Marine sediment bacillus Sneb2538 as well as fermentation liquor and application thereof

Abstract

The invention relates to the technical field of plant disease prevention and control, and particularly discloses a marine sediment bacillus Sneb2538 and fermentation liquor and application thereof, the marine sediment bacillus Sneb2538 is preserved in China General Microbiological Culture Collection Center on August 12, 2024, the preservation number is CGMCC No.31569, and the marine sediment bacillus Sneb2538 is classified and named as marine sediment bacillus. The marine sediment bacillus Sneb2538 provided by the invention can be used for effectively preventing and treating fusarium wilt of cucumbers and promoting the growth of cucumber plants.

Description

Technical Field

[0001] The invention relates to the technical field of plant disease prevention and control, and in particular to a marine sediment Bacillus Sneb2538 and a fermentation liquid and application thereof. Background Art

[0002] With the continuous development of cucumber production in scale, base and specialization and the changes in the ecological environment, the occurrence and harm of cucumber diseases are becoming more and more serious. Among them, cucumber wilt caused by Fusarium oxysporumf.sp.cucumerinum Owen is a soil-borne fungal disease that causes serious harm in cucumber production. The pathogen can easily survive under natural conditions and is mainly spread through soil, seeds and fertilizers. Cucumber wilt has the characteristics of short onset time, wide occurrence area, high degree of harm and high difficulty in prevention and control. The general incidence of cucumber wilt is 20% to 50%, and can reach more than 80% when the damage is serious.

[0003] Cucumber wilt is the main factor that causes the death of cucumbers in continuous cultivation in facilities, and it can occur throughout the entire growth cycle of cucumbers. Cucumber wilt bacteria mainly infect the vascular bundles of the cucumber stems and invade the plant through root hairs or root wounds. The expansion and spread of the disease will accelerate the death of the entire plant. The base of the affected stems of cucumbers in the seedling stage will turn yellow-brown, and the cotyledons of the seedlings will wither. When the damage is serious, the base of the stems will shrink and the seedlings will die. The damage caused by cucumber wilt is particularly serious during the flowering to fruiting period. After being affected in the adult stage, the leaves of the diseased plants gradually die from top to bottom. The base of the main vine of the diseased plant is slightly shrunk, and longitudinal cracks can often be observed. Cut the diseased stem longitudinally, and the vascular bundles can be observed to turn brown. Under high humidity conditions, white or pink mildew will appear on the surface of the diseased part, which will eventually lead to root rot, making the plant easy to be pulled up.

[0004] For a long time, the prevention and control of cucumber wilt disease mainly relied on chemical pesticides. Although the application of chemical pesticides has achieved certain results, its harm to human and animal health and the ecological environment is becoming increasingly serious and has received widespread attention. Biological control is highly praised for its good environmental compatibility, long duration and pollution-free characteristics. Studies have shown that the imbalance of soil microbial population structure is the main cause of cucumber wilt disease. Therefore, under the continuous cropping production mode, using biocontrol microorganisms to regulate the rhizosphere soil microbial population structure and create a healthy soil microbial environment is a safe and effective strategy to solve cucumber wilt disease. It can be seen that it is of great significance to isolate and screen microorganisms from nature for the prevention and control of cucumber wilt disease. Summary of the invention

[0005] In order to provide a microorganism for preventing and treating cucumber wilt, the present invention provides a marine sediment Bacillus Sneb2538 and its fermentation liquid and application. The marine sediment Bacillus Sneb2538 provided by the present invention can effectively prevent and treat cucumber wilt and promote the growth of cucumber plants.

[0006] The present invention provides a strain of marine sediment Bacillus (Cytobacillus oceanisediminis) Sneb2538. The marine sediment Bacillus Sneb2538 was deposited in the General Microbiological Center of China National Committee for Microbiological Culture Collection on August 12, 2024, with a deposit number of CGMCC No.31569, and was classified and named as marine sediment Bacillus Cytobacillus oceanisediminis.

[0007] The present invention isolates a marine sediment Bacillus Sneb2538 from nature. Experimental verification shows that the strain can effectively prevent and control cucumber wilt and promote the growth of cucumber plants, laying a practical foundation for cucumber cultivation.

