Antifungal biological coating agent for ornamental flower seeds and preparation method thereof

Abstract

The invention relates to the technical field of ornamental flower seeds, in particular to an antifungal biological coating agent for ornamental flower seeds and a preparation method thereof.The antifungal biological coating agent for ornamental flower seeds is prepared from, by weight, 1.5-3 g of polymer film-forming agent, 0.7-1.5 g of antibacterial polymer powder, 0.1-0.3 g of composite antifungal agent and the balance water, 2-5 g of an auxiliary agent, 90-95 g of an inorganic mineral filler and 0.5-1.5 g of a binder. The coating agent provided by the invention can realize multiple functions of disease prevention, growth promotion and water retention through one-time coating, reduces the labor and material cost of subsequent topdressing and pesticide spraying, and has a good application prospect.

Description

Technical Field

[0001] This invention belongs to the field of ornamental flower seed technology, specifically relating to an antifungal biological coating agent for ornamental flower seeds and its preparation method. Background Technology

[0002] Ornamental flowers are an important part of the global horticulture industry, and the quality of their seedlings directly affects the economic benefits of flower production. Ornamental flower seeds are small (such as petunias and pansies), with thin seed coats and large specific surface areas, making them susceptible to mechanical damage during sowing and seedling cultivation. Furthermore, their natural antibacterial barrier is weak, and most flower seeds have high oil content, resulting in vigorous respiration during germination and sensitivity to water and oxygen requirements. In humid environments, they are easily susceptible to soil-borne fungal diseases such as damping-off, seedling blight, and gray mold, leading to low germination rates. While traditional chemical fungicides (such as carbendazim and thiram) are effective, they pose risks of residual toxicity, environmental pollution, and resistance, and do not align with the trends of organic horticulture and ecological planting.

[0003] Therefore, there is an urgent need for a biological coating agent that provides physical protection, biological control, and nutrient supply. Summary of the Invention

[0004] The purpose of this invention is to provide an antifungal biological coating agent for ornamental flower seeds and its preparation method, in order to solve the above-mentioned technical problems in the prior art.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] The technical solution provided by this invention is as follows:

[0007] In a first aspect, the present invention provides an antifungal biological coating agent for ornamental flower seeds, wherein the antifungal biological coating agent for ornamental flower seeds specifically comprises the following components by weight:

[0008] Polymer film-forming agent 1.5-3g, antibacterial polymer powder 0.7-1.5g, composite antifungal agent 0.1-0.3g, auxiliary agent 2-5g, inorganic mineral filler 90-95g, binder 0.5-1.5g.

[0009] Preferably, the polymer film-forming agent includes at least one of carboxymethyl hydroxypropyl guar gum, hydroxypropyl methylcellulose (HPMC), and sodium carboxymethyl cellulose (CMC).

[0010] Preferably, the method for preparing the antibacterial polymer powder includes the following steps:

[0011] S1: L-menthol is dissolved in dichloromethane, and cyanuric chloride and catalyst are added under stirring and cooling in an ice-water bath. The mixture is then reacted in an ice bath to remove impurities and obtain monosubstituted cyanuric chloride.

[0012] In the above process, the first chlorine atom of cyanuric chloride is replaced by menthol.

[0013] S2: Monosubstituted cyanuric chloride, 4-aminobenzoic acid and catalyst are added to N,N-dimethylformamide, heated, stirred and refluxed, cooled to room temperature, pH adjusted, filtered and collected, washed and vacuum dried to obtain modified cyanuric chloride.

[0014] In the above process, the two remaining chlorine atoms on the triazine ring are replaced by p-aminobenzoic acid, providing carboxyl reaction sites for subsequent polymerization.

[0015] S3: In a nitrogen atmosphere and under ice bath conditions, the modified cyanuric chloride, hydrophilic comonomer, ethylene glycol, catalyst and dichloromethane are mixed and stirred. Then, a condensing agent is slowly added dropwise. The reaction continues in the ice bath for 0.3-0.7 hours. The temperature is raised to room temperature and heated under reflux. After continuous stirring, impurities are removed, the mixture is vacuum dried, ground and sieved to obtain antibacterial polymer powder.

