Pseudomonas capable of inhibiting pathogens of various plants and promoting the growth of various crops, screening method and application thereof

Abstract

The present invention provides a Pseudomonas that can inhibit pathogens of various plants and promote the growth of various crops, as well as a screening method and application. The Pseudomonas is Pseudomonas sp. A34-9, which has been deposited in the China Center for Type Culture Collection, with a deposit number of CCTCC NO: M 2022397 and a deposit date of April 8, 2022. The Pseudomonas has an inhibitory effect on various Fusarium, Phytophthora, and Rhizoctonia solani, among which the control effect on Fusarium solani is 59.69% and the control effect on Phytophthora is 75%. The Pseudomonas can inhibit the growth of various plant pathogenic fungi, and can also promote the increase of the yield of Salvia miltiorrhiza, Chinese yam, Atractylodes macrocephala, honeysuckle, wheat and peanuts.

Description

Technical Field

[0001] The invention relates to a pseudomonas capable of inhibiting pathogenic bacteria of various plants and promoting the growth of various crops, a screening method and application thereof, and belongs to the technical field of microorganisms. Background Art

[0002] With the requirements of the sustainable development strategy of modern agriculture, biological control methods not only meet this strategic goal, but also can effectively promote the development of the agricultural industry. At present, biological control has received widespread attention in the control of soil-borne diseases. Root rot, wilt, and black leg are common soil-borne diseases. Various Fusarium, Rhizoctonia solani, and Phytophthora are the main pathogens causing root rot, wilt, damping-off, black leg and other diseases of various crops. While controlling the occurrence of diseases and recovering crop yield and quality losses, the role of biocontrol bacteria in promoting crop growth has also received widespread attention. Using biocontrol bacteria to replace the use of chemical pesticides and fertilizers has gradually become a research hotspot in modern agricultural technology. Biocontrol bacteria that promote crop production and control the occurrence of diseases can promote plant growth and development by solubilizing phosphorus, potassium and nitrogen, and producing plant growth hormones such as indoleacetic acid IAA. In recent years, there have been few reports on bacteria that have a growth-promoting effect on a variety of crops and produce IAA. Therefore, screening strains that can produce IAA and promote crop growth has important theoretical and practical significance. Summary of the invention

[0003] In view of the shortcomings of the prior art, the present invention aims to provide a Pseudomonas that can inhibit the pathogens of various plants and promote the growth of various crops, as well as a screening method and application. The Pseudomonas can inhibit the growth of various plant pathogenic fungi and promote the yield of salvia miltiorrhiza, yam, atractylodes macrocephala, honeysuckle, wheat and peanuts.

[0004] In order to achieve the above object, the technical solution adopted by the present invention is:

[0005] A pseudomonas capable of inhibiting plant pathogens and having a growth-promoting effect, wherein the pseudomonas is Pseudomonas sp. A34-9, which has been deposited in the China Center for Type Culture Collection, with a deposit number of CCTCC NO: M2022397 and a deposit date of April 8, 2022.

[0006] The plant pathogens include: Fusarium, Rhizoctonia solani, and Phytophthora.

[0007] The Fusarium includes: Fusarium asiatica, Fusarium equisetum, Fusarium graminearum, Fusarium pseudograminearum, Fusarium solani, Fusarium oxysporum.

[0008] Plants that inhibit plant pathogens and have growth-promoting effects include: Salvia miltiorrhiza, yam, Atractylodes macrocephala, honeysuckle, wheat, and peanut.

[0009] The screening method for Pseudomonas comprises collecting rhizosphere soil of tobacco planted in Arshan, Inner Mongolia, adding the soil to sterile water and fully shaking it to obtain a soil suspension, then diluting the soil suspension in multiple ratios, applying the dilution on a KB solid culture medium, and inverting and culturing it in a constant temperature incubator at 28°C for 36 hours until colonies grow, separating and purifying them, and screening out strains.

