Cynanchum bungei root rot pathogen biological source pesticide compound composition

Abstract

The invention discloses a cynanchum bungei root rot pathogenic bacterium fusarium solani biological source pesticide compound composition for prevention and application of the cynanchum bungei root rot pathogenic bacterium fusarium solani biological source pesticide compound composition. The composition comprises a composition of two or more of cnidium lactone, pyrethrin and eugenol and nano drug-loading synergistic particles of the composition. Among 27 groups of pesticides compounded by three biological source pesticides according to different proportions, the cotoxicity coefficient of F.solani compounded by osthole and pyrethrin in a ratio of 2: 3 is the highest and is 139.87, the EC50 is 4.00 mg / L, and the combined toxicity shows a synergistic effect. The silicon dioxide microsphere (HMSN) loaded cnidium lactone and pyrethrin in a ratio of 2: 3 compounded agent CS-HMSN can significantly inhibit the growth of F.solani, alleviates the adverse effect of F.solani on coastal radix cynanchi bungei, and has an important application prospect.

Description

Technical Field

[0001] The invention relates to a traditional Chinese medicine pesticide preparation, in particular to a biological source pesticide compound composition for Radix Cynanchum multiflorum root rot pathogens. Background Art

[0002] Binhai Baishouwu is the dried root of Cynanchum auriculatum Royle ex Wight, a plant of the Apocynaceae family. It is a local specialty product with a geographical indication area and one of the famous authentic medicinal materials in Jiangsu Province. Binhai Baishouwu has been eaten in Binhai County, Jiangsu Province for hundreds of years. It has the effects of nourishing the kidney and liver, promoting hair growth, nourishing blood and essence, and anti-aging (Tang Junjie, Gu Wei, Qian Xudong, et al. Study on the medicinal value and resource assessment of Binhai Baishouwu, a local medicinal material in Jiangsu [J]. Journal of Nanjing University of Chinese Medicine, 2023, 39(08):794-800.). Modern research shows that C contained in Baishouwu 21Steroids and acetophenones are its most important active ingredients, which have multiple pharmacological values ​​such as anti-tumor, anti-inflammatory, lipid-lowering, immune-enhancing, liver-protecting, anti-aging, and antioxidant. The phenomenon of continuous cropping obstacles in Chinese medicinal materials is most common in rhizomes. After continuous cropping of Chinese medicinal materials, soil-borne diseases worsen, the physical and chemical properties of the soil and the diversity of microorganisms change, the growth of plants weakens, and the photosynthetic rate decreases, which in turn affects the physiological activities of the plants, and ultimately leads to a decrease in the yield and quality of medicinal materials. Binhai Baishouwu faces serious continuous cropping obstacles during the planting process. Continuously cropped Binhai Baishouwu often shows phenomena such as aggravated diseases and pests, reduced yields, and reduced quality, which seriously affects the development of Binhai Baishouwu industry. Shen M, Wu L, Zhang Y, et al. Leaf Litter from Cynanchumauriculatum Royle ex Wight Leads to Root Rot Outbreaks by Fusarium solani, Hindering Continuous Cropping[J]. FEMS Microbiology Ecology. 2024, 100(6): fiae068. et al. have shown that Fusarium solani is a potential factor causing continuous cropping problems in Cynanchumauriculatum. Chemical control is the main method for the prevention and control of diseases and pests of Chinese medicinal materials, but at present, cultivation is faced with the problems of pesticide abuse, unscientific application of pesticides, and excessive pesticide residues. It is urgent to carry out the research and development and application of pesticide alternative technologies and related products, screen safe and low-toxic control methods, and eliminate or reduce chemical pesticides from the source. Biopesticides are biodegradable, decompose quickly, and have little or no toxicity, and have been considered as ecological alternatives to chemical pesticides. However, biopesticides have the problem of poor efficacy and durability. Nanopesticides can use nanotechnology to reduce the particle size of the original pesticide, increase the specific surface area, and use nanocarriers to load the pesticide to improve the stability of the pesticide and extend the duration of the pesticide, providing a green and environmentally friendly alternative for pest control without harming nature. Summary of the invention