[0016] The above technical solutions involve introducing hydrophilic comonomer PEG-400 segments to construct stable hydrophilic microdomains within the polymer without disrupting the inherent hydrophobic antibacterial framework. This achieves an external hydrophobic anti-adhesion effect and an internal hydrophilic permeability effect. Hydrophobicity and membrane disruption effects: The L-menthol fragment is a strongly hydrophobic group that can insert into and disrupt the lipid bilayer structure of the cell membrane through hydrophobic interactions. This disrupts the regular arrangement of proteins and lipids on the membrane, increases cell membrane permeability, and leads to the leakage of important substances such as potassium ions, ATP, and nucleic acids, ultimately causing cellular metabolic disorders, energy depletion, and death. The triazine ring is an electron-rich system that can electrostatically interact with positively charged components on the surface of fungal cell membranes or negatively charged biomolecules inside the cells, interfering with normal cell membrane function and microbial nucleic acid metabolism.

[0017] Preferably, in step S1, the ratio of L-menthol, dichloromethane, cyanuric chloride, and catalyst is 9.4-19 g: 20-40 mL: 5.5-11 g: 4-8 mL; the catalyst is 2,4,6-trimethylpyridine; the reaction time is 10-14 h; the impurity removal method is as follows: after reaction in an ice bath, wash with water 3-5 times, separate and dry the organic phase with anhydrous sodium sulfate, filter, remove the solvent by rotary evaporation, and purify the crude product by silica gel column chromatography with petroleum ether and dichloromethane in a volume ratio of 5:1 as the eluent.

[0018] Preferably, in S2, the ratio of monosubstituted cyanuric chloride, 4-aminobenzoic acid, catalyst, and N,N-dimethylformamide is 1.8-3.6g:4.1-8.2g:0.2-0.4g:20-40mL; the catalyst is pyridine; the heating temperature is 115-125℃; the stirring and reflux time is 5-7h; the pH adjustment method is to adjust the pH to 3.0 with 10wt% hydrochloric acid solution; the washing method is to wash with water 3-5 times; and the vacuum drying method is to vacuum dry at 55-65℃ to constant weight.

[0019] Preferably, in step S3, the ratio of modified cyanuric chloride, hydrophilic comonomer, ethylene glycol, catalyst, dichloromethane, and condensing agent is 8-16g:1.6-3.2g:1-2g:0.27-0.54g:20-40mL:6.1-12.2g; the hydrophilic comonomer is PEG-400; the catalyst is 4-dimethylaminopyridine p-toluenesulfonate; the stirring time is 20-30min; and the slow dropwise addition time is 2... 5-35 min; condensing agent is diisopropylcarbodiimide (DIC); reaction time continues for 0.3-0.7 h; heating temperature is 40-45℃; continuous stirring reaction time is 96-120 h; impurity removal method: precipitate by adding dropwise to 200 mL of ice-cold anhydrous diethyl ether, and wash 3-5 times with a mixture of diethyl ether and methanol; vacuum drying method: vacuum dry to constant weight at 40-50℃; antibacterial polymer particle size range is 50-100 μm.

[0020] Preferably, the compound antifungal agent is obtained by compounding Bacillus subtilis and Actinomycetes in a mass ratio of 1:1.

[0021] Preferably, the auxiliary agent specifically comprises the following components by weight: 0.5-1.5g potassium humate, 0.5-1.5g seaweed extract, 0.05-0.15g amino oligosaccharide, and 0.001-0.005g gibberellin.

[0022] The above technical solutions include: adding potassium humate to promote root growth and improve the microenvironment; seaweed extract to provide trace elements and stimulants; amino oligosaccharides to stimulate plant resistance; and gibberellin to promote plant cell elongation while removing substances that inhibit embryo growth inside the seed, thereby breaking seed dormancy and promoting seed germination.

