Chryseobacterium sp. And application thereof

Abstract

The invention relates to the technical field of environmental microorganisms, in particular to Chryseobacterium Chry.R1 and application of the Chryseobacterium Chry.R1, and the preservation number of the Chryseobacterium Chry.R1 is GDMCC (China General Microbiological Culture Collection Center) No.63568. The Chryseobacterium Chry.R1 has the effects of fixing nitrogen, inhibiting fusarium graminearum and promoting plant growth. The Chryseobacterium Chry.R1 disclosed by the invention can be used for promoting the absorption and utilization of nitrogen elements in a plant growth process, inhibiting the growth of fusarium graminearum and promoting the growth of plants, and a new microbial strain resource is provided for realizing reduction and synergism of chemical fertilizers in agricultural production.

Description

Technical Field

[0001] The present invention relates to the field of environmental microbiology technology, and particularly to Chryseobacterium and its applications. Background Art

[0002] With the growth of the world's population and the reduction of arable land, food security has become a hot topic of concern. Over the past 40-odd years, China has achieved stable increases in national grain production by applying chemical fertilizers and pesticides. However, the excessive application of chemical fertilizers and pesticides has brought a series of environmental impacts. The excessive application of chemical fertilizers easily leads to the destruction of soil structure, the loss of soil nutrients, soil compaction, and secondary salinization of the soil environment; the unreasonable application of pesticides will bring problems such as excessive pesticide residues in agricultural products and environmental pollution. Plant growth-promoting rhizobacteria refer to beneficial microorganisms that can colonize the rhizosphere of plants and have a promoting effect on plant growth, development, and stress resistance. Therefore, the development and utilization of plant growth-promoting rhizobacteria resources can reduce the application amount of chemical fertilizers, improve the utilization rate of chemical fertilizers, partially replace the application of pesticides, and alleviate the environmental impacts brought by chemical fertilizers and pesticides.

[0003] Fusarium graminearum can infect cereal crops such as wheat and barley, causing a serious fungal disease - wheat head blight, thus severely damaging the yield and quality of wheat. Wheat head blight causes yield losses by reducing grain production, seed germination rate, grain weight, number of grains per head, etc. In addition, various mycotoxins, such as trichothecenes and zearalenone, will be produced in the diseased wheat grains, posing a great harm to the health of humans and animals and bringing serious food safety problems. Head blight has become one of the main diseases in wheat production. Therefore, it is urgent to control wheat head blight.

[0004] At present, there are mainly three categories of methods for controlling wheat head blight: agricultural control, chemical control, and biological control. Breeding disease-resistant varieties is an important means of agricultural control and one of the most economical and effective ways. However, no wheat varieties immune to head blight have been found yet. Using fungicides for chemical control is currently the most direct and effective measure. However, the long-term application of chemical agents will lead to the development of drug resistance in pathogenic bacteria, increasing the difficulty of control. In addition, the application of a large amount of chemical agents will also bring problems such as agricultural non-point source pollution and food safety. Biological control is an effective control means that uses the antagonistic relationship between biological species to inhibit the growth of pathogenic bacteria, and has the advantages of being environmentally friendly and not generating drug resistance to pathogenic bacteria, and has received extensive attention.

[0005] Currently reported strains with biocontrol and growth promotion functions include Bacillus sp., Paenibacillus sp., Burkholderia sp., Pseudomonas sp., Pantoea sp., Rhizobium sp., etc., but there is no research on Chryseobacterium in terms of growth promotion and biocontrol.

[0006] CN 115637238 A discloses a Chryseobacterium sp. with the preservation number of CGMCC No. 25365 and the strain number of CP3; this Chryseobacterium has the characteristics of promoting growth and degrading chlorpyrifos, can be prepared into a microbial agent, can enhance the degradation of residual chlorpyrifos in rice, and promote the growth of rice, and is applied to the remediation of chlorpyrifos residue pollution in the rice planting system; this Chryseobacterium belongs to plant endophytes, can colonize in rice for a long time, reduce pesticide residues in crops without affecting the quality of agricultural products, ensure the quality and safety of agricultural products, and achieve green and safe production.

