Bactericidal composition for preventing and treating corn grey leaf spot

Abstract

The invention belongs to the technical field of prevention and treatment of corn gray leaf spot, and particularly relates to a bactericidal composition for preventing and treating corn gray leaf spot. The invention relates to a sterilization composition. The effective components of the sterilization composition are formed by compounding L-carvone and flutriafol or 1-(2-hydroxyphenyl)-1-(1-hydroxyphenyl)-1-(1-hydroxyphenyl)-1-(1-hydroxyphenyl The L-carvone and the existing bactericide are compounded and screened, and when the L-carvone is compounded with flutriafol or 1-(2-hydroxyphenyl)-1-(1-hydroxyphenyl)-1-(1-hydroxyphenyl)-1-(1-hydroxyphenyl)-1-(1-hydroxyphenyl)-1-(1-hydroxyphenyl)-1-(1-hydroxyphenyl)-1-(1-hydroxyphenyl)-1-(1-hydroxyphenyl)-1-(1-hydroxyphenyl)-1-(1-hydroxyphenyl)-1-(1-

Description

Technical Field

[0001] This invention belongs to the field of corn gray spot disease control technology, specifically relating to a bactericidal composition for controlling corn gray spot disease. Background Technology

[0002] The later stages of corn growth are a period of high incidence and prevalence of diseases, especially stalk rot and gray leaf spot. Gray leaf spot is one of the most significant diseases affecting corn in my country's corn-producing areas, and it can be caused by *Cercospora zeylanica* (…). Cerospora zeae-maydis Tehon & Daniels) and Cercospora cornica ( Cercospora zeina This disease is caused by infections such as [insects]. In actual production, breeding disease-resistant varieties is the most effective way to control corn gray leaf spot. However, due to the scarcity of disease-resistant resources and the difficulty in planting disease-resistant varieties across the board, chemical control is a fast and effective method. However, single-agent pesticides can easily cause pathogens to develop resistance. Therefore, screening compound formulations that have a synergistic effect against corn gray leaf spot is of great significance.

[0003] L-carvone, CAS: 6485-40-1, molecular formula: C 10 H 14 O, the structural formula is as follows:

[0004] L-carvone is a pale yellow, clear liquid that is poorly soluble in water. It is the main component of the volatile oil extracted from spearmint, a perennial herbaceous plant belonging to the genus *Mentha* of the Lamiaceae family. Existing technologies have reported that L-carvone exhibits antifungal activity against various plant pathogenic fungi, suggesting its potential for development into crop fungicides.

[0005] Currently, there are no reports of combining L-carvone with fenbendazole or fenbendazole.

[0006] The information disclosed in this background section is intended only to enhance the understanding of the overall background of the invention and should not be construed as an admission or in any way implying that the information constitutes prior art known to those skilled in the art. Summary of the Invention

[0007] The purpose of this invention is to provide a fungicidal composition for controlling gray spot disease of corn, so as to solve the problems existing in the control of gray spot disease of corn using a single agent.

[0008] To achieve the above objectives, the present invention provides the following technical solution: A bactericidal composition, wherein the active ingredient of the bactericidal composition is a compound of levamisole and fenbendazole or fenbendazole.

[0009] Preferably, the mass ratio of L-carvone to triamcinolone is 1-20:5-1.

[0010] For even better results, the mass ratio of L-carvone to triamcinolone is 1:5.

[0011] Preferably, the mass ratio of L-carvone to phenolic ketone is 1-30:30-1.

[0012] For even better results, the mass ratio of L-carvone to phenolic ketone is 30:1.

[0013] The present invention also provides the application of the bactericidal composition in the prevention or control of gray spot disease in corn.

[0014] Specifically, the pathogen causing the gray spot disease in corn is *Cercospora zeatans*.

[0015] Compared with the prior art, the present invention has the following beneficial effects: This invention screens existing agents by combining levonorgestrel with carvone and finds that when it is combined with triamcinolone or fenbendazole in a certain mass ratio, the compound formulation exhibits a synergistic effect on the growth of the corn gray spot pathogen, which can improve the control effect and provide support for the development of fungicides for the control of corn gray spot. Detailed Implementation

[0016] The technical solution of this invention patent will be clearly and completely described below. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without inventive effort are within the scope of protection of this invention.

