CN111548976A

CN111548976A - Paenibacillus polymyxa strain and application thereof

Info

Publication number: CN111548976A
Application number: CN202010583952.6A
Authority: CN
Inventors: 杨利娟; 高苇; 张春祥; 王勇
Original assignee: TIANJIN INSTITUTE OF PLANT PROTECTION
Current assignee: Tianjin Academy of Agricultural Sciences
Priority date: 2020-06-24
Filing date: 2020-06-24
Publication date: 2020-08-18
Anticipated expiration: 2040-06-24
Also published as: CN111548976B

Abstract

The invention discloses a paenibacillus polymyxa strain and application thereof, wherein the strain is paenibacillus polymyxa LQ19 with the preservation number of CGMCC NO. 19097. The bacterial strain has a wide antibacterial spectrum, has an antibacterial effect on rot pathogens of roots and stems of horticultural crops and field crops of more than 73 percent, has an antibacterial effect on fungoid and bacterial pathogens of leaves of crops of more than 78 percent, and can be used for preventing and treating soil-borne diseases and air-borne diseases. Meanwhile, the strain is safe to crops, can promote seed germination and crop growth, has good drug effect persistence, is not easy to generate drug resistance, can effectively reduce the use amount of chemical pesticides, is beneficial to pollution-free production of crops, and has very wide application prospect in biological control of plant diseases.

Description

Paenibacillus polymyxa strain and application thereof

Technical Field

The invention belongs to the technical field of bactericides and relates to a paenibacillus polymyxa strain and application thereof.

Background

Guaranteeing national food safety and ecological safety is a global important strategic problem relating to national economic development and social stability. The scientific development of plant protection work is the key to the production and income increase of agriculture. The root rot of crops has the characteristic of difficult prevention and control, is mostly caused by fusarium, pythium and the like, and is characterized in that the root part is discolored and rotted, and when the root part is seriously rotted or withered and dead, the crops are threatened to grow healthily. At present, the rot of the root and the stem of crops is mainly controlled by a chemical seed treatment or root irrigation mode, the leaf diseases are mainly controlled by a chemical spraying mode, and although the chemical has outstanding advantages in disease control, the problems of drug resistance, ecological environment pollution, food safety and the like are increasingly prominent because the chemical is not scientifically used. With the enhancement of environmental awareness of people, the attention to food safety problems and the requirement of agricultural sustainable development, the implementation of a drug-reducing synergistic green prevention and control technology is the trend of the development of the plant protection industry, so that biological prevention and control become a hot spot of current research and development.

Paenibacillus polymyxa (B) ((B))Paenibacillus polymyxa) The bacterium has broad-spectrum antibacterial activity, can effectively prevent and treat bacterial and fungal diseases of plants, and has obvious effects of promoting growth and increasing yield of the plants. The microbial preparation exists in a spore form, has good temperature resistance, stable quality, lasting pesticide effect and no any phytotoxicity or residue, and is a preferred microbial preparation for producing pollution-free, green and organic vegetables. The united states Environmental Protection Agency (EPA) has listed it as one of the commercially available microbial species. The paenibacillus polymyxa has better application prospect in agricultural disease control.

Disclosure of Invention

The invention aims to provide a strain of paenibacillus polymyxa (B.) (Paenibacillus polymyxa) And applications thereof.

In a first aspect, the invention claims a strain of paenibacillus polymyxa:

the strain claimed by the invention is paenibacillus polymyxa LQ19, which is preserved in the China general microbiological culture Collection center (CGMCC) with the preservation number of CGMCC No.19097 and the preservation time of 2019, 12 and 05 days. The Paenibacillus polymyxa strain (A)Paenibacillus polymyxa) The nucleotide sequence of LQ19 is shown in SEQ ID NO. 1.