[0008] The present invention also provides a fermentation liquid obtained by fermenting the marine sediment Bacillus Sneb2538, wherein the fermentation liquid is obtained by inoculating the marine sediment Bacillus Sneb2538 into a liquid culture medium and culturing the culture medium until the strain concentration is 1×10 7 CFU / mL~1×10 8 CFU / mL obtained.

[0009] The present invention also provides a method for preparing the fermentation liquid, wherein the steps of preparing the fermentation liquid are: activating the marine sediment Bacillus Sneb2538 and inoculating it into a liquid fermentation medium at a temperature of 26°C to 28°C and 150r·min -1 ~200r·min -1 Shake the culture for 1.5 to 2 days to obtain the fermentation liquid.

[0010] Furthermore, the liquid fermentation medium is LB broth medium.

[0011] Furthermore, the fermentation liquid is prepared by activating the marine sediment Bacillus Sneb2538 and inoculating it into a liquid fermentation medium at a temperature of 28°C and 200 r·min -1 After shaking cultivation for 2 days, the fermentation liquid was obtained.

[0012] The present invention also provides an application of the marine sediment Bacillus Sneb2538 or the fermentation liquid in cucumber cultivation. The marine sediment Bacillus Sneb2538 or the fermentation liquid is used for preventing and controlling cucumber wilt and promoting the growth of cucumber plants.

[0013] Furthermore, the marine sediment Bacillus Sneb2538 is used to inhibit the cucumber wilt pathogen Fusarium oxysporum f.sp.cucumerinum Owen.

[0014] Furthermore, the marine sediment Bacillus Sneb2538 is used to inhibit the germination of Fusarium oxysporum spores.

[0015] Furthermore, the fermentation liquid of the marine sediment Bacillus Sneb2538 is used to treat cucumber seedlings through root irrigation to prevent and control cucumber wilt.

[0016] Furthermore, the promoting the growth of cucumber plants includes: increasing the plant height, plant fresh weight and root fresh weight of the cucumber plants.

[0017] Compared with the prior art, the present invention has the following beneficial effects:

[0018] The marine sediment Bacillus Sneb2538 isolated and obtained by the present invention can effectively prevent and control cucumber wilt disease and promote the growth of cucumber plants. The marine sediment Bacillus Sneb2538 can act on cucumber plants in various forms, thereby preventing and controlling cucumber wilt disease; for example, the marine sediment Bacillus Sneb2538 is made into pure bacterial powder, freeze-dried powder, bacterial agent and other products and acts on cucumber plants, thereby achieving the purpose of preventing and controlling cucumber wilt disease and promoting the growth of cucumber plants.

[0019] In the indoor pot plant experiment and field experiment of the present invention, the fermentation liquid prepared by marine sediment Bacillus Sneb2538 can be used for root irrigation treatment of cucumber seedlings to effectively prevent and control wilt disease and promote plant growth.

[0020] Information on the deposit of biological materials

[0021] Sneb2538, referred to as marine sediment Bacillus Sneb2538 in this application, was deposited in the General Microbiology Center of China Microorganism Culture Collection Administration on August 12, 2024, with the deposit number CGMCC No.31569. The address of the depository is No. 3, Yard 1, Beichen West Road, Chaoyang District, Beijing, Postal Code: 100101, and the classification name is marine sediment Bacillus Cytobacillus oceanisediminis. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] 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 or the description of the prior art 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 work.

[0023] Figure 1 This is a diagram showing the results of a plate confrontation experiment between Bacillus Sneb2538 and Fusarium oxysporum in marine sediments; in the figure, A is Fusarium oxysporum; B is a confrontation diagram between Sneb2538 and Fusarium oxysporum. DETAILED DESCRIPTION

[0024] The specific embodiments of the present invention are described in detail below, but it should be understood that the protection scope of the present invention is not limited by the specific embodiments. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without creative work belong to the scope of protection of the present invention. The experimental methods described in the embodiments of the present invention are conventional methods unless otherwise specified, and the materials, reagents, etc. used in the following embodiments can be obtained from commercial channels unless otherwise specified.

[0025] Example 1: Isolation of a marine sediment Bacillus Sneb2538 and preparation of its fermentation broth.

