CN102747005B - Bacillus atrophaeus for prevention and control of cotton boll blight, and microbial agent thereof - Google Patents

Abstract

The invention discloses a Bacillus atrophaeus strain HMB22922 for preventing and treating cotton boll blight, which was preserved in China Microorganism Culture Collection and Management Center on December 20, 2011, and the preservation number is CGMCC No.5614. The invention also discloses a microbial bacterial agent produced by the bacterial strain and a preparation method thereof. The active ingredients of the bacterial agent are HMB22922 bacterial cells and its extracellular metabolites. The HMB22922 bacterial strain of the present invention has a specific control effect on cotton boll blight, and the control effect is high, with an average control effect of more than 80%; secondly, the microbial agent of the present invention is safe for humans and animals, and has no environmental pollution problem; and the use of the present invention to prevent and control cotton bolls Epidemic diseases are not easy to produce drug resistance; in addition, the preparation method of the microbial agent of the present invention is simple, low in cost and convenient to use.

Description

A kind of Bacillus atrophaeus and its microbial agent for preventing and treating cotton boll blight

technical field

The invention belongs to the field of agricultural microorganisms, and in particular relates to a bacillus atrophaeus for preventing and treating cotton boll blight, a microbial agent containing the bacillus atrophaeus, and their application in preventing and treating cotton boll blight. the

Background technique

Cotton boll blight is a serious cotton disease caused by Phytophthora boehmeriae sawada, which not only directly damages cotton bolls, but also provides infection conditions for other pathogens. The methods to prevent and control cotton boll blight are mainly cultivation measures such as pushing plants and ridges, picking rotten bolls early, and chemical agent control. At present, the economic benefits of growing cotton in my country are relatively low, and the labor costs are high. Farmers are unwilling to invest too much energy in pushing the plants together; picking rotten bolls early can only keep part of the yield, which is not enough to prevent and control cotton boll blight; The effect is better, but there are problems such as easy to produce drug resistance, expensive chemical agents, increased production costs, and environmental pollution. Therefore, it is urgent to find a time-saving, labor-saving, efficient and low-cost prevention method. the

The use of beneficial microorganisms to carry out biological control of plant diseases has attracted more and more attention due to its advantages of strong pertinence, high control efficiency and environmental protection. Especially it is widely used in vegetable air-borne diseases and crop soil-borne diseases. There are few studies on biological control of cotton boll blight. Ma Ping (Ma Ping. Biological Control Bulletin. 1993.9 (3)) found that Trichoderma and Pythium have a certain control effect on cotton boll blight, and screened biocontrol bacteria MB-3 and MB-7, and 10 times dilution of their fermentation broth Field control effects on cotton boll blight were 34.9% and 45.4% respectively (Ma Ping. Biological Control of China. 1998.14 (2)). the

Bacillus (Bacillus) has the advantages of wide distribution, easy isolation and culture, the ability to produce spores with strong stress resistance, long storage period and convenient use. It is an ideal biocontrol microorganism. Compared with other types of biocontrol factors, It is more conducive to the production of bacterial agents, formulation processing, survival, colonization and reproduction in the environment. Therefore, screening for bacillus that has an inhibitory effect on pathogenic bacteria is one of the most effective methods for preventing and controlling related plant diseases. the

Contents of the invention

The purpose of the present invention is to provide a bacillus atrophaeus strain for preventing and treating cotton boll blight, which has the advantages of high efficiency, broad-spectrum bactericidal activity and the like. the

The second object of the present invention is to provide a microbial inoculation agent. the

The third object of the present invention is to provide the preparation method of the above-mentioned microbial inoculum. the

The fourth object of the present invention is to provide the use of the above-mentioned Bacillus atrophaeus strain in the prevention and treatment of cotton boll blight. the

The fifth object of the present invention is to provide the use of the above-mentioned microbial agent in the prevention and treatment of cotton boll blight. the

