Rare earth complex and application thereof in biological control of cotton verticillium wilt
The preparation of rare earth complexes has solved the problems of environmental pollution and drug resistance in the control of cotton Verticillium wilt using traditional chemical control methods, achieving efficient, safe, and environmentally friendly biological control, promoting crop growth and increasing yield.
Patent Information
- Application Number
- CN202510886914.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-06-30
- Publication Date
- 2025-11-07
AI Technical Summary
Traditional chemical control methods for controlling cotton Verticillium wilt present problems such as environmental pollution and pathogen resistance, making it difficult to effectively control the occurrence and development of the disease.
Rare earth complexes are used to prepare a biocontrol agent for cotton Verticillium wilt by reacting catechin polyphenols with rare earth chloride salts and 5-sulfonyl salicylic acid under heating conditions to inhibit the growth and reproduction of pathogens.
Rare earth complexes significantly enhance the fungicidal activity against cotton Verticillium wilt, promote crop growth, increase yield and quality, are environmentally friendly and safe, do not pollute soil and water sources, and are inexpensive.
Smart Images
Figure CN120904145A_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The application belongs to the field of crop disease prevention and treatment, and particularly relates to a rare earth complex and application of the rare earth complex in biological prevention and treatment of cotton Verticillium wilt. BACKGROUND
[0002] With the continuous development of global agriculture, crop disease problems are increasingly prominent, especially for important economic crops such as cotton, the occurrence of diseases not only seriously affects yield and quality, but also causes great losses to farmers' income. Cotton Verticillium wilt, caused by Verticillium dahliae and Verticillium alboatra, is a soil-borne fungal disease, which has the characteristics of rapid transmission, serious damage and difficulty in eradication, and has become one of the main obstacles to cotton production. Although the traditional chemical control method can control the occurrence of diseases to a certain extent, long-term use of chemical pesticides not only leads to environmental pollution, but also may cause drug resistance of the pathogenic bacteria, further aggravating the difficulty of disease control. Therefore, developing new, efficient and environmentally friendly biological control methods has become an important task in the field of agricultural scientific research.
[0003] Rare earth elements, as a special class of chemical elements, have unique physical and chemical properties and biological effects. In recent years, with the in-depth study of rare earth elements, their application potential in the field of agriculture has been gradually tapped. It has been widely recognized that rare earth elements can promote plant growth, enhance plant stress resistance and increase crop yield. Especially in biological control, rare earth elements and their complexes show good antibacterial and antiviral activity, providing a new idea for the development of new biological pesticides. SUMMARY
[0004] Therefore, the application aims to overcome the defects in the prior art and provides a rare earth complex and application of the rare earth complex in biological prevention and treatment of cotton Verticillium wilt.
[0005] To achieve the above-mentioned purpose, the technical scheme of the application is as follows:
[0006] In a first aspect, the application provides a rare earth complex, which comprises the following components in mass fraction:
[0007] catechin polyphenol compound 1-5 parts;
[0008] chlorinated rare earth salt 15-25 parts;
[0009] 5-sulfonyl salicylic acid 12-18 parts;
[0010] water 25-60 parts.
[0011] Preferably, the chlorinated rare earth salt is one or more of LaCl3·7H2O, CeCl3·6H2O, YCl3·6H2O, GdCl3·6H2O or SmCl3·6H2O. More preferably, it is LaCl3·7H2O.
[0012] Preferably, the catechin polyphenol compound comprises one or more of catechin (EC), epicatechin gallate (EGC) and gallocatechin (GC). More preferably, it is catechin.
