Sporosarcina strain RH34 and application thereof

Abstract

The invention discloses a sporosarcina sp. Strain RH34 and an application of the sporosarcina sp. Strain RH34 and the application of the sporosarcina sp. Strain RH34. The sporosarcina strain RH34 is preserved in the China General Microbiological Culture Collection Center (CGMCC), the preservation address is No.3, yard 1, Beichen West Road, Chaoyang District, Beijing, the preservation date is December 25, 2024, and the preservation number is CGMCC NO.33199. The sporosarcina strain RH34 can be used for preparing the sporosarcina strain RH34. The alfalfa rhizosphere microorganism sporosarcina strain RH34 is separated from alfalfa roots in salinized soil, and has the functions of dissolving organic phosphorus, dissolving inorganic phosphorus, producing biological membranes, producing siderophores, producing IAA and producing ACC deaminase. Seed soaking and germination under salt stress can obviously improve the germination index of alfalfa seeds. The growth condition of alfalfa seedlings can be improved under salt stress.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of microorganisms, and particularly relates to a strain of Sporosarcina sp. Sporosarcina sp. ) and application thereof. BACKGROUND

[0002] Soil salinization is a core environmental constraint factor of global agricultural production. According to statistics, more than 20% of irrigated farmland in the world is threatened by salt damage, which seriously weakens land productivity and endangers ecological safety. In China, saline soil is widely distributed, with a total area of about 100 million hectares, accounting for about 10% of the land area, which poses a significant pressure on food security and sustainable agricultural development. Under this background, the biological remediation and resource utilization of saline-alkali soil have become a key way to improve land utilization and enhance the resilience of agricultural systems.

[0003] In the practice of planting high-quality forage grasses such as alfalfa in saline soil areas, the core strategy to enhance the salt tolerance of crops focuses on two major directions: breeding of salt-tolerant varieties and soil microbial regulation. Traditional research focuses on tapping the genetic potential of plant salt tolerance, and through breeding techniques, excellent varieties that adapt to high-salt habitats are cultivated. In recent years, the in-depth analysis of microbial-plant interaction mechanisms has provided an innovative approach to saline-alkali soil improvement. Specific rhizosphere functional microorganisms can significantly improve the physiological adaptability and growth performance of plants under salt stress through key pathways such as regulating plant hormone balance, strengthening ion homeostasis maintenance ability, and inducing systemic resistance, showing a broad field application prospect.

[0004] Using functional microorganisms as "biological enhancers" of plant salt tolerance not only forms a synergistic effect with the host's inherent salt tolerance mechanism, but also expands the crop's adaptation boundary under higher salt gradients, providing an environmentally friendly and significantly potential technical solution for the efficient development and utilization of saline-alkali soil resources. Therefore, there is an urgent need in the prior art for a new strain that can improve the salt tolerance of alfalfa. SUMMARY

[0005] The purpose of the present application is to overcome the deficiencies in the prior art and provide a Sporosarcina sp.

[0006] The purpose of the present application is achieved by the following technical solution: a Sporosarcina sp. Sporosarcina sp. The Sporosarcina sp. strain RH34 is preserved at the China General Microbiological Culture Collection Center, located at No. 1, Beichen West Road, Haidian District, Beijing, with a preservation date of December 25, 2024, and a preservation number of CGMCC NO. 33199.

[0007] The application further provides application of the S. pastorianus strain RH34 in improving seed germination indexes of alfalfa under salt stress.

[0008] Further, the salt stress is 200mmol / L NaCl stress, and the germination indexes include germination energy, germination rate, germination index, radicle length, plumule length and fresh weight of group seedlings.

[0009] Further, the salt stress is 250mmol / L NaCl stress, and the germination indexes include germination rate, radicle length, plumule length and fresh weight of group seedlings.

[0010] The application further provides application of the S. pastorianus strain RH34 in improving seed germination indexes of alfalfa under salt stress.

[0011] Further, the salt stress is 200mmol / L NaCl stress, and the germination indexes include germination energy, germination rate, germination index, radicle length, plumule length and fresh weight of group seedlings.