The present invention is realized through the following technical solutions:

A strain of Bacillus atrophaeus (Bacillus atrophaeus) HMB22922 has been preserved in the General Microbiology Center of the China Committee for the Collection of Microbial Cultures on December 20, 2011 (address: No. 3, No. 1, Beichen West Road, Chaoyang District, Beijing, Chinese Academy of Sciences Institute of Microbiology), the deposit number is CGMCC No.5614. the

A microbial agent, the active ingredient of which is Bacillus atrophaeus HMB22922 cells and its extracellular metabolites. the

The above-mentioned microbial bacterial agent can be a liquid preparation. the

The preparation method of the above-mentioned microbial bacterial agent comprises the following steps: strain activation, seed liquid preparation and fermentation culture. the

The preparation method of above-mentioned microbial bacterial agent specifically comprises the following steps:

(1) Strain activation: activate the HMB22922 strain preserved at low temperature on LB plate medium, pick a single colony and culture it on LB slant medium at 30°C for 24-36 hours to obtain the activated strain;

(2) Seed solution preparation: use a sterile inoculation loop to scrape a ring and inoculate the activated bacterial strain in step (1) into 100mL LB liquid medium, and cultivate it at 26～34°C and the shaker speed at 170～210rpm for 22～ 25 hours, get the seed solution;

(3) Fermentation culture: according to the ratio of 0.5% to 3.0% by volume, the seed solution of step (2) is inserted into the sucrose bean cake powder medium (pH value is 5.8 to 6.2), at a temperature of 28 to 34°C 1. Fermentation and cultivation under the condition of 170-210rpm for 36-54h to obtain fermentation broth; the composition and weight percentages of the sucrose bean cake powder medium are as follows: 2.0-3.0% sucrose, 1.6-2.4% bean cake powder %, NaCl 0.1-0.2%, CaCO ₃ 0.1-0.3%, KH ₂ PO ₄ 0.01-0.03%, MgSO ₄ 7H ₂ O 0.01-0.03%, and the rest is water;

(4) Detect the number of bacteria and spores in the fermentation broth, and stop the fermentation when the mature spores in the fermentation broth account for 90% of the total number of spores and bacteria; the obtained liquid preparation is the HMB22922 bacterial strain. the

The temperature described in steps (2) and (3) of the above preparation method is preferably 30-32° C.; the rotation speed of the shaker is preferably 210 rpm; and the incubation time is preferably 48 hours. the

The LB plate medium, LB slant medium and LB liquid medium are prepared according to conventional methods. the

The preparation method of the sucrose bean cake medium comprises mixing sucrose, bean cake powder, NaCl, CaCO ₃ , KH ₂ PO ₄ and MgSO ₄ ·7H ₂ O according to weight percentage, adding water, and stirring evenly.

In the above microbial agent, the number of viable bacteria of Bacillus atrophaeus HMB22922 is greater than 8.37×10 ⁸ cfu/mL.

The application of the bacillus atrophaeus HMB22922 in the prevention and treatment of cotton boll blight. the

The application of the above-mentioned microbial bacterial agent in the prevention and treatment of cotton boll blight. the

The method of using the microbial agent of the present invention: dilute the microbial agent obtained above with water until the number of viable bacteria is 10 ⁷ cfu/mL, and spray the surface of the cotton boll and the middle and lower leaves before the onset of the cotton boll blight, so as to achieve the purpose of controlling the cotton boll blight .