[0023] Preferably, the seaweed extract is obtained by blending seaweed polysaccharides and seaweed oligosaccharides at a mass ratio of (2-5):1.

[0024] The inorganic mineral filler specifically includes the following components by weight: 30-40g diatomaceous earth, 25-35g calcined kaolin, 15-25g zeolite powder, and 5-10g anhydrous potassium magnesium alum powder.

[0025] Preferably, the adhesive is polyvinyl alcohol powder (PVA, type 1788).

[0026] The above technical solutions utilize the following methods: diatomaceous earth is lightweight, porous, and can absorb active ingredients; calcined kaolin is smooth and improves fluidity; zeolite powder retains water and fertilizer and facilitates ion exchange; anhydrous potassium magnesium alum powder slowly releases K, Mg, and S; and binders and polymer film-forming agents synergistically enhance the mechanical strength of the coating layer.

[0027] Secondly, the present invention also provides a method for preparing an antifungal biological coating agent for ornamental flower seeds, comprising the following steps:

[0028] Mix the inorganic mineral filler according to the ratio for 30-40 minutes, then add the polymer film-forming agent, binder, composite antifungal agent and auxiliary agent, continue mixing for 20-30 minutes, then add the antibacterial polymer powder, mix for another 10-15 minutes, and pass through a 100-mesh sieve to obtain an antifungal biological coating agent for ornamental flower seeds.

[0029] By adopting the above technical solution, the prepared coating agent has a certain pore structure, which is beneficial to the water retention and nutrient loss prevention performance of the coating agent.

[0030] Preferably, the application of the antifungal biological coating agent for ornamental flower seeds is achieved through the following steps:

[0031] Step (1) Seed disinfection: Disinfect the flower seeds with 0.5% potassium permanganate solution for 1 hour, then rinse with distilled water 5-6 times to obtain disinfected seeds;

[0032] Step (2) Mix the antifungal biological coating agent for ornamental flower seeds with water at a weight ratio of 1:1.2-1.5 under stirring until homogeneous, and let stand for 15-30 minutes to obtain a viscous slurry;

[0033] Step (3) Add the viscous slurry to the coating machine containing the sterilized seeds in small amounts and in multiple drops. After each addition of slurry, immediately sprinkle a small amount of antifungal biological coating agent for ornamental flower seeds into the coating machine. The coating layer is rolled and pressed to be dense and smooth by the rotation of the coating machine until the sterilized seeds achieve a weight gain of 3-8%. The coated seeds can be dried in a cool and ventilated place for 24-48 hours.

[0034] The mass ratio of the disinfected seeds to the coating agent is (100:3-8) of the total mass of the antifungal biological coating agent dry powder.

[0035] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are:

[0036] 1. This invention uses natural polymeric film-forming agents such as carboxymethyl hydroxypropyl guar gum and composite fillers such as calcined kaolin and diatomaceous earth to form a dense and porous coating layer on the seed surface, which can effectively isolate the direct infection of soil-borne pathogens, while maintaining appropriate air and water permeability to prevent seed suffocation. By using an antibacterial polymer, hydrophobic antibacterial groups derived from L-menthol are intercalated with hydrophilic segments of PEG-400. When the antibacterial polymer comes into contact with water in the coating layer, the hydrophilic segments absorb water and swell to form a slow-release channel, allowing the hydrophobic antibacterial components to be released in a controlled and sustained manner, forming long-lasting protection. The compounded Bacillus subtilis and actinomycetes rapidly colonize around the seeds, directly inhibiting or killing pathogenic fungi through multiple mechanisms such as competing for nutrient sites, secreting lipopeptide antibiotics, and producing cell wall degrading enzymes. At the same time, they induce systemic resistance in the seeds, synergistically improving the antibacterial properties of the seeds. The antibacterial polymer contains hydrophilic groups and film-forming functional groups in its molecular structure, which helps to improve the density and flexibility of the coating layer and enhance the binding force between the coating and the seed surface.

