A microbial agent for preventing and treating root rot of golden olive and its application

Abstract

The present invention relates to a microbial agent for preventing and treating root rot of golden olive and its application. The microbial agent comprises the following components: Bacillus velezcema with a preservation number of CCTCC No: M2022923 ( Bacillus velezensis ), Bacillus subtilis with a deposit number of CCTCC No: M20221207 ( Bacillus subtle ), marigold extract, amino acids, humic acid and trace elements. The microbial agent can significantly improve the physical and chemical properties of the soil for the cultivation of golden olives, increase enzyme activity and microbial diversity, reduce the content of phenolic acid and Fusarium toxins in the soil, and thus reduce the Fusarium nightshade ) and oomycetes ( Pythium aphanidermatum ) and ultimately achieve the prevention and control of golden olive root rot.

Description

Technical Field

[0001] The invention belongs to the technical field of microorganisms and organic fertilizers, and in particular relates to a microbial agent for preventing and treating root rot of golden olive and an application thereof. Background Art

[0002] Golden olive TinosporaeRadix ) is a traditional Chinese medicinal material, first recorded in "Baicao Jing" in the Qing Dynasty. The tubers are in the shape of beads, and are also called Jiulianzi, Dikudan, etc. The dried tubers are used as medicine, which has the effects of clearing away heat and detoxifying, relieving sore throat, reducing swelling and relieving pain.

[0003] With the adjustment of agricultural production structure, the large-scale cultivation of golden olives, due to the lack of reasonable field management measures, such as improper fertilization methods and field water management, has led to the accumulation of harmful substances in the soil, deficiency of trace elements and disorder of soil microecology, which in turn has caused a large accumulation of pathogenic microorganisms in the soil, causing serious epidemic root rot diseases.

[0004] Golden fruit olive root rot is a disease caused by Fusarium spp. Fusarium solani ) and oomycetes ( Pythium aphanidermatum ) is a devastating disease caused by complex infection. The disease spreads quickly and is difficult to prevent and control. The mortality rate of infected plants is high. Once it occurs, it will cause great losses to farmers and the ecological environment. The cost of disease prevention and control is high, generally 10-20 times the cost of above-ground disease prevention and control, but the effect is minimal. The main reason for the difficulty in disease prevention and control is that disease prevention and control is a blind spot for chemical pesticides, that is, chemical pesticides alone are basically unable to control underground diseases. This is determined by the two completely different environmental conditions on the ground and underground. Whether it is antibiotics or other chemical fungicides, their foothold is to "kill", but for these stubborn pathogens, the killing effect is simply unattainable. This is because on the one hand, one of the consequences of indiscriminate use of chemical fungicides is the cultivation of stronger and stronger drug-resistant strains from generation to generation, and on the other hand, chemical pesticides are a double-edged sword, and there are strict restrictions on the concentration and interval of use, otherwise it will harm the crop itself. Also, most of these pathogens are inside the root system or microtubule bundles, which greatly increases the difficulty of killing. Therefore, the root rot of golden olive is one of the most difficult crop diseases to prevent and control in production. The pathogenic mechanism of this type of pathogen is not yet clear, and effective measures and technologies for preventing and controlling the disease have not been established in production. Summary of the invention

[0005] The purpose of the present invention is to provide a microbial agent and application for preventing and treating root rot of golden olives in view of the problems that chemical fertilizers and pesticides in the prior art have poor effects and high environmental risks in the process of planting golden olives. The microbial agent provided by the present invention can significantly improve the physical and chemical properties of the soil for planting golden olives, increase enzyme activity and microbial diversity, reduce the content of phenolic acid and Fusarium toxin in the soil, and thus reduce the Fusarium solani ) and oomycetes ( Pythium aphanidermatum ) has a good prevention and control effect on the root rot of golden fruit olive.