Deposit description

The strain name is as follows: paenibacillus polymyxa

Latin name:Paenibacillus polymyxa

the strain number is as follows: LQ19

The preservation organization: china general microbiological culture Collection center

The preservation organization is abbreviated as: CGMCC (China general microbiological culture Collection center)

Address: xilu No.1 Hospital No. 3 of Beijing market facing Yang district

The preservation date is as follows: year 2019, month 12 and day 05

Registration number of the preservation center: CGMCC No.19097

Bacterial colony characteristics of paenibacillus polymyxa:

the bacterial colony on the NA culture medium has smooth surface, is milk white and translucent, and has viscosity, the bacterial colony is rod-shaped, is distributed singly or in an arrangement mode, the size is (1.1-2.3) mu m × (0.4-0.7), the spore is oval, the cyst is expanded, the middle growth to the terminal growth, the gram staining is positive, the flagellum is peribiotic, and the paenibacillus polymyxa strain (the bacterial colony is a bacterial colony with a certain concentration, the bacterial colony is a bacterial colony with a certain concentrationPaenibacillus polymyxa) The nucleotide sequence of LQ19 is shown in SEQ ID NO. 1.

In a second aspect, the invention claims a microbial preparation or bacterial manure.

The microbial preparation or bacterial manure claimed by the invention contains the paenibacillus polymyxa (A)Paenibacillus polymyxa) LQ 19. Further, the microorganismThe preparation can be a biocontrol preparation or a bacterial manure. Still further, the biocontrol agent may be prepared from said Paenibacillus polymyxa (R) ((R))Paenibacillus polymyxa) LQ19 and auxiliary materials or auxiliary agents, wherein the auxiliary materials comprise grass carbon, crop straws, rice hulls, animal wastes and the like, and the auxiliary agents mainly comprise carriers, emulsifying agents, dispersing agents, wetting agents and the like. The strain can be processed into various formulations, such as liquid, emulsion, suspending agent, granules, wettable powder, microcapsules or water dispersible granules.

In a third aspect, the invention claims a bacterial suspension.

The bacterial suspension claimed by the invention is the paenibacillus polymyxa (A)Paenibacillus polymyxa) An bacterial suspension of LQ19, wherein the Paenibacillus polymyxa (R) ((R))Paenibacillus polymyxa) The content of LQ19 is 1.0 × 10⁷～1.0×10¹⁰cfu/mL。

In a fourth aspect, the present invention claims the Paenibacillus polymyxa (B.polymyxa)Paenibacillus polymyxa) Use of LQ19 or the microbial preparation, bacterial manure or the bacterial suspension in any one of:

A1) microbial inoculum or bacterial manure for promoting growth and antagonizing pathogenic bacteria

A2) Bacterium agent or bacterial fertilizer for antagonizing pathogenic bacteria

A3) Bacterial agent or bacterial fertilizer for promoting growth

In a fifth aspect, the present invention claims the Paenibacillus polymyxa: (Paenibacillus polymyxa) The LQ19 or the microbial preparation, the bacterial manure or the bacterial suspension is applied in one or more of broadcasting, root dipping, root irrigation, spraying or sprinkling, seed dressing and seed coating.

In a sixth aspect, the present invention claims the Paenibacillus polymyxa (B.polymyxa)Paenibacillus polymyxa) The LQ19 or the microbial preparation, the bacterial manure or the bacterial suspension is applied to the control of oomycete, fungal and/or bacterial diseases of horticultural crops and field crops such as tomatoes, caraway, celery, strawberries, cucumbers, corns, hot peppers, rapes and the like.

The invention discloses a paenibacillus polymyxa strain (Paenibacillus polymyxa) LQ19 nucleotideThe sequence SEQ ID NO 1 is as follows:

CACTTTTTACCACCTTTCGGCGGCTGGCTCCTTGCGGTTACCTCACCGACTTCGGGTGTTGTAAACTCTCGTGGTGTGACGGGCGGTGTGTACAAGACCCGGGAACGTATTCACCGCGGCATGCTGATCCGCGATTACTAGCAATTCCGACTTCATGTAGGCGAGTTGCAGCCTACAATCCGAACTGAGACCGGCTTTTCTAGGATTGGCTCCACCTCGCGGCTTCGCTTCCCGTTGTACCGGCCATTGTAGTACGTGTGTAGCCCAGGTCATAAGGGGCATGATGATTTGACGTCATCCCCACCTTCCTCCGGTTTGTCACCGGCAGTCTGCTTAGAGTGCCCAGCTTGACCTGCTGGCAACTAAGCATAAGGGTTGCGCTCGTTGCGGGACTTAACCCAACATCTCACGACACGAGCTGACGACAACCATGCACCACCTGTCTCCTCTGTCCCGAAGGAAAGGCCTATCTCTAGACCGGTCAGAGGGATGTCAAGACCTGGTAAGGTTCTTCGCGTTGCTTCGAATTAAACCACATACTCCACTGCTTGTGCGGGTCCCCGTCAATTCCTTTGAGTTTCAGTCTTGCGACCGTACTCCCCAGGCGGAATGCTTAATGTGTTAACTTCGGCACCAAGGGTATCGAAACCCCTAACACCTAGCATTCATCGTTTACGGCGTGGACTACCAGGGTATCTAATCCTGTTTGCTCCCCACGCTTTCGCGCCTCAGCGTCAGTTACAGCCCAGAGAGTCGCCTTCGCCACTGGTGTTCCTCCACATCTCTACGCATTTCACCGCTACACGTGGAATTCCACTCTCCTCTTCTGCACTCAAGCTCCCCAGTTTCCAGTGCGACCCGAAGTTGAGCCTCGGGATTAAACACCAGACTTAAAGAGCCGCCTGCGCGCGCTTTACGCCCAATAATTCCGGACAACGCTTGCCCCCTACGTATTACCGCGGCTGCTGGCACGTAGTTAGCCGGGGCTTTCTTTCTCAGGTACCGTCACCTCCTAGTAG

the paenibacillus polymyxa strain disclosed by the invention has the positive effects that:

(1) the paenibacillus polymyxa strain provided by the inventionPaenibacillus polymyxa) The LQ19 is safe to human, livestock and crops and is environment-friendly.

(2) The paenibacillus polymyxa strain provided by the inventionPaenibacillus polymyxa) The LQ19 has wide bactericidal spectrum and high bacteriostatic activity, can reduce the use amount of chemical pesticides, is beneficial to delaying the generation of drug resistance of pathogenic bacteria, prolongs the service life of the pesticides, reduces the pollution to the ecological environment, improves the food safety and promotes the sustainable development of agriculture.

Drawings

FIG. 1: colony morphology of strain LQ19 on NA medium;

FIG. 2: the inhibitory effect of the strain LQ19 on the growth of pathogenic bacteria hyphae; the solid line box is the control and the dashed line box is the paenibacillus polymyxa treatment. Numbers 1 to 4 are respectivelyRepresentative of Colletotrichum capsici: (Colletotrichum gloeosporioides) Celery stem rot (B)Fusarium oxysporumf. Apiii), tomato Gray leaf spot (germ)Corynespora cassiicola) And cucumber leaf blight bacterium: (Corynespora cassiicola) (ii) a The numbers 5 to 8 represent strawberry blight bacteria respectively: (Fusarium oxysporumf. sp, fragariae), cucumber fusarium wilt bacterium (Fusarium oxysporumf.sp. cucumebrium Owen), coriander root rot (a)F. oxysporumf. sp.coriandrii) And corn phomopsis longissima (C.), (CFusarium graminearum）；

FIG. 3: graph of the effect of seed soaking treatment of strain LQ19 on cucumber growth; left: and B, treating with Paenibacillus polymyxa: carrying out comparison treatment;

FIG. 4: influence of root irrigation treatment of the strain LQ19 on cucumber growth; left: and B, treating with Paenibacillus polymyxa: carrying out comparison treatment;

FIG. 5: the prevention and treatment effect of the strain LQ19 seed soaking on the root rot of caraway is shown; left: and B, treating with Paenibacillus polymyxa: carrying out comparison treatment;

FIG. 6: the effect of spray treatment of the strain LQ19 on controlling cucumber gray mold is shown.

Detailed Description

The present invention will be described in further detail with reference to examples, but the present invention is by no means limited to these examples. The following examples are merely preferred embodiments of the present invention, which are merely illustrative of the present invention and are not to be construed as limiting the scope of the present invention. It should be understood that any modification, equivalent replacement, and improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention. Therefore, the protection scope of the present patent shall be subject to the appended claims.

Unless otherwise indicated, various materials and reagents useful in the present invention are commercially available. Also, the experimental methods used were all conventional methods unless otherwise specified. The invention provides a paenibacillus polymyxa strain, which is named as LQ19 by the applicant and is preserved in China general microbiological culture Collection center (CGMCC) in 2019, 12 and 05 months, and the preservation number is CGMCC No. 19097.

