Bacillus amyloliquefaciens NTNK-3 and its application

Abstract

The present invention discloses a Bacillus amyloliquefaciens NTNK‑3 and its application. Bacillus amyloliquefaciens NTNK‑3 has been deposited in the Guangdong Provincial Microbial Culture Collection Center on July 6, 2022, and its deposit number is GDMCC No: 62606. The bacterium has the effect of inhibiting plant pathogenic fungi and weeds, and has an inhibitory effect on Colletotrichum gloeosporioides that causes anthracnose of pitaya and Penicillium digitatum that causes green mold disease of citrus; the germination inhibition rates of three weeds, barnyard grass, crabgrass and Amaranthus retroflexus, are 82.93%, 94.44% and 94.87% respectively, the root length inhibition rates of Setaria viridis and Amaranthus retroflexus are 96.2% and 91.84% respectively, and the stem length inhibition rates of Setaria viridis and Amaranthus retroflexus are 92.19% and 67.05% respectively.

Description

Technical Field

[0001] The invention relates to the technical field of biological control, and in particular to Bacillus amyloliquefaciens NTNK-3 and applications thereof. Background Art

[0002] Insect symbiotic bacteria are extremely abundant. Many insects have microorganisms in their bodies that form a symbiotic relationship with insects. Insects provide nutrients for symbiotic bacteria in their bodies, while symbiotic bacteria in insects can provide nutrients, vitamins and many other nutrients to the host. They can also assist the host insects in digesting food, regulating the host's nutritional metabolism, affecting the formation of the host's intestines, and helping the host resist infection by pathogens. Symbiotic bacteria extracted from insects can provide valuable uses in many aspects of life. In agriculture, insect symbiotic bacteria can be used to prevent and control diseases, insects, and weeds. In addition, they have many other functions such as decomposing garbage, antibacterial, anti-tumor, and anti-malarial.

[0003] Plant diseases caused by plant pathogenic fungi significantly reduce crop yield and quality, have a serious impact on crop safety production, and are one of the difficult problems that need to be solved in agricultural production. Farmland weeds are vigorous and compete with crops for nutrients and space, seriously affecting the growth of crops. For example, barnyard grass Echinochloa crusgal li (L.) Beauv., horsetail Digitaria sanguinalis (L.) Scop., foxtail grass Setaria viridis (L.) Be auv. and Amaranthus retroflexus L. are common malignant weeds in rice fields, wheat fields, corn fields and orchards. Some weeds even contain toxins in their bodies, which can cause poisoning to livestock after being eaten, such as Amaranthus retroflexus L., which is common in vegetable gardens and orchards. Therefore, weeds are another serious problem in agricultural safety production. In actual production, chemical fungicides and herbicides are often used to control plant diseases and weeds. Compared with natural fungicides and herbicides, natural fungicides and herbicides have the advantages of less environmental pollution, biodegradability, and less resistance. The secondary metabolites of microorganisms are one of the important sources for research and development of new fungicides and herbicides, and are safe, effective, non-toxic and pollution-free. Summary of the invention

[0004] The purpose of the present invention is to overcome the above-mentioned deficiencies in the prior art and provide a Bacillus amyloliquefaciens NTNK-3 and an application thereof.

[0005] The first object of the present invention is to provide Bacillus amyloliquefaciens NTNK-3.

[0006] The second object of the present invention is to provide the application of the Bacillus amyloliquefaciens NTNK-3 and / or its fermentation broth.

[0007] The third object of the present invention is to provide a biocontrol agent.

[0008] The fourth object of the present invention is to provide the use of the biocontrol agent.

[0009] A fifth object of the present invention is to provide a method for preventing and controlling plant diseases caused by Colletotrichum gloeosporioides and / or plant diseases caused by Penicillium digitatum.

[0010] A sixth object of the present invention is to provide a method for inhibiting Colletotrichum gloeosporioides and / or Penicillium digitatum.