[0007] CN 111733113 B discloses a COD-degrading bacterial strain and its application. The COD-degrading bacterial strain is identified as Chryseobacterium indologenes with the preservation number of CCTCC NO: M 2018651. The Chryseobacterium indologenes CI-B4 is salt-tolerant, cold-tolerant, and has a wide temperature application range (5 - 40°C); it has the ability to efficiently degrade organic pollutants in wastewater, can improve the effluent quality of organic wastewater; after enlarged cultivation, it can be applied to the biochemical treatment of livestock and poultry breeding wastewater, industrial organic wastewater, river black and smelly water bodies, kitchen waste anaerobic digestion biogas slurry, etc., and has high application value; when used to treat organic wastewater, it has high treatment efficiency, good economic benefits, convenient operation, and no pollution.

[0008] CN 102433277 B discloses a Chryseobacterium for removing phosphorus from sewage at low temperature and a method for its isolation and culture. The Chryseobacterium sp. deep yellow polyphosphate-accumulating CGMCC No. 5282 for removing phosphorus from sewage at low temperature has the ability to remove phosphorus from sewage under low-temperature aerobic conditions. The experimental results of this invention show that: although significantly inhibited by the low-temperature environment, adding the Chryseobacterium sp. deep yellow polyphosphate-accumulating CGMCC No. 5282 for removing phosphorus from sewage at low temperature of this invention has an obvious strengthening effect on phosphorus removal at low temperature, especially under the condition of 8 - 12 °C. The phosphorus removal rate is increased by 10%, which is better than the effluent standard of Grade A (when the water temperature ≤ 12 °C, the control index of the Grade A standard is 0.5 mg / L). Summary of the Invention

[0009] The inventor of the present invention unexpectedly isolated a new Chryseobacterium from a soybean rhizosphere soil sample, sequenced it and named it Chry.R1. This Chryseobacterium Chry.R1 has the functions of nitrogen fixation, inhibiting Fusarium graminearum and promoting plant growth. Thus, the present invention was completed.

[0010] In the first aspect, the present invention provides a Chryseobacterium, and the sequence of the 16S rDNA of the Chryseobacterium is as shown in SEQ ID NO: 1.

[0011] In the second aspect, the present invention provides a bacterial agent comprising the Chryseobacterium described in the first aspect.

[0012] In the third aspect, the present invention provides the use of the Chryseobacterium described in the first aspect or the bacterial agent described in the second aspect for nitrogen fixation and / or inhibiting Fusarium graminearum during plant growth.

[0013] In the fourth aspect, the present invention provides the use of the Chryseobacterium described in the first aspect or the bacterial agent described in the second aspect for promoting plant growth.

[0014] In the fifth aspect, the present invention provides a method for culturing the Chryseobacterium described in the first aspect. Inoculate the Chryseobacterium in a nutrient broth peptone medium with a pH of 7.4 - 7.6 and a culture temperature of 28 °C.

[0015] The present invention has the following beneficial effects:

[0016] The Chryseobacterium Chry.R1 of the present invention has the functions of nitrogen fixation, inhibiting Fusarium graminearum, and promoting plant growth. Applying Chry.R1 of the present invention can promote the absorption and utilization of nitrogen elements during plant growth, inhibit the growth of Fusarium graminearum, and promote plant growth, providing a new microbial strain resource for realizing the reduction of chemical fertilizers and increasing efficiency in agricultural production, and enriching our available microbial resources. Brief Description of the Drawings

[0017] In order to more clearly illustrate the technical solutions in the specific embodiments of the present invention, the drawings in the specific embodiments will be briefly introduced below.

[0018] Figure 1 Shows the phylogenetic tree of the Chry.R1 sequence and the sequences of its related strains.

[0019] Figure 2 Shows a photo of Chry.R1 growing on a beef extract peptone solid medium plate.

[0020] Figure 3 Shows an image of Chry.R1 under a microscope.

[0021] Figure 4 Shows the growth status of Chry.R1 on Ashby nitrogen-free medium.

[0022] Figure 5 Shows the inhibitory effect of Chry.R1 on Fusarium graminearum.

