Pseudomonas luminescens and use thereof

Abstract

This application relates to a strain of *Pseudomonas lundense* and its applications. The present invention isolates a strain of *Pseudomonas lundense* from the root soil of rice plants in a rice cultivation base. This strain is effective against rice basal rot pathogens (…). Dickeya oryzae ), potato soft rot fungus ( Dickeya dadantii ), and Taro soft rot fungus ( Dickeya fangzhongdai It has a good control effect on sugarcane smut ( ) Sporisorium scitamineum ), rice blast fungus ( Magnaporthe oryzae ), Neodatura spp. Neoscytalidium dimidiatum ), neatly arranged small sclerotia ( Sclerotium rolfsii ), Lithocarpus ( Calonectria ), Black spores ( Nigrospora lacticoloni a) Ralstonia solanacearum ( Ralstonia solanacearum Xanthomonas aeruginosa (), Xanthomonas campestris pv. Campestris ) and citrus canker pathogen ( Xanthomonas citri subsp. citri It also has a good control effect. Therefore, it can be widely used in the control of plant diseases, including rice basal rot.

Description

Technical Field

[0001] This application relates to the field of biological control technology, and in particular to a type of *Pseudomonas lundii* and its applications. Background Technology

[0002] Bacterial basal rot of rice is caused by Digitrophus oryzae (… Dickeya oryzae This disease, caused by [unspecified pathogen], was first discovered in Japan in the late 1970s and is a potential threat to rice production safety. Due to its sporadic, sudden, and severe nature, it significantly reduces grain yield and jeopardizes food security. Furthermore, D. oryzae It has the ability to infect both monocotyledonous and dicotyledonous plants.

[0003] Bacterial basal rot of rice mainly occurs at the base of the stem and roots. During seed germination, it can lead to rotten buds and seeds. In the field, infected plants begin to blacken at the base of the stem, gradually causing root rot, and can also cause stem rot in other plants such as corn. As the disease progresses, the rootstock of diseased plants is easily broken. After infection during the heading stage, the plants first lose water and wilt, forming withered panicles, semi-wilted panicles, and withered panicles, exhibiting acute wilt and seedling death. It can also lead to white panicles and reduced tillering.

[0004] The earliest discovered rice basal rot pathogen in my country was Erwin's chrysanthemum maize pathogen (… Erwinia chrysanthemi pv. zeae This pathogen can infect both monocotyledonous and dicotyledonous plants, including many important food crops and flowers, such as rice, tobacco, corn, banana, potato, radish, sugarcane, chrysanthemum, pineapple, and taro, and can cause soft rot, wilt and dwarfing in a variety of plants. Dickeya There are many species, and through long-term adaptation and evolution, their host range has continued to expand. Currently Dickeya The main species contained in spp include: D. chrysanthemi , D. dadantii , D. diffenbachiae , D. dianthicola , D. paradisiaca , D. zeae , D. solani , D. aquatica , D. fangzhongdai , D. undicola , D. lacustris , D. poaceiphila , D. oryzae , D. parazeae and D. dadantii (subsp. paradisiaca).

[0005] In recent years, crop production has faced serious threats due to various biotic and abiotic stresses. Current agricultural practices, such as the use of chemical fertilizers, pesticides, herbicides, and irrigation with untreated wastewater, pose a serious threat to the environment and lead to soil degradation. Therefore, increasing crop yields per unit area by preventing further degradation of natural resources is of paramount importance. Thus, adopting alternative methods in today's agriculture is essential to ensuring environmental sustainability and future food security. Summary of the Invention

[0006] The purpose of this invention is to overcome the shortcomings of the prior art and provide a *Pseudomonas lundii* strain and its applications.

[0007] The first objective of this invention is to provide a *Pseudomonas lundii* strain. Pseudomonas lundensis .

[0008] A second objective of this invention is to provide the application of the aforementioned *Pseudomonas lundense* and / or its fermentation broth in the inhibition of plant pathogenic fungi.