[0003] Purpose of the invention: The technical problem to be solved by the present invention is to overcome the shortcomings of the prior art. For the pathogen of root rot of Cynanchum multiflorum, Fusarium solani (F.Solani), the antibacterial activity of 8 kinds of biogenic pesticides was preliminarily screened, and biogenic pesticides with strong antibacterial activity were selected for compounding and synergistic research. The mycelium rate growth method was used to determine the indoor toxicity intensity of different compound combinations, in order to screen out a compound combination of biogenic pesticides with obvious synergistic effect, and the compound combination of biogenic pesticides was loaded with silica microspheres to construct a theoretical basis for biological control methods of root rot of Cynanchum multiflorum and sustainable development of the industry, so as to promote the healthy, efficient and sustainable development of the Cynanchum multiflorum industry in Binhai.

[0004] Technical solution: In order to achieve the above purpose, the technical solution adopted by the present invention is:

[0005] A biosource pesticide compound composition for pathogenic bacteria of Cynanchum multiflorum root rot comprises one or more of osthole, pyrethrin, eugenol, berberine, physophanol methyl ether, matrine, kasugamycin and allicin emulsifiable concentrate.

[0006] As a preferred embodiment, the above-mentioned biological source pesticide compound composition for the pathogenic bacteria of Cynanchum multiflorum root rot includes a combination of two or more of osthole, pyrethrin and eugenol.

[0007] As a preferred embodiment, the above-mentioned biological source pesticide composite composition for the pathogenic bacteria of Cynanchum multiflorum root rot is a composition of osthole and pyrethrin in a mass ratio of 1:0.2-1.

[0008] As a more preferred embodiment, the above-mentioned biological source pesticide composite composition for the pathogenic bacteria of Cynanchum multiflorum root rot is a composition of osthole and pyrethrin in a mass ratio of 1:0.275.

[0009] The composite composition provided by the invention is used in preparing a pesticide preparation for resisting the pathogen of Radix Cynoglossi root rot, wherein the pathogen of Radix Cynoglossi root rot is Fusarium solani.

[0010] The invention discloses a biogenic pesticide silica microsphere for resisting the pathogenic bacteria of Radix Cynanchum multiflorum root rot. The silica microsphere is prepared by loading osthole and pyrethrin on the silica microsphere.

[0011] As a preferred embodiment, the above-mentioned silica microspheres of biogenic pesticide against the pathogenic bacteria of Cynanchum multiflorum root rot are prepared by loading osthole and pyrethrin in a conversion mass ratio of 1:0.275 on the silica microspheres.

[0012] The method for preparing silica microspheres of the present invention is characterized by comprising the following steps:

[0013] 0.3g hexadecyltrimethylammonium bromide (CTAB) was dispersed in 60ml anhydrous ethanol and 100ml deionized water, stirred magnetically, concentrated ammonia was added to make the pH 8-9, 2ml tetraethyl orthosilicate (TEO) was added dropwise, and the mixture was reacted at room temperature for 6h. The mixture was washed with deionized water and anhydrous ethanol for 3 times, centrifuged, and the precipitate was dispersed in a mixed solution of 60ml deionized water, 60ml anhydrous ethanol and 9ml cyclohexane, and sealed and placed at 60℃ for 3d. Filtered, the precipitate was washed with deionized water, precooled in a refrigerator at -80℃, and freeze-dried. The mixture was calcined at 550℃ in a muffle furnace for 6h and stored at room temperature to obtain HMSN.

[0014] Beneficial effects: The biosource pesticide composite composition for the pathogenic bacteria of Radix Cynanchum multiflorum root rot provided by the present invention has the following advantages compared with the prior art:

[0015] The present invention uses 8 kinds of bio-source pesticides such as osthole, kasugamycin, allicin emulsifiable concentrate, pyrethrin, and matrine to inhibit the bacterial growth rate and EC of the pathogenic bacteria F. Solani of the root rot of Cynanchum multiflorum. 50 Screening was carried out, and the biopesticides with good antibacterial effects were compounded, and the EC values ​​of the compound combinations with different proportions were determined. 50 The results showed that pyrethrin, eugenol and osthole were more sensitive to F.Solani, and EC 50 2.00mg / L, EC 50 9.49mg / L, 10.90mg / L, and subsequent compounding experiments were carried out; while berberine, physaccharin methyl ether EC 50 The concentrations of matrine, kasugamycin and allicin EC were all less than 100 mg / L, 29.61 and 53.86 mg / L respectively, and the antibacterial activity was slightly lower. Matrine, kasugamycin and allicin EC had poor inhibitory effects on F.Solani. 50 The concentrations of pyrethrins in the toxicity test were 101.22, 169.81, and 1037.33 mg / L, respectively. Pyrethrins are commonly used as highly effective, low-toxic, and low-residue insecticides, but there are few reports on their effects on fungal pathogens. This study found that pyrethrins had a good antibacterial effect on F. Solani, the pathogen of Cynanchum multiflorum root rot, in indoor toxicity tests, indicating that pyrethrins may have the potential to be used as a fungicide in agricultural production.

[0016] The results of the compounding experiment of bio-source pesticides in the present invention show that the compounding effect of osthole and pyrethrin in different proportions is generally better than that of osthole and eugenol, eugenol and pyrethrin compounding agents. There is no obvious trend in the compounding of osthole and eugenol in different proportions. Eugenol and pyrethrin are compounded in different proportions, EC 50 With the increase of eugenol dosage, the combined toxicity strength decreased, indicating that the overall strength of the combined toxicity increased with the increase of eugenol in the combination, proving that eugenol plays a major antibacterial role in the combined agent. 50 The combined toxicity increased with the decrease of the proportion of pyrethrin in the compound, but with the decrease of the proportion of pyrethrin in the compound, the combined toxicity first increased and then decreased, indicating that the higher and lower proportions of pyrethrin in the compound could not produce a good combined toxicity. The volume ratio of osthole (10.9 mg / L): pyrethrin (2.00 mg / L) was 2:3, and the maximum co-toxicity coefficient of the compound was 139.87, which had a synergistic effect and strong inhibitory activity. 50The concentration of pyrethrin is 4.00 mg / L. Since pyrethrin is easily decomposed and inactivated and is relatively expensive, compounding with osthole can reduce the dosage of pyrethrin, increase the duration of effectiveness, expand the control spectrum, and reduce production costs.

[0017] Nanomaterials have been widely used in plant protection due to their small size and high specific surface area. The range of materials used to manufacture nanoparticles is very wide. Nano-silicon dioxide can be used as a controlled-release water-soluble pesticide, which can make chemical substances properly absorbed by plants and deliver pesticides efficiently and persistently. The present invention uses silica microspheres (HMSN) to load osthole and pyrethrin compound agent CS to obtain the agent CS@HMSN, and evaluates the antibacterial effect of the agent through potted plant experiments. The study found that after one month of growth of the Cynanchum multiflorum plants, the F.solani group showed growth inhibition and root rot symptoms, while the Cynanchum multiflorum added with CS@HMSN grew well, and the indicators such as plant height, root length, root thickness, and fresh weight were significantly higher than those of the F.solani group, indicating that CS@HMSN has a good antibacterial effect and can significantly inhibit the adverse effects of F.solani on Cynanchum multiflorum. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 Scanning electron microscopy (A) and transmission electron microscopy (B) characterizations of HMSN.

[0019] Figure 2 The growth status of Cynanchum multiflorum under different treatments.

[0020] Figure 3 Effects of different treatments on the growth and development of Cynanchum multiflorum. Note: The bar graph represents the mean ± standard deviation of at least 10 replicates. Different letters indicate significant differences obtained by Duncan's multiple range test (p < 0.05). DETAILED DESCRIPTION

[0021] The present invention is further explained below in conjunction with specific embodiments. It should be understood that these embodiments are only used to illustrate the present invention and are not used to limit the scope of the present invention. After reading the present invention, various equivalent forms of modifications to the present invention by those skilled in the art all fall within the scope defined by the claims attached to this application.

