CN113502236A

CN113502236A - Burkholderia cepacia BcNLG515 strain and application thereof

Info

Publication number: CN113502236A
Application number: CN202110397248.6A
Authority: CN
Inventors: 许小霞; 洪莹莹; 金丰良; 王雪梅; 黄玲
Original assignee: South China Agricultural University
Current assignee: South China Agricultural University
Priority date: 2021-04-13
Filing date: 2021-04-13
Publication date: 2021-10-15
Anticipated expiration: 2041-04-13
Also published as: CN113502236B

Abstract

The invention discloses a new burkholderia cepacia BcNLG515 and application thereof. The invention provides a new burkholderia cepacia strain BcNLG515, which is preserved in Guangdong province microbial culture collection center (GDMCC) at 9-18 months in 2020, wherein the strain has the strain preservation number of GDMCC No: 61200. the experimental result shows that the Burkholderia pacia strain BcNLG515 has bacteriostatic activity on rice blast germs, and the harm of the rice blast germs to rice can be reduced by spraying BcNLG515 biocontrol bacteria liquid. Meanwhile, the sensitivity of the brown planthopper to nicotine can be obviously improved by spraying BcNLG515, the effect of the nicotine pesticide on controlling the brown planthopper is improved, and the biological control potential and the application prospect are good.

Description

Burkholderia cepacia BcNLG515 strain and application thereof

Technical Field

The invention belongs to the technical field of agricultural microorganisms. More particularly, relates to a new burkholderia cepacia strain BcNLG515 and application thereof.

Background

Burkholderia (Burkholderia) contains more than 80 species, of which Burkholderia cepacia complex (Bcc for short) is the most complex of the genus. Bcc is ubiquitous in soil, fresh water and plant rhizosphere. The Bcc strain can produce various antagonistic metabolites, including antibiotics such as phenazine (phenazine), nitropyrrolidin (pyrrolcitrin), candida xylostella (cepacidins) and the like, and various compounds such as siderophores, antibacterial polypeptides and the like, and has great biocontrol potential.

The Bcc strain can play a role in preventing diseases through mechanisms such as antibiotic production, competition, plant disease resistance induction and the like. Bcc has good inhibition effect on various plant fungal diseases such as pythium, rhizoctonia solani, fusarium wilt and fusarium. The Bcc has outstanding performances in the aspects of bioremediation, nitrogen fixation, plant growth promotion, biological control of plant diseases and the like, is a common plant-root promoting bacterium (PGPB), and has important economic and ecological values.

Soil-borne diseases caused by plant pathogenic fungi seriously affect the quality and quantity of agricultural products, and cause great economic loss if the agricultural products are not properly controlled. At present, chemical pesticides are still the mainstay of crop disease management. However, long-term use of chemical fungicides can pollute the environment, cause pathogenic bacteria to resist the drugs, and even cause the loss of beneficial flora in the rhizosphere of crops. Moreover, pathogenic fungi can exist in soil in the form of spores for a long time, and one-time spraying is difficult to completely remove. The biocontrol bacteria can survive in soil for a long time, can inhibit the growth of pathogenic bacteria through mechanisms such as secretion of antibacterial substances and the like, improve the disease resistance of crops, are green and environment-friendly disease control methods, and can promote the sustainable development of agriculture and improve the quality of agricultural products.

Chinese patent CN 109234211a discloses burkholderia, which is deposited in the chinese typical culture collection with the collection number of CCTCC NO: m2018703, the strain has the functions of preventing and treating sheath blight, rice blast and bakanae disease of rice. Chinese patent CN 109452312A discloses a Burkholderia plantarii CGB10, which has broad-spectrum disease resistance and strong inhibition effect on filamentous fungus diseases such as colletotrichum hejinseyi (anthracnose of cabbage), fusarium oxysporum (fusarium wilt of banana), rice blast (rice blast), litchi anthracnose (litchi anthracnose), peronophythora litchii (litchi peronophythora litchii), sugarcane smut (sugarcane smut) and the like. However, domestic Bcc different genotype strains do not screen main plant pathogens much at present, and screening of new Burkholderia with biocontrol effect still has important scientific value and practical value.

