Bacillus velezensis XZT106 and application thereof

Abstract

The invention belongs to the technical field of fermentation engineering and microbial disease control, and particularly relates to bacillus velezensis XZT106 and application thereof. The invention provides bacillus velezensis XZT106, the preservation number of the bacillus velezensis XZT106 is CCTCC (China Center For Type Culture Collection) M 2025518, and tests show that the bacillus velezensis XZT106 can be used for treating phellinus noxius, botrytis cinerea, colletotrichum gloeosporioides, alternaria tenuissima, fusarium oxysporum, phytophthora capsici and fusarium solanum s.

Description

Technical Field

[0001] The invention belongs to the technical field of fermentation engineering and microbial disease prevention and control, and particularly relates to a strain of Bacillus velezensis XZT106 and an application thereof. Background Art

[0002] Bacillus velezensis, a new species of the genus Bacillus, is a Gram-positive aerobic bacterium with a rod-shaped body measuring 0.5×(1.5−3.5) μm and endospores. It is widely distributed in nature, including water, soil, air, plant roots, plant surfaces, and animal intestines. It is widely used in the biological control of animal and plant diseases because it can produce a variety of secondary metabolites and has broad-spectrum antibacterial activity and growth-promoting effects.

[0003] In recent years, the long-term use and even overuse of chemical drugs such as antibiotics and disinfectants has led to the emergence of drug-resistant bacteria, posing a serious threat to human health. In agricultural production, the overuse of chemical pesticides has led to drug resistance in plant and animal pathogens, making disease prevention and control more difficult. Pesticide residues also pollute soil and water, disrupting the microecological balance.

[0004] Biopesticides are a type of pesticide developed from biological resources, boasting unique eco-friendliness and targeted properties. Modern biopesticides are not limited to living organisms but also include their metabolites, genetically modified products, and synthetic biochemical pesticides with similar structures to natural compounds. Based on their chemical composition, biopesticides are categorized as biochemical pesticides, microbial pesticides, genetically modified biological pesticides, and natural enemy pesticides. Microbial pesticides are pesticides derived from active substances in nature, whose active ingredients can be extracted through specific technological means. They play a vital role in plant protection and pest control.

[0005] Brown root disease (Ganoderma pseudoferreum) is the most serious of seven root diseases affecting rubber trees in my country and one of the most serious worldwide. It attacks the roots or root collar of rubber trees, causing leaves to shrink and turn yellow, the crown to thin out, the trunk to shrink, roots to rot, and ultimately, the entire plant to die. This severely shortens the economic life of the rubber plantation and reduces rubber yield. The traditional pesticide for controlling brown root disease in rubber trees is tridemorph EC (75% w / w). In recent years, there has been some success using triadimefon WP (15% w / w), but the available pesticides remain limited.

[0006] In terms of plant disease prevention and control, the biocontrol effect of Bacillus velez is particularly outstanding. However, there is no report in the existing technology on whether Bacillus velez can antagonize pathogenic microorganisms such as wood-forming fungi. Summary of the Invention

[0007] In order to solve the above technical problems, the present invention provides a strain of Bacillus velezensis XZT106 and applications thereof.

[0008] The present invention discloses a strain of Bacillus velezensis XZT106. The strain of Bacillus velezensis XZT106 was deposited in the China Center for Type Culture Collection on March 18, 2025, with a deposit number of CCTCC M 2025518. The deposit address is: Wuhan University, Wuhan, China.

[0009] The invention discloses a microbial agent, which contains Bacillus velezensis XZT106.

[0010] The present invention discloses a method for preparing a microbial agent containing Bacillus velezensis XZT106 by fermentation, the method comprising the following steps:

[0011] (1) Strain activation: Bacillus velezensis XZT106 was inoculated onto LB solid medium and cultured at 30-35°C for 1-2 days to obtain an activated strain; the formula of the LB solid medium was as follows: tryptone 8-12 g / L, yeast extract 4-6 g / L, sodium chloride 8-12 g / L, agar powder 14-16 g / L, pH 7.0 ± 0.2, and autoclaved at 121°C for 30 min;

