Halomonas sp. SX-J3 and application thereof in saline alkali soil environment

Abstract

The invention belongs to the technical field of microorganisms, and particularly relates to Halomonas sp. SX-J3 and application thereof in a saline alkali soil environment. The invention provides a Halomonas sp. SX-J3, and the preservation number is CGMCC (China General Microbiological Culture Collection Center) NO.31722. The halomonas SX-J3 provided by the invention has relatively strong saline-alkaline resistance, can promote the germination rate of seeds (such as soybean seeds) in a saline-alkaline environment and promote the growth of plants in the saline-alkaline environment, and can effectively reduce the alkalinity of the saline-alkaline soil and degrade the concentration of water-soluble sodium ions in the soil when being applied to the saline-alkaline soil. By utilizing the halomonas SX-J3 provided by the invention, large-scale popularization of centralized large-scale photovoltaic area salinization improvement can be realized, the ecological restoration capability of photovoltaic plant area soil is improved, and environmental protection and sustainable utilization of land are promoted.

Description

Technical Field

[0001] The invention belongs to the technical field of microorganisms, and specifically relates to a strain of Halomonas SX-J3 and application thereof in a saline-alkali soil environment. Background Art

[0002] Saline-alkali soils often lead to soil structure deterioration, nutrient imbalance and crop growth disorders due to high salt concentration and alkalinity, which seriously affect the yield and quality of crops. The improvement of saline-alkali soils is one of the major challenges facing global agriculture and ecological restoration. Existing saline-alkali soil improvement technologies are mostly focused on the research of traditional agricultural land, including the use of chemical amendments, physical improvement methods, etc.

[0003] The concentrated photovoltaic field in high-altitude and low-latitude soda saline-alkali land is a key clean energy base developed in my country, known for its large-scale photovoltaic power stations and significant energy production capacity. However, the saline-alkali land covered in the area faces unique environmental challenges. Not only does it have the high salinity and alkalinity problems of traditional saline-alkali soils, but it is also affected by the shading effect of photovoltaic panels, soil temperature changes and mechanical compaction. These factors make the salinization problem of soil in photovoltaic fields more complicated, resulting in the adaptability and effectiveness of existing saline-alkali soil improvement technologies in photovoltaic areas not being fully evaluated, and there may be problems such as limited improvement effects, poor adaptability and high costs. Therefore, it is urgent to provide new biotechnological means to improve the ecological restoration capacity of soil in photovoltaic areas and provide new biotechnological means for the large-scale promotion of salinization improvement in centralized large-scale photovoltaic areas. Summary of the invention

[0004] The purpose of the present invention is to provide a strain of Halomonas SX-J3 and its application in a saline-alkali soil environment. The provided Halomonas has significant salt-alkali resistance, promotes seed germination in a saline-alkali environment and promotes plant growth in a saline-alkali environment, and provides technical support for the salinization improvement of centralized large-scale photovoltaic areas.

[0005] The present invention provides a strain of Halomonas ( Halomonas sp. )SX-J3, the accession number is CGMCCNO.31722.

[0006] The present invention also provides a bacterial agent, the active ingredients of which include the Halomonas SX-J3 described in the above technical solution.

[0007] Preferably, the concentration of Halomonas SX-J3 in the bacterial agent is 1×10 6 ~1×10 8 CFU / mL.

[0008] The present invention also provides the use of the Halomonas SX-J3 or the bacterial agent described in the above technical solution in one or more of the following: (1) Improvement of saline-alkali soil; (2) Promote seed germination in saline-alkali environments; (3) Promote the growth of plants in saline-alkali environments.

[0009] Preferably, the saline-alkali soil improvement includes one or more of lowering the pH of the saline-alkali soil, lowering the electrical conductivity of the saline-alkali soil, and lowering the water-soluble sodium ion content of the saline-alkali soil.

[0010] Preferably, the basic physical and chemical properties of the saline-alkali soil are: bulk density of 1.35-1.55 g / cm 3 The average water content is 33.2%, the pH value is 9.86~10.51, and the cationic components of soluble salts include Na + , Fe 2+ , Ca 2+ Mg 2+ , K + , Mn 2+ 、Zn 2+ and Cu 2+ , total salt content is 8108.43μg / g.

