Use of a benzamide compound in the prevention and treatment of plant nematodes

Abstract

The application discloses application of a benzamide compound in prevention and treatment of plant root-knot nematodes. N‑ (2-ethyl-1,2,5-thiadiazol-4-yl)-2-iodobenzamide. 2H The application discloses a benzamide compound N‑ (2-ethyl-1,2,5-thiadiazol-4-yl)-2-iodobenzamide. 2H The benzamide compound has strong toxic killing effect on various plant root-knot nematodes, and has no insecticidal activity on non-plant pathogenic nematodes, and has the characteristics of high efficiency, low toxicity and low residue. The application provides a new candidate compound for the prevention and treatment of plant root-knot nematodes, enriches the structure type of the root-knot nematode killing benzamide compound, and provides a new thought and way for development of a new root-knot nematode killing pesticide.

Description

Technical Field

[0001] The invention belongs to the technical field of agricultural pest control, and particularly relates to an application of a benzamide compound in controlling plant root-knot nematodes. Background Art

[0002] Root-knot nematodes are plant-parasitic nematodes and one of the most devastating. They are widely distributed worldwide, have a diverse host population, and can infect thousands of plant species. Severe damage can cause crop yields of over 80% or even total crop failure. Root-knot nematodes primarily infect plant roots. The typical symptom of root damage is the formation of numerous nodular root knots. As the number and size of these knots increase, they severely damage the root system, hindering nutrient absorption and transport, affecting normal plant development, leading to reduced yield and quality, and causing significant economic losses. Currently, root-knot nematode control methods include chemical, agricultural, biological, and chemical control. Chemical control remains dominant due to its rapid effectiveness and ease of use. However, due to the environmental hazards of some developed chemical pesticides and the accumulation of pesticide resistance, many have been banned or discontinued. Therefore, the development of new, highly effective, and environmentally friendly chemical pesticides has become a key issue in root-knot nematode control.

[0003] Benzamide compounds are widely used in the research and development of insecticide compounds, including bromofenac, chlorfenapyr, thiobenzamide (3-bromo- N -[4-chloro-2-methyl-6-(methylaminothiocarbonyl)benzene]-1-(3-chloropyridin-2-yl)- 1H -pyrazole-5-carboxamide), N -(1-cyano-2-hydroxy-1-methyl-ethyl)-4-(trifluoromethylmercapto)benzamide, etc. N- (2-ethyl- 2H There are no reports on the activity of (5-tetrazol-5-yl)-2-iodobenzamide in killing root-knot nematodes. Summary of the Invention

[0004] The object of the present invention is to provide benzamide compounds N- (2-ethyl- 2H Application of 5-tetrazol-5-yl)-2-iodobenzamide in preventing and controlling plant root-knot nematodes.

[0005] The object of the present invention is achieved in that benzamide compounds N- (2-ethyl- 2H -tetrazol-5-yl)-2-iodobenzamide and / or its pesticide-acceptable salt in preventing and controlling plant root-knot nematodes, the benzamide compound N-(2-ethyl- 2H The structural formula of -tetrazol-5-yl)-2-iodobenzamide is shown in Formula I:

[0006]

[0007] I.

[0008] The present invention first discovered N- (2-ethyl- 2H The invention discloses a novel (5-(2-(-tetrazol-5-yl)-2-iodobenzamide) with a strong toxic effect against various plant root-knot nematodes and no insecticidal activity against non-plant pathogenic nematode model nematodes, demonstrating its high efficacy and low toxicity. The invention provides a new candidate compound for plant root-knot nematode control, enriches the structural types of root-knot nematode-killing benzamide compounds, and offers new ideas and approaches for the development of new root-knot nematode pesticides. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 The compound of the present invention N- (2-ethyl- 2H -tetrazol-5-yl)-2-iodobenzamide;

[0010] Figure 2 For the compound in Example 1 N- (2-ethyl- 2H Calculation results of the toxicity test of (-tetrazol-5-yl)-2-iodobenzamide against southern root-knot worm;

[0011] Figure 3 For Example 1 N- (2-ethyl- 2H Calculation results of the toxicity test of 5-tetrazol-5-yl)-2-iodobenzamide against root-knot nematode javanica;

[0012] Figure 4 For Example 1 N- (2-ethyl- 2H The results of the toxicity determination of 5-tetrazol-5-yl)-2-iodobenzamide against root-knot nematode of ear bean were calculated. DETAILED DESCRIPTION

[0013] The present invention will be further described in detail below with reference to the embodiments, but the present invention is not limited in any way. Any changes or improvements made based on the teachings of the present invention fall within the scope of protection of the present invention.

