A compound antibacterial agent for flue-cured tobacco plant growth and its preparation method

Abstract

The present invention discloses a compound antibacterial agent for flue-cured tobacco plant growth and its preparation method, belonging to the technical field of antibacterial agents. First of all, the compound antibacterial agent for flue-cured tobacco plant growth, calculated by weight percentage, comprises the following components: 0.5% - 2.0% of chlorophyllin iron(III) chelate, 0.05% - 0.1% of kasugamycin, 0.15% - 0.25% of dimethomorph, 6% - 8% of polyglycerol fatty acid ester, 4% - 5% of organosilicon surfactant, 2% - 4% of antifreeze, 10% of organic solvent, and the balance is pure water. The present invention first combines chlorophyllin iron(III) chelate with kasugamycin and dimethomorph, and realizes disease prevention and control through the "immune activation + targeted sterilization" double path. Through detection, the comprehensive control effect of the compound antibacterial agent on bacterial wilt and black shank diseases reaches 80.3% - 94.7%, which is significantly higher than that of the single-agent control group (control effect < 55%), proving the synergistic effect of chlorophyllin iron(III) chelate and the bactericide.

Description

Technical Field

[0001] The present invention belongs to the technical field of antibacterial agents, and particularly relates to a compound antibacterial agent for flue-cured tobacco plant growth and a preparation method thereof. Background Art

[0002] Flue-cured tobacco is an important cash crop in China. During its growth process, it is vulnerable to various diseases. Among them, tobacco bacterial wilt (caused by Ralstonia solanacearum) and tobacco black shank (caused by Phytophthora nicotianae) are typical soil-borne diseases, which can lead to stem base rot, leaf wilting and root necrosis of tobacco plants, seriously reducing the yield and quality of tobacco leaves. The existing control measures mainly rely on chemical antibacterial agents, but long-term single use is likely to cause pathogen drug resistance and has limited effect on the growth regulation of tobacco plants.

[0003] Chlorophyllin iron(III) chelate is a new type of plant immune inducer, which can enhance the stress resistance of crops by activating the systemic acquired resistance (SAR) of plants, and at the same time regulate endogenous hormones (such as inhibiting the activity of indoleacetic acid oxidase) and promote root development.

[0004] Research shows that the scientific compounding of plant growth regulators and antibacterial agents can significantly enhance the synergistic effect. However, the current research on the compounding of chlorophyllin iron(III) chelate and antibacterial agents for the prevention and control of flue-cured tobacco diseases is still blank. Summary of the Invention

[0005] The present invention provides a compound antibacterial agent for flue-cured tobacco plant growth 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 realizing the goals of green production of flue-cured tobacco and reducing the use of pesticides and fertilizers.

[0006] The object of the present invention can be achieved by the following technical solutions:

[0007] A compound antibacterial agent for flue-cured tobacco plant growth, calculated by weight percentage, comprises the following components:

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

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

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

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

[0012] 。

[0013] Further, in the chemical structural formula of the iron(III) chlorophyllin chelate: R = K; X = OCOCH3.

[0014] Further, the silicone surfactant is the silicone surfactant Silwet L-77.

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

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

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

[0018] The beneficial effects of the present invention:

[0019] (1) Synergistic effect system construction: For the first time, the present invention combines chlorophyllin iron(III) chelate with kasugamycin and dimethomorph for compounding, and realizes disease prevention and control through the dual paths of "immune activation + targeted sterilization". Among them, chlorophyllin iron(III) chelate, as a plant immune inducer, activates the salicylic acid (SA) and jasmonic acid (JA) signaling pathways, enhances the systemic resistance of flue-cured tobacco to Ralstonia solanacearum (bacteria) and Phytophthora parasitica (oomycetes). In the structural formula, the K coordination and OCOCH3 substituent can enhance the liposolubility and promote transmembrane absorption; kasugamycin specifically controls Gram-negative bacteria (such as Ralstonia solanacearum), and blocks protein synthesis by inhibiting the 30S ribosomal subunit; dimethomorph targets the cellulose synthase (CESA3) of oomycetes (such as Phytophthora nicotianae), and inhibits cell wall formation. After detection, the comprehensive control effect of the compound antibacterial agent on bacterial wilt and black shank diseases reaches 80.3% - 94.7%, which is significantly higher than that of the single-agent control group (control effect < 55%), proving the synergistic effect between chlorophyllin iron(III) chelate and the bactericide. At the same time, the yield per mu of tobacco leaves treated with the compound antibacterial agent increases by 18.6% - 26.5%, and the nicotine content is optimized to 2.68% - 3.02%, meeting the high-quality tobacco leaf standard (2.5% - 3.5%). Finally, the present invention breaks through the bottleneck of insufficient control effect of traditional agents on soil-borne diseases through directional sterilization (kasugamycin targets Ralstonia solanacearum, dimethomorph inhibits Phytophthora) combined with systemic resistance induction.

