Compound antibacterial agent for flue-cured tobacco plant growth and preparation method thereof

Abstract

The invention discloses a compound antibacterial agent for flue-cured tobacco plant growth and a preparation method of the compound antibacterial agent, and belongs to the technical field of antibacterial agents. Comprising the following components in percentage by weight: 0.5%-2.0% of chlorin (III) chelate, 0.05%-0.1% of kasugamycin, 0.15%-0.25% of dimethomorph, 6%-8% of polyglycerol fatty acid ester, 4%-5% of an organic silicon surfactant, 2%-4% of an anti-freezing agent, 10% of an organic solvent and the balance of pure water. According to the invention, the chlorin (III) chelate is compounded with kasugamycin and dimethomorph for the first time, and disease prevention and control are realized through double paths of immune activation and targeted sterilization. Through detection, the comprehensive control effect of the compound antibacterial agent on bacterial wilt and black shank reaches 80.3%-94.7% and is obviously higher than that of a single-agent control group (the control effect lt; 55%), and the synergistic interaction of the chlorin (III) chelate and the bactericide is proved.

Description

Technical Field

[0001] The invention belongs to the technical field of antimicrobial agents, and in particular relates to a compound antimicrobial agent for growing flue-cured tobacco plants and a preparation method thereof. Background Art

[0002] Flue-cured tobacco is an important economic crop in my country. It is susceptible to a variety of diseases during its growth. Tobacco bacterial wilt (caused by Ralstonia solanacearum) and tobacco black shank (caused by Phytophthoranicotianae) are typical soil-borne diseases that can cause stem rot, leaf wilting and root necrosis, seriously reducing tobacco yield and quality. Existing prevention and control measures mainly rely on chemical antimicrobial agents, but long-term single use can easily lead to pathogen resistance and have limited regulatory effects on tobacco growth.

[0003] Dihydrochlorin iron (III) chelate is a new type of plant immune inducer that can enhance crop stress resistance by activating plant systemic resistance (SAR), while regulating endogenous hormones (such as inhibiting indoleacetic acid oxidase activity) and promoting root development.

[0004] Studies have shown that the scientific combination of plant growth regulators and antimicrobial agents can significantly enhance the synergistic effect. However, there is currently no research on the combination of dihydrochlorin iron (III) chelates and antimicrobial agents for the prevention and control of flue-cured tobacco diseases. Summary of the invention

[0005] The present invention provides a compound antibacterial agent for the growth of flue-cured tobacco plants and a preparation method thereof. The present invention aims to develop a compound agent with both growth promotion and high-efficiency antibacterial properties, which is of great significance for achieving the goals of green production of flue-cured tobacco and reduction of both pesticides and fertilizers.

[0006] The purpose of the present invention can be achieved through the following technical solutions:

[0007] A composite antibacterial agent for the growth of flue-cured tobacco plants, comprising the following components by weight percentage:

[0008] 0.5% to 2.0% dihydrochlorin iron (III) chelate, 0.05% to 0.1% kasugamycin, 0.15% to 0.25% enoylmorpholine, 6% to 8% polyglycerol fatty acid ester, 4% to 5% silicone surfactant, 2% to 4% antifreeze agent, 10% organic solvent, and the balance is pure water.

[0009] Furthermore, the compound antibacterial agent comprises the following components by weight percentage:

[0010] 2.0% dihydrochlorin iron (III) chelate, 0.1% kasugamycin, 0.25% enoylmorpholine, 8% polyglycerol fatty acid ester, 5% silicone surfactant, 4% antifreeze agent, 10% organic solvent, and the balance is pure water.

[0011] Furthermore, the chemical structural formula of the dihydrochlorin iron (III) chelate is as follows:

[0012] .

[0013] Furthermore, in the chemical structure formula of the dihydrochlorin iron (III) chelate: R=K; X=OCOCH3.

[0014] Furthermore, the organosilicon surfactant is the organosilicon surfactant Silwet L-77.

[0015] Furthermore, the antifreeze agent is ethylene glycol, propylene glycol or glycerol.

[0016] Furthermore, the organic solvent is methanol, acetone or cyclohexanone.

[0017] Furthermore, the preparation method of the compound antibacterial agent for the growth of flue-cured tobacco plants comprises the following steps: weighing each raw material according to mass percentage, mixing polyglycerol fatty acid ester, silicone surfactant and organic solvent, adding dihydrochlorin iron (III) chelate, kasugamycin and enoylmorpholine thereto, stirring and mixing at room temperature for 0.1 to 2 hours to obtain a main agent; adding an antifreeze agent to pure water, stirring and mixing at room temperature for 0.1 to 2 hours to obtain an auxiliary agent; pouring the main agent into the auxiliary agent, stirring at room temperature for 0.1 to 2 hours to obtain a compound antibacterial agent for the growth of flue-cured tobacco plants.

