Bacillus velezensis DB45 as well as preparation method and application thereof

Abstract

The invention belongs to the technical field of plant disease prevention and treatment, and relates to a bacillus velezensis DB45 as well as a preparation method and application of the bacillus velezensis DB45. The bacillus velezensis DB45 is preserved in the China General Microbiological Culture Collection Center, and the preservation number of the bacillus velezensis DB45 is CGMCC (China General Microbiological Culture Collection Center) No. 28997. The bacillus velezensis DB45 disclosed by the invention can realize efficient prevention and treatment of grape gray mold and has a growth promoting effect on grapes.

Description

Technical Field

[0001] The invention belongs to the technical field of plant disease prevention and control, and specifically relates to a strain of Bacillus velezensis DB45 and a preparation method and application thereof. Background Art

[0002] Grape (Vitis vinifera) is a widely planted fruit tree in the world. At present, large-scale grape cultivation is carried out in Hubei, Hunan, Jiangxi, Guangxi Zhuang Autonomous Region, Liaoning, Beijing, Ningxia Hui Autonomous Region, Yunnan, Jiangsu, Xinjiang Uygur Autonomous Region and other places in China. However, with the development of my country's grape industry, grape diseases have become the main restrictive factor. Common fungal diseases in my country include grape gray mold, downy mildew, anthracnose and the like.

[0003] Grape gray mold, also known as grape gray rot, is a disease caused by Botrytis cinerea. The pathogen belongs to the family Sclerotiniae, genus Botrytis, and is a typical saprophytic fungus. Botrytis cinerea has the characteristics of a wide host range, a long latent period, and strong environmental adaptability. It can cause harm to the entire grape plant and fruit, and has a great impact on the yield and quality of grape fruit. After the occurrence of grape gray mold, the yield will be reduced and the quality of grapes will be reduced, and even no grains will be harvested. In the early stage of grape flowering, the pathogen will infect the grape inflorescence or young panicle. The lesions are light brown in the early stage, and the color becomes darker in the later stage, accompanied by rot and cracking. When the climate conditions are humid, a mouse-gray mold layer is often produced on the diseased part. When the inflorescence is infected, it will wilt, unable to pollinate and cause abortion. In severe cases, the entire panicle falls off. The pathogen can also infect grape fruits through the fruit stems and micro-wounds. The spots on the fruit surface are light brown and sunken in the early stage. In the later stage, the spots will expand and spread to the entire fruit. In severe cases, the entire bunch or part of the grape bunch will rot, and a mouse-gray mold layer will appear on the surface of the diseased fruit. In the later stage of infection, hard black sclerotia will form on the infected part of the grapes. The mold layer will expand and spread to the entire bunch, and the grapes will fall off.

[0004] At present, my country's prevention and control of grape diseases is still mainly based on chemical control using protective fungicides. Some areas have carried out biological control, but the abuse of chemical control agents has led to the development of drug resistance in pathogens, and chemical agents are losing their original control effects. Therefore, the research and development of biological control measures for grape diseases has received attention and has become an important support for the green and high-quality development of the grape industry. Summary of the invention

[0005] The object of the present invention is to provide a strain of Bacillus Velez DB45 and a preparation method and application thereof. The Bacillus Velez DB45 of the present invention can achieve efficient prevention and treatment of grape gray mold and has a growth-promoting effect on grapes.

[0006] The invention provides a strain of Bacillus velez DB45. The Bacillus velez DB45 is deposited in the General Microbiological Center of China National Committee for Microbiological Culture Collection, and the deposit number is CGMCC No.28997.

[0007] The present invention also provides a method for preparing the Bacillus Velezii DB45 bacterial agent described in the above technical solution, comprising the following steps:

[0008] The Velez Bacillus DB45 is cultured to obtain a bacterial agent containing the Velez Bacillus DB45.

[0009] The present invention also provides a product containing the Bacillus Velez DB45 described in the above technical solution, wherein the product includes fermentation liquid, volatiles, culture liquid, metabolic liquid and / or bacterial suspension of Bacillus Velez DB45.

[0010] The present invention also provides the use of the Bacillus Velez DB45 described in the above technical solution or the Bacillus Velez DB45 prepared by the preparation method described in the above technical solution or the product described in the above technical solution in preventing and controlling plant gray mold.

[0011] Preferably, the plant comprises grapes.

