Seed coating method and seed coating composition using iron chelate bond

Abstract

The present invention relates to a seed coating method using iron chelate bonds and a composition for seed coating. The seed coating method according to the present invention can prevent infection, decay, and damage from pests and diseases caused by endemic fungi by suppressing seed contamination by endemic fungi, and enables the promotion of germination rates and post-germination crop growth. Furthermore, compared to existing synthetic polymer-based seed coating technologies and bleach disinfection methods, the coating process is faster, mass coating is easy, and the seeds themselves are not damaged, thereby enabling a relative increase in germination rates and growth promotion. Thus, it is expected that this will contribute significantly to the development of the seed industry by replacing existing technologies in the domestic market, where agriculture is essential.

Description

Technology Field

[0001] The present invention relates to a seed coating method using iron chelate bonds and a composition for seed coating. Background Technology

[0002] Recently, due to the global increase in population and limited arable land for food cultivation, interest in finding ways to improve food production has grown, leading to active research on the production of high-value seeds using advanced coating processing technology.

[0003] It is well known that plants require energy, nitrogen, phosphorus, potassium, secondary nutrients, micronutrients, water, and carbon or carbon dioxide to grow. When a plant seed first germinates and forms a small seedling, carbon, nutrients, and energy available for growth are stored within the seed. Everything necessary to grow until the seedling can form roots and produce leaves is stored inside the seed.

[0004] Most harmful microorganisms, such as pathogens present in seeds that cause problems in plants, originate from the seeds themselves. Seeds are highly susceptible to damage from infection, decay, and pests caused by these endophytes. Since the environment in which crops are grown provides suitable temperature and humidity for microbial growth, pathogens can exist at high levels during the final stages of crop production even if the seeds are contaminated at low levels; therefore, endophytes present in the seeds must be eliminated through a decontamination process. Consequently, sterilization technology for harmful microorganisms in seeds must be capable of sterilizing them without affecting the germination rate of the seeds.

[0005] The most commonly used conventional method for seed sterilization is immersing seeds in liquid disinfectants. For example, according to data released by the Horticultural Research Institute of the Rural Development Administration, the general practice for disinfecting cucurbit crop seeds involves adding 100cc of bleach to 1L of water, soaking the seeds for 5 minutes, and then rinsing them about four times under running water before sowing. However, this conventional bleach-based seed disinfection method can damage seeds and inhibit germination. Furthermore, synthetic polymer-based seed coatings are technically saturated, necessitating the discovery of new seed coating technologies.

[0006] While researching seed coatings to prevent infection and decay caused by endemic fungi of seeds, the applicants developed a seed coating method using iron chelate bonds and a seed coating composition, thereby completing the present invention. The problem to be solved

[0007] The present invention was conceived to solve the aforementioned problems and aims to provide a seed coating method using iron chelate bonds and a composition for seed coating.

[0008] The technical problems of the present invention are not limited to those mentioned above, and other unmentioned technical problems will be clearly understood by a person skilled in the art from the description below. means of solving the problem

[0009] To solve the above technical problem, the present invention comprises: a) a step of adjusting the pH by adding a basic pH adjuster to an aqueous solution of a heterocyclic compound containing a carboxyl group;

[0010] b) a step of spraying the solution from step a) onto the seeds;

[0011] c) a step of spraying an iron salt aqueous solution onto the seeds from step b) above;

[0012] d) a step of drying the seeds sprayed with the above solution; comprising,

[0013] Herein, a seed coating method is provided in which the heterocyclic compound is a monocyclic compound containing one or more heteroatoms selected from oxygen, sulfur, and nitrogen within the molecule.

[0014] In addition, the present invention provides a seed coated according to the seed coating method.

[0015] In addition, the present invention provides a two-liquid type seed coating composition and a seed coating kit comprising: a first solution comprising an aqueous solution of a heterocyclic compound containing a carboxyl group and a basic pH adjuster; and a second solution comprising an aqueous solution of an iron salt; and a spraying means for spraying the first solution and the second solution, respectively, wherein the heterocyclic compound is a monocyclic compound containing one or more heteroatoms selected from oxygen, sulfur, and nitrogen within the molecule. Effects of the invention

[0016] The seed coating method according to the present invention can prevent infection, decay, and damage from pests and diseases caused by endemic fungi by suppressing contamination of seeds by endemic fungi, and can promote germination rates and post-germination crop growth. Furthermore, compared to existing synthetic polymer-based seed coating technologies and bleach disinfection methods, the coating process is faster, mass coating is easy, and it does not damage the seeds themselves, thereby enabling a relative increase in germination rates and growth promotion. As a result, it is expected to contribute significantly to the development of the seed industry by replacing existing technologies in the domestic market, where agriculture is essential.

