Application of bacillus Cdb8-1 in improving saline-alkaline tolerance of colored-leaf poplar

Abstract

The invention provides application of bacillus Cdb8-1 to improvement of saline-alkaline tolerance of colored-leaf poplar, and belongs to the technical field of microorganism application. According to the invention, the existing strain bacillus Cdb8-1 is developed, and the strain is found to be capable of improving the saline-alkaline tolerance of the colored-leaf poplar, so that the living space of the colored-leaf poplar is greatly expanded, and a new thought is provided for improvement and utilization of saline-alkali soil.

Description

Technical Field

[0001] The invention relates to the technical field of microbial application, and in particular to application of Bacillus Cdb8-1 in improving the salt-alkali tolerance of colorful poplar. Background Art

[0002] Soil salinization is an important factor that restricts agricultural and forestry production and the ecological environment, and is a global problem. In arid and semi-arid areas, about 50% of irrigated land is affected by salinization. Non-arid and semi-arid areas also experience salinization, which seriously affects the growth and yield of crops and greatly hinders the sustainable development of the agricultural and forestry economy and the ecological environment. Developing and utilizing large areas of saline-alkali land, desertified land and abundant salt water resources to develop agricultural and forestry production is an urgent problem to be solved.

[0003] Salt-alkali stress seriously hinders almost all important life processes in plant growth and development, including growth and development, photosynthesis, protein synthesis, lipid metabolism, etc., and further leads to plant aging and death. Therefore, improving the salt-alkali tolerance of plants is of great significance to the development of agriculture and forestry.

[0004] The improvement of saline-alkali land is an important breakthrough in increasing the area of ​​arable land and restoring the ecology of arable land, and it has great potential for governance. Chemical improvement is to achieve the purpose of treating salinized soil by adding new chemical substances to the salinized soil. This method is quick to take effect but it is easy to introduce a large number of new chemical substances into the environment, causing secondary pollution. Physical improvement mainly focuses on the construction of a large number of water conservancy facilities and using water to remove a large amount of salt from the soil. However, this technical means has the disadvantages of large engineering workload, high investment cost, and unsustainability. Compared with chemical and physical improvements, biological remediation has the advantages of energy saving, high efficiency and economy, strong durability, and stable improvement effect. It is an important research direction for saline-alkali soil improvement.

[0005] As people's green environmental protection concept is strengthened, plant growth-promoting rhizobacteria (PGPR) are increasingly used in the study of saline-alkali soil improvement. PGPR can promote plant growth by secreting the plant growth hormone indole-3-acetic acid (IAA); it can produce extracellular polysaccharides, form soil aggregates with soil particles, increase soil permeability, and improve soil structure; it can also dissolve phosphorus and potassium, and improve soil nutrient utilization. Among them, Bacillus grows fast, has simple nutritional requirements, and can produce spores with strong stress resistance, which makes the batch production process of Bacillus preparations simple, the fermentation production cost is low, the preparation application is convenient, and the product has a long storage period. It is an ideal microbial preparation for saline-alkali soil remediation. However, there are still deficiencies in this field, such as a small number of strains and poor adaptability of existing strains to special environments, especially saline-alkali soil environments. Therefore, the development of salt-alkali tolerant growth-promoting strains and their application in plant growth promotion and improvement of saline-alkali soils is very important. Summary of the invention

[0006] The purpose of the invention is to develop salt-alkali tolerant growth-promoting strains, improve the salt-alkali tolerance of colorful poplars, and expand the living space of colorful poplars.

[0007] In order to achieve the above-mentioned object of the invention, the present invention provides the following technical solutions:

[0008] The invention provides an application of Bacillus nitratirecucens Cdb8-1 in improving the salt-alkali tolerance of colorful poplar.

[0009] Preferably, the colorful poplars include Zhongshan Caiyun and Lianghong Poplar.

[0010] The present invention develops the existing bacterial strain Bacillus Cdb8-1 and finds that the strain can improve the salt-alkali tolerance of colorful poplar, which greatly expands the living space of colorful poplar and provides a new idea for the improvement and utilization of saline-alkali land. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 Fresh weight of Zhongshan Caiyun and Lianghong Poplar seedlings after 4 weeks of treatment with 500mL 200mM NaCl and 500mL 200mM NaCl + 20mL suspended bacteria;

[0012] Figure 2 The height of Zhongshan Caiyun and Lianghong Poplar seedlings after 4 weeks of treatment with 500mL 200mM NaCl and 500mL 200mM NaCl + 20mL suspended bacteria.

