Phosphorus-solubilizing growth-promoting bacterium based on burkholderia paragallinarum and application of phosphorus-solubilizing growth-promoting bacterium

Abstract

The invention discloses a phosphorus-solubilizing growth-promoting bacterium. The phosphorus-solubilizing growth-promoting bacterium is burkholderia paragallinarum of which the preservation number is CGMCC (China General Microbiological Culture Collection Center) No.35245. According to the invention, the burkholderia parasuis with efficient phosphorus-dissolving and growth-promoting functions is found through research, and the burkholderia parasuis can effectively promote absorption of plants to phosphorus in a low-phosphorus environment and secrete heteroauxin to promote biomass growth and root growth of the plants. The liquid or solid microbial preparation is prepared and applied to crop planting, the content of available phosphorus in soil can be effectively increased, the micro-ecological structure of the soil can be improved, the use amount of chemical phosphate fertilizer can be reduced, and remarkable economic and ecological benefits are achieved.

Description

TECHNICAL FIELD

[0002] The present application relates to the field of microorganisms, in particular to a phosphate-solubilizing and growth-promoting bacterium based on Paraburkholderia sp. isolated from the rhizosphere of Phyllostachys heteroclada and Phyllostachys pubescens mixed forest and application thereof. BACKGROUND

[0004] Plants require a large amount of phosphorus during growth, and phosphorus is a basic component of biological molecules such as nucleic acids, phospholipids, and ATP, and plays an important role in energy metabolism, photosynthesis, root development, and yield formation of plants. However, although the total phosphorus content in soil is abundant, most of it exists in the form of inorganic phosphorus (such as tricalcium phosphate, ferric phosphate, and aluminum phosphate) or organic phosphorus, which is difficult for plants to directly absorb and utilize. The proportion of soluble phosphorus is usually less than 1% to 2% of the total phosphorus. Therefore, the lack of phosphorus availability has become one of the main nutritional bottlenecks limiting the high and stable yield of crops.

[0005] To increase the content of available phosphorus in soil, chemical phosphorus fertilizer is usually applied in agricultural production to supplement phosphorus sources. However, chemical phosphorus fertilizer is easily fixed in soil, and the utilization rate is only 10% to 25%, and the remaining part is easy to cause resource waste and environmental pollution. In addition, long-term application of chemical fertilizer can destroy the structure of soil microbial community, leading to soil compaction and decline in soil fertility, which is not conducive to the sustainable development of agriculture.

[0006] In recent years, microbial fertilizer has attracted widespread attention as a green, environmentally friendly, and sustainable new type of agricultural input. Among them, phosphate-solubilizing microorganisms (PSMs) can convert insoluble inorganic phosphorus into soluble phosphorus by secreting organic acids, enzymes, and chelating agents, and some strains can also produce indole acetic acid (IAA), gibberellin, and other plant growth-promoting substances, playing a dual role of phosphate solubilization and growth promotion. Common phosphate-solubilizing microorganisms include Pseudomonas (Pseudomonas sp.), Bacillus (Bacillus sp.), Burkholderia (Burkholderia sp.), and Aspergillus (Aspergillus sp.), etc. Pseudomonas Bacillus Burkholderia Aspergillus

[0007] However, the existing phosphate-solubilizing bacteria have problems such as low phosphate-solubilizing efficiency, poor environmental adaptability, and insufficient stability, especially under adverse conditions such as high salt, alkaline, or low temperature, the phosphate-solubilizing activity significantly decreases, and it is difficult to maintain stable effects in different regions and soil types. Therefore, screening excellent strains with high phosphate-solubilizing capacity, broad-spectrum environmental adaptability, and growth-promoting activity is the key direction of current research and application of microbial fertilizer.

[0008] Paraburkholderia (Paraburkholderia sp.) Paraburkholderia ​​​​It is a gram-negative bacillus and widely exists in the rhizosphere environment of plants. Some strains have the functions of nitrogen fixation, phosphorus dissolution, disease resistance and growth promotion. However, there are few reported strains of Burkholderia paraputida that can dissolve phosphorus and promote growth, and systematic research and agricultural application thereof are still in the initial stage.

[0009] Therefore, it is of important theoretical significance and practical value to develop a strain of Burkholderia paraputida with high phosphorus dissolution capacity and plant growth promotion effect, and verify the application value thereof in improving phosphorus absorption and promoting growth of crops.