[0017] Example Indoor activity test 1. Test pathogens Leaves from plants exhibiting typical maize gray spot disease were collected, and after isolation, purification, and identification, the pathogen was determined to be *Cercospora zeylindrica* (a type of fungus). Cerospora zeae-maydis Tehon & Daniels).

[0018] 2. Culture medium Maize leaf powder calcium carbonate agar medium (MLPCA): 15g maize leaf powder, 2g calcium carbonate, 15g agar, 1L distilled water, autoclave at 121℃ for 40min, cool and set aside.

[0019] 3. Test reagents 99% carvone technical grade, 95% fenbendazole technical grade, and 98% fenpropathrin technical grade are all commercially available.

[0020] After dissolving the test reagent, multiple ratios were set up. Five series of mass concentration gradients were set up for each single agent and each group of mixed reagents according to the equal ratio method, and then set up for use.

[0021] 4. Prepare spore suspension The tested strain was inoculated onto MLPCA agar plates and cultured at 26°C for 5 days. The conidia that had grown on the medium were washed off with 1% Tween 20 solution, and then diluted with sterile water to prepare a 1.0 × 10⁻⁶ m³ / g plate. 5 A spore suspension of 1 spore / mL is prepared for later use.

[0022] 4. Test Methods The virulence of single-agent stock solutions and multi-agent mixtures against the tested strain *Cercospora zeylans* was determined using the filter paper disc method.

[0023] Take 100 μL of spore suspension and spread it evenly on the surface of cooled MLPCA agar plates (9 cm in diameter). Punch 5 mm diameter filter paper discs, add 10 μL of the drug solution to each disc, and place them in the center of each MLPCA agar plate. Place one filter paper disc on each plate, with a filter paper disc containing an equal volume of sterile water serving as a blank control. Each treatment is repeated 5 times. Incubate in the dark at 26℃ for 7 days. Measure the diameter of the inhibition zone using the cross-hatching method and calculate the inhibition rate.

[0024]

[0025] 4. Data Analysis Data statistical analysis was performed using DPS software. Linear regression was conducted with the logarithm of fungicide concentration as x and the corresponding mycelial growth inhibition probability value as y to derive the virulence regression equation and the EC50 of the fungicide against the target pathogen. 50 The value was calculated, and the cotoxicity coefficient (CTC) was calculated according to Sun Yunpei's method.

[0026]

[0027] In the above formula: ATI --The measured toxicity index of the mixture; S --EC of standard reagents 50 Value, in mg / L; M -- EC of the mixture 50 Value, in μg / mL.

[0028]

[0029] In the above formula: TTI --Theoretical toxicological index of the mixture; TI A --Toxicity index of drug A; P A--Percentage content of drug A in the mixture, expressed as percentage (%). TI B --Toxicity index of drug B; P B --The percentage content of drug B in the mixture, expressed as a percentage (%).

[0030]

[0031] In the above formula: CTC --Cotoxicity coefficient; ATI --Measured toxicity index of the mixture; TTI --Theoretical toxicity index of mixed formulations.

[0032] 5. Measurement Results The synergistic effect of the drug was evaluated based on the calculated co-toxicity coefficient (CTC). CTC ≤ 80 indicates antagonistic effect, 80 < CTC < 120 indicates additive effect, and CTC ≥ 120 indicates synergistic effect. The results are shown in Table 1-2.