Screening and isolation process of HMB22922 strain

The HMB22922 strain was isolated from the cornfield soil in Xinji City, Hebei Province by the Institute of Plant Protection, Hebei Academy of Agriculture and Forestry Sciences. In 2010, the Institute of Plant Protection, Hebei Academy of Agriculture and Forestry Sciences collected rhizosphere soil from five points in the corn field of Xinji City, Hebei Province. After mixing, weigh 5g and put it into a 250mL sterile triangular flask, add 100mL sterile water, and put it on a shaker , shake at 170r/min for 30min, let stand for 2h, take 1mL of supernatant and add 9mL of sterile water to make 10mL10 ^-2 times soil microbial suspension, and then dilute the soil suspension to 10 ^-3 , 10 ^-4 , 10 ^{- 5.} For 10 ^-6 times dilutions, 200 μL of microbial suspension for each concentration was applied to LB and KB medium plates, each concentration was repeated 3 times, and incubated at 28°C for 1d-3d to isolate and purify the bacteria. And with cotton boll blight as the target, the screening of biocontrol bacteria was carried out by plate confrontation and artificial inoculation of isolated green bolls. Results A bacterial strain with obvious control effect on the target disease was screened out and named as HMB22922.

Classification and identification of HMB22922 strain:

(1) Identification of morphological characteristics

Cultured on LB medium, the bacterium was rod-shaped, and spores were produced after 10 hours of culture. The spores were middle-grown, oval, and the cysts were not enlarged. The acid-fast staining was negative, and there was no paraspore crystal. On the nutrient agar plate, at the early stage of culture, the colonies are light milky white, pus-like, round, with neat edges, and the colonies are raised in the shape of steamed buns, with a moist surface; at the later stage of culture, the colonies are light yellow, with irregular edges, and the surface is dry and wrinkled; on the nutrient agar slant Straight line culture, in a straight line; static culture in liquid medium, the surface of the white bacterial film. It is basically consistent with the morphological characteristics of Bacillus described in the "Common Bacteria System Identification Manual" (edited by Dong Xiuzhu, Science Press, 2001), and it is preliminarily judged that the bacterial strain HMB22922 belongs to Bacillus (Bacillus). the

(2) Identification and classification by 16S rDNA sequence

Using the genomic DNA of HMB22922 as a template and using F27 and R1492 as primers to perform PCR amplification on 16S rDNA, the primer sequences are:

F27: 5'AGAGTTTGATCATGGCTCAG3'; (SEQ ID No: 2),

R1492: 5'GGCTACCTTGTTACGACTT3'; (SEQ ID No: 3);

16S rDNA amplification reaction system is 50 μL: 10×PCR Buffer (Mg ²⁺ ) 5 μL; dNTPMixture (2.5mM) 5 μL; Taq (5U/μL) 1 μL, F27 (10 μmol/L) 1 μL, R1492 (10 μmol/L) 1 μL; HMB22922 genomic DNA 50ng; ddH ₂ O to make up to 50 μL. The reaction conditions of PCR were 95°C for 5min; 30 cycles of 95°C for 30s, 55°C for 30s, 72°C for 1.5min, and 72°C for 10min. The obtained PCR amplification product was subjected to gel electrophoresis and sent to Shanghai Sangon Bioengineering Co., Ltd. for sequencing to obtain the 16S rDNA sequence of HMB22922 (see SEQ ID No: 1). The 16S rDNA sequence of gained HMB22922 is carried out homology comparison in Genbank, and the 16S rDNA homology of bacterial strain HMB22922 and Bacillus reaches 99% (see Fig. 3); Construction phylogenetic tree (see Fig. 2), HMB22922 and Bacillus Bacillus atrophaeus aggregated together, indicating that HMB22922 is B.atrophaeus.

(3) Using physiological and biochemical characteristics to identify and classify

The Biolog microbial automatic identification system can be used to test the utilization of 95 carbon sources by strain HMB22922 so as to further determine its species characteristics and improve the reliability of strain identification. Put the purely cultured colony of the strain to be tested into sterile water, vibrate with an oscillator to make a cell suspension, then inoculate it on a 96-well GNIII identification plate with a multi-channel pipette gun, and then use Biolog Microstation software to read the data. Determine carbon source utilization. By comparing with the BIOLOG system database MicroLog software (Release Version 4.20.04), the classification of the strains to be tested can be known. The HMB22922 strain was sent to China Agricultural University, and the Biolog microbial automatic identification system was used for identification and classification. The identification results showed that HMB22922 belonged to B. atrophaeus. the