[0026] 1. Isolation of Bacillus Sneb2538 from marine sediments

[0027] A marine sediment Bacillus Sneb2538 was isolated and purified from soil collected from a cucumber field in Yuhong District, Shenyang City, Liaoning Province (123.162° longitude, 41.949° latitude).

[0028] 2. Preparation of fermentation broth of Bacillus Sneb2538 from marine sediments

[0029] (1) The purified marine sediment Bacillus Sneb2538 was activated on LB solid medium for 12 h.

[0030] The solid culture medium (LB culture medium) consists of 10.0 g of peptone, 5.0 g of yeast powder, 5.0 g of sodium chloride, 1.0 g of glucose, and 15-20 g of agar; dissolved in 1.0 L of distilled water, pH 7.0±0.2, 121° C., 30 min, and sterilized by wet heat.

[0031] (2) Pick a single colony with good growth on the LB solid medium and inoculate it into 150 mL of liquid fermentation medium for shaking fermentation at a temperature of 28°C and a shaking speed of 200 r / min. -1 The fermentation time was 2 days, and the fermentation liquid was obtained.

[0032] The liquid fermentation medium (LB broth) consists of 10.0 g of peptone, 5.0 g of yeast powder, 5.0 g of sodium chloride, and 1.0 g of glucose; pH 7.0±0.2, dissolved in 1.0 L of distilled water, and sterilized by wet heat at 121° C. for 30 min.

[0033] Example 2: Antagonistic effect of marine sediment Bacillus Sneb2538 fermentation broth on Fusarium oxysporum and inhibitory effect on its spore germination.

[0034] 1. Experimental Methods

[0035] 1. Study on the antagonistic effect of fermentation broth on Fusarium oxysporum

[0036] The strain Fusarium oxysporum f.sp.cucumerinum Owen was donated by Professor Liu Zhiheng from the Fungal Laboratory of the College of Plant Protection, Shenyang Agricultural University. The strain was recorded in the Chinese Journal of Biological Control, and the article title is: Optimization of fermentation conditions of Streptomyces combination ST-2 and its control effect on cucumber wilt.

[0037] The strain of Fusarium oxysporum f.sp.cucumerinum Owen was activated on a PDA plate and inverted for 4 days at 28°C. A bacterial cake was punched at the edge of the colony of Fusarium oxysporum f.sp.cucumerinum Owen with a hole puncher (d=9 mm), placed in the center of a new PDA medium plate, and 2 μL of marine sediment Bacillus Sneb2538 fermentation liquid was dropped symmetrically at a distance of 2.0 cm from the bacterial cake. A plate inoculated with only the pathogenic bacterial cake but not the fermentation liquid was used as a control. The plate was placed at 28°C for 4 days until the control pathogenic bacterial colony filled the culture dish, the radius of the pathogenic bacterial colony was observed and recorded, and the inhibition rate was calculated.

[0038] Potato dextrose agar medium (PDA), composed of 200 g potato (peeled), 20 g glucose, and 15 g agar, dissolved in 1.0 L distilled water, pH adjusted to 7.2-7.5, and sterilized by wet heat at 121°C for 30 min.

[0039] Potato glucose liquid medium (PD), composed of 200g potato (peeled) and 20g glucose, dissolved in 1.0L distilled water, pH adjusted to 7.2-7.5, sterilized by wet heat at 121°C for 30min.

[0040]

[0041] 2. Inhibitory effect of fermentation broth on spore germination of Fusarium oxysporum

[0042] Inoculate the mycelium of Fusarium oxysporum on PDA solid medium, culture at 28℃ for 7 days, and the culture dish is full of pathogens. Under sterile conditions, add 5mL of sterile water to the PDA plate full of pathogenic bacteria, scrape the fungal mycelium with a disposable inoculation loop, and filter with 3 layers of sterile gauze to obtain the spore suspension of Fusarium oxysporum. Mix 40μL of fermentation broth and 40μL of Fusarium oxysporum spore suspension in a ratio of 1:1 and transfer to a sterile glass slide, and place the glass slide at 28℃ and culture for 12h. Add equal amounts of sterile water and LB liquid culture medium to the pathogen spore suspension as control treatments. After incubation, observe the spore germination of Fusarium oxysporum under a microscope, record the number of germinated spores and check the total number of spores, and calculate the spore germination rate and relative inhibition rate.

