Bacillus pumilus with salt-tolerant and growth-promoting functions and application of bacillus pumilus

Abstract

The invention relates to the technical field of functional microorganism screening and application, and particularly provides bacillus pumilus with salt-tolerant and growth-promoting functions and application of the bacillus pumilus. The preservation number of the bacillus pumilus is CCTCC NO: M20231590, and the bacillus pumilus can effectively relieve crop salt damage, promote crop growth, increase crop yield, improve the harm of increasingly serious land salinization to agricultural planting and ensure the crop yield and quality.

Description

Technical Field

[0001] The invention relates to the technical field of functional microorganism screening and application, and in particular to a strain of Bacillus pumilus with salt-resistant growth-promoting function and application thereof. Background Art

[0002] Saline soil refers to a general term for various types of soils with high concentrations of soluble salt ions in the soil, which have adverse effects on the physical and chemical properties of the soil and plant growth. Soil salinization can cause the soil to exhibit undesirable properties and deteriorate in quality, seriously affecting agricultural production. There are many factors that affect the formation of soil salinization. Natural factors are the main cause of soil salinization, but human activities can also cause soil salinization. Among them, unreasonable irrigation and irrigation methods that emphasize irrigation over drainage during agricultural production, excessive fertilization and unscientific crop rotation methods can all lead to salinization of cultivated soil.

[0003] Soil salinization can cause changes in soil properties, such as soil compaction, poor air and water permeability, low nutrient utilization, reduced organic matter content, decreased soil fertility, and reduced soil enzyme activity, thus affecting the activities of soil microorganisms and the transformation of soil organic matter. Salt stress is one of the main abiotic stresses that affect plant growth and development, and has a serious impact on crop yield, quality and benefits. The increase in soil salt concentration reduces the ability of plants to absorb water, causing physiological dehydration in plants, which in turn leads to dwarfing, slow growth, yellowing and wilting of leaves, and even death.

[0004] At present, the treatment and control of saline-alkali land has become a common concern. The current measures for improving saline-alkali land mainly include agricultural measures, chemical measures, physical measures, and biological measures. Among them, agricultural engineering measures, chemical measures, and physical measures have more or less some disadvantages, such as large engineering volume, rising groundwater, and salt return phenomenon, which can only improve the surface saline soil in the short term. The microbial resources contained in saline soil are very rich, and they are highly responsive to soil components, physical and chemical properties, and microenvironment. The use of microorganisms to repair saline-alkali land has received widespread attention. During their life activities, beneficial microorganisms produce a large number of secondary metabolites, organic acids, which release slow-release nitrogen, phosphorus, and potassium in the soil. It promotes plant growth through nitrogen fixation, potassium dissolution, and phosphorus dissolution; at the same time, it produces iron carriers, IAA and ACC deaminase, and enhances plant resistance. Studies have shown that microbial agents can change the physical and chemical properties of soil and the community structure of soil microorganisms, increase nutrients in the soil, and promote plant growth. Microbial remediation has the advantages of no pollution, low investment, economy, high efficiency, and a wide range of applications.

[0005] Screening salt-tolerant microbial strains with excellent performance from saline-alkali soil is of great significance for the promotion and application of microbial agents in the fields of soil improvement and restoration, improving plant salt tolerance, and promoting plant growth under saline-alkali stress. It is also a research hotspot in this field. Summary of the invention

[0006] The purpose of the present invention is to provide a strain of Bacillus pumilus with salt-tolerant growth-promoting function and its application. The Bacillus pumilus can effectively alleviate crop salt damage, promote crop growth, increase crop yield, improve the increasingly serious harm of land salinization to agricultural planting, and ensure crop yield and quality.

[0007] On the one hand, the present invention provides a Bacillus pumilus, which is Bacillus pumilus BP67 (Bacillus pumilus BP67), which was deposited in the China Type Culture Collection of Wuhan University, Wuhan, China on September 4, 2023, with a deposit number of CCTCC NO: M20231590.

[0008] On one hand, the present invention provides the use of the Bacillus pumilus BP67 strain in the production of bio-fertilizer.

[0009] In one aspect, the present invention provides application of the Bacillus pumilus BP67 strain in improving saline-alkali land.