[0010] To solve the above problems, the present application isolates and screens a strain of Burkholderia paraputida suitable for southern acidic soil and having strong phosphorus dissolution and release capacity from the rhizosphere soil of Cunninghamia lanceolata-Forest mixed forest. Paraburkholderia sediminicola The present application enriches the strain resource of fertilizer that can be practically used and helps the economic development of green ecological forestry. SUMMARY

[0012] To solve the above defects, the present application provides a phosphorus-dissolving and growth-promoting bacterium based on Burkholderia paraputida as well as a preparation method and application thereof. The present application provides the following technical solutions. On one hand, the present application provides a phosphorus-dissolving and growth-promoting bacterium, which is Burkholderia paraputida with the preservation number of CGMCC No.35245. Paraburkholderia sediminicola ).

[0013] According to the present application, the total number of viable bacteria in the phosphorus-dissolving and growth-promoting bacterium is 5.5×10 6 CFU / mL.

[0014] According to the present application, the phosphorus-dissolving and growth-promoting bacterium has the ability to produce indole acetic acid and promote the growth of plant roots.

[0015] On the other hand, the present application further provides a phosphorus-dissolving and growth-promoting bacterium agent, which comprises the following components by weight percentage: (1) the phosphorus-dissolving and growth-promoting bacterial strain with the preservation number of CGMCC No.35245, accounting for 0.5% to 5% of the total weight; (2) carrier, accounting for 95% to 99.5% of the total weight; the carrier is a mixture of one or more of the following: peat, vermiculite, rice husk powder, wood chip powder, humic acid sodium or inorganic mineral powder.

[0016] On the other hand, the present application further provides a method for preparing the above-mentioned phosphorus-dissolving and growth-promoting bacterium agent, comprising the following steps: (1) inoculating Burkholderia paraputida with the preservation number of CGMCC No.35245 in a liquid nutrient medium; (2) 28-30℃, 150-200 rpm, 48-72 hours; (3) Collect the bacteria or fermentation liquor after the fermentation is completed; (4) Mix the bacteria with a carrier, or directly use the fermentation liquor to obtain the phosphorus-dissolving and growth-promoting bacteria agent.

[0017] According to the present application, the liquid nutrient medium comprises the following components: C6H 12 O610 g / L, Ca3(PO4)25 g / L, (NH4)2SO40.5 g / L, NaCl 0.3 g / L, MgSO40.3 g / L, KCl 0.3 g / L, MnSO40.03 g / L, FeSO40.03 g / L, agar 15 g / L, and pH is adjusted to 6.5-7.0.

[0018] In another aspect, the present application also provides the application of the phosphorus-dissolving and growth-promoting bacteria agent in promoting the absorption of phosphorus by plants, the high-efficiency nitrogen-fixing bacteria being the Paraburkholderia sp. with the preservation number of CGMCC No.35245, which can promote the absorption of phosphorus by plants in a low-phosphorus environment and secrete indole acetic acid to promote the biomass growth and root growth of plants.

[0019] In another aspect, the present application also provides the application of the phosphorus-dissolving and growth-promoting bacteria in promoting the development of plant roots.

[0020] In another aspect, the present application also provides the application of the phosphorus-dissolving and growth-promoting bacteria in improving the biomass of plants.

[0021] According to the present application, the above-mentioned plants are Arabidopsis thaliana or Cunninghamia lanceolata.

[0022] The present application finds a Paraburkholderia sp. with high efficiency in dissolving phosphorus and promoting growth, which can effectively promote the absorption of phosphorus by plants in a low-phosphorus environment and secrete indole acetic acid to promote the biomass growth and root growth of plants. By preparing into a liquid or solid microbial preparation and applying in crop planting, the soil effective phosphorus content can be effectively improved, the soil micro-ecological structure can be improved, and the use amount of chemical phosphorus fertilizer can be reduced, which has significant economic and ecological benefits. If the phosphorus-dissolving and growth-promoting bacteria is introduced into southern Cunninghamia lanceolata forest land, the soil phosphorus availability can be effectively improved, and the growth environment of the trees can be improved, which provides a new technical means for realizing the sustainable development of Cunninghamia lanceolata artificial forest.