[0009] A third objective of this invention is to provide the application of the aforementioned *Pseudomonas lundense* and / or its fermentation broth in the inhibition of plant pathogenic bacteria.

[0010] A fourth objective of this invention is to provide the use of the aforementioned *Pseudomonas lundensis* and / or its fermentation broth in the preparation of biocontrol agents for the control of plant diseases or pathogenic fungi that cause plant diseases.

[0011] A fifth objective of this invention is to provide the use of the aforementioned *Pseudomonas lundensis* and / or its fermentation broth in the preparation of biocontrol agents for the prevention and control of plant diseases or pathogenic bacteria that cause plant diseases.

[0012] A sixth object of the present invention is to provide the application of the aforementioned *Pseudomonas lundensis* and / or its fermentation broth in the control of plant diseases.

[0013] To achieve the above objectives, the present invention is implemented through the following technical solution: A type of Lund Pseudomonas Pseudomonas lundensis It was deposited at the Guangdong Provincial Center for Microbial Culture Collection on February 3, 2026, with accession number GDMCC No: 67792.

[0014] The application of *Pseudomonas lundensis* and / or its fermentation broth in inhibiting plant pathogenic fungi, wherein the plant pathogenic fungi are: *Ustilago maydis* (Sugarcane smut). Sporisorium scitamineum Rice blast fungus ( Magnaporthe oryzae ), Neodatura spp. Neoscytalidium dimidiatum ), neatly arranged small sclerotia ( Sclerotium rolfsii ), Lithocarpus ( Calonectria ) and Ichthyophthirius multifiliis ( Nigrospora lacticoloni a).

[0015] The application of *Pseudomonas lundensis* and / or its fermentation broth in inhibiting plant pathogenic bacteria, wherein the plant pathogenic bacteria are *Digitaria* spp. Dickeya ) or Ralstonia solanacearum ( Ralstonia solanacearum ).

[0016] Preferably, the *Digitaria* genus ( Dickeya ) is rice dystrophia ( D. oryzae ), potato soft rot fungus ( D. dadantii ), or taro soft rot fungus ( D. fangzhongdai ).

[0017] The application of *Pseudomonas lundensis* and / or its fermentation broth in the preparation of biocontrol agents for controlling or causing plant diseases by pathogenic fungi, wherein the plant diseases are caused by pathogenic fungi, and the pathogenic fungi are: *Ustilago maydis* (Sugarcane smut). S. scitamineum Rice blast fungus ( M. oryzae ), Neodatura spp. N. dimidiatum ), neatly arranged small sclerotia ( S. rolfsii ), Lithocarpus ( Calonectria ) and Ichthyophthirius multifiliis ( N. lacticoloni a).

[0018] The application of *Pseudomonas lundensis* and / or its fermentation broth in the preparation of biocontrol agents for controlling or causing plant diseases by pathogenic bacteria, wherein the plant diseases are caused by pathogenic bacteria, and the pathogenic bacteria are *Digibium* spp. Dickeya ) or Ralstonia solanacearum ( R. solanacearum ).

[0019] Preferably, the *Digitaria* genus ( Dickeya ) is rice dystrophia ( D. oryzae ), potato soft rot fungus ( D. dadantii ), or taro soft rot bacteria ( D. fangzhongdai ).

[0020] The application of *Pseudomonas lundensis* and / or its fermentation broth in the control of plant diseases, wherein the plant diseases are caused by pathogenic fungi, and the pathogenic fungi are: *Ustilago maydis* (Sugarcane smut). S. scitamineum Rice blast fungus ( M. oryzae ), Neodatura spp. N. dimidiatum ), neatly arranged small sclerotia ( S. rolfsii ), Lithocarpus ( Calonectria ) and Ichthyophthirius multifiliis ( N. lacticoloni a).

