CN106754536B

CN106754536B - Bacillus circulans Y3 and application thereof in preventing and treating crop soil-borne diseases

Info

Publication number: CN106754536B
Application number: CN201611266952.3A
Authority: CN
Inventors: 范丙全
Original assignee: Institute of Agricultural Resources and Regional Planning of CAAS
Current assignee: Institute of Agricultural Resources and Regional Planning of CAAS
Priority date: 2016-12-31
Filing date: 2016-12-31
Publication date: 2020-04-10
Anticipated expiration: 2036-12-31
Also published as: CN106754536A

Abstract

The invention provides a bacillus circulans Y3 and application thereof in preventing and treating crop soil-borne diseases. The collection number of the bacillus circulans Y3 is CGMCC NO.13511, the bacillus circulans Y3 is prepared into a microbial agent, has obvious prevention and treatment effects on sunflower soil-borne diseases such as sclerotinia sclerotiorum and rust, has obvious growth promotion effect on crops such as corn, tomato, rape, sunflower and the like, has no inhibition on the yield increasing and disease preventing effects by using a chemical fertilizer, and can be used for continuously increasing the yield under the normal use condition of the chemical fertilizer. The bactericide has the effects of preventing and treating the diskal rot caused by the sunflower sclerotinia by over 95 percent, preventing and treating the rust by 100 percent and increasing the yield of the sunflower by 20 to 50 percent, and pot experiment results show that the bactericide promotes the growth of crops and improves the biomass by 15 to 70 percent. The microbial inoculum has important significance for preventing and treating soil-borne diseases of farmlands, increasing grain yield continuously and protecting the ecological environment of farmlands in China.

Description

Bacillus circulans Y3 and application thereof in preventing and treating crop soil-borne diseases

Technical Field

The invention relates to the technical field of microbiology and plant disease biocontrol, in particular to a bacillus circulans Y3 and application thereof in preventing and controlling crop soil-borne diseases.

Background

With the improvement of the crop yield level and the development of facility agriculture, the problems of soil-borne diseases and continuous cropping obstacles are prominent day by day, and the soil pathogenic microorganisms are increased continuously, so that the yield of crops is reduced and even the crops are no longer harvested. Soil-borne diseases and continuous cropping obstacles have become bottlenecks in the development of agricultural safety production. The yield of the crops is reduced by 10-20% in 3 years of continuous cropping, and the yield of the crops is reduced by 40-50% in 4-5 years of continuous cropping. Greenhouse vegetable, potato, garlic, sunflower, rape, cotton, soybean, rice, wheat and beet soil-borne diseases occur frequently, the yield is reduced day by day seriously, and the yield and income of farmers are influenced. The area of China suffering from serious soil-borne diseases and continuous cropping obstacle is as high as 5 hundred million acres.

Because soil-borne diseases are aggravated, the amount of pesticides used in China per year exceeds 130 million tons, the usage amount of the pesticides generally exceeds the standard, and 931.3g of pesticides are applied to each mu on average and are twice as much as developed countries. The agricultural land polluted by pesticide in China is about 1600 million hectares, and the overproof rate of pesticide residue in main agricultural products is as high as 20%. The technology for preventing and controlling soil-borne diseases is not effectively solved, and biological prevention and control of the soil-borne diseases is the best choice for replacing chemical pesticides.

The strains for biologically preventing and treating soil-borne diseases are mostly trichoderma, streptomycete, pythium oligandrum, spore bacteria and the like. Microbial inoculant products for controlling soil-borne diseases, commercially available products such as K84 in australia and K84 in bacillus radiobacter strains were produced on a large scale in 1973 for the control of root cancer; gustafson corporation registered in the United states in 1988 to produce Kodiak, a product A13, and became a pioneer in the commercial production of biocontrol bacteria for crops. Fungicidal preparation produced by using pseudomonas fluorescens (p. fluorescens CHA0)

Yield

Can prevent and treat soil fungal diseases. Product produced by Serratia plymuthica HRO-C48

And produced by actinomycetes (Streptomyces sp. HRO-71)

Preventing and treating strawberry and potato Verticillium dahliae (Verticillium dahliae). Trichoderma reesei G1 and Trichoderma viride G3 for preventing and treating damping-offThe effect is obvious.