[0011] Preferably, the promoting the growth of plants in saline-alkali environments comprises increasing one or more of the plant height, chlorophyll content and biomass of plants in saline-alkali environments; The seeds include soybean seeds; The plants include soybeans.

[0012] Preferably, the basic physical and chemical properties of the saline-alkali environment are: bulk density is 1.35-1.55 g / cm 3 The average water content is 33.2%, the pH value is 9.86~10.51, and the cationic components of soluble salts include Na + , Fe 2+ , Ca 2+ Mg 2+ , K + , Mn 2+ 、Zn 2+ and Cu 2+ , total salt content is 8108.43μg / g.

[0013] The present invention also provides a method for improving saline-alkali soil and / or promoting the growth of plants in a saline-alkali environment, comprising: watering the soil with the bacterial agent described in the above technical solution.

[0014] The present invention also provides a method for promoting seed germination in a saline-alkali environment, comprising: soaking the seeds in the bacterial agent described in the above technical solution and then culturing them in a saline-alkali environment.

[0015] Beneficial effects: The present invention provides a strain of Halomonas SX-J3, with a deposit number of CGMCC NO.31722. The Halomonas SX-J3 provided by the present invention has strong salt-alkali resistance, can promote the germination rate of seeds (such as soybean seeds) in saline-alkali environments, promote the growth of plants in saline-alkali environments, and can be applied to saline-alkali soil to effectively reduce the alkalinity of saline-alkali soil and degrade the concentration of water-soluble sodium ions in the soil. The use of the Halomonas SX-J3 provided by the present invention can achieve large-scale promotion of salinization improvement in centralized large-scale photovoltaic areas, enhance the ecological restoration capacity of the soil in photovoltaic plant areas, and promote environmental protection and sustainable land use.

[0016] Biological deposit information Halomonas SX-J3, taxonomically named Halomonas Halobacillus sp. , deposited on August 23, 2024 at the General Microbiology Center of China Culture Collection Administration, address: No. 3, Yard 1, Beichen West Road, Chaoyang District, Beijing, postal code: 100101, and the deposit number is CGMCC NO.31722. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required to be used in the embodiments are briefly introduced below.

[0018] Figure 1 This is the colony morphology of SX-J3; Figure 2 is the phylogenetic tree of Halomonas SX-J3; Figure 3 OD of Halomonas SX-J3 under different NaCl concentrations (a) and different pH environments (b) 600 value; Figure 4 The germination of soybean seeds under different experimental treatments; a is the seed germination rate under different culture time; b is the total germination rate, * indicates p <0.05,** indicates p <0.01, *** indicates p <0.001; Figure 5 Results of soil pH (a) and conductivity (b) in different experimental treatments; ** indicates p <0.01, *** indicates p <0.001; Figure 6 The results of soil water-soluble sodium ion determination in different test treatments; ** indicates p <0.01; Figure 7This is a top view of the growth of soybean plants under different experimental treatment conditions; the left side is the control group and the right side is the experimental group; Figure 8 This is a calibration shot of the growth of soybean plants in the control group of Example 5; Fig. 9 This is a calibration shot of the growth of soybean plants in the experimental group of Example 5; Fig.10 Effects of Halomonas SX-J3 on soybean plant height (a), chlorophyll content (b) and biomass (c) in saline-alkali environment; *** indicates p <0.001. DETAILED DESCRIPTION

[0019] The present invention provides a strain of Halomonas ( Halomonas sp. )SX-J3, the accession number is CGMCCNO.31722.

[0020] The Halomonas SX-J3 of the present invention is a strain isolated from the soil between fixed plates in a large-scale photovoltaic field in a high-altitude and low-latitude soda saline-alkali land. The colony produced on the solid culture medium has a smooth, moist, shiny surface, and is milky white. The colony has neat edges and is round or approximately round in shape. The colony is slightly convex, has a uniform texture, is opaque, and is easy to pick ( Figure 1 ). The nucleotide sequence of 16S rRNA of Halomonas SX-J3 of the present invention is shown in SEQ ID NO:1.