[0013] The present application is based on the mechanism simulation research that under the heating condition, the carboxyl group at the end of the 5-sulfonyl salicylic acid molecule condenses with the hydroxyl group of the catechin polyphenol compound to form an amide bond, generating an organic intermediate. Since the intermediate has poor chemical stability and is prone to reversible decomposition, a rare earth ion is introduced as a stabilizer in the reaction system. The rare earth ion can form a coordination bond with the intermediate, thereby inhibiting the reverse decomposition of the intermediate structure and promoting the reaction to proceed in the direction of generating a stable rare earth complex. The reaction mechanism (taking lanthanum ion as an example) is as follows:
[0014]
[0015] In a second aspect, the present application provides a preparation method of the above-mentioned rare earth complex, comprising the following steps:
[0016] The catechin polyphenol compound and the chlorinated rare earth salt are mixed in water and stirred to dissolve, 5-sulfonyl salicylic acid is added thereto, and stirring is performed under heating. After the reaction is completed, the mixture is cooled to room temperature to obtain a mixed liquid. The mixed liquid is extracted, washed and dried to obtain the rare earth complex.
[0017] Preferably, the temperature of the heating is 50-90℃, and the stirring time is 2.5-8.5 hours.
[0018] Preferably, the temperature of the drying is 60-90℃, and the drying time is 1-4 hours.
[0019] In a third aspect, the present application further provides the use of the above-mentioned rare earth complex in the preparation of a biocontrol agent for inhibiting P. lateralis.
[0020] In a fourth aspect, the present application provides the use of the above-mentioned rare earth complex in the preparation of a cotton Verticillium wilt biocontrol agent.
[0021] Preferably, the cotton Verticillium wilt biocontrol agent is prepared by ball milling the rare earth complex with water.
[0022] Preferably, the ratio of the rare earth complex to water is (0.5-3) g:(200-800) g, the rotation speed of the ball milling is 200-300 rpm, and the ball milling time is 1-4 hours.
[0023] Preferably, the cotton Verticillium wilt biological control agent is sprayed on the roots of the plants during the cotton seedling stage.
[0024] Preferably, the spraying period is once every 3-8 days, and the spraying is continuously performed for 1-5 times.
[0025] Compared with the prior art, the present application has the following advantages:
[0026] The rare earth complex of the present application exhibits significantly high fungicidal activity against the plant pathogen Verticillium wilt. The present application utilizes the complex formed by the rare earth element and the specific plant extract or microbial metabolite to inhibit the growth and reproduction of the pathogen, destroy its cell structure, or interfere with its metabolic pathways, thereby achieving the purpose of effectively preventing and treating cotton Verticillium wilt. Compared with traditional chemical pesticides, the rare earth complex provided by the present application has the following significant advantages: first, it can not only prevent and treat diseases, but also promote crop growth, increase yield and quality; second, it is environmentally friendly, as the rare earth complex is easily degradable and will not pollute the soil and water sources; third, it is highly efficient and safe, as the rare earth complex is non-toxic and harmless to humans and animals, and will not pose a threat to human health during use; and fourth, it is low in cost, as the raw materials are easily available and the preparation process is simple, making it suitable for large-scale popularization and application. BRIEF DESCRIPTION OF DRAWINGS
[0027] Figure 1 FIG. 1 is a scanning electron microscope image of the rare earth complex of Example 1;
[0028] Figure 2 FIG. 4 is an anti-L. digitatum coating plate experiment of Example 1 and the control group. DETAILED DESCRIPTION
[0029] Embodiments of the present application are described in detail below. The embodiments described below are exemplary and are intended to explain the present application, but should not be construed as limiting the present application.
[0030] In this text, unless otherwise defined, all technical and scientific terms used herein have the same meaning as understood by those skilled in the art to which the present application belongs.
[0031] In this text, in the case of describing a value as a range, it should be understood that such disclosure includes the disclosure of all possible sub-ranges within the range, and the specific numerical values falling within the range, regardless of whether the specific numerical values or specific sub-ranges are explicitly indicated.
[0032] In this text, in the case of describing a value as a range, it should be understood that such disclosure includes the disclosure of all possible sub-ranges within the range, and the specific numerical values falling within the range, regardless of whether the specific numerical values or specific sub-ranges are explicitly indicated.