[0018] Beneficial effects of the present invention:

[0019] (1) Construction of synergistic enhancement system: The present invention is the first to compound dihydrochlorin iron (III) chelate with kasugamycin and dimethomorph, and achieve disease prevention and control through the dual pathways of "immune activation + targeted sterilization". Among them, dihydrochlorin iron (III) chelate is used as a plant immune inducer, which activates the salicylic acid (SA) and jasmonic acid (JA) signaling pathways to enhance the systemic resistance of flue-cured tobacco to Ralstonia solanacearum (bacteria) and Phytophthora nicotianae (oomycete). The K coordination with the OCOCH3 substituent in the structural formula can enhance lipid solubility and promote transmembrane absorption; kasugamycin is specifically effective in preventing and controlling Gram-negative bacteria (such as Ralstonia solanacearum) by inhibiting the 30S ribosomal subunit to block protein synthesis; dimethomorph targets the cellulose synthase (CESA3) of oomycetes (such as Phytophthora nicotianae) to inhibit cell wall formation. After testing, the comprehensive prevention effect of the compound antibacterial agent on bacterial wilt and black leg disease reached 80.3% to 94.7%, which was significantly higher than the single-dose control group (prevention effect <55%), proving the synergistic effect of dihydrochlorin iron (III) chelate and fungicide. At the same time, the per-acre yield of tobacco leaves treated with compound antibacterial agents increased by 18.6% to 26.5%, and the nicotine content was optimized to 2.68% to 3.02%, meeting the standards for high-quality tobacco leaves (2.5% to 3.5%). Finally, the present invention breaks through the bottleneck of insufficient prevention effect of traditional agents on soil-borne diseases by combining targeted sterilization (kasugamycin targets solanacearum and oxadimethoxine inhibits phytophthora) with systemic resistance induction.

[0020] (2) Surfactant-directed optimization: The present invention adopts a composite system of polyglycerol fatty acid ester and Silwet L-77 to break through the limitation of traditional sulfonate dispersants on vascular bundle penetration.

[0021] (3) Low-dose, high-efficiency formula: The dosage of kasugamycin (0.05% to 0.1%) is significantly lower than the conventional single-dose recommended concentration (0.2% to 0.3%), achieving drug reduction and increased efficacy through synergistic effects. DETAILED DESCRIPTION

[0022] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0023] Example 1

[0024] A compound antibacterial agent for growing flue-cured tobacco plants and a preparation method thereof:

[0025] First, the above-mentioned composite antibacterial agent includes the following components by weight percentage: 0.5% dihydrochlorin iron (III) chelate, 0.05% kasugamycin, 0.15% oxadimethoxine, 6% polyglycerol fatty acid ester, 4% silicone surfactant Silwet L-77, 2% antifreeze agent ethylene glycol, 10% methanol, and the balance is pure water, wherein the chemical structure of dihydrochlorin iron (III) chelate is as follows:

[0026]

[0027] Among them, R=K; X=OCOCH3.

[0028] Then, the preparation method of the above-mentioned compound antibacterial agent includes the following steps: weighing each raw material according to mass percentage, mixing polyglycerol fatty acid ester, silicone surfactant Silwet L-77 and methanol, then adding dihydrochlorin iron (III) chelate, kasugamycin and enoylmorpholine thereto, stirring and mixing at room temperature for 0.1h to obtain a main agent; then adding antifreeze agent ethylene glycol to pure water, stirring and mixing at room temperature for 0.1h to obtain an auxiliary agent; pouring the main agent into the auxiliary agent, stirring at room temperature for 0.1h, and obtaining a compound antibacterial agent for the growth of flue-cured tobacco plants.

[0029] Example 2

[0030] A compound antibacterial agent for growing flue-cured tobacco plants and a preparation method thereof:

[0031] First, the above-mentioned composite antibacterial agent includes the following components by weight percentage: 1.0% dihydrochlorin iron (III) chelate, 0.08% kasugamycin, 0.20% oxadimethoxine, 7% polyglycerol fatty acid ester, 4% silicone surfactant Silwet L-77, 3% antifreeze agent propylene glycol, 10% acetone, and the balance is pure water, wherein the chemical structure of dihydrochlorin iron (III) chelate is as follows:

[0032]

[0033] Among them, R=K; X=OCOCH3.

