Morchella esculenta white mold disease biocontrol bacterial preparation and preparation method thereof

Abstract

The invention discloses a toadstool white mould disease biocontrol bacterial preparation and a preparation method thereof, and relates to the technical field of microbial bactericides, the toadstool white mould disease biocontrol bacterial preparation comprises the following raw materials by weight: 37.5 parts of Bacillus firmus fermentation broth, 0.5 part of a nano-material, 45 parts of a carrier, 5 parts of a wetting agent, 10 parts of a dispersant and 2 parts of a protective agent, the nano-material is silica, the carrier is diatomite, the wetting agent is Tween 20, and the dispersant is diatomite. The dispersant is polyvinyl alcohol, and the protective agent is dextrin; according to the toadstool white mould disease biocontrol bacterium preparation and the preparation method thereof, biocontrol bacteria are preferentially colonized at key sites such as plant rhizosphere, leaf surface or wound and the like, so that limited ecological niche is occupied, and effective infection is difficult to establish due to lack of physical space and attachment sites when pathogenic bacteria invade; by adding the nano material, the carrier, the wetting agent, the dispersing agent and the protective agent, the environmental stability and the field persistence of the biocontrol bacterium are improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of microbial fungicides, in particular to a morchella white mold disease biocontrol agent and a preparation method thereof. BACKGROUND

[0002] Morchella is a kind of edible fungus with important edible, medicinal and economic value. It has a long history of cultivation in Sichuan, Yunnan, Guizhou and other places. With the expansion of cultivation scale, diseases caused by various pathogenic fungi and bacteria are increasingly prominent, which makes the quality of morchella decline and causes serious economic losses to farmers. At present, the prevention and control of the disease mainly relies on chemical control, but the large-scale use of chemical pesticides not only easily leads to the increase of pathogen resistance, but also destroys the ecological environment. The pesticide residues on the surface of morchella also greatly reduce the quality of morchella.

[0003] Biological control is a safe method for disease and pest control, which has the advantages of environmental protection, high efficiency, economy and difficulty in developing resistance. However, the biocontrol agent also has the disadvantages of unstable field control effect and slow effect, which greatly limits the production and application of biocontrol agent. SUMMARY

[0004] The purpose of the present application is to provide a morchella white mold disease biocontrol agent and a preparation method thereof, in order to solve the problems of unstable field control effect and slow effect of biocontrol agent in the prior art.

[0005] In order to achieve the above purpose, the present application provides the following technical scheme: a morchella white mold disease biocontrol agent, the raw materials of which include 37.5 parts of bacillus firmus fermentation broth, 0.5 parts of nanometer material, 45 parts of carrier, 5 parts of humectant, 10 parts of dispersing agent and 2 parts of protective agent.

[0006] Further, the nanometer material is silicon dioxide.

[0007] Further, the carrier is diatomite.

[0008] Further, the humectant is Tween 20.

[0009] Further, the dispersing agent is polyvinyl alcohol.

[0010] Further, the protective agent is dextrin.

[0011] A preparation method of a morchella white mold disease biocontrol agent, which is suitable for preparing a morchella white mold disease biocontrol agent, comprising the following steps:

[0012] S1. Inoculate Bacillus stolonifera into LB liquid medium and culture on a shaker for 24 h at pH 7.5, temperature 35℃, and dissolved oxygen 150 to obtain primary seed culture.

[0013] S2. The primary seed culture is inoculated into LB liquid medium and cultured on a shaker for 24 hours at pH 7.5, temperature 35℃, and dissolved oxygen 150 to obtain the secondary seed culture.

[0014] S3. Take the secondary seed liquid and inoculate it into the fermentation broth at a volume ratio of 5-5.5%. Incubate the fermentation broth in an incubator at 35℃ and 180 rpm / min with shaking to obtain the Bacillus stolonifer fermentation broth.

[0015] S4. The fermentation broth of Bacillus stolonifera is mixed with nanomaterials, carriers, wetting agents, dispersants and protectants in proportions by weight. After stirring evenly, the mixture is frozen using a vacuum dryer to obtain the biocontrol agent.

[0016] Furthermore, the spore formation rate in the Bacillus stolonifer fermentation broth described in S3 is above 80%.

[0017] The application of a biocontrol agent for morel white mold disease in the prevention and control of morel white mold disease involves diluting the biocontrol agent with water and spraying it onto the surface of morel mushrooms for the prevention and control of morel white mold disease.

