A biological agent for preventing and treating wheat scab and a preparation method and application thereof

Abstract

The application discloses a kind of biological inoculant for preventing and treating wheat scab and a preparation method and application thereof, belong to plant disease control technical field.The microbial inoculant is prepared from the following raw materials by weight percentage: Trichoderma harzianum 5-10 parts, Streptomyces microflavus 2-5 parts, Bacillus subtilis 2-5 parts, soybean meal 75-90 parts, vitamin B1 0.1-0.5 parts, potassium fulvate 2-5 parts and ferrous phosphate 2-5 parts.The microbial inoculant of the application uses Trichoderma harzianum, Streptomyces microflavus and Bacillus subtilis as biocontrol strains, which has inhibitory effect on Fusarium asiaticum.The wheat scab control scheme of the application is environmentally friendly and sustainable.The application enhances the resistance and biodiversity of crops, reduces the dependence on chemical pesticides and promotes the balance of agricultural ecology.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of plant disease control, and particularly relates to a biological fungicide for preventing and treating wheat scab and a preparation method and application thereof. BACKGROUND

[0002] The dominant population of the pathogen of wheat scab is fusarium asiaticum. The pathogen mainly invades in the flowering stage of wheat, and shows symptoms in the grain filling stage. When the wheat heading and flowering stage encounters warm and humid conditions, ascospores are released from the ascocarps, spread by air and rain, and land on the withered anthers of the floret to infect the spikelet. The climate in the northern region of Zhejiang is humid and rainy, especially the continuous rainy weather during the wheat heading and flowering stage, which is the most important environmental factor determining the occurrence of scab. Ear rot is the most common symptom of wheat scab. At the early stage of the disease, small water-stained light brown lesions appear on the spikelet and glume, and then gradually expand to the entire spikelet, causing the spikelet to turn yellow. When the humidity is high, a pink gelatinous mold layer appears on the lesion, and small black dots, i.e. ascocarps, appear on it in the later stage. The disease then spreads to the ear axis, causing the affected part to turn brown, and the small spikelets above the affected part to form withered ears. Seedling rot is caused by the infection of pathogenic bacteria from the seed or soil. The bud turns brown first, and then the root crown rots. Lightly infected seedlings are yellow and thin, while severely infected seedlings die. The disease can cause a 10%-20% reduction in wheat yield, and a severe reduction of 80%-90% in yield. In addition, after infection with scab, mycotoxins such as deoxynivalenol (DON) and zearalenone (ZEN) are produced in the wheat grains, which not only affects the processing quality and food safety of wheat, but also can cause poisoning events such as fever, vomiting and diarrhea in humans and animals after accidental ingestion.

[0003] At present, the prevention and treatment of wheat scab mainly relies on chemical fungicides. However, the prevention and treatment method using chemical fungicides has certain limitations. On the one hand, fusarium graminearum invades at different stages of wheat growth and development, and different chemical agents need to be used for prevention and treatment, resulting in high prevention and treatment cost. On the other hand, when it rains during the full bloom stage of wheat, the chemical agents are easily washed away by rain, which seriously weakens the prevention and treatment effect. In addition, long-term use of chemical pesticides can lead to the development of drug resistance in pathogenic bacteria, pollution of the environment, and destruction of the ecological balance. If microbial agents are used to prevent and treat wheat scab, the stability and prevention and treatment effect of microbial preparations are greatly affected by environmental factors. In practical application, the shelf life of microbial preparations is short, the storage and transportation conditions are harsh, and the sensitivity of pathogenic bacteria in different regions to microbial preparations may differ. Therefore, it is of great significance to provide a biological fungicide that can effectively prevent and treat wheat scab. SUMMARY

[0004] The present application aims to provide a biological microbial agent for preventing and treating wheat scab and a preparation method and application thereof, so as to solve the problems of the prior art. The microbial agent in the wheat scab prevention and treatment scheme of the present application is environmentally friendly and sustainable. The present application enhances the resistance and biodiversity of crops, reduces the dependence on chemical pesticides, and promotes the ecological balance of agriculture.

[0005] To achieve the above-mentioned purpose, the present application provides the following solutions.