[0021] The application of *Pseudomonas lundensis* and / or its fermentation broth in the control of plant diseases, wherein the plant diseases are caused by pathogenic bacteria, and the pathogenic bacteria are *Digitaria* spp.Dickeya ) or Ralstonia solanacearum ( R. solanacearum ).

[0022] Preferably, the *Digitaria* genus ( Dickeya ) is rice dystrophia ( D. oryzae ), potato soft rot pathogen ( D. dadantii ), or taro soft rot bacteria ( D. fangzhongdai ).

[0023] Compared with the prior art, the present invention has the following beneficial effects: This invention isolated a strain of *Pseudomonas lundensis* from the root soil of rice plants in a rice cultivation base. This strain is effective against rice basal rot pathogens (…). D. oryzae ), potato soft rot pathogen ( D. dadantii ) and Taro soft rot fungus ( D. fangzhongdai It has a good control effect on sugarcane smut ( ) S. scitamineum Rice blast fungus ( M. oryzae ), Neodatura spp. N. dimidiatum ), neatly arranged small sclerotia ( S. rolfsii ), Lithocarpus ( Calonectria ), Black spores ( N. lacticoloni a) Ralstonia solanacearum ( R. solanacearum Xanthomonas aeruginosa (), Xanthomonas campestris pv. Campestris ) and citrus canker pathogen ( Xanthomonas citri subsp. citri It also has a good control effect. Therefore, it can be widely used in the control of plant diseases, including rice basal rot. Attached Figure Description

[0024] Figure 1 pathogens D. oryzae EC1 and D. dadantii 3937 had no inhibitory effect on strain XY3.

[0025] Figure 2 Phylogenetic analysis of 16S rDNA from strain XY3.

[0026] Figure 3 The addition of XY3 bacterial solution increased the germination rate of rice seeds infected with EC1.

[0027] Figure 4 XY3 can alleviate D. dadantii Symptoms of radish infection caused by 3937.

[0028] Figure 5 XY3 can alleviateD. dadantii Symptoms of infection in potatoes (3937).

[0029] Figure 6 XY3 can alleviate D. dadantii Symptoms of infection in Chinese cabbage (3937). Detailed Implementation

[0030] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application. Unless otherwise specified, the experimental methods used in the following embodiments are conventional methods; the materials and reagents used, unless otherwise specified, are commercially available.

[0031] 1. Test strains Wild-type strain of rice basal rot fungus D. oryzae EC1. Culture conditions and preservation of strains: Except for Ralstonia solanacearum (… R. solanacearum Except for TTC medium, EC1 strain and other plant pathogenic bacteria strains were cultured on LB medium, and plant pathogenic fungi strains were cultured on PDA medium at 28 ℃; Escherichia coli strains were cultured on LB medium at 37 ℃.

[0032] D. oryzae EC1, D. dadantii 3937、 D. fangzhongdai ZXC, R. solanacearum EP1 X. campestris pv. campestris XC1, X. citri subsp. citri jx- 6. S. scitamineum , M. oryzae B27 N. dimidiatum , S. rolfsii , Calonectria spp., and N. lacticolonia All of the above strains were obtained from our laboratory.

[0033] 2. Culture medium The culture medium was sterilized at 121 °C for 20 minutes. The solid culture medium used in the test was the corresponding liquid culture medium with 15 g / L of agar powder added.

[0034] LB medium: 10 g / L tryptone, 10 g / L sodium chloride (NaCl), 5 g / L yeast extract, pH 7.0, dissolved in ddH2O to a final volume of 1 L.

[0035] TTC medium: 10.0 g peptone, 5.0 g sodium chloride, 3.0 g beef extract, 15.0 g agar powder.

[0036] PDA medium: Potato 200 g, glucose 20 g, agar 15 g, pH 7.0, dissolved in ddH2O to a final volume of 1 L.

[0037] 3. Buffer formulation 0.5×TBE electrophoresis buffer: Tris 108 g, Boric acid 55 g, Na2EDTA·H2O 7.44 g, dissolved in 20 L ddH2O.

