Application of combined inoculation of rhizosphere phosphorus solubilizing bacteria in plant growth promotion and soil nutrient improvement

Abstract

The application discloses application of combined inoculation of rhizosphere phosphorus solubilizing bacteria in plant growth promotion and soil nutrient improvement, and belongs to the technical field of microorganisms.The combined inoculation of acinetobacter and pantoea provided by the application can effectively convert insoluble inorganic phosphorus into soluble inorganic phosphorus, and promotes the utilization of phosphorus.The combined inoculation of acinetobacter and pantoea has significant soil phosphorus solubilizing capacity and plant growth promotion effect when the ratio of acinetobacter to pantoea is (4-6):(6-4), and can be applied to improving soil phosphorus utilization rate and promoting plant growth, and has important agricultural and environmental values.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of microbial technology. It relates to the application of combined inoculation of rhizosphere phosphorus solubilizing bacteria in plant growth promotion and soil nutrient improvement, in particular to the application of combined inoculation of Acinetobacter sp. and Pantoea sp. in soil phosphorus solubilization and plant growth promotion. BACKGROUND

[0002] Phosphorus is one of the essential macroelements for plant growth and development. However, more than 90% of phosphorus in soil is in the form of ineffective phosphorus, which limits the absorption and utilization of phosphorus nutrients by plants. Phosphorus solubilizing bacteria can convert insoluble phosphorus in soil into available phosphates that can be absorbed by plants, improve the utilization rate of phosphorus in soil, and promote plant growth. Currently, the widely used phosphorus solubilizing bacterial fertilizer preparations on the market are mainly based on Bacillus sp., and the promotion effect of combined inoculation of multiple phosphorus solubilizing bacteria on soil and plant growth is not necessarily superior to single inoculation. This may be due to the antagonistic effect between multiple bacteria, which inhibits the activity of the bacteria when they are inoculated together, thereby reducing their growth-promoting efficiency. Therefore, research on the appropriate ratio of phosphorus solubilizing bacteria not only provides new strain resources for the development of bacterial fertilizer, but also has important application value. SUMMARY

[0003] A method for promoting plant growth, wherein a Pantoea cypripedii and an Acinetobacter sp. are added to a system for cultivating plants.

[0004] The Pantoea cypripedii has been deposited with the China General Microbiological Culture Collection Center on December 12, 2024, and the deposit number is CGMCC No. 33054.

[0005] The Acinetobacter sp. has been deposited with the China General Microbiological Culture Collection Center on December 12, 2024, and the deposit number is CGMCC No. 33053.

[0006] The method according to [1], wherein the Pantoea cypripedii and the Acinetobacter sp. are added in a ratio of (4-6):(6-4).

[0007] The method according to [2], wherein the total concentration of the Pantoea cypripedii and the Acinetobacter sp. is not less than 10 6 cfu / mL.

[0008] The method according to any one of [1] to [3], wherein the plant comprises tomato, wheat, rice, corn, cotton, oilseed rape, soybean, pea, preferably tomato.

[0009] The method according to any one of [1] to [4], wherein the promoting plant growth comprises at least one of promoting plant height, promoting stem girth, promoting aboveground fresh weight, and promoting underground fresh weight.

[0010] A method for improving soil nutrient conditions, wherein a strain of Pantoea cypripedii and Acinetobacter sp. are added to the soil.

[0011] The strain of Pantoea cypripedii has been deposited with the China General Microbiological Culture Collection Center on December 12, 2024, and has the accession number CGMCC No. 33054.

[0012] The Acinetobacter sp. has been deposited with the China General Microbiological Culture Collection Center on December 12, 2024, and has the accession number CGMCC No. 33053.

[0013] The method according to [6], wherein the strain of Pantoea cypripedii and Acinetobacter sp. are added in a ratio of (4-6):(6-4).

[0014] The method according to [6] or [7], wherein the total concentration of the strain of Pantoea cypripedii and Acinetobacter sp. is not less than 10 6 cfu / mL.

