A strain of Duffyella gerundensis and its inoculants and applications

Abstract

The application belongs to the field of agricultural microorganism technology, and particularly relates to a strain Duffyella gerundensis and a microbial agent and application thereof. Duffyella gerundensis The strain is named CM21-1, is preserved in the China General Microbiological Culture Collection Center, and has a preservation number of CGMCC No. 36959. The 16S rDNA sequence of the strain is shown as SEQ ID NO: 1, can secrete an iron carrier, can effectively inhibit the growth of Fusarium pseudograminearum, and causes the hyphae of the Fusarium pseudograminearum to be broken or deformed. Fusarium pseudograminearum Pot experiment shows that the strain has a significant prevention and treatment effect on wheat foot rot, and has no adverse effect on the growth of wheat. The application provides a new biocontrol strain resource and technical scheme for green prevention and control of wheat foot rot.

Description

Technical Field

[0001] This invention belongs to the field of agricultural microbial technology, specifically relating to a strain Duffyella gerundensis Bacteria and their inoculants and their applications. Background Technology

[0002] Wheat stem rot ( Fusarium crown rot FCR is a soil-borne fungal disease caused by various Fusarium species infecting the base of wheat stems. Its main pathogen is *Fusarium pseudogranatum*. Fusarium pseudogramineum Fp).

[0003] The pathogen causing wheat stem rot has a wide host range, surviving for extended periods in soil and crop residues, and has a long infection window. When wheat seedlings are infected, the root sheath tissue undergoes browning and necrosis, leading to weak or dead seedlings. During the vegetative to reproductive growth stages, diseased plants produce fewer tillers, become stunted, and exhibit browning of the stem base cortex and vascular bundles, resulting in the typical "soy sauce stalk" symptom. This disease disrupts water and nutrient transport, causing premature water loss from the ear, resulting in withered white ears, lodging, or premature plant death, ultimately leading to a decrease in the number of grains per ear and a reduction in thousand-grain weight.

[0004] Currently, traditional control strategies for wheat stem rot mainly rely on the breeding of resistant varieties, agricultural interventions, and the application of chemical agents. However, existing wheat varieties generally lack stable resistance; agricultural control requires systematic adjustments to planting systems and strict implementation of refined management, which is difficult in practice; although chemical control is widely used in plant production, there is still a lack of highly effective specific agents for this disease, and long-term use of chemical agents easily leads to pesticide residues and the development of drug resistance in pathogens. Biological control, as an environmentally friendly emerging strategy, achieves ecological regulation of the disease by introducing antagonistic microorganisms and utilizing their competition, parasitism, and secretion of antimicrobial metabolites. It has good environmental compatibility and ecological sustainability, and shows significant potential in terms of control efficiency and safety, attracting widespread attention from agricultural researchers.

[0005] Rhizosphere microorganisms play a crucial role in the infection of soil-borne fungal diseases, and groups with disease-suppressing and disease-preventing functions can form a "protective barrier" around the plant root system. Therefore, isolating microorganisms from rhizosphere soil and developing their biocontrol functions has important application value for the green control of wheat stem rot. Summary of the Invention

[0006] The purpose of this invention is to provide a plant Duffyella gerundensis Application of *S. spp.* and its inoculant in the control of wheat stem rot. To achieve the above objective, this invention screened a biocontrol strain from wheat rhizosphere soil suspension. Duffyella from Girona CM21-1. Studies have shown that this fungus is significantly effective in controlling wheat stem rot caused by *Fusarium graminearum*.

[0007] On the one hand, the present invention provides a plant Duffyella gerundensis The Duffyella gerundensis Named Duffyella gerundensis CM21-1.

[0008] Specifically, the Duffyella gerundensis It was obtained by screening and separating from rhizosphere soil samples. Duffyella gerundensis The preservation information is as follows:

[0009] Strain name: CM21-1;

[0010] Category Name: Duffyella gerundensis ;

[0011] The collection center received the document on December 9, 2025.

[0012] Date of issuance of preservation certificate: December 29, 2025;

[0013] Preservation institution: China General Microbiological Culture Collection Center (CGMCC);

[0014] Accession number: CGMCC No.36959.