[0012] The application has the following beneficial effects: the S. pastorianus strain RH34 is separated from alfalfa rhizosphere microorganisms planted in saline soil of a test base of Inner Mongolia Agricultural University, has the functions of dissolving organic phosphorus, dissolving inorganic phosphorus, producing a biological membrane, producing an iron carrier, producing IAA and producing ACC deaminase, and can obviously improve seed germination indexes of alfalfa under 200mmol / L and 250mmol / L NaCl stress, and can improve growth conditions of alfalfa seedlings under 200mmol / L NaCl stress. BRIEF DESCRIPTION OF DRAWINGS

[0013] Figure 1 is a colony morphology of the strain RH34; Figure 2 is a culture result of the strain RH34 in inorganic phosphorus-containing solid culture medium and organic phosphorus-containing solid culture medium; wherein A is a culture result of the strain RH34 in the inorganic phosphorus-containing solid culture medium, and B is a culture result of the strain RH34 in the organic phosphorus-containing solid culture medium; Figure 3 is a culture result of the strain RH34 in potassium-containing solid culture medium; Figure 4 is 96-hole plate crystal violet dye staining of the strain RH34; Figure 5 is a culture result of the strain RH34 in iron carrier selective solid culture medium; Figure 6 is 96-hole plate Salkowski reagent staining of the strain RH34; wherein CK is a control group, and RH34 is a test group; Figure 7This is a bar chart of various germination indicators of alfalfa seeds under 200 mmol / L NaCl stress; where A is the germination potential bar chart, B is the germination rate bar chart, C is the germination index bar chart, D is the radicle length bar chart, E is the plumule length bar chart, and F is the fresh weight of the seedling population bar chart. Figure 8 This is a bar chart of various germination indicators of alfalfa seeds under 250 mmol / L NaCl stress; where A is the germination potential bar chart, B is the germination rate bar chart, C is the germination index bar chart, D is the radicle length bar chart, E is the plumule length bar chart, and F is the fresh weight of the seedling population bar chart. Figure 9 It is 200 mmol / L Bar charts showing the growth indicators of alfalfa seedlings under NaCl stress; where A is the plant height bar chart; B is the stem diameter bar chart; C is the leaf area bar chart; D is the aboveground fresh weight bar chart; and E is the aboveground dry weight bar chart. Figure 10 These are bar charts showing the aboveground biomass of other plant seedlings under salt stress; where A is the aboveground biomass bar chart of tomato seedlings; and B is the aboveground biomass bar chart of barley seedlings. Detailed Implementation

[0014] The present invention will now be described in detail with reference to the accompanying drawings.

[0015] Unless otherwise specified, the chemical reagents used in the following examples are all commercially available conventional reagents, and the technical means used in the examples are conventional means well known to those skilled in the art.

[0016] The TSA solid culture medium used in the examples included: 15 g / L tryptone, 5 g / L soybean peptone, 5 g / L NaCl and 15 g / L agar.

[0017] The TSB liquid culture medium used in the examples included: 8.5 g / L tryptone, 1.5 g / L plant peptone, 2.5 g / L NaCl, 1.25 g / L K2HPO4, 1.25 g / L glucose, and distilled water.

[0018] The inorganic phosphorus-containing solid culture medium used in the examples included: KCl 0.2 g / L, glucose 10 g / L, Ca3(PO4) 5 g / L, MgCl2·6H2O 0.5 g / L, MgSO4·7H2O 0.25 g / L, (NH4)2SO4 0.1 g / L and agar 20 g / L.

[0019] The solid culture medium containing organic phosphorus used in the embodiments includes: glucose 10 g / L, (NH4)2SO40.5 g / L, NaCl 0.3 g / L, KCl 0.3 g / L, FeSO4·7H2O 0.03 g / L, SO4Mn4·H2O 0.03 g / L, lecithin 0.2 g / L, yeast extract 0.4 g / L (Beijing Coolabo Technology Co., Ltd., model: CY12011-500 g), and agar 20 g / L, pH 7.0-7.5.

[0020] The solid culture medium containing potassium used in the embodiments includes: sucrose 5 g / L, Na2HPO42 g / L, MgSO4·7H2O 0.005 g / L, FeCl30.005 g / L, CaCO30.1 g / L, potassium feldspar powder 0.1 g / L, and agar 20 g / L.

[0021] The siderophore selective solid culture medium used in the embodiments includes: CAS (chromazurol S) 60.5 mg / L, distilled water 50 ml / L, HCl 8 μL / L, 2 mol / L FeCl3·6H2O 5 μL / L, HDTMA (hexadecyl trimethyl ammonium bromide) 72.9 mg / L, proteose peptone 20 g / L, MgSO4·7H2O 1.5 g / L, KH2PO41.2 g / L, glycerol 10 g / L, agar 13 g / L, pipes (piperazine-1, 4-diethanesulfonic acid) 30 g / L, and 50% NaOH 12 ml / L.