[0010] The invention also provides a biofertilizer, comprising Bacillus pumilus BP67.

[0011] The biofertilizer further comprises any one or more combinations of Bacillus, Pseudomonas, Agrobacterium, nitrogen-fixing bacteria, Rhizobium, Penicillium, Aspergillus, Rhizopus, and Streptomyces.

[0012] The amount of live bacteria of Bacillus pumilus BP67 in the biofertilizer is not less than 10 9 CFU / g.

[0013] The invention also provides application of the biological fertilizer in agricultural planting.

[0014] The application amount of the biological fertilizer is 1-5 kg / mu.

[0015] The Bacillus pumilus BP67 screened by the present invention has strong tolerance to high-salt environment, can grow on a culture medium with a concentration of 18% NaCl, can produce high amounts of indoleacetic acid (IAA) and extracellular polysaccharides (EPS), and after 48 hours of fermentation culture, the IAA content in the fermentation supernatant is as high as 14.8 mg / L, and after 72 hours of fermentation culture, the EPS yield is 0.48 g / g. Bacillus pumilus BP67 also has the ability to produce ACC deaminase, which is beneficial to inhibiting the synthesis of ethylene in plants, reducing the sensitivity of plants to adversity, and improving the stress resistance of plants.

[0016] Bacillus pumilus BP67 has no side effects on wheat seed germination, and can effectively promote seedling growth, increase enzyme activity in wheat rhizosphere soil, and promote crop absorption and utilization of nutrients such as carbon, nitrogen, and phosphorus. Compared with the control group, the wheat seed germination rate of treatment group 1 with the addition of Bacillus pumilus BP67 bacterial solution was 100%, and the plant height, root length, aboveground fresh weight, and underground fresh weight of wheat seedlings increased by 25.0%, 14.6%, 10.5%, and 14.3%, respectively, with better growth; the activities of sucrase, urease, and alkaline phosphatase in the wheat rhizosphere soil increased by 92.9%, 3.5%, and 7.1%, respectively, achieving unexpected technical effects.

[0017] Bacillus pumilus BP67 can effectively reduce the effects of salt stress on seed germination and emergence, and promote the normal growth of crops under salt stress conditions. Compared with the salt stress treatment group 2, the germination rate of wheat seeds in the treatment group 3 with the addition of Bacillus pumilus BP67 bacterial solution increased by 26.7%, and the plant height, root length, aboveground fresh weight, and underground fresh weight of wheat seedlings increased by 30.9%, 90.9%, 47.4%, and 77.8%, respectively; the activities of sucrase, urease, and alkaline phosphatase in the rhizosphere soil of wheat increased by 14.2%, 37.7%, and 7.7%, respectively, with very significant effects.

[0018] Bacillus pumilus BP67 can be widely used in saline-alkali land crop planting, which can significantly increase the emergence rate, promote crop growth, and improve quality and yield. Compared with the control group, the corn emergence rate and yield of the treatment group treated with Bacillus pumilus BP67 powder increased by 5.1% and 12.2% respectively; the plant height, plant weight and yield of tomatoes increased by 15.6%, 23.7% and 12.57% respectively, achieving unexpected technical effects.

[0019] The Bacillus pumilus BP67 provided by the present invention has the effects of alleviating salt damage to crops, promoting crop growth, and increasing crop yield, and can effectively improve the increasingly serious harm of land salinization to agricultural planting, and ensure the yield and quality of crops. Bacillus pumilus BP67 can also be added to fertilizers such as organic fertilizers and chemical fertilizers, and combined with any one or more of other Bacillus, Pseudomonas, Agrobacterium, nitrogen-fixing bacteria, rhizobia, Penicillium, Aspergillus, Rhizopus, and Streptomyces, and has broad application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 is the colony morphology of Bacillus pumilus BP67;

[0021] Figure 2 is the protein spectrum of Bacillus pumilus BP67;

[0022] Figure 3 This is a comparison chart of the effects of Bacillus pumilus BP67 on wheat seedling emergence;

[0023] Figure 4 This is a comparison chart of the growth-promoting effect of Bacillus pumilus BP67 on wheat;

[0024] Figure 5 This is a comparison chart of the effects of Bacillus pumilus BP67 on corn cultivation. DETAILED DESCRIPTION

[0025] For the specific methods or materials used in the embodiments, those skilled in the art can make conventional replacement selections based on the technical ideas of the present invention and according to existing technologies, and are not limited to the specific descriptions of the embodiments of the present invention.

