Cotton verticillium wilt control agent containing cellulose rare earth compound
By preparing cellulose rare earth compounds RE@ACF and using rare earth chloride and acetylated cellulose to form rare earth-doped biomass composite materials, the problems of insufficient environmental protection and effectiveness of cotton wilt disease were solved, and efficient disease prevention and control effects were achieved.
Patent Information
- Application Number
- CN202510886792.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-06-30
- Publication Date
- 2025-10-10
AI Technical Summary
Existing technologies have problems with environmental friendliness and effectiveness in preventing and controlling cotton wilt. Chemical fungicides have problems with environmental pollution and bacterial resistance, and crop rotation is difficult to implement and has limited effectiveness.
Cellulose rare earth compound RE@ACF was prepared by using rare earth chloride and acetylated cellulose as raw materials, and cellulose was treated with NaOH aqueous solution to form a rare earth-doped biomass rare earth composite material, which can be adsorbed onto the cell wall of Verticillium dahliae through diffusion and electrostatic action, blocking the uptake of nutrients and interfering with its physiological metabolism.
It achieved a highly effective inhibitory effect on Verticillium dahliae, with an inhibition rate of over 99%, and a cure rate of 70% in field experiments, providing an environmentally friendly and effective means of preventing and controlling cotton verticillium wilt.
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Figure CN120753278A_ABST
Abstract
Description
Technical Field
[0001] The invention belongs to the technical field of pesticide preparations, and in particular relates to a cotton Verticillium wilt control agent containing a cellulose rare earth compound. Background Art
[0002] Verticillium wilt, a soil-borne vascular disease of cotton caused by Verticillium dahliae, is one of the most devastating cotton diseases worldwide. It severely impacts cotton yield and quality, and can even lead to plant death. Currently, traditional methods for controlling cotton Verticillium wilt are primarily used internationally, including crop rotation, breeding of disease-resistant varieties, and chemical control. Crop rotation is a crucial practice widely emphasized worldwide to prevent the accumulation of soil-borne pathogens. When the same crop is grown year after year, the development and persistence of soil-borne pathogens is almost certain. Rotating cotton with other crops, such as rice, corn, and wheat, can effectively reduce the disease. However, in practice, crop rotation is difficult to implement due to competition for land between cotton and grain. Furthermore, crop rotation only reduces the number of Verticillium dahliae in the soil to a certain extent and does not eradicate the disease. While chemical fungicides such as azoxystrobin and carbendazim have shown some effectiveness in controlling cotton Verticillium wilt, environmental pollution and the emergence of antibiotic resistance have led to an urgent need for more environmentally friendly and effective control methods.
[0003] Rare earth metals, also known as rare earth elements, are a collective term for 17 elements in Group IIIB of the periodic table, including scandium, yttrium, and lanthanides. Rare earth elements are highly chemically active and, as "industrial monosodium glutamate," have crucial applications in industries such as metallurgy, petrochemicals, glass and ceramics, fluorescence, and electronic materials. They also hold enormous potential for agricultural applications. By the 1980s, rare earth elements were widely used in Chinese agriculture, improving plant mineral nutrition, promoting photosynthesis, and enhancing plant resistance to stress. The rare earth pesticide "Yizhisu" has generated cumulative economic and social benefits totaling 15 billion yuan.
[0004] Rare earth elements can directly inhibit pathogens, reducing their virulence. This study uses chemical methods to combine rare earth elements with acetylated cellulose to prepare a variety of rare earth compounds. Plate standoff assays and other methods are used to screen for antibacterial rare earth materials and concentrations that effectively inhibit the growth of Verticillium dahliae and enhance the antibacterial activity of biocontrol bacteria. Structural characterization techniques are used to elucidate the antibacterial mechanisms of rare earth materials and guide the development of highly effective antibacterial rare earth materials, ultimately leading to the development of rare earth pesticides for the prevention and control of cotton Verticillium wilt. Summary of the Invention
[0005] In view of this, the present invention aims to overcome the defects in the prior art and proposes a cotton Verticillium wilt control agent containing a cellulose rare earth compound.