Disclosure of Invention

The invention aims to solve the technical problem of providing a new burkholderia cepacia BcNLG515 strain and application thereof to overcome the defects and shortcomings.

The first purpose of the invention is to provide a new burkholderia cepacia BcNLG515 strain.

The second purpose of the invention is to provide the application of the BcNLG515 strain in preventing and controlling rice blast or in preparing a preparation for preventing and controlling rice blast.

The third purpose of the invention is to provide the application of the BcNLG515 strain in improving the sensitivity/insecticidal activity of the nicotine pesticide to insects.

The fourth purpose of the invention is to provide the application of the BcNLV 515 strain in controlling the brown planthopper or preparing a preparation for controlling the brown planthopper.

The fifth purpose of the invention is to provide the application of the zymocyte liquid of the BcNLG515 strain in improving the insecticidal activity of the nicotine pesticide on insects.

The sixth object of the present invention is to provide a biocontrol agent having an inhibitory effect on rice blast and capable of improving the sensitivity of brown planthopper to nicotine.

It is a seventh object of the present invention to provide a method for enhancing the insect control effect of nicotine.

The above purpose of the invention is realized by the following technical scheme:

the new Burkholderiacepacia cepacia strain BcNLG515 is preserved in Guangdong province microbial strain preservation center (GDMCC) at 9 and 18 days 2020, the preservation address is No. 59 building 5 of Michelia Torilensis No. 100 of Guangzhou city of Guangzhou province, and the strain preservation number is GDMCC No: 61200. the 16rDNA nucleotide sequence of the strain is shown in SEQ ID NO. 1.

The invention discloses a burkholderia cepacia strain BcNLG515 separated from the intestines of a brown planthopper female adult, and the PDA plate bacteriostasis experiment shows that the BcNLG515 has strong inhibition effect on the growth of rice blast germs. Through observing the experiments of spraying BcNLG515 fermentation liquor and rice blast germ suspension liquid to treat rice at different time points, the spraying of BcNLG515 biocontrol bacteria liquid can reduce the damage of rice blast germ to rice, and the spraying of BcNLG515 biocontrol bacteria liquid 24h before the spraying of the rice blast germ suspension liquid has the advantages of minimum scab number, best effect, obvious difference level and capability of preventing and treating rice blast, thereby showing that the BcNLG515 can be used for preventing and treating rice blast. The invention also discovers that the BcNLG515 biocontrol bacteria liquid can obviously improve the sensitivity of the brown planthopper to nicotine by observing a rice immersion method, improves the control effect of nicotine pesticide on the brown planthopper of rice, and has better synergistic effect.

Accordingly, the present invention provides the following applications with respect to Burkholderiacepacia strain BcNLG 515:

application of Burkholderia pacia strain BcNLG515 in preventing and treating rice blast or in preparing rice blast preventing and treating preparation.

The Burkholderiacepacia strain BcNLG515 is used in raising the sensitivity and pesticidal activity of nicotine pesticide to insect.

Application of fermentation bacteria liquid of Burkholderia pacia strain BcNLG515 in preventing and treating brown planthopper or in preparing preparation for preventing and treating brown planthopper.

Application of fermentation bacteria liquid of Burkholderia pacia strain BcNLG515 in improving insecticidal activity of nicotine pesticide on insects.

Preferably, the Pyricularia oryzae is MoZC13 strain.

The invention also provides a biocontrol preparation which has an inhibiting effect on rice blast and can improve the nicotine sensitivity of brown planthopper, and the active ingredient of the biocontrol preparation is BcNLG515 strain thalli.

Preferably, the active ingredient of the biocontrol agent is BcNLG515 strain thallus fermentation liquor.

More preferably, the concentration of the bacterial fermentation broth is 1X 10⁷～1×10⁸/CFU。

The present invention also provides a method of enhancing the control of insects by nicotine by exposing the insects to the bacterium BcNLG515 for several days prior to nicotine treatment of the insects.

Preferably, the insect is brown planthopper.

The invention has the following beneficial effects:

Drawings

FIG. 1 is a photograph of a plate of isolate of strain BcNLG 515.