[0026] The present invention is further described below in conjunction with specific embodiments.

[0027] Example 1 Isolation and screening of strains

[0028] 1.1 Sample source: Suaeda salsa and rhizosphere soil from Qingdao tidal flat.

[0029] 1.2 Isolation of salt-tolerant strains

[0030] Take 10g soil sample and put it into 90mL sterile water and shake it at 180r / min for 30min to obtain a sample mixture. The sample mixture was gradient diluted and then applied to 10% NaCl LB solid culture medium to separate the salt-tolerant strains in the sample mixture, and cultured at 37°C for 48h-96h. Colonies of different shapes, colors and sizes were selected for multiple purifications to obtain 6 strains of bacteria, which were numbered NY1-NY6 and stored in liquid glycerol.

[0031] 1.3 Determination of salt tolerance of strains

[0032] By continuously increasing the salinity of the culture medium, salt-tolerant strains were screened. LB culture medium with NaCl concentrations of 10%, 12%, 14%, 16% and 18% was prepared; the 6 strains isolated and purified above were inoculated into the plate and cultured at 37°C. Whether the strains grew out was used as the criterion for judging whether the strains were salt-tolerant and alkali-tolerant, and the strains with the best salt-tolerant and alkali-tolerant ability were screened. The results are shown in Table 1.

[0033] Table 1 Salt tolerance of each strain

[0034]

[0035] Note: “+” indicates that the strain grew, and “-” indicates that the strain did not grow.

[0036] From the results in Table 1, it can be seen that different strains grow differently in different salinity culture media, among which strain NY6 has the strongest salt tolerance and can grow in a culture medium with a salinity of 18% NaCl.

[0037] The applicant named strain NY6 as BP67 and further evaluated it.

[0038] Example 2 Identification of BP67 strain

[0039] 2.1 Colony morphology identification

[0040] The colonies of BP67 strain on LB medium are as follows Figure 1 As shown, it is white in color, round, with a smooth surface, neat edges, raised and sticky; the Bacillus bacteria are straight rod-shaped and can produce spores, which are round and positive under Gram staining microscopy.

[0041] 2.2 16S rRNA molecular identification

[0042] The genome of strain BP67 was extracted using a kit, and then the 16S rRNA was amplified using the genome as a template using specific primers 27F and 1492R.

[0043] 27F: 5'-AGAGTTTGATCATGGCTCAG-3';

[0044] 1492R: 5'-TAGGGTTACCTTACGACTT-3'.

[0045] The PCR system included: 0.7 μl 27F, 0.7 μl 1492R, 4 μl template DNA, 17.5 μl SuperMiX and 12.1 μl water. The PCR reaction conditions were set as follows: (1) 94°C for 5 min; (2) 94°C pre-denaturation for 30 s; (3) 55°C for 30 s; (4) 72°C for 1 min; perform steps (2) to (4) for 35 cycles; (5) 72°C for 10 min. The amplified PCR product was subjected to 1% agarose gel electrophoresis, and the results showed that the size of the PCR product was about 1500 bp, which met the requirements.

[0046] The PCR amplification product was sent to a sequencing company for sequencing, and the obtained sequence SEQ ID NO: 1 was subjected to BLAST comparison in the NCBI database, which showed the highest similarity to Bacillus pumilus. Therefore, the BP67 strain was preliminarily determined to be Bacillus pumilus.

[0047] 2.3 MALDI-TOF-MS protein spectrum identification

[0048] Take a small amount of BP67 single colony and apply it on the target plate in the form of a film; add 1μL of the lysis solution in the mass spectrometry sample pretreatment kit and dry it naturally at room temperature; add 1μL of the matrix solution in the mass spectrometry sample pretreatment kit to cover the sample and dry it naturally at room temperature; put the sample target into the mass spectrometer for identification. The identification results show that the BP67 strain is Bacillus pumilus, and its protein spectrum peak is as follows Figure 2 shown.