[0006] To achieve the above object, the technical solution of the present invention is achieved as follows:
[0007] In a first aspect, the present invention provides a cellulose rare earth compound RE@ACF, which is prepared from rare earth chloride and acetylated cellulose as raw materials.
[0008] Preferably, the mass ratio of the rare earth chloride to the acetylated cellulose is 1:(2-5).
[0009] Preferably, the rare earth chloride is lanthanum chloride heptahydrate and / or cerium chloride heptahydrate.
[0010] Preferably, the method for preparing acetylated cellulose comprises the following steps:
[0011] A NaOH aqueous solution is added to the cellulose powder, and the reaction is carried out at a temperature of 60-80°C for 1-2 hours. After the reaction is completed, the pH value is adjusted to 2-4, an acetylation reagent is added, and the temperature is raised to 60-80°C. Heating and stirring are continued for 30-60 minutes, and then the precipitate is collected by centrifugation, dried, and purified to obtain acetylated cellulose.
[0012] Preferably, the acetylating agent is N,N-diisopropylethylamine and acetic anhydride in a mass ratio of 1:(0.7-1.3).
[0013] Preferably, the mass ratio of the cellulose powder to NaOH is 1:(0.2-0.6).
[0014] Preferably, the mass ratio of the cellulose powder to the acetylating agent is 1:(0.5-1.0).
[0015] In a second aspect, the present invention further provides a method for preparing the above-mentioned cellulose rare earth compound RE@ACF, comprising the following steps:
[0016] Rare earth chloride and acetylated cellulose are dissolved in deionized water to obtain a reaction solution, and alkali solution is added dropwise to the reaction solution while stirring, and stirred at room temperature for 2-3 hours. The solution is then filtered, washed with distilled water, and dried to obtain a cellulose rare earth compound RE@ACF.
[0017] Preferably, the alkali solution is one or more of a NaOH aqueous solution, a Na2CO3 aqueous solution, and a NaHCO3 aqueous solution.
[0018] Preferably, the mass concentration of the alkali solution is 0.2-0.3 g / mL.
[0019] Preferably, the mass concentration of the rare earth chloride in the reaction solution is 0.05-0.1 g / mL.
[0020] Preferably, the mass ratio of the rare earth chloride to the added alkali is 1:(0.3-0.5).
[0021] In a third aspect, the present invention also provides the use of a cellulose rare earth compound RE@ACF in the preparation of a biocontrol agent for inhibiting Verticillium dahliae.
[0022] In a fourth aspect, the present invention further provides a cotton Verticillium wilt control agent, wherein the main active ingredient of the cotton Verticillium wilt control agent is a cellulose rare earth compound RE@ACF.
[0023] Compared with the prior art, the present invention has the following advantages:
[0024] (1) The present invention uses a NaOH aqueous solution to pretreat cellulose powder, effectively destroying the crystalline regions of cellulose, increasing the proportion of its amorphous regions, and improving the uniformity and degree of substitution in the subsequent acetylation reaction. Compared to traditional mechanical pulverization or low-temperature alkaline treatment, this method more efficiently opens up the cellulose molecular chains, facilitating the penetration of the acetylation reagent.
[0025] (2) The present invention uses cellulose as a raw material to modify and prepare an acetylated cellulose precursor, which is then loaded with rare earth metal ions to form a rare earth-doped biomass-rare earth composite material. The rare earth metal ions can be adsorbed onto the cell wall of Verticillium dahliae through diffusion and electrostatic interactions, which isolates the fungus from the external environment, blocks nutrient uptake, and interferes with its physiological metabolism.
[0026] (3) In the acetylated cellulose preparation process, the present invention uses N,N-diisopropylethylamine and acetic anhydride as acetylation reagents, replacing traditional strong acids (such as concentrated sulfuric acid) or toxic catalysts (such as pyridine). N,N-diisopropylethylamine, as a weakly alkaline catalyst, neutralizes the acetic acid produced by the reaction, shifting the reaction equilibrium toward the product, while reducing side reactions and improving product purity and reaction safety.
