Nano-enzyme-like seed coating agent for promoting low-temperature germination of maize and its coating method

Abstract

This invention relates to a nano-enzyme-simulating seed coating agent that promotes low-temperature germination of maize and its coating method. It utilizes spherical manganese-based nano-enzymes to prepare a suitable concentration of the nano-enzyme-simulating agent, which is then mixed with a seed coating agent in a specific ratio for coating maize seeds. This improves the cold resistance of spring-sown maize to low-temperature damage, significantly increasing the germination rate and emergence rate of maize seeds under low temperatures, resulting in faster and more uniform emergence. This reduces the risk of low-temperature damage to spring-sown maize in northern regions, promoting early sowing and high yields. Furthermore, this invention is simple to operate, allowing the nano-enzyme-simulating agent to be used as an active ingredient in the seed coating agent, upgrading existing seed coating agent products and facilitating production and widespread application.

Description

Technical Field

[0001] This invention relates to the field of seed coating technology, specifically to a nano-enzyme-simulating seed coating agent that promotes low-temperature germination of maize and its coating method. Background Technology

[0002] In northern my country's spring maize growing regions, low-temperature damage is frequently encountered during the sowing and emergence period, resulting in slow emergence, uneven growth, severe seedling loss, reduced chlorophyll content in seedling leaves, decreased and shortened root numbers, deformities, and weak seedlings, ultimately hindering the establishment of high-quality, high-yield populations. Currently, various measures to combat low temperatures in maize have been explored and adopted in production, such as selecting early-maturing varieties and delaying sowing to avoid low temperatures, but this reduces the potential yield to some extent. Other methods involve spraying exogenous growth regulators during the seedling stage to improve cold resistance, but these are often applied only after cold damage has occurred, leading to insufficient timely control and limited ability to regulate cold damage during the sowing and emergence stages, thus offering limited regulation of low-temperature stress during seedling growth. Seed coating technology for maize is widely used in production, but currently, the active ingredients in seed coating agents mainly consist of disease-preventing, insect-repelling, growth-promoting regulators, and supplements of micronutrients. There are no reports of adding active ingredients to seed coating agents to enhance maize's low-temperature tolerance, thereby improving germination, seedling emergence, and seedling cold resistance.

[0003] Chinese invention patent CN113735175A discloses a manganese-based oxide nano-enzyme, which is a spherical manganese-based oxide nano-enzyme modified with a surfactant. It exhibits good water solubility and can exist stably in a high-concentration colloidal form. When applied as a seed-initiated or foliar fertilizer, it can improve the salt and drought tolerance of rapeseed. Nano-enzyme regulators possess many unique physicochemical properties, including small size effects, surface and interface effects, and macroscopic quantum tunneling effects, showing broad application potential. The unique properties of nano-enzyme regulators make them easier to absorb and more environmentally friendly. However, research and technological applications of nano-enzymes in regulating low-temperature tolerance in maize have not yet been reported. Summary of the Invention

[0004] Addressing the issue of low-temperature chilling injury in maize in northern and southwestern spring-sown maize areas, this invention aims to overcome the shortcomings of existing technologies by providing a nano-enzyme-simulating seed coating agent and its coating method to promote maize germination under low temperatures. This invention improves the delayed germination and weak seedlings caused by low-temperature chilling injury, accelerates maize emergence, and increases germination and seedling survival rates. It helps farmers to sow maize in a timely manner when encountering spring-sown chilling injury, further increases the selection of maize varieties and sowing times during spring sowing, and reduces the risk of yield reduction.

[0005] To achieve the above objectives, the technical solution designed by the present invention is as follows:

[0006] A nano-enzyme-like seed coating agent that promotes low-temperature germination of maize, wherein the nano-enzyme-like seed coating agent is a mixture of a seed coating agent and a nano-enzyme-like budding agent; wherein the volume ratio of the seed coating agent to the nano-enzyme-like budding agent is 1:1.6-2.0.