[0010] The method for preparing a fermentation liquid when the pseudomonads are used to promote plant growth comprises the following steps: inoculating the pseudomonads A34-9 in a KB culture medium, oscillating and culturing at 28°C and 180rpm for 16h to prepare a seed bacterium; inoculating the seed bacterium in a KB culture medium at an inoculum amount of 3% (v / v), fermenting at 28°C and 180rpm for 48h to form a fermentation liquid; the concentration of live pseudomonads in the fermentation liquid is 10 9 ~10 10 CFU / mL.

[0011] KB culture medium includes: 20 g of peptone, 10 mL of glycerol, 1.5 g of dipotassium hydrogen phosphate, 1.5 g of magnesium sulfate heptahydrate, 0 g or 20 g of agar, add distilled water to make up to 1000 mL, mix well and dispense into Erlenmeyer flasks, and sterilize at 121°C for 30 min.

[0012] The application of the Pseudomonas in inhibiting plant pathogens.

[0013] The application of the Pseudomonas in promoting plant growth.

[0014] The pseudomonad is used in preventing and controlling soil-borne root diseases of crops.

[0015] Beneficial effects of the present invention:

[0016] The present invention screened out the biocontrol bacteria P34-9 which can simultaneously prevent and control multiple soil-borne fungal diseases and increase crop yield from the soil of Arshan Mountain for the first time through experiments of plate confrontation antibacterial, disease prevention and field growth promotion. The strain was identified as Pseudomonas sp. A34-9. The experiment showed that the Pseudomonas sp. A34-9 had inhibitory effects on multiple Fusarium, Phytophthora and Rhizoctonia solani, and the control effect on Fusarium solani was 59.69% and the control effect on Phytophthora was 75%.

[0017] The pseudomonas of the present invention can biologically control soil-borne diseases caused by plant pathogenic fungi such as various Fusarium (Fusarium oxysporum, Fusarium solani, Fusarium laminaria, Fusarium pseudograminearum, Fusarium graminearum, Fusarium equisetum), Rhizoctonia solani, and Phytophthora, and can increase the yield of crops such as Salvia miltiorrhiza, yam, Atractylodes macrocephala, honeysuckle, wheat, and peanuts.

[0018] The Pseudomonas selected by the present invention has a good use effect and will not produce common problems of chemical pesticides such as drug resistance, pesticide residues, and environmental pollution after use. It is healthy for humans and animals, environmentally friendly, and meets people's needs for ecological agriculture. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 This is a comparison of the growth promotion of Salvia miltiorrhiza rhizomes by strain A34-9 in field application in Example 6.

[0020] In the figure, CK: control treatment, 3: strain A34-9 treatment.

[0021] Figure 2 This is a comparison of the growth promotion of yam rhizomes in field applications of strain A34-9 in Example 8.

[0022] Figure 3 This is the effect of strain A34-9 in Example 12 on the growth of peanuts in the field. DETAILED DESCRIPTION

[0023] The specific implementation modes of the present invention are further described in detail below in conjunction with the embodiments.

[0024] Experimental Materials:

[0025] KB medium: 20 g of peptone, 10 ml of glycerol, 1.5 g of dipotassium hydrogen phosphate, 1.5 g of magnesium sulfate heptahydrate, 20 g of agar (added only when making solid culture medium), add distilled water to make up to 1000 ml, mix well and dispense into Erlenmeyer flasks, and sterilize at 121°C for 30 min.

[0026] PDA culture medium: 200 g potato (cut into small pieces with a side length of about 1 cm, put into 800 ml distilled water and boil for 15 min, filter through double gauze and keep the filtrate), 20 g glucose, 20 g agar, add distilled water to make up to 1000 ml, sterilize at 121°C for 30 min.

[0027] The pathogenic bacteria and other raw materials and reagents used in the present invention are all purchased from the market.