[0037] 2. This invention utilizes the high ion exchange capacity and adsorption properties of zeolite powder, combined with the porous structure of diatomaceous earth, to jointly regulate the moisture and gas balance around the seeds. Anhydrous potassium magnesium sulfate, as a natural mineral fertilizer, slowly decomposes and releases key elements such as potassium, magnesium, and sulfur under the action of soil microorganisms, meeting the needs of seed germination and early seedling growth, and avoiding nutrient waste or seedling burn. The trace amount of gibberellin in the coating agent can specifically break seed dormancy and promote embryo cell elongation. In synergy with the trace elements and biostimulants provided by potassium humate and seaweed extract, it significantly improves the uniformity of germination and the robustness of seedlings.

[0038] 3. This invention, through the synergistic effect of PVA binder and polymer film-forming agent, and the rational gradation of composite mineral fillers, enables the coating agent to possess excellent flowability and mixing uniformity, facilitating industrial production. The coating agent of this invention can achieve multiple functions—disease prevention, growth promotion, and water retention—in a single coating step, reducing the labor and material costs of subsequent topdressing and spraying, and has promising application prospects. Attached Figure Description

[0039] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0040] Figure 1 This is a line graph showing the germination rate of the antifungal biological coating agent for ornamental flower seeds of the present invention;

[0041] Figure 2This is a line graph showing the seedling incidence rate of the antifungal biological coating agent for ornamental flower seeds of the present invention. Detailed Implementation

[0042] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0043] Example 1

[0044] This embodiment discloses a method for preparing antibacterial polymer powder, including the following steps:

[0045] S1: Dissolve 15g L-menthol in 30mL dichloromethane. Under stirring and cooling in an ice-water bath, add 8.5g cyanuric chloride and 6mL 2,4,6-trimethylpyridine. React in an ice bath for 12h. After washing with water 4 times, separate and dry the organic phase with anhydrous sodium sulfate. Filter and concentrate by rotary evaporation to remove the solvent. Purify the crude product by silica gel column chromatography with petroleum ether and dichloromethane in a volume ratio of 5:1 to obtain monosubstituted cyanuric chloride.

[0046] S2: 2.7g of monosubstituted cyanuric chloride, 6.2g of 4-aminobenzoic acid and 0.3g of pyridine were added to 30mL of N,N-dimethylformamide, heated to 120℃, stirred and refluxed for 6h, cooled to room temperature, and then the pH was adjusted to 3.0 with 10wt% hydrochloric acid solution. The solid was collected by filtration and washed with water 4 times. Finally, it was vacuum dried at 60℃ to constant weight to obtain modified cyanuric chloride.

[0047] S3: In a nitrogen atmosphere and under ice bath conditions, 12g of modified cyanuric chloride, 2.4g of hydrophilic comonomer PEG-400, 1.5g of ethylene glycol, 0.41g of 4-dimethylaminopyridine p-toluenesulfonate, and 30mL of dichloromethane were mixed and stirred for 25min. Then, 9g of DIC was slowly added dropwise over 30min. The reaction was continued in an ice bath for 0.5h. The temperature was raised to room temperature and then heated to 42℃ under reflux. After stirring continuously for 105h, the precipitate was added dropwise to 200mL of ice-cold anhydrous diethyl ether and washed four times with a mixture of diethyl ether and methanol. The precipitate was then vacuum dried at 45℃ to constant weight, ground, and sieved to obtain antibacterial polymer powder.

[0048] Example 2

[0049] This embodiment discloses a method for preparing an antifungal biological coating agent for ornamental flower seeds, comprising the following steps:

[0050] Mix 92g of inorganic mineral filler for 35 minutes, then add 2.2g of polymer film-forming agent, 1g of binder, 0.2g of composite antifungal agent, and 3.5g of auxiliary agent, continue mixing for 25 minutes, then add 1.1g of antibacterial polymer powder prepared in Example 1, mix for another 12 minutes, and pass through a 100-mesh sieve to obtain an antifungal biological coating agent for ornamental flower seeds.