[0014] The present invention provides N- (2-ethyl- 2H -tetrazol-5-yl)-2-iodobenzamide and / or its pesticide-acceptable salt in preventing and controlling plant root-knot nematodes, the compoundN- (2-ethyl- 2H -tetrazol-5-yl)-2-iodobenzamide has the structural formula Figure 1 The compound was purchased from MCE Company with the number HY-Q49539.

[0015]

[0016] I.

[0017] The root-knot nematode is the southern root-knot nematode, the northern root-knot nematode, the Java root-knot nematode, the peanut root-knot nematode or the elephant-ear bean root-knot nematode.

[0018] The present invention also provides an insecticide for controlling plant root-knot nematodes, wherein the insecticide is a compound N- (2-ethyl- 2H -tetrazol-5-yl)-2-iodobenzamide and / or its pesticide-acceptable salt is the main active ingredient or one of the active ingredients. N- (2-ethyl- 2H The mass concentration of 5-tetrazol-5-yl)-2-iodobenzamide is 0.5-50 μg / ml.

[0019] The dosage form of the insecticide is aqueous solution, aqueous emulsion, wettable powder, soluble powder, soluble granule, suspension, tablet or effervescent granule.

[0020] The solvent of the aqueous solution or aqueous emulsion is a fatty alcohol aqueous solution or a dimethyl sulfoxide aqueous solution with a concentration of ≤10%.

[0021] The fatty alcohols include but are not limited to methanol, ethanol and propanol.

[0022] Example 1 N- (2-ethyl- 2H Nematicidal activity assay of (5-tetrazol-2-yl)-2-iodobenzamide

[0023] 1. Sample preparation

[0024] 0.5-1.5 mg N- (2-ethyl- 2H 2-(2-(-tetrazol-5-yl)-2-iodobenzamide was dissolved in DMSO and diluted with 4% DMSO solution to serve as the test solution. The dilution concentrations of each solution were: 0.03 μg / ml, 0.05 μg / ml, 0.1 μg / ml, 0.3 μg / ml, 0.5 μg / ml, 1 μg / ml, 3 μg / ml, 5 μg / ml, 10 μg / ml, 30 μg / ml, and 50 μg / ml. The DMSO concentration in each solution was 0.4%. Water containing 0.4% DMSO served as a blank control.

[0025] 2. Preparation of Nematodes for Experimental Use

[0026] Tomato roots infected with southern root-knot nematodes were washed with water. Oocysts were picked with a dissecting needle and placed in a 0.4 M KCl solution. In a 5 ml centrifuge tube, the roots were washed and disinfected three times with 4 ml of sterile water, 1 ml of sterile penicillin-streptomycin solution, and 3 ml of 0.1% NaClO solution. The supernatant was removed by brief centrifugation at each step (8000 rpm for 30 seconds). The washed eggs were incubated in a 0.4 M ZnCl2 solution for 48 hours. Second-instar larvae were collected with a pipette into a 1.5 ml centrifuge tube and enriched by brief centrifugation at 5000 rpm for 30 seconds.

[0027] In addition, this experiment also prepared experimental nematodes such as Java root-knot nematode, elephant ear bean root-knot nematode and Caenorhabditis elegans according to conventional methods.

[0028] 3. Test methods

[0029] Transfer 100 μl of each test solution prepared in step 1 to a 20-well plate. Add 50-100 live nematodes prepared in step 2. Incubate at 25°C and calculate nematode mortality under a light microscope after 24, 48, and 72 hours. Identify nematode mortality by adding 1-5 drops of 5% NaCl solution to the treated wells. After 2 minutes, observe. Dead nematodes will be rigid and unresponsive to needle stimulation. Live nematodes will curl or twist.

[0030] The test solution without sample was used as the control, and the whole experiment was repeated three times. The average of the three times was taken to calculate the corrected mortality rate.

[0031] Mortality % = (number of dead nematodes / (number of dead nematodes + number of surviving nematodes)) × 100%

[0032] Corrected mortality % = sample mortality – control mortality

[0033] 4. Experimental results

[0034] 4.1 N- (2-ethyl- 2H The toxicity of 5-tetrazolyl-2-iodobenzamide to southern root-knot nematodes is shown in Table 1 and Figure 2 As shown:

[0035] Table 1 N- (2-ethyl- 2H Toxic effects of (5-tetrazolyl)-2-iodobenzamide on southern root-knot nematodes

[0036]

[0037] 4.2N- (2-ethyl- 2H The toxicity of 5-tetrazolyl-2-iodobenzamide to root-knot nematodes is shown in Table 2 and Figure 3 shown.