[0022] Example 1

[0023] 1 Materials and methods

[0024] 1.1 Tested crops, strains and agents

[0025] 1.1.1 Pathogens of Cynanchum multiflorum root rot

[0026] Binhai Baishouwu is the dried tuberous root of Cynanchum auriculatum Royleex Wight, a plant of the genus Cynanchum in the Apocynaceae family. The pathogen of its root rot was collected from Binhai County, Yancheng City, Jiangsu Province in July 2023. After single spore isolation, combined with morphological and phylogenetic studies, the isolated pathogen was identified as Fusarium solani (F.solani), and its pathogenicity was verified based on indoor backgrafting.

[0027] 1.1.2 Pharmacy

[0028] The names and test concentrations of 8 biogenic pesticides and the positive control drug (CK1) are shown in Table 1.

[0029] Table 1 Tested biogenic pesticides and test concentrations

[0030] Pharmacy Dilution multiple <![CDATA[Use concentration / mg·L -1 > 1% Osthole 400、200、100、50、25 2.5、5、10、20、40 2% Kasugamycin 80、40、20、10、5 25、50、100、200、400 5% Allicin EC 160、80、40、20、10 31.25、62.5、125、250、500 1.5% Pyrethrins 1000、500、250、125、62.5 1.3、2.6、5.2、10.4、20.8 1.3% Matrine 400、200、100、50、25 3.25、6.5、13.0、26、52 0.5% berberine 160、80、40、20、10 3.125、6.25、12.5、25、50 0.3% Eugenol 160、80、40、20、10 1.875、3.75、7.5、15、30 0.5% Physcion 80、40、20、10、5 6.25、12.5、25、50、100 <![CDATA[50% carbendazim (CK1)]]> 10、5、2.5、1.25、0.625

[0031] Hexadecyltrimethylammonium bromide (CATB, 99%), Tianjin Guangfu Fine Chemical Research Institute; tetraethyl silicate (TEO, 98%), Shanghai Aladdin Biochemical Technology Co., Ltd.; ammonia (analytical grade 25%-28%), osthole (98%), Shanghai Yuanye Biotechnology Co., Ltd.; pyrethrin (30%), Shanghai Yuanye Biotechnology Co., Ltd.; acetonitrile (chromatographic grade), American Tiandi Co., Ltd.; anhydrous ethanol (analytical grade), Wuxi Yasheng Chemical Co., Ltd.

[0032] 1.1.3 Instruments

[0033] Clean bench, constant temperature incubator, high temperature steam sterilizer, electronic balance, pure water preparation instrument, electric blast drying oven, 1-10μL, 20-200μL, 100-1000μL pipettes, magnetic stirrer, freeze dryer, etc.

[0034] 1.2 Screening and compounding of F.solani biogenic fungicides

[0035] 1.2.1 Effects of biogenic fungicides on the mycelial growth of F. solani

[0036] The mycelium growth rate method was used to determine the inhibitory effects of 8 agents on pathogens. Different concentrations of agent stock solutions were prepared with sterile water, and diluted at different concentration multiples (Table 1). Then, they were mixed with PDA medium to prepare drug-containing medium. PDA medium without agents was used as a control. A 5mm diameter bacterial cake was punched at the edge of the colony with a hole puncher and inoculated on the surface of the PDA medium. The culture was cultured in an incubator at 28°C. Each group was repeated 3 times. The colony diameter was measured by the cross method 5 days after inoculation to calculate the inhibition rate. The data obtained were used to calculate the toxicity regression equation, EC 50 , R 2Eight kinds of biogenic pesticides were tested, carbendazim was used as the positive control (CK1), and the blank control was an equal amount of sterilized water (CK2). There were 10 treatments in total, each with 5 concentrations, and each concentration was repeated 3 times.

[0037] Inhibition rate (%) = (control colony diameter - treated colony diameter) / (control colony diameter - inoculated cake diameter) × 100.