[0023] Biological preservation The Paraburkholderia sp. of the present application Paraburkholderia sediminicola) was deposited at China General Microbiological Culture Collection Center (CGMCC) on July 16, 2025, and the deposit number is CGMCC No. 35245 (address: No. 1, Beichen West Road, Yard 3, Chaoyang District, Beijing, 100101, P. R. China). BRIEF DESCRIPTION OF DRAWINGS

[0025] In order to more clearly illustrate the embodiments or technical solutions of the present application, the present application will be further described below with reference to the drawings, which are used to explain the technical principles and specific embodiments of the present application, but do not constitute a limitation on the present application.

[0026] Figure 1 The figure is a phosphorus-dissolving ring of the phosphorus-dissolving bacterial agent of the present application.

[0027] Figure 2 The figure is an effective phosphorus content of the phosphorus-dissolving bacteria of the present application.

[0028] Figure 3 The figure is a biofilm of the phosphorus-dissolving bacteria of the present application.

[0029] Figure 4 The figure is the growth status of Arabidopsis thaliana root under the treatment of the phosphorus-dissolving bacterial agent of the present application (A: normal 1 / 2MS + sterile water treatment; B: normal 1 / 2MS + phosphorus-dissolving bacteria treatment; C: low-phosphorus 1 / 2MS + sterile water treatment; D: low-phosphorus 1 / 2MS + phosphorus-dissolving bacteria treatment).

[0030] Figure 5 The figure is a statistical chart of photosynthetic indicators of Cunninghamia lanceolata seedlings under the treatment of the phosphorus-dissolving bacterial agent of the present application (A: net photosynthetic rate; B: transpiration rate; C: stomatal conductance). DETAILED DESCRIPTION

[0032] The experimental methods used in the following examples are conventional methods unless otherwise specified.

[0033] The materials, reagents, etc. used in the following examples can be obtained from commercial channels unless otherwise specified.

[0034] The endpoints of the ranges and any values disclosed herein are not limited to the precise values stated. The ranges or values should be construed and understood to include values adjacent and approximating the stated ranges or values. For ranges of values, the endpoints of each range are combined with the endpoints of the other ranges to form new ranges, and the new ranges are to be considered as being specifically disclosed.

[0035] The phosphorus-dissolving growth-promoting bacteria used in the following examples are Burkholderia paraputida (CGMCC No. 35245)Paraburkholderia sediminicola The phosphate-solubilizing bacteria were used at a total viable count concentration of 5.5 × 10⁻⁶. 6 A bacterial suspension of CFU / mL was applied to Arabidopsis thaliana.

[0036] 1. Materials and Methods 1.1 Isolation and Identification of Phosphate-Soluble Bacteria Rhizosphere soil from *Phoebe zhennan* mixed forests in the Zhujiabu area of ​​Xin'anjiang Forest Farm, Jiande City, Zhejiang Province, was collected using a random sampling method and transported back to the laboratory. 5g of soil sample was placed in 50mL of sterile water and shaken in a 28℃, 180rpm incubator for 4-5 days to prepare a soil suspension. A serial dilution method was used to prepare 10... -4 10 -5 Take 0.1 mL of each diluted soil suspension and spread it onto PVK (C6H) solution. 12 The bacteria were isolated on a medium containing 10 g / L O6, 5 g / L Ca3(PO4)2, 0.5 g / L (NH4)2SO4, 0.3 g / L NaCl, 0.3 g / L KCl, 0.3 g / L MgSO4, 0.03 g / L MnSO4, 0.03 g / L FeSO4, and 15 g / L agar, and incubated at 28 °C for 4 days. Each concentration was repeated three times. Colony growth and changes in the clear zone around the colonies were observed. Single colonies with a prominent clear zone were selected and further purified by streak plating. The morphological characteristics of the purified phosphate-solubilizing bacteria colonies were observed, including colony size, shape, color, edge, surface texture, and transparency. The selected strains were identified by 16S rRNA sequencing.