[0038] 4. Test reagents 2×EasyTaq PCR SuperMix was purchased from Nanjing Novizan Biotechnology Co., Ltd., Goldmix (green) was purchased from Beijing Qingke Biotechnology Co., Ltd., Trans5K DNA Marker, Trans2K DNA Marker, Trans5α Chemically Competent Cell, and 10×DNA loading buffer were purchased from Beijing TransGen Biotech Co., Ltd., and Goldview nucleic acid dye was purchased from Beijing Dingguochangsheng Biotechnology Co., Ltd.

[0039] Example 1: Antagonistic bacteria of rice basal rot pathogen isolated from soil I. Experimental Methods 1. Isolation of soil strains Rice root soil samples were selected from a rice planting base in Tianhe District, Guangzhou City, Guangdong Province. 1 g of soil sample was serially diluted 10... 1 10 2 10 3 10 4 Take 100 µL of each serial dilution and spread it on LB agar plates. Incubate at 28 °C upside down for 16 h until a single colony grows. Save the strains for further selection of antagonistic bacteria.

[0040] 2. Selection of antagonistic strains Pour 12.5 mL of LB medium into a 13×13 cm Petri dish and let it solidify. Take the cells of overnight cultured strains EC1 and 3937, and add them separately to 1% agarose at a volume ratio of 1:100 at approximately 40 °C. Mix well to obtain an agarose mixture. Pour 17.5 mL of the agarose mixture onto the solidified LB medium. After solidification, punch holes with a 5 mm punch and remove the medium from the holes with a toothpick.

[0041] Single colonies isolated from soil were picked and inoculated into 1 mL of fresh liquid LB medium and incubated at 28 ℃ and 200 rpm for 16 h. 20 µL of the seed culture was then added to the wells of a plate and incubated overnight at 28 ℃.

[0042] The above steps should be repeated at least three times to obtain strains with stable antagonistic effects.

[0043] II. Experimental Results Soil samples from the rhizosphere area of ​​healthy rice plants were collected, diluted, and cultured before being isolated onto LB agar plates. The obtained bacteria were then inoculated onto plates containing... D. oryzae EC1 or D. dadantii In culture medium plates containing 3937, the size of the inhibition zone was used to determine its inhibitory effect. D. oryzae EC1 and D. dadantii Using the strength of 3937 as a screening criterion, approximately 200 strains with inhibitory effects were screened out. D. oryzae Antagonistic bacteria to EC1 growth activity.

[0044] Among them, pathogens D. oryzae EC1 and D. dadantii 3937 had no inhibitory effect on strain XY3; strain XY3 was found in EC1 or D. dadantii Under the growth environment of 3937, a significant antibacterial zone is formed (see...). Figure 1 ).

[0045] Example 2 Identification of XY3, an antagonist to the wild-type strain EC1 of rice basal rot fungus I. Morphological Observation 1. Experimental Methods After isolating and purifying XY3, an antagonist of the wild-type strain EC1 of rice basal rot fungus, the strains were preliminarily screened and identified by observing the morphological characteristics of the isolates on LB plates, such as colony morphology, color, transparency, size, edge shape, and moisture content.

[0046] 2. Experimental Results After 24 hours of incubation at 25°C on LB medium, the colonies are round, 1-4 mm in diameter, light green, and do not produce fluorescent pigments. The colonies are slightly raised, with a smooth, moist and glossy surface, a creamy and viscous texture that is easy to pick up, and neat or slightly wavy edges. The colonies are translucent, with a relatively solid center and slightly transparent edges.

[0047] II. 16S rDNA Identification 1. Experimental Methods Using the antagonistic bacterium XY3 as a template, 16S rDNA primers 16S rDNA-1492R (5'-GGTTACCTTGTTACGACTT-3') and 16S rDNA-27F (5'-AGAGTTTGATCCTGGCTCAG-3') were synthesized to amplify the 16S rDNA fragment.