[0023] Figure 6 Shows the growth promotion effect of Chry.R1 on soybeans.

[0024] Figure 7 Shows the growth promotion effect of Chry.R1 on foxtail millet. Detailed Description of the Embodiments

[0025] In the following, the present invention will be described in detail. It should be understood that the following description is only illustrative of the present invention and is not intended to limit the scope of the present invention. The protection scope of the present invention is subject to the appended claims. And those skilled in the art understand that the technical solutions of the present invention can be modified without departing from the spirit and gist of the present invention. If not specifically specified, the technical means used in the embodiments are conventional means well-known to those skilled in the art.

[0026] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the subject matter of the present invention belongs. Before describing the present invention in detail, the following definitions are provided to better understand the present invention.

[0027] In this text, the term "bacterial agent" refers to the general name of liquid or solid products with microbial populations after artificial inoculation and cultivation. That is, the product obtained by growing and / or amplifying microorganisms, which can be a biologically pure culture of microorganisms or can contain a certain amount of culture medium, metabolites or other components produced during the cultivation process. The term "bacterial agent" also includes subcultures obtained by subculturing microorganisms, which can be a culture of a certain generation or a mixture of several generations.

[0028] As mentioned above, the inventors of the present invention unexpectedly isolated a new Chryseobacterium from a soybean rhizosphere soil sample, sequenced it and named it Chry.R1. This Chryseobacterium Chry.R1 has the functions of nitrogen fixation, inhibiting Fusarium graminearum and promoting plant growth, and the biological control of wheat scab can be achieved by using Chryseobacterium Chry.R1.

[0029] In a first aspect, the present invention provides a Chryseobacterium Chry.R1, the preservation number of the Chryseobacterium Chry.R1 is GDMCC No. 63568, and the sequence of the 16S rDNA of the Chryseobacterium Chry.R1 is as shown in SEQ ID NO: 1.

[0030] In a second aspect, the present invention provides a bacterial agent comprising the Chryseobacterium Chry.R1 described in the first aspect, and the bacterial agent can be in liquid, powder or granular form.

[0031] In a third aspect, the present invention provides the use of the Chryseobacterium Chry.R1 described in the first aspect or the bacterial agent described in the second aspect for nitrogen fixation and / or inhibiting Fusarium graminearum during the plant growth process. In a preferred embodiment, the plant is soybean or millet. In an embodiment, the use is achieved by the following steps: (1) fermenting the Chryseobacterium Chry.R1 described in the first aspect or the bacterial agent described in the second aspect (for example, after activating the strain Chry.R1, inoculating it into a beef extract peptone medium and performing shaking fermentation); (2) using the fermented Chryseobacterium Chry.R1 or bacterial agent obtained in step (1) to perform root irrigation treatment during the sowing period and / or seedling stage (such as soybean) of the plant, or during the emergence period and / or jointing stage (such as millet).

[0032] In a fourth aspect, the present invention provides the use of Chryseobacterium Chry.R1 described in the first aspect or the bacterial agent described in the second aspect in promoting plant growth. In a preferred embodiment, the plant is soybean or millet. The promotion of plant growth can be manifested as an increase in the plant height, and / or root length, and / or above-ground fresh weight and / or below-ground fresh weight. In one embodiment, the use is achieved by the following steps: (1) fermenting Chryseobacterium Chry.R1 described in the first aspect or the bacterial agent described in the second aspect (for example, after activating strain Chry.R1, inoculating it into a peptone beef extract medium and performing shaking fermentation); (2) using the fermented Chryseobacterium Chry.R1 or bacterial agent obtained in step (1) to perform root irrigation treatment during the sowing period and / or seedling stage of the plant (such as soybean), or during the emergence stage and / or jointing stage (such as millet).

[0033] In a fifth aspect, the present invention provides a method for culturing Chryseobacterium Chry.R1 described in the first aspect. The Chryseobacterium Chry.R1 is inoculated into a peptone beef extract medium with a pH of 7.4 - 7.6 and a culture temperature of 28°C. The components of the peptone beef extract medium include 10 g / L peptone, 3 g / L beef extract, and 5 g / L sodium chloride.

