Bacillus, fungicide and application of bacillus in plant disease control and growth promotion

Abstract

The invention discloses bacillus, a fungicide and application of the fungicide in plant disease control and growth promotion, and relates to the technical field of biocontrol bacteria. The preservation number of the bacillus is CGMCC (China General Microbiological Culture Collection Center) No.32658 The bacillus has a broad-spectrum antibacterial effect on various plant rhizosphere disease pathogenic fungi, can effectively prevent and control eucommia ulmoides leaf gray mold, leaf blight and leaf spot disease, can promote plant growth by secreting IAA (indoleacetic acid) and can provide necessary nutritional ingredients for plant growth by dissolving inorganic phosphorus, so that the bacillus has a broad-spectrum antibacterial effect on various plant rhizosphere disease pathogenic fungi and can be used for preventing and controlling eucommia ulmoides leaf gray mold, leaf blight and leaf spot disease. The bacillus provided by the invention has the functions of broad-spectrum fungal disease resistance and growth promotion.

Description

Technical Field

[0001] The present invention relates to the technical field of biocontrol bacteria, and in particular, to a Bacillus bacterium, a bacterial agent and their applications in plant disease control and growth promotion. Background Art

[0002] The chemical components, pharmacological activities, nutrients, etc. of Eucommia ulmoides leaves are widely used in pharmaceuticals, foods, health products, and feeds, and have high development and comprehensive utilization value. However, with the increasing market demand for Eucommia ulmoides raw materials, the artificial cultivation area of Eucommia ulmoides has also been continuously expanding. Due to the over-concentration of planting plots, the fungal diseases of Eucommia ulmoides leaves have become increasingly serious, such as leaf spot, leaf blight, gray mold, etc., which seriously restricts the development of the Eucommia ulmoides industry. After the occurrence of Eucommia ulmoides leaf blight, many leaves initially show some lesions, the area continues to expand, and the disease spreads rapidly, resulting in the withering of the leaves of the whole tree. In particular, the 1-2-year-old Eucommia ulmoides seedlings are severely affected, resulting in a reduction in the yield and quality of Eucommia ulmoides leaves, which has caused huge economic losses to planting farmers and planting parks.

[0003] Currently, chemical agents are widely used to control Eucommia ulmoides leaf diseases, but chemical agent control has problems such as chemical agent residues in traditional Chinese medicines and the problem that the gray mold pathogen develops drug resistance to a variety of chemical agents. The gray mold pathogen has a wide range of hosts and high genetic variability. There are few known targeted bacterial agent controls and applications for the pathogen of Eucommia ulmoides leaf gray mold, and it is still unable to resist fungal diseases in a broad spectrum.

[0004] In view of this, the present invention is specifically proposed. Summary of the Invention

[0005] The purpose of the present invention is to provide a Bacillus bacterium, a bacterial agent and their applications in plant disease control and growth promotion to solve the above technical problems.

[0006] The present invention is implemented as follows:

[0007] In the first aspect, the present invention provides a Bacillus bacterium (Calidifontibacillus erzurumensis), which is deposited in the China General Microbiological Culture Collection Center, address: No. 3, Building 1, Beichen West Road, Chaoyang District, Beijing, deposit date: November 15, 2024, deposit number: CGMCC No. 32658.

[0008] In the second aspect, the present invention provides a bacterial agent, which includes the above-mentioned Bacillus bacterium.

[0009] In the third aspect, the present invention provides the application of the Bacillus bacterium or the above-mentioned bacterial agent in controlling plant diseases caused by fungi.

[0010] Fourthly, the present invention provides the application of Bacillus or the above-mentioned microbial agent in promoting plant growth, and the plants are selected from tomato, pepper, wheat, rice, barley, oat, corn, sorghum, millet, buckwheat, broomcorn millet, sweet potato, potato, cotton, sesame, peanut, sunflower, radish, carrot, eggplant, leek, scallion, onion, leek, spinach, celery, amaranth, lettuce, crown daisy, daylily, grape, strawberry, sugarcane, tobacco, Brassica vegetables, cucurbitaceae plants, leguminous plants, tea, cassava and Chinese herbal medicine plants;

[0011] Fifthly, the present invention provides a method for promoting plant growth, which comprises the following steps: applying the above-mentioned Bacillus or the above-mentioned microbial agent to plants.

[0012] The present invention has the following beneficial effects:

[0013] Aiming at the problems of chemical agent residues and pathogen drug resistance in the current chemical control of gray mold on Eucommia ulmoides leaves, the present invention isolates and screens a strain of Calidifontibacillus erzurumensis TD22S1 belonging to the genus Bacillus from the rhizosphere soil of Eucommia ulmoides. This strain has an effective inhibitory effect on Botrytis cinerea, the pathogen of Eucommia ulmoides leaf blight, and Alternaria alternata, the pathogen of Eucommia ulmoides leaf spot. It has a broad-spectrum antibacterial effect on pathogenic fungi of plant rhizosphere diseases such as Fusarium oxysporum f. sp. codonopsis, Fusarium oxysporum f. sp. cucumerinum, Phoma heterosclerotiorum, Fusarium tricinctum, and Fusarium solani. It can effectively prevent and control gray mold, leaf blight and leaf spot on Eucommia ulmoides leaves, and can also promote plant growth by secreting IAA and provide essential nutrients for plant growth by dissolving inorganic phosphorus. Therefore, the Bacillus provided by the present invention has both broad-spectrum antifungal disease and growth-promoting functions. The proposal of the present invention can effectively improve the yield and quality of various plants such as Eucommia ulmoides leaves, peppers, and tomatoes. Description of the Drawings

[0014] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following will briefly introduce the drawings required to be used in the embodiments. It should be understood that the following drawings only show some embodiments of the present invention, and therefore should not be regarded as limiting the scope. For those of ordinary skill in the art, other related drawings can be obtained based on these drawings without creative efforts.

[0015] Figure 1 It is a diagram of the colony morphology and phylogenetic classification results of TD22S1; A, colony morphology on LB medium; B, phylogenetic tree of the gene 16S rDNA sequence;

[0016] Figure 2Antagonistic effect diagram of biocontrol TD22S1 bacteria against Botrytis cinerea in plate confrontation. A, Front view of the antagonistic effect on 1 / 2 PDA medium; B, Back view of the PDA plate with antagonistic effect.

[0017] Figure 3 Antagonistic effect diagram of biocontrol TD22S1 bacteria against Alternaria alternata in plate confrontation. A, Front view of the antagonistic effect on 1 / 2 PDA medium; B, Back view of the PDA plate with antagonistic effect.

[0018] Figure 4 Antagonistic effect diagram of biocontrol bacteria TD22S1 against Fusarium oxysporum causing Codonopsis pilosula root rot in plate confrontation. A, Antagonistic effect diagram on 1 / 2 PDA medium; B, Colony control diagram of Fusarium oxysporum.