[0037] 1.2 Evaluation of Phosphate-Solubilizing Ability of Phosphate-Solubilizing Bacteria The obtained phosphate-solubilizing bacteria were inoculated into LB liquid medium (10g peptone, 5g yeast extract, 10g sodium chloride, 1L distilled water, pH 7.0-7.2), and cultured at 37℃ and 200 r / min for 1 day. The bacterial concentration was then adjusted to OD using sterile water. 600 =0.5. Take 5 μL of bacterial suspension and inoculate it into PVK medium (C6H). 12 The medium was prepared in triplicate on 10 g / L O6, 5 g / L Ca3(PO4)2, 0.5 g / L (NH4)2SO4, 0.3 g NaCl, 0.3 g / L KCl, 0.3 g / L MgSO4, 0.03 g / L MnSO4, 0.03 g / L FeSO4, and 15 g / L agar. The size of the clear zone was observed and recorded, and the phosphate-solubilizing zone ratio (D / d) was calculated. The phosphate-solubilizing ability of each strain was preliminarily determined based on the D / d value. The medium was prepared in 5 mL PVK liquid medium (C6H4SO4). 12Add 5 μL of bacterial suspension at an inoculum concentration of 0.1% to a solution containing 10 g / L O6, 5 g / L Ca3(PO4)2, 0.5 g / L (NH4)2SO4, 0.3 g / L NaCl, 0.3 g / L KCl, 0.3 g / L MgSO4, 0.03 g / L MnSO4, and 0.03 g / L FeSO4. After incubating at 28°C for 5 days, inject 1 mL of the solution into a sterile centrifuge tube, centrifuge at 4000 rpm for 5 min, and collect the supernatant for testing. Determine the phosphate-solubilizing ability of the strain using the molybdenum antimony colorimetric method.

[0038] Determination of phosphorus content by molybdenum-antimony colorimetric method: KH₂PO₄ was dried continuously at 105℃. 0.44 g of potassium dihydrogen phosphate was dissolved in 100 mL of distilled water, and 5 mL of concentrated sulfuric acid solution was added. The solution was then diluted to 1000 mL with distilled water. 10 mL of this solution was transferred to a 200 mL volumetric flask, and water was added to the mark to prepare a solution with a concentration of 5 mg·L⁻¹. -1 The standard solution was diluted to different concentration gradients (0 mg / L, 0.2 mg / L, 0.4 mg / L, 0.6 mg / L, 0.8 mg / L, 1 mg / L) and a standard curve was plotted.

[0039] Measure 153 mL of concentrated sulfuric acid into a beaker containing 400 mL of distilled water and stir continuously until completely cooled. Grind ammonium molybdate into a fine powder. Prepare 300 mL of RO water at approximately 60°C. Dissolve 10 g of ammonium molybdate in the distilled water and cool to room temperature. Mix the sulfuric acid solution and ammonium molybdate solution thoroughly. Add 100 mL of 0.5% potassium antimony tartrate solution. After cooling, dilute with RO water to 1000 mL and shake well to prepare a molybdenum-antimony stock solution. Weigh 1.5 g of ascorbic acid and dissolve it in 100 mL of the molybdenum-antimony stock solution to prepare a molybdenum-antimony colorimetric reagent. Weigh 0.2 g of 2,4-dinitrophenol and dissolve it in 100 mL of RO water to prepare a 2,4-dinitrophenol indicator.

[0040] Add 100 μL of the supernatant to be tested to a colorimetric tube, and dilute with RO water to 10 mL. Add 2 drops of 2,4-dinitrophenol indicator and 2.5 mL of molybdenum antimony anti-colorimetric reagent, shake well, and bring the volume to 25 mL. Let stand for 30 min. Use a blank solution as a reference to zero the tube, and perform colorimetric analysis at 700 nm. Obtain the available phosphorus content of the strain according to the phosphorus standard curve.

[0041] P – Available phosphorus content, mg / mL; P = K × V1 / V2; K – Concentration obtained from the standard curve, mg / mL; V1 — Volume at final volume, mL; V2 - volume of supernatant added, mL.

[0042] 1.3 Secretion IAA ability determination The isolated phosphate-solubilizing bacteria were inoculated into King's medium containing L-tryptophan (20.0 g of proteose peptone, 1.725 g of K2HPO4, 15.0 mL of glycerol, 1.5 g of MgSO4·7H2O, 0.1 g of L-tryptophan, 1 L of RO water, pH 7.2) and cultured at 37°C for 12 days. After centrifugation at 5000 rpm for 2 minutes, the supernatant was collected into a new sterile centrifuge tube and stored in a refrigerator at 4°C for testing. The supernatant was mixed with Salkowski reagent (1 mL of 0.5 mol / L ferric chloride added to 30 mL of concentrated sulfuric acid, and diluted to 50 mL) at a ratio of 1:1, and the OD was measured after 30 minutes of reaction in the dark. 530 The IAA content was calculated by a standard curve, and three replicates were set.