[0051] The polymer film-forming agent is carboxymethyl hydroxypropyl guar gum.

[0052] The compound antifungal agent is obtained by mixing Bacillus subtilis and Actinomycetes in a mass ratio of 1:1.

[0053] The auxiliary agent specifically comprises the following components by weight: 1g potassium humate, 1g seaweed extract, 0.1g amino oligosaccharide, and 0.003g gibberellin.

[0054] The seaweed extract is obtained by blending seaweed polysaccharides and seaweed oligosaccharides at a mass ratio of 3.5:1.

[0055] The inorganic mineral filler comprises the following components by weight: 35g diatomaceous earth, 30g calcined kaolin, 20g zeolite powder, and 7.5g anhydrous potassium magnesium alum powder.

[0056] The adhesive is PVA, type 1788 powder.

[0057] Example 3

[0058] This embodiment discloses a method for preparing an antifungal biological coating agent for ornamental flower seeds, comprising the following steps:

[0059] Mix 90g of inorganic mineral filler for 40min, then add 1.5g of polymer film-forming agent, 1.5g of binder, 0.1g of composite antifungal agent, and 5g of auxiliary agent, continue mixing for 20min, then add 1.5g of antibacterial polymer powder prepared in Example 1, mix for another 10min, and pass through a 100-mesh sieve to obtain an antifungal biological coating agent for ornamental flower seeds.

[0060] The polymer film-forming agent includes hydroxypropyl methylcellulose.

[0061] The compound antifungal agent is obtained by mixing Bacillus subtilis and Actinomycetes in a mass ratio of 1:1.

[0062] The auxiliary agent specifically comprises the following components by weight: 1.5g potassium humate, 0.5g seaweed extract, 0.15g amino oligosaccharide, and 0.001g gibberellin.

[0063] The seaweed extract is obtained by blending seaweed polysaccharides and seaweed oligosaccharides at a mass ratio of 5:1.

[0064] The inorganic mineral filler comprises the following components by weight: 30g diatomaceous earth, 35g calcined kaolin, 15g zeolite powder, and 10g anhydrous potassium magnesium alum powder.

[0065] The adhesive is PVA, type 1788 powder.

[0066] Example 4

[0067] This embodiment discloses a method for preparing an antifungal biological coating agent for ornamental flower seeds, comprising the following steps:

[0068] Mix 95g of inorganic mineral filler for 30 minutes, then add 3g of polymer film-forming agent, 0.5g of binder, 0.3g of composite antifungal agent, and 2g of auxiliary agent, and continue mixing for 30 minutes. Then add 0.7g of antibacterial polymer powder prepared in Example 1, mix for another 15 minutes, and pass through a 100-mesh sieve to obtain an antifungal biological coating agent for ornamental flower seeds.

[0069] The polymer film-forming agent is at least one of sodium CMC.

[0070] The compound antifungal agent is obtained by mixing Bacillus subtilis and Actinomycetes in a mass ratio of 1:1.

[0071] The auxiliary agent specifically comprises the following components by weight: 0.5g potassium humate, 1.5g seaweed extract, 0.05g amino oligosaccharide, and 0.005g gibberellin.

[0072] The seaweed extract is obtained by blending seaweed polysaccharides and seaweed oligosaccharides at a mass ratio of 2:1.

[0073] The inorganic mineral filler comprises the following components by weight: 40g diatomaceous earth, 25g calcined kaolin, 25g zeolite powder, and 5g anhydrous potassium magnesium alum powder.

[0074] The adhesive is PVA, type 1788 powder.

[0075] Comparative Example 1

[0076] Compared with Example 2, Comparative Example 1 did not add antibacterial polymer powder during the preparation of antifungal bio-coating agent for ornamental flower seeds, and all other conditions remained unchanged.