[0015] Address: No. 3, Courtyard 1, Beichen West Road, Chaoyang District, Beijing, Institute of Microbiology, Chinese Academy of Sciences.

[0016] Furthermore, the aforementioned Duffyella gerundensis The 16S rDNA sequence is shown in SEQ ID NO:1.

[0017] Furthermore, the aforementioned Duffyella gerundensis It can secrete siderophores.

[0018] Secondly, it also provides a product containing the invention described herein. Duffyella gerundensis Bacterial agents.

[0019] Thirdly, the present invention also provides the following: Duffyella gerundensis Or the application of fungal agents in the control of wheat stem base rot, wherein the wheat stem base rot is caused by Fusarium pseudograss. Fusarium pseudogramineum Induced 。

[0020] Fourthly, a method for preventing and controlling wheat stem rot is also provided, the method comprising applying the method described in this invention to wheat or the soil in which wheat grows. Duffyella gerundensis Or fungicides.

[0021] Furthermore, in the method, the Duffyella gerundensis By inhibiting Fusarium pseudograminearum Fusarium pseudogramineum To promote growth and prevent wheat stem rot.

[0022] Furthermore, in the method, the Duffyella gerundensis Can cause Fusarium pseudograss Fusarium pseudogramineum The hyphae break or deform.

[0023] Fifthly, a method for preparing a biocontrol agent is also provided, the method comprising culturing the biocontrol agent described in this invention. Duffyella gerundensis and collect the above Duffyella gerundensis The bacterial cells.

[0024] Sixthly, a composition for preventing and controlling wheat stem rot is also provided, said composition comprising the components described in this invention. Duffyella gerundensis Or fungicides, as well as agriculturally acceptable carriers or adjuvants.

[0025] Compared with the prior art, the technical solution provided by the present invention has at least the following beneficial effects or advantages:

[0026] This invention screened a wheat rhizosphere soil sample and obtained a plant with the preservation number CGMCC No. 36959. Duffyella gerundensis A new strain, CM21-1, inhibits the growth of *Fusarium graminearum* through a dual mechanism of contact inhibition and nutrient competition via secreted siderophores. Pot experiments showed that it contains... Duffyella gerundensis The bacterial agent can effectively control wheat stem rot caused by *Fusarium graminearum* (83.85% efficacy in potted plants), while the strain has no adverse effects on wheat growth and even has a certain growth-promoting effect. This invention provides a new bacterial strain resource and technical solution for the biological control of wheat stem rot. Attached Figure Description

[0027] Figure 1 for Duffyella gerundensis Colony morphology of CM21-1.

[0028] Figure 2 for Duffyella gerundensis Phylogenetic tree of CM21-1.

[0029] Figure 3 for Duffyella gerundensis The graph shows the evaluation results of the control effect of CM21-1 on wheat stem base rot. A represents the incidence rate, B represents the survival rate, C represents the biocontrol effect, and D represents the disease index. CK represents no inoculation. Duffyella gerundensis Treatments involving CM21-1 and the pathogen *Fusarium graminearum* WZ-8A: FP represents inoculation with pathogen WZ-8A only, while CM21-1+FP represents simultaneous inoculation. Duffyella gerundensis Treatment of CM21-1 and pathogen WZ-8A, with CM21-1 being inoculated only. Duffyella gerundensis Processing of CM21-1.

[0030] Figure 4In Embodiment 4 of the present invention Duffyella gerundensis Graph showing the inhibitory effect of CM21-1 on the pathogen *Fusarium graminearum* WZ-8A. A represents... Duffyella gerundensis A is a front view of a culture plate showing the confrontation between CM21-1 and pathogenic bacterium WZ-8A. B is a back view of the plate. C is a front view of the plate. Duffyella gerundensis Microscopic observation of hyphae at the boundary between CM21-1 and pathogenic fungus WZ-8A colonies. D is a microscopic observation of hyphae of pathogenic fungus control WZ-8A.