[0038] Table 2 N- (2-ethyl- 2H Toxicity of 5-tetrazolyl-2-iodobenzamide to root-knot nematodes

[0039]

[0040] 4.3 N- (2-ethyl- 2H The toxicity of (-tetrazol-5-yl)-2-iodobenzamide to root knot nematodes of ear bean is shown in Table 3 and Figure 4 As shown:

[0041] Table 3 N- (2-ethyl- 2H The toxicity of (5-tetrazolyl)-2-iodobenzamide to root-knot nematodes of ear bean

[0042]

[0043] 4.4 N- (2-ethyl- 2H -tetrazol-5-yl)-2-iodobenzamide had no toxic activity against the non-plant pathogenic nematode Caenorhabditis elegans within 24 hours.

[0044] Result analysis: After determination ( Figure 2-4 ), N- (2-ethyl- 2H The median lethal dose (LC50) of (-tetrazol-5-yl)-2-iodobenzamide against southern root-knot nematodes, javanic root-knot nematodes and elephant-ear bean root-knot nematodes in 24 hours 50 The concentrations were 2.21 μg / ml, 2.35 μg / ml and 13.81 μg / ml respectively; the median lethal dose LC50 of the southern root-knot nematode, the javanic root-knot nematode and the elephant-ear root-knot nematode was 2.21 μg / ml, 2.35 μg / ml and 13.81 μg / ml respectively; the median lethal dose LC50 of 50 The concentrations are 2.14 μg / ml, 1.93 μg / ml and 8.90 μg / ml respectively. They have a strong toxic effect on plant root-knot nematodes such as southern root-knot nematode, javanic root-knot nematode and elephant-ear bean root-knot nematode, but have no toxic activity against non-plant pathogenic nematode Caenorhabditis elegans. They can be used for the prevention and control of plant root-knot nematodes.

[0045] Example 2

[0046] An insecticide for controlling plant root knot nematodes, the insecticide uses a 7% ethanol solution as a solvent and a concentration of 30 μg / mlN- (2-ethyl- 2H -tetrazol-5-yl)-2-iodobenzamide is the active ingredient.

[0047] Example 3

[0048] An insecticide for controlling plant root knot nematodes, the insecticide is prepared by using a 3% methanol solution as a solvent and a concentration of 10 μg / ml. N- (2-ethyl- 2H -tetrazol-5-yl)-2-iodobenzamide is the active ingredient.

[0049] Example 4

[0050] An insecticide for controlling plant root-knot nematodes, the insecticide uses a 4% dimethyl sulfoxide aqueous solution as a solvent and a concentration of 20 μg / ml N- (2-ethyl- 2H -tetrazol-5-yl)-2-iodobenzamide is the active ingredient.

[0051] The above embodiments are preferred implementation modes of the present invention, but the implementation modes of the present invention are not limited to the above embodiments. Any other changes, modifications, substitutions, combinations, and simplifications that do not deviate from the spirit and principles of the present invention should be considered as equivalent replacement methods and are included in the scope of protection of the present invention.

Claims

1. N- (2-ethyl- 2H -tetrazol-5-yl)-2-iodobenzamide and / or its pesticide-acceptable salt in controlling plant root-knot nematodes, characterized in that: described N- (2-ethyl- 2H -tetrazol-5-yl)-2-iodobenzamide structural formula is shown in Formula I: I； The concentration of N-(2-ethyl-2H-tetrazol-5-yl)-2-iodobenzamide is 0.5-50 μg / ml.

2. The application according to claim 1, characterized in that The root-knot nematode is the southern root-knot nematode, the northern root-knot nematode, the Java root-knot nematode, the peanut root-knot nematode or the elephant-ear bean root-knot nematode.

3. An insecticide for controlling plant root-knot nematodes, characterized in that: The insecticide is a compound N- (2-ethyl- 2H -tetrazol-5-yl)-2-iodobenzamide and / or its pesticide-acceptable salts are active ingredients, N- (2-ethyl- 2H The concentration of 5-tetrazol-5-yl)-2-iodobenzamide is 0.5-50 μg / ml, and the solvent is a fatty alcohol aqueous solution or a dimethyl sulfoxide aqueous solution with a concentration of ≤10%.

4. The insecticide according to claim 3, characterized in that The dosage form of the insecticide is aqueous solution, aqueous emulsion, wettable powder, soluble powder, soluble granule, suspension, tablet or effervescent granule.

5. The insecticide according to claim 3, characterized in that The fatty alcohol is methanol, ethanol or propanol.

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