[0077] Comparative Example 2

[0078] Compared with Example 2, Comparative Example 2 did not add a compound antifungal agent in the process of preparing an antifungal biological coating agent for ornamental flower seeds, and all other conditions remained unchanged.

[0079] Comparative Example 3

[0080] Compared with Example 2, Comparative Example 3 used the chemical fungicide carbendazim to replace the compound antifungal agent in the preparation of the antifungal biological coating agent for ornamental flower seeds, while keeping all other conditions unchanged.

[0081] Comparative Example 4

[0082] Compared with Example 2, Comparative Example 4 used diatomaceous earth instead of inorganic mineral filler in the preparation of antifungal biological coating agent for ornamental flower seeds, while keeping other conditions unchanged.

[0083] Application examples

[0084] This application example discloses the application of an antifungal biological coating agent for ornamental flower seeds, achieved through the following steps:

[0085] Step (1) Seed disinfection: Disinfect the flower seeds with 0.5% potassium permanganate solution for 1 hour, then rinse with distilled water 5 times to obtain disinfected seeds;

[0086] Step (2) Mix the prepared antifungal biological coating agent for ornamental flower seeds with water at a weight ratio of 1:1.3 under stirring until homogeneous, let stand for 25 minutes to obtain a viscous slurry;

[0087] Step (3) The viscous slurry is added dropwise to the coating machine containing the sterilized seeds in small amounts. After each addition of slurry, a small amount of the prepared antifungal biological coating agent for ornamental flower seeds is immediately sprinkled into the coating machine. The coating layer is rolled and pressed to be dense and smooth by the rotation of the coating machine until the sterilized seeds reach a 6% weight gain. The coated seeds are then dried in a cool and ventilated place for 35 hours.

[0088] Experimental methods:

[0089] Ornamental petunia seeds were selected and coated with the coating agents of Examples 2-4 and Comparative Examples 1-4 respectively. The application treatment method of the antifungal biological coating agent for ornamental flower seeds was the same as that of the application examples. Standard germination and pot experiments were carried out, with 100 seeds treated in each group and repeated 3 times.

[0090] Test metrics:

[0091] Germination rate (%): Statistical analysis on day 7; Seedling disease incidence (%): The proportion of diseased seedlings was counted on day 14 after inoculation of Rhizoctonia solani in the seedling substrate; Fresh weight of seedlings (mg / plant): Measured on day 21, and the average value was taken; Coating shedding rate (%): Measured by standard shaking method after coating drying. The test results are shown in Table 1.

[0092] Table 1

[0093] Group Germination rate / % Seedling disease incidence rate / % Fresh weight of seedlings (mg / plant) Coating shedding rate / % Example 2 96.9 7.2 245 2.1 Example 3 95.7 8.5 238 2.5 Example 4 95.5 7.9 241 2.8 Comparative Example 1 88.2 22.5 210 5.5 Comparative Example 2 85.6 45.3 195 2.3 Comparative Example 3 91.2 15.8 225 2.0 Comparative Example 4 90.1 18.6 205 8.9

[0094] According to Table 1 and from Examples 2-4 and Comparative Examples 1-4, the antifungal biological coating agent for ornamental flower seeds prepared in the embodiments of the present invention has good germination-promoting properties, excellent antifungal and disease-preventing effects, significant seedling growth-promoting effects, and excellent coating adhesion stability.

[0095] As can be seen from the comparison between Comparative Example 1 and Examples 2-4, the antibacterial polymer powder has broad-spectrum antibacterial activity, which can effectively inhibit pathogenic fungi on the seed surface and in the surrounding environment, reducing the chance of infection. At the same time, its molecular structure contains hydrophilic groups and film-forming functional groups, which helps to improve the density and flexibility of the coating layer, enhance the binding force between the coating and the seed surface, and reduce the shedding rate. In addition, its slow-release properties can provide continuous protection for the early stage of seed germination, indirectly promoting the vigorous growth of seedlings. Therefore, the performance was reduced because the antibacterial polymer powder was not added.

