Application of azotobacter 18wly and its bacterial agent and fermentation liquor in prevention and treatment of wheat scab

Abstract

The present application relates to the technical field of biological pesticides, in particular to Paenibacillus sp. 18WLY, a bacterial agent containing the same and a fermentation liquor, and application of the Paenibacillus sp. 18WLY, the bacterial agent containing the same and the fermentation liquor in the prevention and treatment of wheat scab. The present application provides application of Paenibacillus sp. 18WLY, a bacterial agent containing the same and a fermentation liquor in the prevention and treatment of wheat scab. The bacteria can effectively prevent and treat wheat scab, and can be used as a green pesticide to reduce the use of chemical pesticides and improve the ecological environment.

Description

Technical Field

[0001] This invention relates to the field of biopesticide technology, specifically to the application of nitrogen-fixing Bacillus 18WLY and its inoculants and fermentation broth in the control of wheat scab. Background Technology

[0002] Frequent outbreaks of pests and diseases in the cultivation of vegetables, field crops, and fruit trees cause significant losses to farmers. Consequently, chemical pesticides are widely used in these crops. However, excessive pesticide use increases pesticide residues in vegetables, fruits, and grains, seriously threatening human health and the ecological environment. Developing and utilizing novel antimicrobial substances and fully leveraging the preventative and therapeutic effects of biological pesticides are of great significance for improving food safety and promoting the development of green agriculture.

[0003] Fusarium head blight, also known as wheat scab, is a disease of wheat caused by various Fusarium fungi. It can occur from the seedling stage to the heading stage, causing seedling rot, stem base rot, stalk rot, and ear rot, with ear rot being the most damaging. Under high humidity, a pinkish mold layer is visible on the diseased parts. Affected wheat exhibits reduced dry weight, decreased germination rate, weakened germination vigor, low flour yield, poor flour quality, dull color, and reduced commercial value. Diseased wheat contains toxins such as emetogenic toxins and estrogen-like substances, which can cause acute poisoning in humans and animals. Diseased wheat grains contain toxins such as deoxynivalenol and zearalenone, which can also cause abortion in pregnant animals after poisoning. Therefore, it is necessary to find a new, green, and environmentally friendly method to effectively control this disease. Summary of the Invention

[0004] The purpose of this invention is to provide a new method for preventing and controlling wheat scab.

[0005] The following technical solutions are specifically provided:

[0006] Application of nitrogen-fixing Bacillus sp. 18WLY in the control of wheat scab.

[0007] Application of microbial agents containing nitrogen-fixing Bacillus sp. 18WLY in the control of wheat scab.

[0008] Application of fermentation broth of nitrogen-fixing Bacillus sp. 18WLY in the control of wheat scab.

[0009] The nitrogen-fixing Bacillus sp. 18WLY strain of this invention is a nitrogen-fixing bacterium. This strain is deposited at the China General Microbiological Culture Collection Center (CGMCC, address: Institute of Microbiology, Chinese Academy of Sciences, Datun Road, Chaoyang District, Beijing, 100101, China), with accession number CGMCCNO.7724, and is specifically disclosed in Chinese patent CN103451130B. Research has shown that this strain can also inhibit plant pathogenic fungi, thus proposing its application in the control of wheat scab.

[0010] The fermentation broth was prepared by fermenting nitrogen-fixing Bacillus sp. 18WLY in KL medium.

[0011] The KL culture medium has a pH of 7.5 and the following formula:

[0012]

[0013] The PBS buffer solution is formulated as follows: 12g potassium dihydrogen phosphate, 72g disodium hydrogen phosphate, 400g sodium chloride, 10g potassium chloride, and brought to a final volume of 1000 ml.

[0014] Fermentation conditions are 30±2℃, 180-220rpm, and fermentation time is 2.8-3.2 days.

[0015] The specific application method for preventing and controlling wheat scab is to spray the diluted fermentation liquid directly onto the wheat plants.

[0016] The spraying time is after the winter wheat turns green again.

[0017] Specifically, the spraying time is from the end of April to the beginning of May in the north and from the end of March to the beginning of April in the south.

[0018] The beneficial effects of this invention are as follows:

[0019] This invention discovers a new and effective method for controlling wheat scab. Specifically, the fermentation broth of nitrogen-fixing Bacillus sp. 18WLY is used as a biological pesticide to control wheat scab, thereby reducing the amount of chemical pesticides used and improving the ecological environment. Attached Figure Description

[0020] Figure 1 The results are from the experiment in Example 1 of this invention, where A is the comparison result of wheat disease in the field and B is the comparison result of wheat ear and grain disease. Detailed Implementation

[0021] The following examples are used to illustrate the present invention, but are not intended to limit the scope of the invention.

[0022] Unless otherwise specified, the experimental methods used in the following examples are conventional methods.

[0023] Unless otherwise specified, all materials and reagents used in the following examples are commercially available.

[0024] Example 1

[0025] Nitrogen-fixing Bacillus sp. 18WLY was cultured in KL medium at 30°C and 200 rpm for 3 days. The inoculum size was 1%.