[0049] In summary, the applicant used two molecular biological methods, 16S rRNA identification and MALDI-TOF-MS protein spectrum identification, to identify strain BP67, and the identification results were consistent. Combined with the colony morphology of strain BP67, the applicant determined that the strain was Bacillus pumilus and named it Bacillus pumilus BP67.

[0050] The applicant deposited the above-mentioned Bacillus pumilus BP67 (Bacillus pumilus BP67) with the China Type Culture Collection of Wuhan University, Wuhan, China on September 4, 2023, with the deposit number CCTCC NO: M20231590.

[0051] Example 3 Evaluation of salt tolerance and growth-promoting properties of Bacillus pumilus BP67

[0052] Salt-tolerant microorganisms can adapt to high-salt environments by forming extracellular polysaccharides (EPS) and biofilms, and directly regulate and alleviate plant salt stress by producing plant hormone signals IAA and ACC deaminase, thereby improving the acquisition of nutrients and other resources and promoting the healthy growth of crops.

[0053] 3.1 Ability to produce indoleacetic acid (IAA)

[0054] Bacillus pumilus BP67 was inoculated with 5% inoculum into LB liquid culture medium containing 5% NaCl, and cultured at 30°C and 180r / min for 48h; the fermentation broth was centrifuged at 10000rpm for 10min to remove the bacteria; 2mL of supernatant and equal volumes of Salkowski reagent were mixed, and the mixture was placed in a dark place. After 30min, the absorbance of the solution at a wavelength of 530nm was measured, and the IAA content in the fermentation broth was calculated according to the standard curve of IAA.

[0055] The results showed that after 48 hours of fermentation of Bacillus pumilus BP67, the IAA content in the fermentation supernatant was as high as 14.8 mg / L. The IAA secreted by Bacillus pumilus BP67 can promote the synthesis of IAA in plants, thereby promoting the growth of crops.

[0056] 3.2 Extracellular polysaccharide (EPS) production capacity

[0057] Inoculate Bacillus pumilus BP67 into EPS-producing fermentation medium at an inoculation rate of 5%, and culture at 30°C for 72 hours; take 10 mL of the strain fermentation liquid, centrifuge at 4000 r / min for 15 minutes, and collect the bacteria; dry the bacteria at 105°C to constant weight; mix the fermentation supernatant with 30 mL of 95% ethanol, and place it at 4°C overnight for alcohol precipitation; centrifuge the mixture at 4000 r / min for 30 minutes, and collect the precipitate; dry the precipitate at 105°C to constant weight to obtain EPS.

[0058] The calculation formula of strain EPS production is as follows:

[0059] EPS yield (g / g) = (fermentation broth EPS dry weight - culture medium EPS dry weight) / strain dry weight.

[0060] The results showed that the EPS production of Bacillus pumilus BP67 was 0.48 g / g after 72 h of fermentation.

[0061] 3.3 Capacity to produce 1-aminocyclopropane-1-carboxylic acid (ACC) deaminase

[0062] Prepare 5g / L ACC solution and ammonium sulfate solution respectively, filter and sterilize. Add 5g / L ACC solution to the sterilized SM liquid medium, so that the final concentration of ACC in the medium is 0.5g / L, which is SMA medium. Similarly, add 5g / L ammonium sulfate solution to the SM medium, so that the final concentration of ammonium sulfate is 0.5g / L, which is SMN medium. Inoculate the strain to the liquid LB medium and culture for 12-24h, centrifuge at 5000rpm and 4℃ for 10min, pour out the supernatant, collect the bacteria, suspend with sterile water, and add 0.5ml of bacterial solution to the three liquid culture media of SM, SMA, and SMN. Culture for 12h at 28℃ and 180r / min in a shaking table, and determine whether it has the ability to produce ACC deaminase by measuring the absorbance values ​​of the three different culture media at 535nm. The strain that produces ACC deaminase cannot grow in SM medium, but can grow stably in SMA and SMN medium.