[0043]

[0044]

[0045] 2. Experimental Results

[0046] From the plate confrontation test, the colony radius of the control Fusarium oxysporum was 3.92 cm, and after being treated with the fermentation filtrate of the Sneb2538 strain, the colony radius of Fusarium oxysporum was 1.42 cm, and the inhibition rate of Fusarium oxysporum was 63.78%, indicating that the strain Sneb2538 can effectively antagonize the growth of Fusarium oxysporum.

[0047] From the spore germination inhibition test, it can be seen that after 12 hours of treatment, the spore germination rates of sterile water and PD liquid culture medium treatment were 100.000% and 100.00%, and the spore germination rate of Sneb2538 strain fermentation filtrate treatment was 43.22%, which was significantly lower than that of the control, and the relative inhibition rate of spore germination was 56.78%, indicating that marine sediment Bacillus Sneb2538 significantly inhibited the spore germination of Fusarium oxysporum.

[0048] Example 3: Effects of the fermentation broth of marine sediment Bacillus Sneb2538 on the germination and growth of cucumber seeds.

[0049] 1. Experimental Methods

[0050] 1. Experimental Materials

[0051] The cucumber variety was Zhongnong No. 6. The seeds were sterilized by soaking in warm water (55°C for 30 min) and set aside.

[0052] The fermentation broth prepared in Example 1.

[0053] Instruments and appliances: steam sterilizer, electric constant temperature air drying oven, electric constant temperature incubator, clean workbench, disposable culture dish, shaking incubator, seedling tray.

[0054] 2. Experimental steps

[0055] The sterilized seeds were soaked in the fermentation liquid of the strain for 3 minutes for coating treatment, and then placed in a sterile culture dish (d = 90 mm) covered with sterile filter paper. Each treatment was repeated 3 times, with 10 seeds in each repeat, and the same amount of sterile water and culture medium were used as controls. The culture dish was placed in a constant temperature and humidity incubator controlled at 25°C for 24 hours and then the number of germinated seeds was counted. The number was counted once a day. After 7 days of cultivation, the germination index and germination rate were calculated, and the bud length and root length were measured to calculate the seed vitality index.

[0056]

[0057]

[0058] Seed vigor index = seedling length × germination index.

[0059] 2. Experimental Results

[0060] Table 1 Effect of fermentation liquid on cucumber seed germination and growth

[0061] deal with Germination rate / % Germination Index Seed Vitality Index Root length / cm <![CDATA[ddH2O]]> 76.67±5.77a 0.96±0.14a 2.38±0.07b 2.52±0.28a LB 73.33±5.77a 0.90±0.06a 2.25±0.33b 2.49±0.45a Sneb2538 83.33±5.77a 1.03±0.22a 3.90±0.65a 3.99±1.37a

[0062] Note: The data in the table are mean ± standard deviation. Different letters in the same column indicate significant differences at the P < 0.05 level tested by Duncan's method.

[0063] As shown in Table 1, after the cucumber seeds were treated with the fermentation liquid of strain Sneb2538, the germination rate of the cucumber seeds was 83.33%, the germination index was 1.0, the seed vigor index was 3.90, and the root length was 3.99 cm. Compared with the control, the seed vigor index of the cucumber seeds increased significantly, and the germination rate, germination index and root length all increased, indicating that the fermentation liquid of marine sediment Bacillus Sneb2538 for soaking and coating cucumber seeds not only had no inhibitory effect on cucumber seed germination and plant growth, but also significantly increased the seed vigor index.

[0064] Example 4: Study on the protective effect of marine sediment Bacillus Sneb2538 fermentation broth against cucumber wilt.

[0065] 1. Experimental Methods

[0066] 1. Experimental Materials

[0067] The fermentation broth prepared in Example 1.

[0068] Prepare spore suspension according to the above method for culturing Fusarium oxysporum and set aside.

[0069] The cucumber variety is Zhongnong No. 6.