[0038] 1.2.2 Combined toxicity test of biopesticides with good antibacterial activity

[0039] The reference method (SUN YP, Johnson ER. Analysis of Joint Action of Insecticides Against House Flies [J]. Journal of Economic Entomology, 1960, 53 (5): 887-892) and the method for screening the best synergistic formula of pesticide combination (Chen Li, Xu Hanhong, Li Yunyu, et al. Discussion on the screening method of the best synergistic formula of pesticide combination [J]. Journal of Plant Protection, 2000, (04): 349-354) were used to screen out the best ratio of the compound combination, and osthole (A), eugenol (B), and pyrethrin (C) with better antibacterial activity in 1.2.1 were selected. Three combinations were set up, namely osthole + eugenol (A + B), eugenol + pyrethrin (B + C), and osthole + pyrethrin (A + C). The EC of the single agent obtained in 1.2.1 50 Based on the concentration, the mixture was mixed in different proportions, and the ten equal points of the additive action line in the isobolite method were selected. A+B, B+C, and A+C were respectively compounded to set 9 ratios, a / 9b, a / 4b, 3a / 7b, 2a / 3b, a / b, 3a / 2b, 7a / 3b, 4a / b, and 9a / b. The volume ratios were 1:9, 1:4, 3:7, 2:3, 1:1, 3:2, 7:3, 4:1, and 9:1, and the concentration gradient of the compound was obtained. The linear regression equation was made for the dilution of biogenic pesticides with different ratios to different concentration gradients and their corresponding inhibition rates to calculate the EC of the compound. 50 The blank control was an equal amount of sterile water (CK3).

[0040]

[0041] When CTC≤80, it is an antagonistic effect, 80<CTC<120 is an additive effect, and when CTC≥120, it is a synergistic effect.

[0042] 1.3 CS@HMSN drug delivery enhancement experiment

[0043] 1.3.1 HMSN preparation

[0044] Hollow silica microspheres HMSN were prepared by soft film method (Li Yaping. Preparation of functional calixarene composite hollow mesoporous silica spheres and their removal of uranium (VI) in water [D]. University of South China, 2021.). Scanning electron microscopy SEM (Hitachi SU8010), transmission electron microscopy TEM (FEI-Talos F200S), particle size and ZETA potential (Malvern Zetasizer Pro) were performed.

[0045] 1.3.2 CS@HMSN drug delivery experiment

[0046] The compound with better effect obtained in 1.2.2 was prepared into a 5g / L liquid, ultrasonicated until completely dissolved, and heated in a water bath at 60℃ to obtain liquid CS. CS and HMSN were loaded with drugs, ultrasonically dispersed fully, sealed and stirred to fully mix, and then stirred in an open state until the organic solvent evaporated, washed, and centrifuged. Precooled at -80℃ for 24h, freeze-dried, and CS@HMSN was obtained. The drug loading was determined by high performance liquid chromatography.

[0047] 1.3.3 Potted plant experiment

[0048] To evaluate the control effect of CS@HMSN on F.solani, the pathogen of root rot of Cynanchum multiflorum, a pot experiment was conducted in an artificial climate chamber. Before sowing, Cynanchum multiflorum seeds were disinfected with 0.5% sodium hypochlorite solution, rinsed with sterile water, and planted in 100g sterile substrate. After growing for 1 month at 28℃ and relative humidity of 30%-70%, the biological control experiment was carried out. The Cynanchum multiflorum seedlings were divided into 6 treatment groups: blank group, treated with 40ml sterile water; F.solani group, treated with 20ml of 1×10 6 CFU of F.solani spore suspension and 20ml sterile water for root irrigation; carbendazim group, add 20ml F.solani spore suspension and 20ml 0.5mg / ml carbendazim suspension; CS@HMSN-1 group, add 20ml F.solani spore suspension and 20ml 0.025mg / ml CS@HMSN for root irrigation; CS@HMSN-2 group, add 20ml F.solani spore suspension and 20ml 0.05mg / ml CS@HMSN for root irrigation; CS@HMSN-3 group, add 20ml F.solani spore suspension and 20ml0.1mg / ml CS@HMSN for root irrigation. Each group was treated with 4 replicates, with at least 3 plants of B. multiflorum in each replicate, and observed after one month of cultivation.

[0049] 1.4 Data Processing

[0050] Excel, SPSS and Origin 2024 were used to perform statistical analysis of the data.