[0015] The method according to any one of [5] to [8], wherein the improving soil nutrient conditions comprises increasing the content of available potassium in the soil, increasing the content of available phosphorus in the soil, and increasing the content of organic matter in the soil.

[0016] Beneficial effects:

[0017] The present application has significant soil phosphorus solubilizing ability and plant growth promoting effect by inoculating the Acinetobacter sp. and the strain of Pantoea cypripedii in a ratio between (4-6):(6-4), which can be applied to improve soil phosphorus utilization and promote plant growth, and has important agricultural and environmental value.

[0018] Biological material preservation

[0019] The phosphorus solubilizing bacteria PoPSB-1 provided in the present application is classified as Acinetobacter sp., and has been preserved in the China General Microbiological Culture Collection Center on December 12, 2024, with a preservation number of CGMCC No. 33053 and a preservation address of No. 3, Yitianxili, Beichen, Chaoyang District, Beijing, Institute of Microbiology, Chinese Academy of Sciences.

[0020] The phosphorus solubilizing bacteria PoPSB-2 provided in the present application is classified as Pantoea cypripedii, and has been preserved in the China General Microbiological Culture Collection Center on December 12, 2024, with a preservation number of CGMCC No. 33054 and a preservation address of No. 3, Yitianxili, Beichen, Chaoyang District, Beijing, Institute of Microbiology, Chinese Academy of Sciences. BRIEF DESCRIPTION OF DRAWINGS

[0021] Figure 1 The growth status of tomato seedlings in Example 1 is shown. DETAILED DESCRIPTION

[0022] The inventors previously screened two strains of phosphorus solubilizing bacteria with good phosphorus solubilizing effect from the rhizosphere soil of peony ‘Fengdan’, which can convert insoluble phosphorus into soluble phosphorus, and are PoPSB-1 and PoPSB-2. Among them, PoPSB-1 is Acinetobacter, and PoPSB-2 is a Pantoea strain.

[0023] Tomato is a plant that relies on soluble phosphorus for growth and development. Soluble phosphorus is a key factor for tomato plants to carry out biological processes such as photosynthesis, energy metabolism, and signal transduction. Soluble phosphorus in the soil can be absorbed by the tomato root system and converted into phosphorus compounds required by the plant, promoting fruit formation and maturation. However, usually, most of the phosphorus in the soil exists in a form that is difficult to be utilized by tomato, so the inventors tried to add the screened phosphorus solubilizing strains PoPSB-1 and PoPSB-2 to the soil in which tomato is cultivated, and different combinations of the two were made, and unexpectedly the best ratio was found, which can effectively promote the growth of tomato, and also has a significant improvement effect on soil nutrients (for example, it can promote the content of available potassium, available phosphorus, and organic matter in the soil).

[0024] In this paper, “available potassium” refers to potassium in the soil that is easily absorbed and utilized by crops, including soil solution potassium and soil exchangeable potassium. Available potassium accounts for 0.1% to 2% of the total potassium in the soil, of which soil solution potassium accounts for 1% to 2% of available potassium. Because the proportion is very low, it is often included in exchangeable potassium. The content of available potassium is one of the important indicators for characterizing the supply status of soil potassium.

[0025] In this paper, "available phosphorus", also known as available phosphorus, is the component of phosphorus in soil that can be absorbed by plants. It includes all water-soluble phosphorus, part of the adsorbed phosphorus and organic phosphorus, and some precipitated phosphorus in some soils.

[0026] In this paper, "organic matter" refers to the life-derived substances in the soil, including soil microorganisms and soil animals and their secretions, as well as plant residues and plant secretions in the soil.

[0027] Example 1

[0028] The previously screened phosphorus-solubilizing bacterial strains PoPSB-1 and PoPSB-2 were inoculated into 40 mL of LB liquid medium, cultured overnight at 180 r / min and 30°C, and then centrifuged after 18 h to collect the bacterial solution. The bacterial solution was washed twice with 40 mL of sterile water, and finally adjusted to a concentration of 10 6 cfu / mL.