[0043] IAA standard curve drawing 10 mg of indole acetic acid reference substance was weighed, diluted with 50% methanol, and diluted to 10 mL. The standard solution was diluted with methanol to 10 μg / L, 20 μg / L, 30 μg / L, 40 μg / L, 50 μg / L, and 100 μg / L. The concentration of the standard was taken as the abscissa, and the measured OD value was taken as the ordinate to draw the standard curve.

[0044] 1.4 Biofilm formation ability determination In a 96-well plate, 200 μL of LB medium and 5 μL of bacterial solution with OD 600 = 0.5 were added to each well, three replicates were set for each treatment, and the plate was placed in an 8°C constant temperature incubator for 24 hours. The bacterial solution in the 96-well plate was aspirated with a syringe, and each well was gently washed three times with 200 μL of PBS. The 96-well plate was opened and placed on a clean bench, and the plate was left to dry for 45 minutes. 125 μL of 0.1% crystal violet staining solution was added to each well, and the plate was incubated at room temperature for 15 minutes in the dark. 200 μL of deionized water was aspirated into the microwells with a pipette, and the free dye was washed away slowly. The liquid in the wells was aspirated with a syringe; 200 μL of 95% ethanol was added to the microwells after the 0.1% crystal violet staining solution was aspirated, and the plate was left to stand for 25 minutes. The plate was gently shaken to mix evenly, and the absorbance was measured at 570 nm with a microplate reader.

[0045] The critical value ODc was calculated as follows: ODc = average OD 570 of the control group + 3 × |standard deviation of the control group|; The average OD 570 value of each strain was compared with ODc, and the biofilm formation ability grade was determined according to the classification standard. No biofilm formation ability: OD 570 ≤ ODc; Weak biofilm formation ability: ODc< OD 570 ≤ 2 x ODc; Medium biofilm formation ability: 2 x ODc< OD 570 ≤ 4 x ODc; Strong biofilm formation ability: OD 570 > 4 x ODc; 1.5 Thiobacillus - Arabidopsis plate co-culture Thiobacillus was inoculated in LB liquid medium and cultured at 28°C with 180 rpm shaking for 48 h. 1 mL of bacterial solution was centrifuged at 5000 rpm for 5 min, then resuspended with fresh LB medium and adjusted to OD600=0.5. Four-day-old Arabidopsis seedlings with consistent growth were selected and transplanted into low-phosphorus 1 / 2MS medium containing insoluble calcium phosphate ((-P-N)Ms medium 4.4 g, 7.6% potassium nitrate solution 25 mL, 1.7% potassium dihydrogen phosphate solution 5 mL, 20.625% ammonium nitrate solution 8 mL, calcium phosphate 0.09687 g, sucrose 30 g, agar 8 g, RO water 1 L, pH 5.8-6.0) or normal 1 / 2MS medium (control). 10 μL of adjusted bacterial solution (OD 600 =0.5) was inoculated 3 cm away from the root of the seedling, and the un-inoculated treatment was used as the negative control. All culture dishes were sealed with parafilm and placed vertically in a 23±2°C light incubator for 10 d, then the growth status of Arabidopsis was observed and the biomass was measured.

[0046] 1.6 Cupressus funebris seedling pot experiment One-year-old Cupressus funebris clones with similar growth were selected and transplanted into 20 cm x 25 cm plastic pots. Thiobacillus was pre-cultured in LB medium for 24 h, and the concentration was uniformly adjusted to OD 600 =0.6, and applied to the Cupressus funebris seedlings at a dose of 100 mL per pot, once a week for a total of 4 times. The same concentration of bacterial solution after high-pressure steam sterilization was used as a control treatment, and 3 replicates were set for each group. Three months after inoculation, the photosynthetic indicators of Cupressus funebris were measured in the morning on sunny days. A portable photosynthesis measurement system Li-6800 was used for measurement, and about 5 cm branches were placed in the leaf chamber. Three branches were selected from each Cupressus funebris seedling, with a total of 9 replicates. The conditions were set as CO2 concentration 400 μmol mol -1 , flow rate 400 μmol s -1 , leaf chamber temperature 25°C, and light intensity 600 μmol·m -2 ·s -1The Chinese fir seedlings were taken out of the flowerpots, washed clean of soil, and surface water was absorbed.