[0011] A seventh object of the present invention is to provide a method for inhibiting the growth of plants in the Gramineae and / or Amaranthaceae family.

[0012] In order to achieve the above object, the present invention is implemented by the following scheme:

[0013] A Bacillus amyloliquefaciens NTNK-3, wherein the Bacillus amyloliquefaciens NTNK-3 has been deposited in the Guangdong Provincial Microbiological Culture Collection Center on July 6, 2022, and its preservation number is GDMCC No: 62606.

[0014] Application of the Bacillus amyloliquefaciens NTNK-3 and / or its fermentation broth in any one or more of the following:

[0015] Control of plant diseases caused by Colletotrichum gloeosporioides and / or Penicillium digitatum;

[0016] Preparation of preparations for preventing and controlling plant diseases caused by Colletotrichum gloeosporioides and / or plant diseases caused by Penicillium digitatum;

[0017] Inhibits Colletotrichum gloeosporioides and / or Penicillium digitatum;

[0018] Preparation of preparations for inhibiting Colletotrichum gloeosporioides and / or Penicillium digitatum;

[0019] Inhibit the growth of grass and / or amaranthaceae plants;

[0020] Preparation of a formulation for inhibiting the growth of grass and / or amaranthaceae plants.

[0021] Preferably, the plant disease caused by Colletotrichum gloeosporioides is pitaya anthracnose; and the plant disease caused by Penicillium digitatum is citrus green mold disease.

[0022] Preferably, the grass plant is barnyard grass, crabgrass and / or foxtail grass, and the Amaranthaceae plant is Amaranthus retroflexus.

[0023] Preferably, the inhibiting the growth of Gramineae and / or Amaranthaceae plants is inhibiting the germination, root and / or stem growth of Echinochloa crusgalli, Digitaria sanguinalis, Setaria viridis and / or Amaranthus retroflexus.

[0024] More preferably, the inhibiting the growth of Gramineae and / or Amaranthaceae plants is inhibiting the germination of Echinochloa crusgalli, Crabgrass and / or Amaranthus retroflexus, and inhibiting the root and / or stem growth of Setaria viridis and / or Amaranthus retroflexus.

[0025] A biocontrol preparation comprising Bacillus amyloliquefaciens NTNK-3 and / or its fermentation product.

[0026] The use of the biocontrol agent in any one or more of the following:

[0027] Control of plant diseases caused by Colletotrichum gloeosporioides and / or Penicillium digitatum;

[0028] Inhibits Colletotrichum gloeosporioides and / or Penicillium digitatum;

[0029] Inhibits the growth of grass and / or amaranth plants.

[0030] Preferably, the plant disease caused by Colletotrichum gloeosporioides is pitaya anthracnose; and the plant disease caused by Penicillium digitatum is citrus green mold disease.

[0031] Preferably, the grass plant is barnyard grass, crabgrass and / or foxtail grass, and the Amaranthaceae plant is Amaranthus retroflexus.

[0032] Preferably, the inhibiting the growth of Gramineae and / or Amaranthaceae plants is inhibiting the germination, root and / or stem growth of Echinochloa crusgalli, Digitaria sanguinalis, Setaria viridis and / or Amaranthus retroflexus.

[0033] More preferably, the inhibiting the growth of Gramineae and / or Amaranthaceae plants is inhibiting the germination of Echinochloa crusgalli, Crabgrass and / or Amaranthus retroflexus, and inhibiting the root and / or stem growth of Setaria viridis and / or Amaranthus retroflexus.

[0034] A method for preventing and controlling plant diseases caused by Colletotrichum gloeosporioides and / or Penicillium digitatum, wherein the Bacillus amyloliquefaciens NTNK-3 and / or its fermentation product are used for prevention and control.

[0035] Preferably, the plant disease caused by Colletotrichum gloeosporioides is pitaya anthracnose; and the plant disease caused by Penicillium digitatum is citrus green mold disease.