[0012] The present invention also provides the use of the Bacillus Velez DB45 described in the above technical solution or the Bacillus Velez DB45 prepared by the preparation method described in the above technical solution or the product described in the above technical solution in inhibiting grape gray mold.

[0013] Preferably, the grape gray mold fungus includes Botrytis cinerea.

[0014] Preferably, the protection against Botrytis cinerea inhibits the growth of mycelium and / or the germination of conidia of Botrytis cinerea.

[0015] The present invention also provides the use of the Bacillus Velez DB45 described in the above technical solution or the Bacillus Velez DB45 prepared by the preparation method described in the above technical solution or the product described in the above technical solution in promoting the growth of grapes.

[0016] Preferably, the promoting grape growth comprises increasing one or more of the following grape indicators: grape leaf length, leaf width, chlorophyll content, fruit size, 100-grain weight and fruit soluble solid content.

[0017] The present invention provides a strain of Bacillus velezensis DB45. The Bacillus velezensis DB45 of the present invention can achieve efficient prevention and treatment of grape gray mold, and has a growth-promoting effect on grapes. Test results show that compared with other bacteria screened, the Bacillus velezensis DB45 of the present invention has a better prevention and treatment effect on grape gray mold; specifically, it can inhibit the growth of grape gray mold hyphae and / or the germination of conidia; and increase grape leaf length, leaf width, chlorophyll content, fruit size, 100-grain weight and fruit soluble solid content. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0019] Figure 1 The graphs show the symptoms (a), disease index (b) and control effect (c) of gray mold on grape fruits after being treated with different bacteria provided by the present invention;

[0020] Figure 2 A phylogenetic tree result diagram of the biocontrol bacteria provided by the present invention jointly constructed based on 16S rDNA and gyrA genes;

[0021] Figure 3 The figure is a result of the effect of the biocontrol bacteria culture solution, metabolic solution and bacterial suspension provided by the present invention on the colony morphology of Botrytis cinerea;

[0022] Figure 4 The diagram shows the inhibitory effect of the biocontrol bacteria culture solution (left), bacterial suspension (middle) and metabolic solution (right) provided by the present invention on the hyphae of Botrytis cinerea;

[0023] Figure 5 This is a result diagram of the effect of the volatile substances of the biocontrol bacteria provided by the present invention on the mycelial growth of Botrytis cinerea;

[0024] Figure 6 A result diagram showing the effect of the biocontrol bacteria provided by the present invention on the conidia germination of Botrytis cinerea;

[0025] Figure 7 This is a graph showing the results of the bacterial amylase production capacity test provided by the present invention;

[0026] Figure 8 A graph showing the results of the detection of the cellulase production capacity of bacteria provided by the present invention;

[0027] Fig. 9This is a graph showing the results of the bacterial phosphate solubilization ability test provided by the present invention.

[0028] Biological deposit information

[0029] Bacillus velezensis DB45 is deposited in the General Microbiology Center of China Microbiological Culture Collection Administration on November 14, 2023. The address is No. 3, Yard No. 1, Beichen West Road, Chaoyang District, Beijing, and the deposit number is CGMCC No. 28997. DETAILED DESCRIPTION

[0030] The present invention provides a strain of Bacillus velezensis DB45, which is deposited in the General Microbiology Center of the China National Microbiological Culture Collection Administration, with a deposit number of CGMCC No. 28997. Through in vitro grape fruit bioassay, a total of 151 strains of bacteria were screened for grape gray mold, and finally a strain of bacteria with high protective effect against grape gray mold was obtained, Bacillus velezensis DB45, with a protective effect of more than 80%. The Bacillus velezensis DB45 described in the present invention is deposited in the General Microbiology Center of the China National Microbiological Culture Collection Administration, and the deposit time is November 14, 2023. The address is No. 3, Yard No. 1, Beichen West Road, Chaoyang District, Beijing, and the deposit number is CGMCC No. 28997. Based on the joint construction of the phylogenetic tree of 16SrDNA and gyrA genes, the bacterium DB45 screened by the present invention was identified as Bacillus velezensis. The morphological characteristics of the Velez Bacillus DB45 of the present invention are as follows: the colonies are nearly round, opaque milky white, and smooth in the early stage of cultivation, and the colonies change from full to collapsed in the middle, forming wrinkles in the later stage. The Velez Bacillus DB45 of the present invention can produce amylase, cellulase and phosphate-soluble related substances.

