Hydroxychloroquine compound pesticide composition for preventing and treating plant pathogenic fungi and application of hydroxychloroquine compound pesticide composition

Abstract

The invention discloses a hydroxychloroquine compound pesticide composition for preventing and treating plant pathogenic fungi and application of the hydroxychloroquine compound pesticide composition. The composition comprises an effective component A and an effective component B, the effective component A is hydroxychloroquine, and the effective component B is azoxystrobin, phenazine-1-carboxylic acid or eugenol. According to the composition, the hydroxychloroquine, the azoxystrobin, the phenazine-1-carboxylic acid or the eugenol are taken as effective components for compounding, so that the composition has an obvious synergistic effect on preventing and treating the tea leaf spot disease, the tea tree anthracnose and the botrytis cinerea, and the generation of the drug resistance and the drug resistance of plants can be delayed by compounding the effective components; more choices are provided for prevention and treatment of pathogenic fungi, and the bacillus subtilis has a wide application prospect in prevention and treatment of plant pathogenic fungi diseases.

Description

Technical Field

[0001] The invention belongs to the technical field of pesticides, and particularly relates to a hydroxychloroquine compound pesticide composition for preventing and controlling plant pathogenic fungi and an application thereof. Background Art

[0002] Fungi are heterotrophic organisms with nuclei, filamentous vegetative bodies, spore production, no chlorophyll, and nutrients absorbed by absorption. Some can live parasitically on plants. Fungi are a large group that is extremely widely distributed in nature. Currently, 87,861 species have been found, of which more than 10,000 species can cause plant diseases, making them the most important group of plant pathogens. Plant fungal diseases caused by fungal infection account for about 70% to 80% of the total number of plant diseases. They can pose a major threat and disaster to ecological security, food security, and biodiversity.

[0003] Hydroxychloroquine (Hydroxychloroquine, structural formula Figure 1(shown in Figure 2) is a 4-aminoquinoline derivative antimalarial drug with similar effects and mechanisms to chloroquine, but only half as toxic as chloroquine. Hydroxychloroquine has anti-inflammatory, immune-modulating, and anti-infective effects. Bioinformatics and medicinal chemistry and biology studies on 15 selected potential targets of SARS-CoV-2 and 6 FDA drugs (chloroquine, hydroxychloroquine, favipiravir, lopinavir, remdesivir, and ritonavir) showed that hydroxychloroquine also has antiviral potential (Sinosh, S., Dharshini, G., et al. Structural and molecular basis of the interaction mechanism of selected drugs towards multiple targets of SARS-CoV-2 by molecular docking and dynamic simulation studies-deciphering the scope of repurposed drugs. Computers in Biology and Medicine, 2020, 55: 105960). The evaluation of the efficacy and safety of hydroxychloroquine in the treatment of COVID-19 infected patients found that hydroxychloroquine may help reduce the progression of lung lesions (Phulen, S., Hardeep, K., et al. Virological and clinical cure in COVID-19 patients treated with hydroxychloroquine: a systematic review and meta-analysis. Journal of Medical Virology, 2020, 92: 776.0-785.0). Hydroxychloroquine is also commonly used in the prevention and treatment of skin infections, often in combination with other antibiotics.