[0036] A method for inhibiting Colletotrichum gloeosporioides and / or Penicillium digitatum, which uses the Bacillus amyloliquefaciens NTNK-3 and / or its fermentation product for inhibition.

[0037] A method for inhibiting the growth of Gramineae and / or Amaranthaceae plants, using the Bacillus amyloliquefaciens NTNK-3 and / or its fermentation product for inhibition.

[0038] Preferably, the grass plant is barnyard grass, crabgrass and / or foxtail grass, and the Amaranthaceae plant is Amaranthus retroflexus.

[0039] Preferably, the inhibiting the growth of Gramineae and / or Amaranthaceae plants is inhibiting the germination, root and / or stem growth of barnyard grass, crabgrass, foxtail grass and / or Amaranthus retroflexus.

[0040] More preferably, the inhibiting the growth of Gramineae and / or Amaranthaceae plants is inhibiting the germination of Echinochloa crusgalli, Crabgrass and / or Amaranthus retroflexus, and inhibiting the root and / or stem growth of Setaria viridis and / or Amaranthus retroflexus.

[0041] Compared with the prior art, the present invention has the following beneficial effects:

[0042] The present invention discloses a Bacillus amyloliquefaciens NTNK-3 and its application. Bacillus amyloliquefaciens NTNK-3 and its application have been deposited in the Guangdong Provincial Microbial Culture Collection Center on July 6, 2022, and its deposit number is GDMCC No: 62606. The bacterium has the effect of inhibiting the growth of plant pathogenic fungi and weeds, and has an inhibitory effect on Colletotrichum gloeosporioides that causes pitaya anthracnose and Penicillium digitatum that causes citrus green mold disease; the germination inhibition rates of three weeds, barnyard grass, crabgrass and Amaranthus retroflexus, are as high as 82.93%, 94.44% and 94.87% respectively, the root length inhibition rates of Setaria viridis and Amaranthus retroflexus are 96.2% and 91.84% respectively, and the stem length inhibition rates of Setaria viridis and Amaranthus retroflexus are 92.19% and 67.05% respectively. The Bacillus amyloliquefaciens NTNK-3 of the present invention is derived from insects of the family Cerambycidae, has no adverse effects on the environment, has low production cost, a simple production process, does not pollute the environment, and is suitable for popularization and application. The bacteria are simple to culture, easy to store and produce, and the fermentation liquid can be used as a fungicide or a herbicide, which can play a very important role in the biological control of farmland plant diseases and weeds, and is an effective fungicide and herbicide with good development prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Figure 1 The colony morphology of Bacillus amyloliquefaciens NTNK-3 from the insect Pseudo-longhorn beetle on LB solid culture medium.

[0044] Figure 2 This is a phylogenetic tree constructed based on the 16S rDNA fragment sequence of Bacillus amyloliquefaciens NTNK-3.

[0045] Figure 3 The figure shows the inhibitory effect of the fermentation liquid of Bacillus amyloliquefaciens NTNK-3 on plant pathogens. A shows the growth of pitaya anthracnose in the CK group, B shows the confrontation between pitaya anthracnose and NTNK-3, C shows the growth of citrus green mold in the CK group, and D shows the confrontation between citrus green mold and NTNK-3.

[0046] Figure 4 This is a statistical chart showing the effect of Bacillus amyloliquefaciens NTNK-3 fermentation liquid on the germination rate of weeds.

[0047] Figure 5 This is a statistical chart showing the effect of Bacillus amyloliquefaciens NTNK-3 fermentation liquid on weed root growth.

[0048] Figure 6 This is a statistical graph showing the effect of Bacillus amyloliquefaciens NTNK-3 fermentation broth on the stem length of weeds. DETAILED DESCRIPTION

[0049] The present invention is further described in detail below in conjunction with the accompanying drawings and specific examples of the specification. The examples are only used to explain the present invention and are not used to limit the scope of the present invention. The test methods used in the following examples are conventional methods unless otherwise specified; the materials and reagents used are reagents and materials that can be obtained from commercial channels unless otherwise specified.