Topshield (Trichoderma harzianum T22) developed in the United states and Trichoderma harzianum (Trichoderma harzianum T39) developed in Israel are both used for controlling fungal diseases such as gray mold and a commercial preparation Trichoderma2000 developed by Mycontrol corporation in Israel is mainly used for controlling Rhizoctonia solani, Sclerotium rolfsii, Phytophthora blight, etc.; the coniothyrium minitans is also a biological control bacterium which is researched more, and has strong inhibition effect on various plant diseases caused by sclerotinia and sclerotinia virescens. At present, commercial products are available abroad, for example, the commercial preparation Coniothyrin developed by the former Soviet Union can be used for preventing and treating sclerotinia sclerotiorum of sunflower, and the commercial preparation ntansWG developed by Germany can be used for preventing and treating sclerotinia sclerotiorum of lettuce and the like. In addition, SoilGard, which is developed successfully from the United states against Gliocladium virens (Gliocladium virens), is used for preventing and treating damping-off, root rot and the like, and BiofoxC, which is developed in Italy, is specially used for preventing and treating fusarium diseases and the like. The commercial trichoderma fungicide (named as bactericide) in China is mainly used for preventing and treating downy mildew of various crops, and 5406 developed antibiotic bacteria in China are streptomyces, named as streptomyces jingyangensis, have resistance to a plurality of plant diseases such as verticillium wilt bacteria, fusarium wilt bacteria, rhizoctonia solani and damping-off bacteria, and can promote plant growth. The large-area demonstration and popularization test of antagonistic bacteria (Bacillus subtilis) proves that the antagonistic bacteria have strong field planting capability on rice plants and rapid propagation, and the prevention effect on the sheath blight reaches 75-85 percent, and the prevention effect on the false smut reaches 63.8-85.7 percent. Antagonistic trichoderma and antagonistic bacteria are mixed and fermented to prepare powder, so that the seedling diseases of protected vegetables and melons are successfully prevented and controlled. Other reported bacterial bactericides are used for preventing and treating bacillus licheniformis of anthracnose of cucumber and tobacco, bacillus subtilis for preventing and treating sugarcane black rot, pseudomonas radiobacter for preventing and treating wheat take-all and the like. The trichoderma chlamydospore preparation has the control effect of 60 percent on the large-area test of verticillium wilt of Xinjiang cotton, the yield is increased by 50 percent, the cotton linter length is increased by 10 percent, and the trichoderma chlamydospore preparation shows good application prospect.

The sunflower has the characteristics of saline-alkali resistance, barren tolerance, strong drought resistance adaptability and the like, the oil content of seeds is high, the oil quality is excellent, and the sunflower is the 4 th oil crop in the world. 2002 global sunflower plantingArea 2600 ten thousand hm²The yield of the sunflower seeds is 2400 ten thousand tons. The global sunflower seed production in 2014, 2015 is reported to be 1551.9 ten thousand t. The area of sunflower in 2004 China is 113.1 kilohm²The total yield is 194.6 ten thousand tons, and the sunflower sowing area in China is 102 ten thousand hm in 2007²The total yield is 192.8 ten thousand t, and the yield per unit is 1889.3 kg/ha.

Continuous cropping of sunflower results in excessive consumption of soil nutrients, particularly potassium, and difficult recovery of soil fertility. Sunflower diseases such as sclerotinia, rust, brown spot, downy mildew and leaf blight, as well as Heliothis incertulas, Tabanus, cutworm and the like are all aggravated by continuous cropping. Sunflower sclerotinia rot, also known as white rot and rotten disc disease, has a great influence on the yield and quality of sunflower.

Sunflower sclerotiniose is widely and seriously attacked, and can cause stem folding, flower disc and kernel rot of the sunflower, thereby causing serious threat to sunflower production. The common types are 4 types of root rot type, stem rot type, leaf rot type and flower rot type, wherein the damage of the root rot type and the flower rot type is serious. The flower rot type disease is characterized in that after a flower disc is damaged, water-immersed disease spots appear on the back of the disc.

At present, the method mainly comprises the steps of using ①% of rhizoctonia solani 800-1000 times of liquid, using ②% of thiophanate 1000 times of liquid, using ③% of prochloraz 500-1000 times of liquid, using the pesticide preparation for preventing and treating, wherein the pesticide preparation has a not ideal prevention and treatment effect which is only about 80%, and therefore, the research and development of the biological fertilizer for preventing and treating soil-borne diseases and continuous cropping obstacles are very important.