[0012] (2) Fermentation seed culture: The activated Bacillus velezensis XZT106 was inoculated into LB liquid culture medium and cultured in a shaker at 160-200 rpm at 28-32°C for 8-10 hours to obtain Bacillus velezensis XZT106 seed liquid; the formula of the LB liquid culture medium was as follows: 8-12 g / L tryptone, 4-6 g / L yeast extract, 8-12 g / L sodium chloride, 40-60 mmol / L zinc sulfate, 1000-1200 nmol / L PQQ, pH 7.0±0.2, and sterilized by high pressure at 121°C for 30 min;

[0013] (3) Fermentation: Inoculate the seed liquid of Bacillus velezensis XZT106 into the fermentation medium of the fermenter at an inoculum amount of 1% of the mass of the fermentation medium, and culture in a shaker at 190-220 rpm at 28-32°C for 12-24 hours to prepare a microbial agent containing Bacillus velezensis XZT106.

[0014] Preferably, the concentration of Bacillus velezensis XZT106 in the microbial agent is 1×10 6 -10 9 cfu / ml.

[0015] The present invention discloses a method for preparing a microbial agent containing Bacillus velezensis XZT106 by fermentation, the method comprising the following steps:

[0016] (1) Preparation of bacterial suspension: Place the Bacillus velezensis XZT106 bacterial suspension in a centrifuge tube and centrifuge at 5000 rpm for 8 min at 4°C. Discard the supernatant and add physiological saline to the volume before centrifugation. Repeat this process three times to obtain a clear supernatant. Finally, suspend the bacterial slurry in physiological saline and vortex to mix it thoroughly.

[0017] (3) Preparation of protective agent: dissolve the vacuum freeze-dried protective agent in distilled water to prepare a protective agent solution with a mass fraction of 8%, sterilize it, and mix it with the bacterial suspension; the vacuum freeze-dried protective agent contains the following components by mass: 100×10 3 -200×10 3 skimmed milk powder, 260×10 3 -370×10 3 Mannitol, 50×10 3 -90×10 3 parts sodium glutamate, 1-3 parts PQQ and 120×10 3 -230×10 3 1 portion of tryptone;

[0018] (4) Vacuum freeze drying: The protective agent prepared in step (3) was added to the bacterial suspension at a volume ratio of 1:1. The centrifuge tube cap was removed and replaced with a sealing film, and pre-frozen at −80°C for 4 h. The pre-frozen sample was taken out and quickly placed in a freezing trap. The sample was freeze-dried using a vacuum freeze dryer. After it was completely powdered, it was vacuum-packaged and stored in a dry place for later use. Thus, a freeze-dried preparation of Bacillus velezensis XZT106 was obtained.

[0019] A biopesticide comprising Bacillus velezensis XZT106 and / or a fermentation product of Bacillus velezensis XZT106.

[0020] Preferably, the fermentation product of Bacillus velezensis XZT106 comprises the following components: benzothiazole, cucurbitacin B, dihydroxyindole, L-histidinol, histamine, citicoline, 4-methyl-5-(β-hydroxyethyl)thiazole, 20-carboxyleukotriene B4, 2-oxo-3-methylbutyric acid, 3,4-dihydroxymandelic acid, 1,3,4-tricarboxylic acid inositol, brassinolide, tylosin, cinnamic acid (trans), S-methyl-L-cysteine ​​and 2,6-dibromophenol.

[0021] Preferably, the mass ratio of the benzothiazole, cucurbitacin B, dihydroxyindole, L-histidinol, histamine, citicoline, 4-methyl-5-(β-hydroxyethyl)thiazole, 20-carboxyleukotriene B4, 2-oxo-3-methylbutyric acid, 3,4-dihydroxymandelic acid, 1,3,4-tricarboxylic acid inositol, brassinolide, tylosin, cinnamic acid (trans), S-methyl-L-cysteine ​​and 2,6-dibromophenol is: 1-3:6-15:4-17:3-12:4-6:12-18:4-8:1-5:5-9:6-20:5-8:4-9:3-5:3-5:6-8:15-19.

