Choline tobacco root-knot nematode inhibitor and preparation method thereof

Abstract

The invention relates to the technical field of pest repellents, and discloses a choline tobacco root-knot nematode inhibitor and a preparation method thereof. The choline tobacco root-knot nematode inhibitor provided by the invention is prepared from the following raw materials in parts by mass: 10 to 20 parts of choline derivative, 5 to 10 parts of mixed plant essential oil, 3 to 5 parts of compound microbial agent, 1 to 3 parts of sodium alginate, 3 to 5 parts of emulsifier and 40 to 60 parts of water. The choline tobacco root-knot nematode inhibitor provided by the invention has a good inhibition effect on tobacco root-knot nematode, and can effectively block a parasitic channel of the root-knot nematode and restore normal growth of plants; the choline tobacco root-knot nematode inhibitor provided by the invention has relatively high biological safety.

Description

Technical Field

[0001] The present invention relates to the technical field of pest repellents, and more particularly to a choline-based tobacco root-knot nematode inhibitor and a preparation method thereof. Background Art

[0002] Tobacco root-knot nematode disease is one of the important diseases that harm tobacco production. After the root-knot nematode invades the tobacco roots, it will stimulate the proliferation of root cells, forming root knots of different sizes, seriously affecting the absorption of water and nutrients by the tobacco roots, resulting in weak growth of tobacco plants, yellowing of leaves, reduction in yield, and decline in quality. Therefore, the research and development of tobacco root-knot nematode inhibitors is of great significance for tobacco planting. Summary of the Invention

[0003] The purpose of the present invention is to provide a choline-based tobacco root-knot nematode inhibitor and a preparation method thereof. The choline-based tobacco root-knot nematode inhibitor has a good inhibitory effect on tobacco root-knot nematodes and can effectively block the parasitic channels of root-knot nematodes and restore the normal growth of plants.

[0004] To achieve the above object, the present invention provides the following technical solutions: One of the technical solutions of the present invention: A choline-based tobacco root-knot nematode inhibitor, comprising the following raw materials in parts by mass: 10 - 20 parts of choline derivative, 5 - 10 parts of mixed plant essential oil, 3 - 5 parts of compound microbial agent, 1 - 3 parts of sodium alginate, 3 - 5 parts of emulsifier, and 40 - 60 parts of water.

[0005] Further, the structural formula of the choline derivative is: .

[0006] Further, the preparation method of the choline derivative comprises the following steps: First, dissolve choline chloride in dichloromethane to form a choline chloride solution, then add triethylamine to the choline chloride solution to form a mixed solution, and finally dropwise add 4-fluorobenzoyl chloride to the mixed solution. After the dropwise addition is completed, react and purify to obtain the choline derivative.

[0007] Even further, the molar ratio of choline chloride, triethylamine, and 4-fluorobenzoyl chloride is 1:1.2:1.

[0008] Even further, the dropping rate is 30 d / min.

[0009] Even further, the reaction is specifically: react at room temperature for 6 h.

[0010] Further, the purification specifically includes: filtration, washing successively with 5% dilute hydrochloric acid, saturated sodium bicarbonate, and water, and rotary evaporation.

[0011] In the present invention, the synthesis equation of the choline derivative is: 。

[0012] Further, the preparation method of the mixed plant essential oil includes the following steps: 1) Mix peppermint leaves and rosemary branches and leaves, and pulverize to obtain the raw material of the mixed plant essential oil; 2) Place the raw material of the mixed plant essential oil obtained in step 1) in water, perform steam distillation, and separate oil and water to obtain the mixed plant essential oil.

[0013] Further, in step 1), the mass ratio of the peppermint leaves to the rosemary branches and leaves is 1∶(0.4 - 0.6).

[0014] Further, in step 2), the mass - to - volume ratio of the raw material of the mixed plant essential oil to water is 1∶(4 - 6).

[0015] Further, in step 2), the steam distillation specifically is: perform steam distillation at 95 - 105 °C for 2 - 4 h.

[0016] Further, the compound microbial inoculum is composed of Bacillus subtilis and Bacillus amyloliquefaciens mixed in a mass ratio of 1∶1.

[0017] The second technical solution of the present invention: The preparation method of the above - mentioned choline - based tobacco root - knot nematode inhibitor includes the following steps: 1) Add the choline derivative, the compound microbial inoculum, and sodium alginate into water, and stir to obtain a pre - mixed solution; 2) Add the mixed plant essential oil and an emulsifier into the pre - mixed solution obtained in step 1), and stir and emulsify to obtain the choline - based tobacco root - knot nematode inhibitor.

[0018] Further, in step 1), the water needs to be pre - heated to 50 - 60 °C.

[0019] Further, in step 1), the stirring specifically is: maintain the temperature at 50 - 60 °C and stir for 40 - 60 min.