[0022] Example 1 Isolation, screening and identification of strain RH34 (I) Isolation and screening The strain is derived from the roots of alfalfa planted in the saline soil of the Hailiutu experimental base of Inner Mongolia Agricultural University. The saline soil of the Hailiutu experimental base was taken, alfalfa seedlings were planted, and then salt stress treatment was performed (the whole pot of seedlings was soaked in 200 mmol / L NaCl solution for 30 min), and the alfalfa seedlings were continuously cultured for 4 weeks, and then the samples were collected for subsequent analysis.

[0023] Preparation of plant root samples: the alfalfa roots were taken out with sterile tweezers and put into a test tube containing 25 ml of phosphate buffer, vortexed for 15 s, and then the roots were stuck to the inner wall of the test tube with sterile tweezers, and the phosphate buffer was slowly poured out, and 25 ml of new phosphate buffer was added. This step was repeated until there was no rhizosphere soil in the phosphate buffer. The alfalfa roots were put into a 15 ml test tube, and 12 ml of phosphate buffer was added. The test tube was put into an ultrasonic sample disrupter, and ultrasonic disruption was performed for 5 min, and vortexed for 5 s. The roots were rinsed with phosphate buffer. The root system was dried on filter paper, and after quick freezing in liquid nitrogen, it was stored at -80℃.

[0024] The plant root samples were taken, cultured in TSA solid medium, and incubated at 25℃. According to the color (yellow) and morphology (irregular edge) of the colonies, the colonies were picked and cloned, and the colonies produced by the culture of the plant root samples were streaked on new TSA solid medium for purification culture. The bacteria in the TSA solid medium after purification were inoculated into TSB liquid medium, 40% (volume fraction) glycerol was added, and the mixture was stored in a -80℃ ultra-low temperature freezer for standby use.

[0025] (II) Classification and identification 1. Activation of strains: The strains stored in the -80℃ ultra-low temperature freezer were taken out, thawed at room temperature, and then activated and cultured on TSA solid medium, and the colony morphology was observed.

[0026] 2. Morphological characteristics of the strains: The cytological characteristics of the strains were as follows: the colonies were light yellow and slightly white, the surface was moist, and the edge was irregular (see Figure 1 ).

[0027] 3. 16S rRNA identification: The strains were taken out from the -80℃ ultra-low temperature freezer, inoculated into TSB liquid medium, and cultured at 25℃, 220 r / min on a shaking table for 3 days to obtain a bacterial solution. Then 1 mL of the bacterial solution was taken, centrifuged to collect the bacterial cells, and the genomic DNA in the sample was extracted using the MoBio Power Soil DNA Isolation Kit (MoBio Company, USA) according to the standard process of the kit manual. The genomic DNA was stored at -20℃ for standby use.

[0028] The 16S rRNA gene in the above-extracted genomic DNA was amplified by PCR using the following specific primer pairs: The 16S rRNA in the above-extracted genomic DNA was amplified using primers 16S-63F and 16S-1389R: Forward primer 16S-63F: AGTTTGATCMTGGCTCAG (SEQ ID NO: 2); Reverse primer 16S-1389R: GGTTACCTTGTTACGACTT (SEQ ID NO: 3).

[0029] Amplification system (total 50 μL): 10 x Buffer 2.5 μL, 2 mmol / L dNTP 2.5 μL, forward primer 16S-63F 1 μL, reverse primer 16S-1389R 1 μL, dNTP (2 mmol / L) 2.5 μL, DNA 2 μL, Taq polymerase 0.1 μL, and ddH2O 15.9 μL.

[0030] The PCR reaction program was denaturation at 94℃ for 5 min, 30 cycles of 94℃ for 1 min, 55℃ for 1 min, 72℃ for 1 min, and extension at 72℃ for 10 min. The PCR product was detected by 1.5% agarose gel electrophoresis. After the extracted DNA passed the purity and integrity detection, it was sent to a sequencing company (Beijing Novogene Bioinformatics Technology Co., Ltd.) for sequencing.

[0031] After comprehensive analysis of the cell morphology and 16S gene sequence and comparison with the NCBI (National Center for Biotechnology Information) database, the strain was identified as a Sporosarcina sp. strain, named RH34. The strain RH34 was preserved in the China General Microbiological Culture Collection Center on December 25, 2024, at the address of No. 1, Beichen West Road, Chaoyang District, Beijing, on December 25, 2024, with the preservation number of CGMCC NO. 33199.