[0028] Example 1, separation of biocontrol bacteria

[0029] Rhizosphere soil of tobacco plants was collected in Arshan, Inner Mongolia. 1 g of soil was weighed and added into 10 ml of sterile water and shaken thoroughly to obtain a soil suspension. The soil suspension was then shaken and diluted in multiples. 0.1 ml of the dilution was spread on KB solid culture medium and incubated upside down in a constant temperature incubator at 28°C for 36 h until colonies grew. Colonies of different sizes, colors or shapes were picked and streaked on the surface of KB solid culture medium for separation and purification to obtain a strain named P34-9.

[0030] Example 2: Inhibition of various fungal pathogens by biocontrol bacteria

[0031] Screening of biocontrol bacteria using plate confrontation method: Inoculate a variety of fungal pathogens (see Table 1 for details) on PDA medium, culture at 28°C for 5-10 days, and punch the pathogen colonies into circular mycelium blocks with a diameter of 5 mm using a sterilized puncher. Inoculate the pathogen blocks and the isolated strain (P34-9) on PDA medium, with a distance of 20 mm between the pathogen blocks and the isolated strain, and set up a separate inoculation of pathogen blocks as a control. Each treatment was repeated 3 times, and the confrontation culture results were checked after the control fungi grew all over the plate. The results are shown in Table 1. P34-9 has a certain inhibition rate against multiple pathogens (Table 1).

[0032] Table 1 The antibacterial results of a strain isolated from Arshan soil against various fungal pathogens

[0033]

[0034] Determination of antibacterial activity of fermentation filtrate of isolated strain: take strain P34-9 cultured for 24 hours, inoculate it into 100 ml KB culture medium, ferment it in a shake flask at 28°C and 180 rpm for 2 days, retain the filtrate after centrifugation, filter it twice with a microporous filter membrane (stored at 4°C), and then prepare PDA plates containing 300 ml / l of filtrate, inoculate a 5 mm pathogenic bacteria block in the center of each plate, and culture it at a constant temperature of 28°C. Observe the results after 5 days.

[0035] The results showed that strain P34-9 had a good inhibitory effect on Phytophthora, Fusarium solani and Fusarium oxysporum.

[0036] Example 3, identification of biocontrol bacteria

[0037] Morphology and physiological biochemistry of strains: Gram staining of strain P34-9 is negative. On KB medium, the colony morphology after culturing at 28℃ for 48h is round and convex, with a smooth and moist surface, milky white to slightly yellow, translucent, and sticky when picked up. There is a diffusible fluorescent pigment on the medium (only visible under UV2). It can grow at 5℃, but not at 41℃. Arginine dihydrolase, oxidase and gelatin liquefaction are positive, nitrate reduction and denitrification tests, methyl red and VP tests are all negative, and it cannot hydrolyze starch.

[0038] Sequencing: The genome of strain P34-9 was sequenced, and the results showed that the nucleic acid sequence had a high score with Pseudomonas fluorescens strain ATCC13525 and Pseudomonas RU47 (P.sp.RU47). According to the ANI analysis results, the similarity between the strain and Pseudomonas RU47 (P.sp.RU47) was as high as 91%, so the strain was comprehensively identified as Pseudomonas sp. A34-9 A34-9. A34-9 was sequenced, and its GenBank accession number is CP119967.

[0039] Pseudomonas sp. A34-9 has been deposited in the China Center for Type Culture Collection, with the deposit number: CCTCC NO: M 2022397 and the deposit date: April 8, 2022.

[0040] Example 4: Test on the allergenicity of biocontrol bacteria to tobacco leaves

[0041] Pseudomonas A34-9 cultured at 28°C for 24 h was diluted with 10 mM MgSO4 to 10 7 ~10 8 CFU / ml(OD 600 In the presence of 0.3-0.5% bacterial solution, ordinary tobacco leaves were injected and inoculated. Under the conditions of 24°C and 60%-80% high humidity, the appearance of allergic necrotic spots after 24-48 hours was considered a positive reaction, and the appearance of relatively transparent yellow spots after 3 days was considered a negative reaction. Inoculation with 10mM MgSO4 was used as a negative control, and 10 7 ~10 8 CFU / ml tobacco wildfire pathogen injection inoculation was used as the positive control.