Disclosure of Invention

The invention aims to provide a bacillus circulans Y3 for efficiently preventing and treating sclerotinia and rust of sunflower and a microbial agent prepared by the bacillus circulans Y3, aiming at the production problems of frequent occurrence, serious yield reduction and even no harvest of sclerotinia and rust of sunflower caused by continuous cropping in China.

The invention also aims to provide application of the bacillus circulans Y3 in preventing and treating crop soil-borne diseases.

In order to realize the purpose, the invention obtains a Bacillus circulans Y3 for efficiently preventing and treating sunflower sclerotinia and rust by separating and purifying from farmland soil of princess ridge in Jilin province of China, which is deposited in the common microorganism center of China Committee for culture Collection of microorganisms, No. 3 of Xilu No.1 of Shanggong district in Beijing City, the institute of microbiology of China academy of sciences, zip code 100101, preservation number CGMCC NO.13511 and preservation date 2016, 12 months and 28 days.

According to the bacteriological characteristics of the strain Y3 and the sequencing result of 16S rDNA (SEQ ID NO:1), the strain Y3 is determined to be the bacillus circulans.

The invention also provides a microbial agent containing the bacillus circulans Y3.

The microbial inoculum also contains an additive and a protective agent.

Wherein the additive is at least one of silicon dioxide, light calcium carbonate, kaolin, bentonite, rice hull powder, wheat hull powder, straw powder and the like.

The protective agent is at least one of glycerol, skimmed milk, vegetable oil, sodium alginate, chitosan, etc.

The microbial inoculum provided by the invention comprises the following components in parts by weight:

1 part of bacillus circulans Y3 fermentation liquor;

0.5-3 parts of an additive;

0.01-0.05 part of protective agent;

the number of the live bacteria of the bacillus circulans Y3 in the microbial inoculum is 2 multiplied by 10⁸-5×10⁹cfu/g, preferably 5X 10⁸cfu/g。

The invention also provides application of the bacillus circulans Y3 or the microbial inoculum in preventing and treating crop soil-borne diseases (sunflower sclerotinia rot, sunflower rust disease and greenhouse vegetable continuous cropping obstacle).

The pathogenic bacteria of the soil-borne diseases comprise sclerotinia sclerotiorum, puccinia helianthus, fusarium oxysporum and the like.

The invention also provides application of the bacillus circulans Y3 or the microbial inoculum in improving crop yield.

The crops comprise greenhouse vegetables. Preferably, the crops include sunflower, garlic, corn, rape, tomato, etc.

The invention also provides application of the bacillus circulans Y3 or the microbial inoculum in preparation of an agricultural compound fertilizer.

The invention also provides an agricultural compound fertilizer which consists of a microbial inoculum with the effective component of the bacillus circulans Y3 and a nitrogenous fertilizer, a phosphate fertilizer, a potash fertilizer or a compound fertilizer.

The microbial agent with the effective component of the bacillus circulans Y3 has obvious growth promoting and yield increasing effects on field sunflowers, is not inhibited by field soil conditions and fertilizer use, and can be applied together with fertilizer in mild saline-alkali farmlands. The bactericide has the effects of preventing and treating the diskal rot caused by the sunflower sclerotinia by over 95 percent, preventing and treating the rust by 100 percent, increasing the yield of the sunflower by 20 to 30 percent and increasing the yield of the sunflower by 20 to 50 percent, and pot experiment results show that the bactericide promotes the growth of crops and increases the biomass by 15 to 70 percent. The microbial agent has important significance for preventing and treating soil-borne diseases and continuous cropping obstacles of farmlands in China, increasing grain yield continuously and protecting the ecological environment of the farmlands.

Drawings

FIG. 1 is a graph showing the effect of the strain Y3 on the inhibition of Fusarium oxysporum on plates in example 9 of the present invention; wherein A, B represents the obverse and reverse sides of PDYA plates in which Y16 inhibits Fusarium oxysporum, respectively.

Detailed Description

The following examples are intended to illustrate the invention but are not intended to limit the scope of the invention. Unless otherwise specified, the technical means used in the examples are conventional means well known to those skilled in the art, and the raw materials used are commercially available products.

Example 1 preparation of Bacillus circulans Y3 inoculum

1. Isolation and purification of Bacillus circulans Y3

A strain Y3 for efficiently preventing and treating sunflower sclerotinia rot and rust disease is obtained by separating and purifying soil from farmland of princess ridge of Jilin province in China.