[0063] The results showed that Bacillus pumilus BP67 only grew a small amount in nitrogen-free SM medium, but could grow in SMA medium with ACC as the only nitrogen source, and its growth was stronger than that in SM medium, which could exclude the influence of nitrogen fixation, indicating that Bacillus pumilus BP67 has the ability to produce ACC deaminase. ACC deaminase can decompose ACC into ammonia and α-ketobutyric acid, thereby inhibiting the synthesis of ethylene in plants, reducing the sensitivity of plants to adversity, and improving the resistance of plants to adversity.

[0064] Example 4 Effect of Bacillus pumilus BP67 on wheat seed germination under salt stress

[0065] 4.1 Preparation of bacterial culture

[0066] The activated Bacillus pumilus BP67 was selected and inoculated into the nutrient broth medium, and cultured at 37°C and 220 r / min for 18 h to obtain a viable bacterial count of 10 8 -10 9 CFU / ml of bacterial solution for future use.

[0067] 4.2 Hydroponic experiment

[0068] The wheat seeds were surface sterilized with 10% sodium hypochlorite for 30 minutes, rinsed with clean water 3 times and sown in hydroponic bottles, with 15 seeds sown in each bottle. The hydroponic system was 700ml, and the specific groups were as follows:

[0069] Control group (CK): 700 ml of water;

[0070] Treatment group 1: 100ml BP67 bacterial solution + 600ml water

[0071] Treatment group 2: 100 ml water + 600 ml 100 mmol / L NaCl aqueous solution;

[0072] Treatment group 3: 100 ml BP67 bacterial solution + 600 ml 100 mmol / L NaCl aqueous solution

[0073] Culture in a 25℃ incubator, observe and record regularly, count the emergence of seeds after 7 days, and measure the plant height.

[0074] Table 2 Effects of Bacillus pumilus BP67 on wheat germination

[0075] Grouping Processing Number of seedlings (plants) Seedling rate Plant height CK Shimizu 15 100％ 8.8cm Treatment Group 1 BP67 bacterial liquid 15 100％ 10.2cm Treatment Group 2 NaCl aqueous solution 11 73.3％ 5.6cm Treatment Group 3 NaCl aqueous solution + BP67 bacterial solution 15 100％ 7.5cm

[0076] From Table 2 and Figure 3 The results showed that compared with the control group, the wheat seed germination rate of treatment group 1 with the addition of Bacillus pumilus BP67 solution was 100%, and the wheat seedlings grew better, with the plant height increased by 15.9%. This shows that Bacillus pumilus BP67 has no side effects on seed germination and can effectively promote seedling growth.

[0077] Salt stress conditions can seriously affect seed germination. The germination rate of wheat seeds in treatment group 2 with the addition of NaCl aqueous solution was only 73.3%, and the plant height was 36.4% lower than that of the control group. Compared with treatment group 2, the germination rate of wheat seeds in treatment group 3 with the addition of Bacillus pumilus BP67 bacterial solution increased by 26.7% and the plant height increased by 33.9%, which was a very significant effect. This shows that Bacillus pumilus BP67 can effectively reduce the impact of salt stress on seed germination and germination, promote the healthy growth of wheat, and achieve unexpected technical results.

[0078] Example 5 Evaluation of the growth-promoting effect of Bacillus pumilus BP67 on wheat seedlings under salt stress

[0079] 5.1 Preparation of bacterial culture

[0080] The activated Bacillus pumilus BP67 was selected and inoculated into the nutrient broth medium, and cultured at 37°C and 220 r / min for 18 h to obtain a viable bacterial count of 10 8 -10 9 CFU / ml of bacterial solution for future use.

[0081] 5.2 Potted plant experiment

[0082] Disinfect the surface of wheat seeds with 10% sodium hypochlorite for 30 minutes, rinse with clean water 3 times, and then sow in seedling trays for germination. After germination, select seedlings with the same growth and health and transplant them into pots. The soil in the pots is treated as follows:

[0083] Control group (CK): add 150 ml of water;

[0084] Treatment group 1: add 100 ml BP67 bacterial solution + 50 ml water;

[0085] Treatment group 2: add 50 ml of 200 mmol / L NaCl aqueous solution + 100 ml of water;

[0086] Treatment group 3: Add 50 ml of 200 mmol / L NaCl aqueous solution and 100 ml of BP67 bacterial solution;

[0087] Three parallels were set up in each group and cultured in a 25℃ incubator. Samples were taken after 10 days to measure plant growth indicators and enzyme activities in the wheat rhizosphere soil. The activities of alkaline phosphatase, urease and sucrase in the wheat rhizosphere soil were determined by indophenol colorimetry, ninhydrin colorimetry and 3,5-dinitrosalicylic acid colorimetry, respectively.