[0021] The present invention also provides a bacterial agent, wherein the active ingredient of the bacterial agent includes the Halomonas SX-J3 described in the above technical solution. As an embodiment, the concentration of Halomonas SX-J3 in the bacterial agent of the present invention is 1×10 6 ~1×10 8 CFU / mL; As another embodiment, the concentration of Halomonas SX-J3 in the bacterial agent of the present invention is 5×10 6 ~5×10 7 CFU / mL; As another embodiment, the concentration of Halomonas SX-J3 in the bacterial agent of the present invention is 1×10 7 CFU / mL.

[0022] The present invention also provides the use of the Halomonas SX-J3 or the bacterial agent described in the above technical solution in one or more of the following: (1) improving saline-alkali soil; (2) promoting seed germination in a saline-alkali environment; (3) promoting plant growth in a saline-alkali environment.

[0023] As one embodiment, the saline-alkali soil improvement described in the present invention includes reducing the pH of saline-alkali soil, reducing the electrical conductivity of saline-alkali soil and reducing the water-soluble sodium ion content of saline-alkali soil. As another embodiment, the saline-alkali soil improvement described in the present invention includes reducing the pH of saline-alkali soil, reducing the electrical conductivity of saline-alkali soil and reducing the water-soluble sodium ion content of saline-alkali soil.

[0024] As an embodiment, the saline-alkali soil of the present invention includes saline-alkali soil in a centralized large-scale photovoltaic area. As an embodiment, the basic physical and chemical properties of the saline-alkali soil of the present invention are: bulk density of 1.35-1.55 g / cm 3 The average water content is 33.2%, the pH value is 9.86~10.51, and the cationic components of soluble salts include Na + , Fe 2+ , Ca 2+ Mg 2+ , K + , Mn 2+ 、Zn 2 + and Cu 2+ , total salt content is 8108.43μg / g.

[0025] As one embodiment, the present invention promotes the growth of plants in saline-alkali environments, including increasing one or more of the plant height, chlorophyll content, and biomass of plants in saline-alkali environments; as another embodiment, the present invention promotes the growth of plants in saline-alkali environments, including increasing the plant height, chlorophyll content, and biomass of plants in saline-alkali environments.

[0026] As an implementation method, the basic physical and chemical properties of the saline-alkali environment are: bulk density is 1.35-1.55 g / cm 3 The average water content is 33.2%, the pH value is 9.86~10.51, and the cationic components of soluble salts include Na + , Fe 2+ , Ca 2+ Mg 2+ , K + , Mn 2+ 、Zn 2+ and Cu 2+ , total salt content is 8108.43μg / g.

[0027] As an embodiment, the seeds of the present invention include soybean seeds. As an embodiment, the plants of the present invention include soybeans. The present invention is described in the specific embodiments using soybeans as an example, but it cannot be understood as the entire protection scope of the present invention.

[0028] The present invention also provides a method for improving saline-alkali soil and / or promoting the growth of plants in a saline-alkali environment, comprising: watering the soil with the bacterial agent described in the above technical solution.

[0029] As an embodiment, the watering is performed once every 5 to 10 days, and 100 to 150 mL / 500 g of soil is watered each time; as another embodiment, the watering is performed once every 7 days, and 100 mL / 500 g of soil is watered each time. As an embodiment, the number of waterings is 3 to 6 times; as another embodiment, the number of waterings is 4 times. The present invention utilizes the above-mentioned technical solution to irrigate the saline-alkali to be improved with the bacterial agent, which can significantly reduce the pH value and conductivity of the saline-alkali to be improved, reduce the salt concentration, and significantly reduce the water-soluble sodium ion content of the soil in the saline-alkali soil; it can also promote the growth of plants in saline-alkali soil environments.

[0030] The present invention also provides a method for promoting seed germination in a saline-alkali environment, comprising: soaking the seeds in the bacterial agent described in the above technical solution and then culturing them in a saline-alkali environment.