[0007] Preferably, the volume ratio of the seed coating agent to the nano-enzyme chaperone is 1:1.8.

[0008] Preferably, the concentration of the nano-enzyme chaperone is 160-240 mg / L.

[0009] Preferably, the mass fraction of the nano-enzyme chaperone seed coating agent is 0.010%-0.020%.

[0010] Preferably, the mass fraction of the nano-enzyme budding agent in the nano-enzyme budding agent is 0.012%-0.018%.

[0011] Preferably, the nano-enzyme is a spherical manganese-based oxide nano-enzyme. It is prepared by preparing the nano-enzyme stock solution according to the method disclosed in Chinese Invention Patent Publication No. CN113735175A (A nano-enzyme, preparation method and seed soaking agent containing the same).

[0012] Preferably, the seed coating agent includes a film-forming agent, the amount of which is determined according to the instructions provided with the commercially available pharmaceutical product.

[0013] Preferably, the seed coating agent also includes insecticides and fungicides (insecticides, fungicides and other active ingredients can also be selected and determined by the user).

[0014] The present invention also provides a method for coating corn seeds with the nano-enzyme-matching seed coating agent as described above. The method involves mixing clean corn seeds with the nano-enzyme-matching seed coating agent evenly (so that the color of the corn seeds is uniformly the color of the film-forming agent), and then ventilating and drying (after drying, the coated seeds will not lose color when rubbed).

[0015] Preferably, each kilogram of the said clean corn seeds requires mixing with 8-12 ml of nano-enzyme-simulating seed coating agent.

[0016] The principle of this invention:

[0017] 1. The nano-enzyme companion of the present invention is prepared by the method disclosed in Chinese Invention Patent No. CN113735175A, entitled "A nano-enzyme, preparation method and seed soaking agent containing the same", and is obtained by preparing the nano-enzyme mother liquor.

[0018] The aforementioned nano-enzyme mimicry originates from patent (ZL202110945779.4, a manganese foliar fertilizer and its preparation method). This patent describes spherical manganese-based oxide nano-enzymes modified with surfactants, exhibiting good water solubility and stable existence in a high-concentration colloidal form. When applied as seed-initiated or foliar fertilizer, it can improve the salt tolerance of rapeseed and the salt and cold tolerance of cotton. This invention develops the regulatory effect of this nano-enzyme mimicry material on the low-temperature tolerance of maize seedlings during germination and explores its feasibility in production applications, providing a more effective and feasible technology for combating low-temperature damage in maize production.

[0019] The preparation of the above-mentioned nano-enzyme mother liquor refers to the preparation method in the prior art (publication number CN113735175A, invention title "A nano-enzyme, preparation method and seed soaking agent containing the same"), and the main steps include:

[0020] A solution of 0.8 mol / L to 1.2 mol / L divalent manganese salt was mixed with a solution of 800 g / L to 1000 g / L polymeric surfactant at a volume ratio of 1:(1.5 to 2.5) to obtain solution A. Solution A was then added dropwise to ammonia water as a precipitant, with the final ratio being solution A volume : ammonia water volume = 1:(1.5 to 2.5). After purification by dialysis under oxygen-containing conditions, spherical manganese-based oxide nanoparticles of enzyme-like material were obtained, with a concentration of (x, g / L).

[0021] The method for preparing nano-enzyme chaperones using the above-mentioned nano-enzyme chaperone stock solution (taking the preparation of 1L of nano-enzyme chaperone as an example):

[0022] Weigh the above-mentioned nano-enzyme stock solution. The volume y (ml) of the nano-enzyme stock solution can be calculated using the following formula.

[0023] y = a / x

[0024] In the formula, y is the volume (ml) of the nano-enzyme stock solution, x is the concentration of the nano-enzyme stock solution, and a is the concentration (mg / L) of the nano-enzyme chaperone to be prepared.

[0025] Then, y ml of nano-enzyme stock solution was placed in a container, and (1000-y) ml of water was added to make up to 1000 ml to obtain amg / L nano-enzyme companion with a concentration of 160 mg / L to 240 mg / L.