[0004] Azoxystrobin, chemical name is (E)-2-{2-[6(2-cyanophenoxy)pyrimidin-4-yloxy]phenyl}-3-methoxyacrylate, chemical formula is C 22 H 17 N3O5 (structural formula Figure 2As shown), it is a methoxyacrylate fungicide. Azoxystrobin belongs to the QoI fungicide, which inhibits mitochondrial respiration by blocking cytochrome c reductase. It has high efficiency and broad-spectrum antibacterial activity, and shows good antibacterial activity against diseases caused by almost all fungi (Ascomycota, Basidiomycota, Mastochorycetes and Deuteromycota), such as powdery mildew, rust, glume blight, web spot, downy mildew, rice blast and other diseases. It can be used for stem and leaf spraying, seed treatment, and soil treatment. It is mainly used to prevent and control plant diseases such as cereals, rice, peanuts, grapes, potatoes, fruit trees, vegetables, coffee, and lawns. QoI fungicides are characterized by a very high risk of resistance, which interferes with their biological activity (Balandzic, M., Stojsin, V., et al. Sensitivity of Cercospora Beticola isolates to azoxystrobin. Contemporary Agriculture, 2020, 69: 1-4.). Azoxystrobin has short-term developmental effects on juvenile and adult zebrafish, can lead to mitochondrial dysfunction in juvenile and adult zebrafish, causes oxidative stress in juvenile and adult zebrafish, induces apoptosis in juvenile zebrafish, but has no effect on adult zebrafish. It can activate the autoimmune response of juvenile and adult zebrafish (Fang, JC, Pei, ZW, et al. Short-term developmental effects and potential mechanisms of azoxystrobin in larval and adult zebrafish (Danio rerio). Aquatic Toxicology, 2018, 198: 129-140).

[0005] The chemical formula of phenazine-1-carboxylic acid (PCA) is C 13 H8N2O2 (structural formula Figure 3), the molecular weight is 246.1966. P.chlororaphis 30–84 can produce phenazine-1-carboxylic acid (PCA), 2-hydroxy-phenazine-1-carboxylic acid (2OH-PCA) and 2-hydroxy-phenazine (2-OHPZ), and the monooxygenase encoded by the phzO gene can convert PCA into 2OH-PCA in small amounts (Pierson, LS, Thomashow, LS Cloning and heterologous expression of the phenazine biosynthetic locus from Pseudomonas aureofaciens 30–84. Mol. Plant Microbe In, 1992, 5: 330-339). P.aeruginosa PAO1 and P.chlororaphis PCL1391 have the phzH gene, which is responsible for converting PCA into phenazine-1-carboxamide (PCN). Phenazines have a wide range of antibacterial activity against crop diseases. For example, PCA has strong antibacterial activity against Alternaria alternata, Botrytis cinerea, Fusarium oxysporum f.sp.radicis-lycopersici, Fusarium oxysporum f.sp.ciceris, Pythium splendens, Gaeumannomyces graminis var.tritici, Mycosphaerallamelonis, Phellinus noxius, Pythium spp. and Phytophthora infestans. PCA has a 70% efficacy against watermelon wilt and sweet pepper blight, and an 80% efficacy against melon vine blight (Xu Yuquan. Green microbial antibacterial agent shenqinmycin M18. Fine and Specialty Chemicals, 2005, 12: 8-9).

[0006] Eugenol, chemical name 4-allyl-2-methoxyphenol, chemical formula C 10 H 12 O2 (structural formula Figure 4It is a plant essential oil, a colorless to light yellow liquid, slightly soluble in water, soluble in organic solvents such as ethanol, acetone, ethyl acetate, ether, and chloroform. It is mainly used as the main fragrance agent for the preparation of cloves, carnations, carnations and other flavors, and can also be used as a food flavor, as well as an insecticide and preservative (Anna, M., Ramona, B., et al. Antimicrobial activity of eugenol and essential oils containing eugenol: a mechanistic viewpoint. Critical Reviews in Microbiology, 2017, 43: 668-689). Eugenol has antibacterial activity, therapeutic effects on diabetes, and inhibits cholinesterase activity (Hayriye, GB, Ali, K., et al. Novel eugenol bearing oxypropanolamines: synthesis, characterization, antibacterial, antidiabetic, and anticholinergic potentials. Bioorganic Chemistry, 2019, 88: 102931-102931).