[0031] The present invention also provides a method for preparing the Bacillus Velezii DB45 bacterial agent described in the above technical solution, comprising the following steps:

[0032] The Velez Bacillus DB45 is cultured to obtain a bacterial agent containing Velez Bacillus DB45. The present invention has no particular limitation on the culture method, and any method and condition that can achieve the culture of Velez Bacillus DB45 is within the protection scope of the present application.

[0033] The present invention also provides a product containing the Bacillus Velez DB45 described in the above technical solution, and the product includes the fermentation broth, volatiles, culture fluid, metabolic fluid and / or bacterial suspension of Bacillus Velez DB45. The present invention does not specifically limit the preparation method of the fermentation broth, volatiles, culture fluid, metabolic fluid and bacterial suspension, and can be prepared by conventional preparation methods well known to those skilled in the art. For example, the present invention preferably inoculates DB45 into a liquid culture medium for culture to obtain a culture fluid. After obtaining the culture fluid, the present invention preferably centrifuges the culture fluid, sterilizes the supernatant to obtain a metabolic fluid; and resuspends the precipitate to obtain a bacterial suspension.

[0034] The present invention also provides the use of the Bacillus Velez DB45 described in the above technical solution or the Bacillus Velez DB45 prepared by the preparation method described in the above technical solution or the product described in the above technical solution in preventing and controlling plant gray mold. In the present invention, the plant preferably includes grapes. The results of the embodiment show that the Bacillus Velez DB45 of the present invention has a high prevention effect on grape gray mold, with a prevention effect of more than 80%.

[0035] The present invention also provides the use of the Velez Bacillus DB45 described in the above technical solution or the Velez Bacillus DB45 prepared by the preparation method described in the above technical solution or the product described in the above technical solution in inhibiting the Botrytis cinerea. In the present invention, the Botrytis cinerea preferably includes Botrytis cinerea. In the present invention, the inhibition of Botrytis cinerea protects the growth of the hyphae and / or the germination of conidia of the Botrytis cinerea. The test results show that the Velez Bacillus DB45 of the present invention can inhibit the growth of the hyphae of the Botrytis cinerea and significantly inhibit the germination of conidia.

[0036] The present invention also provides the use of the Bacillus Velez DB45 described in the above technical solution or the Bacillus Velez DB45 prepared by the preparation method described in the above technical solution or the product described in the above technical solution in promoting the growth of grapes. In the present invention, the promotion of grape growth preferably includes increasing one or more of the following indicators of grapes: grape leaf length, leaf width, chlorophyll content, fruit size, 100-grain weight and fruit soluble solid content.

[0037] To further illustrate the present invention, a strain of Bacillus velezensis DB45 provided by the present invention, as well as its preparation method and application are described in detail below in conjunction with the accompanying drawings and examples, but they should not be construed as limiting the scope of protection of the present invention.

[0038] Example 1

[0039] 1. Determination of the protective efficacy of the selected bacteria on isolated grape berries

[0040] Through in vitro grape fruit bioassay, a total of 151 strains of bacteria were screened for grape gray mold, and 11 strains of bacteria with inhibitory effects on grape gray mold were obtained in the initial screening. After 3 complete rescreening verifications, according to the difference in the prevention and control effects of indoor in vitro bioassays, the 11 strains of bacteria screened by the present invention were divided into bacteria with strong prevention effects, bacteria with medium prevention effects, and bacteria with weak prevention effects. Bacteria with strong prevention effects include DB45 (prevention effects above 70%), bacteria with medium prevention effects include XPL0 (prevention effects between 60% and 70%), and bacteria with weak prevention effects include DB37 (prevention effects below 60%). The relative prevention effect calculation formula is as follows:

[0041] Relative protective effect = (disease index of treatment group - disease index of control group) / disease index of control group × 100%.

[0042] These three strains of biocontrol bacteria with control effects on grape gray mold were selected for subsequent field trials.

[0043] The in vitro efficacy test of bacteria DB37, DB45, and XPL0, which were used for further field verification of the control effect of grape gray mold, showed that the three strains of bacteria had different degrees of control effect on grape gray mold. When the grape fruits treated with bacterial culture solution were inoculated with gray mold pathogens, the symptoms began to appear the next day. The grape fruits in the control group inoculated with pathogens in clean water immediately showed symptoms the next day. Five days after inoculation, the grape fruits in the control group had serious symptoms of the disease, with light brown spots around the pathogen inoculation and slight rot symptoms. The grape fruits treated with bacterial DB45 culture solution did not show obvious brown spots, and the overall disease index was low. The relative control effect was more than 80%, specifically 86%, showing a good control effect. In the bacterial XPL0 and DB37 culture solution treatment groups, some fruits showed slight brown water-soaked spots, but the disease was less severe than that in the control group, and the relative control effects reached 56.9% and 61.7%, respectively, which also showed a certain control effect. Symptoms (a), disease index (b) and control effect (c) of gray mold on grape berries after treatment with different bacteria Figure 1 shown.