[0020] (2) Directional optimization of surfactants: 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 and high-efficiency formula: The dosage of kasugamycin (0.05% - 0.1%) is significantly lower than the conventional single-agent recommended concentration (0.2% - 0.3%), and the reduction of drug dosage and increase of efficiency are achieved through synergistic effects. Detailed implementation mode

[0022] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative work shall fall within the protection scope of the present invention.

[0023] Example 1

[0024] A compound antibacterial agent for the growth of flue-cured tobacco plants and its preparation method:

[0025] First, by weight percentage, the above compound antibacterial agent comprises the following components: 0.5% of chlorophyll iron(III) chelate, 0.05% of kasugamycin, 0.15% of dimethomorph, 6% of polyglycerol fatty acid ester, 4% of organosilicon surfactant Silwet L-77, 2% of antifreeze ethylene glycol, 10% of methanol, and the balance is pure water. The chemical structural formula of the chlorophyll iron(III) chelate is as follows:

[0026]

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

[0028] Then, the preparation method of the above compound antibacterial agent comprises the following steps: Weigh each raw material by mass percentage, mix the polyglycerol fatty acid ester, organosilicon surfactant Silwet L-77 and methanol, then add the chlorophyll iron(III) chelate, kasugamycin and dimethomorph thereto, and stir and mix at room temperature for 0.1 h to obtain the main agent; then add the antifreeze ethylene glycol to the pure water, and stir and mix at room temperature for 0.1 h to obtain the auxiliary agent; pour the main agent into the auxiliary agent, and stir at room temperature for 0.1 h to obtain the compound antibacterial agent for flue-cured tobacco plant growth.

[0029] Example 2

[0030] A compound antibacterial agent for flue-cured tobacco plant growth and its preparation method:

[0031] First, by weight percentage, the above compound antibacterial agent comprises the following components: 1.0% of chlorophyll iron(III) chelate, 0.08% of kasugamycin, 0.20% of dimethomorph, 7% of polyglycerol fatty acid ester, 4% of organosilicon surfactant Silwet L-77, 3% of antifreeze propylene glycol, 10% of acetone, and the balance is pure water. The chemical structural formula of the chlorophyll iron(III) chelate is as follows:

[0032]

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

[0034] Then, the preparation method of the above compound antibacterial agent comprises the following steps: Weigh each raw material by mass percentage, mix the polyglycerol fatty acid ester, organosilicon surfactant Silwet L-77 and acetone, then add the chlorophyll iron(III) chelate, kasugamycin and dimethomorph thereto, and stir and mix at room temperature for 1 h to obtain the main agent; then add the antifreeze propylene glycol to the pure water, and stir and mix at room temperature for 1 h to obtain the auxiliary agent; pour the main agent into the auxiliary agent, and stir at room temperature for 1 h to obtain the compound antibacterial agent for flue-cured tobacco plant growth.

[0035] Example 3

[0036] Compound antibacterial agent for flue-cured tobacco plant growth and its preparation method:

[0037] First, by weight percentage, the compound antibacterial agent includes the following components: 2.0% chlorophyllin iron(III) chelate, 0.1% kasugamycin, 0.25% dimethomorph, 8% polyglycerol fatty acid ester, 5% organosilicon surfactant Silwet L-77, 4% antifreeze glycerol, 10% cyclohexanone, and the balance is pure water. The chemical structural formula of chlorophyllin iron(III) chelate is shown as follows:

[0038]

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

[0040] Then, the preparation method of the compound antibacterial agent includes the following steps: Weigh each raw material by mass percentage, mix polyglycerol fatty acid ester, organosilicon surfactant Silwet L-77 and cyclohexanone, then add chlorophyllin iron(III) chelate, kasugamycin and dimethomorph to it, stir and mix at room temperature for 2 h to obtain the main agent; then add antifreeze glycerol to pure water, stir and mix at room temperature for 2 h to obtain the auxiliary agent; pour the main agent into the auxiliary agent, and stir at room temperature for 2 h to obtain the compound antibacterial agent for flue-cured tobacco plant growth.