[0048] The reaction system configuration is shown in Table 1, and the reaction system configuration is shown in Table 2.

[0049] Table 1:

[0050] Table 2:

[0051] A 5 µL sample was loaded and analyzed by 1% agarose gel electrophoresis. A distinct band of approximately 1500 bp was observed. The corresponding PCR product was collected and sent to Sangon Biotech for sequencing. The sequencing results were compared with those on the NCBI website to preliminarily determine the genus of the biocontrol bacteria.

[0052] 2. Experimental Results XY3 strain and Pseudomonas Pseudomonas aeruginosa strain D2 and Pseudomonas sp.strain 206012 is in one branch, indicating that the genetic distance is close, and strain XY3 belongs to the genus Pseudomonas.

[0053] Example 3: Carbon source utilization of XY3, an antagonist of wild-type strain EC1 of rice basal rot fungus. I. Experimental Methods Using an inoculation loop, XY3 strain stored at -80 ℃ was streaked onto LB agar plates and incubated overnight at 28 ℃ until a single colony grew. The plates were then sent to the Guangdong Provincial Microbiology Testing Center for analysis. The main steps of the carbon source analysis experiment are as follows: Single colonies were inoculated into Biolog plates, and a bacterial suspension of the recommended turbidity was prepared according to the specifications. The bacterial suspension was then inoculated into microplates, and the microplates were capped. The microplates were incubated at 28 °C for a period of time, and the results were read and analyzed using the BIOLOG identification system.

[0054] II. Experimental Results A negative control without a carbon source and a positive control with D-glucose are shown in Table 3 (- indicates almost no difference from the negative control, no utilization; + indicates deep purple, strong utilization; W indicates slight color development, weak utilization). The results show that this strain can efficiently utilize substrates such as L-trehalose, L-aspartic acid, L-glutamic acid, and L-malic acid. It exhibits weak utilization of various monosaccharides, some organic acids, and amino acids. It cannot utilize most polysaccharides, sugar alcohols, and glycosides as carbon sources, and it shows poor tolerance to most antibiotics and poor adaptability to high-salt environments.

[0055] Table 3:

[0056] Based on the carbon source utilization of strain XY3 and the 16S rDNA identification results, and referring to the Bergers Manual of Bacterial Identification and the sequence alignment results in Example 2, XY3 is related to *Pseudomonas lundense*. Pseudomonas lundensis The closest kinship. Therefore, XY3 was identified as... P. lundensis XY3 was deposited on February 3, 2026, at the Guangdong Provincial Center for Microbial Culture Collection (Address: 5th Floor, Building 59, No. 100 Xianlie Middle Road, Guangzhou), with accession number GDMCC No: 67792, and taxonomic name: Pseudomonas lundensis .

[0057] Example 4: Antibacterial spectrum of XY3, an antagonist to wild-type strain EC1 of rice basal rot pathogen. I. Experimental Methods 1. Antagonizes bacteria Following the method in Example 1, the antagonistic bacterium XY3 Ralstonia solanacearum (Ralstonia solanacearum) was detected. R. solanacearum EP1), Xanthomonas oryzae ( X. campestris pv. Campestris XC1), Citrus canker pathogen ( X. citri subsp. citri ), rice basal rot pathogen ( D. oryzae ), potato soft rot pathogen ( D. dadantii ) and Taro soft rot fungus ( D. fangzhongdai The inhibitory effect of ).

[0058] 2. Confrontational fungi Select pathogenic fungi to be tested, including rice blast fungus (…). M. oryzae B27), dragon fruit canker pathogen (Neoplasmosis datura) N. dimidiatum White rot fungus (Sclerotium sclerotiorum) S. rolfsii Leaf scorch fungus (Erythrophagus erythrophagus) Calonectria ), Black spores ( N. lacticolonia The mycelium was attached to the center of a PDA plate (Φ = 9 cm), and 1 µLOD was taken at the same time. 600An antagonistic bacterium, XY3, at a concentration of 1.0 μL was inoculated 3 cm from the center of the agar plate. The plate was then inverted and incubated at 25 °C. The growth of pathogenic fungi not inoculated with antagonistic bacterium XY3 served as a control group. Once the mycelia of the pathogenic fungi in the control group had completely covered the agar plate, the width of the inhibition band formed by the antagonistic bacterium against the pathogenic fungi was measured and recorded. Each pathogenic fungal confrontation experiment was repeated three times.