[0007] Studies have found that long-term, continuous, and single application of a fungicide active ingredient can easily lead to drug resistance in pathogens. Reasonable mixing of pesticides has many advantages, such as improving prevention efficiency, delaying the development of drug resistance in pathogens, reducing drug costs, and expanding the fungicide spectrum. Given that hydroxychloroquine has the effect of treating skin fungal infections in medicine, there is currently no use of hydroxychloroquine in the agricultural field. This study compounded hydroxychloroquine with myclobutanil, phenazine-1-carboxylic acid, and eugenol, and measured their activity against plant pathogenic fungi, in order to lay the foundation for the development of crop fungicides. Summary of the invention

[0008] In view of this, one of the objects of the present invention is to provide a hydroxychloroquine compound pesticide composition for controlling plant pathogenic fungi, the composition comprising an active ingredient A and an active ingredient B, the active ingredient A being hydroxychloroquine, and the active ingredient B being azoxystrobin, phenazine-1-carboxylic acid or eugenol.

[0009] Preferably, the mass ratio of active ingredient A to active ingredient B is 1:1, 1:2 or 2:1.

[0010] Preferably, the above composition is prepared in the form of a suspension or water dispersible granules. The above effective ingredients can be prepared into different dosage forms by adding auxiliary agents known to those skilled in the art.

[0011] The second object of the present invention is to provide a method for preparing the above-mentioned composition, comprising the following steps:

[0012] 1) Weigh 0.012 g of hydroxychloroquine and dissolve it in DMSO (dimethyl sulfoxide) to prepare a mother solution I with a hydroxychloroquine concentration of 100 mg / mL; weigh azoxystrobin, phenazine-1-carboxylic acid or eugenol and dissolve it in DMSO to prepare a mother solution II with a concentration of 100 mg / mL;

[0013] 2) Mix the mother solution I and the mother solution II in proportion for compounding.

[0014] The third object of the present invention is to provide the use of the above composition in inhibiting diseases caused by plant pathogenic fungi.

[0015] Preferably, the plant pathogenic fungi include any one or more of Botrytis cinerea, Lasiodiplodia theobromae, Didymella segeticola and Glomerella cingulata.

[0016] The bactericidal composition of hydroxychloroquine and azoxystrobin, hydroxychloroquine and phenazine-1-carboxylic acid, and hydroxychloroquine and eugenol of the present invention has a synergistic effect and is safe and environmentally friendly, and is used to prevent and treat common plant diseases such as tea leaf spot, tea tree anthracnose, and tomato gray mold; compared with existing control agents, it achieves the purpose of improving drug efficacy, reducing pollution, and reducing costs. The compound pesticide composition of the present invention has a strong synergistic effect; the active ingredient has a unique mode of action and has no cross-resistance with existing bactericides; the dosage form is advanced and environmentally friendly, with little pollution to the environment, and no organic components are added to the preparation; it has fast rapid effect and a long lasting effect, and has broad application prospects in the prevention and treatment of plant pathogenic fungal diseases. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 is the structural formula of hydroxychloroquine;

[0018] Figure 2 The structural formula of azoxystrobin;

[0019] Figure 3 is the structural formula of phenazine-1-carboxylic acid;

[0020] Figure 4 It is the structural formula of eugenol;

[0021] Figure 5 The antibacterial activity of 1:1 combination of hydroxychloroquine and azoxystrobin inoculated with Didymella segeticola hyphae after treatment for 48 hours, scale bar = 1 cm;

[0022] Figure 6The antibacterial activity of 1:2 combination of hydroxychloroquine and azoxystrobin inoculated with Didymella segeticola hyphae after treatment for 48 hours, scale bar = 1 cm;

[0023] Figure 7 The antibacterial activity of 2:1 combination of hydroxychloroquine and azoxystrobin inoculated with Didymella segeticola hyphae after treatment for 48 hours, scale bar = 1 cm;

[0024] Figure 8 Schematic diagram of the living lesion area and inhibition rate of different ratios of hydroxychloroquine and myclobutanil combination on Didymella segeticola mycelium 48 hours after inoculation.

