Use of N-(1-acetyl-2,3-dihydro-1H-indol-6-yl)-2,6-difluorobenzamide in the control of plant nematodes

Abstract

The present invention discloses the use of N-(1-acetyl-2,3-dihydro-1H-indol-6-yl)-2,6-difluorobenzamide in preventing and controlling plant root-knot nematodes. The present invention is the first to discover that N-(1-acetyl-2,3-dihydro-1H-indol-6-yl)-2,6-difluorobenzamide has a strong toxic effect on a variety of plant root-knot nematodes, with a median lethal dose (LC50) of 100% for southern root-knot nematodes, javanic root-knot nematodes, and elephant ear bean root-knot nematodes within 24 hours. 50 The concentrations were 4.27 μg / ml, 8.38 μg / ml and 7.51 μg / ml respectively; the median lethal dose LC of the southern root-knot nematode, the javanic root-knot nematode and the elephant-ear root-knot nematode was 48 hours. 50 The concentrations are 4.11 μg / ml, 9.56 g / ml and 6.92 μg / ml respectively. It has no toxic activity against non-plant pathogenic nematodes such as Caenorhabditis elegans, has the characteristics of high efficiency and low toxicity, and can be used in the development and research of root-knot nematode insecticides.

Description

Technical Field

[0001] The invention belongs to the technical field of agricultural pest control, and particularly relates to application of N-(1-acetyl-2,3-dihydro-1H-indol-6-yl)-2,6-difluorobenzamide in controlling plant root-knot nematodes. Background Art

[0002] Plant parasitic nematodes are one of the plant pathogens that seriously threaten global agricultural security. It is estimated that the agricultural economic losses caused by plant parasitic nematodes exceed hundreds of billions of US dollars each year, and root-knot nematodes are one of the most destructive pathogenic nematodes. Root-knot nematodes include hundreds of species, among which the southern root-knot nematode ( Meloidogyne incognita ), peanut root knot nematode ( Meloidogyne arenaria ), northern root-knot nematode ( Meloidogyne hapla ), javanic root-knot nematode ( Meloidogyne javanica ) is the most serious harm to crops. Root-knot nematodes have a wide host range, including most crops such as woody, monocotyledonous and dicotyledonous herbs. Root-knot nematodes are widely distributed around the world and cause serious damage, causing great harm to the yield and quality of crops. At present, the prevention and control of root-knot nematodes is mainly based on chemical control. The chemical control drugs that have been developed and applied include thiazophos, avermectin, chlorpyrifos, and dazomet, but most of the chemical control drugs are more harmful to the environment, and with the accumulation of drug resistance of root-knot nematodes, the efficacy is getting lower and lower, resulting in most chemical control drugs being banned or abandoned. The prevention and control of root-knot nematodes faces huge challenges. At present, there is an urgent need to develop some new chemical control drugs that are environmentally friendly and highly effective to cope with the increasingly serious root-knot nematode diseases. Summary of the Invention

[0003] The purpose of the present invention is to provide an application of N-(1-acetyl-2,3-dihydro-1H-indol-6-yl)-2,6-difluorobenzamide in preventing and controlling plant root-knot nematodes.

[0004] The object of the present invention is achieved by using N-(1-acetyl-2,3-dihydro-1H-indol-6-yl)-2,6-difluorobenzamide and / or its pesticide-acceptable salts in controlling plant root-knot nematodes. The structural formula of N-(1-acetyl-2,3-dihydro-1H-indol-6-yl)-2,6-difluorobenzamide is shown in Formula I:

[0005]

[0006] I.

[0007] The present invention first discovered that N-(1-acetyl-2,3-dihydro-1H-indol-6-yl)-2,6-difluorobenzamide has a strong toxic effect on a variety of plant root-knot nematodes. The median lethal dose (LC50) of N-(1-acetyl-2,3-dihydro-1H-indol-6-yl)-2,6-difluorobenzamide against southern root-knot nematodes, javanic root-knot nematodes and elephant ear bean root-knot nematodes within 24 hours is 0. 50 The concentrations were 4.27 μg / ml, 8.38 μg / ml and 7.51 μg / ml respectively; the median lethal dose LC of the southern root-knot nematode, the javanic root-knot nematode and the elephant-ear root-knot nematode was 48 hours. 50 The concentrations are 4.11 μg / ml, 9.56 g / ml and 6.92 μg / ml respectively. It has no toxic activity against non-plant pathogenic nematodes such as Caenorhabditis elegans, has the characteristics of high efficiency and low toxicity, and can be used in the development and research of root-knot nematode insecticides. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Figure 1 is the structural formula of the compound N-(1-acetyl-2,3-dihydro-1H-indol-6-yl)-2,6-difluorobenzamide of the present invention;