[0047] 2 Results and analysis 2.1 Isolation and identification of phosphorus-solubilizing bacteria A phosphorus-solubilizing bacterium numbered P10 was screened from the rhizosphere of Phoebe pygmaea in a mixed forest of Phoebe pygmaea and Phoebe sheareri by using transparent circle screening, and was sent to Yikang Biotechnology Co., Ltd. for sequencing. According to 16S rRNA sequencing and NCBI comparison, the obtained phosphorus-solubilizing bacterium was determined to be Paraburkholderia. Paraburkholderia sediminicola )。

[0048] 2.2 Evaluation of phosphorus-solubilizing capacity The phosphorus-solubilizing capacity of P10 was preliminarily detected by the diameter D / d of the phosphorus-solubilizing circle, and D / d = 1.15 (see Figure 1 ); the phosphorus standard curve equation was y = 0.0971x + 0.0021, R 2 = 0.9952. The molybdenum-antimony anti-colorimetric method was used for quantitative analysis of the phosphorus-solubilizing capacity, and the effective phosphorus increment was 851.12 ± 2.40 mg / L (see Figure 2 ).

[0049] 2.3 Determination of IAA secretion capacity The IAA standard curve equation was y = 0.0176x + 0.0332, R² = 0.99. After P10 was inoculated into King's liquid medium and cultured for 12 days, the IAA content was measured by Salkowski colorimetry at a wavelength of 530 nm, and the IAA content was 22.49 ± 2.54 μg / mL.

[0050] 2.4 Determination of biofilm formation capacity It was found by using the microporous plate crystal violet staining method that P10 had biofilm formation on the microporous plate (see Figure 3 ), so it was judged to have biofilm formation capacity. After the stained biofilm was dissolved in 95% ethanol, the OD 570 = 0.807 ± 0.045, ODc = 0.191 ± 0.008, and OD 570 > 4 × ODc of P10 were measured at a wavelength of 570 nm. Therefore, P10 has strong biofilm formation capacity.

[0051] 2.5 Phosphorus-solubilizing bacteria-plate co-culture with Arabidopsis thaliana P10 and Arabidopsis thaliana were co-cultured on normal (CK) and low-phosphorus (-P) 1 / 2 MS medium, respectively, and morphological observation and biomass statistics were performed after Arabidopsis thaliana was grown for 10 days (see Figure 4, Table 1). P10 promoted the growth of Arabidopsis thaliana under both normal and low-phosphorus culture conditions. In normal 1 / 2 MS medium, P10 promoted the growth of Arabidopsis thaliana, with an increase of 245.95% in whole-plant biomass, 351.13% in aboveground biomass, and 90.51% in underground biomass. Under low-phosphorus culture conditions, the growth of Arabidopsis thaliana without P10 was weak, but the growth of Arabidopsis thaliana co-cultured with P10 was good, with a whole-plant biomass of 21.87±2.78 mg, an aboveground biomass of 13.63±1.87 mg, and a root weight of 8.25±0.91 mg, indicating that P10 strain also had a significant advantage in promoting the biomass of Arabidopsis thaliana under low-phosphorus conditions.

[0052] Table Biomass of Arabidopsis thaliana treated with phosphate-solubilizing bacteria 2.6 Pot experiment of Cunninghamia lanceolata seedlings 2.6.1 Effect of phosphate-solubilizing bacteria treatment on the height, ground diameter, and biomass of Cunninghamia lanceolata seedlings After 3 months of inoculation, the fresh weight of the whole plant, the fresh weight of the aboveground part, and the fresh weight of the underground part of the Cunninghamia lanceolata seedlings were measured, and the results are shown in Table 2. Compared with the control group (CK), the treatment of inoculating phosphate-solubilizing bacteria P10 increased the biomass of the whole plant and the aboveground part, but the biomass of the underground part was slightly lower than that of the control. Therefore, phosphate-solubilizing bacteria had a better promoting effect on the growth of the aboveground part of Cunninghamia lanceolata seedlings.