[0027] (4) The present invention is the first to apply rare earth compounds to the prevention and treatment of cotton Verticillium wilt, providing a new technical means for cotton disease prevention and treatment. In addition, the present invention also discloses a simple and easy preparation method, which is conducive to popularization and application. BRIEF DESCRIPTION OF THE DRAWINGS
[0028] Figure 1 This is a statistical bar chart of the inhibition rate of the rare earth control agent LaACF against Verticillium dahliae. DETAILED DESCRIPTION
[0029] The embodiments of the present invention are described in detail below. The embodiments described below are exemplary and are only used to explain the present invention, and should not be understood as limiting the present invention.
[0030] Unless defined otherwise herein, 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.
[0031] Where values are described herein as ranges, it should be understood that such disclosure includes disclosure of all possible sub-ranges within that range, as well as specific values falling within that range, regardless of whether a specific value or sub-range is explicitly stated.
[0032] In this document, "a plurality of" and the like, unless otherwise specified, refer to a number greater than or equal to 2. For example, "one or more" means one or more than or equal to two.
[0033] In this document, the terms “preferably” and “more preferably” are only used to describe implementation methods or examples with better effects. It should be understood that they do not limit the scope of protection of the present invention.
[0034] In this document, the word "further" and the like are used for descriptive purposes to indicate differences in content, but should not be construed as limiting the scope of protection of the present invention.
[0035] In this article, the term "and / or" is used to describe the association relationship between objects, indicating that three relationships can exist. For example, A and / or B means: A or B, or A and B.
[0036] As used herein, the term "about" means + / - 10%, preferably + / - 5%, more preferably + / - 1% of the specified value.
[0037] In this document, the terms “include,” “including,” “have,” “contain,” etc. are open-ended terms, meaning 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 the invention pertains. Although preferred methods and materials have been described herein, any methods and materials similar or equivalent to those described herein can also be used in the practice or testing of the present invention.
[0039] The present invention will be described in detail below with reference to the embodiments.
[0040] Cellulose, sodium bicarbonate, sodium hydroxide, sodium carbonate, hydrochloric acid, N,N-diisopropylethylamine, acetic anhydride, tetrahydrofuran, ethyl acetate, and ethanol were purchased from Aladdin Chemical Co., Ltd.
[0041] Lanthanum chloride heptahydrate and cerium chloride heptahydrate were purchased from Shandong Desheng New Materials Co., Ltd.
[0042] All chemicals were used without further treatment, and deionized water was prepared in the laboratory.
[0043] Verticillium dahliae is a strain screened from cotton plants and soil in the laboratory.
[0044] Unless otherwise specified, all the reagents used are conventional biochemical reagents; the experimental methods described are conventional methods unless otherwise specified.
[0045] The present invention will be described in detail below with reference to the accompanying drawings and in conjunction with embodiments.
[0046] Example 1
[0047] A method for preparing a cotton verticillium wilt control agent containing rare earth lanthanum comprises the following steps:
[0048] (1) Preparation of acetylated cellulose
[0049] Weigh 50g of cellulose powder into a three-necked flask, add 200mL of a 0.1g / mL NaOH aqueous solution, then set the heating temperature to 65°C and continue stirring at this temperature for 1h. After the reaction is completed, adjust the pH to 3 with 1M HCl solution, add 30g of acetylating agent (N,N-diisopropylethylamine and acetic anhydride in a mass ratio of 1:1), then heat to 80°C, continue heating and stirring for 30min, then centrifuge (10000rpm / 10min) to separate, collect the precipitate, and dry at 60°C. The dried product is dissolved in tetrahydrofuran and allowed to stand for 24h. Then, a certain amount of ethyl acetate and deionized water are added to the tetrahydrofuran solution, shaken thoroughly to wash away impurities carried in the product, and then the organic phase is collected and extracted with deionized water three times. The separated organic phase solution is removed by a rotary evaporator at 45°C to obtain acetylated cellulose.
