intercropped HKN are numbered "H1, H2... H77".

[0083] 4. Screening of rice blast antagonistic bacteria

[0084] Pick the rice blast strain (GUY11) stored on filter paper in the laboratory onto the PDA medium for activation, and keep it for standby after activation. Using the plate confrontation method, use a puncher to take an activated rice blast pathogen cake with a diameter of 1 cm and place it in the center of the PDA medium. Inoculate the purified strain 3 cm away from the pathogen cake, and measure the diameter of the inhibition zone (cross method) after culturing at 28 °C, and calculate the inhibition rate to screen for strains with antagonistic activity.

[0085] Inhibitory rate = (control colony diameter - treated colony diameter) / (control colony diameter - agar disc diameter) × 100% Test Example 1

[0086] 1. Isolation and identification of strains

[0087] H77 growing on NA medium formed milky white and light yellow irregular shapes, and the colonies showed a moist and smooth surface ( Figure 1 ). The size of the 16s rDNA sequence of strain H77 obtained by sequencing was 1450 dp. The sequencing results of strain H77 were compared and analyzed with the NCBI database ( Figure 2 ), and it was inferred that strain H77 belongs to Bacillus amyloliquefaciens.

[0088] 2. Effect of the strain on the growth of Magnaporthe oryzae GUY11

[0089] The results of the plate confrontation showed that the strain had an obvious inhibitory effect on the rice blast pathogen GUY11, and the inhibition rate was 82.19% ( Figure 3 ). In addition, observing the hyphae at the edge of Magnaporthe oryzae under a scanning electron microscope, the hyphae in the control group were tubular, slender and relatively smooth on the surface, with uniform branching to form a complex network structure, showing normal morphological characteristics. However, the hyphae treated with the strain were severely deformed, including shrinkage and abnormal swelling of the pathogen hyphae ( Figure 4 ).

[0090] 3. Effect of the strain on the spore germination and appressorium of Magnaporthe oryzae

[0091] The results showed that the germination rate of Magnaporthe oryzae hyphae in the blank control group was 95.3% and the appressorium formation rate was 89%. After treatment with the strain fermentation broth, the germination rate of Magnaporthe oryzae was 91.3%, and the appressorium formation rate was significantly reduced to 16.7% ( Figure 5 ).

[0092] 4. Determination of the control effect in pot experiments

[0093] The roots of Huangkenuo were irrigated with the fermentation broth of the strain, and sterile water was used as the control. The rice seedlings were planted until the three-leaf and one-heart stage, and 20 ml of the fermentation broth was added for root irrigation respectively. After 24 hours of fermentation broth treatment, the spore suspension of Magnaporthe oryzae was evenly sprayed on the leaves. After inoculating Magnaporthe oryzae for 7 days, the incidence and disease index of rice blast were investigated. The results showed that the fermentation broth of the strain could significantly reduce the incidence of rice blast ( Figure 6 ).

[0094] Test Example 2

[0095] Isolation and identification of antagonistic bacteria against Magnaporthe oryzae in rice

[0096] Collect soil samples from the rhizosphere of intercrop rice, isolate microorganisms by dilution method, and use the plate confrontation culture method to screen out bacteria with good antagonistic effects against GUY11. Compare the strain gene set with the NCBI database, and strain H77 is identified as Bacillus amyloliquefaciens. The inhibition rate of mycelial growth of GUY11 is 82.19% (Table 2). The strain classification and identification and numbers are shown in Table 1:

[0097] Table 1

[0098]

[0099] The inhibition effects of strains on Magnaporthe oryzae are shown in Table 2:

[0100] Table 2

[0101]

[0102] Effect of bacteria on the mycelial morphology of Magnaporthe oryzae

[0103] Using the plate confrontation method, after culturing until an inhibition zone appears on the plate, pick Magnaporthe oryzae near the antagonistic bacterium onto a glass slide, and use the plate inoculated with only Magnaporthe oryzae as a control, and observe the changes in the mycelial morphological structure of Magnaporthe oryzae under a microscope. The results show that the mycelia of Magnaporthe oryzae after treatment with strain H77 show phenomena of adhesion and entanglement.