[0009] Figure 2 The calculation results of the toxicity determination of N-(1-acetyl-2,3-dihydro-1H-indol-6-yl)-2,6-difluorobenzamide against southern root knot worm in Example 1;

[0010] Figure 3 The calculation results of the toxicity determination of N-(1-acetyl-2,3-dihydro-1H-indol-6-yl)-2,6-difluorobenzamide against javanica root-knot nematode in Example 1 are shown;

[0011] Figure 4 The toxicity test of N-(1-acetyl-2,3-dihydro-1H-indol-6-yl)-2,6-difluorobenzamide against the ear bean root knot nematode in Example 1 was carried out.

[0012] Calculate the result. 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 the use of N-(1-acetyl-2,3-dihydro-1H-indol-6-yl)-2,6-difluorobenzamide and / or its pesticide-acceptable salt in controlling plant root-knot nematodes. The structural formula of the compound N-(1-acetyl-2,3-dihydro-1H-indol-6-yl)-2,6-difluorobenzamide is as follows: Figure 1The compound is purchased from MCE Company, No. HY-Q24662, with a relative molecular mass of 316.30 and mass-to-charge ratios of 316.10 (100.0%), 317.11 (18.4%), and 318.11 (1.6%).

[0015]

[0016] I.

[0017] The root-knot nematode is southern root-knot nematode, northern root-knot nematode, guava root-knot nematode, peanut root-knot nematode, or cowpea root-knot nematode.

[0018] The present application also provides an insecticide for controlling plant root-knot nematodes, which contains N-(1-acetyl-2,3-dihydro-1H-indol-6-yl)-2,6-difluorobenzamide and / or a salt thereof as a main active ingredient or one of the active ingredients. The mass concentration of N-(1-acetyl-2,3-dihydro-1H-indol-6-yl)-2,6-difluorobenzamide in the insecticide is 0.5-50 μg / ml.

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

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

[0021] The fatty alcohol includes but is not limited to methanol, ethanol, and propanol.

[0022] Example 1: N-(1-acetyl-2,3-dihydro-1H-indol-6-yl)-2,6-difluorobenzamide nematocidal activity test

[0023] 1. Sample preparation

[0024] 0.5-1.5 mg of N-(1-acetyl-2,3-dihydro-1H-indol-6-yl)-2,6-difluorobenzamide was dissolved in DMSO, and the solution was diluted with a 4% DMSO solution to serve as the test drug solution. The dilution concentrations of the drug solutions 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, respectively, and the mass concentration of DMSO in each drug solution was 0.4%. Water containing 0.4% DMSO was used as a blank control. N-(1-Acetyl-2,3-dihydro-1H-indol-6-yl)-2,6-difluorobenzamide

[0025] 2. Preparation of test nematodes

[0026] ​The tomato roots infected by southern root-knot nematode were washed with water, and the egg capsules of root-knot nematode were picked up with a dissecting needle and placed in 0.4 M KCl solution. The egg capsules were washed and sterilized with 4 ml sterile water (three times), 1 ml sterile ampicillin and streptomycin double-antibiotic solution, and 3 ml 0.1% NaClO solution in 5 ml centrifuge tubes, respectively. The supernatant was removed by short-term centrifugation (8000 rpm for 30 seconds) after each step. The washed eggs were incubated in 0.4 M ZnCl2 solution for 48 hours, and the second instar larvae were collected in 1.5 ml centrifuge tubes by short-term centrifugation (5000 rpm for 30 seconds) for standby.

[0027] In addition, the test nematodes, such as Meloidogyne javanica, M. enterolobii, and Caenorhabditis elegans, were prepared according to conventional methods.

[0028] 3. Test method

[0029] 100 μl of each test solution prepared in step 1 was taken in a 20-well plate, 50-100 live nematodes prepared in step 2 were added, and the plate was placed at 25°C. The mortality of nematodes was observed and calculated under an optical microscope at 24 hours, 48 hours, and 72 hours, respectively. The method for identifying dead nematodes was as follows: 1-5 drops of 5% NaCl solution were added to the well of the test plate, and after 2 minutes, dead nematodes were observed to be stiff and unresponsive to needle stimulation, while live nematodes were observed to be curled or wriggling.