2. Culture of Bacillus circulans Y3

(1) Composition of the Medium (kg/t broth)

10kg of soluble starch, 10kg of soybean cake powder, 5kg of corn flour, 1kg of glucose, 10kg of sucrose, 5kg of yeast powder, (NH)₄)₂SO₄3kg，K₂HPO₄0.2kg，NaCl 2.5kg，MgSO₄·7H₂O 0.1kg，CaCO₃0.5kg，FeSO₄0.001kg, 1L boric acid (1%), pH7.0, made up with water.

(2) Fermentation culture process

Inoculating Bacillus circulans Y3 on potato sucrose (PDA) culture medium, and culturing at 25-28 deg.C for 3 days. Transferring the bacillus circulans Y3 into a 1000mL triangular flask, and carrying out liquid fermentation culture at 26-28 ℃ and 220r/min for 36 h. Then inoculating into a 50L seed tank according to the inoculum size of 1 percent, culturing for 36h under the conditions of 200r/min, pH7.0 and ventilation capacity of 0.7vvm, then transferring into a 500L fermentation tank according to the inoculum size of 10v/v percent, and culturing for 3d under the conditions of 220r/min, pH7.0 and ventilation capacity of 0.7-1.0 vvm.

3. Preparation of Bacillus circulans Y3 microbial inoculum

After fermentation, sodium alginate as a protective agent is added, and bacillus circulans Y3 is adsorbed by light calcium carbonate.

4. Granulating by using bacillus circulans Y3 microbial inoculum

Adding appropriate amount of rice hull powder, straw powder and bentonite into the adsorbed and mixed microbial inoculum, performing binding granulation, and granulating according to production requirement to obtain granular microbial inoculum (viable count of 5 × 10) suitable for sunflower⁸cfu/g) applied to the soil together with a sunflower seed planter; or a granulator is used for forming granular biological fertilizer with the grain size similar to that of the urea, the diammonium phosphate, the potash fertilizer and the compound fertilizer, and the biological fertilizer, the urea, the diammonium phosphate, the potash fertilizer and the compound fertilizer are mechanically applied to soil together.

Example 2 growth promoting Effect of Bacillus circulans Y3 inoculum on potted maize

1. The inoculation test of the Y3 microbial inoculum is carried out under the greenhouse condition, and the soil is from the soil of farmland of Tangjialing. Corn is planted under the potting condition, and biological fertilizer inoculants prepared by 2 strains are respectively inoculated. Treatments were CK, ACCC10094 and Y3, respectively, and strain ACCC10094 was a potassium-resolving bacterium as a control strain. The results show that the ACCC10094 and Y3 strains both have the effect of promoting crop growth and can increase the biomass of corn (table 1). The fresh weight biomass of corn processed by the strains ACCC10094 and Y3 respectively reaches 16.2 g/pot and 18.4 g/pot, and is respectively improved by 28.6 percent and 46.0 percent compared with the control; the dry weight biomass of the strains ACCC10094 and Y3 respectively reach 1.504 g/pot and 1.8626 g/pot, and are respectively improved by 13.5 percent and 40.6 percent compared with the control. The Y3 strain has the highest corn biomass, which shows that the effect of promoting the corn growth is obvious.

TABLE 1 Effect of Y3 inoculum on potted maize Biomass

Note: a. b, c indicate significant differences between treatment groups.

Example 3 growth promoting Effect of Y3 microbial inoculum on potted rape

The pot experiment soil is from farmland soil of Tangjialing, rape is planted under the pot condition, and biological fertilizer microbial inoculum prepared by ACCC10094 and Y3 strains are respectively inoculated. The fresh weight of the biomass of the rape inoculated with the ACCC10094 and Y3 bactericides reaches 5.475 g/pot and 7.66 g/pot respectively, and is improved by 73.3 percent and 142.4 percent respectively compared with the control; the ACCC10094 and Y3 inoculants are inoculated, the dry weight of the rape biomass is 1.036 g/pot and 1.276 g/pot respectively, and the dry weight is respectively increased by 38.9% and 71.0% compared with the control. The microbial inoculum prepared by the Y3 strain obviously improves the biomass of the rape.

TABLE 2 Effect of Y3 inoculum on Biomass of potted Brassica campestris

Note: a. b, c indicate significant differences between treatment groups.