[0006] To achieve the above object, the present invention provides a microbial agent in the first aspect, comprising the following components: Bacillus Velezii ( Bacillus velezensis ), Bacillus subtilis with a deposit number of CCTCC No: M20221207 ( Bacillus subtilis ), marigold extract, amino acids, humic acid and nutrients.

[0007] Furthermore, the amount of Bacillus Velez in the bacterial agent is such that the content of Bacillus Velez in the bacterial agent is 1×10 8 -2×10 8 cfu / g; the amount of Bacillus subtilis in the bacterial agent is such that the content of Bacillus subtilis in the bacterial agent is 1×10 8 -2×10 8 cfu / g.

[0008] Furthermore, the weight ratio of the marigold extract, amino acid, humic acid and nutrient elements is 5-10:5-10:78-89:1-2. The nutrient elements include P2O 5、 K2O, calcium, magnesium, zinc and iron, wherein the weight ratio of P2O5, K2O, calcium, magnesium, zinc and iron is 36-55:20-30:15-20:6-8:2.5-3.5:1.5-2.5.

[0009] Furthermore, the total amount of the Bacillus Velez and Bacillus subtilis inoculants is 3%-5% of the total weight of the inoculants.

[0010] Further, the marigold extract has a water content of 10-20% by weight; based on dry matter, the lutein content is 40-60% by weight, the flavonoid content is 5-10% by weight, and the carotenoid content is 1-2% by weight. And / or, the humic acid has a water content of 5-10% by weight. And / or, the amino acid has a water content of 5-10% by weight.

[0011] The second aspect of the present invention provides the use of the above-mentioned microbial agent in improving the physical and chemical properties of crop-growing soil, and / or, increasing soil enzyme activity and microbial diversity, and / or, reducing the content of phenolic acid and Fusarium toxin in the soil, and / or, preventing and controlling crop root rot.

[0012] Furthermore, the crop root rot is selected from Fusarium oxyphylla ( Fusarium solani ) root rot and oomycetes ( Pythium aphanidermatum) root rot; wherein the pathogen causing the root rot of the golden fruit olive is Fusarium ( Fusarium solani ) and oomycetes ( Pythium aphanidermatum ).

[0013] The third aspect of the present invention provides a method for improving the physical and chemical properties of crop-growing soil, and / or increasing soil enzyme activity and microbial diversity, and / or reducing the content of phenolic acid and Fusarium toxin in the soil, and / or preventing and controlling crop root rot. The method comprises applying the above-mentioned bacterial agent to the rhizosphere soil of the crop, and the amount of the bacterial agent applied to the rhizosphere soil of the crop is 100-200g / plant / time, and the application frequency is 3 times during the entire growth period.

[0014] Through the above technical solution, the present invention can at least achieve the following beneficial effects:

[0015] (1) The microbial agent provided by the present invention can effectively improve the physical and chemical properties of the soil for growing golden olives, such as pH, alkaline nitrogen, available phosphorus, quick-acting potassium, exchangeable calcium and exchangeable magnesium, and effectively improve the activities of soil urease, sucrase, acid phosphatase, β-1,4-glucosidase and β-1,4-acetylglucosaminidase, and improve the diversity indexes of soil bacteria and fungi, such as ACE, Chao I, Simpson and Shannon, thereby improving the ability of plants to resist disease infection.

[0016] (2) Continuous cropping leads to the accumulation of phenolic acid substances in the soil, soil acidification, nutrient imbalance, a decrease in the abundance of beneficial microbial populations, and an increase in the abundance of pathogenic bacteria, which aggravates the occurrence of root rot. The microbial agent provided by the present invention significantly reduces the content of phenolic acid substances in the soil while improving the physical and chemical properties, enzyme activity and microbial diversity of the soil, thereby significantly reducing the disease index of the root rot of the golden fruit olive, thereby achieving effective prevention and control of the root rot of the golden fruit olive.