[0033] In the present text, the terms "preferably", "more preferably" and the like are used where it is wished to specify one or more options, embodiments or embodiments out of several ones, which are seen as particularly preferred, but it is understood that the application is not limited to said preferred options, embodiments or embodiments.
[0034] In the present text, the terms "further" and the like are used where it is wished to specify one or more options, embodiments or embodiments out of several ones, which are seen as particularly preferred, but it is understood that the application is not limited to said preferred options, embodiments or embodiments.
[0035] In the present text, the term "and / or" is a descriptive term for the association of objects, which means that there can be three relationships. For example, A and / or B means: A or B, or A and B, the three relationships.
[0036] In the present text, the term "about" means + / - 10% of the specified value, preferably + / - 5%, more preferably + / - 1%.
[0037] In the present text, the terms "comprising", "including", "having", "containing" and the like are open-ended terms that are intended to mean "including, but not limited to".
[0038] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. Although methods and materials similar or equivalent to those described herein can be used in the practice or testing of the present application, the preferred methods and materials are described. Unless otherwise stated, the following terms are intended to have the meanings presented here.
[0039] LaCl3·7H2O, CeCl3·6H2O, YCl3·6H2O, GdCl3·6H2O and SmCl3·6H2O were purchased from Shanghai McLean Biotech Co., Ltd., cotton seedlings and the strong pathogenic bacteria V991 were provided by Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, and catechin (EC), epigallocatechin (EGC), gallocatechin (GC) and potato dextrose liquid medium were purchased from Aladdin Reagent (Shanghai) Co., Ltd. All chemicals were used without further treatment, and distilled water (ρ = 18.2 MΩ·cm, 25℃) was obtained from a Millipore milli-Q water purification system. In addition, 10.0 mM, pH = 6.0 MES-NaOH buffer was prepared with distilled water using 10.0 mM MES and NaOH as raw materials.
[0040] The application will be described in detail below with reference to the examples.
[0041] Example 1
[0042] A biological control agent for cotton Verticillium wilt, the preparation method comprising the following steps:
[0043] (1) 18 g of lanthanum chloride heptahydrate was dissolved in 50 g of distilled water, 3 g of catechin was added, and the solution was stirred and dissolved at room temperature, and then 15 g of 5-sulfonyl salicylic acid was added, and stirred at 80°C for 5 hours, and cooled to room temperature to form a gel.
[0044] (2) The gel mixture was placed in a Buchner funnel, and then washed by suction filtration to obtain an intermediate.
[0045] (3) The intermediate was dried in an oven at 80°C for 4 hours to prepare a rare earth complex.
[0046] (4) 3 g of the rare earth complex was added to 500 g of purified water, and ball-milled for 3 hours at a rotation speed of 230 rpm to prepare a cotton Verticillium wilt biological control agent.
[0047] Example 2
[0048] A cotton Verticillium wilt biological control agent was prepared by the following steps:
[0049] (1) 15 g of cerium chloride heptahydrate was dissolved in 25 g of distilled water, 1 g of catechin was added, and the solution was stirred and dissolved at room temperature, and then 12 g of 5-sulfonyl salicylic acid was added, and stirred at 50°C for 8.5 hours, and cooled to room temperature to form a gel.
[0050] (2) The gel mixture was placed in a Buchner funnel, and then washed by suction filtration to obtain an intermediate.
[0051] (3) The intermediate was dried in an oven at 60°C for 4 hours to prepare a rare earth complex.
[0052] (4) 3 g of the rare earth complex was added to 500 g of purified water, and ball-milled for 1 hour at a rotation speed of 300 rpm to prepare a cotton Verticillium wilt biological control agent.
[0053] Example 3
[0054] A cotton Verticillium wilt biological control agent was prepared by the following steps:
[0055] (1) 25 g of gadolinium chloride heptahydrate was dissolved in 60 g of distilled water, 5 g of catechin was added, and the solution was stirred and dissolved at room temperature, and then 18 g of 5-sulfonyl salicylic acid was added, and stirred at 90°C for 2.5 hours, and cooled to room temperature to form a gel.