FIG. 2 is a 16rRNA phylogenetic analysis of Nilaparvata lugens adult intestinal isolate BcNLG 515.

FIG. 3 shows the antagonistic action of the strain BcNLG515 on rice blast.

FIG. 4 is an observation of the control effect of the strain BcNLG515 biocontrol bacterial liquid on Pyricularia oryzae, wherein A is the control effect of spraying BcNLG515 biocontrol bacterial liquid 24h before Pyricularia oryzae treatment; b, treating the rice blast germs and spraying a control group of a liquid LB culture medium at the same time; c is the prevention and control effect of spraying BcNLG515 biocontrol bacteria liquid after rice is treated for 24h by rice blast germs.

FIG. 5 shows that the biological control bacterium liquid BcNLG515 can increase the sensitivity of Nilaparvata lugens to nicotine.

Note: labeled on each branch in fig. 2 are: GenBank serial No. + strain name.

Detailed Description

The invention is further described with reference to the drawings and the following detailed description, which are not intended to limit the invention in any way. Reagents, methods and apparatus used in the present invention are conventional in the art unless otherwise indicated.

Unless otherwise indicated, reagents and materials used in the following examples are commercially available.

EXAMPLE 1 isolation culture of Strain BcNLG515

1. Preparation of Selective isolation Medium

LB culture medium: 10g of peptone, 5g of yeast extract, 10g of sodium chloride, 15g of agar, and 1L of sterile ddH₂Adjusting the pH value to 7.0 in O water;

isolation of the medium EB: 3g of beef extract powder, 10g of tryptone, 15g of yeast powder, 5g of sodium chloride, 10g of glucose and 15g of agar, dissolving the beef extract powder, the glucose and the agar in 1L of sterile water, and adjusting the pH value to 7.2 +/-0.2;

the NA culture medium comprises 10g of tryptone, 3g of beef extract powder, 5g of sodium chloride and 15g of agar, and is dissolved in 1L of sterile water, and the pH value is adjusted to 7.2 +/-0.2.

2. Dissecting and plating: dissecting intestinal tracts of the brown planthopper female adults in PBS (phosphate buffer solution), grinding the intestinal tracts into homogenate by using a handheld electric grinder, diluting the homogenate by 4 concentration gradients, coating the homogenate on three culture media, repeating the treatment for three times, culturing the homogenate in a constant-temperature incubator at 37 ℃, and observing the homogenate once every 24 hours.

3. Culture with continuous purification and photographing: after a single colony grows out in the selective culture medium, firstly, selecting the single colony according to the color, size and shape of the colony, continuously streaking and purifying the single colony on a corresponding culture medium for more than 5 times, then, photographing a streaking plate for separating a strain (shown in figure 1), transferring the streaking plate into an LB liquid culture medium, when the streaking plate is cultured to a bacterial exponential growth phase by shaking, storing the streaking plate in 25% glycerol aqueous solution, and freezing and storing the streaking plate in a refrigerator at minus 80 ℃ for later use. Example 2 identification of Strain BcNLG515 and phylogenetic analysis

1. Conventional biological assays

(1) Morphological characteristics of bacterial colony

From the morphology, colonies of the BcNLG515 strain on an LB culture medium are circular or oval, the colonies are milky white, the edges are complete, and the colonies are opaque. As shown in the attached figure 1, the BcNLG515 strain is a raised, wavy and wet colony on an LB solid culture medium, the colony after 24h culture is relatively small, and the diameter of the colony is 1-2 mm. The BcNLG515 strain is also raised, wavy and wet colony on EB solid culture medium, and the colony after 24 hr culture is 2-4 mm greater than that on LB culture and has diameter. The BcNLG515 strain can grow at room temperature and 37 deg.c, has no growth at 4 deg.c and 42 deg.c and grows well at pH7.2.