[0042] The results showed that the allergy test of Pseudomonas A34-9 was negative, so Pseudomonas A34-9 was non-pathogenic and could be used as a potential biocontrol bacterium.

[0043] Example 5: Biocontrol bacteria growth promotion test on Salvia miltiorrhiza potted plants

[0044] The preparation method of Pseudomonas A34-9 fermentation broth is as follows: Pseudomonas A34-9 is inoculated into KB medium, and shaken and cultured for 16 hours at 28°C and 180 rpm to prepare seed bacteria, and the seed bacteria is inoculated into KB medium at an inoculum amount of 3% (v / v), and fermented for 48 hours at 28°C and 180 rpm to form a fermentation broth; the concentration of live Pseudomonas in the fermentation broth is 10 9 ~10 10 CFU / ml.

[0045] When using, dilute the fermentation liquid 10 times with sterile water, and the concentration of live bacteria in the dilution liquid is 10 8 ~10 9 CFU / ml.

[0046] Select 3-4 true-leaf Salvia miltiorrhiza seedlings with consistent growth and transplant them into pots filled with sterilized soil and substrate in a volume ratio of 3:1, with one plant per pot. Use root irrigation to inoculate Pseudomonas A34-9: 3-5 days after transplanting, moisten the soil with a small amount of clean water, and then use a pipette tip to transfer Pseudomonas A34-9 fermentation liquid (10 8 CFU / ml) was poured into the rhizosphere of the plants, 10 ml / plant, and then the roots were irrigated once every 7 days, for a total of 2 times; the control group was inoculated with an equal amount of KB medium (CK) in the same way. After inoculation of biocontrol bacteria, water was poured once every 3 days and cultured in a 25℃ greenhouse. The growth of Salvia miltiorrhiza seedlings was investigated after 30 days of culture.

[0047] The results showed that Pseudomonas A34-9 had a good promoting effect on the growth of Salvia miltiorrhiza and could effectively increase the fresh weight of Salvia miltiorrhiza roots (Table 2).

[0048] Table 2 Effect of Pseudomonas A34-9 on the growth promotion of potted Salvia miltiorrhiza seedlings

[0049] deal with Number of main roots (roots) Number of lateral roots (roots) Root weight (g) Root fresh weight increase rate (%) A34-9 1 4.13 2.31 35.09 CK 1 4.10 1.71 -

[0050] Example 6: Field growth promotion test of biocontrol bacteria on Salvia miltiorrhiza

[0051] The preparation method of Pseudomonas A34-9 fermentation broth is the same as that in Example 5.

[0052] In the field of annual Salvia miltiorrhiza with uniform growth, apply the fermentation liquid of Pseudomonas A34-9 during the vigorous growth period of Salvia miltiorrhiza roots from the end of June to the end of July. Use the stem base spray method to inoculate the biocontrol bacteria, and apply 3 liters of Pseudomonas A34-9 fermentation liquid (live bacteria concentration of 2×10 9 CFU / ml), and repeated inoculation twice, with an interval of 30 days. The control group was inoculated with the same amount of KB medium (CK) in the same way. The field cultivation conditions and water and fertilizer management were the same, and no chemical pesticides were used. When the salvia miltiorrhiza harvest period came, the plants were carefully dug out, the soil at the roots was washed off, and the number of salvia miltiorrhiza roots and yield in the treatment and control areas were measured and recorded.

[0053] The results showed that Pseudomonas A34-9 could promote the root length, taproot thickness and yield of Salvia miltiorrhiza, indicating that Pseudomonas A34-9 has a good growth-promoting effect ( Figure 1 , Table 3).