[0017] The effects of the present invention are not limited to those mentioned above, and include other effects that are clearly understood by a person skilled in the art from the description throughout the specification but are not explicitly mentioned. Brief explanation of the drawing

[0018] FIG. 1 is a schematic diagram showing one embodiment of a seed coating process according to the present invention. Figure 2 is a figure showing a comparison of photographs of lettuce seeds before and after seed coating according to the present invention. Figure 3a is a figure showing the surface of lettuce seeds before and after seed coating according to the present invention, analyzed using SEM-EDS surface analysis equipment. Figure 3b is a figure showing the analysis of iron ions present on the surface of lettuce seeds before and after seed coating according to the present invention. Figure 4 is a figure showing the results of a growth test conducted on Petri dishes using undisinfected lettuce seeds, divided into before and after seed coating according to the present invention. Figure 5 is a figure showing the results of a growth test conducted in 6-wells on lettuce seeds that were not treated with disinfection, divided into before and after seed coating according to the present invention. Figure 6 is a figure showing the results of confirming the fungal infection rate of undisinfected lettuce seeds before and after seed coating according to the present invention. Figure 7a is a figure showing the results of a growth test of disinfected lettuce seeds without seed coating according to the present invention. FIG. 7b is a figure showing the results of a growth test on lettuce seeds that were not treated with disinfection after seed coating according to the present invention. Figure 8 is a graph showing the seed germination rate measured by dividing lettuce seeds into uncoated seeds and lettuce seeds coated without disinfection after disinfection. Figure 9 is a graph showing the biomass fresh weight measured and divided into uncoated lettuce seeds and coated lettuce seeds without disinfection after disinfection. Specific details for implementing the invention

[0019] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the attached drawings. The advantages and features of the present invention and the methods for achieving them will become clear by referring to the embodiments described below in detail together with the attached drawings. However, the present invention is not limited to the embodiments disclosed below but can be implemented in various different forms. These embodiments are provided merely to ensure that the disclosure of the present invention is complete and to fully inform those skilled in the art of the scope of the invention, and the present invention is defined only by the scope of the claims. Throughout the specification, the same reference numerals refer to the same components.

[0020] Unless otherwise defined, all terms used herein (including technical and scientific terms) may be used in a meaning commonly understood by those skilled in the art to which the present invention pertains. Furthermore, terms defined in commonly used dictionaries are not to be interpreted ideally or excessively unless explicitly and specifically defined otherwise. The terms used herein are for describing embodiments and are not intended to limit the present invention. In this specification, the singular form includes the plural form unless specifically stated otherwise in the text.

[0021] As used in the specification, "comprises" and / or "comprising" do not exclude the presence or addition of one or more other components, steps, actions, and / or elements to the mentioned components, steps, actions, and / or elements.

[0022] First, the present invention comprises the step of a) adjusting the pH by adding a basic pH adjuster to an aqueous solution of a heterocyclic compound containing a carboxyl group;

[0023] b) a step of spraying the solution from step a) onto the seeds;

[0024] c) a step of spraying an iron salt aqueous solution onto the seeds from step b) above;

[0025] d) a step of drying the seeds sprayed with the above solution; provides a seed coating method comprising

[0026] Step a) above is a step of adjusting the pH by adding a pH adjuster to an organic acid as a chelating agent, and the heterocyclic compound containing a carboxyl group means a monocyclic compound containing one or more heteroatoms selected from oxygen, sulfur, and nitrogen in the molecule.

[0027] The heterocyclic compound containing the above carboxyl group may preferably be dipicolinic acid, but is not limited thereto.

[0028] Dipicolinic acid is a substance present in large quantities in bacterial endospores; its presence is known to impart heat resistance to the spores, and it has the chemical formula C5H3N(COOH)2. Dipicolinic acid acts as a tridentate ligand due to the oxygen and nitrogen atoms of its two carboxylic acid groups, enabling it to form chelate compounds with many metals.