[0056] (2) The gel mixture was placed in a Buchner funnel, and then washed by suction filtration to obtain an intermediate.
[0057] (3) The intermediate was dried in an oven at 90°C for 1 hour to prepare a rare earth complex.
[0058] (4) 0.5 g of the rare earth complex is added to 200 g of pure water, and ball milling is performed for 4 hours at a rotation speed of 200 rpm to prepare the cotton Verticillium wilt biological control agent.
[0059] Example 4
[0060] A cotton Verticillium wilt biological control agent is prepared by the following steps:
[0061] (1) 20 g of samarium chloride heptahydrate is dissolved in 50 g of distilled water, 3 g of catechin is added, and dissolution is performed at room temperature while stirring, and then 15 g of 5-sulfonyl salicylic acid is added, and stirring is performed at 80°C for 5 hours, and then the mixture is cooled to room temperature to form a gel.
[0062] (2) The gel-like mixture is placed in a Buchner funnel, and then suction filtration and washing are performed to obtain an intermediate.
[0063] (3) The intermediate is dried in an oven at 80°C for 4 hours to prepare a rare earth complex.
[0064] (4) 3 g of the rare earth complex is added to 800 g of pure water, and ball milling is performed for 3 hours at a rotation speed of 230 rpm to prepare the cotton Verticillium wilt biological control agent.
[0065] Example 5
[0066] A cotton Verticillium wilt biological control agent is prepared by the following steps:
[0067] (1) 18 g of yttrium chloride heptahydrate is dissolved in 50 g of distilled water, 3 g of catechin is added, and dissolution is performed at room temperature while stirring, and then 15 g of 5-sulfonyl salicylic acid is added, and stirring is performed at 80°C for 5 hours, and then the mixture is cooled to room temperature to form a gel.
[0068] (2) The gel-like mixture is placed in a Buchner funnel, and then suction filtration and washing are performed to obtain an intermediate.
[0069] (3) The intermediate is dried in an oven at 80°C for 4 hours to prepare a rare earth complex.
[0070] (4) 3 g of the rare earth complex is added to 500 g of pure water, and ball milling is performed for 3 hours at a rotation speed of 230 rpm to prepare the cotton Verticillium wilt biological control agent.
[0071] Example 6
[0072] A cotton Verticillium wilt biological control agent is prepared by the following steps:
[0073] (1) 18 g of lanthanum chloride heptahydrate is dissolved in 50 g of distilled water, 3 g of epigallocatechin is added, and dissolution is performed at room temperature while stirring, and then 15 g of 5-sulfonyl salicylic acid is added, and stirring is performed at 80°C for 5 hours, and then the mixture is cooled to room temperature to form a gel.
[0074] (2) Place the gel-like mixture into a Buchner funnel, then filter and wash to obtain an intermediate.
[0075] (3) The intermediate was dried in an oven at 80°C for 4 hours to obtain the rare earth complex.
[0076] (4) Add 3g of rare earth complex to 500g of pure water and ball mill for 3 hours at a speed of 230rpm to obtain a biological control agent for cotton Verticillium wilt.
[0077] Example 7
[0078] A biological control agent for cotton Verticillium wilt, the preparation method of which includes the following steps:
[0079] (1) Dissolve 18g of lanthanum chloride heptahydrate in 50g of distilled water, add 3g of gallocatechin, stir to dissolve at room temperature, then add 15g of 5-sulfonyl salicylic acid, stir at 80℃ for 5 hours, cool to room temperature to form a gel.
[0080] (2) Place the gel-like mixture into a Buchner funnel, then filter and wash to obtain an intermediate.
[0081] (3) The intermediate was dried in an oven at 80°C for 4 hours to obtain the rare earth complex.
[0082] (4) Add 3g of rare earth complex to 500g of pure water and ball mill for 3 hours at a speed of 230rpm to obtain a biological control agent solution for cotton Verticillium wilt.
