Application of Pseudomonas aeruginosa SDF-LT

Abstract

The present invention relates to the field of industrial microbial technology, and specifically discloses the application of Pseudomonas sp. SDF-LT with a deposit number of CGMCC No. 40106 in promoting wheat growth. The microbial agent prepared by compounding Penicillium breviscompactum with Pseudomonas sp. SDF-LT can not only promote the rapid decomposition of straw in a low temperature range of 4 to 10°C, increase the content of total nitrogen, total potassium, alkaline nitrogen and available potassium in the soil, but also has an excellent effect of promoting the growth and development of wheat, can effectively increase the emergence rate of wheat seedlings, promote the development of wheat root system and dry matter accumulation, and at the same time, it also has the effect of improving the rhizosphere soil environment and increasing the activity of urease in the soil, thereby promoting the full utilization of nitrogen in the soil by wheat and promoting wheat growth, and has a high practical value.

Description

Technical Field

[0001] The invention relates to the technical field of industrial microorganisms, and in particular to a new application of Pseudomonas sp. SDF-LT. Background Art

[0002] Wheat is the world's largest crop with the largest planting area, the highest yield and the widest distribution. The yield and quality of wheat are directly related to the food security of various countries. In northern my country, wheat-corn rotation is generally adopted, corn straw is directly returned to the field, and continuous cropping and unreasonable fertilization technology, especially the wheat production model based on the application of chemical fertilizers, have led to a decline in soil health and a decrease in wheat yield and quality year by year. Microbial agents are preparations made from beneficial microbial flora with special functions. They improve soil structure, increase soil fertility, and improve soil microbial diversity through the life activities of the microorganisms themselves, and can reduce the use of chemical fertilizers and pesticides. At the same time, they also have the effect of improving yield and quality. Therefore, the current application of microbial agents that promote growth and regulate the soil microecological environment is the main measure to reduce the use of chemical fertilizers and restore soil health.

[0003] Most of the current microbial agents promote wheat growth by promoting wheat's utilization of nitrogen, phosphorus and potassium in the soil, and have a single function. For the wheat rotation production model in the north where straw is directly returned to the field, due to the slow degradation of straw, the nutrients cannot be fully utilized by wheat, affecting the germination rate of crops, and it is also easy to become a carrier of crop diseases and insect pests, resulting in a reduction in wheat production. Therefore, the application of current conventional microbial agents has no obvious effect on improving wheat yield and quality. However, the current straw composting agents generally do not have the effect of promoting wheat growth. The simultaneous application of straw composting agents and microbial agents that promote wheat growth will lead to a significant increase in wheat production costs. Therefore, it is urgent to find a microbial agent that can not only quickly corrode straw but also promote wheat growth, which is of great significance to increasing wheat yield and increasing the income of wheat growers. Summary of the invention

[0004] In view of the problems that existing microbial agents have limited effect on promoting wheat growth in the northern crop rotation pattern, and that straw composting agents have no effect on promoting wheat growth, the present invention provides a new application of Pseudomonas sp. SDF-LT.

[0005] In order to solve the above technical problems, the technical solution provided by the present invention is:

[0006] The application of Pseudomonas aeruginosa SDF-LT with the deposit number of CGMCC No.40106 in promoting wheat growth.

[0007] Pseudogymnoascus SDF-LT was screened out from the wheat topsoil in Leting County, Tangshan City, Hebei Province using the sodium cellulose-Congo red solid culture medium method. It was classified and named Pseudogymnoascus sp. and was deposited in the General Microbiology Center of the China Culture Collection of Microorganisms, abbreviated as CGMCC, on February 22, 2022. The strain collection number is CGMCC No. 40106, and the storage address is: Institute of Microbiology, Chinese Academy of Sciences, No. 3, Yard 1, Beichen West Road, Chaoyang District, Beijing.

[0008] The biological characteristics of the pseudogymna SDF-LT provided by the present invention are as follows: at 10° C., on a PDA solid culture medium, the initial colonies are white, nearly round colonies, and feathery, and a large number of rusty red granules are generated on the surface of the colonies in the later stage. Under an optical microscope, the conidiophores of the fungus are observed to be various short branches, translucent, smooth and upright, and the conidia are directly formed from the ends of the conidiophores and are elliptical.

[0009] For wheat grown under the condition of returning straw to the field, the microorganisms in the straw will compete with the wheat seedlings for nutrients, affecting their normal growth. In addition, the wheat fields where straw is returned to the field are relatively loose, with large and uneven pores, and the wheat seeds cannot stick to the soil, resulting in unstable wheat roots and affecting the wheat germination rate.