[0044] 2. Verification of the control effect of biocontrol bacteria on detached fruits

[0045] To further verify the control effect of the screened bacteria on grape gray mold, the control effect of bacteria DB45, XPL0 and DB37 on grape gray mold was verified by in vitro bioassay in which the pathogen was inoculated in a wound and then the bacterial culture solution was sprayed (LB liquid medium at 37°C and shaking at 200rpm for 48h). The results showed that the three strains all had control effects on grape gray mold and had a certain inhibitory effect on the expansion of lesions. Among them, DB45 had the most significant effect, with a therapeutic effect of 33.8%.

[0046] 3. Field trials of biocontrol bacteria

[0047] Preparation method of bacterial fermentation broth: inoculate the strain into a 5 mL nutrient broth (NB) medium test tube, shake culture at 37°C, 200 rpm overnight, then transfer the bacterial solution to a 100 mL NB conical flask at a 1:100 inoculation rate, shake culture at 37°C, 200 rpm for 48 h to obtain fermentation broth.

[0048] The fermentation liquid of three strains of bacteria was used to conduct field control efficacy tests in Jinan and Penglai, Shandong Province. The tested bacteria all had control effects on Botrytis cinerea. In Jinan and Penglai, Shandong Province, the fermentation liquid of bacteria DB45 had better field control effects on Botrytis cinerea than other bacterial fermentation liquids. In Jinan, Shandong Province, the field disease control effect of bacteria DB45 was more than 50%, and in Penglai, Shandong Province, the field disease control effect of bacteria DB45 was more than 40%. The control effects of bacteria XPL0 and DB37 on Botrytis cinerea were relatively poor. In the Jinan test site, DB37 had an increase in control efficacy in the second survey, while the control efficacy of XPL0 and DB45 in the second survey decreased compared with the first survey. Similar changes also occurred in the Penglai test site, but overall, they all showed control effects and still had certain application prospects. The results are shown in Tables 1 and 2.

[0049] Table 1 Field control effect of biocontrol bacteria on gray mold of “Gem Seedless” grape in Jinan, Shandong

[0050]

[0051] Table 2 Field control effect of biocontrol bacteria on gray mold of “Guirenxiang” grape in Penglai, Shandong

[0052]

[0053] The field control effect test was carried out in Sandu County, Guizhou Province using fermented liquid of three strains of bacteria. It was found that the selected bacteria had a certain control effect on grape anthracnose. Bacteria DB45 and XPL0 had a good control effect on the anthracnose of "Shuijing" grapes in Sandu County, Guizhou Province. Among them, bacteria DB45 had the best control effect, reaching 83.7%, and bacteria DB37 had a control effect of 61.2%. Bacteria DB45 and DB37 had a good control effect on the anthracnose of "Guirenxiang" grapes in Penglai, Shandong Province, both of which were 61.8%, while bacteria XPL0 had a relatively poor control effect of 8.88%. The results showed that bacteria DB45 and DB37 had a significant control effect on field grape gray mold. The results are shown in Tables 3 and 4.

[0054] Table 3 Field control effect of biocontrol bacteria on anthracnose of Guizhou Sandu "Crystal" grape

[0055] deal with Incidence (%) Disease index Control effect (%) CK 46.67±2.72a 18.15±2.69a XPL0 23.33±7.20b 5.56±2.40b 69.39±13.23a DB45 20.00±4.71b 2.96±1.09b 83.68±6.01b DB37 16.67±7.20b 7.04±4.87b 61.23±26.81a

[0056] Table 4 Field control effect of biocontrol bacteria on anthracnose of “Guirenxiang” grape in Penglai, Shandong

[0057] deal with Incidence (%) Disease index Control effect (%) CK 44.44±1.81a 8.40±1.41a XPL0 25.56±6.44b 7.65±2.53a 8.88±30.07b DB37 13.56±2.06b 3.21±1.28a 61.79±7.56a DB45 14.78±2.18b 3.18±0.53a 60.27±6.36a

[0058] In the Sandu test site in Guizhou, the fermented bacterial liquid was used to dip the ears, which significantly improved the fruit size and 100-grain weight. The growth-promoting effect of the bacteria DB45 was the most significant, with the grain length increasing by 1.9 mm, the 100-grain weight increasing by 16.3 g and 14.7 g, and the soluble solid content increasing by 1% and 0.9%. The other bacterial treatments also had a certain improvement on the fruit size, yield and soluble solids, but the growth-promoting effect was relatively unobvious. The results are shown in Table 5.