(2) Physiological and biochemical characteristic determination of intestinal isolation BcNLG515 strain

The BcNLG515 strain is antagonistic bacterium, and the bacterium is short rod-shaped gram-negative bacterium. Meanwhile, the physiological and biochemical characteristics of the antagonistic bacteria are as follows: can decompose sucrose, fructose, xylose, mannitol, glycerol, glucose, alanine, citric acid and inositol, but not lactose, ethanol and arginine. Can decompose ammonium chloride, ammonium sulfate, potassium nitrate, ammonium nitrate, glutamic acid and urea, but can not hydrolyze starch, and can liquefy gelatin. The pH range of normal growth is 5-8, and the cellulose degradation capacity and the phosphate solubilizing capacity are relatively strong (shown in table 1).

TABLE 1 Biochemical characteristics of BcNLG515

Gram reaction	-
		H₂O₂Enzyme reaction	+
Alanine	+
		Inositol	+
Mannitol	+
		Citric acid	+
Urea	+
		Xylose	+
Ammonium nitrate	+
		Starch	-
Glycerol	+
		Ammonium chloride	+
Lactose	-
		Ethanol	-
Sucrose	+
		Glucose	+
Arginine	-

2. Molecular biological identification

(1) The stored genomic DNA of the monoclonal strain was extracted using a bacterial genomic DNA extraction Kit (TIANAmp Bacteria DNA Kit) from Tiangen organisms, and 16rDNA of the Bacteria was amplified using the extracted DNA as a template and 16rDNA universal primers 27F (5 '-AGTTTGATCMTGGCTCAG-3') and 1492R (5'-GGTTACCTTGTTACGACTT-3') as upstream and downstream primers, and the PCR reaction system was as shown in Table 2.

TABLE 2 bacterial 16rDNA PCR amplification System (20. mu.L)

After the reaction system was gently mixed, the mixture was centrifuged briefly and placed on a PCR instrument to react according to the following procedure: pre-denaturation at 98 ℃ for 2 min; denaturation at 98 ℃ for 10s, annealing at 50 ℃ for 15s, and extension at 72 ℃ for 15s for 30 cycles; 72 ℃ for 5 min; and (3) performing programmed reaction at 10 ℃, detecting a PCR product by using 1% agarose gel, cutting the gel, recovering and purifying, and sending the PCR product to Guangzhou Pongke biotechnology Limited company for sequencing and identification.

(2) Phylogenetic analysis of intestinal isolate BcNLG515

The sequencing results of sequencing primers 27F and 1492R were analyzed and the sequence was spliced with seqman (dnastar), then blast-aligned with rRNA/ITS database in NCBI and uploaded to GenBank database with sequence number: MW 386480. Taking a downloaded and sorted near sequence similar to the intestinal isolate BcNLG515 strain, performing multi-sequence comparison analysis by using ClustalW software, then constructing a phylogenetic tree by using Mega7.0 software and adopting an adjacent method (Neighbor-Joining), adjusting a bootstrap value and checking the reliability of the phylogenetic tree. As shown in fig. 2, it can be seen from fig. 2 that BcNLG515 has the highest similarity to burkholderia straain camp 1040(NR 159299.1) and burkholderia pacia 717(NR 029209.1), and is named as burkholderia cepacia new brown planthopper burkholderia cepacia pacia BcNLG515 strain, which has been deposited at the Guangdong province collection of microorganisms (GDMCC) at 9 and 18 months 2020, with the strain number GDMCC No: 61200, classification name BcNLG515, preservation address of Guangdong province Guangzhou city, first furious Zhonglu 100 large yard, No. 59 building, No. 5 building.

Example 3BcNLG 515 bacteriostasis assay

A circle drawing method is adopted: placing a 5 mm-diameter rice blast germ MoZC13 bacterial sheet (stored in a laboratory) in the center of a PDA culture medium, dipping a small amount of BcNLG515 bacterial liquid in an exponential growth phase, drawing a circle with the diameter of about 5cm, drawing a circle with the dipped LB liquid culture medium as a control group, and repeating each treatment for three times, wherein the culture box conditions are as follows: the temperature is 25 ℃ and the humidity is 75 percent. The inhibitory effect of BcNLG515 was evaluated by measuring the diameter of rice blast germs after 7 days of co-culture, setting three replicates A, B and C, and the results are shown in FIG. 3 and Table 4.