[0010] The pseudogymna SDF-LT provided by the present invention can not only promote the rapid decomposition of straw in a low temperature range of 4 to 10°C, and increase the contents of total nitrogen, total potassium, alkaline-hydrolyzed nitrogen and available potassium in the soil, but also has an excellent effect of promoting the growth and development of wheat, can effectively improve the emergence rate of wheat seedlings, promote the development of wheat root system and dry matter accumulation, and at the same time, has the effect of improving the rhizosphere soil environment and increasing the urease activity in the soil, thereby promoting the full utilization of nitrogen in the soil by wheat and promoting the growth of wheat, and has high practical value.

[0011] The invention also provides the use of Pseudomonas sp. SDF-LT with a deposit number of CGMCC No. 40106 in preparing a microbial agent for promoting wheat growth.

[0012] The present invention also provides a microbial agent for promoting wheat growth, comprising Pseudomonas aeruginosa SDF-LT with a preservation number of CGMCC No.40106.

[0013] The pseudogymna SDF-LT provided by the present invention can not only be widely used in straw degradation in various regions of China, but also has an excellent effect of promoting the growth and development of wheat. It can be made into a microbial agent for convenient use and has a very high value for promotion and application.

[0014] Preferably, the microbial agent for promoting wheat growth also includes Penicillium breviscompactum.

[0015] In the present invention, the combination of Penicillium breviscompactum and Pseudomonas sp. SDF-LT can not only realize effective straw decomposition at low temperature, but also promote the growth and development of wheat, improve the disease resistance of wheat, and improve the yield and quality of wheat.

[0016] Preferably, the ratio of the viable counts of Pseudomonas sp. SDF-LT to Penicillium breviscompactum is 1-2:1-2.

[0017] Preferably, the viable count of Pseudomonas sp. SDF-LT in the microbial agent is 2×10 7 ~7×10 8 Pieces / mL.

[0018] The preferred ratio of Pseudogycetes to Penicillium breviscompactum, as well as the number of live Pseudogycetes, can effectively reduce production costs while ensuring that the microbial agent has a high ability to degrade straw and promote wheat growth.

[0019] The present invention also provides a method for preparing the liquid microbial agent, comprising the following steps:

[0020] Step a, inoculating the pseudogymna SDF-LT into a PD liquid culture medium, culturing at 10°C to 20°C and 180r / min to 200r / min for 5 to 6 days, inoculating the cultured bacterial solution into a PDA solid culture medium, culturing at 10°C to 20°C for 120h to 130h, and then washing the spores on the PDA solid culture medium with sterile distilled water to make the number of viable bacteria in the obtained microbial bacterial solution ≥ 2×10 7 / mL, and obtain Pseudomonas aeruginosa SDF-LT bacterial solution;

[0021] Step b, inoculating the short compact Penicillium into the PD culture medium, culturing at 10°C to 20°C and 180r / min to 200r / min for 5 to 6 days, inoculating the cultured bacterial solution into the PDA culture medium, culturing at 10°C to 20°C for 120h to 130h, and then washing the spores on the PDA solid culture medium with sterile distilled water to make the number of viable bacteria in the obtained microbial bacterial solution ≥ 2×10 7 / mL, and obtain the bacterial solution of Penicillium breve;

[0022] Step c, mixing the bacterial solution of Pseudomonas sp. SDF-LT and the bacterial solution of Penicillium breviscompactum evenly to obtain a microbial agent for promoting wheat growth.

[0023] Preferably, the PD culture medium comprises: 200 g potato, 20 g glucose, 3 mL gentamicin sulfate injection and 1000 mL water, and is sterilized at 121° C. for 20 min.

[0024] Preferably, the PDA culture medium comprises: 200 g potato, 20 g glucose, 15 g agar, 3 mL gentamicin sulfate injection and 1000 mL water, and is sterilized at 121° C. for 20 min.

[0025] Exemplarily, the inoculation volume of the Pseudomonas sp. SDF-LT accounts for 5% of the volume of the PD liquid culture medium.

[0026] Exemplarily, the inoculation volume of Penicillium breviscompactum accounts for 5% of the volume of the PD liquid culture medium.