[0050] Example 1 Isolation, identification and preservation of strains

[0051] 1. Experimental Methods

[0052] 1. Isolation of strains

[0053] The test strain was isolated and cultured from the insect bodies of the Pseudoceramidae insects collected from the Mangrove Nature Reserve in Zhanjiang City, Guangdong Province (109°40′~110°35′E, 20°14′~21°35′N) in May 2021. The specific method is: starve the collected Pseudoceramidae insects for 3 days, wash the insects and place them on a plate, disinfect the insect surface with disinfectant alcohol for 3 minutes on a sterile clean bench, then disinfect with hydrogen peroxide for 5 minutes, then wash with sterile water 3 times, and grind with a sterile mortar. After thorough grinding, draw 150μL of grinding liquid onto the LB solid culture medium for coating, seal the coated culture medium with glue, and place it in a 28℃ incubator for light-proof culture. After culturing for about 3 days, pick a single colony to a new culture medium for further separation and purification after a single colony grows out. When the colony on the new culture medium is single and there is no pollution around the colony, pick a single colony into an LB slant test tube, and store it in a 4℃ refrigerator for standby use after culturing for 3 days. A pure culture of bacteria was obtained and the strain was named NTNK-3.

[0054] 2. Identification of strains

[0055] The NTNK-3 strain was inoculated on LB solid medium and cultured at a constant temperature of 28°C for 3 to 5 days. The colony diameter can reach 15 to 20 mm. The colony is milky white, the surface is relatively dry, and the edge of the colony is petal-like wrinkled ( Figure 1 NTNK-3 strain was inoculated into NA liquid culture medium and cultured at 28°C and 150 r / min for 3-5 days. The formula of the NA liquid culture medium was as follows: 3.0 g beef extract, 5.0 g peptone and 2.5 g glucose were added to 950 mL ionized water, and the volume was adjusted to 1000 mL after stirring and dissolving, and the pH was 7.0 and sterilized at 121°C for 15 min.

[0056] The genomic DNA of strain NTNK-3 was extracted according to the method of SteadyPure bacterial genomic DNA extraction kit, and the 16S rDNA fragment of the NTNK-3 strain was amplified with bacterial universal primers 27F / 1492R (27F: 5'-AGAGTTTGATCCTGGCTCAG-3'; 1492R: 5'-GGTTACCTTGTTACGACTT-3'). After electrophoresis test showed a single target band, sequencing was performed.

[0057] The sequencing results were spliced ​​with DNA sequences of bidirectional sequencing using SeqMan in Lasergene7. After splicing, they were searched and compared with other known sequences using BLAST in NCBI. After sequence comparison, gene sequences with homology above 98% were selected to download fasta format files of other sequences, and phylogenetic trees were constructed using MEGA 11 software.

[0058] 2. Experimental Results

[0059] The obtained sequence was compared with the database sequence in NCBI by BLAST homology, and the sequence similarity with the closely related Bacillus amyloliquefaciens strain Lac19F (MH210892) reached 100%, and the sequence comparison coverage rate reached 100%. The NTNK-3 strain was determined to be Bacillus amyloliquefaciens. The 16S rDNA nucleotide sequence of the NTNK-3 strain is shown in SEQ ID NO: 1. The phylogenetic tree of the NTNK-3 strain is shown in Figure 2 shown.

[0060] The NTNK-3 strain was named: Bacillus amyloliquefaciens NTNK-3, and was deposited in the Guangdong Provincial Microbial Culture Collection Center on July 7, 2022. Its deposit number is: GDMCC No: 62606, and the deposit address is 5th Floor, Building 59, No. 100, Xianlie Middle Road, Guangzhou. Example 2 Inhibitory Effect of Bacillus amyloliquefaciens NTNK-3 Fermentation Broth on Plant Pathogens

[0061] 1. Experimental Methods

[0062] 1. Experimental Materials

[0063] The pathogenic fungi tested were pitaya anthracnose (Colletotrichum gloeosporioides) and citrus green mold (Penicillium digitatum).