[0013] Figure 3The root weight of Zhongshan Caiyun and Lianghong Poplar seedlings after 4 weeks of treatment with 500mL 200mM NaCl and 500mL 200mM NaCl + 20mL suspended bacteria.

[0014] Figure 4 The root length of Zhongshan Caiyun and Lianghong Poplar seedlings after 4 weeks of treatment with 500mL 200mM NaCl and 500mL 200mM NaCl + 20mL suspended bacteria;

[0015] Figure 5 The chlorophyll content of Zhongshan Caiyun and Lianghong Poplar seedlings after 4 weeks of treatment with 500mL 200mM NaCl and 500mL 200mM NaCl + 20mL suspended bacteria;

[0016] Figure 6 Fv·Fm of Zhongshan Caiyun and Lianghong Poplar seedlings after 4 weeks of treatment with 500mL 200mM NaCl and 500mL 200mM NaCl + 20mL suspended bacteria -1 value;

[0017] Figure 7 The malondialdehyde content of Zhongshan Caiyun and Lianghong Poplar seedlings after 4 weeks of treatment with 500mL 200mM NaCl and 500mL 200mM NaCl + 20mL suspended bacteria;

[0018] Figure 8 The proline concentration of Zhongshan Caiyun and Lianghong Poplar seedlings after 4 weeks of treatment with 500mL 200mM NaCl and 500mL 200mM NaCl + 20mL suspended bacteria;

[0019] Fig. 9 The SOD activity of Zhongshan Caiyun and Lianghong Poplar seedlings after 4 weeks of treatment with 500mL 200mM NaCl and 500mL 200mM NaCl + 20mL suspended bacteria.

[0020] Fig.10 The CAT activity of Zhongshan Caiyun and Lianghong Poplar seedlings after 4 weeks of treatment with 500mL 200mM NaCl and 500mL 200mM NaCl + 20mL suspended bacteria.

[0021] Fig.11 The POD activity of Zhongshan Caiyun and Lianghong Poplar seedlings after 4 weeks of treatment with 500mL 200mM NaCl and 500mL 200mM NaCl + 20mL suspended bacteria.

[0022] Fig.12The hydrogen peroxide content of Zhongshan Caiyun and Lianghong Poplar seedlings after 4 weeks of treatment with 500mL 200mM NaCl and 500mL 200mM NaCl + 20mL suspended bacteria;

[0023] Fig.13 The superoxide anion content of Zhongshan Caiyun and Lianghong Poplar seedlings after 4 weeks of treatment with 500mL 200mM NaCl and 500mL 200mM NaCl + 20mL suspended bacteria. DETAILED DESCRIPTION

[0024] The technical solutions provided by the present invention are described in detail below in conjunction with the embodiments, but they should not be construed as limiting the protection scope of the present invention.

[0025] The Bacillus nitratirecucens Cdb8-1 used in the present invention and the following examples was donated by Anhui Normal University, and the deposit number of the strain is CCTCC M 20231655.

[0026] Example 1

[0027] (1) Inoculate LB medium with 2% of the fresh culture of Bacillus nitratirecucens Cdb8-1 from overnight culture and culture it in a constant temperature shaker at 28°C and 200 rpm / min for 16 hours. Collect the cells by centrifugation at 10000 rpm / min for 5 minutes, wash the cells three times with sterile water, and resuspend them in sterile water to prepare a final concentration of 6.4×10 7 CFU / mL of suspended bacteria were used for subsequent experimental treatments.

[0028] (2) Prepare 200 mM NaCl solution for subsequent experimental treatments.

[0029] (3) 20 days after cutting, Zhongshan Caiyun and Lianghong Poplar seedlings were treated with 500mL 200mM NaCl and 500mL 200mM NaCl + 20mL suspended bacteria, respectively. During the treatment, the NaCl solution and suspended bacteria were applied with watering. When 500mL 200mM NaCl + 20mL suspended bacteria were treated, the two solutions were fully mixed and then applied to the seedlings. The size of the pots used in the experiment was 12.5 cm in bottom diameter, 16.5 cm in height, and 16 cm in diameter. There were holes and trays at the bottom of the pots, and each pot was filled with 1600 grams of soil. Daily management such as watering and weeding was carried out every week. After 4 weeks, the external morphological indicators such as fresh weight, plant height, and root length of the two treatments of the two colorful leaf poplar varieties were counted, the difference in chlorophyll content, the difference in physiological indicators such as malondialdehyde, proline, and oxidoreductase (SOD, CAT, POD) activity, and the difference in the content of hydrogen peroxide and superoxide anion were calculated.