[0054] Table 3 Growth-promoting effect of Pseudomonas A34-9 on Salvia miltiorrhiza

[0055]

[0056] Example 7: Experiment on the effect of biocontrol bacteria on rooting and germination of yam stem segments

[0057] The preparation method of Pseudomonas A34-9 fermentation broth is the same as that in Example 5.

[0058] The 8 cm long yam stem segments were uniformly selected for the budding and growth promotion test of the biocontrol bacteria Pseudomonas A34-9. The immersion method was adopted: the yam stem segments were immersed in the fermentation liquid of Pseudomonas A34-9 (the concentration of live bacteria was 2×10 8 CFU / ml), and then dried naturally after soaking, and transplanted to the sand bed of the greenhouse for germination culture. The KB medium was used as the control, and the water control (soaked in water) and the blank control (no treatment) were set up for rooting and germination test.

[0059] The results showed that soaking yam stem segments in Pseudomonas A34-9 for 2 hours can significantly promote the length and number of yam fibrous roots, promote the growth of aerial stems, and increase the germination rate of yam stem segments (Table 4). As can be seen from Table 4, soaking yam stem segments in Pseudomonas A34-9 can effectively increase the germination rate of yam stem segments, increase the length of fibrous roots and the length of aerial stems.

[0060] Table 4 Effects of Pseudomonas A34-9 on rooting and germination of yam stem segments

[0061]

[0062] Example 8: Field growth promotion test of biocontrol bacteria on Chinese yam

[0063] The preparation method of Pseudomonas A34-9 fermentation broth is the same as that in Example 5.

[0064] In the yam field with uniform growth, apply the fermentation liquid of Pseudomonas A34-9, a biocontrol bacteria, during the vigorous growth period of yam underground stems from the end of June to the end of July. Use the stem base spray method to inoculate the biocontrol bacteria, and apply 2-3 liters of Pseudomonas A34-9 fermentation liquid (live bacteria concentration of 2×10 9 CFU / ml), repeated inoculation twice, with an interval of 30 days, and the control group was inoculated with the same amount of KB medium (CK) in the same way. The field cultivation conditions and water and fertilizer management were consistent, and no chemical pesticides were used. When the yam underground stems were harvested, the plants were carefully dug out, the soil at the roots was washed off, and the length of the yam underground stems and the yield of the plots in the treatment and control areas were measured and recorded.

[0065] The results showed that Pseudomonas A34-9 could promote the length of rhizomes and yield per plant of yam. Figure 2 , Table 5).

[0066] Table 5 Growth-promoting effect of Pseudomonas sp. A34-9 on field yam

[0067]

[0068] Example 9: Field growth promotion test of biocontrol bacteria on Atractylodes macrocephala

[0069] The preparation method of Pseudomonas A34-9 fermentation broth is the same as that in Example 5.

[0070] In the field of Atractylodes macrocephala with uniform growth, the fermentation liquid of Pseudomonas A34-9 was applied during the vigorous growth period of the underground rhizomes of Atractylodes macrocephala from the end of June to the end of July. The biocontrol bacteria were inoculated by spraying the stem base, and 1 liter, 2 liters, and 3 liters of Pseudomonas A34-9 fermentation liquid (live bacteria concentration of 2×10 9 CFU / ml), repeated inoculation twice, with an interval of 30 days, and the control group was inoculated with the same amount of KB medium (CK) in the same way. The field cultivation conditions and water and fertilizer management were the same, and no chemical pesticides were used. When the rhizomes of Atractylodes macrocephala were harvested, the whole plant was carefully dug out, the soil at the root was washed off, and the rhizomes of the treatment and control areas were measured and recorded in the plot.

[0071] The results showed that Pseudomonas A34-9 had a significant promoting effect on the underground rhizomes of Atractylodes macrocephala (Table 6). Using 1-2 liters of Pseudomonas A34-9 per mu can effectively increase the plant height of Atractylodes macrocephala, the number of seedlings in the plot, and increase the yield of the plot by more than 30%.