[0029] Commonly used representative chelating agents include ethylenediaminetetraacetate (EDTA), nitrilotriacetate (NTA), cyclohexanediaminetetraacetate (CDTA), and diethylenetriaminepentaacetate (DTPA), but organic acids have a lower unit cost than the above chelating agents, which can improve price competitiveness and can serve as an environmentally friendly chelating agent with high biodegradability.

[0030] In the case of organic acid-iron chelate compounds, the stability can be significantly affected by the pH of the solution, so a pH adjuster may be used. If the pH of the solution is 5 or lower, the degree of dissociation of most weak organic acids is insufficient, which may reduce the stability of the iron-organic acid chelate.

[0031] The above basic pH adjuster may include NaOH, Na2CO3, and KOH, and most preferably, K, an essential element for plants. + KOH containing [the substance] may be used. Due to the basic pH adjuster, the pH of the solution can preferably be adjusted to 8 to 10, and most preferably to 10. If the pH is 8 or lower, the chelate bond between the organic acid and the metal may not form strongly, and if the pH is 10 or higher, the high pH may cause damage to the seeds.

[0032] Step b) above is the step of spraying the solution from Step a) onto the seeds once it is prepared. The spraying can be performed using a spray nozzle.

[0033] Step c) above is a step of spraying an aqueous iron salt solution onto seeds sprayed with the solution of Step a), for the purpose of forming organic acid-iron chelate bonds on the surface of the seeds.

[0034] The above iron salt must be a substance capable of dissolving in an aqueous solution to form iron ions, preferably Fe(NO3)3, FeCl3, or FeSO4, and most preferably FeSO4.

[0035] Steps b) and c) above may each be repeated two or more times, and preferably three times each.

[0036] The drying in step d) above can be performed for 20 to 72 hours, and preferably for 24 or 48 hours.

[0037] To further strengthen the seed coating, steps b) to d) can be repeated after drying.

[0038] The seeds used in the present invention can be of any type, but preferably they can be leafy vegetables, and more preferably lettuce.

[0039] The seed coating method according to the present invention inhibits contamination of seeds by endogenous fungi, thereby preventing infection, decay, and damage from pests and diseases caused by endogenous fungi. Additionally, after seed germination, the iron chelate bond is easily broken by organic acids in the root exudate, and the freed iron ions are absorbed by the crop as nutrients to promote growth.

[0040] In addition, compared to existing synthetic polymer-based seed coating technologies and bleach disinfection methods, the coating process is faster, mass coating is easy, and it does not damage the seeds themselves, so it is possible to increase the relative germination rate and promote growth.

[0041] In addition, the present invention provides a seed coated according to the seed coating method.

[0042] In addition, the present invention provides a two-liquid type seed coating composition comprising: a first solution comprising an aqueous solution of a heterocyclic compound containing a carboxyl group and a basic pH adjuster; and a second solution comprising an aqueous solution of an iron salt, wherein the heterocyclic compound is a monocyclic compound containing one or more heteroatoms selected from oxygen, sulfur, and nitrogen within the molecule.

[0043] The above heterocyclic compound is a monocyclic compound containing one or more heteroatoms selected from oxygen, sulfur, and nitrogen within the molecule, preferably dipicolinic acid, but is not limited thereto.

[0044] The above basic pH adjuster may include NaOH, Na2CO3, and KOH, and most preferably, K, an essential element for plants. + KOH containing [the substance] may be used. Due to the pH adjuster, the pH of the first solution may preferably be adjusted to 8 to 10, and most preferably to 10.

[0045] The above iron salt must be a substance capable of dissolving in an aqueous solution to form iron ions, preferably Fe(NO3)3, FeCl3, or FeSO4, and most preferably FeSO4.

[0046] The above composition may further include an oxidation stabilizer (radical scavenger), an antifoaming agent, an antifreeze agent, etc., as additives.

[0047] The above composition is characterized by being a two-component type, consisting of a first solution and a second solution that forms a chelate bond on the surface of a seed.

[0048] In addition, the present invention may provide a two-liquid type seed coating kit comprising: a first solution comprising an aqueous solution of a heterocyclic compound containing a carboxyl group and a basic pH adjuster; and a second solution comprising an aqueous solution of an iron salt, wherein the heterocyclic compound is a monocyclic compound containing one or more heteroatoms selected from oxygen, sulfur, and nitrogen within the molecule.