[0030] Determination of chlorophyll fluorescence and determination of chlorophyll fluorescence parameters using

[0031] FMS-2 pulse modulated fluorescence instrument (UK), the measurement and light response curve are carried out simultaneously, the marked leaves are measured, and the average value is taken as the measurement value. First, the parameters under light reaction are measured, and after the measurement, the light hole is closed. After dark treatment for 30 minutes, the fluorescence parameters under dark reaction are measured. The maximum photochemical efficiency of PSII: Fv / Fm=(Fm-Fo) / Fm;

[0032] Weigh the leaves of poplar seedlings under different treatments, remove the veins, cut and wash the leaves. Collect the leaf fragments and place them in 80% acetone at 28°C in the dark for 24 hours until the leaves turn white to ensure that the chlorophyll is completely extracted. Collect the chlorophyll extract for quantification, and take 3 ml of the chlorophyll extract to colorimetrically measure the absorbance at wavelengths of 663nm, 645nm and 470nm and calculate the total chlorophyll content. Use 80% acetone as a blank control.

[0033] Malondialdehyde (MDA) content determination

[0034] 1. Cut a leaf from the same part of each plant, mix and sample 0.1g, cut it into pieces, add 2mL 10% trichloroacetic acid and a small amount of quartz sand, grind it into a homogenous slurry, and then add 8mL 10% trichloroacetic acid for further grinding. Transfer the homogenate to a 10mL centrifuge tube and centrifuge it at 4000rpm / min for 10min. The supernatant is the malondialdehyde extract.

[0035] 2. Color reaction and determination: Take 4 clean test tubes, number them, 3 of them are sample tubes (three replicates), add 2mL of malondialdehyde extract to each, 1 is a control tube, add 2mL of ultrapure water, then add 2mL of 0.6% thiobarbituric acid solution to each tube, shake well. The mixed solution reacts in a boiling water bath for 10min (start timing from the appearance of small bubbles in the solution in the test tube), take out the test tube and cool it quickly, centrifuge it at 4000rpm / min for 10min, take the supernatant and measure the absorbance (A) value at 532nm, 450nm and 600nm wavelengths respectively.

[0036] 3. Calculation of results: MDA concentration calculation formula: C MDA =6.45(A 532 -A 600 )-A 450 (μmol / L), where A 450 , A 532 and A 600 is the absorbance value measured at 450nm, 532nm and 600nm wavelength. MDA content (μmol / LFW) = (C MDA * Extract volume) / (leaf fresh weight*1000).

[0037] Determination of Proline (Pro) Content

[0038] 1. Extraction of proline: Select leaves from the same position of each plant, mix and sample 0.1g, cut into pieces, and place them in stoppered test tubes respectively. Then add 5mL of 3% sulfosalicylic acid solution to each tube, extract in a boiling water bath for 10min (shake frequently during the extraction process), filter into a clean test tube after cooling, and the filtrate is the proline extract.

[0039] 2. Determination of proline: Pipette 2mL of proline extract into a stoppered test tube, add 2mL of glacial acetic acid and 2mL of 2.5% acidic ninhydrin reagent, and heat in a boiling water bath for 30min. The solution will turn red. After cooling, add 4mL of toluene, shake for 30s, let stand for a while, take the upper layer of liquid into a 10mL centrifuge tube, and centrifuge at 3000rpm / min for 5min. Use a pipette to gently pipette the upper proline red toluene solution into a colorimetric cup, use the toluene solution as a blank control, and measure the absorbance value at a wavelength of 520nm.

[0040] 3. Result calculation: Find the proline content X in the sample solution from the standard curve and calculate the proline content according to the following formula.

[0041] Proline content (μg / g FW) = (X*total amount of extract) / (fresh weight of sample*volume of extract during measurement).

[0042] Superoxide dismutase (SOD) activity assay:

[0043] 1. Weigh the empty tube of a 1.5 mL centrifuge tube, then take about 100 mg of colorful poplar leaves and put them into a 1.5 mL centrifuge tube for liquid nitrogen grinding. Add 1.5 mL of 1 / 15 mol / L phosphate buffer (pH 7.8) and place at 4 ° C for 30 min, then use a 4 ° C centrifuge at 11000 rpm for 20 min, and use a pipette to aspirate the supernatant and place it in a new 1.5 mL pre-cooled centrifuge tube as a crude enzyme solution.