[0019] Figure 5 Antagonistic effect diagram of biocontrol bacteria TD22S1 against Plectosphaerella cucumerina causing cucumber fusarium wilt in plate confrontation. A, Front view of the antagonistic effect on 1 / 2 PDA medium; B, Colony control diagram of Plectosphaerella cucumerina.

[0020] Figure 6 Antagonistic effect diagram of biocontrol bacteria TD22S1 against Paraphoma ledniceana in plate confrontation. A, Front view of the antagonistic effect on 1 / 2 PDA medium; B, Colony control diagram of Paraphoma ledniceana causing Codonopsis pilosula root rot.

[0021] Figure 7 Antagonistic effect diagram of biocontrol bacteria TD22S1 against Fusarium tricinctum in plate confrontation. A, Front view of the antagonistic effect on 1 / 2 PDA medium; B, Colony control diagram of Fusarium tricinctum.

[0022] Figure 8 Antagonistic effect diagram of biocontrol bacteria TD22S1 against Fusarium solani in plate confrontation. A, Front view of the antagonistic effect on 1 / 2 PDA medium; B, Colony control diagram of Fusarium solani.

[0023] Figure 9 Detection result diagram of the IAA secretion ability of growth-promoting bacteria TD22S1.

[0024] Figure 10 Detection result diagram of the inorganic phosphorus solubilizing ability of growth-promoting bacteria TD22S1.

[0025] Figure 11Control effect diagram of biocontrol bacterium TD22S1 on Botrytis cinerea disease of pepper fruits;

[0026] Figure 12 Control effect diagram of biocontrol bacterium TD22S1 on Botrytis cinerea disease of tomato fruits;

[0027] Figure 13 Control effect diagram of biocontrol agent TD22S1 on Botrytis cinerea disease of pepper leaves;

[0028] Figure 14 Control effect diagram of biocontrol agent TD22S1 on Botrytis cinerea disease of tomato seedlings;

[0029] Figure 15 Effect diagram of TD22S1 growth-promoting bacterium agent on promoting the growth of pepper seedlings;

[0030] Figure 16 Effect diagram of TD22S1 growth-promoting bacterium agent on promoting the growth of tomato seedlings. Detailed implementation mode

[0031] Reference to the embodiments of the present invention will now be provided in detail, one or more examples of which are described below. Each example is provided by way of explanation and not limitation of the present invention. In fact, it will be apparent to those skilled in the art that various modifications and variations can be made to the present invention without departing from the scope or spirit of the present invention. For example, features described or illustrated as part of one embodiment can be used in another embodiment to yield a still further embodiment.

[0032] To make the objectives, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below. Those conditions not specified in the examples are carried out according to conventional conditions or conditions recommended by the manufacturer. The reagents or instruments not specified by the manufacturer are all conventional products that can be obtained through commercial purchase.

[0033] By isolating and identifying the pathogenic bacteria from the diseased samples, it was found that the pathogenic bacteria causing the wilt and gray mold diseases of Eucommia ulmoides leaves were Botrytis cinerea. Aiming at the problems of chemical agent residues and pathogen drug resistance in the current chemical control of gray mold disease of Eucommia ulmoides leaves, a strain of Calidifontibacillus erzurumensis TD22S1 bacterium belonging to the genus Bacillus was isolated and screened from the rhizosphere soil of Eucommia ulmoides. This strain has effective inhibitory effects on the pathogenic Botrytis cinerea of Eucommia ulmoides leaf blight and the pathogenic Alternaria alternata of Eucommia ulmoides leaf spot, and can effectively prevent and control gray mold disease, leaf blight and leaf spot of Eucommia ulmoides leaves, and has both broad-spectrum antifungal disease and growth-promoting functions.

[0034] In a first aspect, the present invention provides a Bacillus (Calidifontibacillus erzurumensis), which is deposited in the China General Microbiological Culture Collection Center, address: No. 3, Yard 1, Beichen West Road, Chaoyang District, Beijing, deposit date: November 15, 2024, deposit number: CGMCC No. 32658. The name of the biological material submitted for deposit is TD22S1, and the proposed taxonomic name is Calidifontibacillus erzurumensis. The identification result is viable.

[0035] There are studies showing that plant growth-promoting rhizobacteria (PGPR) are beneficial bacteria that can stably survive in the rhizosphere or on the root surface and can secrete various secondary metabolites to directly or indirectly promote plant growth and prevent and control diseases. The promotion of plant growth by PGPR is mainly reflected in promoting plant growth by secreting secondary metabolites such as the plant growth hormone 3-indoleacetic acid (IAA). Therefore, the TD22S1 strain also belongs to plant growth-promoting rhizobacteria and has both biocontrol and growth-promoting functions of promoting plant growth and preventing plant diseases.

[0036] In a second aspect, the present invention provides a microbial agent, which comprises the above-mentioned Bacillus. The microbial agent is, for example, prepared by diluting the fermentation product.

[0037] It includes, but is not limited to, being obtained by solid fermentation or liquid fermentation of the above-mentioned Bacillus. The microbial agent includes, but is not limited to, at least one of concentrates, pastes, dried products, liquid products, dilutions, and crushed products of Bacillus. The dried products include, but are not limited to, spray-dried products, freeze-dried products, vacuum-dried products, drum-dried products, etc.

[0038] In a third aspect, the present invention provides the application of the Bacillus or the above-mentioned microbial agent in preventing and controlling plant diseases caused by fungi.

[0039] The present invention has a broad-spectrum antibacterial effect on pathogenic fungi of plant rhizosphere diseases such as Botrytis cinerea, Alternaria alternata, Fusarium oxysporum f. sp. codonopsis, Fusarium oxysporum f. sp. cucumerinum, Phomopsis heterosclerotiorum, Fusarium tricinctum, and Fusarium solani.

[0040] In a preferred embodiment of the application of the present invention, the fungal disease is a plant disease caused by at least one selected from Botrytis cinerea, Alternaria alternata, Fusarium oxysporum, Plectosphaerella cucumerina, Paraphoma ledniceana, Fusarium tricinctum, and Fusarium solani.

[0041] In a preferred embodiment of the application of the present invention, the plants are selected from tomato, pepper, wheat, rice, barley, oats, corn, sorghum, millet, buckwheat, broomcorn millet, sweet potato, potato, cotton, sesame, peanut, sunflower, radish, carrot, eggplant, leek, green onion, onion, leek, spinach, celery, amaranth, lettuce, crown daisy, daylily, grape, strawberry, sugarcane, tobacco, cruciferous vegetables, cucurbitaceae plants, leguminous plants, tea, cassava, and Chinese herbal medicine plants;

[0042] In a preferred embodiment of the application of the present invention, the Chinese herbal medicine plants are selected from Codonopsis pilosula, Eucommia ulmoides, Scutellaria baicalensis, Cannabis sativa, Isatis indigotica, Astragalus membranaceus, Lonicera japonica, Forsythia suspensa, Phellodendron amurense, Coptis chinensis, Polygonum cuspidatum, Gardenia jasminoides, Paris polyphylla, Bupleurum chinense, Isatis indigotica, Taraxacum mongolicum, Lycium chinense, Anemarrhena asphodeloides, Rehmannia glutinosa, Scrophularia ningpoensis, Sterculia lychnophora, Sargentodoxa cuneata, Paeonia veitchii, Pulsatilla chinensis, and Paeonia suffruticosa.