[0083] The rare earth complex prepared in Example 1 was subjected to scanning electron microscopy, and the results are as follows: Figure 1 As shown, scanning electron microscopy (Mag 35kx, HFW 3.63μm, WD 6.7627mm) reveals that the rare earth complex ultimately forms a nanorod-like structure with a rough surface and attached small particles. The length of the rod is approximately 500nm and the width is approximately 100nm, demonstrating that the reaction enables the rare earth to form a complex with the intermediate.
[0084] Comparative Example 1
[0085] A biological control agent for cotton Verticillium wilt, the preparation method of which includes the following steps:
[0086] (1) Dissolve 18g of lanthanum chloride heptahydrate in 50g of distilled water, add 3g of catechin, stir to dissolve at room temperature, stir at 80℃ for 5 hours, cool to room temperature to form a gel.
[0087] (2) Place the gel-like mixture into a Buchner funnel, then filter and wash to obtain an intermediate.
[0088] (3) The intermediate is dried in an oven at 80°C for 4 hours to obtain a rare earth complex.
[0089] (4) 3g of the rare earth complex is added to 500g of purified water and ball-milled for 3 hours at a speed of 230 rpm to obtain a biological control agent for cotton Verticillium wilt.
[0090] Comparative Example 2
[0091] A biological control agent for cotton Verticillium wilt is prepared by the following steps:
[0092] (1) 18g of lanthanum chloride heptahydrate is dissolved in 50g of distilled water, stirred and dissolved at room temperature, and then 15g of 5-sulfonyl salicylic acid is added, stirred at 80°C for 5 hours, and cooled to room temperature to form a gel.
[0093] (2) The gel-like mixture is placed in a Buchner funnel and then washed by suction filtration to obtain an intermediate.
[0094] (3) The intermediate is dried in an oven at 80°C for 4 hours to obtain a rare earth complex.
[0095] (4) 3g of the rare earth complex is added to 500g of purified water and ball-milled for 3 hours at a speed of 230 rpm to obtain a biological control agent for cotton Verticillium wilt.
[0096] Comparative Example 3
[0097] A biological control agent for cotton Verticillium wilt is prepared by the following steps:
[0098] (1) 18g of lanthanum chloride heptahydrate is dissolved in 50g of distilled water, 3g of chitosan is added, stirred and dissolved at room temperature, and then 15g of 5-sulfonyl salicylic acid is added, stirred at 80°C for 5 hours, and cooled to room temperature to form a gel.
[0099] (2) The gel-like mixture is placed in a Buchner funnel and then washed by suction filtration to obtain an intermediate.
[0100] (3) The intermediate is dried in an oven at 80°C for 4 hours to obtain a rare earth complex.
[0101] (4) 3g of the rare earth complex is added to 500g of purified water and ball-milled for 3 hours at a speed of 230 rpm to obtain a biological control agent for cotton Verticillium wilt.
[0102] Comparative Example 4
[0103] A biological control agent for cotton Verticillium wilt is prepared by the following steps:
[0104] (1) 3 g of catechin was dissolved in 50 g of distilled water at room temperature, and then 15 g of 5-sulfonyl salicylic acid was added thereto and stirred at 80°C for 5 hours, and then cooled to room temperature to form a gel.
[0105] (2) The gel mixture was put into a Buchner funnel, and then washed by suction filtration to obtain an intermediate.
[0106] (3) The intermediate was dried in an oven at 80°C for 4 hours to prepare a rare earth complex.
[0107] (4) 3 g of the rare earth complex was added to 500 g of purified water, and ball-milled for 3 hours at a rotation speed of 230 rpm to prepare a cotton Verticillium wilt biological control agent.
[0108] Comparative Example 5
[0109] A cotton Verticillium wilt biological control agent, the preparation method thereof comprising the following steps:
[0110] (1) 3 g of catechin was dissolved in 50 g of distilled water at room temperature, and then 15 g of 5-sulfonyl salicylic acid was added thereto and stirred at 80°C for 5 hours, and then cooled to room temperature to form a gel.