[0020] Further, in step 2), the stirring and emulsifying specifically is: stir and emulsify at 50 - 60 °C for 1 - 2 h.

[0021] Compared with the prior art, the beneficial effects of the present invention are as follows: When a choline-based tobacco root-knot nematode inhibitor provided by the present invention acts directly on the second-stage larvae of tobacco root-knot nematodes, the mortality rate of the second-stage larvae of tobacco root-knot nematodes can reach 76% in 24 hours and 88% in 48 hours. Compared with the commonly used insecticide abamectin, the choline-based tobacco root-knot nematode inhibitor provided by the present invention has a better direct killing effect on tobacco root-knot nematodes; After the choline-based tobacco root-knot nematode inhibitor provided by the present invention is applied by irrigation, the root-knot index can reach 1, the nematode reduction rate can reach 82%, the plant height can reach 117 cm, and the SPAD value can reach 42. This shows that the choline-based tobacco root-knot nematode inhibitor provided by the present invention has a good inhibitory effect on tobacco root-knot nematodes and can effectively block the parasitic channels of root-knot nematodes and restore the normal growth of plants; When the choline-based tobacco root-knot nematode inhibitor provided by the present invention is directly sprayed on the surface of K326 tobacco leaves, there are no symptoms such as leaf burns and deformities, and it has a low contact toxicity to bees. This shows that the choline-based tobacco root-knot nematode inhibitor provided by the present invention has a high biological safety.

[0022] In the choline-based tobacco root-knot nematode inhibitor provided by the present invention, the choline derivative has a targeted neurotoxicity to tobacco root-knot nematodes. Specifically, the choline derivative provided by the present invention can interfere with the synthesis, release and conduction of neurotransmitters such as acetylcholine, and the 4-fluorobenzoic acid released after hydrolysis can interfere with the energy metabolism of tobacco root-knot nematodes, thereby achieving the inhibitory effect on tobacco root-knot nematodes; In the choline-based tobacco root-knot nematode inhibitor provided by the present invention, the odor volatilized by the mixed plant essential oil can repel root-knot nematodes, making the root-knot nematodes away from the tobacco roots and reducing the risk of tobacco being infected by root-knot nematodes; at the same time, the active ingredients contained in the plant essential oil can directly act on root-knot nematodes, interfere with the physiological and biochemical processes of root-knot nematodes, and inhibit their growth and reproduction, thereby reducing the harm of root-knot nematodes to tobacco; In the choline-based tobacco root-knot nematode inhibitor provided by the present invention, the complex microbial inoculant can produce a variety of antibacterial substances during metabolism, such as lipopeptide and protein antibiotics, which have a direct inhibitory effect on root-knot nematodes; in addition, the complex microbial inoculant can also colonize on the surface of tobacco roots to form a protective film to prevent root-knot nematodes from invading and reduce the risk of tobacco being infected by root-knot nematodes; In the choline-based tobacco root-knot nematode inhibitor provided by the present invention, sodium alginate can form a protective film on the surface of tobacco roots to prevent root-knot nematodes from invading and reduce the risk of tobacco being infected by root-knot nematodes; In a choline-based tobacco root-knot nematode inhibitor provided by the present invention, choline derivatives can interfere with the nervous system of root-knot nematodes and inhibit the growth and reproduction of root-knot nematodes; plant essential oils are volatile and biologically active, capable of repelling and inhibiting root-knot nematodes; the compound microbial inoculum can produce a variety of antibacterial substances and has an inhibitory effect on root-knot nematodes; sodium alginate can form a protective film on the tobacco roots to prevent the invasion of root-knot nematodes. The four work synergistically to greatly improve the inhibitory effect on tobacco root-knot nematodes. Detailed Embodiments

[0023] The various exemplary embodiments of the present invention will now be described in detail. This detailed description should not be considered as a limitation of the present invention, but rather as a more detailed description of certain aspects, characteristics, and implementation embodiments of the present invention. It should be understood that the terms used in the present invention are only for describing specific embodiments and are not intended to limit the present invention.

[0024] In addition, for the numerical ranges in the present invention, it should be understood that each intermediate value between the upper and lower limits of the range is also specifically disclosed. Each intermediate value within any stated value or stated range, as well as each smaller range between any other stated value or intermediate value within the stated range, is also included in the present invention. The upper and lower limits of these smaller ranges may be independently included or excluded from the range.

[0025] Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the art to which the present invention pertains. Although the present invention only describes preferred methods and materials, any methods and materials similar or equivalent to those described herein can also be used in the implementation or testing of the present invention. All documents mentioned in this specification are incorporated by reference to disclose and describe the methods and / or materials related to the documents. In case of conflict with any incorporated document, the content of this specification shall prevail.