[0043] In a preferred embodiment of the application of the present invention, the Bacillus or the microbial agent is used for preventing and controlling plant gray mold disease, plant leaf spot disease, or plant leaf blight caused by fungi;

[0044] In a preferred embodiment of the application of the present invention, the Bacillus or the microbial agent is used for preventing and controlling plant gray mold disease or plant leaf blight caused by Botrytis cinerea, and the Bacillus or the microbial agent is used for preventing and controlling plant leaf spot disease caused by Alternaria alternata.

[0045] Fourthly, the present invention provides the application of the Bacillus or the above-mentioned microbial agent in promoting plant growth, and the plants are selected from tomato, pepper, wheat, rice, barley, oats, corn, sorghum, millet, buckwheat, broomcorn millet, sweet potato, potato, cotton, sesame, peanut, sunflower, radish, carrot, eggplant, leek, green onion, onion, leek, spinach, celery, amaranth, lettuce, crown daisy, daylily, grape, strawberry, sugarcane, tobacco, cruciferous vegetables, cucurbitaceae plants, leguminous plants, tea, cassava, and Chinese herbal medicine plants.

[0046] The strain Calidifontibacillus erzurumensis TD22S1 promotes plant growth by secreting IAA and provides essential nutrients for plant growth by dissolving inorganic phosphorus. Therefore, the strain Calidifontibacillus erzurumensis TD22S1 has both biocontrol and growth-promoting functions of promoting plant growth and preventing plant diseases.

[0047] In a preferred embodiment of the application of the present invention, the Chinese herbal medicine plants are selected from Codonopsis pilosula, Eucommia ulmoides, Scutellaria baicalensis, Cannabis sativa, Isatis tinctoria, Astragalus membranaceus, Lonicera japonica, Forsythia suspensa, Phellodendron amurense, Coptis chinensis, Polygonum cuspidatum, Gardenia jasminoides, Paris polyphylla, Bupleurum chinense, Isatis tinctoria, Taraxacum mongolicum, Lycium chinense, Anemarrhena asphodeloides, Rehmannia glutinosa, Scrophularia ningpoensis, Sterculia lychnophora, Sargentodoxa cuneata, Paeonia lactiflora, and Paeonia suffruticosa.

[0048] In a preferred embodiment of the application of the present invention, the application includes the following application methods:

[0049] (1) Bacillus secretes IAA;

[0050] (2) Bacillus dissolves inorganic phosphorus.

[0051] In a preferred embodiment of the application of the present invention, the application includes at least one of the following application methods:

[0052] (1) Used as a root drench;

[0053] (2) Used as a seed soaking agent;

[0054] (3) Used as a foliar spray.

[0055] In a preferred embodiment of the application of the present invention, promoting plant growth includes at least one of the following applications:

[0056] (1) Increasing the fresh weight of plants;

[0057] (2) Increasing the dry weight of plants;

[0058] (3) Increasing the plant height.

[0059] Fresh weight refers to the weight of an organism or cell in its natural state, including all the water and other components inside the cell. Dry weight refers to the weight of an organism or cell after removing all free water.

[0060] In a preferred embodiment of the application of the present invention, the use concentration of Bacillus is 1×10 5 -1×10 8 CFU / mL. The actual use concentration can be adjusted as needed, such as dilution or concentration. For example, the use concentration is 1×10 5CFU / mL, 2×10 5 CFU / mL, 3×10 5 CFU / mL, 4×10 5 CFU / mL, 5×10 5 CFU / mL, 6×10 5 CFU / mL, 7×10 5 CFU / mL, 8×10 5 CFU / mL, 9×10 5 CFU / mL, 1×10 6 CFU / mL, 2×10 6 CFU / mL, 3×10 6 CFU / mL, 4×10 6 CFU / mL, 5×10 6 CFU / mL, 8×10 6 CFU / mL, 9×10 6 CFU / mL, 1×10 7 CFU / mL, 4×10 7 CFU / mL, 5×10 7 CFU / mL, 1×10 8 CFU / mL.

[0061] In a preferred embodiment of the application of the present invention, at least one of a surfactant, a binder, a stabilizer, a pH regulator, a protective agent, an excipient, a disintegrant, a lubricant, a fragrance, a preservative, a suspending agent, a dispersing agent, and a diluent is further added to the root irrigation agent, the seed soaking agent, or the foliar spraying agent.

[0062] Examples include: surfactants such as Tween 20, Tween 80, etc.; pH regulators such as disodium hydrogen phosphate, dipotassium hydrogen phosphate, etc.; excipients such as sucrose, starch, mannitol, sorbitol, lactose, glucose, cellulose, talc, calcium phosphate, calcium carbonate; binders such as cellulose, methylcellulose, hydroxypropylcellulose, polypropylpyrrolidone, gelatin, gum arabic, polyethylene glycol, sucrose, starch; disintegrants such as starch, hydrolyzed starch, carboxymethylcellulose, calcium carboxymethylcellulose, hydroxypropyl starch, sodium glycol starch, sodium bicarbonate, calcium phosphate, calcium citrate; lubricants such as magnesium stearate, talc, sodium lauryl sulfate; fragrances such as citric acid, menthol, glycine, orange powder; preservatives such as sodium benzoate, sodium bisulfite, parabens (such as methyl paraben, ethyl paraben, propyl paraben, butyl paraben); stabilizers such as citric acid, sodium citrate, acetic acid and polycarboxylic acids from the titriplex series such as diethylenetriaminepentaacetic acid (DTPA); suspending agents such as methylcellulose, polyvinylpyrrolidone, aluminum stearate; dispersants; diluents such as water, organic solvents; waxes, fats and oils such as beeswax, cocoa butter; polyethylene glycol; white petrolatum, etc.

[0063] When used as a root irrigation agent, the timing of root irrigation includes but is not limited to the seedling stage, maturity stage, etc. When used as a seed soaking agent, it includes but is not limited to soaking the seeds of plants and then sowing. In an alternative embodiment, Bacillus can be attached to the surface of the seeds as a component of the seed coating, for example, as a filler in the seed coating. When used as a foliar spraying bacterium, a leaf spraying agent containing Bacillus can be sprayed onto the leaf surface or fruit surface of the target plant.

[0064] In a fifth aspect, the present invention provides a method for promoting plant growth, which includes the following steps: applying the above-mentioned Bacillus or the above-mentioned bacterial agent to plants.