[0070] 2. Experimental steps

[0071] Cucumber seeds were sterilized by soaking in warm water (55°C for 30 min). The sterilized seeds were sown in a seedling tray filled with nutrient soil, which was a mixture of sand and seedling substrate in a volume ratio of 1:1. Before sowing, the nutrient soil was sterilized at 160°C for 180 min and cultured in a greenhouse at 25°C, 16h light and 8h dark for about two weeks. After the two-leaf and one-heart stage, the cucumber seedlings were transplanted into 9.5cm×11.5cm pots, with one seedling in each pot, for later use.

[0072] The seedling medium (mainly composed of peat soil) was purchased from Pinstop Horticulture Ltd. of Denmark. The brand is Pinstop medium, the product number is msh-1013, the product is 10-30 mm, and Pinstop peat soil is 80 L.

[0073] The following treatments were designed in the experiment: sterile water root irrigation without pathogen inoculation was used as blank control (ddH2O), sterile water root irrigation and inoculation of Fusarium oxysporum fermentation liquid (ddH2O+F.), LB medium root irrigation and inoculation of Fusarium oxysporum fermentation liquid (LB+F.), and agent (mass fraction 1.8% thiophanate methyl) root irrigation and inoculation of Fusarium oxysporum fermentation liquid (1.8% thiophanate methyl+F.) were used as controls, and strain fermentation liquid was used for root irrigation and inoculation of Fusarium oxysporum fermentation liquid (Sneb2538+F.) as treatment. 10mL of Fusarium oxysporum fermentation liquid (concentration of about 1×10 8 CFU / mL, and each seedling was treated by irrigating the root with 10 mL of the fermentation liquid (concentration of about 1×10 8 CFU / mL), and the control was irrigated with an equal amount of sterile water or culture medium (LB broth) or agent (1.8% thiophanate methyl) per seedling. Each treatment was repeated 3 times, with 5 seedlings per repeat, and they were placed completely randomly. After 30 days of cultivation, the disease condition of the plants was observed, and the disease index and control effect were calculated.

[0074] The grading standard for cucumber wilt disease is as follows: Grade 0, no disease; Grade 1, the wilting area of ​​leaves or stems accounts for 1 / 4 or less of the whole plant; Grade 2, the wilting area of ​​leaves or stems accounts for 1 / 2 of the whole plant; Grade 3, the wilting area of ​​leaves or stems accounts for 3 / 4 of the whole plant; Grade 4, the whole plant wilts; Grade 5, complete death.

[0075]

[0076]

[0077] 2. Experimental Results

[0078] Table 2 Effect of fermentation liquid root irrigation on the prevention of cucumber wilt

[0079]

[0080]

[0081] Note: The data in the table are mean ± standard deviation. Different letters in the same column indicate significant differences at the P < 0.05 level as tested by Duncan's method.

[0082] As shown in Table 2, under potted conditions, 30 days after inoculation, the disease index of cucumber plants treated with sterile water, LB and 1.8% thiophanate-methyl control was 62.22, 55.56 and 44.44 respectively. After the cucumber seedlings were treated with the fermentation liquid of Sneb2538 strain, the disease index of cucumber was significantly lower than the above control, and the control efficiency was 42.86%. Therefore, under potted conditions, marine sediment Bacillus Sneb2538 can effectively prevent and control cucumber wilt.

[0083] Example 5: Effect of the fermentation liquid of marine sediment Bacillus Sneb2538 on the growth of cucumber plants.

[0084] 1. Experimental Methods

[0085] The fermentation broth of marine sediment Bacillus Sneb2538 was prepared according to the above method and set aside.

[0086] The cucumber variety is Zhongnong No. 6, and the seeds are disinfected by warm water soaking method (55℃ soaking for 30min). The disinfected seeds are sown in seedling trays filled with nutrient soil (sand volume: seedling medium volume = 1:1). The nutrient soil is sterilized at 160℃ for 180min before sowing, and placed in a greenhouse with a temperature of 25℃, 16h light and 8h dark for about two weeks. After culturing to the two-leaf and one-heart stage, the yellowed seedlings are transplanted into pots (9.5cm×11.5cm), with one seedling in each container for standby use.