[0031] Figure 5 In Embodiment 4 of the present invention Duffyella gerundensis Results of CM21-1 siderophore production capacity test. A represents CM187-4-1, which does not produce siderophores; B represents... Duffyella gerundensis CM21-1, C represents the control culture on iron-deficient medium inoculated only with pathogens, and D represents the control culture on iron-deficient medium. Duffyella gerundensis Treatment of co-culturing CM21-1 and pathogenic bacteria WZ-8A. Detailed Implementation

[0032] The technical solution of the present invention will be described below with reference to the embodiments. However, the present invention is not limited to the following embodiments.

[0033] To enable those skilled in the art to better understand and implement the technical solutions of the present invention, the present invention will be further described below in conjunction with specific embodiments and accompanying drawings. However, the embodiments described are not intended to limit the present invention.

[0034] Unless otherwise specified, the test methods and detection methods described in the following embodiments are conventional methods; unless otherwise specified, the reagents and materials are commercially available.

[0035] Example 1

[0036] This embodiment is obtained through screening. Duffyella gerundensis CM21-1 strain.

[0037] 1.1 Culture medium

[0038] Tryptone-Soybean Broth Medium (TSB): 15g tryptone, 5g soybean peptone, 5g sodium chloride, distilled water to a final volume of 1000mL, pH 7.0~7.4.

[0039] Tryptone-Soybean Agar Medium (TSA medium): 15g tryptone, 5g soybean peptone, 5g sodium chloride, 20g agar, distilled water to a final volume of 1000mL, pH 7.0~7.4.

[0040] Potato glucose agar medium (PDA medium): Cut 200g of peeled potatoes into small pieces and boil for 20 minutes. Filter the liquid through three layers of gauze and collect the filtrate. Add 20g of glucose, 20g of agar powder, and distilled water to a final volume of 1000mL. The pH value is the natural value.

[0041] 1.2 Sample Collection and Processing

[0042] Rhizosphere soil samples were collected from the crop specimen area of ​​Northwest A&F University. This area is a dedicated nursery for wheat stem rot caused by artificial inoculation with *Fusarium graminearum*, and wheat stem rot has been prevalent for several years. Ten wheat varieties were originally planted at this site. Five wheat plants of each variety were randomly selected for sampling. During sampling, the entire wheat plant was dug up with a shovel, and large clumps of soil attached to the roots were removed by vigorous shaking. The above-ground stems were then cut off with sterilized scissors, and the remaining soil-bearing roots were placed in sealed bags, numbered, and placed in a low-temperature storage box before being quickly transported back to the laboratory. First, the wheat sample roots were rinsed with sterile water to remove loosely attached soil. Then, the wheat roots were cut off with sterilized scissors and transferred to 50 mL centrifuge tubes. 25 mL of sterile phosphate buffer was added to the tubes, and the samples were washed at 180 rpm for 15 minutes at room temperature on a shaker. This washing process was repeated three times. The resulting soil suspension was then centrifuged at 4654×g for 5 minutes, and the precipitate was collected and defined as a rhizosphere soil sample, which was then stored at 4℃ for later use.

[0043] 1.3 Isolation and Purification of Bacteria

[0044] After mixing the rhizosphere soil samples in equal proportions, microbial isolation was performed using the dilution-spreading method. Ten samples were prepared separately. -1 10 -2 10 -3 10 -4 Four gradients of soil suspensions were evenly spread onto TSA plates and incubated in the dark at 26°C for 2–4 days. After colonies grew, they were initially distinguished based on size, shape, color, transparency, and surface texture. Single colonies with significant morphological differences were selected and transferred to fresh TSA plates for purification. The purified strains were then stored at -80°C using 25% glycerol. Before subsequent experiments, the stored strains were inoculated onto TSA plates for activation and later use.

[0045] 1.4 Screening of biocontrol bacteria

[0046] The tested pathogen was *Fusarium graminearum* WZ-8A, provided by Professor Li Honglian of the College of Plant Protection, Henan Agricultural University. This strain has been published in the China General Microbiological Culture Collection Center, accession number: CGMCC No. 28094.