[0044] 2. Dilute the crude enzyme solution 5 times with 1 / 15M phosphate buffer, take 0.5mL and put it in a new 2mL centrifuge tube, add 1.5mL SOD reaction solution, and react in a 6-level light incubator at 30℃ for 10min. Immediately terminate the reaction and read its absorbance at 560nm immediately, marked as A2. 0.5mL double distilled water (H2O) and 1.5mL SOD reaction solution were mixed as a control, marked as A1, and 0.5mL diluted enzyme solution was mixed with 1.5mL H2O to adjust to zero.

[0045] 3. Calculation of enzyme activity: ΔA = (A1-A2) / A1; SOD activity = (N×ΔA) / (W×T×50%), where A1: control reaction value; A2: reaction value after adding enzyme solution; N: dilution factor; W: material weight, g; T: reaction time, min.

[0046] Catalase (CAT) activity assay

[0047] 1. The extraction of crude enzyme solution was the same as above, so the crude enzyme solution was directly used to determine the CAT activity.

[0048] 2. CAT enzyme activity determination: Take 3 mL of 20 mmol / L hydrogen peroxide solution and add it to a 10 mL test tube, add 50 μL of crude enzyme solution and quickly mix, then transfer to a quartz colorimetric cup, and measure the absorbance value A at a wavelength of 240 nm. Measure continuously for 1-3 minutes and record the initial value (A initial and A final).

[0049] 3. Calculation of CAT enzyme activity: One unit of catalase activity was defined as an absorbance change of 0.001 per minute per gram fresh weight (FW) of leaf sample.

[0050] CAT enzyme activity calculation formula: CAT activity = (ΔA 240 *V) / (0.001*t*Vs*W), where ΔA 240 : absorbance change of the reaction mixture (Ainitial-Afinal); t: enzymatic reaction time; V: total volume of sample extract; Vs: volume of sample extract taken during determination; W: sample mass.

[0051] Peroxidase (POD) activity assay

[0052] 1. Extraction of crude enzyme solution: Use the above crude enzyme solution.

[0053] 2. POD enzyme reaction system and sample addition order: 3 mL of 25 mmol / L guaiacol solution, 0.2 mL of 250 mmol / L hydrogen peroxide solution, and 0.1 mL of crude enzyme solution. Record the absorbance of the reaction system at a wavelength of 470 nm every 30 seconds starting from 30 seconds after the addition of the crude enzyme solution, and measure continuously for 10 minutes.

[0054] 3. Calculation of POD enzyme activity: One unit of peroxidase activity is defined as the absorbance change per gram fresh weight (FW) of leaf sample increasing by 0.001 per minute.

[0055] POD enzyme activity calculation formula: POD activity = (ΔA 470 *V) / (W*Vs*0.001*t), where ΔA 470 : absorbance change of the reaction mixture; V: total volume of sample extract; W: sample mass; Vs: volume of sample extract taken during determination; t: enzymatic reaction time.

[0056] Determination of H2O2 content

[0057] The determination was carried out with reference to the method of Christense et al. (1997). Take leaves of poplar seedlings under different treatments, remove the veins and weigh about 0.5g, record the specific weight, grind into a homogenate in a pre-cooled 0.1% trichloroacetic acid (TCA) ice bath, pipette into a centrifuge tube, then rinse the mortar with trichloroacetic acid several times, and pipette into the above centrifuge tube, centrifuge at 1200g for 10min at 4℃, discard the precipitate and keep the supernatant. Take 1ml of the supernatant, add 0.1ml of 95% hydrochloric acid solution containing titanium tetrachloride (TiCl4) (containing 20% ​​w / v TiCL4) solution in sequence, add 0.2ml of ammonia water (NH4OH) while mixing, let it stand for 2min, centrifuge at 1000g for 10min at 4℃, discard the supernatant and keep the precipitate, wash the above precipitate with pre-cooled acetone for at least 3 times to ensure that the precipitate is colorless. Finally, add 1mol·L -1 After dissolving the precipitate with 3 ml of sulfuric acid, the volume was adjusted to 5 ml. The resulting solution was colorimetrically analyzed at a wavelength of 415 nm and the H2O2 content was calculated.