[0059] Table 5 Effects of biocontrol bacteria on the quality of Guizhou Sandu "Crystal" grape fruit

[0060]

[0061] After applying bacterial fermentation liquid in the experimental field in Jinan, Shandong, leaf length, leaf width and chlorophyll content were promoted to a certain extent. Among them, bacteria DB45 and DB37 had the best growth promotion effect, and the chlorophyll content increased by 2.9 SPAD and 3.3 SPAD respectively. The results are shown in Table 6.

[0062] Table 6 Effects of biocontrol bacteria on leaves of “Bao Shi Seedless” grapes in Jinan, Shandong

[0063]

[0064] After applying bacterial fermentation liquid in the test field in Penglai, Shandong, the fruit size and 100-grain weight increased significantly. Among them, the bacteria DB45 can also significantly increase the soluble solid content of the fruit, and other treatments have no significant effect on the soluble solid content. The tested bacterial treatments have no significant effect on leaf size. Bacteria DB37 and DB45 can significantly increase the chlorophyll content of the leaves, and the chlorophyll content of the XPL0 bacteria treatment has no significant increase. The results are shown in Table 7.

[0065] Table 7 Effects of biocontrol bacteria on fruits and leaves of “Guirenxiang” grape in Penglai, Shandong

[0066]

[0067] 4. Results of molecular biological identification of biocontrol bacteria

[0068] The phylogenetic tree of the three bacterial strains obtained by screening was constructed based on 16S rDNA and gyrA genes. The strains of biocontrol bacteria obtained by screening were identified as Bacillus, among which bacteria XPL0 and DB45 were Bacillus velezensis, and DB37 was Bacillus atrophaeus. The phylogenetic tree of biocontrol bacteria based on 16S rDNA and gyrA genes was shown in the figure. Figure 2 shown.

[0069] 5. Inhibition of the growth of Botrytis cinerea by biocontrol bacterial culture solution, metabolic solution and bacterial suspension

[0070] The culture solution and bacterial suspension of bacteria XPL0, DB37 and DB45 all showed inhibitory effects on the mycelial growth of grape gray mold. The culture solution, bacterial suspension and metabolic solution of DB45 (use a sterilized toothpick to pick the single colonies of the biocontrol bacteria obtained by screening and put them into a test tube containing 5mL LB liquid culture medium, place it in a 37℃ constant temperature water bath shaker, and shake it at 200rpm for 12h. When the culture solution becomes turbid, dilute it with LB liquid culture medium to OD 600 is 0.8, take 4mL of the bacterial solution and inoculate it into a 500mL Erlenmeyer flask containing 200mL of liquid LB culture medium, shake and culture under the same conditions for 48h to obtain the culture solution. After the culture is completed, divide it into 5mL centrifuge tubes and centrifuge to preliminarily separate the metabolic supernatant and bacterial precipitate. The supernatant metabolic liquid is sterilized by a bacterial filter to obtain a sterile metabolic liquid. The centrifuged bacteria are washed with LB liquid culture medium and centrifuged 3 times, the precipitated bacteria are collected, and the bacterial suspension is obtained by shaking and suspending with 5mL LB liquid culture medium) can inhibit the growth of grape gray mold hyphae. The bacterial suspensions of DB37 and XPL0 have an inhibitory effect, while the metabolic liquid does not show an inhibitory effect. Among the three bacteria, the culture solution of bacteria DB37 has the best inhibitory effect on hyphae growth, the bacterial suspension of DB45 has the best inhibitory effect on the hyphae growth of gray mold fungi, and the metabolic liquid of bacteria DB45 has the best inhibitory effect on hyphae growth. The results of the effects of biocontrol bacteria culture solution, metabolic liquid and bacterial suspension on the colony morphology of grape gray mold fungi are shown in the figure. Figure 3 The inhibitory effects of biocontrol bacteria culture solution (left), bacterial suspension (middle) and metabolic solution (right) on the mycelium of Botrytis cinerea Figure 4 shown.