[0017] (3) Fusarium is an important pathogen that causes root rot of crops. The specialized type of the fungus produces toxins that play an important role in the pathogenic process. Especially after the pathogen invades the host, the toxins can cause pathological changes such as browning and necrosis of plant vascular cells, leading to crop yield reduction. Reducing the content of Fusarium toxins in the soil is an effective measure to control the occurrence of diseases. The bacterial agent provided by the present invention can significantly reduce the content of fumonisin B1, fumonisin B2 and fusaric acid in the soil of golden fruit olive planting, thereby achieving effective prevention and control of golden fruit olive root rot.

[0018] Biological Deposit

[0019] The Bacillus Velezii used in the present invention is classified and named Bacillus velezensisSH-1471 was deposited in the China Center for Type Culture Collection on June 20, 2022, at 299 Bayi Road, Wuchang District, Wuhan City, Hubei Province, Wuhan University, with a deposit number of CCTCC No: M2022923. The deposit information of the strain has been disclosed in the prior invention patent application number: CN202211479280.X.

[0020] The Bacillus subtilis used in the present invention is classified and named Bacillus subtilis SH-52 was deposited in the China Center for Type Culture Collection on August 1, 2022, at 299 Bayi Road, Wuchang District, Wuhan City, Hubei Province, Wuhan University, with a deposit number of CCTCC No: M20221207. The deposit information of the strain has been disclosed in the prior invention patent application number: CN202211479391.0. DETAILED DESCRIPTION

[0021] The endpoints and any values ​​of the ranges disclosed in this article are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of each range, the endpoint values ​​of each range and the individual point values, and the individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed in this article.

[0022] In the present invention, Bacillus Velez SH-1471 and Bacillus Velez CCTCC No: M2022923 are the same strain, and the two have the same meaning, and their names (numbers) can be used interchangeably. Bacillus subtilis SH-52 and Bacillus subtilis CCTCC No: M20221207 are the same strain, and the two have the same meaning, and their names (numbers) can be used interchangeably.

[0023] The inventors of the present invention isolated and obtained a strain of Bacillus Velezii ( Bacillus from Velez ), named SH-1471, was deposited in China Center for Type Culture Collection on June 20, 2022, with the deposit number CCTCC No: M2022923. And a strain of Bacillus subtilis ( Bacillus subtilis ), named SH-52, and deposited in the China Center for Type Culture Collection on August 1, 2022, with the deposit number CCTCC No: M 20221207. Studies have found that strains SH-1471 and SH-52 have antibiotic synthesis genes such as srfA, fenB, ituA, ituD, and bymA, which can inhibit hyphae growth and reduce the germination rate of pathogenic fungal spores, and have a strong inhibitory effect on a variety of pathogenic fungi.

[0024] The inventors of the present invention also found in their research that applying a fungicide made by mixing marigold extract, amino acids, humic acid and nutrients in a certain proportion and applying it to the rhizosphere soil of crops can improve the physical and chemical properties of the crop-growing soil, regulate the soil micronutrient structure, increase soil enzyme activity and microbial diversity, reduce the content of phenolic acid and fusaric acid in the soil, and promote the formation of soil microecological conditions that are conducive to the healthy growth of crops.

[0025] After further research, the inventors found that when Bacillus Velez SH-1471 and Bacillus subtilis SH-52 are applied to the rhizosphere soil of crops alone or together with the above-mentioned formula of the bacterial agent, it can further significantly improve the physical and chemical properties of the crop-growing soil, regulate the soil micronutrient structure, significantly increase soil enzyme activity and microbial diversity, significantly reduce the content of phenolic acid and fusaric acid in the soil, and significantly enhance the prevention and control effect of crop root rot.

[0026] Based on the above findings, the present invention provides a bacterial agent on one hand, the bacterial agent comprising:

[0027] Component 1: optional Bacillus Velez SH-1471 and Bacillus subtilis SH-52;

[0028] Component 2: marigold extract, amino acids, humic acid and nutrients.