Example 1

Isolation and identification of Paenibacillus polymyxa LQ19

Isolation of Paenibacillus polymyxa strain LQ19

Collecting rhizosphere soil sample from a greenhouse for planting cucumber in Wuqing district of Tianjin, placing the soil sample into a small triangular flask filled with sterile water and sterilized glass beads, and oscillating at 200rpm/min for 20 min; serial gradient dilution of the oscillated suspension 10³、10⁴And sucking 200 mu L of each diluted bacterial suspension, uniformly coating the bacterial suspension with an NA culture medium, culturing at 28 ℃ for 12 hours, picking out a single colony, and carrying out strain purification on the NA culture medium plate by using a plate marking method. One of the isolated and purified strains was named as LQ 19.

Identification of Paenibacillus polymyxa strain LQ19

1. Morphological feature observation

Reference is made to Bergey's Manual of systematic bacteriology (Garrity, 2001) and to general methods of bacteriological characterization (Dongxu bead et al, 2001) in accordance with conventional methods.

The morphological characteristics of paenibacillus polymyxa LQ19 are as follows: the colony surface on the NA culture medium is smooth, milky white, translucent and sticky. The thallus is rod-shaped, and has size of (1.1-2.3) μm × 0.4-0.7 μm. The spores are oval, the cysts are expanded, and the middle growth comes to the terminal growth. Gram staining was positive and flagella were perigenic.

2.16S rDNA sequence amplification and analysis

PCR primers (27F 5 ' -AGAGTTTGATCMTGGCTCAG-3 ' and 1492R 5 ' -TACGGYTACCTTGTTACGACTT-3) synthesized by Tianjin Biotechnology Co., Ltd, Suzhou, 16S rDNA of bacteria was amplified using an Applied Biosystem Veriti PCR apparatus reaction System: 2 × TSINGKE Master Mix 12.5. mu.L, 27F (10pmol/L) 1. mu.L, 1492R (10pmol/L) 1. mu.L, DNA template 1. mu.L, ddH₂And O is supplemented to 25 mu L. And (3) PCR reaction conditions: pre-denaturation at 94 deg.C for 5min, denaturation at 94 deg.C for 30min, annealing at 57 deg.C for 1min, and annealing at 72 deg.CExtension for 1min, final extension for 10min at 72 ℃ for 30 cycles. The PCR amplification product was purified and sequenced by Jinweizhi Biotechnology Ltd, Suzhou (Tianjin). The 16S rDNA sequence of the strain is subjected to sequence comparison analysis in a GenBank nucleic acid sequence database.

The result shows that the detected rDNA sequence part of the paenibacillus polymyxa LQ 1916S has the length of 1019bp, such as SEQIDNO.1. Uploading the sequence to a GeneBank database to obtain GeneBank No. MT645705, and finding the sequence of Paenibacillus polymyxa LQ 1916S rDNA and the sequence of Paenibacillus polymyxa L by BLASTn sequence alignment analysisPaenibacillus polymyxastrain TF2H2 (KY 454473.1) had a similarity of 99.80%.

Example 2

Bacteriostatic action of paenibacillus polymyxa strain LQ19 on 13 pathogenic bacteria

A. Pathogenic bacteria for test

The tested pathogenic oomycetes comprise damping-off tomato bacteria; pathogenic fungi to be tested include Coriolus versicolor root rot, celery stalk rot, strawberry wilt, cucumber wilt, corn stalk rot, cucumber leaf blight, pepper anthracnose, cucumber gray mold, Sclerotinia sclerotiorum, tomato gray leaf spot, and celery leaf spot; the pathogenic bacteria tested included cucumber bacterial angular leaf spot. The test strains are all separated and stored in a seedling disease research laboratory of the plant protection research institute in Tianjin, can be freely provided for the relevant experiments of the invention and cannot be used for other purposes.

B. The test method comprises the following steps:

the method comprises the following steps: the experiment adopts a hypha growth rate method to determine the inhibition effect of the strain LQ19 on pathogenic fungi and pathogenic bacteria, and the inhibition effect is as follows: adding bacterial liquid of the strain LQ19 into the melted PDA to make the final concentration 10⁶cfu/mL, uniformly mixing, pouring into a culture dish, cooling and solidifying the culture medium, inoculating the pathogenic bacteria cake on PDA, treating a bacterial liquid without LQ19 as a blank control, culturing at a constant temperature of 25 ℃, culturing for 24-72h, investigating the growth diameter of each treated pathogenic bacteria, and calculating the inhibition rate. Each treatment was repeated 3 times and averaged.