[0031] As an embodiment, the soaking time of the present invention is 2 to 5 hours; as another embodiment, the soaking time is 3 hours. As an embodiment, the light-dark ratio of the culture of the present invention is (11 to 13) / (13 to 11) hours; as another embodiment, the light-dark ratio of the culture of the present invention is 12 / 12 hours. As an embodiment, the illumination intensity of the illumination culture of the present invention is 12000 to 20000 LUX; as another embodiment, the illumination intensity of the illumination culture is 15000 LUX. As an embodiment, the relative humidity of the culture of the present invention is 69 to 90%; as another embodiment, the relative humidity of the culture is 80%. As an embodiment, the culture time of the present invention is 6 to 10 days; as another embodiment, the culture time of the present invention is 7 days. The present invention can promote the germination rate of seeds in a saline-alkali environment by soaking seeds with the bacterial agent described in the above technical solution and then culturing.

[0032] In order to further illustrate the present invention, a strain of Halomonas SX-J3 provided by the present invention and its application in a saline-alkali soil environment 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.

[0033] Example 1 Isolation and identification of strains 1. Collect soil from the surface layer of 0-20 cm between fixed panels in large-scale photovoltaic fields in high-altitude and low-latitude soda saline-alkali land. Take 5.0 g of the collected soil, add it to 45 mL of sterilized water, and place it on a shaker for shaking (180 rpm, 30 min) to make a soil suspension. Then dilute the soil suspension in a 10-fold gradient to 10 -4 times, take 0.2 mL of the soil dilution and spread it on LB solid medium (yeast powder 5 g / L, peptone 10 g / L, NaCl 100 g / L and agar powder 20 g / L, pH 9) with a salinity of 20% and a pH of 9, and culture it in an inverted manner at 30°C for 4 to 5 days.

[0034] 2. Pick the colonies with good morphology, growth potential and fast growth rate in LB solid medium, purify them on new LB solid medium by inoculation loop streak method for multiple times until pure culture, and screen out a target strain, numbered SX-J3, with round or nearly round colony morphology, light yellow, smooth surface, relatively moist, shiny, neat edges, uniform texture, opaque, slightly convex, easy to pick ( Figure 1 ).

[0035]

[0036] 4. Using the NCBI database, BLAST analysis was performed based on the 16S rRNA gene sequence of strain SX-J3, and a phylogenetic tree was constructed. The results showed that strain SX-J3 was Halobacillus andaensis NEAU-ST10-40 The 16S rRNA gene sequence of Halobacillus campisalis ASL-17 (Accession No. NR_044247.1) and Halobacillus alkaliphilus FP5 The 16S rRNA gene sequence homology of the two strains is 98.73% (accession number NR_042545.1). Halobacillus halophilus 3 (Accession No. NR_075035.2) and Halobacillus yeomjeoni MSS-402 The 16S rRNA gene sequence of the genus NR_043251.1 is 98.44% identical to Halobacillus salinus HSL-3 The homology of the 16S rRNA gene sequence of strain SX-J3 and strain SX-J3 was 98.30% (accession number NR_025244.1). Halobacillus andaensis The closest phylogenetic relationship ( Figure 2 ), combined with its bacterial morphology and colony characteristics, the strain was identified as Halomonas ( Halomonas sp. ), named Halomonas ( Halomonas sp. )SX-J3 and made a biological deposit.

[0037] Example 2 Study on the Salt-Alkali Tolerance of Halomonas SX-J3 1. Pick the Halomonas SX-J3 isolated in Example 1, inoculate it into 10 mL of fermentation medium (Tryptone 10 g / L, yeast extract 5 g / L, sodium chloride (NaCl) 10 g / L), and culture it at 35 ° C and 180 rpm for 48 h to obtain SX-J3 seed liquid.

[0038] 2. Effect of NaCl concentration on Halomonas SX-J3 The SX-J3 seed solution was inoculated into 10 mL of LB liquid medium (5 g / L yeast powder, 10 g / L peptone and corresponding concentration of NaCl, pH 7.0) with different NaCl concentrations (0wt.%, 2wt.%, 4wt.%, 6wt.%, 8wt.%, 10wt.%, 12wt.%, 14wt.%, 16wt.% and 18wt.%) at a volume ratio of 2%, and cultured at 35°C, 170 rpm for 4 d. The bacterial solution at the end of the culture was taken and the OD was measured using a spectrophotometer. 600The values ​​were determined, and preliminary analysis was performed using Microsoft Excel Office 2016 software. R language (R v4.1.2) was used for drawing. The results are shown in Figure 3 As shown in a.