Based on the above morphological characteristics, comparative analysis of 16S rDNA sequence homology, and identification of physiological and biochemical characteristics, it can be known that HMB22922 belongs to Bacillus atrophaeus, and is different from the existing Bacillus atrophaeus strains, and is a new Bacillus atrophaeus strain. the

The present invention has advantages and beneficial effects: (1) the present invention provides an effective biological control approach for preventing and treating cotton boll blight; (2) the present invention has a good control effect on cotton boll blight, with an average control effect of more than 80%, and Strong pertinence; (3) the microbial agent of the present invention is safe for humans and animals and has no environmental pollution; (4) it is not easy to produce drug resistance by using the present invention to prevent and treat cotton boll blight; (5) the preparation method of the microbial agent of the present invention is simple and low in cost , Easy to use. the

Description of drawings

Figure 1 is a graph showing the antagonism of Bacillus atrophaeus HMB22922 to Phytophthora cotton boll, wherein A is Bacillus atrophaeus HMB22922, and B is Phytophthora cotton boll. the

Fig. 2 is a phylogenetic tree diagram obtained based on the 16S rDNA sequence of the HMB22922 strain. the

Fig. 3. is the 16S rDNA gene sequence homology map of HMB22922 bacterial strain of the present invention and Bacillus atrophaeus 1942 bacterial strain (B.atrophaeus 1942); Wherein "-" in the sequence of Bacillus atrophaeus 1942 bacterial strain represents that the corresponding base is identical with HMB22922 , "g, a, c, t" indicates that the bases corresponding to HMB22922 in the sequence of Bacillus atrophaeus 1942 strain are g, a, c, t; "·" indicates the base deletion of the corresponding site. the

Detailed ways

Example 1

The preparation of HMB22922 microbial bacterial agent is carried out according to the following steps:

(1) Strain activation: The bacterial strain HMB22922 (Bacillus atrophaeus) strain HMB22922 stored at -40°C has been preserved in the General Microorganism Center of the China Committee for the Collection of Microbial Cultures on December 20, 2011, and the preservation number is CGMCC No.5614) is activated (30°C) on LB plate medium (its composition and weight ratio are: tryptone 1g yeast extract 0.5g, sodium chloride 1g, agar powder 15g, water 1000mL), pick Take a single colony on LB slant medium (its composition and weight ratio are: tryptone 1g, yeast extract 0.5g, sodium chloride 1g, agar powder 15g, water 1000mL), culture at 30°C for 24-36 hours; the activated strain was obtained;

(2) Preparation of seed liquid: make LB liquid medium according to the conventional method (its composition and weight ratio are: tryptone 1g, yeast extract 0.5g, sodium chloride 1g, water 1000mL), in a 250mL Erlenmeyer flask Fill 100mL of LB liquid medium, and sterilize with high-pressure damp heat. After the temperature drops to room temperature, insert the strain activated by an inoculation loop in step (1) into each bottle, and carry out shaking culture on a shaker with a rotation speed of 190rpm and 30°C. Under culture for 24h, the gained is seed solution;

(3) Preparation of sucrose bean cake medium: add 3.0% sucrose, 2% bean cake powder, 0.1% NaCl, 0.3% CaCO _{3 ,} 0.02% KH ₂ PO ₄ and 0.03% MgSO ₄ 7H ₂ O to water according to weight percentage , Stir and mix evenly to obtain the sucrose bean cake medium; divide into 500mL Erlenmeyer flasks, 200mL per bottle; sterilize the sucrose bean cake medium at 121°C for 30 minutes, then cool down to 30°C for later use;