[0059] Confrontation with sugarcane smut ( S. scitamineum Take 1 µL OD 600 Sugarcane smut fungus (1.0 g) was inoculated onto a 1 cm wide strip of PDA solid medium, with 1 µL OD inoculated on one side leaving a 1 cm margin. 600 The antagonistic bacterium XY3 with a growth factor of 1.0 was used. The plates were inverted and incubated in a 25 °C incubator. After 3 days, the width of the inhibition band formed by the antagonistic bacteria against sugarcane smut was measured and recorded. The experiment was repeated 3 times.

[0060] II. Experimental Results The results are shown in Table 4. XY3 exhibits antibacterial activity against various pathogenic bacteria, including Ralstonia solanacearum (Ralstonia solanacearum). R. solanacearum EP1), Xanthomonas oryzae ( X. campestris pv. Campestris XC1), Citrus canker pathogen ( X. citri subsp. citri jx-6), rice basal rot fungus ( D. oryzae EC1), potato soft rot fungus ( D.dadantii 3937) and Taro soft rot fungus ( D. fangzhongdai ZXC); XY3 against different pathogenic fungi, sugarcane smut ( S. scitamineum Rice blast fungus ( M. oryzae B27 Dragon fruit canker pathogen (Neopterospora davidiana) N. dimidiatum ), white rot fungus (Sclerotium sclerotiorum, S. rolfsii Leaf scorch fungus (Erythrophagus erythrophagus) Calonectria ) and Black Sporozoites N. lacticolonia Both have an inhibitory effect.

[0061] Table 4

[0062] Example 4: Antagonistic bacteria XY3 D. oryzae EC1's biocontrol effects I. Rice seed infection 1. Experimental Methods (1) Antagonistic bacteria XY3 and D. oryzae EC1 preparation: Select the streaked activated antagonistic bacteria XY3 and D. oryzaeEC1 cells were inoculated into fresh LB liquid medium and cultured at 28 °C and 200 rpm.

[0063] (2) Select healthy Huanghuazhan rice seeds, rinse them 3 times with ddH2O, divide them into 9 portions, each containing 30 rice seeds. One portion serves as a blank control, and the other eight portions serve as the inoculation control group and the inoculation experimental group, with 4 portions of each group, for later use.

[0064] (3) The antagonistic bacteria cultured in step (1) and D. oryzae EC1 OD 600 Set to 1.0, and D. oryzae EC1 diluted to 10 3 10 4 10 5 10 6 Prepare two groups of bacterial solutions (different dilutions are one group). Add an equal volume of antagonistic bacteria XY3 to one group and mix well (to obtain a homogeneous bacterial solution). Add an equal volume of sterile water to the other group and mix well (EC1 bacterial solution). Soak the seeds of the inoculation test group in step (2) in EC1 and antagonistic bacteria XY3 premixed bacterial solutions of different dilution concentrations. Soak the seeds of the inoculation control group in EC1 bacterial solutions of different dilution concentrations for 5 h at room temperature. Treat the blank control group with sterile water.

[0065] (4) After soaking, the seeds of the control group and the experimental group were rinsed three times with sterile water. The seeds of the blank control group, the inoculated control group and the inoculated experimental group were placed on a filter paper (placed in a 9 cm petri dish, and moistened with 3 mL of sterile water) and kept at a constant temperature of 25 ℃. After 7 days, the seed germination status was recorded, the root length and stem length were measured and photographed.