[0018] Furthermore, the biocontrol agent is diluted with water by a factor of 100.

[0019] Compared with existing technologies, the present invention provides a biocontrol agent for morel white mold disease and its preparation method. By preferentially colonizing key sites such as plant rhizosphere, leaf surface or wounds, the biocontrol agent occupies a limited ecological niche, resulting in a lack of physical space and attachment sites for pathogen invasion, making it difficult to establish effective infection. The environmental stability and field persistence of the biocontrol agent are increased by adding nanomaterials, carriers, wetting agents, dispersants and protectants. Attached Figure Description

[0020] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in this invention. For those skilled in the art, other drawings can be obtained based on these drawings.

[0021] Figure 1 This is a schematic diagram illustrating the results of indoor and field control of morel white mold disease using Bacillus stolonifera, as provided in an embodiment of the present invention.

[0022] Figure 2 This is a schematic diagram of the nanomaterial screening results provided in an embodiment of the present invention;

[0023] Figure 3 This is a schematic diagram of the silica concentration screening results provided in an embodiment of the present invention;

[0024] Figure 4 A schematic diagram illustrating the effect of 0.5% silica on the thermal stability of Bacillus stoichiometrica, as provided in an embodiment of the present invention.

[0025] Figure 5 This is a schematic diagram illustrating the effect of acid-base stability on the results of an embodiment of the present invention.

[0026] Figure 6 This is a schematic diagram illustrating the effects of ultraviolet stability on the results of an embodiment of the present invention.

[0027] Figure 7 This is a schematic diagram illustrating the growth of *Sporothrix sp.* in different culture media and the confrontation effect with *Bacillus spp.*, as provided in an embodiment of the present invention.

[0028] Figure 8 This is a schematic diagram of the carrier material screening results provided in an embodiment of the present invention;

[0029] Figure 9 A schematic diagram illustrating the screening results of carrier materials for wetting agents, dispersants, and protective agents provided in embodiments of the present invention;

[0030] Figure 10 This is a schematic diagram illustrating the indoor control results of the biocontrol agent provided in an embodiment of the present invention;

[0031] Figure 11 This is a schematic diagram illustrating the field control results of the biocontrol agent provided in an embodiment of the present invention. Detailed Implementation

[0032] To enable those skilled in the art to better understand the technical solution of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings.

[0033] Example 1:

[0034] A biocontrol agent for morel white mold disease, the raw materials of which include, by weight: 37.5 parts of Bacillus stolonifer fermentation broth, 0.5 parts of silica, 45 parts of diatomaceous earth, 5 parts of Tween 20, 10 parts of polyvinyl alcohol and 2 parts of dextrin.

[0035] The specific implementation method involves using 37.5 parts by weight of Bacillus stolonifer fermentation broth as the active core component of the biocontrol agent, which is fundamental to the agent's biocontrol function. Bacillus stolonifer inhibits pathogens through multiple mechanisms: it preferentially colonizes morel rhizospheres, leaf surfaces, or potential wounds through competition, seizing space and nutrient resources, making it difficult for pathogens to establish themselves; it produces antimicrobial substances (such as antibiotics, lipopeptides, enzymes, etc.) to directly inhibit or kill the pathogenic fungi causing white mold, producing an antagonistic effect; and it induces systemic resistance, activating the morel's own defense system. The 37.5 parts by weight of Bacillus stolonifer fermentation broth ensures a sufficiently high bacterial concentration (over 80% spore formation), guaranteeing that after spraying onto the target surface, a sufficient number of biocontrol bacteria colonize and exert their effects, achieving the effective dose required for optimal control.

[0036] Silica, as a nanomaterial, can increase the adhesion and spreading ability of formulations on the surface of morel mushrooms (especially hydrophobic surfaces), reducing loss; it can encapsulate or adsorb around the bacteria, providing a physical barrier to partially protect the live bacteria from ultraviolet radiation, drying, and harmful chemicals; its porous structure may help adsorb and slowly release the bacteria or their metabolites, prolonging the duration of action; and it helps prevent the aggregation of other components (especially carriers), making the formulation more uniform.

[0037] Nanomaterials are typically expensive, and only a small amount is needed to be effective. 0.5 parts by weight is a relatively low but effective ratio, designed to leverage their superior properties (such as high specific surface area and unique physicochemical properties) to improve the overall performance of the formulation (environmental stability, duration of action, and application effect), while avoiding the increased costs or potential negative impacts (such as excessive hygroscopicity or altered rheology) caused by excessive addition.