(4) Fermentation culture: inoculate 2 mL of the seed solution obtained in step (2) into 200 mL of the sucrose bean cake medium obtained in step (3); carry out fermentation and cultivation at 30 ° C and a shaker speed of 190 rpm for 36 hours, and then every 30 minutes Sampling from the triangular flask for microscopic examination, counting the number of spores and total thalline in the visual field, and calculating the spore rate (spore rate (%)=number of mature spores/(number of mature spores+number of thalline)×100); When the spore rate reaches 90%, the fermentation culture can be stopped; the co-fermentation culture is about 45-50 hours, and the liquid preparation of Bacillus atrophaeus HMB22922 is obtained. the

Example 2 Antagonism test of Bacillus atrophaeus HMB22922 to Phytophthora cotton boll

(1) Test time and place: In early August 2010, it was carried out in the Plant Disease Biological Control Laboratory of the Institute of Plant Protection, Hebei Academy of Agriculture and Forestry Sciences. the

(2) Test method:

(1) Source of cotton boll Phytophthora bacterium: Phytophthora 5-1 was collected from cotton bolls in Hejie Village, Hejie Town, Xianxian County, Cangzhou City, Hebei Province, and was isolated and purified by the Institute of Plant Protection, Hebei Academy of Agriculture and Forestry Sciences, Hebei Agricultural University The Plant Pathology Department of the School of Plant Protection identified it as Phytophthora boehmeriae, and the pathogenicity test showed strong pathogenicity. the

(2) Tablet confrontation experiment:

打孔制成菌片，将棉铃疫病菌菌片转接在另一个PDA平板中央，再将活化后的萎缩芽孢杆菌HMB22922点接在距指示菌菌片2.0厘米处，设空白对照(不点接HMB22922菌株的棉铃疫病菌生长情况)。25℃恒温培养，待空白对照即将长满整个培养皿时，测量棉铃疫病菌的对照生长量(菌落半径)和处理生长量(接种HMB22922后的抑制生长半径)，用拮抗作用抑菌率(抑菌率(％)＝(对照生长量-处理生长量)/对照生长量×100)表示。  First, Phytophthora 5-1 is activated on the PDA plate, and after 5 days of cultivation, in the edge area of the colony, use a puncher to

Punch holes to make bacterial slices, transfer the bacterial flakes of Phytophthora cotton bolligera to the center of another PDA plate, and then spot-connect the activated Bacillus atrophaeus HMB22922 at a distance of 2.0 cm from the bacterial flakes of the indicator bacteria. The growth of Phytophthora armigera of HMB22922 strain). Cultivate at a constant temperature of 25°C. When the blank control is about to cover the entire petri dish, measure the control growth amount (colony radius) and treatment growth amount (inhibition growth radius after inoculation of HMB22922) of Phytophthora cotton bolls, and use the antagonistic antibacterial rate (inhibition rate) Bacterial rate (%)=(control growth amount-treatment growth amount)/control growth amount×100).

(3) Results (Table 1) The inhibitory rate of Bacillus atrophaeus HMB22922 to Phytophthora solani was 85.71%; the transparent band of inhibition was 10.0 mm (see Figure 1). It shows that Bacillus atrophaeus HMB22922 has obvious inhibitory effect on cotton boll blight, and has biocontrol potential to control cotton boll blight. the

Table 1 The results of the antagonistic test of Bacillus atrophaeus HMB22922 against Phytophthora cotton boll

strain name Control growth (mm) Treatment growth (mm) Bacteriostatic rate (%) HMB22922 35.0 5.0 85.71

Example 3 Comparative test of Bacillus atrophaeus HMB22922 on the control of cotton boll blight

(1) Test drug:

(1) Microbial agent: the HMB22922 liquid preparation prepared in Example 1 was diluted 50 times with water. the

(2) Chemical agent: aluminum triethylphosphonate wettable powder (80%) (Zhejiang Jiahua Chemical Co., Ltd.), diluted 800 times with water. the