[0026] Without departing from the scope or spirit of the present invention, various improvements and changes can be made to the specific embodiments of the present invention specification, which are obvious to those skilled in the art. Other embodiments obtained from the specification of the present invention are obvious to those skilled in the art. The specification and embodiments of the present invention are only exemplary.

[0027] Regarding the use of "comprising", "including", "having", "containing", etc. herein, they are all open-ended terms, meaning including but not limited to.

[0028] In the following examples, the Bacillus subtilis was purchased from the China General Microbiological Culture Collection Center, with the preservation number CGMCC.No. 1.9086; the Bacillus amyloliquefaciens was purchased from the China General Microbiological Culture Collection Center, with the preservation number CGMCC.No. 1.3450.

[0029] In the following examples, a preparation method of a choline - type tobacco root - knot nematode inhibitor includes the following steps: 1. Preparation of choline derivative: According to the molar ratio of choline chloride, triethylamine and 4 - fluorobenzoyl chloride being 1∶1.2∶1, first dissolve choline chloride in dichloromethane to form a choline chloride solution. Then add triethylamine to the choline chloride solution to form a mixed solution. Finally, control the dropping rate at 30 d / min, drop 4 - fluorobenzoyl chloride into the mixed solution. After the dropping is completed, react at room temperature for 6 h, filter, and wash successively with 5% dilute hydrochloric acid, saturated sodium bicarbonate, and water, and then perform rotary evaporation to obtain the choline derivative; 2. Preparation of mixed plant essential oil: 1) Mix peppermint leaves and rosemary branches and leaves according to the mass ratio of 1∶(0.4 - 0.6), and crush them into fragments of 0.2 - 0.4 cm to obtain the raw material of mixed plant essential oil; 2) According to the mass - to - volume ratio of the raw material of mixed plant essential oil to water being 1∶(4 - 6), place the raw material of mixed plant essential oil obtained in step 1) in water, and perform steam distillation at 95 - 105 °C for 2 - 4 h, and then perform oil - water separation to obtain the mixed plant essential oil; 3. Preparation of compound microbial inoculum: Mix Bacillus subtilis and Bacillus amyloliquefaciens according to the mass ratio of 1∶1 to obtain the compound microbial inoculum; 4. Preparation of choline - type tobacco root - knot nematode inhibitor: 1) Weigh each raw material according to the following mass parts: 10 - 20 parts of choline derivative, 5 - 10 parts of mixed plant essential oil, 3 - 5 parts of compound microbial inoculum, 1 - 3 parts of sodium alginate, 3 - 5 parts of emulsifier, and 40 - 60 parts of water; 2) Heat the water weighed in step 1) to 50 - 60 °C, then add the choline derivative, compound microbial inoculum, and sodium alginate weighed in step 1) to the heated water, and maintain the temperature at 50 - 60 °C and stir for 40 - 60 min to obtain a pre - mixed solution; 3) Add the mixed plant essential oil and emulsifier weighed in step 1) to the pre - mixed solution obtained in step 2), and stir and emulsify at 50 - 60 °C for 1 - 2 h to obtain the choline - type tobacco root - knot nematode inhibitor.

[0030] Example 1 A choline - type tobacco root - knot nematode inhibitor 1. Preparation of choline derivative: Choline chloride (1.39 g, 10 mmol) was dissolved in dichloromethane to form a choline chloride solution. Then, triethylamine (1.66 mL, 12 mmol) was added to the choline chloride solution to obtain a mixed solution. Finally, with the dropping rate controlled at 30 d / min, 4-fluorobenzoyl chloride (1.19 mL, 10 mmol) was dropped into the mixed solution. After the dropping was completed, the reaction was carried out at room temperature for 6 h. Then, it was filtered and washed successively with 5% dilute hydrochloric acid, saturated sodium bicarbonate, and water, and rotary evaporated to obtain a choline derivative; 2. Preparation of the mixed plant essential oil: 1) According to the mass ratio of peppermint leaves to rosemary branches and leaves of 1:0.4, peppermint leaves and rosemary branches and leaves were mixed and crushed into fragments of 0.2 - 0.4 cm to obtain the raw material of the mixed plant essential oil; 2) According to the mass - to - volume ratio of the raw material of the mixed plant essential oil to water of 1:4, the raw material of the mixed plant essential oil obtained in step 1) was placed in water and steam distilled at 95°C for 2 h, and the oil - water separation was carried out to obtain the mixed plant essential oil; 3. Preparation of the composite microbial inoculum: According to the mass ratio of Bacillus subtilis to Bacillus amyloliquefaciens of 1:1, Bacillus subtilis and Bacillus amyloliquefaciens were mixed to obtain the composite microbial inoculum; 4. Preparation of the choline - based tobacco root - knot nematode inhibitor: 1) Weigh the following raw materials according to the following parts by mass: 10 parts of choline derivative, 5 parts of mixed plant essential oil, 3 parts of composite microbial inoculum, 1 part of sodium alginate, 3 parts of emulsifier, and 40 parts of water; 2) Heat the water weighed in step 1) to 50°C, and then add the choline derivative, composite microbial inoculum, and sodium alginate weighed in step 1) to the heated water, and maintain the temperature at 50°C and stir for 40 min to obtain a pre - mixed solution; 3) Add the mixed plant essential oil and emulsifier weighed in step 1) to the pre - mixed solution obtained in step 2), and stir and emulsify at 50°C for 1 h to obtain the choline - based tobacco root - knot nematode inhibitor.