FIG. 3A is a plate image of Pyricularia oryzae MoZC13 after culture for 7d, and FIG. 3B is a plate image of BcNLG515 strain co-cultured with Pyricularia oryzae MoZC13 after culture for 7 d. The result shows that the BcNLG515 strain can obviously inhibit the growth of rice blast germ. As is clear from Table 4, the diameter of 7d of the rice blast fungus MoZC13 cultured in the dish was 8.1cm, and the diameter of 7d of the rice blast fungus MoZC13 and BcNLG515 cultured in the dish after circling was 2.2cm, indicating that BcNLG515 had a strong inhibitory effect on the rice blast fungus MoZC 13.

TABLE 4 antagonistic action of BcNLG515 Strain on Magnaporthe grisea MoZC13

Three experiments	MoZC13 diameter (cm)	BcNLG515+ MoZC13 diameter (cm)
			A	8.1	2.2
B	8.2	2.2
			C	8.2	2.4

Example 4 inhibition of BcNLG515 biocontrol bacteria on Rice blast

1. Preparation of biocontrol bacteria liquid

Inoculating glycerol strain preserved at-80 deg.C and culture medium at volume ratio of 1: 100 into fresh LB liquid culture medium, activating at 37 deg.C for about 14 hr at 220rpm/min to obtain seed solution. Inoculating the seed bacteria and a fresh culture medium LB in a volume ratio of 1: 100 to a fresh LB liquid culture medium, and shaking at the temperature of 37 ℃ for about 6 hours at the rpm/min to obtain the bacterium BcNLG515 with stronger activity. Taking 1mLBcNLG 515 bacterial liquid to ferment for 7d in 100mL of fresh LB liquid culture medium at 130rpm/min and 27 ℃ to obtain biocontrol bacterial liquid which is prepared into 0.5-1 multiplied by 10⁸CFU/mL bacterial liquid.

2. Preparation of Magnaporthe grisea MoZC13 spores

Culturing Magnaporthe grisea MoZC13 at 25 deg.C under 75% humidity, carefully opening MoZC13 activated for 10 days in a super clean bench, scraping aerial hyphae, and illuminating under temperature: 25 ℃, humidity: 90%, photoperiod: spore is produced for 2 days in 12-12 h. The culture medium with the produced MoZC13 spores is taken out, the culture medium is downwards and reversely buckled in a culture dish containing 4mL of sterile water, a glass coating rod is used for lightly scratching the back surface of the culture medium, the spore suspension is sucked, the operation is repeated for three times, and the mixture is counted. Finally, the spore concentration is calculated by using a blood cell plate, and the spore concentration is adjusted to 5 x 10⁵CFU/mL。

3. Treating rice leaves

The rice in the jointing stage with uniform growth is selected and divided into 3 groups, which are respectively marked as B24, CK and A24, and each group has 3 repetitions. Wherein, B24 is spraying biological control bacterium liquid 24h before the suspension of Magnaporthe grisea is sprayed, A24 is spraying biological control bacterium liquid 24h after the suspension of Magnaporthe grisea is sprayed, CK is spraying LB culture medium at the same time of the suspension of Magnaporthe grisea. 5mL of biocontrol bacteria liquid/LB culture medium and 2mL of rice blast germ suspension. The disease condition is observed after the rice blast germ spore suspension is sprayed and cultured in the dark for 24h, and the heat preservation and moisture preservation culture is carried out for 7d, and the experimental result is shown in figure 4. Wherein, FIG. 4A shows the control effect of BcNLG515 biocontrol bacteria liquid sprayed 24h before the blast fungus treatment (B24); FIG. 4B Control (CK) of Magnaporthe grisea treatment with LB medium spray; FIG. 4C shows the control effect of BcNLG515 biocontrol bacterial liquid spray after rice blast germ treatment for 24h (A24). The result shows that the spraying of the biocontrol bacterium liquid BcNLG515 can obviously reduce the damage of rice blast germs to rice, and the best is to spray the biocontrol bacterium liquid BcNLG515 on the rice in advance, so the control effect is the best.