[0072] Table 6 Effect of Pseudomonas A34-9 on the growth promotion of Atractylodes macrocephala

[0073]

[0074] Example 10: Field growth promotion test of biocontrol bacteria on honeysuckle

[0075] The preparation method of Pseudomonas A34-9 fermentation broth is the same as that in Example 5.

[0076] In the honeysuckle field with uniform growth, the fermentation liquid of Pseudomonas A34-9 was applied during the early spring when the flower buds of honeysuckle sprouted and the rapid growth period of stems and leaves. The biocontrol bacteria were inoculated by root irrigation or spraying, and 2, 3, and 5 liters of Pseudomonas A34-9 fermentation liquid (live bacteria concentration of 2×10 9 CFU / ml), repeated inoculation twice, with an interval of 30 days, and the control group was inoculated with 5 liters of KB medium (CK) in the same way. The field cultivation conditions and water and fertilizer management were consistent, and no chemical pesticides were used. When the first batch of honeysuckle (Four Seasons Flower) was harvested, the plot yield was measured.

[0077] The results showed that the use of Pseudomonas A34-9 inoculant at 1-5 liters per mu could effectively promote the length of the first flower buds, the weight of 100 needles, and the cumulative first flower yield of honeysuckle (Table 7).

[0078] Table 7 Growth-promoting effect of Pseudomonas A34-9 on honeysuckle

[0079]

[0080] Example 11: Experiment on increasing wheat yield by biocontrol bacteria

[0081] The preparation method of Pseudomonas A34-9 fermentation broth is the same as that in Example 5.

[0082] In the wheat fields with uniform growth, the fermentation liquid of Pseudomonas A34-9 was applied when the wheat had one leaf and one heart. The biocontrol bacteria were inoculated by spraying, and 1 liter and 1.5 liter of Pseudomonas A34-9 fermentation liquid (live bacteria concentration of 2×10 9 CFU / ml), inoculated once, and the control group was inoculated with 1.5 liters of KB medium (CK) in the same way. The field cultivation conditions and water and fertilizer management were the same, and no chemical pesticides were used. When the wheat was harvested, the plot yield was measured.

[0083] The results showed that Pseudomonas A34-9 could promote wheat tillering, increase wheat stem diameter, and increase wheat yield, and had a significant promoting effect on wheat growth and yield (Table 8).

[0084] Table 8 Growth-promoting effect of Pseudomonas A34-9 on wheat

[0085] project A34-9 1L / acre A34-9 1.5L / mu CK Plant height (cm) 34.12 34.32 34.02 Number of tillers 3.36 3.25 3.05 Stem diameter (mm) 3.46 3.19 2.95 Number of grains / ear 37.00 44.33 36.87 <![CDATA[Yield of plot (g / 0.25 m 2 )]]> 254.30 257.50 202.33

[0086] Example 12: Experiment on increasing peanut production by biocontrol bacteria

[0087] The preparation method of Pseudomonas A34-9 fermentation broth is the same as that in Example 5.

[0088] In the peanut fields with uniform growth, the fermentation liquid of Pseudomonas A34-9 was applied from the seedling stage to the flowering stage in late June. The biocontrol bacteria were inoculated by spraying, and 2 liters of Pseudomonas A34-9 fermentation liquid (live bacteria concentration of 2×10 9 CFU / ml), inoculated once, and the control group was inoculated with 2 liters of KB medium (CK) in the same way. The field cultivation conditions and water and fertilizer management were the same, and no chemical pesticides were used.

[0089] During the peanut fruit-full maturity stage, the plant height, the number of peanut plants in the sample plot, the length of the first pair of branches, the number of nodes within 15 cm, the fruit-free needle rate, the fruit-full rate, and the number of branches were measured. During the peanut harvest period, the fresh weight of pods of 10 peanut plants was investigated, the fruit-free needle rate, and the occurrence of root rot were determined. After drying, the weight of 100 pods and 100 kernels was determined.