[0031] Example 2 A choline - based tobacco root - knot nematode inhibitor 1. Preparation of the choline derivative: Choline chloride (1.39 g, 10 mmol) was dissolved in dichloromethane to form a choline chloride solution. Then, triethylamine (1.66 mL, 12 mmol) was added to the choline chloride solution to obtain a mixed solution. Finally, 4-fluorobenzoyl chloride (1.19 mL, 10 mmol) was added dropwise to the mixed solution at a dropping rate of 30 d / min. After the addition was completed, the reaction was carried out at room temperature for 6 h. The mixture was filtered and washed successively with 5% dilute hydrochloric acid, saturated sodium bicarbonate, and water, and then rotary evaporated to obtain a choline derivative; 2. Preparation of mixed plant essential oil: 1) Mix peppermint leaves and rosemary branches and leaves according to a mass ratio of 1:0.5, and crush them into segments of 0.2 - 0.4 cm to obtain the raw material for mixed plant essential oil; 2) Place the raw material for mixed plant essential oil obtained in step 1) in water according to a mass-volume ratio of 1:5, and perform steam distillation at 100 °C for 3 h, then separate the oil and water to obtain the mixed plant essential oil; 3. Preparation of compound microbial inoculum: Mix Bacillus subtilis and Bacillus amyloliquefaciens according to a mass ratio of 1:1 to obtain the compound microbial inoculum; 4. Preparation of choline-based tobacco root-knot nematode inhibitor: 1) Weigh each raw material according to the following parts by mass: 15 parts of choline derivative, 8 parts of mixed plant essential oil, 4 parts of compound microbial inoculum, 2 parts of sodium alginate, 4 parts of emulsifier, and 50 parts of water; 2) Heat the water weighed in step 1) to 55 °C, then add the choline derivative, compound microbial inoculum, and sodium alginate weighed in step 1) to the heated water, and stir at 55 °C for 50 min to obtain a pre-mixed solution; 3) Add the mixed plant essential oil and emulsifier weighed in step 1) to the pre-mixed solution obtained in step 2), and stir and emulsify at 55 °C for 1.5 h to obtain the choline-based tobacco root-knot nematode inhibitor.

[0032] Example 3 A choline-based tobacco root-knot nematode inhibitor 1. Preparation of choline derivative: Dissolve choline chloride (1.39 g, 10 mmol) in dichloromethane to form a choline chloride solution. Then add triethylamine (1.66 mL, 12 mmol) to the choline chloride solution to obtain a mixed solution. Finally, control the dropping rate at 30 d / min and drop 4-fluorobenzoyl chloride (1.19 mL, 10 mmol) into the mixed solution. After the dropping is completed, react at room temperature for 6 h, filter, wash successively with 5% dilute hydrochloric acid, saturated sodium bicarbonate, and water, and perform rotary evaporation to obtain a choline derivative; 2. Preparation of mixed plant essential oil: 1) Mix peppermint leaves and rosemary branches and leaves according to a mass ratio of 1:0.6, and crush them into fragments with a size of 0.2 - 0.4 cm to obtain raw materials for mixed plant essential oil; 2) Place the raw materials for mixed plant essential oil obtained in step 1) in water according to a mass-volume ratio of 1:6, and perform steam distillation at 105°C for 4 h, then separate the oil and water to obtain the mixed plant essential oil; 3. Preparation of compound microbial inoculum: Mix Bacillus subtilis and Bacillus amyloliquefaciens according to a mass ratio of 1:1 to obtain the compound microbial inoculum; 4. Preparation of choline-based tobacco root-knot nematode inhibitor: 1) Weigh each raw material according to the following parts by mass: 20 parts of choline derivative, 10 parts of mixed plant essential oil, 5 parts of compound microbial inoculum, 3 parts of sodium alginate, 5 parts of emulsifier, 60 parts of water; 2) Heat the water weighed in step 1) to 60°C, then add the choline derivative, compound microbial inoculum, and sodium alginate weighed in step 1) to the heated water, maintain the temperature at 60°C and stir for 60 min to obtain a pre-mixed solution; 3) Add the mixed plant essential oil and emulsifier weighed in step 1) to the pre-mixed solution obtained in step 2), and stir and emulsify at 60°C for 2 h to obtain the choline-based tobacco root-knot nematode inhibitor.