[0047] Shaking inoculum: Pick a single colony of bacteria obtained from purification step 1.3 and inoculate it into TSB liquid medium. Incubate with shaking at 28°C and 180 rpm for 12 hours. After the culture becomes turbid, centrifuge the culture at 4°C and 4654 × g for 5 minutes. Discard the supernatant and collect the bacterial precipitate. Resuspend the bacterial cells in 50 μM PBS buffer (pH 7.0) and measure their OD... 600 Adjust the value to 1.0 to obtain the required bacterial suspension for later use.

[0048] Preparation of pathogen inoculum: After cooking millet, it was placed in an Erlenmeyer flask and sterilized at 121℃ for 30 minutes to prepare millet culture medium. The activated Fusarium graminearum WZ-8A pathogen was inoculated into the millet culture medium and cultured at 26℃ for 7 days. After the culture was completed, it was dried and ground in a clean bench to obtain the pathogen powder inoculum for later use.

[0049] Initial screening using pot experiments:

[0050] After disinfecting the seeds of the wheat variety Bainong 207, which is susceptible to stem base rot, sow them into 120g of sterilized soil (12 seeds per pot), and then cover them with 20g of sterilized soil. There were two treatments: one was inoculated with each strain and Fusarium graminearum WZ-8A pathogen (B+FP), and the other was inoculated with only Fusarium graminearum WZ-8A pathogen (FP). There were no replicates between the treatments.

[0051] For the B+FP treatment, 25 mL of each treatment's bacterial suspension was inoculated into the soil around the seeds. Then, 0.5 g of pathogenic fungal powder and 0.8 g of wheat bran were evenly inoculated onto the soil surface. Finally, 20 g of sterilized soil was placed on top of the pathogenic fungal powder and wheat bran. Additionally, the treatment (FP) inoculated only with *Fusarium graminearum* WZ-8A was used as a control, with an equal volume of sterile PBS buffer instead of the bacterial suspension; all other procedures were the same. Disease severity was assessed on day 21 from sowing, and the plant disease index was calculated. Strains corresponding to treatments with 8 or more seedlings after inoculation and disease indices ranging from 0 to 20.00 were selected as potential biocontrol bacteria.

[0052] Disease Index (DI) = 100 × ∑ (value of each disease level × number of plants at each disease level) / (total number of plants × 9)

[0053] The initial screening results of the biocontrol bacteria showed that the B+FP treatment inoculated with CM21-1 bacterial suspension had a germination rate of more than 8 strains and a disease index of 9.72. Therefore, bacteria CM21-1 was selected as the subject of subsequent research.

[0054] Example 2

[0055] This example demonstrates the identification of the bacterial strain CM21-1 obtained through screening.

[0056] 2.1 Morphological identification of bacteria CM21-1

[0057] The bacteria CM21-1 screened in Example 1 were streaked onto TSA medium for activation. Single colonies of the activated bacteria were then picked and streaked onto TSA plates and incubated at 28°C for 48 hours. Morphology was then observed. Results are as follows: Figure 1 As shown, a single colony of bacteria CM21-1 is yellow with smooth edges, a smooth overall surface, a slightly raised center, and a creamy texture.

[0058] 2.2 Molecular biological identification of bacteria CM21-1

[0059] The preserved bacterial suspension of CM21-1 was inoculated into TSB liquid medium and cultured at 28°C with shaking at 180 rpm for 12 h, using the bacterial suspension of CM21-1 as a template. PCR amplification was performed using the universal primers 27F and 1492R for bacterial 16S rDNA. The sequence information of 27F and 1492R is as follows:

[0060] 27F (SEQ ID NO:2): 5'-AGAGTTTGATCCTGGCTCAG-3',

[0061] 1492R (SEQ ID NO:3): 5'-TACGGCTACCTTGTTACGACTT-3'.

[0062] The PCR reaction system (20 μL) is shown in Table 1.

[0063] Table 1 PCR reaction system

[0064]

[0065] PCR reaction conditions: 95℃ pre-denaturation for 10 min; 95℃ denaturation for 20 s, 1 cycle; 56℃ annealing for 30 s; 72℃ extension for 1 min, 36 cycles; finally, 72℃ extension for 5 min.