[0022] Preferably, the mass fraction of the benzothiazole, cucurbitacin B, dihydroxyindole, L-histidinol, histamine, citicoline, 4-methyl-5-(β-hydroxyethyl)thiazole, 20-carboxyleukotriene B4, 2-oxo-3-methylbutyric acid, 3,4-dihydroxymandelic acid, 1,3,4-tricarboxylic acid inositol, brassinolide, tylosin, cinnamic acid (trans), S-methyl-L-cysteine ​​and 2,6-dibromophenol in the fermentation product of Bacillus velezensis XZT106 is 0.5-10%.

[0023] A method for preparing a biological pesticide comprises fermenting Bacillus velezensis XZT106 in a fermentation medium.

[0024] Disclosed is a use of Bacillus velezensis XZT106 or a microbial agent containing the same or a biopesticide containing the same in inhibiting the growth of plant pathogens, wherein the plant pathogens include at least one of: Phyllosporium occidentalis, Botrytis cinerea, Colletotrichum gloeosporioides, Alternaria tenuis, Fusarium oxysporum, Phytophthora capsici, Fusarium solani and Colletotrichum camelliae.

[0025] Bacillus velezensis XZT106 or a microbial agent containing the same or a biological pesticide containing the same is used in the preparation of a product for inhibiting the growth of plant pathogens, wherein the plant pathogens include at least one of: Psoralea corylifolia, Botrytis cinerea, Colletotrichum gloeosporioides, Alternaria tenuis, Fusarium oxysporum, Phytophthora capsici, Fusarium solani and Colletotrichum camelliae.

[0026] Disclosed is the use of Bacillus velezensis XZT106, a microbial agent containing the same, or a biological pesticide containing the same in the preparation of products for preventing and controlling rubber tree brown root disease, tomato gray mold, pepper anthracnose, pepper black spot, eggplant wilt, pepper blight, pepper root rot, and tea anthracnose.

[0027] Beneficial effects of the present invention:

[0028] The present invention provides a Bacillus velezensis XZT106. Experiments have shown that the Bacillus velezensis XZT106 has good antagonistic effects on Phellinus noxius, Botrytis cinerea, Colletotrichum gloeosporioides, Alternaria alternata, Fusarium oxysporum, Phytophthora capsici, Fusarium solani and Colletotrichum camelliae. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 The results show the inhibitory effect of Bacillus Velez XZT106 on Phyllosporium, Botrytis cinerea, Colletotrichum gloeosporioides, Alternaria tenuis, Fusarium oxysporum, Phytophthora capsici, Fusarium solani and Colletotrichum camelliae. DETAILED DESCRIPTION

[0030] To make the objectives, technical solutions, and advantages of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments 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 making creative efforts shall fall within the scope of protection of the present invention.

[0031] The present invention provides a strain of Bacillus velezensis XZT106. Bacillus velezensis XZT106 was deposited with the China Center for Type Culture Collection on March 18, 2025, at Wuhan University, Wuhan, China, with accession number CCTCC M 2025518.

[0032] Example 1 Identification, Purification and Preservation of Bacillus velezensis XZT106 Strain

[0033] (1) Identification

[0034] The 16S rRNA gene of the strain Bacillus velezensis XZT106 of the present invention was amplified. The PCR product was sequenced and the resulting gene sequence (the nucleotide sequence of the 16S rRNA gene is shown in SEQ ID NO. 1) was compared and analyzed at NCBI to clarify the taxonomic status of the strain. The sequencing results were then compared using BLAST on the NCBI website to determine the taxonomic status of closely related bacterial strains. The comparison results showed that the strain was 100% related to Bacillus velezensis, and the strain was named Bacillus velezensis XZT106.

[0035] SEQ ID NO.1

[0036]

[0037] (2) Purification and preservation of bacterial strains

[0038] Using the plate streak method, streak the initially isolated Bacillus velezensis XZT106 onto a new LB plate, place it in a 28°C biochemical incubator, invert and incubate for at least 24 hours, pick a single colony, and number it XZT106. Inoculate the Bacillus velezensis XZT106 strain into LB liquid medium and incubate it in a shaker at 28°C and 200 rpm for 24 hours. Then, pipette 1 mL of the fermentation broth from the Bacillus velezensis XZT106 strain with 1 mL of 50% sterile glycerol, gently shake, and store at -80°C for long-term storage.