[0039] according to Figure 3 As can be seen in Figure a, when 10wt.% or less NaCl is added to the LB liquid medium, the activity of Halomonas SX-J3 is good, and when the NaCl concentration is further increased, although its activity decreases, it still has a certain activity. Halomonas SX-J3 has strong salt tolerance.

[0040] 3. Effect of pH on Halomonas SX-J3 The SX-J3 seed solution was inoculated into 10 mL of LB liquid medium (5 g / L yeast powder, 10 g / L peptone, and 100 g / L NaCl) at different pH values ​​(2.8, 3.4, 4.2, 5.0, 5.8, 6.6, 7.4, 8.2, 9.0, and 10.0) at a volume ratio of 2%, and cultured at 35°C, 170 rpm for 4 d. The bacterial solution at the end of the culture was taken and the OD was measured using a spectrophotometer. 600 The values ​​were determined, and preliminary analysis was performed using Microsoft Excel Office 2016 software. R language (R v4.1.2) was used for drawing. The results are shown in Figure 3 As shown in b.

[0041] according to Figure 3 As can be seen in b, the activity of Halomonas SX-J3 was good when the pH of LB liquid medium was ≥5.0, and the activity was the best when the pH was 7.0 (initial LB medium). 600 =1.136, when 7.4≤pH≤10.0, the activity will decrease slightly with the increase of alkalinity, but still maintain a high activity intensity. When pH<5.0, its activity is poor. Halomonas SX-J3 has strong alkali resistance and is not suitable for growth in acidic environment.

[0042] Example 3 Study on promoting soybean seed germination in alkaline environment by Halomonas SX-J3 1. Preparation of Halomonas SX-J3 bacterial suspension The Halomonas SX-J3 isolated in Example 1 was selected and inoculated into 10 mL of LB liquid medium (tryptone 10 g / L, yeast extract 5 g / L and sodium chloride 10 g / L, pH 7.0), and cultured at 35 ° C, 180 rpm for 48 h to obtain SX-J3 seed solution; the concentration of SX-J3 seed solution was adjusted to 1.0×10 8CFU / mL, and obtain the suspension of Halomonas SX-J3.

[0043] 2. Select soybean seeds of uniform size and fullness, sterilize them with 75% v / v ethanol for 3 min, then wash them with sterile water 3 times to remove the residual ethanol. The treated seeds are randomly divided into 4 treatment groups, with 3 replicates in each group, and the following treatments are performed: Control group (CK): The treated soybean seeds were soaked in sterile water at room temperature for 3 h; Bacteria solution experimental group (J3): The treated soybean seeds were immersed in the suspension of Halomonas SX-J3 at room temperature for 3 h; Salt-alkali stress solution experimental group (YJ): the treated soybean seeds were immersed in 10 wt.% NaCl solution with a pH of 10 at room temperature for 3 h; Experimental group of mixed bacterial suspension and saline-alkali stress solution (J3+YJ): 10wt.% NaCl solution with a pH value of 10 and Halomonas SX-J3 bacterial suspension were mixed in equal volumes to obtain a mixed solution; the treated soybean seeds were soaked in the mixed solution at room temperature for 3 h.

[0044] After the soaking, a sterile culture dish was selected for the experiment. Specifically: pre-sterilized filter paper was spread on a 150 mm plate, and filter paper with good water absorption and water retention was used as the paper bed. In the plant incubator, the daytime temperature was set at 30°C, the light was 15,000 LUX for 12 hours, and the relative humidity was 80%; the dark temperature was 12 hours, the temperature was set at 25°C, and the relative humidity was 75%, and the culture was continued for 7 days. The germination rate of the seeds was counted from the second day, and the germination of the seeds on the 7th day was the total germination rate. In the SPSS software, a statistical test was performed according to the one-way analysis of variance (ANOVA) to determine whether there was a significant difference in the soybean germination rate between different experimental groups. After the data was analyzed, the R language (R v4.1.2) was used to draw the graph. The results are shown as follows. Figure 4 shown.