[0034] Then, the preparation method of the above-mentioned compound antibacterial agent includes the following steps: weighing each raw material according to mass percentage, mixing polyglycerol fatty acid ester, silicone surfactant Silwet L-77 and acetone, adding dihydrochlorin iron (III) chelate, kasugamycin and enoylmorpholine thereto, stirring and mixing at room temperature for 1 hour to obtain a main agent; adding antifreeze agent propylene glycol to pure water, stirring and mixing at room temperature for 1 hour to obtain an auxiliary agent; pouring the main agent into the auxiliary agent, stirring at room temperature for 1 hour, and obtaining a compound antibacterial agent for the growth of flue-cured tobacco plants.

[0035] Example 3

[0036] A compound antibacterial agent for growing flue-cured tobacco plants and a preparation method thereof:

[0037] First, the above-mentioned composite antibacterial agent includes the following components by weight percentage: 2.0% dihydrochlorin iron (III) chelate, 0.1% kasugamycin, 0.25% oxadimethoxine, 8% polyglycerol fatty acid ester, 5% silicone surfactant Silwet L-77, 4% antifreeze agent glycerol, 10% cyclohexanone, and the balance is pure water, wherein the chemical structure of dihydrochlorin iron (III) chelate is as follows:

[0038]

[0039] Among them, R=K; X=OCOCH3.

[0040] Then, the preparation method of the above-mentioned compound antibacterial agent includes the following steps: weighing each raw material according to mass percentage, mixing polyglycerol fatty acid ester, silicone surfactant Silwet L-77 and cyclohexanone, and then adding dihydrochlorin iron (III) chelate, kasugamycin and enoylmorpholine thereto, stirring and mixing at room temperature for 2 hours to obtain a main agent; then adding antifreeze agent glycerol to pure water, stirring and mixing at room temperature for 2 hours to obtain an auxiliary agent; pouring the main agent into the auxiliary agent, stirring at room temperature for 2 hours, and obtaining a compound antibacterial agent for the growth of flue-cured tobacco plants.

[0041] Comparative Example 1

[0042] Comparative Example 1 is the control group of Example 3, in which 2.0% dihydrochlorin iron (III) chelate and 0.1% kasugamycin in the compound antibacterial agent in Example 3 are removed, and the amounts of the other components remain unchanged (except pure water), that is, the compound antibacterial agent includes the following components: 0.25% ethoxymorphone, 8% polyglycerol fatty acid ester, 5% silicone surfactant Silwet L-77, 4% antifreeze agent glycerol, 10% cyclohexanone, and the balance is pure water. At the same time, the preparation method is completely consistent with that in Example 3, and finally a compound antibacterial agent for the growth of flue-cured tobacco plants is obtained.

[0043] Comparative Example 2

[0044] Comparative Example 2 is the control group of Example 3, in which 2.0% of dihydrochlorin iron (III) chelate and 0.25% of ethylenediaminetetracycline in the compound antibacterial agent in Example 3 are removed, and the amounts of the other components remain unchanged (except for pure water), that is, the compound antibacterial agent includes the following components: 0.1% kasugamycin, 8% polyglycerol fatty acid ester, 5% silicone surfactant Silwet L-77, 4% antifreeze agent glycerol, 10% cyclohexanone, and the balance is pure water. At the same time, the preparation method is completely consistent with that in Example 3, and finally a compound antibacterial agent for the growth of flue-cured tobacco plants is obtained.

[0045] Comparative Example 3

[0046] Comparative Example 3 is the control group of Example 3, in which 0.1% kasugamycin and 0.25% oxadimethoxine in the compound antibacterial agent in Example 3 are removed, and the amounts of the other components remain unchanged (except pure water), that is, the compound antibacterial agent includes the following components: 2.0% dihydrochlorin iron (III) chelate, 8% polyglycerol fatty acid ester, 5% silicone surfactant Silwet L-77, 4% antifreeze agent glycerol, 10% cyclohexanone, and the balance is pure water. At the same time, the preparation method is completely consistent with that in Example 3, and finally a compound antibacterial agent for the growth of flue-cured tobacco plants is obtained.

[0047] The performance test was performed on the composite antibacterial agents prepared in Examples 1 to 3 and Comparative Examples 1 to 3. The performance test process is as follows, and the test results are shown in Table 1:

[0048] 1. Test strains: Tobacco bacterial wilt pathogen (Ralstonia solanacearum strain YN-2023-01), isolated and identified by the Institute of Plant Protection, Yunnan Academy of Agricultural Sciences; Tobacco black shank pathogen (Phytophthora nicotianae strain KM-2023-02), provided by Yunnan Tobacco Science Research Institute.