[0006] Technical solution one: a microbial agent for preventing and treating wheat scab, which is prepared from raw materials including the following weight fractions: Trichoderma harzianum 5-10 parts, Streptomyces microflavus 2-5 parts, Bacillus subtilis 2-5 parts, soybean meal 75-90 parts, vitamin B1 0.1-0.5 parts, potassium fulvate 2-5 parts, and ferrous phosphate 2-5 parts.

[0007] Further, the microbial agent is prepared from raw materials including the following weight fractions: Trichoderma harzianum 7 parts, Streptomyces microflavus 4 parts, Bacillus subtilis 3 parts, soybean meal 80 parts, vitamin B1 0.3 parts, potassium fulvate 3 parts, and ferrous phosphate 3 parts.

[0008] Further, the bacterial content of the Trichoderma harzianum is 70-100 billion CFU / g; the bacterial content of the Streptomyces microflavus is 50-90 billion CFU / g; and the bacterial content of the Bacillus subtilis is 50-90 billion CFU / g.

[0009] Further, the bacterial content of the Trichoderma harzianum is 90 billion CFU / g; the bacterial content of the Streptomyces microflavus is 70 billion CFU / g; and the bacterial content of the Bacillus subtilis is 60 billion CFU / g.

[0010] Further, the microbial agent is applied during the wheat heading and flowering period.

[0011] Technical solution two: a preparation method of the microbial agent, which comprises uniformly mixing the Trichoderma harzianum, the Streptomyces microflavus, and the Bacillus subtilis with the soybean meal, and then adding the vitamin B1, the potassium fulvate, and the ferrous phosphate, and uniformly mixing to obtain the microbial agent.

[0012] Technical solution three: application of the microbial agent in preventing and treating wheat scab.

[0013] Technical solution four: application of the microbial agent in preparing a biocontrol drug for preventing and treating wheat scab.

[0014] Technical solution five: a biocontrol drug for preventing and treating wheat scab, comprising the microbial agent.

[0015] Technical solution six: A method for preventing and treating wheat scab, comprising the step of applying the microbial agent during the wheat heading and flowering period.

[0016] The following technical effects are disclosed in the present application:

[0017] The present application provides a microbial agent for preventing and treating wheat scab, which is composed of Trichoderma harzianum, Streptomyces microflavus and Bacillus subtilis. The three microorganisms have different mechanisms of action. Trichoderma harzianum can parasitize or produce antibacterial substances to inhibit pathogenic bacteria. Streptomyces microflavus can produce abundant secondary metabolites. Bacillus subtilis can produce active substances. They cooperate with each other to more comprehensively inhibit the growth, reproduction and infection of wheat scab pathogen, and improve the prevention and treatment effect. Specifically, Trichoderma harzianum can promote the growth of wheat seedlings and improve the disease resistance of wheat. Bacillus subtilis can promote the absorption of nutrients in the soil for wheat. Streptomyces microflavus can secrete plant hormones such as auxin and cytokinin during the metabolism process. Auxin can promote cell elongation and division, increase the volume and number of root system cells, and thus promote the growth and elongation of root system. Cytokinin can stimulate cell division, increase the activity of root meristem, promote the formation of new roots and the branching of root system, and make the root system more developed. Soybean meal is a byproduct obtained after soybean oil is extracted from soybeans, which contains rich nutritional ingredients such as protein, fat and minerals. It can provide nutrition, and also can be used as a carrier and adsorbent for microorganisms. Potassium fulvate can improve soil structure, increase soil fertility, promote plant growth, and also can provide a suitable living environment for microorganisms, and enhance the effect of microbial agent. Ferrous phosphate can be added to fertilizer or soil conditioner as a nutritional supplement to provide iron elements for the growth of wheat, enhance the stress resistance of wheat, and indirectly improve its resistance to scab. Vitamin B1 can provide additional nutrition and stimulation for wheat, improve its stress resistance and immunity, and enhance the inhibitory effect on the pathogen of scab.

[0018] Compared with chemical pesticides, the microbial agent provided by the present application is more environmentally friendly, does not cause pesticide residues and environmental pollution, can reduce the use amount of chemical pesticides, reduce production cost, and also helps to maintain the balance of farmland ecosystem and biodiversity. The wheat scab prevention and treatment scheme of the present application is environmentally friendly and sustainable. The present application enhances the resistance and biodiversity of crops, reduces the dependence on chemical pesticides, and promotes the balance of agricultural ecology. It can also be used as an eco-friendly alternative to reduce the use of traditional chemical pesticides, thereby reducing its impact on the environment and ecosystem, and has a wide prospect in the field of agricultural production. DETAILED DESCRIPTION

[0019] The following detailed description of various example embodiments of the application will not be considered limiting of the application, but rather a description of certain aspects, features and embodiments of the application.