[0029] That is, the bacterial agent formula provided by the present invention is any one of the following:

[0030] (1) Bacillus velez and Bacillus subtilis, marigold extract, amino acids, humic acid and nutrients;

[0031] (2) Marigold extract, amino acids, humic acid and nutrients.

[0032] The inventors have found in their research that when the components of the microbial agent are used in a specific weight ratio, the disease control effect is better. Therefore, according to a preferred embodiment of the present invention, the total amount of the Bacillus Velezii and Bacillus subtilis microbial agents is 1-5% by weight, preferably 2-5% by weight, and more preferably 3-5% by weight, based on the total weight of the microbial agent.

[0033] Preferably, the amount of the bacterial agent is such that the contents of Bacillus Velezii and Bacillus subtilis in the bacterial agent are 1×10 6 -2×10 8 cfu / g. Preferably 1×10 7 -2×10 8 cfu / g. More preferably 1×10 8 -2×10 8 cfu / g.

[0034] According to a preferred embodiment of the present invention, the weight ratio of marigold extract, amino acid, humic acid and nutrient elements is 5-10:5-10:78.5-89.5:0.5-2, preferably 6.5-10:6.5-10:78-86:1-2, and more preferably 8-10:8-10:78-82.5:1.5-2.0.

[0035] According to a preferred embodiment of the present invention, among the nutrient elements, P2O 5、 The weight ratio of K2O, calcium, magnesium, zinc and iron is 24-55:10-30:5-20:2-8:1.5-3.5:0.5-2.5, preferably 30-55:15-30:10-20:4-8:2.0-3.5:1.0-2.5, and more preferably 36-55:20-30:15-20:6-8:2.5-3.5:1.5-2.5.

[0036] According to a preferred embodiment of the present invention, the weight ratio of component 1 to component 2 is 1-5:95-99, preferably 2-5:95-98, and more preferably 3-5:95-97.

[0037] In the present invention, there is no particular limitation on the raw materials (such as marigold extract, amino acids, humic acid and nutrients) used as the above-mentioned bacterial agent, which can be any related product in the art that can be used to prepare bacterial agents, and can be either commercially available related products or related products prepared by themselves according to existing technologies.

[0038] The inventors found in their research that when specific raw materials are used, the disease control effect is better. Therefore, according to a preferred embodiment of the present invention, the water content in the marigold extract is 10-20% by weight; preferably 8-15%, and more preferably 5-10%.

[0039] Preferably, in the marigold extract, based on dry matter, the lutein content is 40-60% by weight, the flavonoid content is 5-10% by weight, and the carotenoid content is 1-2% by weight.

[0040] More preferably, in the marigold extract, based on dry matter, the lutein content is 55-60% by weight, the flavonoid content is 8-10% by weight, and the carotene content is 1.5-2% by weight.

[0041] According to a preferred embodiment of the present invention, the water content in the humic acid is 5-10% by weight, preferably 4-8% by weight, and more preferably 3-5% by weight.

[0042] According to a preferred embodiment of the present invention, the water content in the amino acid is 5-10% by weight, preferably 4-8% by weight, and more preferably 3-5% by weight.

[0043] The present invention further provides a method for preparing the above-mentioned bacterial agent. According to a preferred embodiment of the present invention, the method comprises uniformly mixing the marigold extract, amino acids, humic acid and nutrients of the above-mentioned component 2 to obtain a basic bacterial agent, and adding optional raw materials such as Bacillus Velezii and Bacillus subtilis (or their bacterial agents) to the basic bacterial agent according to the above-mentioned dosage ratio and mixing them evenly.

[0044] In the present invention, there is no particular restriction on the specific storage and use form of the microbial agent. Since the raw materials used in the microbial agent are basically solid, the preparation method is only to mix the components in proportion. Therefore, the microbial agent can be directly stored or used in the form of a solid preparation. Considering the differences in different crops or planting methods and planting conditions, the microbial agent can also be mixed with a certain amount of water to prepare a liquid or slurry (suspension) preparation for storage or use.