[0066] 2. Experimental Results The addition of XY3 bacterial solution increased the germination rate of rice seeds infected with EC1 (approximately 50% in the experimental group and approximately 10% in the control group), and the root and stem lengths of rice seeds infected with the antagonistic bacteria were significantly higher than those in the EC1 control group. Figure 3 ).

[0067] II. Radish Infection 1. Experimental Methods (1) Preparation of antagonistic bacteria and pathogens: Select the streaked activated antagonistic bacteria XY3 and pathogens. D. oryzae EC1 cells were inoculated into fresh LB liquid medium and cultured at 28 °C and 200 rpm.

[0068] (2) Cut the radish into slices about 1 cm thick, spread them flat on the filter paper in the tray, and let them dry until there is no obvious water.

[0069] (3) The OD values ​​of the antagonistic bacteria and pathogenic bacteria cultured in step (1) are compared. 600 Set the temperature to 1.0. Divide each pathogen into two portions. Add an equal volume of antagonistic bacteria XY3 to one portion and mix well to form the mixed bacterial solution for the inoculation test group. Add an equal volume of sterile water to the other portion and mix well to form the diluted bacterial solution for the inoculation control group. The blank control group consists entirely of sterile water.

[0070] (4) Take 1 µL of the mixed bacterial solution of the inoculation experimental group, the diluted bacterial solution of the inoculation control group and the sterile water of the blank control group and add them to the center of the radish slices respectively, and place them on the filter paper in the tray. Each group of experiments includes 3 replicates.

[0071] (5) Place sterile, water-moistened paper towels on the edge of the tray, seal the tray with plastic wrap, and avoid the sealing film touching the vegetable slices during the sealing process. Place it at 28 ℃ for about 18 hours and observe that the most severely rotten slices have rotted to the edge of the slices. Measure the rotten area.

[0072] 2. Experimental Results The results show that ( Figure 4 The addition of XY3 bacterial solution reduced the rot symptoms caused by EC1 infection of radishes.

[0073] Example 5: Biocontrol effect of antagonistic bacteria XY3 against other pathogens I. Experimental Methods 1. Potato infection (1) Preparation of antagonistic bacteria and pathogens: Select the streaked activated antagonistic bacteria XY3 and pathogens ( D dadantii 3937), respectively, were inoculated into fresh LB liquid medium and cultured at 28 ℃ and 200 rpm.

[0074] (2) Cut the potatoes into slices about 1 cm thick. Soak the potatoes in ddH2O 2-3 times to wash away the starch on the cross-section. Spread the potatoes flat on filter paper in a tray and let them dry until there is no obvious water.

[0075] (3) The subsequent steps are the same as (3) to (5) of “radish infection” in Example 4.

[0076] 2. Symptoms of infection in Chinese cabbage (1) Preparation of antagonistic bacteria and pathogens: Select the streaked activated antagonistic bacteria XY3 and pathogens ( D fangzhongdai ZXC) were inoculated into fresh LB liquid medium and cultured at 28 ℃ and 200 rpm.

[0077] (2) Cut the Chinese cabbage into square pieces of about 4×4 cm and let them dry until there is no obvious moisture.

[0078] (3) The subsequent steps are the same as (3) to (5) of “radish infection” in Example 4.

[0079] II. Experimental Results See results Figure 5 The results showed that XY3 could alleviate... D. dadantii Symptoms of infection in potatoes (3937); results are shown in […]. Figure 6 XY3 can alleviate D. fangzhongdai ZXC infection symptoms in Chinese cabbage. This indicates that XY is... D. dadantii 3937 and D. fangzhongdai ZXC has significant biocontrol effects.

Claims

1. A type of Lund Pseudomonas ( Pseudomonas lundensis ), characterized in that, On February 3, 2026, it was deposited in the Guangdong Microbial Culture Collection Center with the deposit number GDMCC No: 67792.