[0051] 2. Results and Analysis

[0052] 2.1 Effects of biogenic fungicides on the mycelial growth of F. solani

[0053] In this study, eight biogenic fungicides were selected to determine their inhibitory effects on F. solani. The results in Table 2 showed that F. solani was sensitive to osthole, pyrethrin, and eugenol, while EC 50 All of them were less than 20 mg / L, and all of them were less than the positive drug carbendazim (17.76 mg / L). Among them, pyrethrin had the best inhibitory effect on F. solani hyphae. 50 2.00mg / L; Eugenol is second, EC 50 9.49mg / L; Osthole EC 50 is 10.90mg / L; while berberine and physophanol methyl ether EC 50 The inhibitory effects of matrine, kasugamycin and allicin EC on F. solani were poor. 50 They are 101.22, 169.81 and 1037.33 mg / L.

[0054] Table 2 Inhibitory effect of biogenic fungicides on the mycelial growth of F. solani

[0055]

[0056]

[0057] 2. Inhibition rate and indoor toxicity of 23 biogenic fungicides against F. solani

[0058] From Tables 3, 4 and 5, it can be seen that, in general, the combination of osthole (A) and pyrethrin (C) is better than the combination of osthole (A) and eugenol (B) and eugenol (B) and pyrethrin (C). The combination of osthole (A) and pyrethrin (C) in Table 5 at a ratio of 3-4 (i.e., the volume ratio of the two is 4:6, which is converted to a mass ratio of 1:0.275) has the best inhibitory activity, EC 50 The total concentration of the 1-9, 2-8, 3-7, 5-5, 8-2, and 9-1 compound combinations had a total toxicity coefficient greater than 80, which showed an additive effect. The total toxicity coefficient of the 6-6 and 7-3 combinations was less than 80, and the compound agents had a certain antagonistic effect. This indicates that the 3-4 compound agent can be used as the optimal ratio for biological control of the pathogen of Cynanchum multiflorum root rot in the field.

[0059] Table 3 Toxicity regression equation and EC of the compound preparation of osthole (A) and eugenol (C) 50 , co-toxicity coefficient and combined toxicity

[0060]

[0061] Table 4 Toxicity regression equation and EC of eugenol (B) and pyrethrin (C) compound agents 50 , co-toxicity coefficient and combined toxicity

[0062]

[0063]

[0064] Table 5 Toxicity regression equation and EC of osthole (A) and pyrethrin (C) combination 50 , co-toxicity coefficient and combined toxicity

[0065]

[0066] Example 2

[0067] 1. A biogenic pesticide silica microsphere for resisting the pathogenic bacteria of Radix Cynanchum multiflorum root rot, prepared by loading osthole and pyrethrin in a mass ratio of 1:0.275 on the silica microsphere.

[0068] The preparation method of silica microspheres is as follows: 0.3g of hexadecyltrimethylammonium bromide (CTAB) is dispersed in 60ml of anhydrous ethanol and 100ml of deionized water, magnetically stirred, concentrated ammonia water is added to make the pH 8-9, 2ml of tetraethyl orthosilicate (TEO) is added dropwise, and the reaction is carried out at room temperature for 6h. The mixture is washed with deionized water and anhydrous ethanol for 3 times, centrifuged, and the precipitate is dispersed in a mixed solution of 60ml of deionized water, 60ml of anhydrous ethanol and 9ml of cyclohexane, and sealed and placed at 60℃ for 3d. Filter, wash the precipitate with deionized water, pre-cool in a refrigerator at -80℃, and freeze-dry. Calcine in a muffle furnace at 550℃ for 6h, and store at room temperature to obtain silica microspheres (HMSN).

[0069] The mass ratio of osthole and pyrethrin was 1:0.275, and the solution was prepared into 5g / L solution, and the solution was completely dissolved by ultrasonic treatment, and heated in a water bath at 60℃ to obtain the solution CS. The drug was loaded with CS and HMSN, and the solution was fully dispersed by ultrasonic treatment, and the mixture was fully mixed by sealed stirring, and then the solution was stirred in an open state until the organic solvent evaporated, washed, and centrifuged. The solution was precooled at -80℃ for 24h, and freeze-dried to obtain CS@HMSN.