[0045] The Bacillus Velez and Bacillus subtilis provided in the second aspect of the present invention, or the bacterial agent described in the first aspect, are used to improve the physical and chemical properties of crop-growing soil, and / or to increase soil enzyme activity and microbial diversity, and / or to reduce the content of phenolic acid and Fusarium toxin in the soil, and / or to prevent and control crop root rot.

[0046] According to a preferred embodiment of the present invention, the crop is Olea europaea.

[0047] In the present invention, soil physicochemical properties refer to pH, alkaline nitrogen, available phosphorus, available potassium, exchangeable calcium and exchangeable magnesium; soil enzymes refer to enzymes such as urease, sucrase, acid phosphatase, β-1,4-glucosidase and β-1,4-acetylglucosaminidase; soil microbial diversity refers to Chao1, ACE, Shannon and Simpson indexes; soil phenolic acids refer to water-soluble phenolic acids, complex phenolic acids and total phenolic acids; soil Fusarium toxins refer to fumonisin B1, fumonisin B2 and fusaric acid.

[0048] In the present invention, controlling crop diseases refers to preventing or reducing the occurrence of crop diseases, or reducing the losses caused by the diseases after the diseases occur.

[0049] Preferably, the crop disease is selected from root rot, preferably root rot of Euphorbia cerasifera.

[0050] According to some preferred embodiments of the present invention, the pathogen causing the root rot of the golden fruit olive is Fusarium ( Fusarium solani ) and oomycetes ( Pythium aphanidermatum ).

[0051] The third aspect of the present invention provides a method for preparing and using a microbial agent for preventing and controlling crop root rot, the method comprising applying the agent described in the first aspect to the rhizosphere soil of the crop.

[0052] That is, the above method may include the following ways:

[0053] (1) Applying Bacillus Velez and / or Bacillus subtilis directly to the rhizosphere soil of crops (usually, this can be done by directly applying solid bacterial agents to the rhizosphere soil of crops, or culturing Bacillus Velez and / or Bacillus subtilis and then applying the culture to the soil);

[0054] (2) Applying a bacterial agent that does not contain Bacillus Velezii and / or Bacillus subtilis to the rhizosphere soil of crops;

[0055] (3) Applying a microbial agent containing Bacillus Velez and / or Bacillus subtilis to the rhizosphere soil of crops.

[0056] In the present invention, the crop is Olea europaea.

[0057] Preferably, the pathogen causing the root rot of the golden fruit olive is Fusarium ( Fusarium solani ) and oomycetes ( Pythium aphanidermatum ).

[0058] The specific characteristics of the Bacillus Velezii and / or Bacillus subtilis and the bacterial agent used in the method provided by the present invention are as described above and will not be repeated here.

[0059] In the present invention, there is no particular limitation on the specific dosage of Bacillus Velez and / or Bacillus subtilis and the bacterial agent, as long as the root rot can be prevented and treated.

[0060] According to a preferred embodiment of the present invention, in the above method (1), the amount of Bacillus Velezii and / or Bacillus subtilis is such that the content of bacteria in the bacterial agent is 1×10 8 -2×10 8 The dosage of Bacillus Velez and / or Bacillus subtilis is calculated according to the dosage of the bacterial agent and the quantity of Bacillus Velez and / or Bacillus subtilis contained therein, wherein the liquid bacterial agent is converted according to 1 g / mL.

[0061] The inventors of the present invention have also found in their research that when planting different crops, the dosage of the aforementioned Bacillus Velez and / or Bacillus subtilis or bacterial agent is also adjusted accordingly, which can further improve the systemic resistance and disease prevention effects of the crops.

[0062] According to some preferred embodiments of the present invention, for the above method (1):

[0063] When applied to the rhizosphere soil of crops, the total amount of the Velez subtilis and / or Bacillus subtilis is not less than 2×10 8 cfu / strain / time. Preferably 2×10 8 -2×10 9 cfu / strain / time. More preferably 2×10 8 -8×10 8 cfu / strain / time. More preferably, 3×10 8 -6×10 8 cfu / plant / time.