[0064] 2. Experimental methods

[0065] The Bacillus amyloliquefaciens NTNK-3 of Example 1 and the tested plant pathogenic fungi were inoculated on PDA solid culture medium, respectively, and placed in a 28°C incubator for 3-4 days. After culturing, a hole was punched on the culture medium under a sterile environment with a 5 mm diameter puncher, and the bacterial cakes of Bacillus amyloliquefaciens, pitaya anthracnose, and citrus green mold were taken out respectively, and Bacillus amyloliquefaciens NTNK-3 was cultured against pitaya anthracnose and citrus green mold, specifically:

[0066] The cakes of Bacillus amyloliquefaciens NTNK-3 and Colletotrichum spp. were placed upside down on both sides of a PDA solid culture medium, with a distance of 4 cm between the two cakes; the cakes of Bacillus amyloliquefaciens NTNK-3 and Citrus green mold were placed upside down on both sides of a PDA solid culture medium, with a distance of 4 cm between the two cakes; the two CK groups were inoculated with Colletotrichum spp. cakes but not with NTNK-3 cakes, and inoculated with Citrus green mold cakes but not with NTNK-3 cakes, respectively.

[0067] The samples were placed in a 28°C incubator for 5 days, and the diameters of pitaya anthracnose and citrus green mold were recorded and the inhibition rates were calculated. Each group of experiments was repeated three times.

[0068] The antibacterial rate calculation formula is:

[0069]

[0070] 2. Experimental Results

[0071] The experimental results are as follows Figure 3 As shown, the colony growth diameters of pitaya anthracnose (B) and citrus green mold (D) were significantly smaller than those of pitaya anthracnose (A) and citrus green mold (C) in the CK group (P<0.05), indicating that Bacillus amyloliquefaciens NTNK-3 has a great inhibitory effect on pitaya anthracnose pathogen (Colletotrichum gloeosporioides) and citrus green mold pathogen (Penicillium digitatum), with inhibition rates reaching 87.5% and 80.49% respectively (Table 1). This indicates that Bacillus amyloliquefaciens NTNK-3 is useful for inhibiting plant diseases caused by Colletotrichum gloeosporioides and Penicillium digitatum.

[0072] Table 1 Inhibition rate of Bacillus NTNK-3 on plant pathogenic fungi

[0073]

[0074] Note: Different lowercase letters in the same column of data represent significant differences at the P=0.05 level.

[0075] Example 3 Preparation of Bacillus amyloliquefaciens NTNK-3 fermentation broth

[0076] The Bacillus amyloliquefaciens NTNK-3 of Example 1 was inoculated into a conical flask containing 250 mL of NA liquid culture medium, and cultured under shaking conditions of 28° C. and 150 r / min for 3 to 5 days. The fermentation liquid obtained by culture is the fermentation liquid of Bacillus amyloliquefaciens NTNK-3, and the fermentation liquid contains Bacillus amyloliquefaciens NTNK-3. The formula of the NA liquid culture medium is the same as that of Example 1.

[0077] Example 4 Inhibitory effect of Bacillus amyloliquefaciens NTNK-3 fermentation broth on weed germination rate

[0078] 1. Experimental Methods

[0079] 1. Experimental Materials

[0080] The weed seeds tested were Echinochloa crusgalli (L.) Beauv., Digitariasanguinalis (L.) Scop., Amaranthus retroflexus L. and Setaria viridis (L.) Beauv.

[0081] 2. Experimental methods

[0082] The Bacillus amyloliquefaciens NTNK-3 of Example 1 was cultured in NA liquid medium for 3 days.