[0065] In a preferred embodiment of the application of the present invention, Bacillus is used for root irrigation, seed soaking, or spraying on the leaves, stems or fruits of plants.

[0066] The Bacillus or the above-mentioned bacterial agent provided by the present invention can increase the plant height, fresh weight and dry weight of plant seedlings, and can effectively promote the growth of plant seedlings. Especially for peppers and tomatoes.

[0067] The plants are selected from tomatoes, peppers, wheat, rice, barley, oats, corn, sorghum, millet, buckwheat, proso millet, sweet potatoes, potatoes, cotton, sesame, peanuts, sunflowers, radishes, carrots, eggplants, leeks, green onions, onions, leeks, spinach, celery, amaranth, lettuce, crown daisy, daylilies, grapes, strawberries, sugarcane, tobacco, Brassica vegetables, cucurbitaceae plants, leguminous plants, tea, cassava and Chinese herbal medicine plants;

[0068] In a preferred embodiment of the application of the present invention, the Chinese herbal plants are selected from Codonopsis pilosula, Eucommia ulmoides, Scutellaria baicalensis, Cannabis sativa, Isatis tinctoria, Astragalus membranaceus, Lonicera japonica, Forsythia suspensa, Phellodendron amurense, Coptis chinensis, Polygonum cuspidatum, Gardenia jasminoides, Paris polyphylla, Bupleurum chinense, Isatis tinctoria, Taraxacum mongolicum, Lycium chinense, Anemarrhena asphodeloides, Rehmannia glutinosa, Scrophularia ningpoensis, Sterculia lychnophora, Sargentodoxa cuneata, Paeonia veitchii, Pulsatilla chinensis, and Paeonia suffruticosa.

[0069] In a preferred embodiment of the application of the present invention, Bacillus is used for root irrigation, seed soaking of plants, or spraying on the leaves, stems or fruits of plants.

[0070] In a preferred embodiment of the application of the present invention, the use concentration of Bacillus is 1×10 5 -1×10 8 CFU / mL. The actual use concentration can be adjusted according to needs, such as dilution or concentration. For example, the use concentrations are 1×10 5 CFU / mL, 2×10 5 CFU / mL, 3×10 5 CFU / mL, 4×10 5 CFU / mL, 5×10 5 CFU / mL, 6×10 5 CFU / mL, 7×10 5 CFU / mL, 8×10 5 CFU / mL, 9×10 5 CFU / mL, 1×10 6 CFU / mL, 2×10 6 CFU / mL, 3×10 6 CFU / mL, 4×10 6 CFU / mL, 5×10 6 CFU / mL, 8×10 6 CFU / mL, 9×10 6 CFU / mL, 1×10 7 CFU / mL, 4×10 7 CFU / mL, 5×10 7 CFU / mL, 1×10 8 CFU / mL.

[0071] The features and properties of the present invention will be further described in detail below in conjunction with examples.

[0072] Example 1

[0073] In this example, the isolation and identification of Bacillus were carried out.

[0074] 1. Sample source

[0075] In 2021, disease investigations and samplings were carried out at Jinjiahe (33°20'01.6"N, 105°59'10.9"E), Lueyang County, Hanzhong City, the main Eucommia ulmoides Oliv. production area in China. Five diseased plants and their leaves, five healthy seedlings and five rhizosphere soil samples were collected in the Eucommia ulmoides Oliv. planting area. The areas where the diseased plants were located were all infected, and the healthy samples were taken from adjacent areas. The method for collecting rhizosphere soil was to shake off the soil on the root surface and gently brush it with a disinfected toothbrush. The samples were transported back to the laboratory in a sampling box equipped with ice packs on the same day and stored in a 4°C refrigerator, and then the fungal pathogens and antagonistic bacteria were isolated immediately.

[0076] 2. Sources of the pathogens Botrytis cinerea Pers. and Alternaria alternata (Fr.) Keissl. on Eucommia ulmoides Oliv. leaves.

[0077] The pathogens Botrytis cinerea Pers. causing Eucommia ulmoides Oliv. leaf blight and Alternaria alternata (Fr.) Keissl. causing Eucommia ulmoides Oliv. leaf spot were both isolated from the diseased leaves of the above-mentioned Eucommia ulmoides Oliv. plants with leaf blight, from three diseased leaves of Eucommia ulmoides Oliv. seedlings showing typical leaf blight and leaf spot symptoms. At the junction of the diseased area and the healthy area, the leaf samples were surface-sterilized respectively, that is, rinsed twice with sterile water, soaked in 75% absolute ethanol for 30 s, rinsed twice with sterile water, soaked in 3% sodium hypochlorite for 5 minutes, and rinsed three times with sterile water. The surface-sterilized sample materials were cut into small pieces (each about 1×0.5 inches in size) with a sterile scalpel. Every three small pieces were placed on Rose Bengal agar medium, which was prepared by adding 5 g peptone, 10 g glucose, 1 g potassium dihydrogen phosphate, 0.5 g magnesium sulfate, 0.033 g Rose Bengal, 0.1 g chloramphenicol and 15 g agar to every 1 liter of ultrapure water. After culturing at 25°C for 5 - 7 days, the mycelium was taken from the edge of the primary colony and placed on a PDA plate for further purification. After obtaining the purified fungi, through morphological and molecular biological identification, and pathogenicity re-inoculation experiments for verification, it was obtained that the pathogen causing Eucommia ulmoides Oliv. leaf blight was Botrytis cinerea Pers., and the pathogen causing Eucommia ulmoides Oliv. leaf spot was Alternaria alternata (Fr.) Keissl. Both Botrytis cinerea Pers. and Alternaria alternata (Fr.) Keissl. were preserved in this laboratory.

[0078] 3. Isolation and culture of antagonistic bacteria in the rhizosphere of Eucommia ulmoides Oliv.

[0079] To isolate antagonistic bacteria against Botrytis cinerea Pers. on Eucommia ulmoides Oliv. leaf blight, rhizosphere soil samples were collected from healthy 2-year-old trees in the adjacent planting area. Five rhizosphere soil samples were mixed with soil at four dilution gradients (10 2 , 10 3 , 10 4 ) and cultured in TSB (17 g tryptone, 5 g sodium chloride, 3 g soy peptone, 2.5 g dipotassium hydrogen phosphate, 2.5 g glucose, adding 15 g agar powder to every 1 liter of ultrapure water, making up to 1 L, adjusting the pH to 7.3) medium at 30°C for 2 - 5 days. After three purification processes, the duplicates were removed according to the morphology and characteristics of the newly grown colonies. Except for the strains that could not be subcultured further, the strains were all stored in 40% glycerol at -80°C.