[0032] Example 2: Biological function test of strain RH34 1. Strain pretreatment: The test strain was inoculated into 20 ml of TSB liquid medium and cultured in a 25℃, 220 r / min shaker for 3 days. Then, the bacterial cells were collected by centrifugation at 4℃, 8000 r / min for 10 min, and the bacterial liquid concentration was adjusted to OD 600 = 1 using a spectrophotometer for subsequent tests.

[0033] 2. Phosphorus solubilization capacity determination: Take 2 μL of bacterial solution and inoculate onto the surface of solid medium containing organic phosphorus and solid medium containing inorganic phosphorus, respectively, and cultivate at 25°C, with 3 biological replicates for each treatment. After 3-5 days, observe whether the culture medium has a phosphorus-dissolving ring. Whether or not the phosphorus-dissolving ring appears is used to determine whether the strain has the function of dissolving insoluble organic phosphorus and inorganic phosphorus.

[0034] The results are shown in Figure 2 A 、 Figure 2 B, and transparent phosphorus-dissolving rings appear in the culture medium, proving that the strain RH34 has the ability to dissolve organic phosphorus and inorganic phosphorus.

[0035] 3. Potassium-dissolving ability determination: Take 2 μL of bacterial solution and inoculate onto the surface of solid medium containing potassium, and cultivate at 25°C, with 3 biological replicates. After 3-5 days, observe the growth condition of the colonies on the surface of the medium, and record whether transparent oil droplet-shaped colonies appear. If transparent oil droplet-shaped colonies appear, it proves that the strain has the ability to dissolve potassium.

[0036] As shown in Figure 3 , no oil droplet-shaped colonies appear on the bacterial plate, proving that the strain RH34 has no potassium-dissolving ability.

[0037] 4. Bacterial film-producing ability determination: Take 20 μL of bacterial solution and add it to a 96-well plate pre-loaded with 180 μL of TSB liquid medium. After 2-3 days of cultivation at 25°C and 220 r / min on a shaking table, let it stand. Add 0.1 μL of crystal violet dye (containing 0.1% Crytorl) to each well and cultivate for 15 min. Wash with sterile water for 3 times. Add 96% alcohol 200 μL, and dissolve the dye remaining on the wall for 2 min. Observe whether there is purple coloring in the 96-well plate. Whether there is purple coloring and the degree of coloring are used to determine whether the strain RH34 has the ability to produce bacterial film and the strength of the ability.

[0038] As shown in Figure 4 , purple-colored bacterial film appears at the bottom of the 96-well plate, proving that the strain RH34 has the ability to produce bacterial film.

[0039] 5. Iron carrier-producing ability determination: Take 2 μL of bacterial solution and inoculate onto the surface of iron carrier selective solid medium, and cultivate at 25°C, with 3 biological replicates. After 3-5 days, observe whether there is an orange-yellow secretory ring in the iron carrier selective solid medium. If there is an orange-yellow secretory ring, it proves that the strain has the ability to produce iron carrier.

[0040] As shown in Figure 5 , the colonies in the culture medium have an orange-yellow secretory ring, proving that the strain RH34 has the ability to produce iron carrier.

[0041] 6. ACC deaminase-producing ability determination: Take 10 ml of bacterial solution in a 15 ml centrifuge tube, centrifuge at 4°C, 8000 r / min for 10 min, pour off the supernatant, leave the bacterial precipitate, add 7.5 ml of nitrogen-free DF medium (Beijing Coolab Technology Co., Ltd., Model: MM6150-2) to the centrifuge tube, and add 45 μL of filtered and sterilized 0.5 mol / L ACC (1-aminocyclopropane-1-carboxylic acid) solution, so that the concentration of ACC solution is 3 mmol / L, then cultivate at 25°C, 220 r / min for 24 h (to induce the ACC deaminase activity of the bacteria), and obtain the bacterial suspension. Centrifuge the above bacterial suspension at 4°C, 8000 r / min for 10 min, remove the supernatant, collect the bacterial precipitate, add 5 ml of Tris-HCl buffer (0.1 mol / L, pH 7.6) to resuspend the bacteria, centrifuge at 4°C, 8000 r / min for 10 min, and collect the precipitate, which is repeated for 3 times to completely remove the nitrogen-free DF medium. Add 1 ml of Tris-HCl buffer (0.1 mol / L, pH 7.6) to the bacterial precipitate to suspend the bacteria, then transfer to a 1.5 ml centrifuge tube, centrifuge at 15000 r / min for 5 min, remove the supernatant, and collect the bacterial precipitate; then add 600 μL of Tris-HCl buffer (0.1 mol / L, pH 8.5) to the bacterial precipitate, add 30 μL of toluene, vortex for 30 s to break the bacteria. Take 200 μL of the broken cell bacterial suspension, add 20 μL of ACC solution (0.5 mol / L), mix well, and then incubate in a 30°C water bath for 15 min. Then add 1 ml of HCl solution (0.56 mol / L) and mix well, centrifuge at room temperature at 15000 r / min for 5 min, and obtain the centrifugal supernatant. Take 1 ml of the above centrifugal supernatant, add 800 μL of HCl solution (0.56 mol / L), mix well, and then add 300 μL of 2,4-dinitrophenylhydrazine (2 g / L, dissolved with 2 mol / L HCl), and incubate in a 30°C water bath for 30 min. Then measure the absorbance at 540 nm with a UV-visible spectrophotometer, with distilled water as the control. According to the OD value, it is determined whether the strain RH34 can produce ACC deaminase.