[0033] Comparative Example 1 A choline-based tobacco root-knot nematode inhibitor 1. Preparation of mixed plant essential oil: 1) Mix peppermint leaves and rosemary branches and leaves according to a mass ratio of 1:0.5, and crush them into fragments with a size of 0.2 - 0.4 cm to obtain raw materials for mixed plant essential oil; 2) Place the raw materials for mixed plant essential oil obtained in step 1) in water according to a mass-volume ratio of 1:5, and perform steam distillation at 100°C for 3 h, then separate the oil and water to obtain the mixed plant essential oil; 2. Preparation of compound microbial inoculum: Mix Bacillus subtilis and Bacillus amyloliquefaciens according to the mass ratio of 1:1 to obtain the compound microbial inoculum; 3. Preparation of choline-based tobacco root-knot nematode inhibitor: 1) Weigh each raw material according to the following parts by mass: 15 parts of choline chloride, 8 parts of mixed plant essential oils, 4 parts of compound microbial inoculum, 2 parts of sodium alginate, 4 parts of emulsifier, 50 parts of water; 2) Heat the water weighed in step 1) to 55 °C, then add the choline chloride, compound microbial inoculum and sodium alginate weighed in step 1) to the heated water, maintain the temperature at 55 °C and stir for 50 min to obtain a premixed solution; 3) Add the mixed plant essential oils and emulsifier weighed in step 1) to the premixed solution obtained in step 2), stir and emulsify at 55 °C for 1.5 h to obtain the choline-based tobacco root-knot nematode inhibitor.

[0034] Comparative Example 2 A choline-based tobacco root-knot nematode inhibitor 1. Preparation of choline derivative: Dissolve choline chloride (1.39 g, 10 mmol) in dichloromethane to form a choline chloride solution, then add triethylamine (1.66 mL, 12 mmol) to the choline chloride solution to obtain a mixed solution. Finally, control the dropping rate at 30 d / min, drop 4-fluorobenzoyl chloride (1.19 mL, 10 mmol) into the mixed solution. After the dropping is completed, react at room temperature for 6 h, filter, wash successively with 5% dilute hydrochloric acid, saturated sodium bicarbonate, and water, and rotary evaporate to obtain the choline derivative; 2. Preparation of mixed plant essential oils: 1) Mix mint leaves and lavender according to the mass ratio of 1:0.5, crush them into fragments of 0.2 - 0.4 cm to obtain the raw material of mixed plant essential oils; 2) Place the raw material of mixed plant essential oils obtained in step 1) in water according to the mass-volume ratio of 1:5, perform steam distillation at 100 °C for 3 h, and separate the oil and water to obtain the mixed plant essential oils; 3. Preparation of compound microbial inoculum: Mix Bacillus subtilis and Bacillus amyloliquefaciens according to the mass ratio of 1:1 to obtain the compound microbial inoculum; 4. Preparation of choline-based tobacco root-knot nematode inhibitor: 1) Weigh each raw material according to the following parts by mass: 15 parts of choline derivative, 8 parts of mixed plant essential oil, 4 parts of compound microbial inoculum, 2 parts of sodium alginate, 4 parts of emulsifier, 50 parts of water; 2) Heat the water weighed in step 1) to 55 °C, then add the choline derivative, compound microbial inoculum and sodium alginate weighed in step 1) to the heated water, maintain the temperature at 55 °C and stir for 50 min to obtain a premixed solution; 3) Add the mixed plant essential oil and emulsifier weighed in step 1) to the premixed solution obtained in step 2), stir and emulsify at 55 °C for 1.5 h to obtain the choline-based tobacco root-knot nematode inhibitor.