[0088] 5.3 Experimental Results

[0089] Table 3 Effects of different treatment groups on the growth of wheat seedlings

[0090] category Processing Plant height Root length Fresh weight of aboveground parts Fresh weight of underground part CK Shimizu 12cm 4.1cm 3.8g 2.1g Treatment Group 1 BP67 bacterial liquid 15 cm 4.8cm 4.2g 2.4g Treatment Group 2 NaCl aqueous solution 6.8 cm 2.2cm 1.9g 0.9g Treatment Group 3 NaCl aqueous solution + BP67 bacterial solution 8.9 cm 4.2cm 2.8g 1.6g

[0091] From Table 3 and Figure 4 The results showed that compared with the control group, the plant height, root length, fresh weight of aboveground part and fresh weight of underground part of wheat seedlings in treatment group 1 with Bacillus pumilus BP67 solution increased by 25.0%, 14.6%, 10.5% and 14.3% respectively, and the wheat seedlings grew better. This shows that Bacillus pumilus BP67 can effectively promote the growth of wheat seedlings with significant effect.

[0092] Salt stress can inhibit the growth of wheat. The plant height, root length, fresh weight of aboveground part and fresh weight of underground part of wheat seedlings in treatment group 2 with addition of NaCl aqueous solution were significantly lower than those in the control group. Compared with treatment group 2, the plant height, root length, fresh weight of aboveground part and fresh weight of underground part of wheat seedlings in treatment group 3 with addition of Bacillus pumilus BP67 solution increased by 30.9%, 90.9%, 47.4% and 77.8%, respectively. This shows that Bacillus pumilus BP67 can effectively reduce the inhibitory effect of salt stress and promote the recovery of normal growth of crops.

[0093] Table 4 Effects of different treatments on soil enzyme activities

[0094]

[0095] The results in Table 4 show that compared with the control group, the activities of sucrase, urease and alkaline phosphatase in the rhizosphere soil of wheat in treatment group 1 with the addition of Bacillus pumilus BP67 solution increased by 92.9%, 3.5% and 7.1%, respectively. Salt stress can significantly reduce the activities of the above three enzymes, and the activities of the above three enzymes in the rhizosphere soil of wheat in treatment group 2 all decreased significantly. Compared with treatment group 2, the activities of sucrase, urease and alkaline phosphatase in the rhizosphere soil of wheat in treatment group 3 with the addition of Bacillus pumilus BP67 solution increased by 14.2%, 37.7% and 7.7%, respectively, and the effect was very significant.

[0096] Sucrase participates in the soil organic carbon cycle and can effectively improve the utilization of soil carbon; urease is a key enzyme in soil nitrogen transformation, and the increase of its activity can promote the transformation of effective nitrogen; soil phosphatase plays an important role in plant phosphorus nutrition by mediating the release of inorganic phosphorus from organically bound phosphorus. It can be seen that Bacillus pumilus BP67 can effectively increase soil enzyme activity, promote the absorption and utilization of nutrients such as carbon, nitrogen, and phosphorus by crops, and promote the normal growth of crops under salt stress conditions.

[0097] Example 6 Application of Bacillus pumilus BP67 in corn cultivation in saline-alkali land

[0098] 6.1 Experimental location and crop varieties:

[0099] The saline-alkali land planting base in the Agricultural High-tech Zone of Dongying City, Shandong Province, the corn variety is Meikang 68.

[0100] 6.2 Field experiment:

[0101] The experimental area is 4 mu, divided into 2 groups, each group has a treatment area of ​​2 mu, and the soil salinity of the experimental field is 3‰. The treatment group uses Bacillus pumilus BP67 powder (10 billion cfu / g), and 1kg / mu is applied as base fertilizer when turning the soil, and 1kg / mu is applied by watering 20 days later; the control group (CK) is routinely fertilized without bacterial agents. The field management measures are consistent. The emergence rate is investigated during the emergence period, and the growth indicators and yield are investigated during the harvest period.