[0111] (2) The gel mixture was put into a Buchner funnel, and then washed by suction filtration to obtain an intermediate.
[0112] (3) The intermediate was dried in an oven at 80°C for 4 hours to prepare a rare earth complex.
[0113] (4) 3 g of the rare earth complex was added to 500 g of purified water, and ball-milled for 3 hours at a rotation speed of 230 rpm to prepare a cotton Verticillium wilt biological control agent.
[0114] Comparative Example 6
[0115] A cotton Verticillium wilt biological control agent, the preparation method thereof comprising the following steps:
[0116] (1) 3 g of catechin was dissolved in 50 g of distilled water at room temperature, and then 15 g of 5-sulfonyl salicylic acid was added thereto and stirred at 80°C for 5 hours, and then cooled to room temperature to form a gel.
[0117] (2) The gel mixture was put into a Buchner funnel, and then washed by suction filtration to obtain an intermediate.
[0118] (3) The intermediate was dried in an oven at 80°C for 4 hours to prepare a rare earth complex.
[0119] (4) 3 g of the rare earth complex was added to 500 g of pure water, and ball milling was performed for 3 hours at a rotation speed of 230 rpm to prepare the cotton Verticillium wilt biological control agent.
[0120] Test Example 1
[0121] Strain cultivation: cotton seedlings were placed in a 25°C light incubator, and the light cycle was 16 hours of light and 8 hours of darkness, and the humidity was 60%. The cotton seeds were sterilized with 75% alcohol for 5 min, then washed with distilled water for 3 times, and planted in sterile soil.
[0122] Fungus cultivation: the strong pathogenic bacteria V991 were placed in a potato dextrose liquid medium, and cultured at 25°C for 6 days, and then the concentration was adjusted to 10 7 CFU / mL spore suspension.
[0123] Pathogenic bacteria infection treatment: two cotton seedlings with leaves were taken, and root perfusion was performed to infuse 10 mL of 10 7 CFU / mL spore suspension. After inoculation, they were transferred to a light incubator, and the light cycle was 16 hours of light and 8 hours of darkness, and the humidity was 60%.
[0124] Spraying of the cotton Verticillium wilt biological control agent: during the cotton seedling stage, the cotton Verticillium wilt biological control agent prepared in Example 1 was sprayed on the roots of the plants, and the spraying cycle was once every 7 days, and the spraying was continuously performed for 3 times, and sterile water was sprayed on the same batch of plants as a control group.
[0125] The experimental results are shown in Table 1. By comparing the cotton Verticillium wilt biological control agents prepared by different formulations and process conditions, the key mechanism of the ternary synergistic system of the rare earth complex was determined. It can be seen that the ternary complex system (such as Examples 1-7) taking the rare earth chloride (lanthanum / cerium / gadolinium / samarium / yttrium) heptahydrate as the core, the catechin polyphenol compound as the complexing agent, and the 5-sulfonyl salicylic acid as the structure modifier, exhibits a significant disease resistance effect. Among them, the prevention and control effect of Example 1 (lanthanum complex) is the best, and the incidence rate is only 3.33%, which is reduced by 96.63% compared with the control group (98.33%). The experimental conclusions are as follows: the ternary component synergistic effect is crucial, and the absence of any component (such as the absence of 5-sulfonyl salicylic acid in Comparative Example 1, the use of chitosan instead of catechin in Comparative Example 3, and the absence of rare earth chloride salt in Comparative Example 4) will result in a significant decrease in the prevention and control effect (the incidence rate increases to 20%-35%); the amount of 5-sulfonyl salicylic acid needs to be accurately controlled, and the molar ratio thereof to the rare earth directly affects the crystallinity of the complex (the reduction of the amount in Comparative Example 5 causes the incidence rate to increase to 27%). In summary, the biological control agent forms a stable nano structure through the ternary coordination of the rare earth-catechin polyphenol compound-sulfonyl salicylic acid, thereby achieving high-efficiency inhibition of the cotton Verticillium wilt bacteria, and the lanthanum complex exhibits the best comprehensive performance under the optimal process conditions.