[0025] Fig. 9 The antibacterial activity of 1:1 combination of hydroxychloroquine and phenazine-1-carboxylic acid inoculated with Glomerella cingulata mycelium after treatment for 48 hours, scale bar = 1 cm;

[0026] Fig.10 The antibacterial activity of 1:2 combination of hydroxychloroquine and phenazine-1-carboxylic acid inoculated with Glomerella cingulate hyphae after treatment for 48 hours, scale bar = 1 cm;

[0027] Fig.11 The antibacterial activity of 2:1 combination of hydroxychloroquine and phenazine-1-carboxylic acid inoculated with Glomerella cingulata mycelium after treatment for 48 hours, scale bar = 1 cm;

[0028] Fig.12 Schematic diagram of the live lesion area and inhibition rate after the mycelium was inoculated with Glomerella cingulata and treated for 48 hours with different ratios of hydroxychloroquine and phenazine-1-carboxylic acid.

[0029] Fig.13 The antibacterial activity of 1:1 combination of hydroxychloroquine and eugenol inoculated with Botrytis cinerea mycelium after treatment for 48 hours, scale bar = 1 cm;

[0030] Fig.14 The antibacterial activity of 1:2 combination of hydroxychloroquine and eugenol inoculated with Botrytis cinerea mycelium after treatment for 48 hours, scale bar = 1 cm;

[0031] Fig.15 The antibacterial activity of hydroxychloroquine and eugenol in a ratio of 2:1 after inoculation with Botrytis cinerea mycelium for 48 hours, scale bar = 1 cm;

[0032] Fig.16Schematic diagram of the living lesion area and inhibition rate after 48 hours of inoculation with Botrytis cinerea mycelium in different ratios of hydroxychloroquine and eugenol. DETAILED DESCRIPTION

[0033] The present invention will be described in detail below in conjunction with examples, which are only illustrative and are not intended to limit the scope of application of the present invention. The present invention is not limited to the following embodiments or examples, and any modifications and variations that do not violate the spirit of the present invention should be included within the scope of the present invention. The experimental materials used in the following examples are commercially available unless otherwise specified; the percentages mentioned in the following examples are all mass percentages unless otherwise specified.

[0034] In order to determine the synergistic effect of the combination of hydroxychloroquine and azoxystrobin, hydroxychloroquine and phenazine-1-carboxylic acid, and hydroxychloroquine and eugenol, these two ingredients were first used for indoor bioassays. After analyzing the characteristics of the two active ingredients, the bioassay objects were set as plant pathogenic fungi D. segeticola (strain number: GZSQ-4, deposit number: CGMCC3.20152), L. theobromae (strain number: GZHS-2017-010, deposit number: CGMCC3.20151), G. cingulata (deposit number: ACCC 35058) and B. cinerea (strain number: GZFQ-1, deposit number: CGMCC3.20932) for the following specific experiments. Among them, D. segeticola belongs to the genus Subspora and can cause tea leaf spot disease. L. theobromae belongs to the genus Lactodiporus and can cause tea leaf spot disease. Causes diseases such as bud dieback, wilt and stem blight, root rot, stem rot, fruit rot, etc. in various hosts in tropical and subtropical regions. Host plants include guava, coconut, papaya and grapes. G. cingulata, belonging to the class Pestozoales, Pestozoaceae, can cause anthracnose in tea trees and apples. B. cinerea belongs to the genus Botrytis and can cause gray mold in vegetables and grapes.

[0035] Experimental Example 1 Toxicity Test

[0036] Indoor bioassay experimental method was used: referring to standard NY / T1156.7-2006, the growth rate method was used to determine the inhibitory effect of the agent on the mycelial growth of tea leaf spot, tea anthracnose and gray mold pathogens.

[0037] (1) Preparation of medicines

[0038] 1) Weigh 0.102 g of hydroxychloroquine original drug (98%) (purchased from Aladdin Reagent (Shanghai) Co., Ltd.) and dissolve it in 1 mL of DMSO to prepare a 100 mg / L stock solution.

[0039] 2) Weigh 0.102 g of azoxystrobin technical drug (98%) (purchased from Aladdin Reagent (Shanghai) Co., Ltd.) and dissolve it in 1 mL of DMSO to prepare a 100 mg / L stock solution.