[0066] The PCR product was analyzed by 1% agarose gel electrophoresis. Compared with the DL 2000bp marker, the fragment size was approximately 1500bp, which was consistent with expectations. The PCR product was sent to Sangon Biotech (Shanghai) Co., Ltd. for sequencing. The 16S rDNA sequencing results of bacteria CM21-1 are shown in SEQ ID NO:1, totaling 1440bp. The specific sequence is as follows:

[0067]

[0068] The 16S rDNA gene sequence of bacteria CM21-1 was compared with BLAST in the NCBI nucleic acid database, and a phylogenetic tree was constructed using the Neighbor-Joining method in Mega11.0 software.

[0069] The 16S rRNA gene sequence of bacteria CM21-1 and Duffyella gerundensis The sequence similarity of the type strain was as high as 99.86%, far exceeding the species-level threshold (usually ≥99.5%). The phylogenetic tree of bacteria CM21-1 is as follows: Figure 2 As shown, bacterial CM21-1 exhibited 100% self-spread support compared to the reference strain. Duffyella gerundensis Therefore, based on morphological and molecular biological identification, bacteria CM21-1 was identified as... Duffyella gerundensis, The strain is named as follows: Duffyella gerundensis CM21-1.

[0070] Example 3

[0071] This embodiment is Duffyella gerundensis Evaluation of the biocontrol effect of CM21-1 on wheat stem base rot.

[0072] Preparation of pathogen inoculum: After cooking millet, it was placed in an Erlenmeyer flask and sterilized at 121℃ for 30 minutes to prepare millet culture medium. The activated Fusarium graminearum WZ-8A pathogen was inoculated into the millet culture medium and cultured at 26℃ for 7 days. After the culture was completed, it was dried and ground in a clean bench to obtain the pathogen powder inoculum for later use.

[0073] Duffyella gerundensis Preparation of CM21-1 bacterial suspension: The method is the same as that used in the screening of biocontrol bacteria in section 1.4.

[0074] Pot experiment to verify the control efficacy:

[0075] After disinfecting the seeds of Bainong 207 wheat, sow 12 seeds per pot into 120g of sterilized soil, cover with 20g of sterilized soil, and then inoculate with 25mL of [unspecified substance]. Duffyella gerundensis Apply CM21-1 bacterial suspension around the seeds, and then evenly inoculate the soil surface with 0.5g of pathogen powder and 0.8g of wheat bran, finally covering with 20g of sterilized soil. This experiment included four treatment groups; the blank control group (CK) was treated with sterile PBS instead of... Duffyella gerundensis CM21-1 bacterial suspension without inoculation with pathogens; experimental group (CM21-1) inoculated with... Duffyella gerundensis CM21-1 bacterial suspension without inoculation with pathogens; experimental group (CM21-1+FP), inoculated with pathogens. Duffyella gerundensis CM21-1 bacterial suspension and pathogens; pathogen control group (FP), replaced by sterile PBS. Duffyella gerundensis CM21-1 bacterial suspension was inoculated with only the pathogen. Each treatment was replicated in 3 pots.

[0076] The incidence and survival rates of plants in the experimental group (CM21-1+FP) and the pathogen control group (FP) were recorded every two days starting from the 5th day after sowing. On the 21st day, the disease severity was determined, and the plant disease index and control effect were calculated.

[0077] The blank control group (CK) and the experimental group (CM21-1) had their whole plants collected on day 21. They were gently rinsed with running water to remove all soil particles, and then allowed to air dry in a cool place until there was no obvious moisture on the surface. The plant height was measured, and the plant was precisely divided into the above-ground part and the underground root system using tools. The fresh weight of each part was measured.

[0078] Disease Index (DI) = 100 × ∑ (value of each disease level × number of plants at each disease level) / (total number of plants × 9)

[0079] Prevention and control efficacy (%) = (Disease index of control group - Disease index of treatment group) / Disease index of control group × 100

[0080] Depend on Figure 3 China A and Figure 3 As shown in the B-group, compared with the FP treatment group, the onset time in the CM21-1+FP treatment group was delayed to day 7, and the incidence rate remained low throughout, indicating that... Duffyella gerundensis CM21-1 significantly delayed the occurrence of wheat stem rot and maintained a 100% plant survival rate. Figure 3 C and Figure 3 As shown in the data, on day 21, the plant growth status of the CM21-1+FP treatment group was significantly better than that of the FP treatment group, and its disease index was significantly lower than that of the FP treatment group.