[0041] Comparative Example 1

[0042] Comparative Example 1 is the control group of Example 3. Remove 2.0% chlorophyllin iron(III) chelate and 0.1% kasugamycin in the compound antibacterial agent of Example 3, and keep the dosage of the remaining components unchanged (except pure water), that is, the compound antibacterial agent includes the following components: 0.25% dimethomorph, 8% polyglycerol fatty acid ester, 5% organosilicon surfactant Silwet L-77, 4% antifreeze glycerol, 10% cyclohexanone, and the balance is pure water. At the same time, the preparation method is exactly the same as that in Example 3, and finally, the compound antibacterial agent for flue-cured tobacco plant growth is obtained.

[0043] Comparative Example 2

[0044] Comparative Example 2 is the control group of Example 3. Remove 2.0% chlorophyllin iron(III) chelate and 0.25% dimethomorph in the compound antibacterial agent of Example 3, and keep the dosage of the remaining components unchanged (except pure water), that is, the compound antibacterial agent includes the following components: 0.1% kasugamycin, 8% polyglycerol fatty acid ester, 5% organosilicon surfactant Silwet L-77, 4% antifreeze glycerol, 10% cyclohexanone, and the balance is pure water. At the same time, the preparation method is exactly the same as that in Example 3, and finally, the compound antibacterial agent for flue-cured tobacco plant growth is obtained.

[0045] Comparative Example 3

[0046] Comparative Example 3 is the control group of Example 3. Remove 0.1% kasugamycin and 0.25% dimethomorph in the compound antibacterial agent in Example 3, and keep the dosages of the remaining components unchanged (except pure water). That is, the compound antibacterial agent includes the following components: 2.0% chlorophyllin iron(III) chelate, 8% polyglycerol fatty acid ester, 5% organosilicon surfactant Silwet L-77, 4% antifreeze glycerol, 10% cyclohexanone, and the balance is pure water. At the same time, the preparation method is exactly the same as that in Example 3, and finally a compound antibacterial agent for flue-cured tobacco plant growth is obtained.

[0047] Perform performance tests on the compound 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] I. Test strains: Ralstonia solanacearum (strain YN-2023-01), isolated and identified by the Institute of Plant Protection, Yunnan Academy of Agricultural Sciences; Phytophthora nicotianae (strain KM-2023-02), provided by the Yunnan Academy of Tobacco Sciences.

[0049] II. Test tobacco: Yunyan 87 (main cultivated variety), provided by Yunnan Tobacco Seed Co., Ltd., and transplanted to the experimental field after seedling raising.

[0050] III. Test agents: The compound antibacterial agents for flue-cured tobacco prepared in Examples 1 to 3 and Comparative Examples 1 to 3, among which: chlorophyllin iron(III) chelate is purchased from Nanjing Baite Biotechnology Co., Ltd.; kasugamycin is purchased from Kitakyo Chemical Industry Co., Ltd., Japan; dimethomorph is purchased from Jiangsu Qizhou Green Chemical Co., Ltd.

[0051] IV. Field test process and results:

[0052] (1) Test field setting: The test field is located in the tobacco planting base of Guishan Town, Shilin Yi Autonomous County, Kunming City. The area of a single test field is 50 m 2 , and the soil quality is red soil (pH 5.8, organic matter content 18 g / kg). Before transplanting tobacco, apply 900 kg / hm 2 of special tobacco fertilizer (N:P:K = 10:12:20). The planting row spacing is 120 cm, the plant spacing is 50 cm, and the density is 16,500 plants / hm 2 .

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

[0054] a. Inoculation method: For Ralstonia solanacearum: 30 days after transplanting (vigorous growth period), use the bacterial suspension (1×108 CFU / mL) was used for root irrigation inoculation, 20 mL per plant; Phytophthora parasitica var. nicotianae: 5 days after inoculation, a sporangium suspension (1×10 5 per mL) was sprayed at the base of the stem.

[0055] b. Application plan:

[0056] Experimental group: The compound antibacterial agent was diluted 10,000 times (agent: water = 1:9999), and the first foliar spraying + stem base irrigation (liquid medicine dosage 500 kg / hm 2 ) was carried out 7 days after inoculation, and the second application was carried out at an interval of 15 days; Control group: The same amount of clear water was sprayed; Each group was repeated in 3 experimental fields and arranged in a randomized block design.