[0026] 2. Preparation method of nano-enzyme-simulating seed coating agent:

[0027] (1) Seed coating agent preparation: Select a multi-component chemical seed coating agent that has high market acceptance, is resistant to storage, has a fast film-forming time, and is widely used in local corn-producing areas. It should include a film-forming agent and other active ingredients can be selectively selected according to local conditions.

[0028] According to the amount of seed coating agent Vc, add the nano-enzyme chaperone Vn prepared in step (2) at a ratio of 1:n, that is, Vn=n×Vc. The value of n can be determined by referring to the ratio of seed coating agent to added water in the seed coating agent instructions, and is generally 1:1.6~2.0.

[0029] (2) This invention uses Syngenta seed dressing agent for corn, which consists of three components: Rise 600fs, Man Yi Jia, and a red film-forming agent. Rise 600fs contains 46% thiamethoxam as its active ingredient, and Man Yi Jia contains metalaxyl, fludioxonil, and thiamethoxam as its active ingredients. The concentrations of metalaxyl, fludioxonil, and thiamethoxam are 20 g / L, 25 g / L, and 152 g / L, respectively.

[0030] Depending on the actual situation, different varieties of corn seeds can be selected. Seed coating agents containing film-forming agents can be chosen, or seed coating agents formed by combining insecticides, fungicides and other active ingredients with film-forming agents. Insecticides, fungicides and other active ingredients can be selected and determined by the user.

[0031] The beneficial effects of this invention are:

[0032] (1) Compared with existing seed coating agents, the spherical manganese-based oxide nano-enzyme chaperone of this invention, mixed with the seed coating agent, for coating maize seeds can significantly improve the cold resistance of maize during germination and seedling emergence at low temperatures, alleviate problems such as delayed seed development, missing seedlings, and weak seedlings caused by cold stress, accelerate the emergence progress of maize, increase the seedling rate, and reduce the risk of low-temperature damage. Compared with existing coated seeds, the coated seeds of this invention can emerge 3-5 days earlier at low temperatures, and improve the emergence rate and uniformity. Especially for spring maize in regions such as Heilongjiang, Inner Mongolia, and Jilin, the use of this technology can, to a certain extent, resist the impact of low-temperature weather, reduce the risk of early sowing, help farmers sow in time during spring sowing cold damage, achieve moderately early sowing and early emergence, strive for subsequent growth temperature accumulation, and promote stable and high yields.

[0033] (2) The present invention makes a seed coating agent companion by forming a spherical manganese-based oxide nano-enzyme, which can be combined with a variety of seed coating agents. It is easy to operate and easy to master, and can meet the needs of different users such as seed coating agent companies, seed production companies, and growers. Users can choose flexibly according to their own needs. Therefore, it can be used as an active ingredient in seed coating agents, upgrade existing seed coating agents, and facilitate production and promotion.

[0034] In summary, this invention provides a coating technology that can improve the germination rate, emergence rate, and stress resistance of maize seeds, resist damage caused by low temperature during germination, shorten the germination and emergence time of maize seeds under cold stress, and improve seedling quality. Multiple batches of experiments have verified that, compared with conventional coating technology, this coating technology can advance seedling emergence by 3-5 days under cold stress conditions. Attached Figure Description

[0035] Figure 1 A photograph of the coated seeds obtained in Example 1;

[0036] Figure 2 Photographs showing the different germination states of the coated seeds prepared in Comparative Example 3, Example 2, and Comparative Example 4 compared to the naked seeds in Comparative Example 5 on the 12th day of cultivation.

[0037] Figure 3 Photographs of the coated seeds (C) prepared in Example 2 (B), Comparative Example 4, and naked seeds (A) in Comparative Example 1 at different germination states on the 12th, 15th, and 18th days of cultivation.