[0034] Examples

[0035] The following will clearly and completely describe the concept and technical effects generated by the present invention in combination with examples and drawings to fully understand the purpose, features, and effects of the present invention. Obviously, the described examples are only a part of the examples of the present invention, rather than all the examples. Based on the examples of the present invention, other examples obtained by those skilled in the art without creative efforts all fall within the scope of protection of the present invention.

[0036] Example 1: Isolation of Chry.R1

[0037] Collect soybean rhizosphere soil samples. Pour the rhizosphere soil samples into a mortar, add 2 - 3 mL of sterile water, and grind the rhizosphere soil samples into a powdery state to obtain a grinding liquid. Dilute the grinding liquid with sterile water to gradient concentrations of 10 2 to 10 5 . Coat the gradient dilution solutions onto a peptone beef extract solid medium respectively, and at the same time coat sterile water without bacterial solution as a blank control. The components of the peptone beef extract medium include 10 g / L peptone, 3 g / L beef extract, and 5 g / L sodium chloride. After coating, incubate in an inverted position at 28°C for 48 - 72 hours. Pick single colonies and amplify them in a liquid peptone beef extract medium, and then perform repeated streak amplification to purify and obtain various strains, including strain Chry.R1.

[0038] Example 2: Identification of Chry.R1 and determination of its evolutionary status

[0039] Sequencing was performed on the 16S rDNA gene of the monoclonal strain obtained in Example 1, and the specific sequence of Chry.R1 obtained by sequencing is as follows: ACCCGGCCTGCGGAGTCTACACA TGCAAGCCGAGCGGTATAGATCTTTCGGGATCTAGAGAGCGGCGCACGGGTGCGGAACACGTGTGCAACCTACCTTTATCAGGGGGATAGCCTTTCGAAAGGAAGATTAATACCCCATAATATATTAGATGGCATCATTTGATATTGAAAACTCCGGTGGATAGAGATGGGCACGCGCAAGATTAGATAGTTGGTGAGGTAACGGCTCACCAAGTCAATGATCTTTAGGGGGCCTGAGAGGGTGATCCCCCACACTGGTACTGAGACACGGACCAGACTCCTACGGGAGGCAGCAGTGAGGAATATTGGACAATGGGTGAGAGCCTGATCCAGCCATCCCCGCGTGAAGGATGACGACCCTATTGGGATGTAAACTTCTTTTGTATAAGGATAAACCTACCCTCGTGAGGGTAGCTGAAGGTACTATACGAATAAGCACCGGCTAACTCCGTGCCAGCAGCCGCGGTAATACGGAGGGTGCAAGCGTTATCCGGATTTATTGGGTTTAAAGGGTCCGTAGGCGGACTCGTAAGTCAGTGGTGAAATCTCATAGCTTAACTATGAAACTGCCATTGATACTGCGGGTCTTGAGTAAGGTAGAGGTAGCTGGAATAAGTAGTGTAGCGGTGAAATGCATAGATATTACTTAGAACACCAATTGCGAAGGCAGGTTACCATGTCTTAACTGACGCTGATGGACGAAAGCGTGGGGAGCGAACAGGATTAGATACCCTGGTAGTCCACGCCGTAAACGATGCTAACTCGTTTTTTGGGTTTTCGGATTCAGAGACTAAGCGAAAGTGATAAGTTAGCCACCTGGGGAGTACGAACGCAAGTTTGAAACTCAAAGGAATTGACGGGGGCCCGCACAAGCGGTGGATTATGTGGGTTTAATTCGATGATACGCGAGGAACCTTACCAAGGCTTAAATGGGAAATGACAGGCTTAGAAATAAGCTTTTCTTCGGACATTTTTCAAGGTGCTGCATGGTTGTCGTCACCTCGGGCCGGGAGGTGATAGGTTAAGTCCCTGCAACGGACCGCAACCCCTTGTCACTAGGTGCCAACATTCAGTTGGGGACTCTAGTGAGACTGCCTACGCAAGTAGAGAGGAAGGTGGGGATGACGTCAAATCATCACGGCCCTTACGCCTTGGGCCACACACGTAATACAATGGCCAGTACAGAGGGCTGCTACCAGGCGACTGGATGCTAATCTCGAAAGCTGGTCTCAGTTCGGATTGGAGTCTGCAACTCGACTCTATGAAGCTGGAATCGCTAGTAATCGCGCATCAGCCATGGCGCGGTGAATACGTTCCCGGGCCTTGTACACACCGCCCGTCAAGCCATGGAAGTCTGGGGTACCTGAAGTCGGTGACCGTAACAGGAGCTGCCTAGGTAAACAGTTTTGCC(SEQ ID NO:1).