The second method comprises the following steps: the experiment adopts the inhibition zone to determine the inhibition effect of the strain LQ19 on pathogenic bacteria, specifically as followsThe following: inoculating bacterial pathogenic bacteria on LB culture medium for activation, picking single colony, transferring into 50mL NB culture solution, performing shake culture at 37 deg.C and 170rpm for 2d, diluting with melted NA to 10%⁵cfu/mL, pouring into a sterilized culture dish, inoculating the strain LQ19 of the invention at the central point of the NA plate after solidification, culturing overnight at 37 ℃, measuring the size of the inhibition zone, and calculating the inhibition rate. The results are detailed in table 1, and the photograph of the bacteriostatic test is shown in fig. 2.

TABLE 1 inhibition rate of the bacterial strain LQ19 of the present invention on the growth of pathogenic bacteria hyphae

The results in table 1 show that the strain LQ19 has strong inhibition effect on 13 pathogenic bacteria, the inhibition rate is 73.31% -92.36%, and the disease can be effectively controlled.

Example 3

Influence of the strain LQ19 on cucumber growth

Diluting the suspension agent of the strain LQ19 to 10 percent by using clear water⁷cfu/mL, soaking cucumber seeds for 24h, sowing the soaked seeds in a plastic flowerpot (diameter of 8 cm) filled with nutrient soil, culturing in an illumination incubator at 25 ℃ for 12h, soaking the seeds in clear water for 3 times in a control group, and repeating the steps. After 14d of treatment, the emergence rate, plant height, root length and fresh weight were recorded, as detailed in table 2 and fig. 3.

At 7d after sowing, 5 pots of cucumber seedlings were taken out of the control group and used at a concentration of 10⁷The cucumber seedlings are treated by root irrigation with cfu/mL of the LQ19 strain, the bacterial liquid consumption of each pot is 15 mL, and the emergence rate, the plant height, the root length and the fresh weight are recorded after 7 days of treatment, and the details are shown in Table 2 and figure 4.

Table 2 effect of the strain LQ19 according to the invention on cucumber growth

The results in table 2 show that the germination rate of the strain LQ19 of the invention is improved by 2.31% compared with the control treatment after sowing for 24h when the cucumber seeds are soaked and treated before sowing, and the plant height, root length and fresh weight of a single plant are respectively improved by 12.25%, 45.59% and 26.07% compared with the control treatment (figure 3). After sowing, the roots of the cucumber seedlings are irrigated by using paenibacillus polymyxa at 7d, and the plant height, the root length and the fresh weight of each individual plant of the cucumber seedlings are respectively increased by 21.83%, 67.08% and 39.82% compared with the control treatment after 7d (figure 4). The bacterial strain LQ19 of the invention has a promoting effect on cucumber seed germination through seed soaking treatment, and has a promoting effect on cucumber seedling growth through seed soaking and root irrigation treatment.

Example 4

The bacterial strain LQ19 of the invention has the effect of preventing and treating the root rot of caraway through seed soaking treatment

Diluting the suspension agent of the strain LQ19 to 10 percent by using clear water⁷And (3) soaking seeds of caraway for 24 hours in cfu/mL, then sowing the soaked seeds in a plastic flowerpot (the diameter is 8 cm) filled with bacterial-bearing soil, wherein the bacterial-bearing soil is the soil of a plot where root rot occurs in the field, culturing in a 20 ℃ illumination incubator for 12 hours, and soaking the seeds in sterile water for 3 times in a control group. After 30d of treatment, the emergence and dead seedling conditions are recorded, and the plant height, root length and fresh weight are measured. The control effect is calculated according to the formulas (1) and (2), the data in the table are the average value of 3 repeated treatments, and the test results are detailed in the table 3 and the figure 5.