[0038] Porous diatomaceous earth serves as the primary adsorption matrix, effectively adsorbing large quantities of the Bacillus stolonifer fermentation broth (containing cells, spores, and metabolites), providing physical support and protection for the viable bacteria. It dilutes and disperses the high-concentration fermentation broth within the solid carrier, facilitating subsequent processing and the use of the final product. It also possesses a certain water-retention capacity, buffering against rapid moisture loss during drying and providing a suitable microenvironmental humidity after field application. Furthermore, it imparts a solid form to the formulation, facilitating storage, transportation, and use, and enhancing physical stability. 45 parts by weight constitute the largest component in the formulation, requiring a sufficient quantity to effectively adsorb all of the Bacillus stolonifer fermentation broth (containing significant amounts of water and solids), forming easily handled solid powder or granules. This 45-part-by-weight composition provides ample adsorption capacity, ensuring the cells are well immobilized and protected.

[0039] Tween 20, as a wetting agent, significantly reduces the surface tension of water, allowing the powder or concentrate to be quickly and completely wetted and dispersed in water during dilution, preventing clumping. When sprayed onto the surface of morel mushrooms, it helps the solution spread and wet better, increasing the coverage area, reducing droplet rolling, and ensuring full contact between the fungus and the target surface. Five parts by weight ensure that the formulation dissolves and disperses rapidly to form a uniform suspension when used (100-fold dilution), achieving good wetting and spreading effects on the morel mushroom surface.

[0040] Polyvinyl alcohol (PVA) acts as a dispersant, increasing the viscosity of aqueous solutions or forming a steric hindrance layer on the particle surface. This prevents solid particles (such as diatomaceous earth or nanomaterials with adsorbed bacteria) in the diluted formulation from settling or agglomerating too quickly, thus maintaining the uniformity and stability of the suspension. Ten parts by weight of PVA provide sufficient dispersion and stability to ensure that a 100-fold dilution remains homogeneous during spraying.

[0041] Dextrin acts as a preservative, coating bacterial cells (especially spores) to reduce mechanical damage to cell membranes and structures during ice crystal formation and dehydration, thus significantly improving viable cell survival. In the final dried product, dextrin molecules form a protective layer around the cells, partially isolating them from the effects of oxygen, moisture fluctuations, and adverse temperatures, extending shelf life. Under suitable conditions, dextrin can serve as a carbon source for spore germination and early cell growth. The amount of preservative used is usually small but crucial. Two parts by weight of dextrin is sufficient to provide an effective protective barrier for a large number of cells during freeze-drying, significantly improving viable cell yield and product storage stability.

[0042] In summary, based on ensuring a sufficient number of live biocontrol bacteria, the application performance is optimized by using carrier fixation, protectants to maintain activity, dispersants and wetting agents, and nanomaterials to enhance environmental adaptability and effectiveness. The ultimate goal is to prepare a biocontrol agent that can stably and efficiently control morel white mold under field conditions. The 100-fold dilution also confirms that this formula is a high-concentration preparation.

[0043] Example 2:

[0044] A method for preparing a biocontrol agent for morel white mold disease includes the following steps:

[0045] S1. Inoculate Bacillus stolonifera into LB liquid medium and culture on a shaker for 24 h at pH 7.5, temperature 35℃, and dissolved oxygen 150 to obtain primary seed culture.

[0046] The specific implementation method is as follows: A loopful of *Bacillus firmus* bacterial culture, preserved at -80℃ in glycerol tubes or slant agar, is picked up using a sterile inoculation loop and inoculated into LB liquid medium (pH 7.5). The inoculated medium is placed in a shaker, set to 35℃ and 150 rpm, and incubated for 24 hours (at which point the bacteria are in the logarithmic growth phase, OD600≈2.0-2.5), to obtain the primary seed culture.

[0047] S2. Inoculate the primary seed culture into LB liquid medium and culture it in a shaker for 24 hours at pH 7.5, temperature 35℃, and dissolved oxygen 150 to obtain the secondary seed culture.

[0048] The specific implementation method is as follows: the primary seed culture is transferred to fresh LB medium (pH 7.5) at a volume ratio of 5%, and the culture parameters are completely consistent with those of S1 (35℃, 150rpm, 24h) to obtain the secondary seed culture.