[0020] It is to be understood that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. Additionally, for a range of values of a parameter, unless otherwise indicated, each intervening value by each intervening value, as well as any other stated or intervening value in that stated range is encompassed. The upper and lower limits of these intervening values can independently be included or excluded in the range, and each smaller range that "falls" within the ambit of the larger range is also encompassed. These smaller ranges can be independently combined with any other smaller range or point to fall within the ambit of the larger range.

[0021] Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. Although preferred methods and materials are described herein, any methods and materials similar or equivalent to those described herein can be used in the practice or testing of the present application. All documents mentioned herein are incorporated by reference to disclose and describe the methods and / or materials in connection with which the documents are cited. In case of conflict, the content of the present specification will control.

[0022] Various modifications and changes can be made to the specific embodiments of the application described herein without departing from the scope or spirit of the application. Other embodiments of the application will be apparent to those of ordinary skill in the art from the description and examples presented herein. The description and examples are illustrative of the application and are not intended to limit the scope of the application.

[0023] As used herein, the terms "comprises", "comprising", "includes", "including", "has", "having", "contains", "containing", or variations thereof, are intended to be open-ended terms that mean including, but not limited to.

[0024] The strains involved in the present embodiment are as follows: Trichoderma harzianum CICC41290 is purchased from China Industrial Microbial Culture Collection Center; Streptomyces microflavus is purchased from Shandong Hezhong Kangyuan Biological Technology Co., Ltd.; Bacillus subtilis is purchased from Shanghai Gaoming Chemical Co., Ltd. Other reagents and materials not specifically mentioned can be obtained by conventional purchase by those skilled in the art.

[0025] Example 1

[0026] A microbial agent for preventing and treating wheat scab, the specific preparation process is as follows:

[0027] Preparation: Ensure the operating environment is clean and sterile, and prepare the required instruments and containers, measure and prepare each ingredient according to the required amount;

[0028] Preparation process: according to the weight fraction, 7 parts of Trichoderma harzianum, 4 parts of Streptomyces microflavus and 3 parts of Bacillus subtilis are mixed with 80 parts of soybean meal, 0.3 parts of vitamin B1, 3 parts of potassium fulvate and 3 parts of ferrous phosphate are added and mixed again, and the microbial inoculant is obtained after mixing. Among them, the bacterial content of Trichoderma harzianum is 9 billion CFU / g; the bacterial content of Streptomyces microflavus is 7 billion CFU / g; the bacterial content of Bacillus subtilis is 6 billion CFU / g.

[0029] Storage: Avoid exposing the microbial inoculant to direct sunlight or extreme temperature conditions, store in a dry and cool place, and avoid contact with other chemicals.

[0030] Example 2

[0031] A kind of microbial inoculant for preventing and treating wheat scab, the specific preparation process is as follows:

[0032] Preparation: Ensure the operating environment is clean and sterile, and prepare the required instruments and containers, measure and prepare each ingredient according to the required amount;

[0033] Preparation process: according to the weight fraction, 5 parts of Trichoderma harzianum, 2 parts of Streptomyces microflavus and 2 parts of Bacillus subtilis are mixed with 75 parts of soybean meal, 0.1 parts of vitamin B1, 2 parts of potassium fulvate and 2 parts of ferrous phosphate are added and mixed again, and the microbial inoculant is obtained after mixing. Among them, the bacterial content of Trichoderma harzianum is 7 billion CFU / g; the bacterial content of Streptomyces microflavus is 5 billion CFU / g; the bacterial content of Bacillus subtilis is 5 billion CFU / g.

[0034] Storage: Avoid exposing the microbial inoculant to direct sunlight or extreme temperature conditions, store in a dry and cool place, and avoid contact with other chemicals.