Example 5BcNLG515 synergistic Effect on Nicotine

1. Preparation of bacterial liquid

Inoculating glycerol strain stored at-80 deg.C and culture medium at volume ratio of 1: 100 into fresh LB liquid culture medium, activating at 37 deg.C for about 14 hr at 220rpm/min to obtain seed strain. Seed bacteria and fresh medium LB are mixed in a volume ratio of 1: 100, inoculating the seed bacteria to a fresh LB liquid culture medium, and shaking at 220rpm/min and 37 ℃ for about 6h to obtain the bacteria with stronger activity. Sucking activated bacteria liquid, centrifuging at 8000rpm for 3min, sucking supernatant, adding equal-volume sterile PBS for resuspension, and diluting to 1 × 10 with PBS⁸CFU/ml。

2. Preparation of nicotine

90% nicotine stored in the laboratory is absorbed by 18 mu L and added into 100mL of clear water to prepare a nicotine solution with the concentration of 180mg/L for later use.

3. Rice steeping process

Taking out the rice which grows for about 30 days and has consistent growth vigor from the roots, cleaning the rice, and cutting the rice into 10cm long. Placing in shade, air drying, soaking in nicotine solution for 1min, taking out, air drying in shade with clear water as control, wrapping root with absorbent cotton, placing in raw measuring cup, adding water into the cup with injector during experiment, and keeping absorbent cotton wet.

The method comprises the following specific operations:

selecting rice with uniform growth for about 30 days, dividing into 2 groups, repeating each group for 8 times, repeating each group for 4-5 times, placing into a raw measuring cup (disposable plastic cup, height: 17cm, volume: 700mL), and spraying 2mL of rice with concentration of 1 × 10⁸And (3) inoculating 15-20 brown planthoppers 1-2 d female adults into the CFU/ml BcNLG515 or equivalent clear water. Culturing in an artificial climate box for 3 days (temperature: 25-27 ℃, humidity: 75%, photoperiod: 14-10 h). Each group was divided into 2 groups, 4 replicates each, and surviving brown planthoppers were transferred separately to rice treated with clear water and nicotine (180mg/L) (rice maceration method). The cultivation is carried out in a climatic chamber, and the death rate of 3d, 5d and 7d brown planthopper is recorded. As shown in fig. 5, it is known that BcNLG515 can improve the sensitivity of brown planthopper to nicotine. Diluting BcNLG515 bacterial liquid 10 times, and using 1X 10⁷The same treatment was performed with CFU/ml BcNLG515 and the same experimental results were obtained. In addition, in the experiment, BcNLG515 biocontrol bacteria liquid (1X 10) alone was used⁸CFU/ml) and PBS, the mortality rate of brown planthopper in the two groups was found to be statistically different without significance three days after the brown planthopper was treated with PBS, indicating that BcNLG515 could not cause the death of brown planthopper. The results further indicate that BcNLG515 may have a synergistic effect, increasing Nicotine sensitivity of Nilaparvata lugens.

In conclusion, the screened burkholderia cepacia strain BcNLV 515 (the preservation number is GDMCCNO 61200) has strong antagonism on Pyricularia oryzae, can effectively prevent and control the damage of the Pyricularia oryzae on rice, enhances the sensitivity of Nilaparvata nilotica on nicotine, improves the effect of Nicotinamide pesticides on Nicotinamide planthopper, and has wide application prospect in the field.

The above embodiments are preferred embodiments of the present invention, but the present invention is not limited to the above embodiments, and any other changes, modifications, substitutions, combinations, and simplifications which do not depart from the spirit and principle of the present invention should be construed as equivalents thereof, and all such changes, modifications, substitutions, combinations, and simplifications are intended to be included in the scope of the present invention.