Table 3 prevention and control effect of the strain LQ19 on root rot of caraway

Table 3 the results show: the strain LQ19 disclosed by the invention is used for soaking seeds of coriander before sowing for 24 hours, the emergence rate of the coriander seeds 30 days after sowing is improved by 15% compared with that of the coriander seeds treated by a contrast, the occurrence of root rot of the coriander is reduced by treating the strain LQ19, and the control effect reaches 74.83%. The strain LQ19 can promote the growth of caraway plants, and the plant height, the root length and the fresh weight of the caraway plants are respectively improved by 16.86 percent, 23.06 percent and 23.81 percent. The strain LQ19 disclosed by the invention can promote the germination of caraway seeds and the growth of seedlings by soaking caraway seeds, and has a better effect of preventing and treating root rot.

Example 5

The prevention and treatment effect of the spray treatment of the strain LQ19 on cucumber diseases

Respectively inoculating the fungus cakes of botrytis cinerea and porphyridium tarkii with the diameters of 4mm to different cucumber seedling leaves, and diluting the wettable powder of the strain LQ19 to the final concentration of 10 by using clear water after inoculating for 24 hours⁷cfu/mL, cucumber leaves were spray treated against clear water treatment, each treatment was repeated 3 times, as detailed in table 4.

TABLE 4 controlling effect of spray treatment of cucumber diseases by the strain LQ19 of the present invention

The results in Table 4 show that the control effect of the spray treatment of the strain LQ19 on the gray mold and the target spot of cucumber is 84.18% and 77.78%, respectively. The bacterial strain LQ19 has better prevention and treatment effects on cucumber gray mold and target spot disease through spray treatment.

Example 6

Preparation of Paenibacillus polymyxa LQ19 bacterial suspension

Culturing purified Paenibacillus polymyxa LQ19 in NB culture medium at 28 deg.C and 120rpm for 48h to obtain seed solution, culturing the seed solution and fermentation culture medium at a volume ratio of 1:100, culturing at 28 deg.C and 120rpm for 48h to produce a large amount of Paenibacillus polymyxa spores, wherein the obtained bacterial suspension contains Paenibacillus polymyxa LQ19 with effective content of 1.0 × 10⁷～1.0×10¹⁰cfu/mL。

Example 7

Preparation of wettable powder of paenibacillus polymyxa strain LQ19

The preparation method comprises the following steps of uniformly mixing paenibacillus polymyxa strain LQ 1930%, carrier white carbon black 60%, sodium dodecyl benzene sulfonate 5%, 2-naphthalene sulfonic acid formaldehyde polymer sodium salt 4.5% and protective agent UV-10.5%, drying in an electrothermal constant-temperature air drying oven at 50 ℃ for 2-3 hours, and finally carrying out superfine grinding by a grinder to prepare wettable powder.

Example 8

Preparation of paenibacillus polymyxa strain LQ19 oil suspending agent

Weighing the components according to the following proportion, wherein the paenibacillus polymyxa strain LQ is 1920%, calcium dodecavancy sulfonate is 8%, nonylphenol polyoxyethylene ether TX-65%, ethylene glycol is 4%, organic bentonite is 2%, and soybean oil is 100% for supplementing. Firstly, adding the organobentonite into the soybean oil, heating to 80 ℃, stirring while heating, stopping heating after dissolution to cool to room temperature, adding other additives, stirring uniformly, then adding the spores, and stirring for 1h to obtain the oil suspending agent.