[0096] The comparison between Comparative Example 2 and Examples 2-4 shows that Bacillus subtilis and Actinomycetes, as biocontrol microorganisms, can inhibit soil-borne pathogens through multiple mechanisms such as competitive colonization, secretion of antimicrobial substances, and induction of systemic resistance. Without the addition of compound antifungal agents, the seed susceptibility rate in the pathogen-laden substrate is reduced, hindering germination and early growth.

[0097] As can be seen from the comparison of Comparative Example 3 and Examples 2-4, although carbendazim has fungicidal activity, its spectrum of action is narrow, it is easy to develop drug resistance, and it is easy to produce non-target inhibition on the seed micro-ecological environment, weakening seed vigor and seedling growth potential. It lacks the dual biological control, immediate antibacterial and long-term ecological regulation effects of the compound antifungal agent of this invention.

[0098] As can be seen from the comparison between Comparative Example 4 and Examples 2-4, diatomaceous earth provides a porous structure, which is conducive to air permeability and moisture regulation. Calcined kaolin enhances the mechanical strength and light-blocking properties of the coating. Zeolite powder has ion exchange and slow-release capabilities, which can adsorb / release beneficial elements. Anhydrous potassium magnesium sulfate provides nutrients such as potassium and magnesium, promoting germination and stress resistance. A single filler cannot achieve the above-mentioned multifunctional synergy, resulting in a loose coating structure, poor adhesion, and insufficient nutrient supply, which in turn affects the seed germination quality and disease resistance.

[0099] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

[0100] The preferred embodiments of the present invention disclosed above are merely illustrative of the invention. These preferred embodiments do not exhaustively describe all details, nor do they limit the invention to specific implementations. Clearly, many modifications and variations can be made based on the content of this specification. This specification selects and specifically describes these embodiments to better explain the principles and practical applications of the invention, thereby enabling those skilled in the art to better understand and utilize the invention. The invention is limited only by the claims and their full scope and equivalents.

Claims

1. An antifungal biological coating agent for ornamental flower seeds, characterized in that, The antifungal biological coating agent for ornamental flower seeds specifically comprises the following components by weight: Polymer film-forming agent 1.5-3g, antibacterial polymer powder 0.7-1.5g, composite antifungal agent 0.1-0.3g, auxiliary agent 2-5g, inorganic mineral filler 90-95g, binder 0.5-1.5g.

2. The antifungal biological coating agent for ornamental flower seeds according to claim 1, characterized in that, The polymer film-forming agent includes at least one of carboxymethyl hydroxypropyl guar gum, hydroxypropyl methylcellulose (HPMC), and sodium carboxymethyl cellulose (CMC).

3. The antifungal biological coating agent for ornamental flower seeds according to claim 1, characterized in that, The method for preparing the antibacterial polymer powder includes the following steps: S1: L-menthol is dissolved in dichloromethane, and cyanuric chloride and catalyst are added under stirring and cooling in an ice-water bath. The mixture is then reacted in an ice bath to remove impurities and obtain monosubstituted cyanuric chloride. S2: Monosubstituted cyanuric chloride, 4-aminobenzoic acid and catalyst are added to N,N-dimethylformamide, heated, stirred and refluxed, cooled to room temperature, pH adjusted, filtered and collected, washed and vacuum dried to obtain modified cyanuric chloride. S3: In a nitrogen atmosphere and under ice bath conditions, the modified cyanuric chloride, hydrophilic comonomer, ethylene glycol, catalyst and dichloromethane are mixed and stirred. Then, a condensing agent is slowly added dropwise. The reaction continues in the ice bath for 0.3-0.7 hours. The temperature is raised to room temperature and heated under reflux. After continuous stirring, impurities are removed, the mixture is vacuum dried, ground and sieved to obtain antibacterial polymer powder.