[0042] The results are shown in Table 1, and the OD value of the strain RH34 is 0.020, which proves that the strain RH34 has strong ability to produce ACC deaminase.

[0043] Table 1 OD values of ACC deaminase and IAA of the strain RH34 Treatment ACC deaminase (OD 450 )]> IAA (OD 600 )]> CK 0 0 RH34 0.020 0.428 7. IAA production ability determination: In a 96-well plate, pre-add 180 μL of TSB liquid medium and 1.5 μL of tryptophan solution (0.11 g / L, sterilized by filtration). Add 20 μL of bacterial culture to the 96-well plate and incubate at 25℃ and 220 r / min for 2-3 days. Then add Sachs' reagent (3.51 mL of 35% HClO4 + 2 μL of 0.5 mol / L FeCl3) and incubate in the dark for 30 min. Observe whether the 96-well plate becomes turbid. [The last sentence appears to be incomplete and possibly refers to a measurement based on OD...] 600 The absorbance of strain RH34 was measured under certain conditions, with distilled water as the control (CK), to determine whether strain RH34 has the function of producing IAA.

[0044] The results are as follows Figure 6 As shown, the 96-well plate of strain RH34 was more turbid than the CK control, and the OD value of IAA of strain RH34 was 0.541 (see Table 1), which proves that strain RH34 has the ability to produce IAA.

[0045] Example 3: Germination of alfalfa seeds after soaking under 200 mmol / L NaCl stress Remove the bacterial strain from the refrigerator, streak it onto fresh TSA solid medium, and incubate statically at 25°C for 3-5 days. After colonies have grown, elute them using sterile 0.9% NaCl solution in a laminar flow hood, and then adjust the OD of the bacterial culture using a spectrophotometer. 600 =0.1, prepare RH34 bacterial solution for later use.

[0046] Plump and intact alfalfa seeds were selected and soaked in RH34 bacterial solution for 8 hours. Sterile water was used as a control. Germination tests were conducted on a paper bed containing 200 mmol / L NaCl solution. Fifty seeds were placed in each petri dish, with three replicates. The petri dishes were pre-sealed with two layers of sealing film to prevent moisture evaporation, and water was replenished daily to maintain a stable salt concentration. The number of germinated seeds in each dish was recorded daily until day 7. Germination potential, germination rate, and germination index were calculated. At the end of the experiment, 10 seedlings were randomly selected from each petri dish to measure the radicle length and plumule length, and the fresh weight of all seedlings in the dish was determined.

[0047] The result is Figure 7 It can be seen that after soaking in RH34, all germination indicators of alfalfa seeds were higher than those of the CK control. Among them, the germination rate, germination index, and radicle length were significantly higher than those of the CK control (see...). Figure 7 B-7D was 91.30%, 31.11%, and 36.67% higher than the CK control, respectively. P< The germination potential, plumule length, and fresh weight of the seedling population were significantly higher than those of the control group (0.05). Figure 7 A, Figure 7 E-7F was 55.84%, 16.88%, and 127.49% higher than the CK control, respectively.P< 0.01).

[0048] Example 4 250 mmol / L Alfalfa seeds germinated after soaking under NaCl stress The experimental steps in this embodiment are the same as in Example 3, except that the 200 mmol / L NaCl solution is replaced with a 250 mmol / L NaCl solution.