SEQUENCE LISTING

<110> institute for plant protection in Tianjin

<120> Paenibacillus polymyxa strain and application thereof

<160>1

<170>PatentIn version 3.5

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<211>1019

<212>DNA

<213> Artificial sequence

<400>1

cactttttac cacctttcgg cggctggctc cttgcggtta cctcaccgac ttcgggtgtt 60

gtaaactctc gtggtgtgac gggcggtgtg tacaagaccc gggaacgtat tcaccgcggc 120

atgctgatcc gcgattacta gcaattccga cttcatgtag gcgagttgca gcctacaatc 180

cgaactgaga ccggcttttc taggattggc tccacctcgc ggcttcgctt cccgttgtac 240

cggccattgt agtacgtgtg tagcccaggt cataaggggc atgatgattt gacgtcatcc 300

ccaccttcct ccggtttgtc accggcagtc tgcttagagt gcccagcttg acctgctggc 360

aactaagcat aagggttgcg ctcgttgcgg gacttaaccc aacatctcac gacacgagct 420

gacgacaacc atgcaccacc tgtctcctct gtcccgaagg aaaggcctat ctctagaccg 480

gtcagaggga tgtcaagacc tggtaaggtt cttcgcgttg cttcgaatta aaccacatac 540

tccactgctt gtgcgggtcc ccgtcaattc ctttgagttt cagtcttgcg accgtactcc 600

ccaggcggaa tgcttaatgt gttaacttcg gcaccaaggg tatcgaaacc cctaacacct 660

agcattcatc gtttacggcg tggactacca gggtatctaa tcctgtttgc tccccacgct 720

ttcgcgcctc agcgtcagtt acagcccaga gagtcgcctt cgccactggt gttcctccac 780

atctctacgc atttcaccgc tacacgtgga attccactct cctcttctgc actcaagctc 840

cccagtttcc agtgcgaccc gaagttgagc ctcgggatta aacaccagac ttaaagagcc 900

gcctgcgcgc gctttacgcc caataattcc ggacaacgct tgccccctac gtattaccgc 960

ggctgctggc acgtagttag ccggggcttt ctttctcagg taccgtcacc tcctagtag 1019

Claims

1. A strain of Paenibacillus polymyxa is characterized in that the strain is a Paenibacillus polymyxa strain LQ19 which is preserved in China general microbiological culture Collection center (CGMCC) in 2019, 12 months and 05 days, wherein the preservation number is CGMCC NO. 19097; the Paenibacillus polymyxa strain (A)Paenibacillus polymyxa) The nucleotide sequence of LQ19 is shown in SEQ ID NO. 1.

2. The application of the paenibacillus polymyxa strain LQ19 in preventing and treating rhizome rot and leaf diseases of horticultural crops and field crops or in preparing microbial bacteriostat or bacterial manure for diseases.

3. Use according to claim 2, wherein the disease is an oomycete, fungal and/or bacterial pathogen.

4. The use of claim 3, wherein the oomycete disease is tomato damping off; the fungal pathogenic bacteria are selected from one or more than two of the following pathogenic bacteria: coriolus versicolor root rot, celery phomopsis, strawberry blight, cucumber blight, corn phomopsis, cucumber leaf blight, pepper anthracnose, cucumber gray mold, sclerotinia sclerotiorum, tomato gray leaf spot, and celery leaf spot; the bacterial pathogenic bacteria are cucumber bacterial angular leaf spot.

5. The paenibacillus polymyxa strain LQ19 of claim 1 can be prepared into a microbial agent, which comprises fermentation liquor, a liquid microbial agent, a solid microbial agent or a bacterial fertilizer, wherein the bacterial concentration of the paenibacillus polymyxa is 1 × 10⁷~1×10¹⁰cfu/g。

6. The method for producing a microbial agent according to claim 5, wherein: carrying out shake culture on the purified paenibacillus polymyxa LQ19 in an NB culture medium for 48h at 28 ℃ and 120rpm to obtain a seed solution, carrying out amplification culture according to the volume ratio of the seed solution to the fermentation culture medium of 1:100, and carrying out shake culture at 28 ℃ and 120rpm for 48h to obtain a culture which is a fermentation broth; centrifuging the fermentation liquor at 10000rpm for 10min, collecting thalli, resuspending the thalli in sterile water, and adding an antifreezing agent, a stabilizing agent, a dispersing agent and an emulsifier auxiliary agent to obtain a liquid microbial inoculum; adding auxiliary agents such as a carrier, a dispersing agent, a wetting agent and the like into the bacterial liquid, uniformly mixing, carrying out ultramicro airflow crushing, mixing, granulating, drying and screening to obtain the solid microbial inoculum.

7. The method for preparing microbial fertilizer of claim 6, wherein the bacterial fertilizer is prepared by mixing and fermenting the auxiliary materials of grass carbon, crop straws, rice hulls, animal wastes and paenibacillus polymyxa LQ 19.

8. The use as claimed in claim 2, wherein the crop is selected from one or more of tomato, caraway, celery, strawberry, cucumber, corn, pepper and rape.

9. The microbial inoculant according to claim 5, wherein any one of the inoculants can be applied by one or more of broadcasting, dipping, drenching, spraying or sprinkling, dressing, and coating.

10. The microbial inoculum of claim 5 for promoting seed germination, increasing plant height, root length and fresh weight of crops.