[0035] Example 3

[0036] A kind of microbial inoculant for preventing and treating wheat scab, the specific preparation process is as follows:

[0037] Preparation: Ensure the operating environment is clean and sterile, and prepare the required instruments and containers, measure and prepare each ingredient according to the required amount;

[0038] Preparation process: 10 parts of Trichoderma harzianum, 5 parts of Streptomyces microflavus and 5 parts of Bacillus subtilis, and 90 parts of soybean meal were mixed, 0.5 parts of vitamin B1, 5 parts of potassium fulvate and 5 parts of ferrous phosphate were added and mixed again, and then the microbial inoculant was obtained after mixing. Among them, the bacterial content of Trichoderma harzianum is 100 billion CFU / g; the bacterial content of Streptomyces microflavus is 90 billion CFU / g; the bacterial content of Bacillus subtilis is 90 billion CFU / g.

[0039] Storage: Avoid exposing the microbial inoculant to direct sunlight or extreme temperature conditions, store in a dry and cool place, and avoid contact with other chemicals.

[0040] Comparative Example 1

[0041] The difference between this comparative example and Example 1 is only that Bacillus subtilis is omitted, and the other operations are the same as those in Example 1.

[0042] Comparative Example 2

[0043] The difference between this comparative example and Example 1 is only that Streptomyces microflavus is omitted, and the other operations are the same as those in Example 1.

[0044] Comparative Example 3

[0045] The difference between this comparative example and Example 1 is only that Trichoderma harzianum is omitted, and the other operations are the same as those in Example 1.

[0046] Comparative Example 4

[0047] The difference between this comparative example and Example 1 is only that potassium fulvate is omitted, and the other operations are the same as those in Example 1.

[0048] Comparative Example 5

[0049] The difference between this comparative example and Example 1 is only that ferrous phosphate is omitted, and the other operations are the same as those in Example 1.

[0050] Comparative Example 6

[0051] The difference between this comparative example and Example 1 is only that the preparation process of this comparative example: 11 parts of Trichoderma harzianum, 6 parts of Streptomyces microflavus and 6 parts of Bacillus subtilis, and 70 parts of soybean meal were mixed, 0.6 parts of vitamin B1, 1 part of potassium fulvate and 6 parts of ferrous phosphate were added and mixed again, and then the microbial inoculant was obtained after mixing. The other operations are the same as those in Example 1.

[0052] Comparative Example 7

[0053] The difference between the present comparative example and Example 1 is only in the preparation process of the present comparative example: the Trichoderma harzianum has a bacterial content of 11 billion CFU / g; the Streptomyces microflavus has a bacterial content of 10 billion CFU / g; and the Bacillus subtilis has a bacterial content of 4 billion CFU / g. The other operations are the same as those in Example 1.

[0054] Test Example 1

[0055] This test example uses indoor potting experiments to detect the control effect of the microbial inoculants of each group (Examples 1-3 and Comparative Examples 1-7) on wheat scab and the colonization effect of the biocontrol bacteria (Trichoderma harzianum, Streptomyces microflavus and Bacillus subtilis). The specific process is as follows:

[0056] The test soil is sterilized at 121°C for 2h, then dried, inoculated with Fusarium asiaticum at a ratio of 1×10 5 CFU / g of dry soil. The test soil is moved into pots, and the humidity of the test soil is adjusted to 60%. The microbial inoculants of each group are applied to the pots at a dose of 1×10 5 CFU / g of dry soil (the same number of bacteria is applied in this test example to facilitate result analysis), the wheat seeds are disinfected, and then 10 seeds are sown per pot. In addition, a blank control group and a positive control group are set, the blank control group is neither inoculated with pathogenic bacteria nor inoculated with microbial inoculants, and the positive control group is only inoculated with pathogenic bacteria. Each group has 3 replicates. After 10 days of sowing at 20°C and soil moisture content of 19%, the wheat emergence rate is counted, as shown in Table 1.

[0057] At the same time, 5cm below the surface soil of the pots is taken on the 1st day, the 7th day and the 20th day after sowing, and the dilution plate counting method is used to count the number of Fusarium asiaticum and biocontrol bacteria in Examples 1, Comparative Example 3 and Comparative Example 6 with obvious effect, as shown in Table 2. The statistical results are the average values.

[0058] The wheat emergence rate statistical results are shown in Table 1.