[0045] according to Figure 4 It can be seen that within 7 days, the soybean seed germination rate of the control (CK) group was the highest, with an average germination rate of 93.67%; the soybean seed germination rate under the treatment of SX-J3 bacterial suspension was 90.67%; and the soybean seed germination rate under the saline-alkali stress solution was the lowest, with an average germination rate of 19.67%; when the SX-J3 bacterial suspension and the saline-alkali stress solution were mixed (J3+YJ), the soybean seed germination rate increased by 82.23%. This shows that the addition of SX-J3 bacterial suspension has a good effect on reducing the stress of soybean seeds under saline-alkali solution. When only SX-J3 bacterial suspension is added, the soybean seed germination rate is still very high (90.67%), indicating that the bacterial solution will not inhibit the germination rate of soybean seeds ( Figure 4 The results of the total germination rate difference analysis showed that the soybean germination rates in the CK, J3 and J3+YJ treatments were all higher than those in the YJ group treatment, and there was no significant difference in the soybean germination rates in the CK and SX-J3 bacterial suspension treatments ( Figure 4 (b)

[0046] Example 4 Study on Alkalinity Reduction and Salt Dissolution of Halomonas SX-J3 1. Pick the Halomonas SX-J3 isolated in Example 1 and inoculate it into 10 mL LB liquid fermentation medium (tryptone 10 g / L, yeast extract 5 g / L and sodium chloride 10 g / L, pH 7.0), and culture at 35 ° C, 180 rpm for 48 h to obtain SX-J3 seed solution; adjust the concentration of SX-J3 seed solution to 1.0×10 7 CFU / mL, and obtain the suspension of Halomonas SX-J3.

[0047] 2. Soil matrix collection and processing: On July 19, 2024, natural salinized soil was collected from a centralized photovoltaic field in a high-altitude and low-latitude soda saline-alkali land. The soil sampling depth was 0-20 cm. The collected soil was naturally air-dried for about a week and sieved to remove non-soil impurities. The soil bulk density between the plates was determined to be between 1.35 and 1.55 g / cm 3 The average soil moisture content is 33.2%, the soil pH is between 9.86 and 10.51, and the main cation component of soluble salt is Na + , Fe 2+ , Ca 2+ Mg 2+ , K + , Mn 2+ 、Zn 2+ and Cu 2+ , total salt content is 8108.43μg / g.

[0048] 3. Mix the sieved soils evenly, put them into 0.4L flower pots, and randomly divide them into an experimental group (J3) and a control group (CK), with 4 replicates in each group. The following treatments were performed: Control group (CK): NaCl solution (10 g / L) was used to irrigate 100 mL into the soil matrix every 10 days; Experimental group (J3): Use the Halomonas SX-J3 bacterial suspension obtained in step 1 and irrigate 100 mL into the soil matrix every 10 days.

[0049] The soil was placed in a plant incubator, set at 30°C during the day, 15,000 LUX for 12 h, and 80% relative humidity; dark temperature for 12 h, temperature set at 25°C, relative humidity of 75%, and cultured continuously for 40 days, i.e., 4 waterings in total.

[0050] 4. After the experiment in step 3, air-dry the soil and pass it through a 2 mm sieve. Take out 10 g of the treated soil and put it in a centrifuge tube. Add 25 mL of RO water and stir the mixture for 30 minutes with a magnetic stirrer or a manual stirrer. Use a pH meter and a conductivity meter to measure the soil pH and conductivity, respectively. Perform a statistical test using the independent sample t-test in SPSS software to determine whether there are significant differences in soil pH and conductivity between different experimental treatment groups. After analyzing the data, use R language (R v4.1.2) to draw the graph. The results are shown in the figure. Figure 5 shown.