[0040] 3) Weigh 0.102 g of phenazine-1-carboxylic acid technical drug (98%) (purchased from Shanghai MacLean Biochemical Technology Co., Ltd.) and dissolve it in 1 mL of DMSO to prepare a 100 mg / L stock solution.

[0041] 4) Weigh 0.102 g of eugenol technical (98%) (purchased from Shanghai MacLean Biochemical Technology Co., Ltd.) and dissolve it in 1 mL of DMSO to prepare a 100 mg / L stock solution.

[0042] 5) Compounding: Hydroxychloroquine was compounded with azoxystrobin, phenazine-1-carboxylic acid and eugenol respectively, and the compounding ratios were set to 1:1, 1:2 and 2:1, and the above mother solutions were configured according to the ratios to obtain compound agents of various ratios.

[0043] (2) Laboratory testing of single and mixed doses of hydroxychloroquine with azoxystrobin, phenazine-1-carboxylic acid, and eugenol

[0044] On the basis of preliminary experiments, four concentrations were designed from the range of 10% to 90% inhibition rate of mycelial growth of each agent. Each agent (single agent and compound agent) was added to the PDA medium that had been melted and cooled to room temperature to make the final concentrations of 25 μg / mL, 50 μg / mL, 100 μg / mL and 200 μg / mL. After being fully shaken, the medium was poured into a sterilized culture dish (90 mm) to prepare a drug-coated plate. Each treatment was repeated 4 times. The treatment with sterile water was used as a blank control. L. theobromae, D. segeticola, G. cingulata and B. cinerea were picked with a sterile hole puncher (4 mm). The mycelial surface was aseptically inoculated in the center of the drug-coated plate with the mycelium facing down. The plate was inverted in a constant temperature incubator at 25°C for culture. After 3-9 days of culture, the colony diameter was measured by the cross method. The inhibition rate was calculated according to formula (1). Then, DPS v was used to calculate the inhibition rate. 9.01 software (http: / / www.dpsw.cn / dps_eng / ) to calculate the regression equation and r 2 ,EC 50 The regression equation represents the relationship between mycelial growth rate and the dosage of the agent; EC 50 represents the median effective concentration.

[0045]

[0046] The Wadley method was used to evaluate the biological activity of the mixture of A and B, and the SR (synergistic ratio) was calculated according to formulas (2) and (3).

[0047]

[0048] Where: a, b is the ratio of single agent A and single agent B in the compound; EC(A) 50 、EC(B) 50 The EC of A and B are 50 Measured value; EC 50(th) EC for compound preparation 50 Theoretical value.

[0049]

[0050] SR represents the interaction between A and B after mixing: EC 50(ob) Indicates EC after compounding 50 Measured value. SR>1.5 indicates synergistic effect, 0.5≤SR≤1.5 indicates additive effect, and SR<0.5 indicates antagonistic effect.

[0051] The results are shown in Tables 1-7.

[0052] Table 1 The results of toxicity test of hydroxychloroquine against tea leaf spot, tea tree anthracnose and tomato gray mold

[0053]

[0054] Table 2 The results of toxicity test of azoxystrobin against tea leaf spot, tea anthracnose and tomato gray mold

[0055]

[0056]

[0057] Table 3 Results of toxicity test of phenazine-1-carboxylic acid against tea leaf spot, tea anthracnose and tomato gray mold

[0058]

[0059] Table 4 The results of toxicity test of eugenol against tea leaf spot, tea anthracnose and tomato gray mold

[0060]

[0061] Table 5 The toxicity test results of different ratios of hydroxychloroquine and azoxystrobin against tea leaf spot, tea anthracnose and tomato gray mold

[0062]

[0063] Table 6 The results of toxicity test of different ratios of hydroxychloroquine and phenazine-1-carboxylic acid against tea leaf spot, tea anthracnose and tomato gray mold

[0064]

[0065]

[0066] Table 7 The results of toxicity test of different ratios of hydroxychloroquine and eugenol against tea leaf spot, tea anthracnose and tomato gray mold

[0067]