Example 4 growth promoting Effect of Bacillus circulans Y3 inoculum on potted tomatoes

Sunflower is planted under potting conditions, and 2 biological fertilizer inoculants are respectively inoculated, wherein the inoculants are prepared from Y3 and ACCC 40120. The results of the experiments show that 2 microbial agents are capable of increasing the biomass of tomatoes (table 3). The biomass of the Y3 microbial inoculum is the highest, the fresh weight and the dry weight respectively reach 55.40 g/pot and 7.69 g/pot, and are respectively increased by 46.5 percent and 15.5 percent compared with a control; the fresh and dry weights of ACCC40120 were lower than Y3, 43.89 g/pot and 7.54 g/pot, respectively, 16.1% and 13.3% higher than the control, respectively. The Y3 microbial inoculum has a remarkable effect of promoting the growth of the sunflower.

TABLE 3 Effect of Y3 inoculum on Biomass of potted tomatoes

Note: a. b, c indicate significant differences between treatment groups.

Example 5 growth promoting Effect of Y3 microbial inoculum on potted garlic

The garlic is planted under the potting condition, and 2 biological fertilizer inoculants are respectively inoculated, and the result shows that the biomass of the garlic can be obviously increased by applying the inoculants, compared with a control (without the inoculants), the biomass of the Y3 microbial inoculum reaches 7.09 g/pot, is averagely increased by 2.18 g/pot, and is increased by 44.4%; the biomass of the AS1.1216 strain reaches 6.14 g/pot, the biomass is increased by 1.23 g/pot, and the biomass is increased by 25.1 percent compared with the control. Y3 showed a significant growth promoting effect (table 4).

TABLE 4 influence of Y3 microbial inoculum on biomass of potted garlic

Note: a. b, c indicate significant differences between treatment groups.

Example 6 growth promoting Effect of Y3 microbial inoculum on potted Helianthus annuus

Growth promoting effect of Y3 microbial inoculum on potted non-saline-alkali soil sunflower

An inoculation test of the Y3 microbial inoculum is carried out under a greenhouse condition, soil is from soil of a farmland before Mengmuir Wulart, sunflowers are planted in successive years, and sclerotinia and rust diseases are abnormally serious. Planting sunflower under potting condition, and respectively inoculating 3 biological fertilizer inocula prepared from Y3 and DSM 8785 DSM 1732. The results of the experiments show that 3 microbial agents are able to increase the biomass of sunflower (table 5). The biomass of the Y3 microbial inoculum is the highest, the fresh weight of the biomass reaches 9.92 g/pot, and is improved by 117.54 percent compared with the control; the DSM 8785 microbial inoculum is lower than Y3, the fresh weight reaches 6.47 g/pot, and is increased by 41.89% compared with the control; DSM1732 microbial inoculum biomass was the lowest, only 27.85% higher than the control. The Y3 microbial inoculum has obvious effect of promoting the growth of the sunflower.

TABLE 5 Effect of biofertilizer on sunflower Biomass in non-saline soil under potting conditions

Note: a. b and c show that the difference between the treatment groups is significant, and bc shows that the difference between the treatment group and the treatment groups of b and c is not significant.

Growth promoting effect of Y3 microbial inoculum on potted light saline-alkali soil sunflower

An inoculation test of a bacillus circulans Y3 microbial inoculum is carried out under a greenhouse condition, test soil is from the ancient flag of the Mengming Wulart, is slightly saline and alkaline, and sunflower is planted in successive years, and sclerotinia and rust are abnormally serious. Under potting conditions, 4 biofertilizer inoculants were inoculated to sunflower, which were prepared from Y3, DSM 40006, DSM 10690 and AS1.1216 strains, respectively. The results show that all microbial agents can increase the biomass of sunflower, and the fresh biomass weights of the Y3, DSM 40006, DSM 10690 and AS1.1216 agents are 7.46 g/pot, 7.35 g/pot, 7.23 g/pot and 7.08 g/pot respectively, which are 21.9%, 20.1%, 18.14% and 15.69% respectively higher than the control 6.12 g/pot. The Y3 microbial inoculum has the highest sunflower biomass and the best yield increasing effect, which shows that the Y3 microbial inoculum has obvious effect of promoting the growth of the sunflowers. However, it is not difficult to see that Y3 has a lower growth promoting effect on sunflower than non-saline soil. (Table 6)

TABLE 6 Effect of biofertilizer on Biomass of sunflower in Mild saline-alkali soil under potting conditions

Note: a. b indicates significant differences between treatment groups.