2. The application of *Pseudomonas lundensis* and / or its fermentation broth as described in claim 1 in inhibiting plant pathogenic fungi, characterized in that, The plant pathogenic fungus is: *Ustilago maydis* (Sugarcane smut fungus). Sporisorium scitamineum Rice blast fungus ( Magnaporthe oryzae ), Neodatura spp. Neoscytalidium dimidiatum ), neatly arranged small sclerotia ( Sclerotium rolfsii ), Lithocarpus ( Calonectria ) and Ichthyophthirius multifiliis ( Nigrospora lacticoloni a).

3. The application of *Pseudomonas lundensis* and / or its fermentation broth as described in claim 1 in inhibiting plant pathogenic bacteria, characterized in that... The plant pathogenic bacteria is Ralstonia solanacearum (Ralstonia solanacearum). Ralstonia solanacearum Xanthomonas aeruginosa (), Xanthomonas campestris pv. Campestris ), Citrus canker pathogen ( Xanthomonas citri subsp. citri ), Digib ( Dickeya ).

4. The application according to claim 3, characterized in that, The Digib ( Dickeya ) is the rice basal rot pathogen ( Dickeya oryzae ), potato soft rot pathogen ( Dickeya dadantii ) or taro soft rot bacteria ( Dickeya fangzhongdai ).

5. The use of *Pseudomonas lundensis* and / or its fermentation broth as described in claim 1 in the preparation of biocontrol agents for controlling or causing plant diseases by pathogenic fungi, characterized in that... The plant disease mentioned is a plant disease caused by a pathogenic fungus, and the pathogenic fungus is: Sugarcane smut (… Sporisorium scitamineum Rice blast fungus ( Magnaporthe oryzae ), Neodatura spp. Neoscytalidium dimidiatum ), neatly arranged small sclerotia ( Sclerotium rolfsii ), Lithocarpus ( Calonectria ) and Ichthyophthirius multifiliis ( Nigrospora lacticoloni a).

6. The use of *Pseudomonas lundensis* and / or its fermentation broth as described in claim 1 in the preparation of biocontrol agents for controlling or causing plant diseases, characterized in that... The pathogenic bacteria is Ralstonia solanacearum (Ralstonia solanacearum). Ralstonia solanacearum Xanthomonas aeruginosa (), Xanthomonas campestris pv. Campestris ), Citrus canker pathogen ( Xanthomonas citri subsp. citri ), Digib ( Dickeya ).

7. The application according to claim 6, characterized in that, The Digib ( Dickeya ) is the rice basal rot pathogen ( Dickeya oryzae ), potato soft rot pathogen ( Dickeya dadantii ) or taro soft rot bacteria ( Dickeya fangzhongdai ).

8. The application of *Pseudomonas lundensis* and / or its fermentation broth as described in claim 1 in the control of plant diseases, characterized in that... The plant disease mentioned is a plant disease caused by a pathogenic fungus, and the pathogenic fungus is: Sugarcane smut (… Sporisorium scitamineum Rice blast fungus ( Magnaporthe oryzae ), Neodatura spp. Neoscytalidium dimidiatum ), neatly arranged small sclerotia ( Sclerotium rolfsii ), Lithocarpus ( Calonectria ) and Ichthyophthirius multifiliis ( Nigrospora lacticoloni a).

9. The application of *Pseudomonas lundensis* and / or its fermentation broth as described in claim 1 in the control of plant diseases, characterized in that... The plant disease mentioned is a plant disease caused by pathogenic bacteria, and the pathogenic bacteria is Ralstonia solanacearum (Ralstonia solanacearum). Ralstonia solanacearum Xanthomonas aeruginosa (), Xanthomonas campestris pv. Campestris ), Citrus canker pathogen ( Xanthomonas citri subsp. citri ), Digib ( Dickeya ).

10. The application according to claim 9, characterized in that, The Digib ( Dickeya ) is the rice basal rot pathogen ( Dickeya oryzae ), potato soft rot pathogen ( Dickeya dadantii ), or taro soft rot bacteria ( Dickeya fangzhongdai ).

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