[0030] The test solution without the sample was used as a control, and the entire experiment was repeated three times. The corrected mortality was calculated based on the average of the three times.

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

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

[0033] 4. Experimental results

[0034] 4.1 N-(1-Acetyl-2,3-dihydro-1H-indol-6-yl)-2,6-difluorobenzamide The toxic effects on southern root-knot nematodes are shown in Table 1.

[0035] Table 1 N-(1-Acetyl-2,3-dihydro-1H-indol-6-yl)-2,6-difluorobenzamide Toxic effects on southern root-knot nematodes

[0036]

[0037] 4.2 N-(1-Acetyl-2,3-dihydro-1H-indol-6-yl)-2,6-difluorobenzamide The toxic effects on Java root-knot nematodes are shown in Table 2.

[0038] Table 2 N-(1-Acetyl-2,3-dihydro-1H-indol-6-yl)-2,6-difluorobenzamide Toxic effects on Java root-knot nematodes

[0039]

[0040] 4.3 N-(1-Acetyl-2,3-dihydro-1H-indol-6-yl)-2,6-difluorobenzamide The toxicity against root-knot nematodes of the ear bean is shown in Table 3:

[0041] Table 3 N-(1-Acetyl-2,3-dihydro-1H-indol-6-yl)-2,6-difluorobenzamide The results of killing root knot nematodes on the ear bean

[0042]

[0043] 4.4 N-(1-Acetyl-2,3-dihydro-1H-indol-6-yl)-2,6-difluorobenzamide It had no toxic activity against the non-plant pathogenic nematode Caenorhabditis elegans at 24 hours.

[0044] Result analysis: After determination ( Figure 2-4 ), N-(1-Acetyl-2,3-dihydro-1H-indol-6-yl)-2,6-difluorobenzyl Amide The median lethal dose (LC) of the southern root-knot nematode, the javanic root-knot nematode and the elephant-ear bean root-knot nematode was 24 hours. 50 The concentrations were 4.27 μg / ml, 8.38 μg / ml and 7.51 μg / ml respectively; the median lethal dose LC of the southern root-knot nematode, the javanic root-knot nematode and the elephant-ear root-knot nematode was 48 hours. 50 The concentrations are 4.11 μg / ml, 9.56 g / ml and 6.92 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 is prepared by using a 5% ethanol solution as a solvent and a concentration of 30 μg / ml N-(1-Acetyl-2,3-dihydro-1H-indol-6-yl)-2,6-difluorobenzamide For the active ingredient.

[0047] Example 3

[0048] An insecticide for controlling plant root knot nematodes, the insecticide uses a 4% dimethyl sulfoxide solution as a solvent and a concentration of 10 μg / ml N-(1-Acetyl-2,3-dihydro-1H-indol-6-yl)-2,6-difluorobenzamide For the active ingredient.

[0049] Example 4

[0050] An insecticide for controlling plant root knot nematodes, the insecticide is prepared by using a 2% methanol solution as a solvent and a concentration of 20 μg / ml. N-(1-Acetyl-2,3-dihydro-1H-indol-6-yl)-2,6-difluorobenzamide For the active ingredient.

[0051] Example 5

[0052] An insecticide for controlling plant root knot nematodes, the insecticide is prepared by using 8% propanol solution as solvent and a concentration of 50 μg / ml N-(1-Acetyl-2,3-dihydro-1H-indol-6-yl)-2,6-difluorobenzamideFor the active ingredient.

[0053] 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. Use of N-(1-acetyl-2,3-dihydro-1H-indol-6-yl)-2,6-difluorobenzamide and / or its pesticide-acceptable salts in controlling plant root-knot nematodes, wherein the concentration of the N-(1-acetyl-2,3-dihydro-1H-indol-6-yl)-2,6-difluorobenzamide is 10-50 μg / ml.

2. The application according to claim 1, characterized in that The root-knot nematode is the southern root-knot nematode, the Java 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 for controlling plant root-knot nematodes contains N-(1-acetyl-2,3-dihydro-1H-indol-6-yl)-2,6-difluorobenzamide and / or its pesticide-acceptable salts as active ingredients. The concentration of N-(1-acetyl-2,3-dihydro-1H-indol-6-yl)-2,6-difluorobenzamide in the insecticide is 10-50 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, water-dispersible granule, suspension, oil 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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