[0050] (2) Preparation of cellulose rare earth compound La@ACF
[0051] Prepare a 0.2g / mL NaHCO3 solution and pour 15mL into a constant-drop funnel. Weigh 10g of lanthanum chloride heptahydrate and 20g of acetylated cellulose into 100mL of deionized water. Hold the constant-drop funnel containing the NaHCO3 solution above the reactor and add the solution dropwise to the reaction mixture while stirring. Stir at room temperature for 2-3 hours. After filtration and washing with distilled water, dry in an oven at 60°C to obtain the final product, La@ACF.
[0052] Example 2
[0053] The difference from Example 1 is that:
[0054] During the preparation of acetylated cellulose, the amount of acetylating agent added was 25 g, and the mass ratio of N,N-diisopropylethylamine to acetic anhydride was 1:0.7.
[0055] The alkali solution used in the preparation process of the cellulose rare earth compound is 25 mL of a Na2CO3 solution with a mass concentration of 0.2 g / mL, and the cellulose rare earth compound La@ACF(a) is obtained.
[0056] Example 3
[0057] The difference from Example 1 is that:
[0058] The mass ratio of N,N-diisopropylethylamine to acetic anhydride in the preparation process of acetylated cellulose is 1:1.3.
[0059] The alkali solution used in the preparation process of the cellulose rare earth compound is 17 mL of NaOH solution with a mass concentration of 0.2 g / mL, and the cellulose rare earth compound La@ACF (b) is obtained.
[0060] Example 4
[0061] The difference from Example 1 is that the alkali solution used in the preparation process of the cellulose rare earth compound is 14 mL of NaHCO3 solution with a mass concentration of 0.3 g / mL, and the cellulose rare earth compound La@ACF(c) is obtained.
[0062] Example 5
[0063] The difference from Example 1 is that:
[0064] The rare earth chloride used in the preparation of the cellulose rare earth compound was 10g of cerium chloride heptahydrate, resulting in the cellulose rare earth compound Ce@ACF. 10g of cerium chloride heptahydrate and 20g of acetylated cellulose were weighed and added to 200mL of deionized water.
[0065] Example 6
[0066] The difference from Example 1 is that during the preparation of acetylated cellulose, the mass concentration of the NaOH aqueous solution is 0.15 g / mL, and La@ACF(d) is obtained.
[0067] Example 7
[0068] The difference from Example 1 is that the amount of acetylating agent added during the preparation of acetylated cellulose is 50 g, and La@ACF(e) is obtained.
[0069] Example 8
[0070] The difference from Example 1 is that the amount of acetylated cellulose added during the preparation of the cellulose rare earth compound is 50 g, and La@ACF(f) is obtained.
[0071] Example 9
[0072] The difference from Example 1 is that the volume of the NaOH aqueous solution in the preparation process of acetylated cellulose is 100 mL, and the cellulose rare earth compound La@ACF (g) is obtained.
[0073] Comparative Example 1
[0074] The difference from Example 1 is that the raw material used in the preparation of the cellulose rare earth compound is unmodified ordinary cellulose, and La@CF is obtained.
[0075] Comparative Example 2
[0076] The difference from Example 1 is that the rare earth raw material used in the preparation of the cellulose rare earth compound is gadolinium chloride heptahydrate, and Gd@ACF is obtained.
[0077] Comparative Example 3
[0078] The difference from Example 1 is that during the preparation of acetylated cellulose, the mass concentration of the NaOH aqueous solution is 0.03 g / mL, and La@ACF(h) is obtained.
[0079] Comparative Example 4
[0080] The difference from Example 1 is that during the preparation of acetylated cellulose, the mass concentration of the NaOH aqueous solution is 0.4 g / mL, and La@ACF(i) is obtained.
[0081] Comparative Example 5
[0082] The difference from Example 1 is that the amount of acetylating agent added during the preparation of acetylated cellulose is 10 g, and La@ACF(j) is obtained.
[0083] Comparative Example 6
[0084] The difference from Example 1 is that the amount of acetylating agent added during the preparation of acetylated cellulose is 120 g, and La@ACF(k) is obtained.