[0049] 2. Experimental tobacco: Yunyan No. 87 (main cultivated variety), provided by Yunnan Tobacco Seed Co., Ltd., and transplanted to the experimental field after seedling raising.

[0050] 3. Experimental agents: The flue-cured tobacco composite antibacterial agents prepared in Examples 1 to 3 and Comparative Examples 1 to 3, wherein: dihydrochlorin iron (III) chelate was purchased from Nanjing Better Biotechnology Co., Ltd.; kasugamycin was purchased from Japan Hokuko Chemical Industry Co., Ltd.; and oxadimethoxine was purchased from Jiangsu Qizhou Green Chemical Co., Ltd.

[0051] 4. Field test process and results:

[0052] (1) Experimental field setting: The experimental site is located in the tobacco planting base of Guishan Town, Shilin Yi Autonomous County, Kunming City. The area of ​​a single experimental field is 50m 2 The soil is red soil (pH 5.8, organic matter content 18g / kg). Before tobacco transplanting, apply tobacco-specific fertilizer (N:P:K=10:12:20) 900kg / hm 2 , planting row spacing 120cm, plant spacing 50cm, density 16500 plants / hm 2 .

[0053] (2) Pathogen inoculation and pesticide treatment:

[0054] a. Inoculation method: Tobacco bacterial wilt pathogen: 30 days after transplanting (vigorous period), inoculate the bacterial suspension (1×108 CFU / mL) root inoculation, 20 mL per plant; tobacco black shank pathogen: 5 days after inoculation, spray the sporangium suspension (1×10 5 / mL) at the base of the stem.

[0055] b. Application plan:

[0056] Experimental group: The compound antimicrobial agent was diluted 10,000 times (agent: water = 1:9999), and the first foliar spraying and stem base root irrigation were carried out 7 days after inoculation (the dosage of the liquid was 500 kg / hm 2 ), twice applied with an interval of 15 days; control group: sprayed with an equal amount of water; each group was repeated 3 times in the test fields, arranged in random blocks.

[0057] (3) Investigation and calculation:

[0058] Disease assessment: 15 days after the last application of pesticide, survey all plants in the field and record the number of diseased plants.

[0059] Bacterial wilt disease rate (%) = (number of plants with browning and wilting at the stem base / total number of plants investigated) × 100%;

[0060] Black shank disease rate (%) = (number of plants with stem base rot and white mycelium / total number of plants investigated) × 100%;

[0061] Comprehensive control effect (%) = (disease rate in the control group - disease rate in the treatment group) / disease rate in the control group × 100%.

[0062] Yield increase assessment: Determine tobacco leaf yield and quality after harvesting.

[0063] Yield increase rate (%) = (yield per mu of treatment group - yield per mu of control group) / yield per mu of control group × 100%;

[0064] Nicotine content: High performance liquid chromatography (HPLC) was used to detect the middle tobacco leaves.

[0065] Table 1 Test results

[0066] Group Rate of bacterial wilt diseased plants (%) Black shank disease rate (%) Comprehensive prevention effect (%) Yield per mu (kg) Yield increase rate (%) Nicotine content (%) Example 1 10.5 8.2 80.3 158.4 18.6 2.68 Example 2 7.8 6.5 87.5 165.2 23.1 2.83 Example 3 4.3 3.5 94.7 178.6 26.5 3.02 Comparative Example 1 32.6 25.7 45.5 142.3 7.1 2.41 Comparative Example 2 28.4 29.1 52.8 138.9 4.6 2.35 Comparative Example 3 41.5 37.2 32.5 130.2 -2.1 2.18 Control group 60.2 58.4 / 132.8 / 2.14

[0067] analyze:

[0068] 1. Disease prevention and control effect

[0069] (1) Gradient of Examples 1 to 3: With the increase of the concentration of chlorin iron (III) chelate, kasugamycin and dimethomorph, the control effect was significantly improved. The comprehensive control effect of Example 3 (2.0%+0.1%+0.25%) reached 94.7%.

[0070] Synergistic effect: Dihydrochlorin iron (III) chelate activates plant systemic resistance (SA / JA pathway), kasugamycin targets Ralstonia solanacearum (inhibits protein synthesis), and enoylmorph inhibits cell wall synthesis of Phytophthora, with a triple mechanism superimposed.

[0071] Surfactant enhancement: High proportion of polyglycerol fatty acid ester (8%) + Silwet L-77 (5%) improves the permeability of the solution and enhances the absorption efficiency of the stem base and roots.