[0050] Below, specific embodiments and experimental examples of the present invention are examined.

[0052] Example 1: Seed coating process using iron chelate bonding

[0053] An example of the seed coating process of the present invention is schematically illustrated in FIG. 1. As shown in FIG. 1, 50 mg of dipicolinic acid was dissolved in 2.5 ml of ethanol and 2.5 ml of distilled water, and then 1 N KOH was added to raise the pH to 10 to prepare a first solution, and 50 mg of FeSO4 was dissolved in 5 ml of distilled water to prepare a second solution. Then, the first and second solutions were sprayed onto prepared lettuce seeds three times each, and the seeds were coated by drying for one day.

[0054] To strengthen the above coating, the first and second solutions were sprayed onto the dried seeds twice each, and the seeds were dried for two days to provide an additional coating.

[0056] Experimental Example 1: Confirmation of changes after seed coating

[0057] 1-1. Observation of color change after seed coating

[0058] A photograph of the lettuce seeds coated in Example 1 above is shown in Figure 2, compared with the one before coating.

[0059] As shown in Figure 2, it was possible to visually confirm that the surface color of the seed had changed after coating.

[0061] 1-2. Surface analysis after seed coating

[0062] The surface of the lettuce seeds coated in Example 1 above was analyzed using SEM-EDS surface analysis equipment, and this is shown in Fig. 3a. In addition, the iron ions present on the surface were analyzed and this is shown in Fig. 3b.

[0063] As shown in Fig. 3a, it was confirmed that the surface was clearly different after coating, and as shown in Fig. 3b, it was confirmed that the organic acid-iron chelate structure was coated on the surface of the seed.

[0065] Experimental Example 2: Growth test of undisinfected seeds

[0066] After coating untreated lettuce seeds as in Example 1 above, the growth was evaluated by culturing them on MS Agar medium before and after coating, and the results are shown in Fig. 4 (Petri dish) and Fig. 5 (6-well).

[0067] As shown in Figures 4 and 5, the infection by fungi on the seed coat or endophytes inside the seed was very high in the case of seeds before coating, but in the case of coated seeds, even though they were not disinfected, the infection by fungi was significantly reduced compared to the seeds before coating, and it was confirmed that biomass increased.

[0069] Experimental Example 3: Confirmation of fungal infection rate in seeds not treated with disinfection

[0070] The seeds of Experimental Example 2 above were cultured on MS Agar medium for 8 days, and the fungal infection rate was measured every 12 hours, and the results are shown in Fig. 6.

[0071] As shown in Figure 6, it was confirmed that the expression of fungi in the coated seeds was significantly reduced. In particular, in the case of Petri dishes, the effect was excellent, with the expression of fungi in the coated seeds being less than about 5%.

[0073] Experimental Example 4: Growth test of disinfected and coated seeds

[0074] Lettuce seeds disinfected with 25% bleach using the conventional method were cultured on MS Agar medium without coating, and their growth was evaluated; the results are shown in Fig. 7a. In addition, seeds that had not been disinfected were coated as in Example 1 and cultured on MS Agar medium using the same method, and their growth was evaluated; the results are shown in Fig. 7b.

[0075] As shown in Figures 7a and 7b, it was confirmed that while conventional bleach-based disinfection has excellent bactericidal power, it inhibits seed germination and does not significantly induce crop growth. Conversely, in the case of seeds coated according to the present invention without disinfection treatment, fungal growth was observed in a few individuals as they were not disinfected with bleach, but it was confirmed that crop growth was significantly increased.

[0076] The seed germination rate confirmed in the above experiment was measured and shown as a graph in Figure 8.

[0077] As shown in Figure 8, it was confirmed that there was a significant difference in the seed germination rate, with the Coating group coated without disinfection showing an increase of about 17% compared to the Washing group not coated after disinfection. This suggests that the germination rate was inhibited because the seeds were damaged by bleach.

[0078] In addition, the biomass weight confirmed in the above experiment was measured and shown as a graph in Figure 9.

[0079] As shown in Figure 9, similar to the results in Figure 8, it was confirmed that the biomass fresh weight of the Coating group, coated without disinfection, increased by approximately 19 mg compared to the Washing group, which was not coated after disinfection, showing a significant difference. This suggests that crop growth was promoted by the organic acid-iron coating film. It is believed that when the seeds germinate and roots emerge, the seed coat is physically broken, causing the coating film to be physically dismantled. Simultaneously, the organic acid in the root exudate breaks down the organic acid-iron chelate bond, and the dismantled iron ions are absorbed by the crop, thereby promoting growth.