[0087] The following treatments were designed: 10 mL of sterile water or culture medium (LB broth) was irrigated to the roots of each seedling as a control; 10 mL of the fermentation liquid of the strain (concentration of about 1×10 8 CFU / mL) was used as treatment. Each treatment was repeated 3 times, and each repeat had 3 seedlings, which were placed completely randomly. After 30 days of cultivation, the plant height, plant fresh weight, root length and root fresh weight of cucumber plants were investigated.

[0088] 2. Experimental Results

[0089] Table 3 Effects of root irrigation with marine sediment Bacillus Sneb2538 on the growth of cucumber plants

[0090] deal with Plant height / cm Plant fresh weight / g Root length / cm Root fresh weight / g <![CDATA[ddH2O]]> 20.86±0.98b 8.55±0.50b 15.48±0.70b 2.39±0.17a LB 18.75±0.96c 5.41±0.64c 18.37±0.93a 2.11±0.33b Sneb2538 25.32±1.48a 15.29±0.86a 17.67±0.79a 2.64±0.20a

[0091] Note: The data in the table are mean ± standard deviation. Different letters in the same column indicate significant differences at the P < 0.05 level as tested by Duncan's method.

[0092] The results are shown in Table 3. Under potted conditions, after the cucumber seedlings were treated with Sneb2538 fermentation liquid, the plant height was 25.32 cm, the plant fresh weight was 15.29 g, the root length was 17.67 cm, and the root fresh weight was 2.64 g; compared with the LB control, the plant height, plant fresh weight, and root fresh weight were significantly increased, and there was no significant difference in root length. Therefore, under potted conditions, marine sediment Bacillus Sneb2538 effectively promoted the growth of cucumber plants.

[0093] Example 6: Field efficacy experiment of marine sediment Bacillus Sneb2538 fermentation liquid.

[0094] 1. Experimental Methods

[0095] The fermentation broth of marine sediment Bacillus Sneb2538 was prepared according to the above method and set aside.

[0096] The cucumber variety is Zhongnong No. 6, and the seeds are disinfected by soaking in warm water (55℃ for 30 minutes). The disinfected seeds are sown in seedling trays filled with nutrient soil (sand volume: seedling medium volume = 1:1). The nutrient soil is sterilized at 160℃ for 180 minutes before sowing, and placed in a greenhouse with a temperature of 25℃, 16h light and 8h dark for about two weeks. After being cultivated to the two-leaf and one-heart stage, they are transplanted to the field where cucumber wilt disease occurs.

[0097] The following treatments were designed for the experiment: when transplanting, sterile water, culture medium, and agent (1.8% thiophanate methyl) were used as controls, and each seedling was irrigated with 10 mL of sterile water or culture medium (LB broth) or agent (1.8% thiophanate methyl). Bacterial strain fermentation liquid was used as a treatment, and each seedling was irrigated with 10 mL of the fermentation liquid (concentration of about 1×10 8 CFU / mL). After 30 days of cultivation, the physiological indicators of cucumber plants such as plant height, root length, root fresh weight, and plant fresh weight were measured, the disease index was investigated, and the control effect was calculated. Disease index grading standard: 0, no disease; 1, the wilting area of ​​leaves or stems accounts for 1 / 4 or less than 1 / 4 of the whole plant; 2, the wilting area of ​​leaves or stems accounts for 1 / 2 of the whole plant; 3, the wilting area of ​​leaves or stems accounts for 3 / 4 of the whole plant; 4, the whole plant wilts; 5, complete death.

[0098]

[0099]

[0100] 2. Experimental Results

[0101] Table 4 Field efficacy of marine sediment Bacillus Sneb2538 fermentation liquid against cucumber wilt

[0102] deal with Root length / cm Root fresh weight / g Plant fresh weight / g Plant height / cm Disease index Prevention effect / % <![CDATA[ddH2O]]> 8.49±0.83b 2.24±0.49a 150.50±11.26c 139.17±3.2c 93.06±6.36a LB 9.04±0.38b 2.82±0.09a 165.67±7.45b 159.00±6.03b 87.50±4.17a 5.97 1.8% Thiophanate Methyl 8.52±0.32b 2.53±0.16a 160.33±8.66bc 146.33±4.63bc 58.33±7.22b 37.31 Sneb2538 15.30±0.80a 2.66±0.74a 234.83±13.11a 230.50±19.76a 40.28±2.41c 56.72

[0103] Note: The data in the table are mean ± standard deviation. Different letters in the same column indicate significant differences at the P < 0.05 level as tested by Duncan's method.