[0049] The result is Figure 8 It can be seen that after soaking in RH34, all germination indicators except germination potential were higher than those of the CK control. Germination rate, radicle length, and plumule length were significantly higher than those of the CK control (see...). Figure 8 B, 8D, and 8E were 89.19%, 51.57%, and 11.74% higher than the CK control, respectively. P< 0.05), the fresh weight of the seedling population was significantly higher than that of the CK control (see Figure 8 F), which was 494.87% higher than the CK control (F). P< 0.01).

[0050] Example 5 200 mmol / L Alfalfa seedling growth under NaCl stress Select plump, intact alfalfa seeds and germinate them in sterile petri dishes. After 6-7 days, select seedlings with uniform growth and transplant them into pots (pot dimensions: 0cm × 10cm × 8cm; the substrate in the pot consists of sterilized vermiculite and volcanic rock, with the weight of the volcanic rock being twice the weight of the vermiculite). Three days after transplanting, inoculate with RH34 strain (first prepare the bacterial solution using the same method as in Example 3, the difference being that OD is prepared). 600 =1 RH34 bacterial solution; after preparing the RH34 bacterial solution, use a pipette to inject 1 ml of RH34 bacterial solution into the soil around the roots of the alfalfa to complete the inoculation. After 2 weeks, carry out salt stress treatment (soak the potted plants in 200 mM / L NaCl solution for 30 min). After 4 weeks, harvest the seedlings and measure the plant height, stem diameter, and fresh and dry weight of the above-ground parts.

[0051] The result is Figure 9 As shown in A-9E, under salt stress, alfalfa seedlings had significantly higher plant height, stem diameter, aboveground fresh weight, and aboveground dry weight than the control group (CK). Salt stress can significantly improve seedling growth indicators.

[0052] Example 6 Specificity test for strain RH34 The preparation of RH34 bacterial solution is the same as the method in Example 3. Barley and tomato seeds are selected, and pots are prepared. The potting soil system is consistent with that in Example 5. A 140 mmol / L NaCl solution is directly poured into the pots, and the soil matrix is poured through, so that the salt concentration of the pots is maintained at 200 mmol / L when the water content is 70%. The tomato and barley are soaked in the RH34 bacterial solution and water for 8 hours, respectively, and then directly sowed in the pots (9 per pot). It should be noted that, since the germination and growth are carried out under salt stress conditions, the weight of the pots is recorded on the day of sowing the seeds, and then the weight is measured and watered to the initial weight of the pots every day. The seed germination is observed and recorded every day, and the aboveground biomass is measured after 4 weeks.

[0053] The results are shown in Figure 10 A, it can be seen that the aboveground biomass of the tomato seedlings after soaking in the RH34 bacterial solution is lower than that of the CK control, and the aboveground biomass of the barley seedlings after soaking in the RH34 bacterial solution is slightly higher than that of the CK control, but there is no significant difference (see Figure 10 B).

[0054] Therefore, under salt stress conditions, the barley and tomato seedlings after soaking in the RH34 bacterial solution do not show significant promotion of the growth of the seedlings, indicating that the promotion of the growth of the alfalfa seedlings by the strain RH34 has significant specificity.

[0055] Finally, it should be noted that the above content is only used to illustrate the technical solutions of the present application, and is not a limitation on the protection scope of the present application. Simple modifications or equivalent replacements of the technical solutions of the present application made by those skilled in the art do not deviate from the essence and scope of the technical solutions of the present application.

Claims

1. A strain of Sarcina RH34, characterized by: Sporosarcina sp. ) the following characteristics: The Sporosarcina sp. strain RH34 is preserved in the China General Microbiological Culture Collection Center, located at No. 1, Beichen West Road, Yuanmingyuan District, Beijing, on December 25, 2024, and has a preservation number of CGMCC NO. 33199.

2. Application of the Sporosarcina sp. strain RH34 of claim 1 to improve seed germination indexes of alfalfa under salt stress.

3. Use according to claim 2, characterized in that: The salt stress is 200 mmol / L NaCl stress, and the germination indexes include germination energy, germination rate, germination index, radicle length, plumule length, and fresh weight of group seedlings.

4. Use according to claim 2, characterized in that: The salt stress is 250 mmol / L NaCl stress, and the germination indexes include germination rate, radicle length, plumule length, and fresh weight of group seedlings.

5. Application of the Sporosarcina sp. strain RH34 of claim 1 to improve growth conditions of alfalfa seedlings under salt stress.

6. Use according to claim 5, characterized in that: The salt stress is 200 mmol / L NaCl stress, and the growth conditions of the seedlings include plant height, stem diameter, fresh weight of aboveground parts, and fresh dry weight of aboveground parts.

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