[0081] Table 2 Duffyella gerundensis CM21-1's effect on wheat stem base rot control

[0082]

[0083] Table 2 shows that the relative control efficacy of the CM21-1+FP treatment group reached 83.85%. These results indicate... Duffyella from Girona CM21-1 effectively controlled the development of wheat stem rot and significantly reduced plant mortality. This indicates... Duffyella gerundensis CM21-1 has a preventive effect against wheat stem rot.

[0084] Plant growth compatibility assessment:

[0085] The results of plant height, aboveground fresh weight, and underground fresh weight measurements of the blank control group (CK) and the experimental group (CM21-1) are shown in Table 3. Compared with CK, after... Duffyella gerundensis Wheat treated with CM21-1 showed slightly higher plant height, aboveground fresh weight, and underground fresh weight than the control group, but the differences were not statistically significant. This indicates that... Duffyella gerundensis CM21-1 has no adverse effects on wheat growth and shows certain positive growth potential under experimental conditions.

[0086] Table 3 Duffyella gerundensis Effects of CM21-1 on wheat growth indicators

[0087]

[0088] Example 4

[0089] This embodiment is for exploration. Duffyella gerundensis The antibacterial mechanism of CM21-1 against Fusarium graminearum.

[0090] 4.1 Duffyella gerundensis Effects of CM21-1 on the morphology of Fusarium pseudograss

[0091] Will Duffyella gerundensis Strain CM21-1 was inoculated into TSB liquid medium and cultured by shaking, using the same shaking method as in the screening of biocontrol bacteria in section 1.4. After activation, the pathogen (Fusarium graminearum WZ-8A) was inoculated into the center of a PDA plate, with symmetrical inoculations approximately 2 cm away from the pathogen's mycelial cake. Duffyella gerundensis CM21-1 bacterial suspension (3 μL), with the treatment of inoculation with pathogen and sterile TSB medium as controls, was incubated at 26℃ for 7 days. The growth of the strain was then observed, and the results are as follows: Figure 4 As shown, by Figure 4 From A and B, we can see that, with Duffyella gerundensis In the contact area of ​​strain CM21-1, the colonies of pathogen WZ-8A were sparse and yellowed to the naked eye; further microscopic observation revealed the following results. Figure 4 As shown in C and D, there are Duffyella gerundensis On the pathogenic agar plate, the hyphae of strain CM21-1 exhibited abnormal morphology, including breakage, deformation, and swelling, while... Duffyella gerundensis The mycelial morphology of the control area of ​​strain CM21-1 was normal, indicating that... Duffyella gerundensis The CM21-1 strain may effectively inhibit the growth of Fusarium pseudograss through contact inhibition.

[0092] 4.2 Duffyella gerundensis Determination of the iron-producing capacity of CM21-1

[0093] Ferrophilic assay medium (CAS solid medium): Modified CAS liquid medium / ferophilic assay liquid medium (kit) produced by Beijing Coollab Technology Co., Ltd. was used. 121g of basal medium and 15g of agar were added, and the volume was adjusted to 800mL with purified water. The solution was dissolved by stirring with a glass rod. The medium was sterilized at 115℃ for 20min, cooled to 50~60℃, and 100mL of 10× buffer solution (preheated to 60℃) and CAS assay solution were slowly added to the basal medium. Plates were then prepared for use.

[0094] Iron-deficient King's B solid medium: 20g tryptone, 1.5g dipotassium hydrogen phosphate, 1.5g magnesium sulfate heptahydrate, 10mL glycerol, 15g agar, add pure water to a final volume of 1L.

[0095] Iron-deficient King's B liquid medium: 20g tryptone, 1.5g dipotassium hydrogen phosphate, 1.5g magnesium sulfate heptahydrate, 10mL glycerol, add pure water to a final volume of 1L.