(3) Blank control: clear water. the

(2) The time and place of the experiment: in late August 2010, it was carried out in the artificial climate chamber of the Institute of Plant Protection, Hebei Academy of Agriculture and Forestry Sciences. the

(3) Test method: collect healthy bolls from the middle and upper parts of cotton plants in the test field (about 30 days after boll formation), require fresh bract leaves, and disinfect the surface with 75% alcohol after bringing them back to the laboratory, and let them dry naturally. Spray respectively on the surface of cotton bolls: (1) 50-fold dilution of the HMB22922 liquid preparation prepared in Example 1; (2) 800-fold dilution of the chemical agent triethylphosphonate aluminum wettable powder (80%); (3) blank control Clear water; After 24 hours, three pinholes were acupunctured with a sterile needle on the upper surface of the cotton boll, and the bacterium plate of Phytophthora cotton bolls was pasted (the Phytophthora cotton bolls inoculated on the PDA plate culture medium to obtain), with The bacterial plate (diameter 6mm) of Phytophthora spp. completely covers the pinhole shall prevail. Repeated 4 times, each repeated treatment was 10 cotton bolls. 25 ℃ constant temperature and moisture culture for 5-7 days. Investigate the incidence of the disease when the clear water spray treatment is sufficient, and calculate the disease index (disease index = 100 × ∑ (disease level × number of sick bells at this level)/(highest level value × total number of bells)) and control effect (control Effect (%)=(control condition index-treatment condition index)/control condition index×100) (the same below). The disease classification of cotton boll blight is divided into 5 grades according to the percentage of the diseased area to the boll surface area. The specific grading standards (the same below): 0, the cotton bolls are healthy and disease-free; Grade 2, the infected area of cotton bolls accounts for 1/4 to 1/2 of the entire surface area of cotton bolls; Grade 3, the infected area of cotton bolls occupies between 1/2 and 3/4 of the entire surface area of cotton bolls; Grade 4, the infected area of cotton bolls accounts for the entire surface area of cotton bolls More than 3/4 of the surface area of cotton bolls. the

(4) Results (see Table 2) The disease index of cotton boll blight treated with HMB22922 liquid preparation (19.87) was significantly lower than that of the blank control (60.00), but not significantly different from the disease index (24.88) of the chemical agent treatment. The control effect of the HMB22922 liquid preparation on the cotton boll blight is 66.88%, which shows that the Bacillus atrophaeus HMB22922 and its microbial agent of the present invention have a good control effect on the cotton boll blight. the

Table 2 The comparative test results of HMB22922 on the control of cotton boll blight

deal with Disease index Prevention effect (%) HMB22922 liquid preparation 19.87bc 66.88 Chemicals 24.88b 58.54 blank control 60.00a 0.00

Example 4 Comparative test of the control effect of Bacillus atrophaeus HMB22922 on cotton boll blight

(1) Test drug:

(1) Microbial agent: the HMB22922 liquid preparation prepared in Example 1 was diluted 50 times with water. the

(2) Chemical agent: aluminum triethylphosphonate wettable powder (80%) (Zhejiang Jiahua Chemical Co., Ltd.), diluted 800 times with water and sprayed. the

(3) Blank control: clear water. the

(2) The time and place of the experiment: In the first ten days of September 2010, it was carried out in the artificial climate chamber of the Institute of Plant Protection, Hebei Academy of Agriculture and Forestry Sciences. the

(3) Test method: collect healthy bolls from the middle and upper parts of cotton plants in the test field (about 30 days after boll formation), require fresh bract leaves, and disinfect the surface with 75% alcohol after bringing them back to the laboratory, and let them dry naturally. Three pinholes are needle-punched with a sterile needle on the surface of the upper part of the cotton boll, and the surface of the cotton boll is sprayed respectively: (1) 50 times dilution of the HMB22922 liquid preparation prepared in Example 1; (2) the wettability of the chemical agent triethylphosphonate aluminum Powder (80%) 800 times of spraying, (3) blank control is clear water spraying; After 24 hours, attach the Phytophthora cotton bolls bacterium tray (the Phytophthora cotton bolls inoculation in the embodiment 2 is propagated on the PDA plate culture medium and obtains) , take the cotton boll blight bacteria plate (diameter 6mm) to completely cover the pinhole as the criterion. Repeat 4 times, each treatment is 10 bolls. 25 ℃ constant temperature and moisture culture for 5-7 days. When the blank control was fully treated, the incidence was investigated, and the disease index and control effect were calculated. the