[0029] Prepare bacterial suspensions with different proportions:

[0030] PoPSB-1:PoPSB-2=4:6, i.e. the concentration of PoPSB-1 is 4×10 5 cfu / mL, and the concentration of PoPSB-2 is 6×10 5 cfu / mL;

[0031] PoPSB-1:PoPSB-2=6:4, i.e. the concentration of PoPSB-1 is 6×10 5 cfu / mL, and the concentration of PoPSB-2 is 4×10 5 cfu / mL;

[0032] PoPSB-1:PoPSB-2=2:8, i.e. the concentration of PoPSB-1 is 2×10 5 cfu / mL, and the concentration of PoPSB-2 is 8×10 5 cfu / mL;

[0033] PoPSB-1:PoPSB-2=8:2, i.e. the concentration of PoPSB-1 is 8×10 5 cfu / mL, and the concentration of PoPSB-2 is 2×10 5 cfu / mL.

[0034] Each pot was filled with 1.0 kg of test soil, and 30 tomato seedlings with basically uniform growth were selected and planted in it.

[0035] The treatment group was added with 40 mL of the bacterial suspension with different proportions (PoPSB-1:PoPSB-2=4:6 or 6:4 or 2:8 or 8:2) described above, and 40 mL of sterile water was used as a control. The treatment group and the control group were both set with 6 repetitions, and the root irrigation method was used when inoculating, and then the tomato seedlings were placed in an artificial climate incubator for cultivation. After 25 days, the growth indexes of the tomato seedlings and the soil nutrient content were determined.

[0036] The growth of the tomato seedlings was as shown in Figure 1

[0037] Table 1. Tomato growth indexes:

[0038]

[0039] Table 2. Soil nutrient content:

[0040]

[0041] Although the present application has been disclosed in the above preferred embodiments, it is not intended to limit the present application, and any person skilled in the art can make various modifications and modifications without departing from the spirit and scope of the present application, and therefore the protection scope of the present application should be defined by the claims.​

Claims

1. A method for promoting tomato growth, characterized in that: Pantoea cypripedii and Acinetobacter sp. were added to the tomato culture system; The Pantoea strain Pantoea cypripedii was deposited in the General Microbiology Center of the China Culture Collection Administration of Microorganisms on December 12, 2024, with the deposit number CGMCC No. 33054; The Acinetobacter sp. was deposited in the General Microbiology Center of China Culture Collection Administration of Microorganisms on December 12, 2024, with the deposit number CGMCC No. 33053; The Pantoea cypripedii strain and Acinetobacter sp. are added in a ratio of (4-6): (6-4).

2. The method according to claim 1, characterized in that The total concentration of Pantoea cypripedii and Acinetobacter sp. is not less than 10 6 cfu / mL.

3. The method according to any one of claims 1 or 2, characterized in that The promoting of tomato growth includes at least one of promoting plant height, promoting stem circumference, increasing the fresh weight of aboveground parts and increasing the fresh weight of underground parts.

4. A method for improving soil nutrient status, characterized in that: Pantoeacypripedii and Acinetobacter sp. were added to the soil; The Pantoea strain Pantoea cypripedii was deposited in the General Microbiology Center of the China Culture Collection Administration of Microorganisms on December 12, 2024, with the deposit number CGMCC No. 33054; The Acinetobacter sp. was deposited in the General Microbiology Center of China Culture Collection Administration of Microorganisms on December 12, 2024, with the deposit number CGMCC No. 33053; The Pantoea cypripedii strain and Acinetobacter sp. are added in a ratio of (4-6): (6-4).

5. The method according to claim 4, characterized in that The total concentration of Pantoea cypripedii and Acinetobacter sp. is not less than 10 6 cfu / mL.

6. The method according to any one of claims 4 or 5, characterized in that The improvement of soil nutrient status includes: increasing the content of available potassium in the soil, increasing the content of available phosphorus in the soil, and increasing the content of organic matter in the soil.

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