[0053] Table 2 Fresh weight statistics of Cunninghamia lanceolata Treatment Whole plant fresh weight (g) Aboveground part fresh weight (g) Underground part fresh weight (g) CK 18.83±1.69 12.03±2.80 6.79±1.11 P10 19.20±2.10 13.67±1.55 5.53±0.55 2.6.2 Effect of phosphate-solubilizing bacteria treatment on the photosynthetic indicators of Cunninghamia lanceolata seedlings After 3 months of inoculation, the net photosynthetic rate, transpiration rate, and stomatal conductance of the Cunninghamia lanceolata seedlings were measured, and the results are shown in Table 3. Figure 5 Compared with the control group (CK), the P10 treatment group showed significant improvements in net photosynthetic rate, stomatal conductance, and transpiration rate.

[0054] Specifically, the net photosynthetic rate, transpiration rate, and stomatal conductance of the P10 treatment group were 6.01±0.66 μmol·m⁻²·s⁻¹, 1.78±0.15 μmol·m⁻²·s⁻¹, and 68.12±5.15 μmol·m⁻²·s⁻¹, respectively, which were significantly higher than those of the control group (P<0.001). p These results indicate that the P10 strain treatment can significantly improve the photosynthetic efficiency, stomatal opening degree, and water use efficiency of Cunninghamia lanceolata seedlings, thereby promoting the growth of Cunninghamia lanceolata seedlings.

Claims

1. A phosphate-dissolving growth-promoting bacteria, characterized in that, The phosphorus-dissolving growth-promoting bacteria are Burkholderiapseudoflava with the preservation number of CGMCC No. 35245 Paraburkholderia sediminicola ).

2. The phosphorus-solubilizing growth promoting bacteria according to claim 1, characterized in that, The total number of viable bacteria in the phosphorus-dissolving growth-promoting bacteria is 5.5 x 10 6 CFU / mL. 3.The phosphorus-solubilizing growth-promoting bacteria according to claim 1 or 2, characterized in that, The phosphate-dissolving growth-promoting bacteria have the ability to produce indole acetic acid and promote plant root growth.

4. A phosphorus-dissolving growth promoting microbial agent, characterized by, The bacterial agent comprises the following components by weight percentage: The phosphate-dissolving growth-promoting bacteria strain with the accession number CGMCC No. 35245, 0.5% to 5% of the total weight; (2) carrier, 95% to 99.5% of the total weight; the carrier is one or more of the following: peat, vermiculite, rice husk powder, wood powder, humic acid sodium or inorganic mineral powder.

5. A method of preparing the phosphorus-solubilizing growth promoting bacterial agent according to claim 4, characterized by, The method comprises the following steps: (1) inoculating Paraburkholderia sediminicola with the accession number CGMCC No. 35245 in a liquid nutrient medium; (2) culturing at 28-30°C and 150-200 rpm for 48-72 hours; (3) collecting the bacterial cells or fermentation liquor after the fermentation is completed; (4) mixing the bacterial cells with the carrier or directly using the fermentation liquor to obtain the phosphate-dissolving growth-promoting bacterial agent.

6. The method of claim 5, wherein, The liquid nutrient medium comprises the following components (by weight): C6H 12 O6 10 g / L, Ca3(PO4)2 5 g / L, (NH4)2SO4 0.5 g / L, NaCl 0.3 g / L, MgSO4 0.3 g / L, KCl 0.3 g / L, MnSO4 0.03 g / L, FeSO4 0.03 g / L, pH adjusted to 6.5-7.

0.

7. Use of phosphate-solubilizing growth promoting bacteria for promoting the uptake of phosphorus by plants, characterized in that, The high-efficiency nitrogen-fixing bacteria are Paraburkholderia sediminicola with the accession number CGMCC No. 35245, which can promote the absorption of phosphorus by plants in a low-phosphorus environment and secrete indole acetic acid to promote the growth of plant biomass and root growth.

8. The phosphate-dissolving growth-promoting bacteria of claim 1 are used for promoting the development of plant roots.

9. The phosphate-dissolving growth-promoting bacteria of claim 1 are used for increasing plant biomass.

10. Use according to any one of claims 7 to 9, characterized in that, The plant is Arabidopsis thaliana or Cunninghamia lanceolata.

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