[0080] Among the numerous bacteria isolated from the rhizosphere of Eucommia ulmoides, antagonistic bacteria against Botrytis cinerea and Alternaria alternata of Eucommia ulmoides were screened out. The antagonistic bacterial strains were inoculated into liquid LB medium and cultured with shaking for 48 hours. The precipitated bacteria were centrifuged at 5000 rpm for 5 minutes and resuspended with an equal volume of sterile water. After the pathogenic fungus Botrytis cinerea grew on the 1 / 2 PDA plate for 10 days, a small amount of mycelium was inoculated in the center of a new 1 / 2 PDA plate. Then, 5 μL of the bacterial suspension was dropped at each of the four symmetric points of the cross. Sterile water was used as a control. The colony radii of Botrytis cinerea and Alternaria alternata on these antagonistic assay plates were measured after culturing at 25 °C for 5 days using ImageJ v.1.53a (NIH) software. The fungal growth inhibition rate (PFGI) was calculated using the formula: PFGI = (R1 - R2) / R1 * 100%. R1 represents the average diameter of the mycelium in the blank test, and R2 is the diameter of the inhibited bacteria.

[0081] The antagonistic effect of the biocontrol TD22S1 strain against Botrytis cinerea in the plate confrontation is shown in Figure 2 as follows. Figure 2 Figure A in

[0082] is the front view of the antagonistic effect on the 1 / 2 PDA medium; Figure B is the back view of the PDA plate with the antagonistic effect. As can be seen from the results, the screened biocontrol TD22S1 strain has a high antagonistic effect against Botrytis cinerea. Figure 3 as follows. Figure 3 Figure A in

[0083] The present invention also provides a method for culturing the above TD22S1 bacterial agent, including the following steps: After preparing a single colony of Calidifontibacillus erzurumensis TD22S1 into a seed suspension, it is inoculated into LB liquid medium and cultured with shaking at 30 °C and 200 r / min for 24 - 48 hours, and the inoculation concentration is 10 6 -10 8 CFU / mL.

[0084] Using the above TD22S1 bacterial agent or bacterial liquid as the active ingredient, in the plate confrontation co-culture test on PDA, the growth inhibition rates against Botrytis cinerea, the pathogen of Eucommia ulmoides leaf blight, and Alternaria alternata, the pathogen of Eucommia ulmoides leaf spot, are 44.36% and 67.25% respectively.

[0085] 4. Observation of the colony morphological characteristics of TD22S1

[0086] Streak a single colony of TD22S1 on LB agar medium (10 g sodium chloride, 10 g peptone, 5 g yeast extract, made up to 1 L with distilled water). After sealing with parafilm, place it in an incubator at 30 °C for 48 h and then take it out to observe the characteristics of the single colony such as its morphology, color, and texture. The observation results show that the single colony of TD22S1 on LB medium is white, with a rough surface and irregular edges, as specifically shown in Figure 1 Figure A below.

[0087] 5. 16S rDNA gene sequence and phylogenetic identification of TD22S1 bacteria

[0088] Pick a single colony of the purified TD22S1 bacterial strain and culture it overnight in LB liquid medium at 30 °C with a rotation speed of 180 rpm. After centrifuging at 10000 rpm for 2 minutes, collect the bacterial cells. Use the EZ-10 Column Bacterial Genomic DNA Extraction Kit (Shanghai Sangon Biological Engineering Technology & Services Co., Ltd.) to extract the genomic DNA of the bacterial cells of this strain according to the steps in the instruction manual. Using the obtained DNA as a template, perform PCR amplification with the universal primers 27F (5’-AGAGTTTGATCCTGGCTCAG-3’) and 1492R (5’-GGTTACCTTGTTACGACTT-3’) for the bacterial 16S rDNA gene. The amplification conditions are 93 °C for 4 minutes; 30 cycles: 94 °C for 30 seconds, 48 °C for 15 seconds, 72 °C for 1 minute; 72 °C for 10 minutes. Detect the amplification quality of the PCR product by 1% agarose gel electrophoresis. Subsequently, send the product to Shanghai Sangon Biological Engineering Co., Ltd. for Sanger bidirectional sequencing.

[0089] Use Seqman software to splice the gene sequences obtained from bidirectional sequencing. The 16S rDNA nucleotide sequence of the TD22S1 bacterial strain obtained is shown as SEQ ID NO.1, with a length of 1394 bp. Upload the spliced sequence to the NCBI database and perform Blastn alignment similarity to obtain related sequences. Align these sequences using Align and then use the Mega11 software. After that, construct a phylogenetic tree using the Neighbor-joining method. The results are as shown in Figure 1As shown in B. The 16S rDNA related sequence of strain TD22S1 is Calidifontibacillus erzurumensis (NR_180225), with a similarity of 100%. This strain Calidifontibacillus erzurumensis TD22S1 was deposited on January 15, 2024 at the China General Microbiological Culture Collection Center (CGMCC), deposit address: Institute of Microbiology, Chinese Academy of Sciences, No. 3, Yard 1, Beichen West Road, Chaoyang District, Beijing. The deposit name is Calidifontibacillus erzurumensis TD22S1, and the deposit number is: CGMCC No. 32658.

[0090] The following is the result of sequencing sequence splicing (as shown in SEQ ID NO.1):

[0091]

[0092] Example 2

[0093] This example provides an experiment on the inhibition of mycelial growth of Fusarium oxysporum, Plectosphaerella cucumerina, Paraphomaledniceana, Fusarium tricinctum, and Fusarium solani, which cause root rot in Codonopsis pilosula, by TD22S1 bacteria. Using the TD22S1 bacterial agent or bacterial solution screened in Example 1 above as the active ingredient, a co-culture confrontation test was carried out with the above-mentioned various pathogenic bacteria on a PDA plate.

[0094] The specific steps are as follows:

[0095] 1. Source of pathogenic bacteria

[0096] Fusarium oxysporum was isolated from the roots of Codonopsis pilosula with black root rot (published in the literature [First report of root rot caused by the Fusarium oxysporum species complex on Codonopsis pilosula in China, Zhao Xia et al., Plant Disease. 105.11: 3742. 2021]), Plectosphaerella cucumerina and Paraphomaledniceana were isolated from the diseased roots of Codonopsis pilosula (published in the literature [Continuous monoculture alters the fungal community and accumulates potential pathogenic strains in the rhizosphere of Codonopsis pilosula. Zhao Xia et al., Phytobiomes Journal: PBIOMES - 11, 2024]), and Fusarium tricinctum and Fusarium solani preserved in this laboratory.

[0097] 2. Test on the inhibitory activity of the biocontrol bacterium TD22S1 against multiple pathogenic fungi of Codonopsis pilosula.