[0068] Analysis of the above data shows that when hydroxychloroquine and azoxystrobin, hydroxychloroquine and phenazine-1-carboxylic acid, and hydroxychloroquine and eugenol are compounded in different ratios, the synergistic ratio (SR) of the formula is greater than 0.5, and different proportions of synergistic effects are respectively achieved on the prevention and control of tea leaf spot, tea tree anthracnose, and tomato gray mold. Among them, the compounding of hydroxychloroquine and azoxystrobin has a synergistic effect on L. theobromae and G. cingulata, and has an additive effect on D. segeticola except for 1:1 and B. cinerea except for 2:1, which is an additive effect, and the rest are synergistic, that is, the 1:2 compounding agent of hydroxychloroquine and azoxystrobin has an inhibitory synergistic effect on all fungi. For the combination of hydroxychloroquine and phenazine-1-carboxylic acid, it has a synergistic effect on L. theobromae and G. cingulata, and the synergistic ratio is greater than 4, which is a very strong effect. It has an additive effect on D. segeticola, 2:1 has a synergistic effect on B. cinerea, and 1:1 and 1:2 have an additive effect. For hydroxychloroquine and eugenol, 2:1 has a synergistic effect on D. segeticola, 1:2 and 2:1 have a synergistic effect on B. cinerea, and the rest have an additive effect. It can be seen that the compound preparation of hydroxychloroquine with azoxystrobin, phenazine-1-carboxylic acid, and eugenol can become an ideal agent for prevention and treatment.

[0069] Through indoor in vitro experiments, it was determined that hydroxychloroquine can have a good synergistic effect when combined with several active ingredients such as myclobutanil, phenazine-1-carboxylic acid, and eugenol.

[0070] Experimental Example 2 Indoor in vivo test

[0071] According to the above indoor SR values, indoor in vivo tests were carried out on the composite compositions of hydroxychloroquine, myclobutanil, phenazine-1-carboxylic acid and eugenol for preventing and controlling tea leaf spot D.segeticola, tea tree anthracnose G.cingulata and tomato gray mold B.cinerea to determine the effects of the formula on preventing and controlling tea leaf spot D.segeticola, tea tree anthracnose G.cingulata and tomato gray mold B.cinerea.

[0072] (1) Antibacterial activity of hydroxychloroquine and azoxystrobin against D. segeticola in vivo

[0073] The tea tree variety used was Fuding Dabaicha (Camellia sinensis (L.) O. Kuntze), the tea tree age was 3 years, and the tea tree age was 30 days. Five replicates were set for each treatment group. The second or third leaf of the tea tree was selected, and the front and back of the leaf were wiped clean with moistened sterilized cotton and the surface moisture was naturally dried. 100, 200, 400, 800, 1 600, 3 200, 6 400 μg / mL hydroxychloroquine and azoxystrobin compound solutions were prepared. The leaves were sprayed and treated. After the liquid on the surface of the leaves was naturally dried, small holes were made in four corners on both sides of the leaves with a syringe. Then, a sterilized 4 mm diameter puncher was used to punch a fresh D. segeticola colony that had been cultured for 8 days, and then the punched cake was inoculated on the punctured part of the leaf surface with mycelium facing downward. The negative control group was inoculated with sterile PDA medium, and the positive control group was sprayed with sterile water. After 48 hours, the pathogenicity was observed and photographed.

[0074] (2) Antibacterial activity of the combination of hydroxychloroquine and phenazine-1-carboxylic acid against (G. cingulata) in vivo

[0075] The tea tree variety used was Fuding Dabaicha (Camellia sinensis (L.) O. Kuntze), with a tree age of 3 years and a tea leaf age of 30 days. Five replicates were set for each treatment group. The second or third leaf of the tea tree was selected, and the front and back of the leaf were wiped clean with moist sterilized cotton and the surface moisture was naturally dried. 100, 200, 400, 800, 1 600, and 3 200 μg / mL of hydroxychloroquine and phenazine-1-carboxylic acid compound solutions were prepared. The leaves were sprayed for treatment. After the liquid on the surface of the leaves was naturally dried, a syringe was used to punch small holes in four corners on both sides of the leaves. Then, a sterilized (4 mm) diameter puncher was used to punch a bacterial cake on a fresh G. cingulata colony that had been cultured for 7 days, and then the punched bacterial cake was inoculated on the front puncture of the leaf with the hyphae facing down. Among them, the sterile PDA medium was used for inoculation as the negative control group, and the sterile water was used for spraying as the positive control group. After 48 hours, observe and take photos of the pathogenic conditions.