[0027] The pseudogymna SDF-LT provided by the present invention has excellent straw decomposition ability, and can quickly decompose straw even in a cold winter environment, and has a good effect of promoting the growth and development of wheat. It is compounded with Penicillium breviscompactum to prepare a microbial agent, which can effectively increase wheat yield and improve wheat quality, and has broad application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 This is a root system scan of the blank group in Application Example 1 of the present invention;

[0029] Figure 2 This is a root system scan of the SDF-LT bacterial solution group of Pseudomonas aeruginosa in Application Example 1 of the present invention;

[0030] Figure 3 This is a root system scan of the Penicillium breviscompactum bacterial solution group in Application Example 1 of the present invention;

[0031] Figure 4 This is a root system scan of the embodiment group in Application Example 1 of the present invention;

[0032] Figure 5 This is a root system scan of the control group in Application Example 1 of the present invention;

[0033] Figure 6 This is a root system scan of Comparative Example 1 in Application Example 1 of the present invention;

[0034] Figure 7 This is a root system scan of Comparative Example 2 in Application Example 1 of the present invention. DETAILED DESCRIPTION

[0035] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0036] The culture medium used in the examples is:

[0037] PDA medium (1L): 200g potato, 20g glucose, 15g agar, 3mL gentamicin sulfate injection, 1000mL water, natural pH, sterilize at 121℃ for 20min before use.

[0038] PD liquid culture medium (1L): 200g potato, 20g glucose, 3mL gentamicin sulfate injection, 1000mL water, natural pH, sterilize at 121℃ for 20min before use.

[0039] Sodium cellulose-Congo red medium: sodium carboxymethyl cellulose 5g, (NH4)2SO4 2g, KH2PO41g, MgSO4·7H2O 0.5g, NaCl 0.5g, NaNO3 1g, peptone 0.5g, yeast extract 0.5g, Congo red 0.2g, agar 12g, water 1000mL, pH 7.0, 121℃, high pressure sterilization for 20min before use.

[0040] Straw liquid culture medium: Use a 100mL triangular flask, put 2g of 1cm long corn straw and 30mL of nutrient solution in the bottle. Nutrient solution formula:

[0041] Urea 3.0g, (NH4)2SO4 6.0g, peptone 3.0g, CaCl2 0.1g, MgSO4·7H2O0.5g, K2HPO41.0g, NaCl 0.1g, FeSO4·7H2O 0.05g, MnSO4·7H2O 0.016g, ZnSO4·7H2O 0.014g, CoCl2·6H2O 0.037g, distilled water 1000mL, natural pH, sterilize at 121℃ for 30min before use.

[0042] Commercially available straw composting agents: The straw composting agent produced by Luoyang Ouke Biotechnology Co., Ltd. has an effective live bacteria count of >500 million / g. The effective bacteria are Bacillus subtilis and Trichoderma harzianum. It contains complex bacteria such as lactic acid bacteria and yeast, and the dosage form is powder.

[0043] Example 1

[0044] 1. Initial screening of Pseudogycetes

[0045] Samples were collected from wheat plough soil in Leting County, Tangshan City. The strains were separated using PDA medium by dilution plating method. A total of 100 strains with different colony morphologies were obtained. The isolated bacteria were streaked and purified multiple times to obtain pure culture strains and preserve them. The 42 purified strains were inoculated on sodium cellulose-Congo red medium and cultured at 10°C. The colony diameter (d) and transparent circle diameter (D) were measured after 5 days of culture, and the D / d value was calculated.

[0046] The Pseudogycetes SDF-LT with the deposit number CGMCC No.40106 can grow on sodium carboxymethylcellulose-Congo red medium and produce a transparent hydrolysis zone with a diameter of more than 3.5 cm. The D / d value is 2.6 at 10°C, indicating that the fungus has a high straw degradation ability and good low temperature adaptability.

[0047] 2. Rescreening of Pseudogycetes

[0048] The strains with straw degradation ability obtained in the initial screening were inoculated into PDA medium and cultured in a shaking incubator at 10°C for 72 h. Then 1 mL of the bacterial solution was aspirated and inoculated into the straw medium respectively. The medium was placed in an incubator at 10°C for culture and shaken twice a day. At 7 and 15 days of culture, the straw in the bottle was rinsed 3 times with distilled water and dried to constant weight. The weight of the corn straw in each treatment was weighed and the degradation rate was calculated. Each treatment was repeated 3 times.

[0049] Straw degradation rate (%) = (W0-W1) / W0×100%

[0050] W0 is the weight of the straw in the culture medium before inoculation; W1 is the weight of the straw after drying after the culture is completed.