[0102] 6.3 Results

[0103] Table 5 Application effect of Bacillus pumilus BP67 on corn

[0104]

[0105] From Table 5 and Figure 5 The experimental results show that compared with the control group, the corn germination rate in the treatment group treated with Bacillus pumilus BP67 powder increased by 5.1% and the yield increased by 12.2%. This shows that Bacillus pumilus BP67 can effectively promote the germination and growth of corn in saline-alkali land, achieving unexpected technical effects.

[0106] Example 7 Application of Bacillus pumilus BP67 in tomato cultivation in saline-alkali land

[0107] 7.1 Experimental location and crop varieties:

[0108] Tomatoes are grown in a greenhouse in Liuhe Street, Dongying City, Shandong Province. The variety is Provence.

[0109] 7.2 Field Experiments:

[0110] The soil salinity of the experimental site was 2‰, the experimental plot area was 10m×8m, and there were 10 rows of tomatoes in each experimental plot, about 400±20 plants. The treatment group was treated with 10 billion cfu / g of BP67 powder, and the rest of the fertilizer, water and medicine management remained the same. Each treatment group was repeated 3 times, with a total of 9 experimental plots, and the specific groups were as follows:

[0111] Control group (CK): no bacterial agent was used, and water was used;

[0112] Treatment group 1: Apply the fertilizer in the planting water after transplanting and 10 days after transplanting, with each application amount of 500g / mu;

[0113] Treatment group 2: Apply the fertilizer in the planting water after transplanting and 10 days after transplanting, with each application rate of 1kg / mu;

[0114] During the growth period of tomatoes, the plant height, plant weight and yield were investigated and counted, the yield increase effect was calculated, samples were taken to test the soluble sugar and VC content of tomatoes, and the impact on quality was evaluated.

[0115] 7.3 Experimental Results

[0116] Table 6 Application effect of Bacillus pumilus BP67 on tomatoes

[0117]

[0118] It can be seen from the experimental results in Table 6 that in tomato cultivation in saline-alkali land, the application of Bacillus pumilus BP67 powder can significantly promote the growth of tomatoes. The plant height, plant weight and yield of tomatoes in the treatment group were increased by 15.6%, 23.7% and 12.57% respectively compared with the control group; at the same time, the quality of tomatoes in the treatment group was significantly improved, and the soluble sugar and VC contents were increased by 13.3% and 15.8% respectively, achieving unexpected technical effects.

[0119] In summary, the Bacillus pumilus BP67 provided by the present invention can be widely used in saline-alkali land crop planting, has the effect of alleviating crop salt damage, promoting crop growth, and increasing crop yield, effectively improving the increasingly serious land salinization and alkali damage to agricultural planting, and ensuring crop yield and quality. Bacillus pumilus BP67 can also be added to organic fertilizers, chemical fertilizers and other fertilizers for use, and combined with any one or more of other Bacillus, Pseudomonas, Agrobacterium, nitrogen-fixing bacteria, rhizobia, Penicillium, Aspergillus, Rhizopus, and Streptomyces, and has broad application prospects.

Claims

1. A Bacillus pumilus, characterized in that The deposit number of the Bacillus pumilus is CCTCC NO: M20231590.

2. Application of Bacillus pumilus according to claim 1 in biofertilizer production.

3. Use of the Bacillus pumilus described in claim 1 in improving saline-alkali land.

4. A biological fertilizer, characterized in that: The biological fertilizer comprises the Bacillus pumilus described in claim 1.

5. The biofertilizer according to claim 4, characterized in that The biological fertilizer further comprises any one or more combinations of Bacillus, Pseudomonas, Agrobacterium, nitrogen-fixing bacteria, Rhizobium, Aspergillus, Rhizopus, and Streptomyces.

6. The biofertilizer according to claim 4 or 5, characterized in that: The amount of live bacteria of Bacillus pumilus in the biofertilizer is not less than 10 9 CFU / g.

7. Use of the biofertilizer according to any one of claims 4 to 6 in agricultural planting.

8. The use according to claim 7, characterized in that The application amount of the biological fertilizer is 1-5 kg / mu.

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