[0035] Comparative Example 3 A choline-based tobacco root-knot nematode inhibitor 1. Preparation of choline derivative: Dissolve choline chloride (1.39 g, 10 mmol) in dichloromethane to form a choline chloride solution, then add triethylamine (1.66 mL, 12 mmol) to the choline chloride solution to obtain a mixed solution. Finally, control the dropping rate at 30 drops / min, dropwise add 4-fluorobenzoyl chloride (1.19 mL, 10 mmol) to the mixed solution. After the dropping is completed, react at room temperature for 6 h, filter, wash successively with 5% dilute hydrochloric acid, saturated sodium bicarbonate and water, and rotary evaporate to obtain the choline derivative; 2. Preparation of mixed plant essential oil: 1) Mix lavender and rosemary branches and leaves according to the mass ratio of 1:0.5, crush them into fragments of 0.2 - 0.4 cm to obtain the raw material of mixed plant essential oil; 2) Place the raw material of mixed plant essential oil obtained in step 1) in water according to the mass-volume ratio of 1:5, carry out steam distillation at 100 °C for 3 h, and separate the oil and water to obtain the mixed plant essential oil; 3. Preparation of compound microbial inoculum: Mix Bacillus subtilis and Bacillus amyloliquefaciens according to the mass ratio of 1:1 to obtain the compound microbial inoculum; 4. Preparation of choline-based tobacco root-knot nematode inhibitor: 1) Weigh each raw material according to the following mass parts: 15 parts of choline derivative, 8 parts of mixed plant essential oil, 4 parts of compound microbial inoculum, 2 parts of sodium alginate, 4 parts of emulsifier, 50 parts of water; 2) Heat the water weighed in step 1) to 55 °C, then add the choline derivative, compound microbial inoculum and sodium alginate weighed in step 1) to the heated water, maintain the temperature at 55 °C and stir for 50 min to obtain a premixed solution; 3) Add the mixed plant essential oil and emulsifier weighed in step 1) to the pre-mixed solution obtained in step 2), and stir and emulsify at 55 °C for 1.5 h to obtain the choline-based tobacco root-knot nematode inhibitor.

[0036] Comparative Example 4 A choline-based tobacco root-knot nematode inhibitor 1. Preparation of choline derivative: Dissolve choline chloride (1.39 g, 10 mmol) in dichloromethane to form a choline chloride solution. Then add triethylamine (1.66 mL, 12 mmol) to the choline chloride solution to obtain a mixed solution. Finally, control the dropping rate at 30 d / min, and drop 4-fluorobenzoyl chloride (1.19 mL, 10 mmol) into the mixed solution. After the dropping is completed, react at room temperature for 6 h, filter, wash successively with 5% dilute hydrochloric acid, saturated sodium bicarbonate, and water, and rotary evaporate to obtain the choline derivative; 2. Preparation of mixed plant essential oil: 1) Mix peppermint leaves and rosemary branches and leaves according to the mass ratio of 1:0.5, and crush them into fragments of 0.2 - 0.4 cm to obtain the raw material of mixed plant essential oil; 2) Place the raw material of mixed plant essential oil obtained in step 1) in water according to the mass-volume ratio of the raw material of mixed plant essential oil to water of 1:5, and perform steam distillation at 100 °C for 3 h, and separate the oil and water to obtain the mixed plant essential oil; 3. Preparation of choline-based tobacco root-knot nematode inhibitor: 1) Weigh each raw material according to the following parts by mass: 15 parts of choline derivative, 8 parts of mixed plant essential oil, 4 parts of Bacillus subtilis, 2 parts of sodium alginate, 4 parts of emulsifier, 50 parts of water; 2) Heat the water weighed in step 1) to 55 °C, then add the choline derivative, Bacillus subtilis, and sodium alginate weighed in step 1) to the heated water, and stir at 55 °C for 50 min to obtain a pre-mixed solution; 3) Add the mixed plant essential oil and emulsifier weighed in step 1) to the pre-mixed solution obtained in step 2), and stir and emulsify at 55 °C for 1.5 h to obtain the choline-based tobacco root-knot nematode inhibitor.

[0037] Comparative Example 5 A choline-based tobacco root-knot nematode inhibitor 1. Preparation of choline derivative: Choline chloride (1.39 g, 10 mmol) was dissolved in dichloromethane to form a choline chloride solution. Then, triethylamine (1.66 mL, 12 mmol) was added to the choline chloride solution to obtain a mixed solution. Finally, 4-fluorobenzoyl chloride (1.19 mL, 10 mmol) was added dropwise to the mixed solution at a dropping rate of 30 d / min. After the addition was completed, the reaction was carried out at room temperature for 6 h. The mixture was filtered and washed successively with 5% dilute hydrochloric acid, saturated sodium bicarbonate, and water, and then rotary evaporated to obtain the choline derivative; 2. Preparation of mixed plant essential oil: 1) According to the mass ratio of mint leaves to rosemary branches and leaves of 1:0.5, mint leaves and rosemary branches and leaves were mixed and crushed into fragments of 0.2 - 0.4 cm to obtain the raw material for mixed plant essential oil; 2) According to the mass-volume ratio of the raw material for mixed plant essential oil to water of 1:5, the raw material for mixed plant essential oil obtained in step 1) was placed in water and steam distilled at 100 °C for 3 h. The oil and water were separated to obtain the mixed plant essential oil; 3. Preparation of choline-based tobacco root-knot nematode inhibitor: 1) Weigh the following raw materials according to the following parts by mass: 15 parts of choline derivative, 8 parts of mixed plant essential oil, 4 parts of Bacillus amyloliquefaciens, 2 parts of sodium alginate, 4 parts of emulsifier, 50 parts of water; 2) Heat the water weighed in step 1) to 55 °C, and then add the choline derivative, Bacillus amyloliquefaciens, and sodium alginate weighed in step 1) to the heated water. Maintain the temperature at 55 °C and stir for 50 min to obtain a pre-mixed solution; 3) Add the mixed plant essential oil and emulsifier weighed in step 1) to the pre-mixed solution obtained in step 2), and stir and emulsify at 55 °C for 1.5 h to obtain the choline-based tobacco root-knot nematode inhibitor.