Sequence listing

<120> new burkholderia cepacia BcNLG515 strain and application thereof

<160> 1

<170> SIPOSequenceListing 1.0

<210> 1

<211> 1445

<212> DNA

<213> Burkholderia cepacia (Burkholderia cepacian)

<400> 1

cagcgaaggg gggcagcctt aacatgcaag tcgaacggca gcacgggtgc ttgcacctgg 60

tggcgagtgg cgaacgggtg agtaatacat cggaacatgt cctgtagtgg gggatagccc 120

ggcgaaagcc ggattaatac cgcatacgat ctacggatga aagcggggga ccttcgggcc 180

tcgcgctata gggttggccg atggctgatt agctagttgg tggggtaaag gcctaccaag 240

gcgacgatca gtagctggtc tgagaggacg accagccaca ctgggactga gacacggccc 300

agactcctac gggaggcagc agtggggaat tttggacaat gggcgaaagc ctgatccagc 360

aatgccgcgt gtgtgaagaa ggccttcggg ttgtaaagca cttttgtccg gaaagaaatc 420

cttggctcta atacagtcgg gggatgacgg taccggaaga ataagcaccg gctaactacg 480

tgccagcagc cgcggtaata cgtagggtgc gagcgttaat cggaattact gggcgtaaag 540

cgtgcgcagg cggtttgcta agaccgatgt gaaatccccg ggctcaacct gggaactgca 600

ttggtgactg gcaggctaga gtatggcaga ggggggtaga attccacgtg tagcagtgaa 660

atgcgtagag atgtggagga ataccgatgg cgaaggcagc cccctgggcc aatactgacg 720

ctcatgcacg aaagcgtggg gagcaaacag gattagatac cctggtagtc cacgccctaa 780

acgatgtcaa ctagttgttg gggattcatt tccttagtaa cgtagctaac gcgtgaagtt 840

gaccgcctgg ggagtacggt cgcaagatta aaactcaaag gaattgacgg ggacccgcac 900

aagcggtgga tgatgtggat taattcgatg caacgcgaaa aaccttacct acccttgaca 960

tggtcggaat cccgctgaga ggtgggagtg ctcgaaagag aaccggcgca caggtgctgc 1020

atggctgtcg tcagctcgtg tcgtgagatg ttgggttaag tcccgcaacg agcgcaaccc 1080

ttgtccttag ttgctacgca agagcactct aaggagactg ccggtgacaa accggaggaa 1140

ggtggggatg acgtcaagtc ctcatggccc ttatgggtag ggcttcacac gtcatacaat 1200

ggtcggaaca gagggttgcc aacccgcgag ggggagctaa tcccagaaaa ccgatcgtag 1260

tccggattgc actctgcaac tcgagtgcat gaagctggaa tcgctagtaa tcgcggatca 1320

gcatgccgcg gtgaatacgt tcccgggtct tgtacacacc gcccgtcaca ccatgggagt 1380

gggttttacc agaagtggct agtctaaccg caaggaggac ggtcaccacg gtaggattca 1440

gatgt 1445

Claims

1. The burkholderia cepacia strain BcNLG515 is characterized in that the strain is preserved in Guangdong province microbial culture collection (GDMCC) at 9-18 months in 2020, and the strain preservation number is GDMCC No: 61200.

2. the strain of claim 1, wherein the nucleotide sequence of 16rDNA of the strain is shown in SEQ ID NO. 1.

3. Use of the strain of claim 1 for controlling rice blast or for preparing a formulation for controlling rice blast.

4. Use of a strain according to claim 1 for increasing the insect sensitivity/insecticidal activity of a nicotinic pesticide.

5. Use of the strain according to claim 1 for controlling brown planthopper or for preparing a preparation for controlling brown planthopper.

6. A biocontrol agent having an inhibitory effect on rice blast and capable of improving nicotine sensitivity of Nilaparvata lugens, which comprises as an active ingredient the fungus bodies of the strain of claim 1.

7. The biocontrol agent according to claim 6, wherein a fermentation broth of the bacterial cells of the strain of claim 1 is used as an active ingredient.

8. The biocontrol bacterial liquid according to claim 7, wherein the concentration of the bacterial fermentation liquid is 1X 10⁷～1×10⁸/CFU。

9. A method of enhancing the control of insects by nicotine comprising exposing the insects to the bacterium BcNLG515 for a period of days prior to nicotine treatment of the insects.

10. The use according to claim 4 or the method according to claim 9, wherein the insect is brown planthopper.