[0064] The bacterial agent provided by the present invention has a synergistic effect when used together with Bacillus Velez and / or Bacillus subtilis. Therefore, when adopting the above-mentioned method (1), in order to obtain a better effect, the amount of Bacillus Velez and / or Bacillus subtilis used can be appropriately increased compared with the amount of Bacillus Velez and / or Bacillus subtilis applied with the bacterial agent in method (3).

[0065] Preferably, for the above method (3):

[0066] When applied to crops, the total amount of the Bacillus Velez and / or Bacillus subtilis is not less than 1×10 10 cfu / strain / time, preferably 1.2×10 10 cfu / strain / time, more preferably 1.5×10 10 cfu / strain / time, more preferably 2×10 10 cfu / plant / time.

[0067] According to some preferred embodiments of the present invention, for the above-mentioned methods (2) and (3), the amount of the microbial agent applied to the crop planting soil may be 100-200 g / plant / time. For example, it may be 100 g / plant / time, 120 g / plant / time, 140 g / plant / time, 160 g / plant / time, 180 g / plant / time, 200 g / plant / time, or any intermediate value between any two of the above values.

[0068] The present invention will be described in detail below by way of examples. It should be understood that the following examples are only used to further explain and illustrate the present invention, and are not intended to limit the present invention. Example

[0069] The marigold extract used in this example was purchased from Xi'an An'ao Biotechnology Co., Ltd., amino acids were purchased from Shandong Ruizhaoyuan Biotechnology Co., Ltd., humic acid was purchased from Shanxi Jiayou Humic Acid Technology Co., Ltd., and P2O5, K2O, calcium, magnesium, zinc, and iron were purchased from Shandong Mingwei Chemical Co., Ltd. The microbial agent was a liquid culture obtained by expanding Bacillus Velez SH-1471 (for the acquisition method, please refer to CN 202211479280.X) and Bacillus subtilis SH-52 (for the acquisition method, please refer to CN 202211479391.0), wherein the content of Bacillus Velez was 1.5×10 8 cfu / g, Bacillus subtilis content is 1.5×10 8 cfu / ml.

[0070] Table 1 shows the test results of the raw material components used in the preparation of basic bacterial agents, among which the contents of lutein, flavonoids, carotenoids and vitamins were determined by high performance liquid chromatography, the phosphorus content (measured in P2O5) was determined by molybdenum antimony colorimetry, the potassium content (measured in K2O) was determined by flame photometry, the calcium and magnesium contents were determined by EDTA titration, the zinc content was determined by flame atomic absorption spectrometry, and the iron content was determined by o-phenanthroline colorimetry.

[0071] Table 1 Basic organic fertilizer material composition

[0072]

[0073] The microbial agent was prepared according to the formula in Table 2. The specific preparation method included: weighing the raw materials according to the proportions in Table 2, and mixing them evenly to obtain the microbial agent (solid preparation).

[0074] Table 2 Microbial agent formula

[0075]

[0076] According to a preferred embodiment of the present invention, the application frequency of the Bacillus Velez and Bacillus subtilis inoculants is 1-3 times per crop.

[0077] In order to obtain better disease prevention effect, according to some preferred embodiments of the present invention, when the Bacillus Velez and Bacillus subtilis agents are applied to the golden olive, fertilizer is applied once every 10-15 days starting from the time of planting, for a total of 3 applications.

[0078] According to the formula of the microbial agent in Table 2, fertilization was carried out at an application rate of 100-200 g / plant / time (50 plants were planted in each test group), so that the total amount of Bacillus velezium and Bacillus subtilis in the microbial agent was not less than 2×10 8cfu / plant / time; the control effect of various diseases was investigated during the harvest period, and the main physical and chemical properties of the rhizosphere soil of the plants, the enzyme activity, microbial diversity of the rhizosphere soil, and the contents of phenolic acid and fusaric acid in the soil were determined.