[0071] 6. Effects of volatile substances of biocontrol bacteria on mycelial growth

[0072] The inhibitory effects of volatiles from bacteria XPL0, DB37 and DB45 were studied using a matching culture medium. The results showed that the volatiles from the three selected bacteria all had an inhibitory effect on the mycelial growth of Botrytis cinerea. The colony diameter under the treatment of bacteria DB45 was significantly reduced, and the inhibitory effect was more obvious. Among them, the colony diameter under the treatment of bacteria DB45 was the smallest, and the inhibitory effect was the best. The colony diameters under the treatment of bacteria XPL0 and DB37 were similar, and the inhibitory effect was relatively weak.

[0073] The results of the effects of volatile substances of biocontrol bacteria on the mycelial growth of Botrytis cinerea Figure 5 Note: a is the colony morphology under different treatments; b is the colony diameter result under different treatments.

[0074] 7. Effect of biocontrol bacteria culture solution on conidia germination of grape gray mold

[0075] Depend on Figure 6 It can be seen that the culture fluid of bacteria DB45 and DB37 can significantly inhibit the germination of conidia of grape gray mold. Among them, under the treatment of DB45 bacterial culture fluid, the conidia of gray mold did not germinate. Under the treatment of bacterial XPL0 and DB37 culture fluid, most of the conidia of gray mold germinated, but the length of the conidia was shorter than that of the control group, which also showed a certain inhibitory effect. The results of the effect of biocontrol bacteria on the germination of conidia of gray mold are shown in the figure. Figure 6 Note: a is the conidia morphology under different treatments; b is the conidia germination rate result under different treatments.

[0076] 8. Detection of active substances in biocontrol bacteria

[0077] The activities of the enzymes were determined using cellulase, amylase and phosphate-dissolving identification medium. The results showed that bacteria XPL0 and DB45 could produce amylase, cellulase and phosphate-dissolving related substances, while bacteria DB37 could not produce cellulase.

[0078] The results of the bacterial amylase production test are as follows Figure 7 The results of the bacterial cellulase production test are shown in Figure 8 The results of the bacterial phosphate solubilization test are shown in Fig. 9 shown.

[0079] Although the above embodiment describes the present invention in detail, it is only a part of the embodiments of the present invention, not all of the embodiments. People can also obtain other embodiments based on this embodiment without creativity, and these embodiments all fall within the protection scope of the present invention.

Claims

1. A strain of Bacillus velezensis DB45, characterized in that: The Bacillus velezensis DB45 is deposited in the General Microbiology Center of China National Microbiological Culture Collection Administration, with the deposit number being CGMCC No.28997.

2. The method for preparing the Bacillus Velezii DB45 agent according to claim 1 comprises the following steps: The Velez Bacillus DB45 is cultured to obtain a bacterial agent containing the Velez Bacillus DB45.

3. A product containing the Bacillus Velezii DB45 according to claim 1, characterized in that: The product comprises fermentation liquid, volatile matter, culture liquid, metabolic liquid and / or bacterial suspension of Bacillus velez DB45.

4. Use of the Bacillus Velez DB45 according to claim 1 or the Bacillus Velez DB45 prepared by the preparation method according to claim 2 or the product according to claim 3 in preventing and controlling plant gray mold.

5. The use according to claim 4, characterized in that: The plants include grapes.

6. Use of the Bacillus Velez DB45 according to claim 1 or the Bacillus Velez DB45 prepared by the preparation method according to claim 2 or the product according to claim 3 in inhibiting Botrytis cinerea.

7. The use according to claim 6, characterized in that: The grape gray mold fungi include Botrytis cinerea.

8. The use according to claim 6, characterized in that: The protection against Botrytis cinerea inhibits the growth of mycelium and / or the germination of conidia of Botrytis cinerea.

9. Use of the Bacillus Velez DB45 according to claim 1 or the Bacillus Velez DB45 prepared by the preparation method according to claim 2 or the product according to claim 3 in promoting grape growth.

10. The use according to claim 9, characterized in that: The promoting of grape growth comprises increasing one or more of the following indexes of grapes: grape leaf length, leaf width, chlorophyll content, fruit size, 100-grain weight and fruit soluble solid content.

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