[0051] according to Figure 5 It can be seen that the soil pH value after 40 days of irrigating with the suspension of Halomonas SX-J3 was 9.85, and the soil pH value after irrigating with 10 g / L NaCl solution was 10.04. The soil pH of the experimental group was significantly lower than that of the control group ( p <0.01, indicating that Halomonas SX-J3 can reduce the pH value of strongly alkaline soil ( Figure 5 In addition, the soil conductivity value of the control treatment after irrigating with 10g / L NaCl solution was 3.62Ms / cm, and the soil conductivity value after treatment with Halomonas SX-J3 suspension was 2.36Ms / cm, which was significantly lower than the soil conductivity of the control treatment ( p <0.001, indicating that Halomonas SX-J3 can reduce the salt concentration ( Figure 5 (b)

[0052] 5. After the experiment in step 3, air-dry the soil naturally, sieve through a 100-mesh sieve, take 10 g of soil and add 50 ml of Watsons distilled water, use an oscillator at 35°C and 180 rpm, shake and culture for 1 hour to ensure that the water-soluble sodium salt is fully dissolved. The soil sodium salt concentration in the experimental group and the control group was determined using IPC-OES. A statistical test was performed using the independent sample t-test (t-test) in SPSS software to determine whether there was a significant difference in soil sodium salt concentration between different experimental treatment groups. After analyzing the data, R language (R v4.1.2) was used to draw the graph. The results are shown in the figure. Figure 6 shown.

[0053] according to Figure 6It can be seen that the water-soluble sodium ion concentration of the soil under the control group treatment was 3944.37 μg / g, and the water-soluble sodium ion concentration of the soil under the treatment of Halomonas SX-J3 was 3476.78 μg / g, which was significantly lower than that of the control group ( p <0.01). This indicates that the use of Halomonas SX-J3 to cultivate soil can significantly reduce the content of water-soluble sodium ions in saline-alkali soil.

[0054] Example 5 Study on the effect of Halomonas SX-J3 on promoting the growth of soybean seeds in alkaline environment 1. Preparation of Halomonas SX-J3 bacterial suspension The Halomonas SX-J3 isolated in Example 1 was selected and inoculated into 10 mL of LB liquid medium (tryptone 10 g / L, yeast extract 5 g / L and sodium chloride 10 g / L, pH 7.0), and cultured at 35°C and 180 rpm for 48 h to obtain SX-J3 seed solution; the concentration of the SX-J3 seed solution was adjusted to 1.0×10 7 CFU / mL, and obtain the suspension of Halomonas SX-J3.

[0055] 2. Planting soil matrix: On July 19, 2024, natural salinized soil was collected from a centralized photovoltaic field in a high-altitude, low-latitude soda saline-alkali land, with a soil sampling depth of 0-20 cm. The collected soil was naturally air-dried for about a week, sieved to remove non-soil impurities, and other pre-treatments to obtain sieved soil for use; the pH of the sieved soil was measured to be 10.06, and the total salt content was 7.98 mg / g; Nutrition soil (purchased from Stanley), vermiculite and perlite were mixed in a volume ratio of 2:1:1, stirred evenly, and obtained nutrition soil.

[0056] 3. Select healthy soybean seeds for surface disinfection (such as treating with 70% v / v ethanol for 1 min, then treating with 1% sodium hypochlorite for 5 min, and finally rinsing with sterile water several times) to obtain treated soybean seeds.

[0057] 4. Fill 4 / 5 of a 0.5L flower pot with a mass ratio of 3:1 between the sieved soil and the nutrient matrix. First, fill the sieved soil into a 0.4L flower pot, sow the treated soybean seeds on top of the sieved soil, and then cover with nutrient soil. Plant 4 soybean seeds in each flower pot and place it in a plant incubator. Set the daytime temperature to 30°C, light 15000LUX 12h, relative humidity 80%; dark temperature 12 h, temperature setting 25°C, relative humidity 80%; during the incubation period, perform the following treatments: Control group (CK): NaCl solution (10 g / L) was used to irrigate 100 mL into the soil matrix every 10 days; Experimental group (J3): Use the Halomonas SX-J3 bacterial suspension obtained in step 1 and irrigate 100 mL into the soil matrix every 10 days.