[0083] The experimental group took 20 seeds of barnyard grass, crabgrass, Amaranthus retroflexus and Setaria officinalis, and soaked them in 50°C warm water for 30 minutes. Put them on a culture medium with filter paper, add 2mL of Bacillus amyloliquefaciens NTNK-3 fermentation liquid of Example 3 to each culture medium to maintain humidity, put them in a 27°C incubator for dark culture for 3 days, and measure the seed germination rate of barnyard grass, crabgrass and Amaranthus retroflexus. The control group soaked the above 4 seeds in sterile water for 30 minutes, replaced the Bacillus amyloliquefaciens NTNK-3 fermentation liquid of Example 3 with sterile water, and the other parameters were the same as the experimental group. Each group was repeated 3 times. The germination rate and inhibition rate calculation formula are as follows:

[0084]

[0085] 2. Experimental Results

[0086] The experimental results showed that after treatment with the fermentation liquid of Bacillus amyloliquefaciens NTNK-3 of Example 3, the germination rates of barnyard grass, Amaranthus retroflexus and Digitaria were significantly lower than those of the CK group (P<0.05), and the inhibition rates were 82.93%, 94.87% and 94.44%, respectively (Table 2, Figure 4 The fermentation liquid of Bacillus amyloliquefaciens NTNK-3 in Example 3 had no significant inhibitory effect on the germination rate of Setaria viridis.

[0087] Table 2 Inhibitory effect of Bacillus amyloliquefaciens NTNK-3 on weed germination rate

[0088]

[0089] Note: Different letters after the same row of data in the table indicate significant differences at the P=0.05 level.

[0090] Example 5 Inhibitory Effect of Bacillus amyloliquefaciens NTNK-3 Fermentation Broth on Weed Roots and Stems

[0091] 1. Experimental Methods

[0092] 1. Experimental Materials

[0093] The weed seeds tested were Echinochloa crusgalli (L.) Beauv., Digitariasanguinalis (L.) Scop., Amaranthus retroflexus L. and Setaria viridis (L.) Beauv.

[0094] 2. Experimental methods

[0095] The experimental group placed filter paper in a culture dish, and then selected 24 seeds of barnyard grass, crabgrass, foxtail grass and Amaranthus retroflexus (the germination of the 24 weeds was required to be consistent), and the selected barnyard grass, crabgrass, foxtail grass and Amaranthus retroflexus seeds were placed on the culture dishes with filter paper. Use a pipette to add 2mL of Bacillus amyloliquefaciens NTNK-3 fermentation liquid of Example 3, cover the dish with a lid and culture it in a warm state. The control group replaced the fermentation liquid with clean water, and the other parameters were the same as the experimental group. Each treatment was repeated 3 times, and the treated culture base of each group was cultured in a 28℃ incubator with a light ratio of 14L:10D and a relative humidity of 80%. After 5 days of culture, the root and stem lengths of barnyard grass, crabgrass, foxtail grass and Amaranthus retroflexus were measured, and the statistical data were used to calculate the root length inhibition rate and stem length inhibition rate. The calculation formula for the root length and stem length inhibition rate is as follows:

[0096]

[0097] 2. Experimental Results

[0098] The experimental results show that the fermentation liquid of Bacillus amyloliquefaciens NTNK-3 in Example 3 has an inhibitory effect on the root and stem growth of Setaria and Amaranthus retroflexus. Compared with the root and stem growth length of the control group, the root length and stem length of the blank control group and the experimental group have significant differences (P<0.05). The inhibition rates of the fermentation liquid of Bacillus amyloliquefaciens NTNK-3 in Example 3 on the roots and stems of Setaria were 96.2% and 92.19, respectively, and the inhibition rates on the roots and stems of Amaranthus retroflexus were 91.84% and 67.05, respectively (Table 3, Figure 5 , Figure 6 The fermentation liquid of Bacillus amyloliquefaciens NTNK-3 in Example 3 had no significant inhibitory effect on the root and stem growth of barnyard grass and crabgrass.

[0099] Table 3 Inhibitory effect of Bacillus amyloliquefaciens NTNK-3 on root and stem length of weeds

[0100]

[0101] Note: CK means blank control; Different letters after the same row of data in the table indicate significant differences at P=0.05 level.