[0090] As can be seen from Table 9, Pseudomonas A34-9 can effectively increase the number of peanut plants per unit area, reduce plant height and the length of the first pair of branches, and increase the number of nodes within 15 cm. Theoretically, it can effectively increase the peanut fruiting rate. At the same time, it can reduce the fruit-free needle rate. In the final harvest period, it was found that Pseudomonas A34-9 can effectively increase the weight of 100 kernels and 100 pods, and effectively increase the peanut yield (Table 9). Figure 3 It can be seen that the growth of peanuts grown using strain A34-9 in the field is significantly better than that of the control group.

[0091] Table 9 Growth-promoting effect of Pseudomonas A34-9 on peanut

[0092] project CK A34-9 Average plant height (cm) 46.89 42.83 <![CDATA[Average number of plants per quadrat (plants / 0.8m 2 )]]> 24.4 31 Length of the first pair of branches (cm) 50.70 46.69 15cm Sections 3.77 4 Ineffective needle insertion rate (%) 16.15 12.61 Fruit fullness rate (%) 30.26 30.54 Number of branches 8.7 8.7 Fresh weight yield of peanut pods per 10 plants (g) 283.63 347.50 Yield increase rate (%) 0 22.52 Dry rate 58.21 58.96 Ineffective needle insertion rate (%) 18.15 14.00 Fruit fullness rate (%) 42.55 44.42 100 pod weight 127.35 130.47 Bairenzhong 56.51 58.97 Root rot prevention effect (%) 0 52.87

[0093] The above is only a preferred embodiment of the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any possible modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A Pseudomonas capable of inhibiting plant pathogens and promoting growth, characterized in that: The Pseudomonas is Pseudomonas sp. A34-9, which has been deposited in the China Center for Type Culture Collection, with a deposit number of CCTCC NO: M 2022397 and a deposit date of April 8, 2022.

2. The Pseudomonas according to claim 1, characterized in that The plant pathogens include: Fusarium, Rhizoctonia solani, and Phytophthora.

3. The Pseudomonas according to claim 2, characterized in that The Fusarium includes: Fusarium asiatica, Fusarium equisetum, Fusarium graminearum, Fusarium pseudograminearum, Fusarium solani, Fusarium oxysporum.

4. The Pseudomonas according to claim 1, characterized in that The plants include: salvia miltiorrhiza, yam, atractylodes macrocephala, honeysuckle, wheat and peanut.

5. A method for preparing a fermentation liquid when the Pseudomonas according to claim 1 is used to promote plant growth, characterized in that: The method comprises the following steps: inoculating Pseudomonas A34-9 in KB culture medium, oscillating and culturing at 28°C and 180 rpm for 16 hours to prepare seed bacteria; inoculating the seed bacteria in KB culture medium at an inoculation rate of 3% (v / v), fermenting at 28°C and 180 rpm for 48 hours to form a fermentation liquid; the concentration of live Pseudomonas in the fermentation liquid is 10 9 ~10 10 CFU / mL.

6. The preparation method according to claim 5, characterized in that: KB culture medium includes: 20 g of peptone, 10 mL of glycerol, 1.5 g of dipotassium hydrogen phosphate, 1.5 g of magnesium sulfate heptahydrate, add distilled water to make up to 1000 mL, mix well and dispense into Erlenmeyer flasks, and sterilize at 121°C for 30 min.

7. A use of the Pseudomonas according to claim 1 in inhibiting plant pathogens, characterized in that: The plant pathogens are Fusarium, Rhizoctonia solani and Phytophthora.

8. Use of the Pseudomonas as claimed in claim 1 in promoting the growth of Salvia miltiorrhiza, Dioscorea opposita, Atractylodes macrocephala, Flos lonicerae, wheat and peanut.

9. Use of the Pseudomonas according to claim 1 in preventing and controlling the soil-borne disease root rot of peanut crops.

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