[0098] The biocontrol bacterium TD22S1 strain was inoculated into liquid LB medium and cultured with shaking for 48 hours. The precipitated bacterial cells were centrifuged at 5000 rpm for 5 minutes and resuspended with an equal volume of sterile water. After the five pathogenic fungi, Fusarium oxysporum causing Codonopsis root rot, Fusarium oxysporum f. sp. cucumerinum causing Codonopsis root rot, Phomopsis heterocerus causing Codonopsis root rot, Fusarium tricinctum, and Fusarium solani, grew on 1 / 2 PDA plates for 3 days and 7 days respectively, a small amount of mycelia was inoculated in the center of a new 1 / 2 PDA plate. Then, 5 μL of the TD22S1 bacterial liquid was added dropwise to each of the four symmetrically spaced points of the cross. Sterile water was used as a control. These antagonistic assay plates were cultured at 25 °C for 6 days, 9 days, 7 days, and 30 days respectively and observed. The results showed that the biocontrol bacterium TD22S1 had an antibacterial effect on Fusarium oxysporum causing Codonopsis root rot ( Figure 4 ), Fusarium oxysporum f. sp. cucumerinum causing Codonopsis root rot ( Figure 5 ), Phomopsis heterocerus causing Codonopsis root rot ( Figure 6 ), Fusarium tricinctum ( Figure 7 ), and Fusarium solani ( Figure 8 ).

[0099] Example 3

[0100] In this example, a growth-promoting experiment was conducted on the TD22S1 strain. Specifically, a plant growth-promoting bactericide was provided, with the above TD22S1 bactericide or bacterial liquid as the active ingredient, and it was found that the TD22S1 bactericide or bacterial liquid had the potential ability to secrete IAA and dissolve organic phosphorus to promote plant growth.

[0101] 1. Determination of the ability to secrete IAA.

[0102] A single colony of TD22S1 was picked into 1 mL of LB liquid medium and cultured with shaking at 180 rpm at 30 °C for 24 hours for activation. 10 μL of the activated TD22S1 bacterial liquid was aspirated and added to LB liquid medium containing 200 mg / L of L-tryptophan, and incubated at 180 rpm in a shaker at 30 °C for 4 days. Then, 50 μL of the bacterial liquid was dropped into the depression of a white ceramic plate, and then 50 μL of Salkowski colorimetric solution (Salkowski colorimetric solution preparation: 50 mL of 30% HClO4, 1 mL of 0.5 mol / L FeCl3) was added for color reaction. 50 μL of colorimetric solution containing 50 mg / L IAA was used as a positive control. 50 μL of the uninoculated liquid LB medium was used as a negative control. The ceramic plate was placed in the dark for color development for 30 minutes. If the color turned red, it indicated that the strain had the ability to produce IAA.

[0103] The detection results were as Figure 9 shown. The reaction solution inoculated with the growth-promoting bacterium TD22S1 showed an obvious red color, indicating that the TD22S1 bacterium had the ability to produce IAA.

[0104] 2. Determination of the ability to dissolve inorganic phosphorus.

[0105] A single colony TD22S1 was picked and cultured in LB liquid medium at 180 rpm and shaken overnight at 30 °C for activation. 10 μL of the above-activated RD212 bacterial solution was aspirated and dropped on the surface of a solid inorganic phosphorus medium (the inorganic phosphorus medium was prepared as follows: 10 g of glucose, 0.5 g of ammonium sulfate, 0.3 g of magnesium sulfate heptahydrate, 0.03 g of manganese sulfate tetrahydrate, 0.3 g of potassium chloride, 0.03 g of ferrous sulfate heptahydrate, 0.3 g of sodium chloride, 10 g of calcium phosphate, 15 g of agar powder, 1 L of distilled water, pH = 7.0). After static culture at 30 °C for 2 to 4 days, it was observed and recorded whether there was a clear halo around the colony to determine whether the strain could dissolve inorganic phosphorus.

[0106] The test results are as Figure 10 shown. There was an obvious clear halo around the TD22S1 colony, indicating that the growth-promoting bacterium TD22S1 has the ability to dissolve inorganic phosphorus.

[0107] Example 4

[0108] In this example, an experiment on preventing and controlling gray mold diseases of pepper and tomato fruits with the TD22S1 bacterial agent was carried out. Spraying the above broad-spectrum antibacterial agent TD22S1 and the fungal plugs inoculated with Botrytis cinerea on the wounds of pepper and tomato fruits could effectively reduce the incidence of gray mold diseases of pepper and tomato fruits.

[0109] 1. Preparation of the TD22S1 bacterial agent.

[0110] The above-activated TD22S1 bacterial solution in the example was transferred to 50 mL of liquid LB medium for activation and cultured in a shaker at 37 °C at 180 rpm for 48 hours. The cultured bacterial solution was centrifuged at 8000 g for 5 min, the supernatant was discarded, and the precipitated bacteria were collected. Then, it was resuspended with 50 mL of sterile water to prepare the TD22S1 bacterial agent. The viable bacteria count was detected under a microscope to be 1×10 6 -1×10 7 CFU / mL.

[0111] 2. Application of preventing and controlling gray mold disease of pepper fruits.

[0112] Soak the pepper fruits in 1% (v / v) sodium hypochlorite solution for 2 minutes, and then rinse them 3 times in sterile distilled water. Then spray the above-mentioned biocontrol bacterial solution of TD22S1 with a sterilized sterile sprayer, spraying 0.3 mL on each pepper fruit in the experimental group. Spray 0.3 mL of sterile water in the control group. After air-drying, make vertical wounds at the tip, center, and bottom of each pepper fruit with a sterile pipette tip. Punch a disc with a diameter of about 3 mm from the Botrytis cinerea mycelium cultured on PDA medium for 14 days, and attach the mycelium facing downwards to the wound site. Place the treated fruits in a sterilized plastic box and place them in an incubator at about 24 °C with a relative humidity of 100% for 5 days, observe and record the results. And count the number of diseased sites on the inoculated parts of the pepper fruit surface, and use the calculation formula of the number of diseased sites / the total number of inoculated sites × 100% = incidence rate (%) to quantitatively analyze the control effect of the biocontrol TD22S1 bactericide on pepper gray mold.

[0113] According to Figure 11 (pepper fruits) and Figure 12 (tomato fruits) The results show that the biocontrol bactericide TD22S1 can inhibit the gray mold diseases of pepper fruits and tomato fruits. Table 1 shows the statistical results of the incidence rate, indicating that compared with the control, the incidence rates of gray mold on pepper fruits and tomato fruits are significantly reduced after inoculation with the biocontrol bactericide TD22S1. Compared with 74.11% of the control group for pepper fruits, the incidence rate after spraying the biocontrol bactericide TD22S1 decreased to 31.00%, and the relative control effect reached 58.17%; compared with 83.54% of the control group for tomato fruits, the incidence rate after spraying the biocontrol bactericide TD22S1 decreased to 23.16%, and the relative control effect reached 72.28%. The above results indicate that the biocontrol bactericide TD22S1 has a good application effect in inhibiting gray mold on pepper fruits and tomato fruits, and can effectively control gray mold on pepper fruits and tomato fruits.