[0051] When the pseudogymna SDF-LT with the deposit number CGMCC No.16280 was cultured at 10℃, the straw degradation rates were 13.99% and 30.04% after 7 and 15 days of culture, respectively.

[0052] Morphological observation

[0053] The biological characteristics of Pseudogycetes SDF-LT are as follows: at 10℃, on PDA solid medium, the initial colonies are white, nearly round colonies, and feathery, and a large number of rusty red granules are generated on the surface of the colonies in the later stage. Under an optical microscope, the conidiophores of the fungus are short branches of various shapes, translucent, smooth and upright, and the conidia are formed directly from the ends of the conidiophores and are oval. According to the colony morphology and conidia structure characteristics, the strain SDF-LT can be preliminarily determined to be a Pseudogycetes genus by comparing and analyzing with the Manual of Fungal Identification and the Chinese Mycology.

[0054] Molecular Biology Identification

[0055] The fungal genomic DNA extraction kit (Beijing Solebow Technology Co., Ltd.) was used to extract the genomic DNA of the strain SDF-LT as a PCR amplification template, and the fungal universal primers ITS1 (5'-TCCGTAGGTGAACCTGCGG-3') and ITS4 (5'-TCCTCCGCTTATTGATATGC-3') were used to amplify the ITS region rDNA sequence of the strain. The ITS sequence was amplified according to the reaction conditions (94℃5min, 94℃1min, 53℃1min, 72℃1min, 33 cycles, 72℃7min) to obtain a 559bp amplification product, which was sequenced. The ITS sequence of the strain is sequence 3 in the sequence table. The determined sequences were compared and analyzed by BLAST in the database of the National Center of Biotechnology (NCBI), and finally a phylogenetic tree was constructed with the help of the Neighbor-Joining method of MEGA 5.1 (such as Figure 5 The phylogenetic status of the strain was determined, and combined with the morphological characteristics of the strain, it was determined that the strain was Pseudogymnoascus sp. SDF-LT.

[0056] The strain SDF-LT was deposited in the General Microbiology Center of the China Microorganism Culture Collection Administration, abbreviated as CGMCC, on February 22, 2022. The strain deposit number is CGMCC No.40106, and the deposit address is: Institute of Microbiology, Chinese Academy of Sciences, No. 3, No. 1 Beichen West Road, Chaoyang District, Beijing.

[0057] Example 2

[0058] This embodiment provides a microbial agent for promoting wheat growth, and the preparation method thereof comprises the following steps:

[0059] The pseudogymna SDF-LT with the collection number of CGMCC No.16280 stored at -80℃ was inoculated into PD liquid medium and cultured at 10℃ and 180r / min for 5 days. Then, 200μL of the cultured bacterial solution was inoculated into PDA solid medium and cultured at 10℃ for 120h. Then, the spores on the PDA solid medium were washed off with sterile distilled water and counted by blood cell plate. The number of viable bacteria in the obtained microbial bacterial solution was 2×10 7 Pieces / mL;

[0060] Step b, inoculating the short compact Penicillium into the PD culture medium, culturing at 10°C to 20°C and 180r / min to 200r / min for 5 to 6 days, inoculating the cultured bacterial solution into the PDA culture medium, culturing at 10°C to 20°C for 120h to 130h, and then washing the spores on the PDA solid culture medium with sterile distilled water to make the number of viable bacteria in the obtained microbial bacterial solution 2×10 7 / mL, and obtain the bacterial solution of Penicillium breve;

[0061] Step c, the bacterial solution of Pseudomonas sp. SDF-LT and the bacterial solution of Penicillium breviscompactum are mixed evenly in a volume ratio of 1:1 to obtain a microbial agent for promoting wheat growth, and the number of viable bacteria is detected to be 4×10 7 Pieces / mL.

[0062] Comparative Example 1

[0063] This comparative example provides a microbial agent, the composition and preparation method of which are different from those of Example 3 only in that Penicillium breviscompactum is replaced by Penicillium aureum.

[0064] Comparative Example 2

[0065] This comparative example provides a microbial agent, the composition and preparation method of which are different from those of Example 3 only in that Pseudomonas aeruginosa SDF-LT is replaced by JG9-31 (with a deposit number of CGMCC No. 16280).