[0039] Example 2 Preparation of Bacillus velezensis XZT106 Microbial Agent or Biopesticide

[0040] The specific preparation process is as follows:

[0041] (1) Strain activation: Inoculate Bacillus velezensis XZT106 on LB solid medium and culture at 30-35°C for 1-2 days to obtain an activated strain;

[0042] LB solid medium (g / L): 8-12 g / L tryptone, 4-6 g / L yeast extract, 8-12 g / L sodium chloride, 14-16 g / L agar powder, dissolve in water, and finally adjust the volume to 1000 mL, pH 7.0 ± 0.2, and sterilize by high pressure (121°C, 30 min).

[0043] (2) Fermentation seed culture: The activated Bacillus velezensis XZT106 was inoculated into LB liquid culture medium and cultured in a shaker at 160-200 rpm at 28-32°C for 8-10 hours to obtain Bacillus velezensis XZT106 seed liquid;

[0044] The LB liquid culture medium (g / L): 8-12 g / L tryptone, 4-6 g / L yeast extract, 8-12 g / L sodium chloride, 40-60 mmol / L zinc sulfate, 1000-1200 nmol / L PQQ, pH 7.0±0.2, and was sterilized by high pressure (121° C., 30 min).

[0045] (3) Fermentation: Inoculate the seed liquid of Bacillus velezensis XZT106 into the fermentation medium of the fermenter at an inoculum rate of 1% of the mass of the fermentation medium, and culture in a shaker at 190-220 rpm at 28-32°C for 12-24 hours to obtain a microbial agent or biopesticide containing Bacillus velezensis XZT106 (with a colony concentration of (1-3) × 10 6 -10 9 cfu / ml).

[0046] The fermentation medium has a formula of: 18-25 g / L soybean meal, 14-16 g / L glucose, 8-12 g / L magnesium sulfate, 40-60 mmol / L zinc sulfate, 15-20 g / L peptone, 10-15 g / L yeast extract, 8-12 g / L sodium chloride, 8-12 g / L potassium dihydrogen phosphate, and 1000-1200 nmol / L PQQ. The pH of the fermentation tank is 7.0±0.2.

[0047] Testing revealed that the fermentation product of Bacillus velezensis XZT106 contains the following components: benzothiazole, cucurbitacin B, dihydroxyindole, L-histidinol, histamine, citicoline, 4-methyl-5-(β-hydroxyethyl)thiazole, 20-carboxyleukotriene B4, 2-oxo-3-methylbutyric acid, 3,4-dihydroxymandelic acid, inositol 1,3,4-tricarboxylate, brassinolide, tylosin, cinnamic acid (trans), S-methyl-L-cysteine, and 2,6-dibromophenol, with the mass ratios being 1-3:6-15:4-17:3-12:4-6:12-18:4-8:1-5:5-9:6-20:5-8:4-9:3-5:3-5:6-8:15-19. The mass fraction of the total mass in the fermentation product of Bacillus velezensis XZT106 is 0.5-10%.

[0048] Example 3 Preparation of Lyophilized Formulation of Bacillus velezensis XZT106

[0049] (1) Preparation of bacterial suspension: The bacterial suspension obtained by fermentation in Example 2 was placed in a centrifuge tube and centrifuged at 5000 rpm for 8 min at 4°C. The supernatant was discarded and physiological saline was added to the volume before centrifugation. This process was repeated three times to obtain a clear supernatant. Finally, the bacterial sludge was suspended in physiological saline and thoroughly mixed by vortexing.

[0050] (3) Preparation of protective agent: The vacuum freeze-dried protective agent was dissolved in distilled water according to the formula to prepare a protective agent solution with a concentration of 8% (mass fraction), and after sterilization, mixed with the bacterial suspension; the vacuum freeze-dried protective agent contained the following components by mass: 100×10 3 -200×10 3 skimmed milk powder, 260×10 3 -370×10 3 Mannitol, 50×10 3 -90×10 3 parts sodium glutamate, 1-3 parts PQQ and 120×10 3 -230×10 3 Tryptone.