[0049] S3. Take the secondary seed liquid and inoculate it into the fermentation broth at a volume ratio of 5-5.5%. Incubate in an incubator at 35℃ and 180 rpm / min with shaking until the spore formation rate is above 80% to obtain the Bacillus stolonifer fermentation broth.

[0050] The specific implementation method is as follows: the secondary seed culture is inoculated into the fermenter at a volume ratio of 5-5.5%, and cultured with shaking in an incubator at 35℃ and 180 rpm / min. Samples are taken for microscopic examination every 4 hours. When the spore formation rate is ≥80% (confirmed by spore staining), which usually takes 36-48 hours, fermentation is terminated, and the temperature is immediately lowered to 4℃ to inhibit metabolism, thus obtaining the Bacillus thuringiensis fermentation broth.

[0051] S4. The fermentation broth of Bacillus stolonifera is mixed with nanomaterials, carriers, wetting agents, dispersants and protectants in proportions by weight. After stirring evenly, the mixture is frozen using a vacuum dryer to obtain the biocontrol agent.

[0052] The specific implementation method is as follows: 37.5 parts by weight of Bacillus stolonifer fermentation broth, 0.5 parts by weight of silica, 45 parts by weight of diatomaceous earth, 5 parts by weight of Tween 20, 10 parts by weight of polyvinyl alcohol and 2 parts by weight of dextrin are added to a mixing tank and stirred at low speed at 30°C for 30 minutes until uniform. The mixture is then frozen at -80°C for 4 hours using a vacuum dryer, and then dried at a vacuum degree of 1-10 Pa and a temperature of -50°C for 24-36 hours. After drying, the mixture is pulverized to a particle size ≤100μm to obtain the biocontrol agent, which is then sealed and stored away from light.

[0053] Example 3:

[0054] Please see Figure 1This embodiment provides a technical solution based on Embodiment 1: screening of optimal culture conditions for Bacillus stolonifer (biocontrol bacteria) and determination of its preventive efficacy.

[0055] By studying the antagonistic effect of the biocontrol bacteria's sterile metabolites on the pathogen, the optimal temperature, pH, aeration rate, and fermentation conditions for the bacteria's growth were screened. Based on this, single colonies of the biocontrol bacteria and mycelial cakes of the pathogen (longisporum ova and monoseptum) were inoculated into LB and PDB liquid media, respectively, and cultured by shaking for later use. Healthy, mature morel mushrooms were selected for indoor and field control trials. Disease index and control efficacy were calculated based on disease grading standards.

[0056] Please see Figure 1 A-1 and B-1 were inoculated with the pathogen first, followed by the biocontrol bacteria; A-2 and B-2 were inoculated with both the pathogen and biocontrol bacteria simultaneously; A-3 and B-3 were inoculated with the biocontrol bacteria first, followed by the pathogen; A-4 and B-4 were inoculated with only sterile liquid culture medium. The results showed that *Bacillus stolonifer* exhibited the best antagonistic effect against *L. spp.*, the pathogen of *Alternaria alternata*, at pH 7.5, temperature 35℃, and dissolved oxygen 150 g / L. Indoor control test results are as follows... Figure 1 As shown in Figures A-1, A-2, A-3, and A-4, statistically, when the pathogen was inoculated first followed by the biocontrol agent, the disease index was 50%; when both the biocontrol agent and the pathogen were inoculated simultaneously, the disease index was 35%; and when the biocontrol agent was inoculated first followed by the pathogen, the disease index was 15%. Field control trial results are as follows... Figure 1 As shown in Figures B-1, B-2, B-3, and B-4, statistically, the disease index was 55% when the pathogen was inoculated first, followed by the biocontrol bacteria; 37.5% when both biocontrol bacteria and the pathogen were inoculated simultaneously; and 20% when the biocontrol bacteria were inoculated first, followed by the pathogen. Regardless of whether control was carried out indoors or in the field, the disease index of the positive control group (inoculated only with the pathogen) was 75%, while the disease index of the blank control group (inoculated only with sterile culture medium) was 0.

[0057] Therefore, the results showed that in both indoor and field control, the control effect of pre-inoculation with biocontrol solution was the best, at 80% and 73.3% respectively. However, the control effect of pre-inoculation with pathogen followed by inoculation with biocontrol was only 33% and 26.7% respectively. The control effect of inoculation with both pathogen and biocontrol was 53% and 50% respectively.