[0076] (3) Antibacterial activity of the combination of hydroxychloroquine and eugenol against B. cinerea in vivo

[0077] Tomato fruit varieties were collected from a plantation in Guizhou and transported back to the laboratory. Fruits of uniform size and full color were selected. The fruits were wiped clean with moist sterilized cotton and the surface moisture was naturally dried. Each treatment group was set up with 5 replicates. 200, 400, 800, 1 600, 3 200, 6 400 μg / mL hydroxychloroquine and eugenol compound solutions were prepared. The fruits were sprayed and treated. After the liquid on the surface of the fruit was naturally dried, a syringe was used to punch small holes in the shape of four corners on the fruit. Then, a sterilized (4mm) diameter puncher was used to punch a bacterial cake on a fresh B. cinerea colony that had been cultured for 3 days, and then the beaten bacterial cake was inoculated with the puncture site on the front of the fruit facing down. Among them, sterile PDA medium was used for inoculation as a negative control group, and sterile water was used for spraying as a positive control group. After 48 hours, the pathogenicity was observed and photographed.

[0078] The results are shown in Table 8.

[0079] Disease index = lesion area

[0080] Control effect % = [(control condition - treatment condition) / control condition] * 100

[0081] Table 8 Results of indoor in vivo efficacy test on the prevention and treatment of pathogenic fungi

[0082]

[0083]

[0084]

[0085] The results are as follows:

[0086] Depend on Figure 5-7 As shown, after spraying the combination of hydroxychloroquine and azoxystrobin at a ratio of 1:1 (A1-I1), 1:2 (A2-I2), and 2:1 (A3-I3), as the concentration of the drug increased, the inhibition rate of the pathogen D. segeticola lesions showed an upward trend (A: CK (after spraying water, connected to blank PDA), B: CK (no spraying, the bacteria caused disease), C: 100μg / mL compound solution spraying, D: 200μg / mL compound solution spraying, E: 400μg / mL compound solution spraying, F: 800μg / mL compound solution spraying, G: 1600μg / mL compound solution spraying, H: 3200μg / mL compound solution spraying, I: 6400μg / mL compound solution spraying, the bacteria caused disease for 48h). Figure 8(The horizontal axis represents the concentration of hydroxychloroquine and myclobutanil after compounding, and the vertical axis represents the lesion area and inhibition rate of hydroxychloroquine and myclobutanil after compounding on tea leaves inoculated with D. segeticola) as shown, after spraying the compound combination of hydroxychloroquine and myclobutanil, as the drug concentration increases, the lesion area of ​​the pathogen D. segeticola shows a downward trend, and the inhibition rate of the lesions shows an upward trend.

[0087] Depend on Figure 9-11 As shown, after spraying the combination of hydroxychloroquine and phenazine-1-carboxylic acid at a ratio of 1:1 (A1-H1), 1:2 (A2-H2), and 2:1 (A3-H3), the inhibition rate of the pathogen G. cingulata lesions showed an upward trend with the increase of the drug concentration (A: CK (after spraying water, connected with blank PDA), B: CK (no spraying, the bacteria caused disease), C: 100μg / mL compound solution spraying, D: 200μg / mL compound solution spraying, E: 400μg / mL compound solution spraying, F: 800μg / mL compound solution spraying, G: 1600μg / mL compound solution spraying, H: 3200μg / mL compound solution spraying, the bacteria caused disease for 48h). Fig.12 (The horizontal axis represents the concentration of hydroxychloroquine and phenazine-1-carboxylic acid after compounding, and the vertical axis represents the lesion area and inhibition rate of hydroxychloroquine and phenazine-1-carboxylic acid after compounding on tea leaves inoculated with G. cingulata) as shown, after spraying the compound combination of hydroxychloroquine and phenazine-1-carboxylic acid, as the concentration of the added drug increases, the lesion area of ​​the pathogen G. cingulata shows a downward trend, and the inhibition rate of the lesions shows an upward trend.