[0038] Comparative Example 6 A choline-based tobacco root-knot nematode inhibitor 1. Preparation of choline derivative: Choline chloride (1.39 g, 10 mmol) was dissolved in dichloromethane to form a choline chloride solution. Then, triethylamine (1.66 mL, 12 mmol) was added to the choline chloride solution to obtain a mixed solution. Finally, 4-fluorobenzoyl chloride (1.19 mL, 10 mmol) was added dropwise to the mixed solution at a dropping rate of 30 d / min. After the addition was completed, the reaction was carried out at room temperature for 6 h. The mixture was filtered and washed successively with 5% dilute hydrochloric acid, saturated sodium bicarbonate, and water, and then rotary evaporated to obtain the choline derivative; 2. Preparation of mixed plant essential oil: 1) Mix peppermint leaves and rosemary branches and leaves according to the mass ratio of 1:0.5, crush them into fragments of 0.2 - 0.4 cm to obtain the mixed plant essential oil raw material; 2) Place the mixed plant essential oil raw material obtained in step 1) in water according to the mass - to - volume ratio of the mixed plant essential oil raw material to water of 1:5, perform steam distillation at 100 °C for 3 h, and separate the oil and water to obtain the mixed plant essential oil; 3. Preparation of the compound microbial inoculant: Mix Bacillus subtilis and Bacillus amyloliquefaciens according to the mass ratio of 1:1 to obtain the compound microbial inoculant; 4. Preparation of the choline - type tobacco root - knot nematode inhibitor: 1) Weigh each raw material according to the following parts by mass: 15 parts of choline derivative, 8 parts of mixed plant essential oil, 4 parts of compound microbial inoculant, 4 parts of emulsifier, and 50 parts of water; 2) Heat the water weighed in step 1) to 55 °C, then add the choline derivative and compound microbial inoculant weighed in step 1) to the heated water, maintain the temperature at 55 °C and stir for 50 min to obtain a pre - mixed solution; 3) Add the mixed plant essential oil and emulsifier weighed in step 1) to the pre - mixed solution obtained in step 2), stir and emulsify at 55 °C for 1.5 h to obtain the choline - type tobacco root - knot nematode inhibitor.

[0039] Effect verification I. Laboratory in - vitro activity test Isolate the second - stage larvae (J2) of tobacco root - knot nematodes from infected tobacco roots and suspend them in sterile water; Add 1 mL of the test reagent (the choline - type tobacco root - knot nematode inhibitors prepared in Examples 1 - 3 and Comparative Examples 1 - 6, with a concentration of 50 ppm) and 100 J2 larvae to each well of a multi - well plate, culture in the dark at 25 °C, and perform microscopic examination at 24 h and 48 h respectively, and calculate the mortality rate (rigid and immobile is regarded as dead). The calculation results of the mortality rate are shown in Table 1; Table 1 Mortality rate (%)

[0040] As can be seen from the data in Table 1, when the choline - type tobacco root - knot nematode inhibitor provided by the present invention directly acts on the second - stage larvae of tobacco root - knot nematodes, the 24 - h mortality rate of the second - stage larvae of tobacco root - knot nematodes can reach 76%, and the 48 - h mortality rate can reach 88%. Compared with the common insecticide abamectin, the choline - type tobacco root - knot nematode inhibitor provided by the present invention has a better direct killing effect on tobacco root - knot nematodes.

[0041] II. Pot experiment Sow K326 tobacco seeds in cultivation pots (5 plants are sown in each cultivation pot). Two weeks after sowing, inoculate 1000 J2 larvae into each cultivation pot. 24 hours after inoculation, apply the drug by drenching the roots at a rate of 50 mL / plant (choline-based tobacco root-knot nematode inhibitors prepared in Examples 1 to 3 and Comparative Examples 1 to 6, with a concentration of 50 ppm; abamectin, with a concentration of 50 ppm; clear water). Three weeks after the end of the drug application, detect the nematode quantity and plant growth indexes. The detection results of the pot experiment are shown in Table 2; Table 2 Detection Results of Pot Experiment

[0042] As can be seen from the data in Table 2, after the choline-based tobacco root-knot nematode inhibitor provided by the present invention is applied by drenching the roots, the root-knot index can reach 1, the nematode reduction rate can reach 82%, the plant height can reach 117 cm, and the SPAD value can reach 42. This indicates that the choline-based tobacco root-knot nematode inhibitor provided by the present invention has a good inhibitory effect on tobacco root-knot nematodes and can effectively block the parasitic channels of root-knot nematodes and restore the normal growth of plants.