[0114] Table 1. Control effect of biocontrol bactericide TD22S1 on gray mold of pepper fruits and tomato fruits

[0115]

[0116] Example 5

[0117] This example provides a control method for gray mold diseases on the leaves of pepper and tomato seedlings. It includes spraying the above-mentioned biocontrol bactericide TD22S1 on the pepper and tomato leaves, and inoculating Botrytis plugs on pepper seedlings and spraying spore suspension on tomato seedlings, which has a good application effect in inhibiting gray mold on pepper and tomato plants.

[0118] The specific steps are as follows:

[0119] 1. Preparation of pathogen spore suspension.

[0120] Add 20 mL of sterile water to a PDA plate with Botrytis cinerea cultured for 30 days, gently brush it with a sterile toothbrush, and filter the mixture of spores and hyphae through four layers of sterile cotton gauze to obtain a spore suspension. Detect it with a microscope and adjust the concentration to 1×10 5 -1×10 6 spores / mL to prepare a pathogen spore suspension.

[0121] 2. Application of biological control of Botrytis cinerea on pepper and tomato seedlings.

[0122] Spray the above TD22S1 biocontrol bacterial solution on pepper and tomato seedlings respectively. Each seedling in the experimental group is sprayed with 0.5 mL (containing 0.2% Tween 20). Each seedling in the control group is sprayed with 0.3 mL of sterile water (containing 0.2% Tween 20). After the water stains on the pepper leaf surface are dried, cut a disk with a diameter of about 3 mm from the Botrytis cinerea hyphae cultured on the PDA medium for 14 days, and stick the hyphae downward on the surface of the pepper leaf. After the water stains on the tomato leaf surface are dried, spray the above pathogen spore suspension on the tomato leaf surface. Each seedling is sprayed with 0.5 mL of spore suspension and left standing until the water stains on the leaf surface are dried. Place the treated pepper and tomato seedlings in a greenhouse at about 24°C with a relative humidity of over 70%, record the wilting of the seedling leaves, and conduct statistics on the leaf incidence rate.

[0123] According to Figure 13 and Figure 14 The results show that the TD22S1 biocontrol agent can inhibit Botrytis cinerea on pepper and tomato leaves. According to the statistical results of the incidence rate in Table 2, compared with the control, the incidence rate of Botrytis cinerea on pepper and tomato after inoculation with the TD22S1 biocontrol agent is significantly reduced. The incidence rate of Botrytis cinerea on pepper leaves decreased to 41.50% after spraying the TD22S1 biocontrol agent, compared with 67.01% in the control group, and the relative control effect reached 38.07%; the incidence rate of Botrytis cinerea on tomato leaves decreased to 64.00% after spraying the TD22S1 biocontrol agent, compared with 88.83% in the control group, and the relative control effect reached 27.95%. The above results indicate that the TD22S1 biocontrol agent has a good application effect on inhibiting Botrytis cinerea on the leaves of pepper and tomato plants, and can effectively control Botrytis cinerea on pepper and tomato plants.

[0124] Table 2. Control effect of TD22S1 biocontrol agent on Botrytis cinerea of pepper and tomato leaves

[0125]

[0126] Example 6

[0127] This embodiment also provides a method for promoting the growth of pepper and tomato seedlings, which includes inoculating the bacterial agent TD22S1 into the soil at the roots of potted pepper and tomato seedlings, increasing the plant height, fresh weight and dry weight of pepper and tomato seedlings, and effectively promoting the growth of pepper and tomato seedlings.

[0128] Use seed sowing, thin out or fill in seedlings after emergence to ensure that there are 3 seedlings in each hole (9 cm × 9 cm) of the seedling tray. Conduct the above inoculation treatment of the TD22S1 bacterial agent on 30-day-old pepper and tomato seedlings, and adopt the root irrigation inoculation method. In the experimental group, 1 mL of the TD22S1 bacterial agent was inoculated at the rhizosphere of each seedling, and the second inoculation of the bacterial agent was carried out after one week, with tap water inoculation as the control group. Observe and record the growth of pepper and tomato 30 days after inoculation, and count the plant height and fresh weight of each seedling. After the harvested seedlings are air-dried in an envelope bag at room temperature for 14 days, the dry weight is measured. The plant height is measured using ImageJ software, and data statistical analysis is carried out using spss 18 software. The significance of the differences in various parameters (fresh weight, dry weight, plant height) between the inoculated TD22S1 and the control group is tested by one-way ANOVA (Duncan method, P < 0.05).

[0129] According to Figure 15 (pepper) and Figure 16 (tomato) results show that the TD22S1 growth-promoting bacterial agent can significantly increase the growth of pepper and tomato. According to the statistics of the plant height, fresh weight and dry weight of pepper and tomato in Table 3, compared with the average plant height of 13.65 cm and 24.70 cm in the control group, the average plant height increased to 15.35 cm and 32.27 cm after inoculating the TD22S1 growth-promoting bacterial agent; compared with the average fresh weight of 1.02 g and 3.14 g in the control group, the average fresh weight increased to 1.50 g and 4.18 g after inoculating the TD22S1 growth-promoting bacterial agent; compared with the average dry weight of 0.10 g and 0.28 g in the control group, the average dry weight increased to 0.15 g and 0.40 g after inoculating the TD22S1 growth-promoting bacterial agent. The above results show that the TD22S1 growth-promoting bacterial agent has a good application effect on promoting the growth and development of pepper and tomato.

[0130] Table 3. The application of the TD22S1 growth-promoting bacterial agent increases the plant height, fresh weight and dry weight of tomato seedlings.

[0131]

[0132]

[0133] Note: The data in the table are the average value ± standard error of each seedling. Different letters indicate significant differences at the P < 0.05 level in the Duncan test.

[0134] A biocontrol bacterium TD22S1 screened from the rhizosphere soil of Eucommia ulmoides, identified as Calidifontibacillus erzurumensis through morphological and molecular biological species identification. On the one hand, this strain has strong abilities of secreting IAA and dissolving inorganic phosphorus. On the other hand, this strain has effective inhibitory effects on the mycelial growth of the pathogenic fungus Botrytis cinerea of Eucommia ulmoides leaf blight and Alternaria alternata of Eucommia ulmoides leaf spot, and has broad-spectrum antibacterial effects on pathogenic fungi of plant rhizosphere diseases such as Fusarium oxysporum of Codonopsis pilosula root rot, Fusarium oxysporum f. sp. cucumerinum of Codonopsis pilosula root rot, Phomopsis heterocaulis of Codonopsis pilosula root rot, Fusarium tricinctum, and Fusarium solani. The TD22S1 strain promotes plant growth by secreting IAA and provides essential nutrients for plant growth by dissolving inorganic phosphorus. Therefore, the TD22S1 strain has both biocontrol and growth-promoting functions of promoting plant growth and controlling plant diseases.

[0135] The Calidifontibacillus erzurumensis TD22S1 bacterium, bactericide and application provided by the present invention can effectively control gray mold of pepper fruits, tomato fruits, pepper leaves and tomato leaves, and have good application prospects for controlling plant diseases.