[0088] Depend on Figure 13-15 As shown, after spraying the combination of hydroxychloroquine and eugenol at a ratio of 1:1 (A1-H1), 1:2 (A2-H2), and 2:1 (A3-H3), as the concentration of the drug increased, the inhibition rate of the pathogen B. cinerea lesions showed an upward trend (A: CK (after spraying water, connected to blank PDA), B: CK (no spraying, the bacteria caused disease), C: 200μg / mL compound solution spraying, D: 400μg / mL compound solution spraying, E: 800μg / mL compound solution spraying, F: 1600μg / mL compound solution spraying, G: 3200μg / mL compound solution spraying, H: 6400μg / mL compound solution spraying, the bacteria caused disease for 48h). Fig.16 (The horizontal axis represents the concentration of hydroxychloroquine and eugenol after compounding, and the vertical axis represents the lesion area and inhibition rate of hydroxychloroquine and eugenol after compounding on tomato fruit after inoculation with B. cinerea) as shown, after spraying the compound combination of hydroxychloroquine and eugenol, with the increase of drug concentration, the lesion area of ​​the pathogen B. cinerea showed a downward trend, and the inhibition rate of the lesions showed an upward trend.

[0089] In summary, it is shown that the composition of hydroxychloroquine combined with azoxystrobin, phenazine-1-carboxylic acid and eugenol has an obvious preventive and therapeutic effect on the spread of pathogenic fungi. When the dosage of the active ingredients is the same, under the same concentration and the same treatment time, the preventive and therapeutic effect of the composition of hydroxychloroquine combined with azoxystrobin, phenazine-1-carboxylic acid and eugenol is higher than the effect of each agent used alone; at the same time, the combination of agents with two mechanisms of action is beneficial to delaying the drug resistance of plants. The formula discovered in this study has low cost and good environmental compatibility.

[0090] The conventional techniques and schemes not described in detail in the above embodiments are well known in the art, so they will not be described in detail here. The above embodiments and / or experimental examples describe the preferred embodiments of the present invention in detail, but the present invention is not limited to the specific details in the above embodiments. Within the scope of the technical concept of the present invention, the technical scheme of the present invention can be subjected to a variety of simple modifications, and these simple modifications all belong to the protection scope of the present invention.

Claims

1. A hydroxychloroquine compound pesticide composition for preventing and controlling plant pathogenic fungi, characterized in that: The composition comprises an active ingredient A and an active ingredient B, wherein the active ingredient A is hydroxychloroquine, and the active ingredient B is azoxystrobin, phenazine-1-carboxylic acid or eugenol.

2. The composition according to claim 1, characterized in that The mass ratio of active ingredient A to active ingredient B is 1:1, 1:2 or 2:

1.

3. A composition according to any one of claims 1 to 2, characterized in that The composition is prepared in the form of a suspension or water dispersible granules.

4. The method for preparing the composition according to any one of claims 1 to 3, characterized in that: The steps include: 1) weighing hydroxychloroquine and dissolving it in DMSO to prepare a mother solution I with a hydroxychloroquine concentration of 100 mg / mL; weighing azoxystrobin, phenazine-1-carboxylic acid or eugenol and dissolving it in DMSO to prepare a mother solution II with a concentration of 100 mg / mL; 2) Mix the mother solution I and the mother solution II in proportion for compounding.

5. Use of the composition according to any one of claims 1 to 3 in controlling plant pathogenic fungi.

6. The use according to claim 5, characterized in that The plant pathogenic fungi include any one or more of Botrytis cinerea, Lasiodiplodia theobromae, Didymella segeticola and Glomerella cingulata.

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