[0051] (4) Vacuum freeze drying: Add the protective agent prepared in step (3) to the bacterial suspension at a volume ratio of 1:1. Remove the centrifuge tube cap and replace it with a sealing film. Prefreeze at −80°C for 4 h. Take out the prefrozen sample and quickly place it in a freezing trap. Use a vacuum freeze dryer to freeze-dry the sample. After it is completely powdered, vacuum package it and store it in a dry place for future use. This will obtain a freeze-dried preparation of Bacillus velezensis XZT106.

[0052] Example 4 Confrontation experiment of Bacillus velezensis XZT106 against Phyllosporium occidentalis, Botrytis cinerea, Colletotrichum gloeosporioides, Alternaria tenuis, Fusarium oxysporum, Phytophthora capsici, Fusarium solani and Colletotrichum camelliae

[0053] The plate confrontation method was used to determine the antagonistic effect of Bacillus velezensis 106 against Phellinus noxius, Botrytis cinerea, Colletotrichum gloeosporioides, Alternaria alternata, Fusarium oxysporum, Phytophthora capsici, Fusarium solani, and Colletotrichum camelliae. The specific operation method is as follows: Under a sterile environment, a 7 mm punch was used to obtain a pathogen cake and the cake was placed in the center of a PDA plate. Subsequently, strain 106 was inoculated around 2 cm from the center of the plate. The culture medium inoculated with only the pathogen was used as the control group. Each treatment was repeated 3 times and cultured in a constant temperature incubator at 25°C for 7-10 days. The pathogen colony diameter was determined by the cross method and the inhibition rate was calculated. The results are shown in the table. Figure 1As shown in Table 1, Bacillus velezensis XZT106 has a good antagonistic effect on Phyllosporium xylophilum, Botrytis cinerea, Colletotrichum gloeosporioides, Alternaria tenuis, Fusarium oxysporum, Phytophthora capsici, Fusarium solani and Colletotrichum camelliae.

[0054] Inhibition rate (%) = (control colony diameter - treated colony diameter) / control colony diameter * 100%

[0055] Table 1 Inhibition rate of Bacillus velezensis 106 against 8 pathogens

[0056] Pathogen type Pathogen corresponding to the disease name Processing diameter / cm Control diameter / cm Antibacterial rate / % Foliar Brown root disease of rubber trees 2.53±0.08 7.80±0.04 67.56±0.97 Botrytis cinerea Tomato gray mold 1.75±0.08 7.55±0.06 76.82±1.09 Colletotrichum gloeosporioides pepper anthracnose 1.82±0.04 8.10±0.09 77.57±0.42 Alternaria tenuis Pepper black spot 2.64±0.05 8.00±0.14 66.97±0.77 Fusarium oxysporum Eggplant wilt 3.35±0.08 8.40±0.09 60.12±1.08 Phytophthora capsici Pepper blight 3.08±0.09 8.50±0.00 63.82±1.04 Fusarium solani Pepper root rot 3.04±0.14 6.50±0.06 53.20±2.28 Colletotrichum camelliae Tea Anthracnose 2.62±0.09 7.55±0.08 65.33±1.58

[0057] Application Example 1 Experiment on the Control of Brown Root Disease of Rubber Trees by Bacillus Velezii XZT106

[0058] Application Method: Dig a 30-40 cm deep and approximately 20 cm wide circular trench around the base of rubber plants during the brown root disease outbreak. Water each rubber plant with 2000 ml of a 100-fold dilution of the biopesticide solution prepared in Example 2 or 100 g of the freeze-dried formulation of Bacillus velezensis XZT106 prepared in Example 3. Forty days after application, conduct a disease survey and record the red root disease status of rubber trees in nine plots (25 trees per plot).

[0059] Investigation Method: Dig up the base of the rubber plant and observe whether the taproot is rotted before applying the pesticide. Plants with rot are diseased, while those without rot are healthy. After applying the pesticide, observe whether the taproot is rotten and whether new roots have grown. Plants with rot and no new roots are diseased, while plants with no rot or rot but new roots are healthy.

[0060] Data processing: The control effect was calculated based on the diseased plant rate in the survey results and statistical analysis was performed. The calculation formula is: Control Effect = (Number of diseased plants before application - Number of diseased plants after application) * 100 / Number of diseased plants before application.