[0096] Iron production capacity determination:

[0097] Will Duffyella gerundensis CM21-1 strain was inoculated into iron-deficient King's B liquid medium and shaken. 3 μL of the bacterial culture was dropped 2 cm from the center of a CAS plate. Three replicates were performed. An equal volume of iron-deficient King's B liquid medium was used as the control group. Simultaneously, a non-side-producing strain, *Buchuriae*, was also included. Buttiauxella gaviniae CM187-4-1 (abbreviated as CM187-4-1) served as a control for non-side-producing strains. After incubation at 28℃ for 3 days, the siderophore-producing capacity of each treatment was tested, and the results are as follows: Figure 5 As shown in Figures A and B, in the culture medium Duffyella gerundensis The CM21-1 colony showed an orange-red halo, while CM187-4-1 and CK colonies did not, indicating that... Duffyella gerundensis CM21-1 has the ability to secrete siderophores.

[0098] Co-culture in iron-deficient medium:

[0099] After activation, the pathogen (Fusarium graminearum WZ-8A) was inoculated into the center of an iron-deficient King's B agar plate. Duffyella gerundensis The CM21-1 strain was inoculated into iron-deficient King's B liquid medium and cultured by shaking. 3 μL of the medium was pipetted... Duffyella gerundensis CM21-1 bacterial droplets were placed 2 cm away from the pathogen, with four replicates. A control group (pathogen-only inoculation) was used. The cultures were incubated at 28°C for 7 days. The siderophore production capacity of each treatment was then tested. Results are as follows: Figure 5 C and Figure 5 As shown in D, Duffyella gerundensis A distinct inhibition zone appeared in the CM21-1 treatment area, accompanied by an orange-red halo, indicating that... Duffyella from GironaCM21-1 may inhibit the growth of Fusarium graminearum by efficiently chelating trace amounts of iron in the environment through the secretion of siderophores.

[0100] As described above, the basic principles, main features, and advantages of the present invention have been well described. The above embodiments and specifications are merely descriptions of preferred embodiments of the present invention, and the present invention is not limited to the above embodiments. Various changes and improvements made to the technical solutions of the present invention by those skilled in the art without departing from the spirit and scope of the present invention should fall within the protection scope defined by the present invention.

Claims

1. A plant Duffyella gerundensis Its characteristics are, The Duffyella gerundensis Named Duffyella gerundensis CM21-1 is deposited at the China General Microbiological Culture Collection Center (CGMCC) with accession number CGMCC No. 36959.

2. As described in claim 1 Duffyella gerundensis, Characterized by, the Duffyella from Girona The 16S rDNA sequence is shown in SEQ ID NO:

1.

3. As described in claim 1 Duffyella gerundensis, Characterized by, the Duffyella from Girona It can secrete siderophores.

4. Containing the contents of claim 1 Duffyella gerundensis Bacterial agents.

5. The claim 1 Duffyella gerundensis Or the application of the fungal agent according to claim 4 in the prevention and control of wheat stem base rot, characterized in that, The wheat stem base rot is caused by Fusarium pseudograminearum (… Fusarium pseudograsses ) induce 。 6. A method for preventing and controlling wheat stem base rot, characterized in that, Including the application of the method described in claim 1 to wheat or the soil in which wheat grows. Duffyella gerundensis Or the fungal agent according to claim 4, wherein the wheat stem base rot is caused by Fusarium pseudograss (… Fusarium pseudogramineum (Induced by) 7. The method according to claim 6, characterized in that, The Duffyella gerundensis By inhibiting Fusarium pseudograss ( Fusarium pseudogramineum To promote the growth of wheat and prevent wheat stem rot.

8. The method according to claim 6, characterized in that, The Duffyella gerundensis Can cause Fusarium pseudograss ( Fusarium pseudogramineum The hyphae of the fungus break or deform.

9. A method for preparing a biocontrol agent, characterized in that, Including the cultivation of the method described in claim 1 Duffyella from Girona and collect Duffyella gerundensis The bacterial cells.

10. A composition for controlling wheat stem base rot, characterized in that, Includes the claims 1 Duffyella gerundensis Or the microbial agent as described in claim 4, and an agriculturally acceptable carrier or adjuvant.

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