[0136] In addition, the Calidifontibacillus erzurumensis TD22S1 bacterium, bactericide and application provided by the present invention can effectively promote the growth and development of various plants such as pepper and tomato, and can improve the yield and quality of various plants.

[0137] The above are only the preferred embodiments of the present invention and are not used to limit the present invention. For those skilled in the art, the present invention can have various changes and modifications. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A Bacillus (Calidifontibacillus erzurumensis), characterized in that, It is preserved in the General Microbiological Center of the China General Microbiological Culture Collection Center, Address: No. 3, Yard 1, Beichen West Road, Chaoyang District, Beijing, Preservation Date: November 15, 2024, Preservation Number: CGMCC No. 32658.

2. A bacterial agent, characterized in that, It includes the Bacillus sp. described in claim 1.

3. Use of the Bacillus sp. described in claim 1 or the microbial agent described in claim 2 in controlling plant diseases caused by fungi.

4. The application according to claim 3, characterized in that The fungal diseases are selected from plant diseases caused by at least one of Botrytis cinerea, Alternaria alternata, Fusarium oxysporum, Plectosphaerella cucumerina, Paraphoma ledniceana, Fusarium tricinctum, and Fusarium solani; Preferably, the plants are selected from tomato, pepper, wheat, rice, barley, oats, corn, sorghum, millet, buckwheat, broomcorn millet, sweet potato, potato, cotton, sesame, peanut, sunflower, radish, carrot, eggplant, leek, scallion, onion, leek, spinach, celery, amaranth, lettuce, crown daisy, daylily, grape, strawberry, sugarcane, tobacco, Brassica vegetables, cucurbit plants, leguminous plants, tea, cassava, and Chinese herbal medicine plants; Preferably, the Chinese herbal medicine plants are selected from Codonopsis pilosula, Eucommia ulmoides, Scutellaria baicalensis, Cannabis sativa, Isatis indigotica, Astragalus membranaceus, Lonicera japonica, Forsythia suspensa, Phellodendron amurense, Coptis chinensis, Polygonum cuspidatum, Gardenia jasminoides, Paris polyphylla, Bupleurum chinense, Isatis indigotica, Taraxacum mongolicum, Lycium chinense, Anemarrhena asphodeloides, Rehmannia glutinosa, Scrophularia ningpoensis, Sterculia lychnophora, Sargentodoxa cuneata, Paeonia lactiflora, Pulsatilla chinensis, and Paeonia suffruticosa. Preferably, the Bacillus sp. or the microbial agent is used in controlling plant gray mold diseases, plant leaf spot diseases, or plant leaf blight diseases caused by fungi; Preferably, the Bacillus sp. or the microbial agent is used in controlling plant gray mold diseases or plant leaf blight diseases caused by Botrytis cinerea, and the Bacillus sp. or the microbial agent is used in controlling plant leaf spot diseases caused by Alternaria alternata.

5. Use of the Bacillus as claimed in claim 1 or the microbial agent as claimed in claim 2 in promoting plant growth, characterized in that, The plants are selected from tomato, pepper, wheat, rice, barley, oats, corn, sorghum, millet, buckwheat, broomcorn millet, sweet potato, potato, cotton, sesame, peanut, sunflower, radish, carrot, eggplant, leek, scallion, onion, leek, spinach, celery, amaranth, lettuce, crown daisy, daylily, grape, strawberry, sugarcane, tobacco, Brassica vegetables, cucurbit plants, leguminous plants, tea, cassava, and Chinese herbal medicine plants; Preferably, the Chinese herbal medicine plants are selected from Codonopsis pilosula, Eucommia ulmoides, Scutellaria baicalensis, Cannabis sativa, Isatis indigotica, Astragalus membranaceus, Lonicera japonica, Forsythia suspensa, Phellodendron amurense, Coptis chinensis, Polygonum cuspidatum, Gardenia jasminoides, Paris polyphylla, Bupleurum chinense, Isatis indigotica, Taraxacum mongolicum, Lycium chinense, Anemarrhena asphodeloides, Rehmannia glutinosa, Scrophularia ningpoensis, Sterculia lychnophora, Sargentodoxa cuneata, Paeonia lactiflora, Pulsatilla chinensis, and Paeonia suffruticosa.

6. The application according to claim 5, characterized in that, The use includes the following application methods: (1) The Bacillus sp. secretes IAA; (2) The Bacillus sp. dissolves inorganic phosphorus.

7. The application according to claim 6, characterized in that, The application includes at least one of the following application methods: (1) Used as a root drench; (2) Used as a seed soaking agent; (3) Used as a foliar spray.

8. The application according to claim 7, wherein The promotion of plant growth includes at least one of the following applications: (1) Increasing the fresh weight of plants; (2) Increasing the dry weight of plants; (3) Increasing the plant height. Preferably, the use concentration of the Bacillus is 1×10 5 -1×10 8 CFU / mL.

9. The application according to claim 8, characterized in that, At least one of a surfactant, a binder, a stabilizer, a pH regulator, a protective agent, an excipient, a disintegrant, a lubricant, a fragrance, a preservative, a suspending agent, a dispersing agent, and a diluent is further added to the root drench, the seed soaking agent, or the foliar spray.

10. A method for promoting plant growth, characterized in that, It includes the following steps: applying the Bacillus sp. described in claim 1 or the bacterial agent described in claim 2 to plants; The plants are selected from tomato, pepper, wheat, rice, barley, oats, corn, sorghum, millet, buckwheat, proso millet, sweet potato, potato, cotton, sesame, peanut, sunflower, radish, carrot, eggplant, leek, scallion, onion, leek, spinach, celery, amaranth, lettuce, crown daisy, daylily, grape, strawberry, sugarcane, tobacco, Brassica vegetables, Cucurbitaceae plants, Leguminosae plants, tea, cassava, and Chinese herbal medicine plants; Preferably, the Chinese herbal medicine plants are selected from Codonopsis pilosula, Eucommia ulmoides, Scutellaria baicalensis, Cannabis sativa, Isatis indigotica, Astragalus membranaceus, Lonicera japonica, Forsythia suspensa, Phellodendron amurense, Coptis chinensis, Polygonum cuspidatum, Gardenia jasminoides, Paris polyphylla, Bupleurum chinense, Isatis indigotica, Taraxacum mongolicum, Lycium chinense, Anemarrhena asphodeloides, Rehmannia glutinosa, Scrophularia ningpoensis, Sterculia lychnophora, Sargentodoxa cuneata, Paeonia veitchii, Pulsatilla chinensis, and Paeonia suffruticosa; Preferably, the plants are drenched with roots, soaked with seeds, or sprayed on the leaves, stems, or fruits of the plants using the Bacillus sp. Preferably, the use concentration of the Bacillus is 1×10 5 -1×10 8 CFU / mL.

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