[0059] Table 1 Wheat emergence rate of each group

[0060]

[0061]

[0062] Table 1 shows that scab can reduce the emergence rate of wheat, and the microbial inoculants of Examples 1-3 can inhibit the pathogenic bacteria and improve the emergence rate of wheat, reaching a state similar to that of the blank control group. When a certain raw material is omitted or the amount is adjusted, the inhibition of the microbial inoculants on the pathogenic bacteria decreases, and the improvement effect on the emergence rate of wheat decreases. When Trichoderma harzianum, Streptomyces microflavus and Bacillus subtilis are added together in the microbial inoculants, the improvement effect on the emergence rate of wheat is obvious.

[0063] The statistical number of F. asiatica and biocontrol bacteria in each group of soil is shown in Table 2.

[0064] Table 2 Statistical number of F. asiatica and biocontrol bacteria in each group of soil

[0065]

[0066] Table 2 shows that on the 1st day after inoculation / seed, both the pathogenic bacteria and the biocontrol bacteria show a downward trend, and on the 7th day and the 20th day, they show an upward trend, which indicates that the microorganism of the present application needs to gradually adapt to the complex soil environment. However, as can be seen from Example 1, Comparative Examples 3 and 6, only when the Trichoderma harzianum, Streptomyces microflavus and Bacillus subtilis are added into the microbial inoculant in a specific ratio, can the adaptability of the biocontrol bacteria be effectively improved, and the colonization rate be improved; the effect of single addition is obviously lower than that of the three together.

[0067] In summary, the microbial inoculant of the present application has an inhibitory effect on F. asiatica, and when the Trichoderma harzianum, Streptomyces microflavus and Bacillus subtilis are added into the microbial inoculant together, the improvement effect on the emergence rate of wheat is obvious.

[0068] The above-described examples only describe the preferred modes of the present application, and do not limit the scope of the present application, and various modifications and improvements to the technical solutions of the present application made by those skilled in the art without departing from the design spirit of the present application shall fall within the protection scope determined by the claims of the present application.

Claims

1. A microbial inoculant for controlling wheat scab, characterized in that, The microbial agent is prepared from the following raw materials in parts by weight: 5-10 parts of Trichoderma harzianum, 2-5 parts of Streptomyces flavus, 2-5 parts of Bacillus subtilis, 75-90 parts of soybean meal, 0.1-0.5 parts of vitamin B1, 2-5 parts of potassium humate, and 2-5 parts of ferrous phosphate. The bacterial count of *Trichoderma harzianum* is 7-10 billion CFU / g; the bacterial count of *Streptomyces flavus* is 5-9 billion CFU / g; and the bacterial count of *Bacillus subtilis* is 5-9 billion CFU / g.

2. The microbial agent according to claim 1, characterized in that, The microbial agent is prepared from the following raw materials in parts by weight: 7 parts Trichoderma harzianum, 4 parts Streptomyces flavus, 3 parts Bacillus subtilis, 80 parts soybean meal, 0.3 parts vitamin B1, 3 parts potassium humate, and 3 parts ferrous phosphate.

3. The microbial agent according to claim 1, characterized in that, The bacterial count of *Trichoderma harzianum* is 9 billion CFU / g; the bacterial count of *Streptomyces flavus* is 7 billion CFU / g; and the bacterial count of *Bacillus subtilis* is 6 billion CFU / g.

4. The microbial inoculant according to any one of claims 1-3, characterized in that, The microbial agent is applied during the wheat heading and flowering stage.

5. A method for preparing a microbial inoculant according to any one of claims 1-3, characterized in that, The process involves mixing the *Trichoderma harzianum*, the *Streptomyces flavus*, and the *Bacillus subtilis* with soybean meal, then adding vitamin B1, potassium humate, and ferrous phosphate, and mixing thoroughly to obtain the microbial inoculant.

6. The use of a microbial agent according to any one of claims 1-3 in the prevention and control of wheat scab.

7. The use of the microbial agent according to any one of claims 1-3 in the preparation of a biocontrol agent for the prevention and control of wheat scab.

8. A biocontrol agent for controlling wheat scab, characterized in that, It includes the microbial inoculant according to any one of claims 1-3.

9. A method for controlling wheat scab, characterized in that, The step includes applying the microbial agent according to any one of claims 1-3 during the wheat heading and flowering stage.

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