[0126] Table 1. Incidence statistics of the examples and comparative examples.
[0127]
[0128]
[0129] Experimental Example 2
[0130] Verticillium dahliae was inoculated onto PDA agar plates and then placed in a constant temperature incubator at 27℃ for 14 days. After the Verticillium dahliae strain had grown well, plates covered with the pathogenic hyphae of Verticillium dahliae were selected, and 8 mm diameter Verticillium dahliae mycelial blocks were scooped out using a punch or a sterile 1 mL pipette tip. The Verticillium dahliae mycelial blocks were placed in the center of the PDA plate, and a small circular filter paper was placed 1.5 cm away from the center of each mycelial block. 5 μL of the test material solution (0.2% concentration) was added to the filter paper. A negative control group consisting only of Verticillium dahliae mycelial blocks without any added liquid was also set up. Each experiment was performed in triplicate. The plates were incubated in the dark at 27℃ for 17 days. After 17 days, the colony diameter of Verticillium dahliae was measured, and the inhibition rate was calculated using the formula: Inhibition rate = Control group colony diameter - Experimental group colony diameter / Control group colony diameter. The inhibition rate results are shown in Table 2.
[0131] Table 2 Antibacterial rates of the examples and comparative examples
[0132]
[0133]
[0134] like Figure 2 As shown, the blank control group had Verticillium dahliae colonies with a diameter of about 8 cm, but no proliferation of Verticillium dahliae was found in the PDA plate containing rare earth complexes. Therefore, the cotton Verticillium wilt biological control agent of the present invention has a very strong effect against cotton Verticillium wilt.
[0135] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.
Claims
1. A rare earth complex characterized in that: The composition comprises the following components in mass fraction: catechin polyphenol compound 1-5 parts; chlorinated rare earth salt 15-25 parts; 5-sulfonyl salicylic acid 12-18 parts; water 25-60 parts.
2. The rare earth complex according to claim 1, characterized in that: The chlorinated rare earth salt is one or more of LaCl3·7H2O, CeCl3·6H2O, YCl3·6H2O, GdCl3·6H2O or SmCl3·6H2O; more preferably LaCl3·7H2O.
3. The rare earth complex according to claim 1, characterized in that: The catechin polyphenol compound comprises one or more of catechin, epigallocatechin and gallocatechin; more preferably catechin.
4. Process for the preparation of the rare earth complex according to claims 1-3, characterized in that: The method comprises the following steps: The catechin polyphenol compound and the chlorinated rare earth salt are mixed in water and stirred to dissolve, 5-sulfonyl salicylic acid is added thereto, and stirring is performed under heating, and after the reaction is completed, the mixture is cooled to room temperature to obtain a mixed liquid; the mixed liquid is filtered, washed and dried to obtain the rare earth complex.
5. Use of the rare earth complex of claims 1-3 in the preparation of a biocontrol agent for inhibiting L. digitata.
6. Use of the rare earth complex of claims 1-3 in the preparation of a cotton Verticillium wilt biocontrol agent.
7. Use according to claim 6, characterized in that: The cotton Verticillium wilt biocontrol agent is prepared by ball milling the rare earth complex with water.
8. Use according to claim 6, characterized in that: The ratio of the rare earth complex to water is (0.5-3) g:(200-800) g.
9. Use according to claim 6, characterized in that: The rotation speed of the ball mill is 200-300 rpm, and the ball milling time is 1-4 hours.
10. The use according to claim 6, characterized in that: In the cotton seedling stage, the cotton Verticillium wilt biocontrol agent is sprayed on the roots of the plants; preferably, the spraying cycle is once every 3-8 days, and the spraying is continuously performed for 1-5 times.