[0058] O2 - Determination of production rate

[0059] According to the method reported by Schneider et al., leaves of poplar seedlings under different treatments were taken, and about 0.5 g of leaves were weighed after removing the veins. The specific weight was recorded and the extract was added with phosphate buffer solution (65 mmol·L -1, pH 7.8) 5ml was fully ground into a homogenate on an ice bath, and the mixture was centrifuged at 4°C with a centrifuge at 5000g / mi and a centrifugation time of 15min. The precipitate was discarded and the supernatant was retained, and the quantification was re-made into 5ml. Then 0.5ml of the supernatant was aspirated and 0.5ml of the reaction solution was added with phosphate buffer solution (65mmol·L -1 , pH 7.8) and 1 ml of hydroxylamine hydrochloride (10 mmol·L -1 ), mixed and placed at room temperature for about 1 hour, then 1 ml of p-aminobenzenesulfonic acid (17 mmol·L -1 ) and add 1 ml of α-naphthylamine (7 mmol·L -1 ), and the mixture was reacted at room temperature for about 20 minutes. Finally, the mixture was added with an equal volume of ether and mixed well, and centrifuged at room temperature for 3 minutes on a centrifuge with a centrifugal force of 3000g. The supernatant (pink) after stratification was aspirated with a pipette and the A530 value was measured colorimetrically at a wavelength of 530nm. The blank control was set to phosphate buffer solution. According to the NO2 - The standard curve is used to calculate O2 - The content.

[0060] result

[0061] (1) Figure 1 As shown, the fresh weight of Zhongshan Caiyun and Lianghong Poplar seedlings after 4 weeks of treatment with 200mM NaCl was 3.86g and 3.47g, respectively. Compared with the fresh weight of Zhongshan Caiyun and Lianghong Poplar seedlings after 4 weeks of treatment with 200mM NaCl, the fresh weight of Zhongshan Caiyun and Lianghong Poplar seedlings treated with 200mM NaCl+20mL suspended bacteria was significantly increased, which were 5.23g and 4.66g, respectively.

[0062] (2) Figure 2 As shown, the heights of Zhongshan Caiyun and Lianghong Poplar seedlings after 4 weeks of 200mM NaCl treatment were 13.5cm and 12.4cm, respectively. Compared with the heights of Zhongshan Caiyun and Lianghong Poplar seedlings after 4 weeks of 200mM NaCl treatment, the heights of Zhongshan Caiyun and Lianghong Poplar seedlings treated with 200mM NaCl+20mL suspended bacteria were significantly increased, which were 16.2cm and 14.3cm, respectively.

[0063] (3) Figure 3As shown, the root weights of Zhongshan Caiyun and Lianghong Poplar seedlings after 4 weeks of treatment with 200mM NaCl were 0.53g and 0.47g, respectively. Compared with the root weights of Zhongshan Caiyun and Lianghong Poplar seedlings after 4 weeks of treatment with 200mM NaCl, the root length and root weight of Zhongshan Caiyun and Lianghong Poplar seedlings treated with 200mM NaCl+20mL suspended bacteria were significantly increased, which were 0.72g and 0.58g, respectively.

[0064] (4) Figure 4 As shown, the root lengths of Zhongshan Caiyun and Lianghong Poplar seedlings after 4 weeks of treatment with 200mM NaCl were 6.2cm and 5.6cm, respectively. Compared with the root lengths of Zhongshan Caiyun and Lianghong Poplar seedlings after 4 weeks of treatment with 200mM NaCl, the root lengths of Zhongshan Caiyun and Lianghong Poplar seedlings treated with 200mM NaCl+20mL suspended bacteria were significantly increased, reaching 8.3cm and 7.1cm, respectively.

[0065] (5) Figure 5 , 6 As shown in the figure, the chlorophyll contents of Zhongshan Caiyun and Lianghong Yang seedlings after 4 weeks of 200 mM NaCl treatment were 3.23 mg.g -1 and 2.03mg.g -1 , Fv.Fm -1 The values ​​were 0.62 and 0.53, respectively, which were comparable to the chlorophyll content, Fv.Fm -1 Compared with the values, the chlorophyll contents of Zhongshan Caiyun and Lianghong Yang seedlings treated with 200mM NaCl + 20mL suspended bacteria were 4.56mg.g -1 and 2.69mg.g -1 ) and Fv.Fm-1 values ​​were significantly increased (0.83 and 2.69, respectively).