[0026] The pH of KL medium is 7.5, and the formula is as follows:

[0027]

[0028]

[0029] The PBS buffer solution is formulated as follows: 12g potassium dihydrogen phosphate, 72g disodium hydrogen phosphate, 400g sodium chloride, 10g potassium chloride, and brought to a final volume of 1000 ml.

[0030] Conduct field experiments:

[0031] The experimental area was selected from regions where wheat scab disease had been severe in previous years.

[0032] Fermentation broth of nitrogen-fixing Bacillus diluted 10 times (concentration 10) was used separately. 10 CFU / ml) and water were sprayed onto wheat plants at the heading stage before the onset of disease, at a rate of 12 m². 2 200 ml of fermentation broth was applied. Ten days later, 45 ml of fermentation broth was applied again to each plot. Each treatment was replicated in three plots, each plot measuring 40 square meters, with 452 wheat plants planted in each plot. Normal agricultural practices were followed during the experiment. Disease incidence was assessed 28 days after the first application. Wheat yield was measured by sampling. Before wheat harvest, three points were randomly selected for each treatment, with each point representing a 1-square-meter quadrat. The thousand-grain weight and total wheat grain weight within each quadrat were recorded, and the wheat yield per acre was calculated from the quadrat yield.

[0033] Wheat Fusarium Disease Index Survey:

[0034] One hundred ears were randomly sampled from each treatment. The number of ears with the proportion of diseased grains on each ear was counted and classified as follows: Grade 0, number of ears with no diseased grains; Grade 1, number of ears with <25% diseased grains; Grade 2, number of ears with 25% to less than 50% diseased grains; Grade 3, number of ears with 50% to 75% diseased grains; Grade 4, number of ears with >75% diseased grains; Grade 5, number of ears with all grains diseased. The disease index and control efficacy were calculated using the following formulas:

[0035] Disease index = Σ(number of ears at each level × corresponding level) / 5 × total number of ears.

[0036] Prevention efficacy = (Control disease condition - Bacterial solution disease condition) / Control disease condition.

[0037] In the control group, the wheat disease index reached 92.3%, indicating a severe outbreak of Fusarium head blight in the field. However, after treatment with the fermentation broth of nitrogen-fixing Bacillus 18WLY, the disease index decreased to 32.5%, demonstrating that the bacterial solution treatment of this invention has a good control effect on naturally occurring wheat Fusarium head blight in the field, achieving a control efficacy of 64.8%. Field disease observation results are shown below. Figure 1 A in the middle.

[0038] After treatment with the bacterial solution, the thousand-grain weight and yield per mu of wheat increased by 21.3% and 24.1% respectively compared with the control group; while the wheat in the control group had shriveled or even no grains in the ears, and the whole ear was severely diseased, resulting in a sharp decrease in wheat yield (see...). Figure 1 (B in the middle).

[0039] Furthermore, no phytotoxicity symptoms were found in any of the treatment areas after the application of the bacterial solution, and the wheat grew normally, indicating that the bacterial solution is safe for wheat growth and demonstrating its potential as a biological pesticide.

[0040] Although the present invention has been described in detail above with general descriptions and specific embodiments, modifications or improvements can be made to it, which will be obvious to those skilled in the art. Therefore, all such modifications or improvements made without departing from the spirit of the present invention fall within the scope of protection claimed by the present invention.

Claims

1. Application of Paenibacillus sp. 18WLY in preventing and treating wheat scab; the Paenibacillus sp. 18WLY has a preservation number of CGMCC NO. 7724.

2. Application of a microbial agent containing Paenibacillus sp. 18WLY in preventing and treating wheat scab; the Paenibacillus sp. 18WLY has a preservation number of CGMCC NO. 7724.

3. Application of a fermentation liquor of Paenibacillus sp. 18WLY in preventing and treating wheat scab; the Paenibacillus sp. 18WLY has a preservation number of CGMCC NO. 7724.

4. Use according to claim 3, characterized in that, The fermentation liquor is prepared by fermenting Paenibacillus sp. 18WLY in KL medium.

5. Use according to claim 4, characterized in that, The KL medium has a pH of 7.5 and the following formula:

6. Use according to claim 5, characterized in that, The PBS buffer has the following formula: 12 g of potassium dihydrogen phosphate, 72 g of sodium hydrogen phosphate, 400 g of sodium chloride, 10 g of potassium chloride, and the volume is made up to 1000 ml.

7. Use according to any one of claims 4 to 6, characterized in that, The fermentation conditions are 30±2℃, 180-220 rpm, and the fermentation time is 2.8-3.2 days.

8. Use according to claim 3, characterized in that, The specific application mode for preventing and treating wheat scab is to directly spray the diluted fermentation liquor on the wheat plants.

9. Use according to claim 8, characterized in that, The spraying time is after the winter wheat turns green.

10. Use according to claim 9, characterized in that, The spraying time is at the end of April to the beginning of May in the north and at the end of March to the beginning of April in the south.

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