[0081] Although embodiments of the present invention have been described above with reference to the attached drawings, those skilled in the art will understand that the present invention may be implemented in other specific forms without changing its technical concept or essential features. Therefore, the embodiments described above should be understood as illustrative in all respects and not restrictive.

Claims

Claim 1 a) a step of adjusting the pH to 8 to 10 by adding a basic pH adjuster to an aqueous solution of a heterocyclic compound containing a carboxyl group; b) a step of spraying the solution of step a) onto a seed; c) a step of spraying an aqueous iron salt solution onto the seed of step b) so that an organic acid-iron chelate structure is formed on the surface of the seed; and d) a step of drying the seed onto which the solution was sprayed; wherein the heterocyclic compound is a monocyclic compound containing one or more heteroatoms selected from oxygen, sulfur, and nitrogen within the molecule. Claim 2 A seed coating method according to claim 1, characterized in that the heterocyclic compound containing a carboxyl group in step a) is dipicolinic acid. Claim 3 A seed coating method according to claim 1, wherein the basic pH adjuster in step a) is selected from the group consisting of NaOH, Na2CO3 and KOH. Claim 4 A seed coating method according to paragraph 3, characterized in that the basic pH adjuster is KOH. Claim 5 delete Claim 6 A seed coating method according to claim 1, wherein the iron salt in step c) is selected from the group consisting of Fe(NO3)3, FeCl3, and FeSO4. Claim 7 A seed coating method according to claim 6, characterized in that the iron salt is FeSO4. Claim 8 A seed coating method according to claim 1, characterized in that steps b) and c) are each repeated at least twice. Claim 9 A seed coating method according to claim 1, characterized in that the drying in step d) is performed for 20 to 72 hours. Claim 10 A seed coating method according to claim 1, characterized in that steps b) to d) are performed again after step d). Claim 11 A seed coating method according to claim 1, characterized in that the seed is a leafy vegetable seed. Claim 12 A seed coating method according to claim 11, characterized in that the leafy vegetable is lettuce. Claim 13 Seeds coated according to any one of the seed coating methods of paragraphs 1 to 4 and paragraphs 6 to 12. Claim 14 A two-liquid type seed coating composition comprising: a first solution with a pH adjusted to 8 to 10 by including an aqueous solution of a heterocyclic compound containing a carboxyl group and a basic pH adjuster; and a second solution containing an aqueous solution of an iron salt; wherein the first solution and the second solution are sequentially applied to a seed so that the heterocyclic compound containing a carboxyl group and iron ions form an organic acid-iron chelate structure on the surface of the seed, and the heterocyclic compound is a monocyclic compound containing one or more heteroatoms selected from oxygen, sulfur, and nitrogen within the molecule. Claim 15 A two-component seed coating composition according to claim 14, characterized in that the heterocyclic compound containing the carboxyl group is dipicolinic acid. Claim 16 A two-component seed coating composition according to claim 14, characterized in that the basic pH adjuster is selected from the group consisting of NaOH, Na2CO3 and KOH. Claim 17 A two-component seed coating composition according to claim 16, characterized in that the basic pH adjuster is KOH. Claim 18 delete Claim 19 A two-component seed coating composition according to claim 14, characterized in that the iron salt is selected from the group consisting of Fe(NO3)3, FeCl3, and FeSO4. Claim 20 A two-component seed coating composition according to claim 19, characterized in that the iron salt is FeSO4. Claim 21 A two-liquid type seed coating kit comprising: a first solution with a pH adjusted to 8 to 10 by including an aqueous solution of a heterocyclic compound containing a carboxyl group and a basic pH adjuster; and a second solution containing an aqueous solution of an iron salt; and a spraying means for spraying the first solution and the second solution, respectively, wherein the first solution and the second solution are applied sequentially to a seed so that the heterocyclic compound containing a carboxyl group and iron ions form an organic acid-iron chelate structure on the surface of the seed, and the heterocyclic compound is a monocyclic compound containing one or more heteroatoms selected from oxygen, sulfur, and nitrogen within the molecule.

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