(4) Results (see Table 3): The disease index of cotton boll blight after treatment with HMB22922 liquid preparation (8.75) was significantly lower than the disease index (46.88) after the blank control treatment, and also significantly lower than the disease index (14.65) after the chemical agent treatment , but there is no significant difference between the disease finger and the chemical agent treatment; the control effect of HMB22922 on cotton boll blight is 81.34%, which is higher than that of chemical agent treatment, indicating that HMB22922 and its microbial agent of the present invention have a good control effect on cotton boll blight. the

Table 3 The comparative test results of HMB22922 on the control of cotton boll blight

deal with Disease index Prevention effect (%) HMB22922 liquid preparation 8.75c 81.34 Chemicals 14.65b 68.75 blank control 46.88a /

Example 5 Comparative Test of Bacillus atrophaeus HMB22922 on the Control Effect of Cotton Boll Blight

(1) Test drug:

(1) Microbial agent: the HMB22922 liquid preparation prepared in Example 1 was diluted 50 times with water. the

(2) Chemical agent: 80% aluminum triethylphosphonate wettable powder (Zhejiang Jiahua Chemical Co., Ltd.), diluted 800 times with water. the

(3) Blank control: clear water. the

(2) The time and place of the experiment: in late September 2010, it was carried out in the artificial climate chamber of the Institute of Plant Protection, Hebei Academy of Agriculture and Forestry Sciences. the

(3) Test method: collect healthy bolls from the middle and upper parts of cotton plants in the test field (about 30 days after boll formation), require fresh bract leaves, and disinfect the surface with 75% alcohol after bringing them back to the laboratory, and let them dry naturally. Spray on the upper surface of cotton bolls: (1) 50 times of dilutions of the HMB22922 liquid preparation prepared in Example 1, (2) the chemical agent contrast is aluminum triethylphosphonate wettable powder (80%) 800 times of dilutions spray, ( 3) The blank control is sprayed with clear water; after 24 hours, the bacterial plate of Phytophthora cotton bolls (obtained by inoculating the Phytophthora cotton bolls in Example 2 on a PDA plate culture medium) was pasted. Repeat 4 times, each treatment sample is 10 bolls. 25 ℃ constant temperature and moisture culture for 5-7 days. When the blank control was fully treated, the incidence was investigated, and the disease index and control effect were calculated. the

(4) Results (see Table 4): the cotton boll blight disease index (2.70) treated by the HMB22922 liquid preparation was significantly lower than the disease index (42.06) and the chemical agent treatment disease index (11.17) of the blank control treatment; the effect of HMB22922 on cotton boll blight The control effect reached 93.58%, which indicated that Bacillus atrophaeus HMB22922 and its microbial agent had a good control effect on cotton boll blight. the

Table 4 The comparative test results of HMB22922 on the control of cotton boll blight

deal with Disease index Prevention effect (%) HMB22922 liquid preparation 2.70c 93.58 Chemicals 11.17b 73.45 blank control 42.06a 0.00

Claims (2)

1. A Bacillus atrophaeus (Baci11us atrophaeus) strain HMB22922 was deposited in the General Microbiology Center of the China Committee for the Collection of Microbial Cultures on December 20, 2011, and the preservation number is CGMCC No. 5614. 2. the application of the bacillus atrophaeus (Baci11us atrophaeus) bacterial strain HMB22922 described in claim 1 in the prevention and treatment of cotton boll blight.

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