[0066] Application Example 1

[0067] Wheat was planted in a potted plant method. A square flower pot with a diameter of 10 cm and a height of 10 cm was used. 1.5 g of crushed corn stalks was mixed with 500 g of soil and placed in the square flower pot. The viable bacteria prepared in Example 2 were 4 × 10 7 3mL of microbial agent of 1000 g / mL was added, and the soil moisture was adjusted to about 60%. Seven test groups were set up: blank group, control group, pseudogymna SDF-LT bacterial liquid group, short compact Penicillium bacterial liquid group, comparative example 1 group, comparative example 2 group and test group, each test group was set up with 3 parallels, each parallel sample had 10 flower pots, each flower pot was planted with 9 wheat seeds, and then each treatment flower pot was placed at 22°C room temperature for cultivation. 3 mL of the microbial agent prepared in Example 2 was used as the example group, 200 g / mu of commercially available straw decomposing agent + 3 mL of the short-compacted Penicillium solution in Example 2 was used as the control group, 3 mL of the microbial agent prepared in Comparative Example 1 was used as Comparative Example 1 group, 3 mL of the microbial agent prepared in Comparative Example 2 was used as Comparative Example 2 group, 3 mL of the Pseudomonas SDF-LT bacterial solution prepared in Example 2 was used as the Pseudomonas SDF-LT bacterial solution group, 3 mL of the short-compacted Penicillium solution prepared in Example 2 was used as the short-compacted Penicillium solution group, and the group without adding bacterial agent was used as the blank group.

[0068] After 7 days, the germination rate of wheat was measured (referring to the percentage of the number of germinated grains in the conventional germination test in 7 days to the total number of test grains), and the plant height, fresh weight and dry weight of the aboveground part of wheat were measured after 28 days. Forty samples of wheat were randomly selected from each treatment, and their stem fresh weight (g) was measured; the aboveground part of the plant was dried at 80℃ to constant weight and its dry weight (g) was measured; the distance from the base of the stem to the top of the stem was taken as the plant height (cm). The results are shown in Table 1.

[0069] Table 1

[0070]

[0071] Note: Different letters indicate significant differences between the two groups at P < 0.05.

[0072] As can be seen from Table 1, the emergence rate, plant height, fresh weight and dry weight of wheat in the embodiment group are higher than those in the control group, comparative example 1-2 group and blank group, and there are significant differences compared with the blank group and the control group. The emergence rate of wheat in the embodiment group is increased by 3% and 6% compared with comparative example 1-2, respectively, and there is a significant difference from comparative example 2. The dry weight of wheat in the embodiment group is the highest, which is increased by 14.5% and 17.0% compared with comparative examples 1-2, respectively.

[0073] Soil physical and chemical properties: wheat pot soil was taken, naturally air-dried, ground and sieved, and soil organic matter, total nitrogen, alkaline nitrogen, available phosphorus, available potassium and soil urease were determined. Among them, the soil organic matter was determined by potassium dichromate volumetric method, the total nitrogen was determined by potassium permanganate method, the alkaline nitrogen was determined by indirect diffusion method, the available phosphorus was determined by sodium bicarbonate extraction-molybdenum antimony colorimetric method, the available potassium was determined by ammonium acetate extraction-flame photometry, and the soil urease activity was determined by soil urease detection kit, Nanjing Jiancheng Bioengineering Research Institute, item number: A121-1-1. The results are shown in Table 2.

[0074] Table 2

[0075]

[0076]

[0077] Note: Different letters indicate significant differences between the two groups at P < 0.05.

[0078] As can be seen from Table 2, the soil organic matter, available phosphorus, quick-acting potassium, and alkaline-hydrolyzed nitrogen contents of the embodiment group are higher than those of the control group, comparative example 1-2 groups, and the blank group. The organic matter content of the embodiment group is significantly higher than that of the control group and comparative example 1 group. Compared with comparative example 2 group, the organic matter content of the embodiment group increased by 3.89%; the effective phosphorus content of the embodiment group was significantly higher than that of the control group; compared with comparative example 1 group and comparative example 2 group, the effective phosphorus content increased by 7.49% and 5.16%, respectively; the quick-acting potassium, alkaline-hydrolyzed nitrogen content, and urease activity of the embodiment group were significantly different from those of the control group.

[0079] After 28 days of the above experiment, the wheat roots were separated and scanned with an EPSON scanner. The root indexes were analyzed with a WinRHIZO PRO2013 plant root analysis system (Regent, Canada), mainly focusing on the total root length and total root surface area. Figure 1 As shown, the root system scan of the Pseudomonas SDF-LT bacterial solution group is as follows Figure 2 As shown, the root system scan of the Penicillium breve liquid group is as follows Figure 3 As shown, the root system scanning diagram of the embodiment group is as follows Figure 4 The root scan of the control group is shown in Figure 5 As shown, the root system scanning diagram of the comparative example 1 group is as follows Figure 6 As shown, the root system scanning diagram of the comparative example 2 group is as follows Figure 7 shown.