[0058] Example 4:

[0059] Please see Figures 2 to 7 This embodiment provides a technical solution based on Embodiment 1: screening of biocontrol nanomaterials and determination of their stability and antibacterial properties.

[0060] The optimal nanomaterials for biocontrol bacteria were screened from seven types of nanomaterials: nano-titanium dioxide, iron powder, silicon dioxide, cerium oxide, zinc oxide, aluminum oxide, and carbon powder. After determining the optimal nanomaterial types, concentrations of 0.01%, 0.05%, 0.1%, 0.5%, 1%, and 5% were selected to screen for the optimal nanomaterial concentrations. Finally, the effects of these nanomaterials on the thermal stability, acid-base stability, and UV stability of the biocontrol bacteria were determined. The inhibition rate of the biocontrol bacteria against pathogens was measured in PDA medium containing the aforementioned optimal nanomaterials.

[0061] Please see Figure 2 and Figure 3 Preliminary screening results for *Bacillus stolonifer* nanomaterials indicate that 0.5% silica is the optimal material. Please refer to [link / reference]. Figures 4 to 6 At different temperatures Figure 4 ), different pH ( Figure 5 ) and at different UV irradiation times ( Figure 6 Under certain conditions, nanomaterials containing 0.5% silica can enhance the heat resistance, acid and alkali resistance, and UV resistance of *Bacillus stoichiometrics*. Please refer to [link / reference]. Figure 7 The antibacterial test results showed that the growth of pathogens was more significantly inhibited on the culture medium with 0.5% silica, with an average inhibition rate of 41.03%, which was significantly higher than the 24.44% with sterile water. Therefore, the biocontrol nanocomposite agent has a better inhibitory effect on pathogens than biocontrol bacteria alone.

[0062] Example 5:

[0063] Please see Figure 8 and Figure 9 This embodiment provides a technical solution based on Embodiment 1: screening of carriers and adjuvant materials (wetting agents, dispersants, and protectants) in biocontrol agents.

[0064] Carriers were screened from kaolin, diatomaceous earth, calcium carbonate, talc, and bentonite powder; wetting agents were screened from sodium dodecylbenzenesulfonate, Tween 20, and chelating agents; dispersants were screened from sodium lignosulfonate, sodium tripolyphosphate, sodium carboxymethyl cellulose, polyvinyl alcohol, and polyethylene glycol powder; and protective agents were screened from humic acid, dextrin, sodium dodecylbenzenesulfonate, and kaolin. The screened carriers and additives were tested according to test table L9(3). 4 Orthogonal experiments were conducted to count the number of colonies on the plates and determine the proportions of each component. The biocontrol bacteria fermentation broth was mixed and stirred according to the proportions, and then frozen using a vacuum dryer to prepare a wettable powder. After passing the quality test according to the standard methods issued by the Ministry of Agriculture and Rural Affairs of the People's Republic of China and the State Administration for Quality Supervision, Inspection and Quarantine of the People's Republic of China, it was put into use.

[0065] Please see Figure 8The screening results for carriers and adjuvants showed that diatomaceous earth was the optimal carrier for Bacillus stolonifera (Factor A); please refer to [link to relevant documentation]. Figure 9 The screening results of the adjuvants showed that the optimal dispersant was polyvinyl alcohol (factor B), the optimal wetting agent was Tween 20 (factor C), and the optimal protectant was dextrin (factor D). Please refer to the table below. Orthogonal experiments revealed that the order of influence of different wettable powder formulations on the growth activity of *Bacillus stolonifer* was A > C > B > D. Furthermore, the culture medium prepared with the combination A3B3C3D2 showed the best growth. Therefore, the optimal ratio of 45 parts by weight of carrier, 5 parts by weight of dispersant, 10 parts by weight of wetting agent, and 2 parts by weight of protectant was selected as the optimal ratio for the wettable powder.

[0066]

[0067] Example 6:

[0068] Please see Figure 10 and Figure 11 This embodiment provides a technical solution based on Embodiment 1: determination of the control effect of biocontrol agents on morel white mold disease.

[0069] The biocontrol agent was diluted 100, 500, and 1000 times with sterile distilled water for later use. A commercially available 50% carbendazim wettable powder was diluted 500 times as a control agent. The biocontrol fermentation broth served as the bacterial control, and the sterile water treatment served as a blank control. Indoor and field control experiments were conducted in the university's laboratory and greenhouse, using the same methods as in Example 3.