[0043] III. Biosafety Detection Conduct biosafety detection on the choline-based tobacco root-knot nematode inhibitor prepared in Example 2. After detection, when the choline-based tobacco root-knot nematode inhibitor with a concentration of 1000 ppm is sprayed on the surface of K326 tobacco leaves, there are no symptoms such as leaf burning and deformity; After detection, the mortality rate of bees is only 23% 48 hours after contacting the choline-based tobacco root-knot nematode inhibitor with a concentration of 1000 ppm, showing low contact toxicity to bees.

[0044] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit them. Although the present invention has been described in detail with reference to the above embodiments, those of ordinary skill in the art should understand that: still modifications or equivalent substitutions can be made to the specific embodiments of the present invention, and any modification or equivalent substitution that does not depart from the spirit and scope of the present invention should be covered by the protection scope of the claims of the present invention.

Claims

1. A choline-based tobacco root-knot nematode inhibitor, characterized in that, It comprises the following raw materials in parts by mass: 10 - 20 parts of choline derivative, 5 - 10 parts of mixed plant essential oil, 3 - 5 parts of compound microbial inoculum, 1 - 3 parts of sodium alginate, 3 - 5 parts of emulsifier and 40 - 60 parts of water.

2. The choline-based tobacco root-knot nematode inhibitor according to claim 1, wherein The structural formula of the choline derivative is as follows: .

3. A choline-based tobacco root-knot nematode inhibitor according to claim 1, characterized in that, The preparation method of the choline derivative comprises the following steps: Firstly, choline chloride is dissolved in dichloromethane to form a choline chloride solution. Then, triethylamine is added to the choline chloride solution to form a mixed solution. Finally, 4-fluorobenzoyl chloride is added dropwise to the mixed solution. After the dropwise addition is completed, a reaction is carried out and purification is performed to obtain the choline derivative.

4. The choline-based tobacco root-knot nematode inhibitor according to claim 3, characterized in that, The molar ratio of choline chloride, triethylamine and 4-fluorobenzoyl chloride is 1∶1.2∶1; the dropping rate of the dropwise addition is 30 d / min; the specific reaction is: reacting at room temperature for 6 h; the specific purification is: filtering, washing successively with 5% dilute hydrochloric acid, saturated sodium bicarbonate and water, and rotary evaporation.

5. A choline-based tobacco root-knot nematode inhibitor according to claim 1, wherein, The preparation method of the mixed plant essential oil comprises the following steps: 1) Mix mint leaves and rosemary branches and leaves, and crush them to obtain the raw material of the mixed plant essential oil; 2) Place the raw material of the mixed plant essential oil obtained in step 1) in water, carry out steam distillation, and separate oil and water to obtain the mixed plant essential oil.

6. The choline-based tobacco root-knot nematode inhibitor according to claim 5, characterized in that, In step 1), the mass ratio of mint leaves to rosemary branches and leaves is 1∶(0.4 - 0.6).

7. A choline-based tobacco root-knot nematode inhibitor according to claim 5, characterized in that, In step 2), the mass - to - volume ratio of the raw material of the mixed plant essential oil to water is 1∶(4 - 6); in step 2), the specific steam distillation is: carrying out steam distillation at 95 - 105°C for 2 - 4 h.

8. A choline-based tobacco root-knot nematode inhibitor according to claim 1, wherein, The compound microbial inoculum is composed of Bacillus subtilis and Bacillus amyloliquefaciens mixed in a mass ratio of 1∶1.

9. A preparation method of the choline-based tobacco root-knot nematode inhibitor according to any one of claims 1 to 8, characterized in that, It comprises the following steps: 1) Add the choline derivative, compound microbial inoculum and sodium alginate into water, and stir to obtain a premixed solution; 2) Add the mixed plant essential oil and emulsifier to the premixed solution obtained in step 1), and stir and emulsify to obtain the choline - based tobacco root - knot nematode inhibitor.

10. According to the preparation method described in claim 9, characterized in that, In step 1), the water needs to be pre - heated to 50 - 60°C; the specific stirring is: maintaining the temperature at 50 - 60°C and stirring for 40 - 60 min; In step 2), the specific stirring and emulsifying is: stirring and emulsifying at 50 - 60°C for 1 - 2 h.

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