[0070] 2. HMSN Characterization

[0071] Scanning electron microscopy and transmission electron microscopy observations ( Figure 1). HMSN is uniformly spherical, and has a certain hollow structure under transmission electron microscopy. The average particle size is 447±61nm, and the zeta potential is -49.40±1.25mV.

[0072] 3. Drug loading experiment

[0073] Using high performance liquid chromatography,

[0074] 4. Potted plant test

[0075] In order to evaluate the inhibitory effect of CS@HMSN on F.solani, the pathogen of root rot of Cynanchum multiflorum, a potted plant experiment was conducted, and 6 different treatment groups were set up. After one month of growth of Cynanchum multiflorum plants, the F.solani group showed significant growth inhibition and root rot symptoms, while the CS@HMSN group grew well. Figure 3 , the three different concentrations of CS@HMSN can inhibit F.solani, and the effects are better than carbendazim. Among the three concentrations, the plant height, number of leaves, root length, root thickness, fresh weight, leaf length, leaf width and other indicators of the CS@HMSN-2 group increased most significantly compared with the F.solani group, indicating that 0.05mg / ml CS@HMSN can significantly inhibit F.solani and alleviate the adverse effects of F.solani on Cynanchum multiflorum.

Claims

1. A biosource pesticide composite composition for the pathogenic bacteria of Radix Cynanchum multiflorum root rot, characterized in that: The composition comprises one or more of osthole, pyrethrin, eugenol, berberine, physophanol methyl ether, matrine, kasugamycin and allicin emulsifiable concentrate.

2. The biosource pesticide composite composition for the pathogenic bacteria of Radix Cynanchum multiflorum root rot according to claim 1, characterized in that: The composition comprises two or more of osthole, pyrethrin and eugenol.

3. The biosource pesticide composite composition for the pathogenic bacteria of Radix Cynanchum multiflorum root rot according to claim 1, characterized in that: The composition is a composition of osthole and pyrethrin in a mass ratio of 1:0.2-1.

4. The biosource pesticide composite composition for the pathogenic bacteria of Radix Cynanchum multiflorum root rot according to claim 3, characterized in that: The composition comprises osthole and pyrethrin in a mass ratio of 1:0.

275.

5. Use of the composite composition according to any one of claims 1 to 4 in the preparation of pesticide preparations for resisting pathogens of Cynanchum multiflorum root rot.

6. The use according to claim 5, characterized in that: The pathogen of Polygonum multiflorum root rot is Fusarium solani.

7. A biogenic pesticide against the pathogenic bacteria of Radix Cynanchum multiflorum root rot, characterized in that: Silica microspheres loaded with osthole and pyrethrin were prepared.

8. The silica microspheres as claimed in claim 7, which are biogenic pesticides against the pathogens of Cynanchum multiflorum root rot, are characterized in that: Silica microspheres loaded with osthole and pyrethrin in a mass ratio of 1:0.275 were prepared.

9. The method for preparing silica microspheres according to claim 7 or 8, characterized in that: The following steps are involved: Take hexadecyltrimethylammonium bromide and disperse it in anhydrous ethanol and deionized water, stir it magnetically, add concentrated ammonia water to make the pH value 8-9, add tetraethyl orthosilicate dropwise, react at room temperature, wash with deionized water and anhydrous ethanol, centrifuge, disperse the precipitate in a mixed solution of deionized water, anhydrous ethanol and cyclohexane, seal and place, filter by suction, wash the precipitate with deionized water, precool it in a refrigerator at -80℃, freeze-dry it, and then calcine it in a muffle furnace to obtain the product. The mass ratio of osthole and pyrethrin was 1:0.275, and the solution was prepared into 5g / L solution, and the solution was completely dissolved by ultrasonic treatment, and heated in a water bath at 60℃ to obtain the solution CS. The drug was loaded with CS and HMSN, and the solution was fully dispersed by ultrasonic treatment, and the mixture was fully mixed by sealed stirring, and then the solution was stirred in an open state until the organic solvent evaporated, washed, and centrifuged. The solution was precooled at -80℃ for 24h, and freeze-dried to obtain CS@HMSN.

10. Use of the silicon dioxide microspheres according to claim 7 or 8 in the preparation of pesticide preparations against pathogens of Cynanchum multiflorum root rot.

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