[0061] Table 2 Effects of different treatments on the control of rubber tree brown root disease by Bacillus Velez XZT106

[0062] deal with Number of diseased plants before application Number of diseased plants after application Control effect (%) Control group 1 25 25 0 Control group 2 25 25 0 Control group 3 25 25 0 Experimental Group 1 25 8 68 Experimental Group 2 25 6 76 Experimental Group 3 25 8 68 Experimental Group 4 25 5 80 Experimental Group 5 25 4 84 Experimental Group 6 25 5 80

[0063] In Table 2, experimental groups 1-3 were treated with biopesticide solutions, and experimental groups 4-6 were treated with freeze-dried formulations. The results showed that fermentation solutions of Bacillus velezensis XZT106, prepared as solutions or freeze-dried formulations, had a significant control effect on rubber tree brown root disease, with the highest efficacy reaching 84%.

Claims

1. A strain of Bacillus velezensis XZT106, characterized in that: The Bacillus velezensis XZT106 was deposited in the China Center for Type Culture Collection on March 18, 2025, with the deposit number being CCTCC M 2025518.

2. A microbial agent, characterized in that: The microbial agent comprises the Bacillus velezensis XZT106 according to claim 1.

3. A method for preparing the microbial agent according to claim 2 by fermentation, characterized in that: The method comprises the following steps: (1) Strain activation: Bacillus velezensis XZT106 was inoculated onto LB solid medium and cultured at 30-35°C for 1-2 days to obtain an activated Bacillus velezensis XZT106 strain; the LB solid medium had the following formula: tryptone 8-12 g / L, yeast extract 4-6 g / L, sodium chloride 8-12 g / L, agar powder 14-16 g / L, pH 7.0 ± 0.2, and autoclaved at 121°C for 30 min; (2) Fermentation seed culture: The activated Bacillus velezensis XZT106 strain was inoculated into LB liquid culture medium, and cultured in a shaker at 160-200 rpm at 28-32°C for 8-10 hours to obtain Bacillus velezensis XZT106 seed liquid; the formula of the LB liquid culture medium was as follows: 8-12 g / L tryptone, 4-6 g / L yeast extract, 8-12 g / L sodium chloride, 40-60 mmol / L zinc sulfate, 1000-1200 nmol / L PQQ, pH 7.0±0.2, and sterilized by high pressure at 121°C for 30 min; (3) Fermentation: The Bacillus velezensis XZT106 seed liquid is inoculated into the fermentation medium of the fermenter at an inoculum amount of 1% of the mass of the fermentation medium, and the culture is shaken at 190-220 rpm in a shaker at 28-32° C. for 12-24 hours to prepare a microbial agent containing Bacillus velezensis XZT106.

4. The microbial agent according to claim 3, characterized in that The concentration of Bacillus velezensis XZT106 in the microbial agent is 1-3×10 6 -10 10 cfu / ml.

5. A method for preparing the microbial agent according to claim 3, characterized in that: The method comprises the following steps: (1) Preparation of bacterial suspension: Place Bacillus velezensis XZT106 bacterial suspension in a centrifuge tube and centrifuge at 5000 rpm for 8 min at 4°C. Discard the supernatant and add physiological saline to the volume before centrifugation. Repeat this process three times to obtain a clear supernatant. Finally, suspend the bacterial sludge in physiological saline and vortex to mix it thoroughly to obtain a bacterial suspension. (3) Preparation of protective agent: dissolve the vacuum freeze-dried protective agent in distilled water to prepare a protective agent solution with a mass fraction of 8%, sterilize it, and mix it with the bacterial suspension; the vacuum freeze-dried protective agent contains the following components by mass: 100×10 3 -200×10 3 skimmed milk powder, 260×10 3 -370×10 3 Mannitol, 50×10 3 -90×10 3 parts sodium glutamate, 1-3 parts PQQ and 120×10 3 -230×10 3 1 portion of tryptone; (4) Vacuum freeze drying: the protective agent prepared in step (3) is added to the bacterial suspension in step (1) at a volume ratio of 1:1, the centrifuge tube cap is removed and replaced with a sealing film, and the sample is pre-frozen at −80° C. for 4 h to obtain a pre-frozen sample; the pre-frozen sample is taken out and quickly placed in a freezing trap, and the sample is freeze-dried using a vacuum freeze dryer. After the sample is completely powdered, a freeze-dried preparation of Bacillus velezensis XZT106 is obtained.