[0058] The control group and the experimental group were set up with 4 replicates, and four irrigation treatments were performed on the 1st, 11th, 21st and 31st days after planting. The height and chlorophyll content of soybean plants were measured on the 35th day of cultivation. The experiment was ended on the 40th day, and the total biomass of soybean plants under different treatments was weighed. The data were statistically tested according to the independent sample t-test (t-test) in SPSS software to determine whether there were significant differences in soybean plant height, chlorophyll content and biomass between different experimental treatment groups. After data analysis, R language (R v4.1.2) was used for drawing. The results are shown in Figure 2. Figures 7-10 shown.

[0059] according to Figures 7-10 It can be seen that compared with the control group, the soybean plants in the experimental group irrigated with the suspension of Halomonas SX-J3 grew better ( Figures 7-9 ), the average height of soybean plants in the control group and the experimental group were 22.40g and 33.50g respectively ( Fig.10 a); the average biomass were 0.94g and 1.78g ( Fig.10 b), the relative chlorophyll contents were 27.01g and 35.83g ( Fig.10 c). The height, biomass and relative content of chlorophyll of soybean plants in the experimental group irrigated with the suspension of Halomonas SX-J3 were significantly higher than those in the control group. The Halomonas SX-J3 provided by the present invention helps soybean plants grow in saline-alkali soil and can improve the growth physiological indicators of soybean plants in saline-alkali environment.

[0060] According to the above content, it can be seen that the Halomonas SX-J3 provided by the present invention can promote the germination rate of seeds in a saline-alkali environment, promote the growth of plants in a saline-alkali environment, and can be applied to saline-alkali soil to effectively reduce the alkalinity of the saline-alkali soil and degrade the concentration of water-soluble sodium ions in the soil.

[0061] 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 Halomonas ( Halomonas sp. )SX-J3, the deposit number is CGMCC NO.31722.

2. A bacterial agent, characterized in that The active ingredient of the bacterial agent includes the Halomonas SX-J3 described in claim 1.

3. The bacterial agent according to claim 2, characterized in that The concentration of Halomonas SX-J3 in the bacterial agent is 1×10 6 ~1×10 8 CFU / mL.

4. Use of the Halomonas SX-J3 of claim 1 or the bacterial agent of claim 2 or 3 in one or more of the following: (1) Improvement of saline-alkali soil; (2) Promote seed germination in saline-alkali environments; (3) Promote the growth of plants in saline-alkali environments.

5. The use according to claim 4, characterized in that: The saline-alkali soil improvement includes one or more of lowering the pH value of the saline-alkali soil, lowering the electrical conductivity of the saline-alkali soil, and lowering the water-soluble sodium ion content of the saline-alkali soil.

6. The use according to claim 4 or 5, characterized in that: The basic physical and chemical properties of the saline-alkali soil are: bulk density is 1.35~1.55g / cm 3 The average water content is 33.2%, the pH value is 9.86~10.51, and the cationic components of soluble salts include Na + , Fe 2+ , Ca 2+ Mg 2+ , K + , Mn 2+ 、Zn 2+ and Cu 2+ , total salt content is 8108.43μg / g.

7. The use according to claim 4, characterized in that: The promoting the growth of plants in saline-alkali environments comprises increasing one or more of the plant height, chlorophyll content and biomass of plants in saline-alkali environments; The seeds include soybean seeds; The plants include soybeans.

8. The use according to claim 4 or 7, characterized in that: The basic physical and chemical properties of the saline-alkali environment are: bulk density is 1.35~1.55g / cm 3 The average water content is 33.2%, the pH value is 9.86~10.51, and the cationic components of soluble salts include Na + , Fe 2+ , Ca 2+ Mg 2+ , K + , Mn 2+ 、Zn 2+ and Cu 2+ , total salt content is 8108.43μg / g.

9. A method for improving saline-alkali soil and / or promoting plant growth in a saline-alkali environment, characterized in that: include: Use the bacterial agent described in claim 2 or 3 to irrigate the soil.

10. A method for promoting seed germination in a saline-alkali environment, characterized in that: include: The seeds are soaked in the bacterial agent described in claim 2 or 3 and then cultured in a saline-alkali environment.

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