[0085] Comparative Example 7
[0086] The difference from Example 1 is that during the preparation of acetylated cellulose, only 15 g of acetic anhydride was added as the acetylation agent to obtain La@ACF(l).
[0087] Comparative Example 8
[0088] The difference from Example 1 is that during the preparation of the cellulose rare earth compound, the amount of acetylated cellulose added is 5 g, and La@ACF(m) is obtained.
[0089] Comparative Example 9
[0090] The difference from Example 1 is that during the preparation of the cellulose rare earth compound, the amount of acetylated cellulose added is 70 g, and La@ACF(n) is obtained.
[0091] Comparative Example 10
[0092] The difference from Example 1 is that during the preparation of the cellulose rare earth compound, 10 mL of a NaHCO 3 solution with a mass concentration of 0.2 g / mL was weighed and poured into a constant drop funnel to finally obtain La@ACF(o).
[0093] Comparative Example 11
[0094] The difference from Example 1 is that during the preparation of the cellulose rare earth compound, 35 mL of a NaHCO 3 solution with a mass concentration of 0.2 g / mL was weighed and poured into a constant drop funnel to finally obtain La@ACF(p).
[0095] Test Example 1: Antibacterial experiment on Verticillium dahliae plate
[0096] The rare earth control agent was sterilized by ultraviolet and then prepared into a 100 mg / L solution. A 5 mm diameter Verticillium dahliae V991 bacterial block was placed in the center of a potato solid culture medium (PDA) plate, and 5 μL of the rare earth compound solution was dripped 1.5 cm away from the center point. At the same time, a fungal PDA plate with sterile water was used as a blank control for a control experiment. Each treatment was repeated 5 times and cultured in a dark environment at 25°C for 5 days. The radius of the fungal colony was measured, and the inhibition rate was calculated according to the formula. Inhibition rate (%) = (Rr) / R×100%, R is the fungal colony radius of the blank control (cm), r is the fungal colony radius of the treatment group (cm), and the inhibition rate results are as follows: Figure 1 shown.
[0097] according to Figure 1 The inhibition rate statistics calculated based on the inhibition zone radius show that La@ACF has the best control effect on Verticillium dahliae. If the rare earth element lanthanum is replaced by cerium, the control effect will decrease slightly. The control agent prepared with gadolinium can only achieve an effect of 36.7% on Verticillium dahliae, which is poor.
[0098] This invention uses cellulose as a raw material to modify and prepare an acetylated cellulose precursor. Rare earth metal ions are then loaded onto the La@ACF biomass composite material, creating a rare earth-doped biomass composite. This composite material can be adsorbed onto the cell walls of Verticillium dahliae through diffusion and electrostatic interactions. This isolates the fungus from the external environment, blocks nutrient uptake, and interferes with its physiological metabolism. At a concentration of 100 mg / L, the La@ACF exhibits an antibacterial effect of over 99% against the fungus.
[0099] Test Example 2 Field Experiment
[0100] According to the antibacterial results of L. theobromae, materials with an antibacterial rate of more than 90% are selected to carry out field experiments. The field experiment is carried out in the cotton area of Aksu, Xinjiang, from June to August. La@ACF, Ce@ACF, La@ACF(d), La@ACF(e), La@ACF(f), La@ACF(g) are diluted by 1000 times, and then applied to the roots of the diseased cotton. A control group without any treatment is set. The experiment takes the planting area (per mu) as the experimental unit, and each mu is irrigated with 2 tons of diluted pesticide. Each group of experiments sets three parallel groups, and after 2 months of application, the external observation, boll shedding amount and average cotton yield of cotton are counted to determine the cure effect of the pesticide on the cotton Verticillium wilt. The results are shown in Table 1.