6. A biological pesticide, characterized in that: The biopesticide comprises the Bacillus velezensis XZT106 according to claim 1 and / or a fermentation product of Bacillus velezensis XZT106.

7. The biopesticide according to claim 6, characterized in that The fermentation product of Bacillus velezensis XZT106 contains the following components: benzothiazole, cucurbitacin B, dihydroxyindole, L-histidinol, histamine, citicoline, 4-methyl-5-(β-hydroxyethyl)thiazole, 20-carboxyleukotriene B4, 2-oxo-3-methylbutyric acid, 3,4-dihydroxymandelic acid, 1,3,4-tricarboxylic acid inositol, brassinolide, tylosin, cinnamic acid (trans), S-methyl-L-cysteine ​​and 2,6-dibromophenol.

8. The biopesticide according to claim 7, characterized in that The mass ratio of the benzothiazole, cucurbitacin B, dihydroxyindole, L-histidinol, histamine, citicoline, 4-methyl-5-(β-hydroxyethyl)thiazole, 20-carboxyleukotriene B4, 2-oxo-3-methylbutyric acid, 3,4-dihydroxymandelic acid, 1,3,4-tricarboxylic acid inositol, brassinolide, tylosin, cinnamic acid (trans), S-methyl-L-cysteine ​​and 2,6-dibromophenol is: 1-3:6-15:4-17:3-12:4-6:12-18:4-8:1-5:5-9:6-20:5-8:4-9:3-5:3-5:6-8:15-19.

9. The biopesticide according to claim 8, characterized in that The mass fraction of the benzothiazole, cucurbitacin B, dihydroxyindole, L-histidinol, histamine, citicoline, 4-methyl-5-(β-hydroxyethyl)thiazole, 20-carboxyleukotriene B4, 2-oxo-3-methylbutyric acid, 3,4-dihydroxymandelic acid, 1,3,4-tricarboxylic acid inositol, brassinolide, tylosin, cinnamic acid (trans), S-methyl-L-cysteine ​​and 2,6-dibromophenol in the fermentation product of Bacillus velezensis XZT106 is 0.5-10%.

10. A method for preparing the biopesticide according to claims 6-9, characterized in that: The method comprises the following steps: fermenting Bacillus velezensis XZT106 in a fermentation medium to obtain the product.

11. Use of the Bacillus velezensis XZT106 according to claim 1, the microbial agent according to any one of claims 2 to 5, the biopesticide according to any one of claims 6 to 9, or the biopesticide prepared by the preparation method according to claim 10 in inhibiting the growth of plant pathogens, characterized in that: The plant pathogenic fungi include at least one of Phellinus noxius, Botrytis cinerea, Colletotrichum gloeosporioides, Alternaria alternata, Fusarium oxysporum, Phytophthora capsici, Fusarium solani and Colletotrichum camelliae.

12. Use of the Bacillus velezensis XZT106 according to claim 1, the microbial agent according to any one of claims 2 to 5, the biopesticide according to any one of claims 6 to 9, or the biopesticide prepared by the preparation method according to claim 10 in preparing a product for inhibiting the growth of plant pathogens, characterized in that: The plant pathogenic fungi include at least one of Phellinus noxius, Botrytis cinerea, Colletotrichum gloeosporioides, Alternaria alternata, Fusarium oxysporum, Phytophthora capsici, Fusarium solani and Colletotrichum camelliae.

13. Use of the Bacillus velezensis XZT106 according to claim 1, the microbial agent according to any one of claims 2 to 5, the biopesticide according to any one of claims 6 to 9, or the biopesticide prepared by the preparation method according to claim 10 in preparing products for preventing and controlling rubber tree brown root disease, tomato gray mold, pepper anthracnose, pepper black spot, eggplant wilt, pepper blight, pepper root rot, and tea anthracnose.

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