[0070] Please see Figure 10 According to the results of indoor control experiments, the disease indices of pre-inoculated biocontrol agents diluted 100, 500, and 1000 times, commercially available 50% carbendazim diluted 500 times, Bacillus thuringiensis fermentation broth, and sterile water were 10%, 35%, 50%, 15%, 15%, and 75%, respectively. The control effects were 86.7%, 53.3%, 33.3%, 76.5%, 80%, 80%, and 0%, respectively.

[0071] Please see Figure 11 Field control trials showed that, according to statistics, pre-inoculation with 100x, 500x, and 1000x dilutions of biocontrol agents, a 500x dilution of commercially available 50% carbendazim, Bacillus thuringiensis fermentation broth, and sterile water resulted in disease indices of 10%, 35%, 50%, 15%, 20%, and 80%, respectively. The control efficacy was 87.5%, 56.3%, 37.5%, 76.5%, 75%, and 0%, respectively. Therefore, both indoor and field control results indicate that pre-inoculation with a 100x dilution of biocontrol agents is most effective against morel white mold.

[0072] The foregoing has only described certain exemplary embodiments of the present invention by way of illustration. Undoubtedly, those skilled in the art can modify the described embodiments in various ways without departing from the spirit and scope of the present invention. Therefore, the foregoing drawings and descriptions are illustrative in nature and should not be construed as limiting the scope of protection of the claims of the present invention.

Claims

1. A preparation of a Morchella white-rot disease biocontrol agent, characterized by, The raw materials include 37.5 parts of Bacillus firmus fermentation liquor, 0.5 parts of nanometer material, 45 parts of carrier, 5 parts of wetting agent, 10 parts of dispersing agent and 2 parts of protective agent.

2. The preparation of a biocontrol fungus of Morchella white blight according to claim 1, characterized in that, The nanometer material is silicon dioxide.

3. The preparation of a biocontrol fungus against white mold disease of Morchella according to claim 1, characterized in that, The carrier is diatomite.

4. The preparation of a biocontrol fungus against white mold disease of Morchella according to claim 1, characterized in that, The wetting agent is Tween 20.

5. The preparation of a biocontrol fungus against white mold disease of Morchella according to claim 1, characterized in that, The dispersing agent is polyvinyl alcohol.

6. The preparation of a biocontrol fungus against white mold disease of Morchella according to claim 1, characterized in that, The protective agent is dextrin.

7. A method for preparing a preparation of a Morchella white-rot disease biocontrol agent, characterized by, The preparation method is suitable for preparing the Morchella white mold disease biocontrol agent preparation of any one of claims 1-6, and comprises the following steps: S1, inoculating Bacillus firmus into LB liquid medium, and culturing for 24 h under the conditions of pH 7.5, temperature 35℃ and dissolved oxygen 150, to obtain primary seed liquor; S2, inoculating the primary seed liquor into LB liquid medium, and culturing for 24 h under the conditions of pH 7.5, temperature 35℃ and dissolved oxygen 150, to obtain secondary seed liquor; S3, taking the secondary seed liquor, inoculating into fermentation liquor at a volume ratio of 5-5.5%, and culturing in a 35℃ and 180 rpm / min incubator, to obtain Bacillus firmus fermentation liquor; S4, mixing the Bacillus firmus fermentation liquor with nanometer material, carrier, wetting agent, dispersing agent and protective agent according to the weight ratio, stirring uniformly, and then freezing by using a vacuum drying instrument to obtain the biocontrol agent preparation.

8. The preparation method of the Morchella white mold disease biocontrol bacteria preparation according to claim 7, characterized in that, The Bacillus firmus fermentation liquor in S3 has a spore formation amount of more than 80%.

9. The use of the preparation of Morchella white mold disease biocontrol bacteria according to any one of claims 1-6 in the prevention and treatment of Morchella white mold disease, characterized in that, After diluting the biocontrol agent preparation with water, spraying on the surface of Morchella, the biocontrol agent preparation is used for preventing and treating Morchella white mold disease.

10. The use of the Morchella white mold disease biocontrol bacteria preparation according to claim 9 in the prevention and treatment of Morchella white mold disease, characterized in that, The dilution multiple of the biocontrol agent preparation is 100 times.

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