[0101] Table 1 Cure rate of cotton plants after treatment with different materials in field experiments
[0102]
[0103]
[0104] From the results of the field experiment, it can be seen that the cure rate of the untreated group is only 10%, while all the treatment groups show certain inhibition effect, which confirms the practical application value of the high antibacterial rate materials selected in the laboratory in the field. The cure rate of La@ACF is 10%-30% higher than that of other treatment groups, which is speculated to be due to the combination of acetylated cellulose and rare earth materials, which can enhance the targeted inhibition ability of Verticillium wilt. The effects of the other materials are weaker. This experiment verifies the practical application potential of the high antibacterial rate materials selected in the laboratory in the field, provides a scientific basis for the green prevention and control of Verticillium wilt in Xinjiang cotton area, and points out the direction for the field optimization of antibacterial materials.
[0105] The present application uses cellulose as raw material to prepare acetylated cellulose precursor, and forms a rare earth doped biomass rare earth composite material La@ACF by loading rare earth metal ions. It can be adsorbed on the cell wall of L. theobromae through diffusion and electrostatic action, which induces L. theobromae to isolate from the external environment, blocks the uptake of nutrients, and interferes with its physiological metabolism. The antibacterial effect of the material on L. theobromae can reach more than 99% at a concentration of 100 mg / L, and the cure rate of cotton plant Verticillium wilt in field experiments can reach 70%.
[0106] The above only describes the preferred embodiments of the present application and is not intended to limit the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the present application shall be included in the protection scope of the present application.
Claims
1. A cellulose rare earth compound RE@ACF, characterized by: The cellulose rare earth compound RE@ACF is prepared from rare earth chloride and acetylated cellulose as raw materials.
2. The cellulose rare earth compound RE@ACF according to claim 1, characterized in that: The mass ratio of the rare earth chloride to the acetylated cellulose is 1:(2-5).
3. The cellulose rare earth compound RE@ACF according to claim 1, characterized in that: The rare earth chloride is lanthanum chloride heptahydrate and / or cerium chloride heptahydrate.
4. The cellulose rare earth compound RE@ACF according to claim 1, characterized in that: The preparation method of the acetylated cellulose comprises the following steps: Adding NaOH aqueous solution to cellulose powder, reacting at 60-80°C for 1-2 hours, adjusting the pH to 2-4, adding acetylation reagent, heating to 60-80°C, continuing heating and stirring for 30-60 minutes, then centrifuging and collecting the precipitate, drying, and purifying to obtain acetylated cellulose; Preferably, the acetylating agent is N,N-diisopropylethylamine and acetic anhydride in a mass ratio of 1:(0.7-1.3). Preferably, the mass ratio of the cellulose powder to NaOH is 1:(0.2-0.6). Preferably, the mass ratio of the cellulose powder to the acetylating agent is 1:(0.5-1.0).
5. The method for preparing the cellulose rare earth compound RE@ACF according to any one of claims 1 to 4, characterized in that: The steps include: Rare earth chloride and acetylated cellulose are dissolved in deionized water to obtain a reaction solution, and alkali solution is added dropwise to the reaction solution while stirring, and stirred at room temperature for 2-3 hours. The solution is then filtered, washed with distilled water, and dried to obtain a cellulose rare earth compound RE@ACF.
6. The method for preparing the cellulose rare earth compound RE@ACF according to claim 5, characterized in that: The alkali solution is one or more of a NaOH aqueous solution, a Na2CO3 aqueous solution, and a NaHCO3 aqueous solution; preferably, the mass concentration of the alkali solution is 0.2-0.3 g / mL.
7. The method for preparing the cellulose rare earth compound RE@ACF according to claim 5, characterized in that: The mass concentration of the rare earth chloride in the reaction solution is 0.05-0.1 g / mL.
8. The method for preparing the cellulose rare earth compound RE@ACF according to claim 5, characterized in that: The mass ratio of the rare earth chloride to the dropwise added alkali is 1:(0.3-0.5).
9. Use of the cellulose rare earth compound RE@ACF according to any one of claims 1 to 4 in the preparation of a biocontrol agent for inhibiting Verticillium dahliae.
10. A cotton Verticillium wilt control agent, characterized in that: The main active ingredient in the cotton verticillium wilt control agent is the cellulose rare earth compound RE@ACF.