Example 7 Effect of Y3 inoculum on yield of sunflower in the field

The field test was carried out on the inner Mongolia Wulat front flag, the crop was sunflower, the variety was LDS 009. The usage amount of the microbial inoculum is 60 kg/mu, and the usage amount of the nitrogen-phosphorus-potassium compound fertilizer (15-15-15) particles is 40 kg/mu. The results show that no disease occurs to sunflower during the whole growth period, neither sclerotinia nor puccinia occurs, and the disease caused by sclerotinia and puccinia of sunflower in peripheral farmland is serious. The field test result shows that the yield of the bacillus circulans Y3 is the highest, the yield per mu is 259.3 kg, and the yield is increased by 21.7%; the yield of the actinomycetes AS1.1216 is 247.6 kilograms per mu, and the yield is increased by 16.2 percent. The acre yield of the ACCC 11079 bacterial agent reaches 225.5 kilograms, and the yield is increased by 5.9 percent; DSM 2573 yields 220.4 kg per mu, and increases the yield by 3.5%. Indicating that Y3 has good stimulation potential (table 7).

TABLE 7 Effect of Bacillus circulans Y3 inoculum on sunflower production

Note: a. b indicates significant differences between treatment groups.

Example 8 yield increase of sunflower in field by different amounts of Y3 microbial inoculum

The field test mainly researches the best matching effect of the biological fertilizer and the common diammonium phosphate, and fully plays the maximum role of the biological fertilizer and the chemical fertilizer. Diammonium phosphate is arranged at three levels, namely 30 kg/mu, 40 kg/mu and 50 kg/mu respectively; the biofertilizer is set to 4 levels, which are respectively 0, 33.3, 66.7 and 100 kg/mu; all treatments were repeated 3 times. The results show that 4 levels of Bacillus circulans Y3 inoculum increased sunflower production at different fertilizer dosages (Table 8). The three fertilizers have different dosage and effect, so that the yield increasing effect of the biological fertilizer microbial inoculum is best under the condition of using 40 kg/mu of diammonium phosphate, and the yield of the sunflower is improved along with the increase of the dosage of the biological fertilizer; the yield of the inoculated Y3 microbial inoculum is 33.3, 66.7 and 100 kg/mu, is increased by 17.7 percent, 48.3 percent and 66.8 percent respectively compared with the control, and is obviously higher than the yield increase effect of the microbial inoculum treatment of the corresponding biological fertilizer with 30 kg/mu of diammonium phosphate. In order to avoid waste of chemical fertilizers, 66.7-100 kg/mu of biological fertilizer microbial inoculum and 40 kg/mu of diammonium phosphate are used as the optimal combination.

TABLE 8 Effect of Bacillus circulans Y3 biofertilizer on yield of sunflower in the field

Note: a. b, c, d indicate significant differences between treatment groups.

Example 9 Effect of Y3 Strain plates on inhibition of Fusarium oxysporum

In order to verify the ability of Y3 to antagonize pathogenic fungi, Fusarium oxysporum (ACCC36241) was inoculated in the center of a PDYA medium plate on PDYA medium, the periphery of the pathogenic fungi was evenly divided into 4 points, and four strains No.1, No. 2, No. 3 and No. 5 were inoculated, wherein the strains No.1, No. 2 and No. 5 were Bacillus and the colony No. 3 was Y3. The results show that the pathogen inoculated at the site of Y3 is inhibited, demonstrating the ability of Y3 to inhibit the growth of filamentous pathogenic fungi (FIG. 1).

To verify the ability of Y3 to antagonize pathogenic fungi, fusarium oxysporum (ACCC36241) was inoculated into the center of PDYA media plates and evenly divided into 4 spots around the pathogen, 3 of which were inoculated with Y16 bacteria and the other spot was not inoculated with Y3 as a control. The results show that the 3-point pathogen inoculated with Y3 was inhibited, whereas the F.oxysporum colonies not inoculated with Y3 grew faster. Y3 was shown to have the ability to inhibit the growth of Fusarium oxysporum. (FIG. 1)

The invention researches the efficient antagonistic bacterium Y3 for antagonizing the sclerotinia rot and the rust disease of the sunflower and preventing and treating the continuous cropping obstacle of greenhouse vegetables and the microbial agent thereof in many aspects, and the microbial agent can prevent and treat the sclerotinia rot and the rust disease of the sunflower, prevent and treat the continuous cropping obstacle of the greenhouse vegetables and improve the crop yield. The developed Y3 microbial agent for disease resistance and yield increase shows great application prospect.