[0079] Investigation and grading standards for root rot of golden olive:

[0080] Level 0, healthy roots, no disease symptoms;

[0081] Level 1, slight root damage, with a small amount of lesions visible (0-10%);

[0082] Level 2, there are some lesions on the roots (11% to 25%);

[0083] Level 3, moderate damage, root lesions spread (26% to 50%);

[0084] Level 4, severe damage, most of the root is infected, with very little uninfected tissue (51% to 75%);

[0085] Level 5: Very serious, the roots are completely infected and the plant may die (76% to 100%).

[0086] The control effect is calculated using the following two formulas:

[0087] Disease index = [(Σ(number of diseased plants × representative level)) / (total number of plants × highest representative level)] × 100

[0088] Control effect (%) = [(control group disease index - treatment group disease index) / control group disease index] × 100%

[0089] Determination of soil physical and chemical properties: soil pH was determined by potentiometric method, soil alkaline nitrogen was determined by alkaline hydrolysis distillation method, soil available phosphorus was determined by molybdenum antimony colorimetry, soil available potassium was determined by flame photometer method, and soil exchangeable calcium and exchangeable magnesium contents were determined by EDTA titration method.

[0090] Soil enzyme activity determination: The activities of soil urease, sucrase, acid phosphatase, β-1,4-glucosidase and β-1,4-acetylglucosaminidase were determined using kits purchased from Suzhou Greis Biotechnology Co., Ltd. The usage method refers to the instructions.

[0091] Determination of soil microbial diversity: Soil microbial total DNA was extracted using the OMEGA soil total DNA extraction kit according to the operating instructions. The quality of DNA extraction was detected by 0.8% agarose gel electrophoresis, and DNA was quantified by UV spectrophotometer. Qualified DNA was sent to Meiji Biotechnology Co., Ltd. for high-throughput sequencing. The original sequencing data was identified, checked and chimera sequences were removed by query sequence to obtain valid sequences of the samples. The sequence with the highest abundance in each OTU was used as the representative sequence of the OTU. OTUs were merged and divided based on 97% sequence similarity to construct the OTU abundance matrix in each sample. According to the results of the OTU abundance matrix, the number of common OTUs in each sample was calculated; the Chao1 richness index and ACE index were used to evaluate the richness of the microbial community; the Shannon diversity index and Simpson diversity index were used to evaluate the uniformity of the microbial community.

[0092] Determination of soil phenolic acid content: The contents of water-soluble phenolic acid, complex phenolic acid and total phenolic acid were determined by high performance liquid chromatography (HPLC).

[0093] Determination of soil Fusarium toxin content: The content of soil fumonisin B1, fumonisin B2 and fusaric acid was determined by high performance liquid chromatography (HPLC).

[0094] From the data in Tables 3, 4, 5, 6, 7, 8, and 9, it can be seen that when the microbial agent provided by the present invention is applied, the prevention and control effect on root rot is significantly higher than that of the control; the improvement of soil physicochemical properties, soil enzyme activity, and soil microbial diversity index is also stronger than that of the control; in addition, the application of the microbial agent provided by the present invention significantly reduces the content of soil phenolic acid and Fusarium toxin, thereby achieving the purpose of preventing and controlling root rot.

[0095] Table 3 Test conditions and results of the microbial agent test on the control effect of golden olive root rot

[0096]

[0097] *The control group is a blank control group without any bacterial agent, and the fertilizer group is a control group with the chemical fertilizer of component 2 in the example.

[0098] Table 4 Test conditions and results of microbial agents on the physical and chemical properties of soil for growing golden olives

[0099]

[0100] *The control group is a blank control group without any bacterial agent, and the fertilizer group is a control group with the chemical fertilizer of component 2 in the example.

[0101] Table 5 Test conditions and results of microbial agents on soil enzyme activity in the cultivation of golden fruit olive

[0102]

[0103] *The control group is a blank control group without any bacterial agent, and the fertilizer group is a control group with the chemical fertilizer of component 2 in the example.