[0102] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit the protection scope of the present invention. For ordinary technicians in this field, other different forms of changes or modifications can be made based on the above descriptions and ideas. It is not necessary and impossible to list all the implementation methods here. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the claims of the present invention.

Claims

1. A Bacillus amyloliquefaciens NTNK-3, characterized in that: The Bacillus amyloliquefaciens NTNK-3 was deposited in the Guangdong Provincial Microbiological Culture Collection Center on July 6, 2022, and its preservation number is GDMCC No: 62606.

2. Use of the Bacillus amyloliquefaciens NTNK-3 and / or its fermentation broth as claimed in claim 1 in any one or more of the following: Control of plant diseases caused by Colletotrichum gloeosporioides and / or Penicillium digitatum; Preparation of preparations for preventing and controlling plant diseases caused by Colletotrichum gloeosporioides and / or plant diseases caused by Penicillium digitatum; Inhibits Colletotrichum gloeosporioides and / or Penicillium digitatum; Preparation of preparations for inhibiting Colletotrichum gloeosporioides and / or Penicillium digitatum; Inhibit the germination of barnyard grass, crabgrass or Amaranthus retroflexus; Inhibit root and / or stem growth of Setaria or Amaranthus retroflexus; Preparations for inhibiting the germination of barnyard grass, crabgrass or Amaranthus retroflexus; Preparations for inhibiting the root and / or stem growth of Setaria viridis or Amaranthus retroflexus; The fermentation liquid contains Bacillus amyloliquefaciens NTNK-3.

3. The use according to claim 2, characterized in that: The plant disease caused by Colletotrichum gloeosporioides is pitaya anthracnose; the plant disease caused by Penicillium digitatum is citrus green mold disease.

4. A biocontrol agent, characterized in that: The biocontrol agent comprises the Bacillus amyloliquefaciens NTNK-3 and / or its fermentation product according to claim 1; the fermentation product contains Bacillus amyloliquefaciens NTNK-3.

5. Use of the biocontrol agent according to claim 4 in any one or more of the following: Control of plant diseases caused by Colletotrichum gloeosporioides and / or Penicillium digitatum; Inhibits Colletotrichum gloeosporioides and / or Penicillium digitatum; Inhibit the germination of barnyard grass, crabgrass or Amaranthus retroflexus; Inhibits root and / or stem growth of Setaria or Amaranthus retroflexus.

6. The use according to claim 5, characterized in that: The plant disease caused by Colletotrichum gloeosporioides is pitaya anthracnose; the plant disease caused by Penicillium digitatum is citrus green mold disease.

7. A method for preventing and controlling plant diseases caused by Colletotrichum gloeosporioides and / or Penicillium digitatum, characterized in that: The control is carried out using the Bacillus amyloliquefaciens NTNK-3 and / or its fermentation product according to claim 1, wherein the fermentation product contains Bacillus amyloliquefaciens NTNK-3.

8. A method for inhibiting Colletotrichum gloeosporioides and / or Penicillium digitatum, characterized in that: The inhibition is carried out using the Bacillus amyloliquefaciens NTNK-3 and / or a fermentation product thereof according to claim 1, wherein the fermentation product contains Bacillus amyloliquefaciens NTNK-3.

9. A method for inhibiting the germination of barnyard grass, crabgrass or Amaranthus retroflexus, characterized in that: The inhibition is carried out using the Bacillus amyloliquefaciens NTNK-3 and / or a fermentation product thereof according to claim 1, wherein the fermentation product contains Bacillus amyloliquefaciens NTNK-3.

10. A method for inhibiting the root and / or stem growth of Setaria viridis or Amaranthus retroflexus, characterized in that: The inhibition is carried out using the Bacillus amyloliquefaciens NTNK-3 and / or a fermentation product thereof according to claim 1, wherein the fermentation product contains Bacillus amyloliquefaciens NTNK-3.

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