[0072] (2) Comparative Example 3 (only dihydrochlorin iron (III) chelate): The comprehensive protective effect was 32.5%, indicating that the immune inducer alone could not completely kill the pathogens and needed to be used in conjunction with the bactericide.

[0073] 2. Increase production and improve quality

[0074] (1) Yield increase gradient: Example 3 increased by 26.5% > Example 2 (23.1%) > Example 1 (18.6%), which is consistent with the prevention effect trend. After the disease is reduced, nutrients are transferred to the tobacco leaves, and the single leaf weight increases.

[0075] Nicotine content: Example 3 reached 3.02%, significantly higher than the control group (2.14%), because the expression of nicotine synthesis genes (such as NtPMT) in healthy plants was upregulated.

[0076] (2) Yield reduction in comparison group: Comparison group 3 (-2.1%) suffered from severe disease, which resulted in loss of photosynthetic assimilates, verifying the strong correlation between disease prevention and yield increase.

[0077] in conclusion:

[0078] (1) Disease prevention and control: The comprehensive prevention effect of the compound antibacterial agents of Examples 1 to 3 on bacterial wilt and black leg disease reached 80.3% to 94.7%, which was significantly higher than that of the single-dose control group (prevention effect <55%), proving the synergistic effect of dihydrochlorin iron (III) chelate and fungicide.

[0079] (2) Increased yield and improved quality: The per-acre yield of tobacco leaves in the treatment group increased by 18.6% to 26.5%, and the nicotine content was optimized to 2.68% to 3.02% (only 2.14% in the control group), meeting the standards for high-quality tobacco leaves (2.5% to 3.5%).

[0080] Note: This experiment complies with the "Guidelines for Field Efficacy Tests of Pesticides" (GB / T 17980.12-2022), and the data were analyzed by ANOVA using SPSS26.0 software (P<0.01).

[0081] It should be noted that, in this article, terms such as "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article or equipment that includes a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or equipment.

[0082] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A composite antibacterial agent for the growth of flue-cured tobacco plants, characterized in that: Calculated by weight percentage, the invention comprises the following components: 0.5% to 2.0% of dihydrochlorin iron (III) chelate, 0.05% to 0.1% of kasugamycin, 0.15% to 0.25% of enoylmorpholine, 6% to 8% of polyglycerol fatty acid ester, 4% to 5% of silicone surfactant, 2% to 4% of antifreeze agent, 10% of organic solvent, and the balance is pure water.

2. The compound antibacterial agent for growing flue-cured tobacco plants according to claim 1, characterized in that: The compound antibacterial agent comprises the following components by weight percentage: 2.0% of dihydrochlorin iron (III) chelate, 0.1% of kasugamycin, 0.25% of enoylmorpholine, 8% of polyglycerol fatty acid ester, 5% of silicone surfactant, 4% of antifreeze agent, 10% of organic solvent, and the balance is pure water.

3. The compound antibacterial agent for growing flue-cured tobacco plants according to claim 1, characterized in that: The chemical structural formula of the chlorin iron (III) chelate is as follows: 。 4. The compound antibacterial agent for growing flue-cured tobacco plants according to claim 1, characterized in that: In the chemical structural formula of the dihydrochlorin iron (III) chelate: R=K; X=OCOCH3.

5. The compound antibacterial agent for growing flue-cured tobacco plants according to claim 1, characterized in that: The organosilicon surfactant is the organosilicon surfactant Silwet L-77.

6. The compound antibacterial agent for growing flue-cured tobacco plants according to claim 1, characterized in that: The antifreeze agent is ethylene glycol, propylene glycol or glycerol.

7. The compound antibacterial agent for growing flue-cured tobacco plants according to claim 1, characterized in that: The organic solvent is methanol, acetone or cyclohexanone.

8. The method for preparing a composite antibacterial agent for growing flue-cured tobacco plants according to any one of claims 1 to 7, characterized in that: The method comprises the following steps: weighing various raw materials according to mass percentage, mixing polyglycerol fatty acid ester, organosilicon surfactant and organic solvent, adding dihydrochlorin iron (III) chelate, kasugamycin and enoylmorpholine thereto, stirring and mixing at room temperature for 0.1 to 2 hours to obtain a main agent; adding an antifreeze agent to pure water, stirring and mixing at room temperature for 0.1 to 2 hours to obtain an auxiliary agent; pouring the main agent into the auxiliary agent, stirring at room temperature for 0.1 to 2 hours to obtain a composite antibacterial agent for the growth of flue-cured tobacco plants.

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