4. The antifungal biological coating agent for ornamental flower seeds according to claim 3, characterized in that, In S1, the molar ratio of L-menthol, dichloromethane, cyanuric chloride, and catalyst is 9.4-19 g: 20-40 mL: 5.5-11 g: 4-8 mL; the catalyst is 2,4,6-trimethylpyridine; the reaction time is 10-14 h; the impurity removal method is as follows: after reaction in an ice bath, wash with water 3-5 times, separate and dry the organic phase with anhydrous sodium sulfate, filter, concentrate by rotary evaporation to remove solvent, and purify the crude product by silica gel column chromatography with petroleum ether and dichloromethane in a volume ratio of 5:

1.

5. The antifungal biological coating agent for ornamental flower seeds according to claim 3, characterized in that, In S2, the ratio of monosubstituted cyanuric chloride, 4-aminobenzoic acid, catalyst, and N,N-dimethylformamide is 1.8-3.6 g: 4.1-8.2 g: 0.2-0.4 g: 20-40 mL; the catalyst is pyridine; the heating temperature is 115-125℃; the stirring and reflux time is 5-7 h; the pH is adjusted to 3.0 using a 10 wt% hydrochloric acid solution. Washing method: Wash with water 3-5 times; Vacuum drying method: Vacuum dry at 55-65℃ until constant weight.

6. The antifungal biological coating agent for ornamental flower seeds according to claim 3, characterized in that, In step S3, the ratio of modified cyanuric chloride, hydrophilic comonomer, ethylene glycol, catalyst, dichloromethane, and condensing agent is 8-16g:1.6-3.2g:1-2g:0.27-0.54g:20-40mL:6.1-12.2g; the hydrophilic comonomer is PEG-400; the catalyst is 4-dimethylaminopyridine p-toluenesulfonate; the stirring time is 20-30min; and the slow dropwise addition time is 25- 35 min; condensing agent is diisopropylcarbodiimide (DIC); reaction time continues for 0.3-0.7 h; heating temperature is 40-45℃; continuous stirring reaction time is 96-120 h; impurity removal method: precipitate by adding dropwise to 200 mL of ice-cold anhydrous diethyl ether, and wash 3-5 times with a mixture of diethyl ether and methanol; vacuum drying method: vacuum dry to constant weight at 40-50℃; antibacterial polymer particle size range is 50-100 μm.

7. The antifungal biological coating agent for ornamental flower seeds according to claim 1, characterized in that, The compound antifungal agent is obtained by mixing Bacillus subtilis and Actinomycetes in a mass ratio of 1:

1.

8. The antifungal biological coating agent for ornamental flower seeds according to claim 1, characterized in that, The auxiliary agent specifically comprises the following components by weight: potassium humate 0.5-1.5g, seaweed extract 0.5-1.5g, amino oligosaccharide 0.05-0.15g, and gibberellin 0.001-0.005g.

9. The antifungal biological coating agent for ornamental flower seeds according to claim 1, characterized in that, The seaweed extract is obtained by blending seaweed polysaccharide and seaweed oligosaccharide at a mass ratio of (2-5):1; the inorganic mineral filler specifically includes the following components by weight: diatomaceous earth 30-40g, calcined kaolin 25-35g, zeolite powder 15-25g, anhydrous potassium magnesium alum powder 5-10g; the binder is polyvinyl alcohol powder.

10. A method for preparing an antifungal biological coating agent for ornamental flower seeds according to any one of claims 1-9, characterized in that, Includes the following steps: Mix the inorganic mineral filler according to the ratio for 30-40 minutes, then add the polymer film-forming agent, binder, composite antifungal agent and auxiliary agent, continue mixing for 20-30 minutes, then add the antibacterial polymer powder, mix for another 10-15 minutes, and pass through a 100-mesh sieve to obtain an antifungal biological coating agent for ornamental flower seeds.

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