[0066] (6) Figure 7 As shown in Figure 2, the MDA contents of Zhongshan Caiyun and Lianghong Poplar seedlings after 4 weeks of 200 mM NaCl treatment were 14.6 μmol.g -1 and 13.5 μmol.g -1 Compared with the MDA content of Zhongshan Caiyun and Lianghong Poplar seedlings treated with 200 mM NaCl for 4 weeks, the MDA content of Zhongshan Caiyun and Lianghong Poplar seedlings treated with 200 mM NaCl + 20 mL suspended bacteria was significantly reduced to 12.5 μmol.g -1 and 12.8 μmol.g -1 .

[0067] (7) Figure 8 As shown in Figure 2, the proline concentrations of Zhongshan Caiyun and Lianghong Poplar seedlings after 4 weeks of 200 mM NaCl treatment were 28.4 μg.g-1 and 24.3 μg.g -1 Compared with the proline concentration of Zhongshan Caiyun and Lianghong Yang seedlings treated with 200mM NaCl for 4 weeks, the proline concentration of Zhongshan Caiyun and Lianghong Yang seedlings treated with 200mM NaCl+20mL suspended bacteria was significantly increased, which was 32.7μg.g -1 and 30.4 μg.g -1 .

[0068] (8) Figures 9-11 As shown in Tables 1 to 3, compared with the SOD, CAT, and POD enzyme activities of Zhongshan Caiyun and Lianghong Poplar seedlings treated with 200 mM NaCl for 4 weeks, the SOD, POD, and CAT enzyme activities of Zhongshan Caiyun and Lianghong Poplar seedlings treated with 200 mM NaCl + 20 mL suspended bacteria were significantly increased.

[0069] Table 1 SOD activity

[0070] <![CDATA[SOD(U·g -1 FW)]]> Zhongshan Color Rhythm Beautiful red poplar 200mM NaCl 264.5 243.2 200mMNaCl+bacterial liquid 305.8 265.7

[0071] Table 2 CAT activity

[0072] <![CDATA[CAT(U·g -1 FW)]]> Zhongshan Color Rhythm Beautiful red poplar 200mM NaCl 87.4 74.5 200mMNaCl+bacterial liquid 98.2 88.7

[0073] Table 3 POD activity

[0074] <![CDATA[POD(U·g -1 FW)]]> Zhongshan Color Rhythm Beautiful red poplar 200mM NaCl 264.3 243.6 200mMNaCl+bacterial liquid 305.4 265.2

[0075] (9) Figures 12-13 As shown in Tables 4 to 5, compared with the hydrogen peroxide and superoxide anion contents of Zhongshan Caiyun and Lianghong Poplar seedlings treated with 200 mM NaCl for 4 weeks, the hydrogen peroxide and superoxide anion contents of Zhongshan Caiyun and Lianghong Poplar seedlings treated with 200 mM NaCl + 20 mL suspended bacteria were significantly reduced.

[0076] Table 4 H2O2 content

[0077] <![CDATA[H2O2content(μmol.g -1 FW)]]> Zhongshan Color Rhythm Beautiful red poplar 200mM NaCl 0.83 0.88 200mMNaCl+bacterial liquid 0.57 0.72

[0078] Table 5 H2O2 content

[0079] <![CDATA[O2 - content(umol.g -1 FW)]]> Zhongshan Color Rhythm Beautiful red poplar 200mM NaCl 42.5 46.8 200mMNaCl+bacterial liquid 36.4 40.8

[0080] In summary, the 20 mL suspended bacterial treatment can reduce the contents of hydrogen peroxide, superoxide anion, and MDA in Zhongshan Caiyun and Lianghong Yang seedlings after 200 mM NaCl treatment by increasing the activities of SOD, POD, and CAT enzymes, and further increase the proline concentration, chlorophyll content, and Fv.Fm in Zhongshan Caiyun and Lianghong Yang seedlings. -1Thereby, the external morphology of Zhongshan Caiyun and Lianghong Poplar seedlings such as plant height and root length will change, and the salt tolerance of Zhongshan Caiyun and Lianghong Poplar seedlings will be enhanced.

[0081] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. Application of Bacillus nitratirecucens Cdb8-1 in improving the salt-alkali tolerance of colorful poplar.

2. The use according to claim 1, characterized in that The colorful poplars include Zhongshan Caiyun and Lianghong Poplar.

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