[0040] The approximately 1.4 Kb sequence of Chry.R1, which is nearly the full length of 16S rDNA obtained by sequencing, was aligned in the 16S rDNA gene database of EzBioCloud. The alignment results showed that the two strains with the highest homology to the 16S rDNA gene of Chry.R1 in the database were Chryseobacterium ginsenosidimutans THG 15(T) (accession number: GU138380) and Chryseobacterium oncorhynchi 701B-08(T) (accession number: FN674441), with similarity of 96.16% and 95.71% respectively (both less than the new strain determination standard of 98.65%). The phylogenetic tree of Chry.R1 and its related strains was constructed by the neighbor-joining method using MAGA, and the results are as Figure 1 shown. Based on the 16S rDNA sequence, it can be preliminarily determined that Chry.R1 is a new bacterial species belonging to the genus Chryseobacterium.

[0041] Furthermore, the whole genome of the monoclonal strain obtained in Example 1 was sequenced, and the average nucleotide identity (ANI) analysis was performed between the sequenced Chry.R1 sequence and its related bacteria. As shown in Table 1, the ANI values of strain Chry.R1 with Chryseobacterium sediminis MT-174 and Chryseobacterium soli DSM 19298 were the highest, 79.98% and 79.95% respectively (both less than the new strain determination standard of 95%). Therefore, based on the sequence of the whole genome of Chry.R1, it can be determined that Chry.R1 is a new bacterial species belonging to the genus Chryseobacterium.

[0042] Table 1: ANI value analysis of Chry.R1 and other related bacteria in the genus Chryseobacterium

[0043] Related bacteria ANI (%) Chryseobacterium sediminis MT-174 79.98 Chryseobacterium soli DSM 19298 79.95 Chryseobacterium limigenitum SUR2 79.91 Chryseobacterium arthrosphaerae CC-VM-7 79.68 Chryseobacterium ginsenosidimutans THG 15(T) 79.63 Chryseobacterium oncorhynchi 701B-08(T) 79.52 Chryseobacterium balustinum DSM 16775 78.96

[0044] Therefore, by combining 16S rDNA sequence alignment and MAGA tree construction results, it can be determined that Chry.R1 is a new strain of the genus Chryseobacterium. We named it Chryseobacterium sp. Chry.R1 and classified it as Chryseobacterium sp. Chry.R1 was deposited in the Guangdong Provincial Culture Collection of Microorganisms (abbreviated as GDMCC), located on the 5th floor of Building 59, No. 100 Xianlie Middle Road, Guangzhou, Institute of Microbiology, Guangdong Academy of Sciences. The deposit number is GDMCC No. 63568, and the deposit date is June 16, 2023.

[0045] Example 3: Colony characteristics of Chry.R1

[0046] The strain Chry.R1 isolated in Example 1 was brownish-yellow and opaque on the beef extract peptone solid medium plate. The colonies were round and smooth, and the cells were viscous ( Figure 2 ).

[0047] The strain Chry.R1 was observed under a microscope, and the cells were spherical ( Figure 3 ). After detection, Chry.R1 of the present invention is a Gram-positive bacterium.