[0080] It can be seen from the figure that the wheat roots of the Pseudomonas SDF-LT bacterial solution group, the Penicillium breviscapus bacterial solution group and the embodiment group are large and strong. According to software analysis, the total root length of wheat in the blank group is 107cm and the total surface area is 4.05cm 2 The total root length of wheat in the Pseudomonas sp. SDF-LT bacterial solution group was 325 cm, and the total surface area was 21.95 cm 2 The total root length of wheat in the Penicillium breviscapus group was 329 cm, and the total surface area was 24.32 cm 2 The total root length of wheat in the embodiment group was 351 cm, and the total surface area was 28.76 cm 2 The total root length of wheat in the control group was 315 cm and the total surface area was 20.74 cm 2 The total root length of wheat in Comparative Example 1 was 334 cm and the total surface area was 20.49 cm 2 The total root length of wheat in Comparative Example 2 was 338 cm and the total surface area was 22.39 cm 2 It can be seen that the embodiment group of the present invention can effectively promote the development of wheat root system, and the effect is significantly better than that of the control group and the comparative example 1-2 group.

[0081] In summary, the microbial agent containing Pseudomonas aeruginosa SDF-LT and Penicillium breviscompactum provided by the present invention can significantly promote wheat growth, effectively increase soil fertility, promote wheat root development, and has high practical value.

[0082] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modification, equivalent substitution or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. Application of SDF-LT of Pseudogymnoascus sp. with a deposit number of CGMCC No.40106 in promoting wheat growth.

2. Application of Pseudomonas aeruginosa SDF-LT with a deposit number of CGMCC No.40106 in the preparation of a microbial agent for promoting wheat growth.

3. A microbial agent for promoting wheat growth, characterized in that: The invention comprises Pseudomonas aeruginosa SDF-LT and Penicillium breviscompactum with the deposit number of CGMCC No.40106.

4. The microbial agent for promoting wheat growth according to claim 3, characterized in that: The ratio of the live bacteria count of the pseudogymna SDF-LT to that of the breve-compact Penicillium is 1-2:1-2.

5. The microbial agent for promoting wheat growth according to claim 4, characterized in that: The number of live bacteria of Pseudomonas sp. SDF-LT in the microbial agent was 2×10 7 ~7×10 8 Pieces / mL.

6. The method for preparing the microbial agent for promoting wheat growth according to any one of claims 3 to 5, characterized in that: The steps include: Step a, inoculating the pseudogymna SDF-LT into a PD liquid culture medium, culturing at 10°C to 20°C and 180r / min to 200r / min for 5 to 6 days, inoculating the cultured bacterial solution into a PDA solid culture medium, culturing at 10°C to 20°C for 120h to 130h, and then washing the spores on the PDA solid culture medium with sterile distilled water to make the number of viable bacteria in the obtained microbial bacterial solution ≥ 2×10 7 / mL, and obtain Pseudomonas aeruginosa SDF-LT bacterial solution; Step b, inoculating the Penicillium breviscompactum into a PD culture medium, culturing at 10°C to 20°C and 180r / min to 200r / min for 5 to 6 days, inoculating the cultured bacterial solution into a PDA culture medium, culturing at 10°C to 20°C for 120h to 130h, and then washing the spores on the PDA solid culture medium with sterile distilled water to make the number of viable bacteria in the obtained microbial bacterial solution ≥ 2×10 7 / mL, and obtain the bacterial solution of Penicillium breve; Step c, mixing the bacterial solution of Pseudomonas sp. SDF-LT and the bacterial solution of Penicillium breviscompactum evenly to obtain a microbial agent for promoting wheat growth.

7. The method for preparing the microbial agent for promoting wheat growth according to claim 6, characterized in that: The PD culture medium includes: 200 g potato, 20 g glucose, 3 mL gentamicin sulfate injection and 1000 mL water, and is sterilized at 121° C. for 20 min.

8. The method for preparing the microbial agent for promoting wheat growth according to claim 6, characterized in that: The PDA culture medium comprises: 200 g of potato, 20 g of glucose, 15 g of agar, 3 mL of gentamicin sulfate injection and 1000 mL of water, and is sterilized at 121° C. for 20 min.

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