[0104] As shown in Table 4, under field conditions, the disease index of cucumber plants after sterile water and LB broth treatment was 93.06 and 87.50, respectively; after irrigating cucumber seedlings with methyl thiophanate and Sneb2538 fermented liquid, the disease index was 58.33 and 40.28, and the control efficiency was 37.31% and 56.72%, respectively. The disease index and control efficiency after Sneb2538 fermented liquid treatment were significantly lower than those after sterile water, LB broth treatment and methyl thiophanate, indicating that marine sediment Bacillus Sneb2538 effectively prevents and controls cucumber wilt. At the same time, compared with sterile water, LB broth and methyl thiophanate treatment, the root length, plant fresh weight and plant height of cucumber seedlings after Sneb2538 fermented liquid irrigated roots were significantly increased, and there was no significant difference in root fresh weight, indicating that marine sediment Bacillus Sneb2538 effectively promotes plant growth.

[0105] Therefore, under field conditions, marine sediment Bacillus Sneb2538 can effectively control cucumber wilt and promote plant growth.

[0106] Although preferred embodiments of the present invention have been described, additional changes and modifications may occur to these embodiments once those skilled in the art are aware of the basic inventive concepts.

[0107] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include these modifications and variations.

Claims

1. A strain of Cytobacillus oceanisediminis Sneb2538, characterized in that: The marine sediment Bacillus Sneb2538 was deposited in the General Microbiology Center of the China Microbiological Culture Collection Administration on August 12, 2024, with a deposit number of CGMCC No.31569 and a classification name of Cytobacillus oceanisediminis.

2. A fermentation liquid obtained by fermenting the marine sediment Bacillus Sneb2538 according to claim 1, characterized in that: The fermentation liquid is inoculated with marine sediment Bacillus Sneb2538 into a liquid culture medium and cultured until the strain concentration is 1×10 7 CFU / mL~1×10 8 CFU / mL obtained.

3. A method for preparing the fermentation liquid according to claim 2, characterized in that: The preparation steps of the fermentation liquid are as follows: activating the marine sediment Bacillus Sneb2538 and inoculating it into a liquid fermentation medium at a temperature of 26°C to 28°C and 150 r·min -1 ~200r·min -1 Shake the culture for 1.5 to 2 days to obtain the fermentation liquid.

4. The method for preparing the fermentation liquid according to claim 3, characterized in that: The liquid fermentation medium is LB broth medium.

5. The method for preparing the fermentation liquid according to claim 3, characterized in that: The preparation steps of the fermentation liquid are as follows: activating the marine sediment Bacillus Sneb2538 and inoculating it into the liquid fermentation medium at a temperature of 28°C and 200 r·min -1 The culture was shaken for 2 days to obtain the fermentation liquid.

6. Use of the marine sediment Bacillus Sneb2538 of claim 1 or the fermentation liquid of claim 2 in cucumber cultivation, characterized in that: The marine sediment Bacillus Sneb2538 or fermentation liquid is used for preventing and controlling cucumber wilt and promoting the growth of cucumber plants.

7. The use according to claim 6, characterized in that: The marine sediment Bacillus Sneb2538 is used to inhibit the cucumber wilt pathogen Fusarium oxysporum f.sp.cucumerinum Owen.

8. The use according to claim 6, characterized in that: The marine sediment Bacillus Sneb2538 is used to inhibit the germination of Fusarium oxysporum spores.

9. The use according to claim 6, characterized in that: The fermentation liquid of the marine sediment Bacillus Sneb2538 is used to treat cucumber seedlings through root irrigation to prevent and control cucumber wilt.

10. The use according to claim 6, characterized in that: The method of promoting the growth of cucumber plants includes: increasing the plant height, plant fresh weight and root fresh weight of the cucumber plants.

Images