[0057] (3) Investigation and calculation:

[0058] Disease assessment: All the plants in the field were investigated 15 days after the last application, and the number of diseased plants was recorded.

[0059] The disease incidence rate of bacterial wilt (%) = (the number of plants with brown wilt at the base of the stem / the total number of plants investigated) × 100%;

[0060] The disease incidence rate of Phytophthora parasitica var. nicotianae (%) = (the number of plants with stem base rot and white mycelia produced / the total number of plants investigated) × 100%;

[0061] The comprehensive control effect (%) = (the disease incidence rate of the control group - the disease incidence rate of the treatment group) / the disease incidence rate of the control group × 100%.

[0062] Yield increase assessment: The yield and quality of tobacco leaves were measured after harvesting.

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

[0064] Nicotine content: The middle tobacco leaves were detected by high performance liquid chromatography (HPLC).

[0065] Table 1 Test results

[0066] Group Rate of plants infected with bacterial wilt (%) Rate of plants infected with black shank (%) Comprehensive control efficacy (%) 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] Analysis:

[0068] 1. Disease prevention and control effect

[0069] (1)Gradient of Examples 1 - 3: With the increase in the concentrations of chlorophyllin 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] Synergy: Chlorophyll iron(III) chelate activates the plant systemic resistance (SA / JA pathway), kasugamycin targets Ralstonia solanacearum (inhibiting protein synthesis), dimethomorph inhibits the cell wall synthesis of Phytophthora, and the triple mechanisms are superimposed.

[0071] Surfactant synergistic effect: A high proportion of polyglycerol fatty acid ester (8%) + Silwet L-77 (5%) improves the permeability of the liquid medicine and enhances the absorption efficiency of the stem base and roots.

[0072] (2) Comparative Example 3 (only chlorophyll iron(III) chelate): The comprehensive control effect is 32.5%, indicating that the immune inducer alone cannot completely kill the pathogenic bacteria and needs to cooperate with the bactericide.

[0073] 2. Yield increase and quality improvement

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

[0075] Nicotine content: The nicotine content in Example 3 reaches 3.02%, which is significantly higher than that of the control group (2.14%) because the expression of nicotine synthesis genes (such as NtPMT) in healthy plants is up-regulated.

[0076] (2) Yield reduction in the comparative example: The yield reduction in Comparative Example 3 (-2.1%) is due to the loss of photosynthetic assimilates caused by severe diseases, verifying the strong correlation between disease prevention and yield increase.

[0077] Conclusion:

[0078] (1) Disease prevention and control: The comprehensive control effect of the compound antibacterial agents in Examples 1-3 on bacterial wilt and black shank reaches 80.3% - 94.7%, which is significantly higher than that of the single-agent control group (control effect < 55%), proving the synergistic effect of chlorophyll iron(III) chelate and the bactericide.

[0079] (2) Yield increase and quality improvement: The yield per mu of tobacco leaves in the treatment group is increased by 18.6% - 26.5%, and the nicotine content is optimized to 2.68% - 3.02% (only 2.14% in the control group), meeting the high-quality tobacco leaf standard (2.5% - 3.5%).

[0080] Note: This experiment complies with the "Guidelines for Field Efficacy Trials of Pesticides" (GB / T 17980.12 - 2022), and the data is analyzed by ANOVA using SPSS 26.0 software (P < 0.01).

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

[0082] Although embodiments of the present invention have been shown and described, those of ordinary skill in the art can understand that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of the present invention. 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: The composition comprises the following components by weight percentage: 1.0% to 2.0% of dihydrochlorin iron (III) chelate, 0.08% to 0.1% of kasugamycin, 0.20% to 0.25% of enoylmorpholine, 7% to 8% of polyglycerol fatty acid ester, 4% to 5% of silicone surfactant, 3% to 4% of antifreeze agent, 10% of organic solvent, and the balance is pure water; The chemical structural formula of the chlorin iron (III) chelate is as follows: ； Said R=K; X=OCOCH3.

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 organosilicon surfactant is the organosilicon surfactant Silwet L-77.

4. 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.

5. 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.

6. A method for preparing a composite antibacterial agent for growing flue-cured tobacco plants according to any one of claims 1 to 5, 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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