[0048] Example 4: Nitrogen fixation and antibacterial properties of Chry.R1

[0049] A loopful of the colonies of the strain Chry.R1 was streaked on the Ashby nitrogen-free medium and incubated in a constant temperature biochemical incubator at 30 °C for 48 hours. The growth situation is as Figure 4 shown. The results showed that Chry.R1 could grow well on the Ashby nitrogen-free medium, and it was preliminarily judged that the strain Chry.R1 had certain nitrogen fixation ability. Among them, the formula of the Ashby nitrogen-free medium is: 10 g / L mannitol, 0.2 g / L KH2PO4, 0.2 g / L MgSO4·7H2O, 0.2 g / L NaCl, 0.1 g / L CaSO4·2H2O, 5 g / L CaCO3.

[0050] The antibacterial ability of Chry.R1 was tested by the plate confrontation method. The pathogenic fungus Fusarium graminearum was activated from the slant to the center of the PDA plate and cultured at 25 °C for 5-7 days. When the colony grew to half of the diameter of the plate, it was identified as the target strain according to the colony characteristics and microscopic characteristics and then reserved. The Fusarium graminearum was made into a 5-mm diameter agar disc and placed in the center of the PDA plate. 5 μL of the Chry.R1 bacterial solution was pipetted and spotted at the edge of the plate. The photo when the pathogenic bacteria covered the plate is as Figure 5As shown, the two circular yellow areas and the edges of the plate are the Chry.R1 strain of the present invention, while the rest is the pathogenic fungus Fusarium graminearum, and there is no Fusarium graminearum around Chry.R1. The results show that Chry.R1 has a good inhibitory effect on Fusarium graminearum.

[0051] Example 5: Pot experiment on the growth promotion of Chry.R1

[0052] After activating the strain Chry.R1, it was inoculated into a beef extract peptone medium and fermented by shaking at 28 °C and 180 r / min for 5 days. Then, the OD600 of the fermented bacterial liquid was adjusted to 0.5, the bacterial liquid was taken, centrifuged at 5000 rpm for 10 min, the supernatant was removed, and the cells were resuspended with sterile water for use. The surface of soybean seeds (Zhonghuang 13) was disinfected with 1% sodium hypochlorite solution for 5 min and rinsed 5 times with sterile distilled water. The disinfected seeds were planted in sterile soil pots, and the sterile soil was obtained after being sterilized at 120 °C. 5 plants were planted in each pot. After the seeds germinated for 5 days, 5 mL of the bacterial liquid Chry.R1 was poured around the roots of the germinated plants in each pot, and the control group was watered with sterile water. 3 parallel groups were set for each treatment. The bacterial liquid Chry.R1 was watered once every 7 days for a total of 2 times. After 30 days, the plants in the pots were taken out and their growth indexes were measured. The specific measurement data are shown in Table 2, and the growth conditions of the treatment group (i.e., using the bacterial liquid Chry.R1) and the control group are as Figure 6 shown.

[0053] Table 2: Soybean growth indexes of the treatment group and the control group

[0054] Different treatments Plant height (mm) Root length (mm) Aboveground fresh weight (g) Underground fresh weight (g) Control group (mean ± standard deviation) 54.60±8.87 24.70±6.42 7.56±3.31 2.77±1.67 Treatment group (mean ± standard deviation) 91.80±12.53 27.80±5.23 9.58±1.86 2.82±2.00 Growth rate 68.13％ 12.55％ 26.63％ 1.95％ p-value 0.000733 0.483 0.351 0.975 p-value symbol *** ns ns ns

[0055] As can be seen from Table 2, applying the bacterial liquid Chry.R1 can increase the plant height, root length, above-ground fresh weight and underground fresh weight of soybeans, and the growth rates are 68.13%, 12.55%, 26.63% and 1.95% respectively. The significant difference analysis shows that applying the bacterial liquid Chry.R1 can extremely significantly increase the plant height of soybeans. From Figure 6 it can be seen that in the pot experiment, the plants after applying the strain Chry.R1 provided by the present invention have a higher plant height and a more lush underground part than the control group. The above results prove that applying the Chry.R1 strain can significantly promote the growth of soybeans.