[0033] Table 1. Indoor bioactivity assay of the combination of levonorgestrel and triamcinolone against *Cephalotaxus fortunei*. Drug Name and Proportion <![CDATA[EC 50 (μg / mL)]]> ATI TTI CTC L-carvone 8.2210 100.0000 -- -- Piperazol 3.5208 233.4981 -- -- L-carvone 1: 5-carvone 0.8193 1003.4176 211.2484 474.9942 L-carvone 1: 3 fenazol 1.3701 600.0292 200.1236 299.8294 L-carvone 1: piracetam 1 3.3977 241.9578 166.7490 145.1030 L-carvone 3: piracetam 1 4.4551 184.5301 133.3745 138.3548 L-carvone 5: piracetam 1 5.3109 154.7949 122.2497 126.6219 L-carvone 10: mitoxazone 1 5.9827 137.4129 112.1362 122.5411 L-carvone 20: mitoxazone 1 5.1534 159.5257 106.3571 149.9908 As shown in Table 1, the co-toxicity coefficients of the active ingredient levonorgestrel and triamcinolone against corn gray spot pathogens were all greater than 120 within a mass ratio range of 1-20:5-1, demonstrating a synergistic effect. In particular, when the mass ratio of the two was 1:5, the co-toxicity coefficient reached 474.9942, and the synergistic effect was the most significant.

[0034] Table 2. Indoor bioactivity assay of the combination of levonorgestrel and fenvalerate against *Cephalotaxus fortunei*. Drug Name and Proportion <![CDATA[EC 50 (μg / mL)]]> ATI TTI CTC L-carvone 8.2210 100.0000 -- -- Phenytoxin 5.1662 159.1305 -- -- L-carvone 1: Phenytoxin 30 3.8439 213.8713 157.2231 136.0305 L-carvone 1: Phenytoxin 20 2.9641 277.3523 156.3148 177.4319 L-carvone 1: Phenytoxin 10 2.5645 320.5693 153.7550 208.4936 L-carvone 1: Phenytoxin 5 3.3363 246.4107 149.2754 165.0712 L-carvone 1: Phenytoxin 1 4.0726 201.8612 129.5653 155.7989 L-carvone 5: Phenytoxin 1 3.0393 270.4899 109.8551 246.2243 L-carvone 10: Phenytoxin 1 6.1365 133.9689 105.3755 127.1347 L-carvone 20: Phenytoxin 1 4.0370 203.6413 102.8157 198.0643 L-carvone 30: Phenytoxin 1 1.1802 696.5769 101.9074 683.5388 As shown in Table 2, the co-toxicity coefficients of the active ingredients, L-carvone and phenoxybenzanone, against corn gray spot pathogens were all greater than 120 within a mass ratio range of 1-30:30-1, demonstrating a synergistic effect. In particular, when the mass ratio of the two was 30:1, the co-toxicity coefficient reached 683.5388, indicating the most significant synergistic effect.

[0035] In summary, this invention screened and combined L-carvone with existing fungicides, and found that when it was combined with triamcinolone or fenbendazim in a certain mass ratio, the compound formulation showed a synergistic effect on the growth of the corn gray spot pathogen, which can improve the control effect and provide support for the development of fungicides for the control of corn gray spot.

[0036] The foregoing description of specific exemplary embodiments of the invention is for illustrative and explanatory purposes. These descriptions are not intended to limit the invention to the precise forms disclosed, and it will be apparent that many changes and variations can be made in accordance with the foregoing teachings. The exemplary embodiments were chosen and described in order to explain the specific principles of the invention and its practical application, thereby enabling those skilled in the art to implement and utilize various different exemplary embodiments of the invention, as well as various different choices and variations. The scope of the invention is intended to be defined by the claims and their equivalents.

Claims

1. A bactericidal composition, characterized in that, The active ingredient of the bactericidal composition is a compound of levamisole and fenbendazole or fenbendazole.

2. The bactericidal composition according to claim 1, characterized in that, The mass ratio of L-carvone to triamcinolone is 1-20:5-1.

3. The bactericidal composition according to claim 2, characterized in that, The mass ratio of L-carvone to triamcinolone is 1:

5.

4. The bactericidal composition according to claim 1, characterized in that, The mass ratio of L-carvone to phenoxybenzyl is 1-30:30-1.

5. The bactericidal composition according to claim 4, characterized in that, The mass ratio of L-carvone to phenoxybenzyl is 30:

1.

6. The use of the bactericidal composition according to any one of claims 1-5 in the prevention or control of gray spot disease in corn.

7. The application according to claim 6, characterized in that, The pathogen causing the gray spot disease in corn is *Cercospora zeylanica* (…). Cerospora zeae-maydis Tehon & Daniels).

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