[0104] Effect of the strain fermentation broth on spore germination

[0105] To clarify the effect of the antagonistic bacterium on the germination of GUY11, observe and compare the spore germination and appressorium formation under different treatments with a microscope, and select 100 spores to calculate the germination rate and appressorium formation rate. The results show that the germination rate of Magnaporthe oryzae mycelia in the blank control group is 95.3% and the appressorium formation rate is 89%. After treatment with the antagonistic bacterium, the germination rate and appressorium formation rate of Magnaporthe oryzae are reduced to 91.3% and 16.7% respectively

[0106] Figure 7 This is the effect diagram of the strain fermentation broth of the present invention on spore germination.

[0107] Control effect of single strain on rice blast

[0108] Irrigate the roots of two rice varieties, Huangkenuo and Lijiangxintuangheigu, with the fermentation broth of strain H77, use sterile water as a control, set three replicates for each, plant the rice seedlings until the three-leaf and one-heart stage, add 20 ml of fermentation broth for root irrigation respectively, and after 24 hours of fermentation broth treatment, evenly spray the Magnaporthe oryzae spore suspension on the leaves. After inoculating Magnaporthe oryzae for 7 days, investigate the incidence of rice blast, and calculate the incidence rate and disease index. The results show that the fermentation broth of the strain can reduce the incidence of rice blast. The effect of the fermentation broth of the strain on the incidence of Huangkenuo is shown in Table 3:

[0109]

[0110] The influence of the strain fermentation broth on the incidence of Lijiang Xintuanheigu is shown in Table 4 as follows:

[0111] Table 4

[0112]

[0113] The above shows and describes the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited by the above embodiments. The above embodiments and the descriptions in the specification only illustrate the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention will have various changes and improvements. The scope of protection required by the present invention is defined by the appended claims, the specification and their equivalents.

Claims

1. A Bacillus amyloliquefaciens strain for controlling rice blast, characterized in that: The rice blast control Bacillus amyloliquefaciens strain is classified and named Bacillus amyloliquefaciens H77, and is deposited in the Institute of Microbiology, Guangdong Academy of Sciences, Guangdong Microbiological Culture Collection Center, and the address of the depository is 5th Floor, Building 59, No. 100 Xianlie Middle Road, Guangzhou, and the deposit date is December 9, 2024; Deposit number: GDMCCNo.65596.

2. The rice blast control Bacillus amyloliquefaciens strain according to claim 1, characterized in that: The 16s rDNA sequence of the rice blast control Bacillus amyloliquefaciens strain is the nucleotide sequence shown in SEQ ID No.

1.

3. The rice blast control Bacillus amyloliquefaciens agent prepared by the rice blast control Bacillus amyloliquefaciens strain according to claim 1.

4. The rice blast control Bacillus amyloliquefaciens agent according to claim 3, wherein the active ingredient is at least one of the following (a), (b), and (c): (a) a fermentation culture of the rice blast control Bacillus amyloliquefaciens strain according to claim 1; (b) a spore suspension of the rice blast control Bacillus amyloliquefaciens strain obtained according to claim 1; (c) Ultrasonic lysis precipitation of the rice blast control Bacillus amyloliquefaciens strain cells obtained according to claim 1.

5. The method for preparing the rice blast control Bacillus amyloliquefaciens agent according to claim 3, characterized in that The method comprises the following steps: picking an activated single colony of Bacillus amyloliquefaciens H77 with an inoculation loop and inoculating it on 200 mL of NB culture medium, and culturing it in a shaking incubator at 33° C. and 180 rpm for 3 days for use.

6. The method for preparing the rice blast control Bacillus amyloliquefaciens agent according to claim 5, characterized in that: The NB culture medium consists of 10 g of peptone, 3 g of beef extract powder and 5 g of sodium chloride.

7. Use of the Bacillus amyloliquefaciens strain for controlling rice blast according to claim 1 or the Bacillus amyloliquefaciens agent for controlling rice blast according to claim 3 in the preparation of a preparation for controlling rice blast.

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