[0056] Example 6: Field experiment on the growth promotion of Chry.R1

[0057] After activating the strain Chry.R1, it was inoculated into the beef extract peptone medium and fermented with shaking at 28 °C and 180 r / min for 5 days to obtain the Chry.R1 fermentation broth. Foxtail millet (Huagu 12) was planted in the field plots to verify the growth-promoting effect of Chry.R1 in gramineous crops. The Chry.R1 fermentation broth was inoculated at the seedling stage and jointing stage of foxtail millet respectively. When in use, the fermented bacterial liquid was diluted with tap water at a ratio of 1:100, and an equal amount of the fermented diluted liquid was irrigated for each crop. After 90 days of growth, the crops were sampled and the biomass data were statistically analyzed. The specific measurement data are shown in Table 3, and the growth conditions of the treatment group and the control group are as Figure 7 shown.

[0058] Table 3: Growth indexes of foxtail millet in the treatment group and the control group

[0059]

[0060] As can be seen from Table 3, compared with the control group, the application of the strain Chry.R1 effectively increased the plant height, aboveground fresh weight, underground fresh weight and ear weight of foxtail millet, and the growth rates were 19.11%, 24.12%, 33.33% and 28.89% respectively. The significance difference analysis showed that the application of the strain Chry.R1 extremely significantly increased the plant height of foxtail millet. From Figure 7 it can be seen that compared with the control group, the growth trend of the plants after applying the strain Chry.R1 provided by the present invention is good, the plants are taller and the ear is larger, indicating that the application of the strain Chry.R1 can significantly promote the growth of gramineous plants such as foxtail millet and has the function of increasing production. In addition, although the root length of foxtail millet decreased after applying the strain Chry.R1 compared with the control group, the underground fresh weight increased (Table 3). From Figure 7 it can be seen that the roots of the treatment group are thicker, indicating that the application of the strain Chry.R1 can promote root development, and thus achieve the beneficial effect of promoting plant growth.

[0061] The above has introduced in detail the Chryseobacterium Chry.R1 provided by the present invention and its application. Specific examples are used in this article to elaborate on the principle and implementation manner of the present invention. The description of the above examples is only used to help understand the method and its core idea of the present invention; at the same time, for those of ordinary skill in the art, according to the idea of the present invention, there will be changes in the specific implementation manner and application scope. In summary, the content of this specification should not be construed as a limitation to the present invention.

Claims

1. A Chryseobacterium, characterized in that, The sequence of the 16S rDNA of the Chryseobacterium is shown in SEQ ID NO:

1.

2. The Chryseobacterium according to claim 1, characterized in that, The preservation number of the Chryseobacterium is GDMCC No. 63568.

3. A bacterial agent comprising the Chryseobacterium according to claim 1 or 2.

4. The bacterial agent according to claim 3, characterized in that, The microbial agent is in liquid, powder or granular form.

5. Use of the Chryseobacterium according to claim 1 or 2 or the bacterial agent according to claim 3 or 4 for nitrogen fixation and / or inhibiting Fusarium graminearum during plant growth; preferably the plant is soybean or millet.

6. The use according to claim 5, characterized in that, The said use is achieved through the following steps: (1) Ferment the Chryseobacterium described in claim 1 or 2 or the microbial agent described in claim 3 or 4; (2) Use the fermented Chryseobacterium or microbial agent obtained in step (1) to perform root irrigation treatment during the sowing period and / or seedling stage, or emergence stage and / or jointing stage of the said plant.

7. Use of the Chryseobacterium according to claim 1 or 2 or the bacterial agent according to claim 3 or 4 for promoting plant growth; preferably the plant is soybean or millet.

8. The use according to claim 7, characterized in that, The said use is achieved through the following steps: (1) Ferment the Chryseobacterium described in claim 1 or 2 or the microbial agent described in claim 3 or 4; (2) Use the fermented Chryseobacterium or microbial agent obtained in step (1) to perform root irrigation treatment during the sowing period and / or seedling stage, or emergence stage and / or jointing stage of the said plant.

9. A method for culturing the Chryseobacterium according to claim 1 or 2, characterized in that, Inoculate the Chryseobacterium into the peptone beef extract medium with a pH of 7.4 - 7.6 and a culture temperature of 28°C.

10. The method according to claim 9, characterized in that, The components of the peptone beef extract medium include 10 g / L peptone, 3 g / L beef extract, and 5 g / L sodium chloride.

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