[0104] Table 6 Test conditions and results of microbial agents on soil bacterial diversity in the cultivation of golden olives

[0105]

[0106] *The control group is a blank control group without any bacterial agent, and the fertilizer group is a control group with the chemical fertilizer of component 2 in the example.

[0107] Table 7 Test conditions and results of microbial agents on soil fungal diversity in the cultivation of golden fruit olive

[0108]

[0109] *The control group is a blank control group without any bacterial agent, and the fertilizer group is a control group with the chemical fertilizer of component 2 in the example.

[0110] Table 8 Test conditions and results of microbial agents on phenolic acid content in soil of golden olive cultivation

[0111]

[0112] *The control group is a blank control group without any bacterial agent, and the fertilizer group is a control group with the chemical fertilizer of component 2 in the example.

[0113] Table 9 Test conditions and results of microbial agents on the content of Fusarium toxins in soil of golden olive cultivation

[0114]

[0115] *The control group is a blank control group without any bacterial agent, and the fertilizer group is a control group with the chemical fertilizer of component 2 in the example.

[0116] Finally, it should be noted that the above preferred embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail through the above preferred embodiments, those skilled in the art should understand that various changes can be made in form and details without departing from the scope defined by the claims of the present invention.

Claims

1. A microbial agent for preventing and controlling root rot of golden olive in the degradation of soil phenolic acid, regulation of soil microbial diversity, enhancement of soil enzyme activity, and reduction of soil fusarium toxins, characterized in that: The bacterial agent comprises the following components: Bacillus Velezii with a preservation number of CCTCC No: M2022923 ( Bacillus velezensis ), Bacillus subtilis with a deposit number of CCTCCNo: M20221207 ( Bacillus subtilis ), marigold extract, amino acids, humic acid and nutrients; wherein the soil phenolic acid refers to: total phenolic acid, complex phenolic acid and water-soluble phenolic acid; the soil enzyme activity refers to: urease, sucrase, acid phosphatase, β-1,4-glucosidase and β-1,4-acetylglucosaminidase; the microbial diversity refers to: ACE index, Chao I index, Simpson index and Shannon index of fungi and bacteria in the soil.

2. The use according to claim 1, characterized in that: The amount of Bacillus Velez in the bacterial agent is such that the content of Bacillus Velez in the bacterial agent is 1×10 8 -2×10 8 cfu / g; the amount of Bacillus subtilis in the bacterial agent is such that the content of Bacillus subtilis in the bacterial agent is 1×10 8 -2×10 8 cfu / g.

3. The use according to claim 1, characterized in that: The weight ratio of the marigold extract, amino acid, humic acid and nutrient elements is 5-10:5-10:78-89:1-2; the nutrient elements include P2O 5、 K2O, calcium, magnesium, zinc and iron, wherein the weight ratio of P2O5, K2O, calcium, magnesium, zinc and iron is 36-55:20-30:15-20:6-8:2.5-3.5:1.5-2.

5.

4. The use according to claim 1, characterized in that: The total dosage of the Bacillus Velez and Bacillus subtilis inoculants is 3%-5% of the total weight of the inoculants.

5. The use according to any one of claims 1 to 4, characterized in that: The marigold extract has a water content of 10-20% by weight; based on dry matter, the lutein content is 40-60% by weight, the flavonoid content is 5-10% by weight, and the carotenoid content is 1-2% by weight; and / or, the humic acid has a water content of 5-10% by weight; And / or, the amino acid has a water content of 5-10% by weight.

6. The use according to claim 5, characterized in that: The root rot of the golden fruit olive is selected from the group consisting of Fusarium spp. Fusarium solani ) root rot and oomycetes ( Pythium aphanidermatum ) root rot; wherein the pathogen causing the root rot of the golden fruit olive is Fusarium ( Fusarium solani ) and oomycetes ( Pythium aphanidermatum ).

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