Although the invention has been described in detail hereinabove with respect to a general description and specific embodiments thereof, it will be apparent to those skilled in the art that modifications or improvements may be made thereto based on the invention. Accordingly, such modifications and improvements are intended to be within the scope of the invention as claimed.

Sequence listing

<110> institute of agricultural resources and agricultural regionalism of Chinese academy of agricultural sciences

<120> Bacillus circulans Y3 and application thereof in preventing and treating crop soil-borne diseases

<130>KHP161119385.4Q

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<170>PatentIn version 3.3

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<213> Bacillus circulans

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gaaaccggag ctaataccgg ataatccttt tcctctcatg aggaaaagct gaaagacggt 180

ttacgctgtc acttacagat gggcccgcgg cgcattagct agttggtgag gtaacggctc 240

accaaggcga cgatgcgtag ccgacctgag agggtgatcg gccacactgg gactgagaca 300

cggcccagac tcctacggga ggcagcagta gggaatcttc cgcaatggac gaaagtctga 360

cggagcaacg ccgcgtgagt gatgaaggtt ttcggatcgt aaaactctgt tgttagggaa 420

gaacaagtac aagagtaact gcttgtacct tgacggtacc taaccagaaa gccacggcta 480

actacgtgcc agcagccgcg gtaatacgta ggtggcaagc gttgtccgga attattgggc 540

gtaaagcgcg cgcaggcggt cctttaagtc tgatgtgaaa gcccacggct caaccgtgga 600

gggtcattgg aaactggggg acttgagtgc agaagagaag agtggaattc cacgtgtagc 660

ggtgaaatgc gtagagatgt ggaggaacac cagtggcgaa ggcgactctt tggtctgtaa 720

ctgacgctga ggcgcgaaag cgtggggagc aaacaggatt agataccctg gtagtccacg 780

ccgtaaacga tgagtgctaa gtgttagagg gtttccgccc tttagtgctg cagcaaacgc 840

attaagcact ccgcctgggg agtacggccg caaggctgaa actcaaagga attgacgggg 900

gcccgcacaa gcggtggagg 920

Claims

1. Bacillus circulans Y3 with preservation number CGMCC NO. 13511.

2. A microbial inoculant comprising Bacillus circulans Y3 of claim 1.

3. The microbial inoculum according to claim 2, which also contains additives and protective agents;

wherein the additive is at least one of silicon dioxide, light calcium carbonate, kaolin, bentonite, rice hull powder, wheat hull powder and straw powder;

the protective agent is at least one of glycerol, skimmed milk, vegetable oil, sodium alginate and chitosan.

4. The microbial inoculum according to claim 3, which is prepared from the following components in parts by weight:

1 part of bacillus circulans Y3 fermentation liquor;

0.5-3 parts of an additive;

0.01-0.05 part of protective agent;

the number of the live bacteria of the bacillus circulans Y3 in the microbial inoculum is 2 multiplied by 10⁸-5×10⁹cfu/g。

5. A use of Bacillus circulans Y3 as claimed in claim 1 or a microbial inoculum as claimed in any one of claims 2 to 4 in controlling soil-borne diseases of crops.

6. The use as claimed in claim 5, wherein the pathogenic bacteria of soil-borne diseases include sclerotinia, puccinia helianthi, fusarium oxysporum.

7. Use of Bacillus circulans Y3 as claimed in claim 1 or a bacterial agent as claimed in any one of claims 2 to 4 for increasing crop yield.

8. The use of claim 7, wherein the crop comprises a greenhouse vegetable.

9. Use according to claim 8, wherein the crop comprises sunflower, garlic, maize, rape, tomato.

10. Use of a Bacillus circulans Y3 as claimed in claim 1 or a bacterial agent as claimed in any one of claims 2 to 4 in the preparation of an agricultural compound fertilizer.

11. An agricultural compound fertilizer, which is characterized by consisting of the microbial inoculum of any one of claims 2 to 4 and a nitrogenous fertilizer, a phosphate fertilizer, a potash fertilizer or a compound fertilizer.