[0038] Figure 4 Statistical graphs showing the different radicle lengths of coated seeds prepared in Examples 1-6 and Comparative Examples 1-4 on days 12, 15, and 10 of culture.

[0039] Figure 5 This is a schematic diagram showing the change in germination (seedling) height of the coated seeds obtained in Comparative Examples 1-4 as a function of the number of days since sowing.

[0040] Figure 6 This is a schematic diagram showing the change in germination (seedling) height of the coated seeds obtained in Examples 1-3 and Comparative Example 2 as a function of the number of days after sowing.

[0041] Figure 7 This is a schematic diagram showing the change in germination (seedling) height of the coated seeds obtained in Examples 4-6 and Comparative Example 2 as a function of the number of days after sowing.

[0042] Figure 8 This is a schematic diagram showing the change in germination rate of coated seeds prepared in Comparative Examples 1-4 and Comparative Example 2 with the number of days after sowing.

[0043] Figure 9 This is a schematic diagram showing the change in germination rate of coated seeds obtained in Examples 1-3 and Comparative Example 2 with the number of days after sowing.

[0044] Figure 10 This is a schematic diagram showing the change in germination rate of the coated seeds obtained in Examples 4-6 and Comparative Example 2 with the number of days since sowing. Detailed Implementation

[0045] The present invention will now be described in further detail with reference to specific embodiments, so that those skilled in the art can understand it.

[0046] Example 1

[0047] This embodiment (denoted as PMO160) provides a nano-enzyme-simulating seed coating agent and coating method for promoting low-temperature germination of maize, the steps of which are as follows:

[0048] 1. Preparation of spherical manganese-based nano-enzyme-simulating mother liquor, including the following steps:

[0049] A solution A was prepared by mixing 0.8 mol / L to 1.2 mol / L manganese sulfate solution with 800 g / L to 1000 g / L polyacrylic acid solution at a volume ratio of 1:(1.5 to 2.5). Ammonia water was then added dropwise as a precipitant, resulting in a final ratio of solution A volume to ammonia water volume of 1:(1.5 to 2.5). The mixture was stirred at 500 rpm for 24 hours using a magnetic stirrer. The stirred solution was then placed in a 50 mL polytetrafluoroethylene reactor and subjected to hydrothermal reaction at 120 °C for 24 hours. The resulting solution was aliquoted into 2 mL centrifuge tubes and centrifuged at 4000 g at room temperature for 1 hour. The supernatant was collected and dialyzed using a dialysis bag (MW 3500) for 24 hours, with water changed every 8 hours, to obtain a spherical manganese-based nano-enzyme stock solution with a concentration of 10 g / L.

[0050] 2. The example uses Syngenta seed coating agent, which consists of three components: Riesling 600fs, Maniq, and a red film-forming agent. Specifically, the active ingredient of Riesling 600fs is 46% thiamethoxam; the active ingredients of Maniq are 20 g / L metalaxyl, 25 g / L fludioxonil, and 152 g / L thiamethoxam.

[0051] 3. Preparation method of nano-enzyme-simulating seed coating agent to promote low-temperature germination of maize:

[0052] a. Dilute the spherical manganese-based nano-enzyme stock solution prepared by the above method with water to obtain a nano-enzyme chaperone with a concentration of 160 mg / L.

[0053] b. Weigh 4.2 mL of Syngenta seed coating agent, which contains 1.2 mL of Riesling, 1.0 mL of Mani-Gel, and 2.0 mL of red film-forming agent;

[0054] c. Weigh 7.5 ml of the nano-enzyme companion and mix it evenly with the Syngenta seed coating agent weighed in step b to obtain the nano-enzyme companion seed coating agent.

[0055] 4. A coating method to promote corn germination at low temperatures, including the following steps:

[0056] Weigh 1.0 kg of cleaned corn seeds and pour them into a container containing 11.7 mL of the nano-enzyme seed coating agent mixture prepared in step 3. Stir thoroughly to ensure the mixture evenly covers the seed surface, resulting in a uniform film-forming agent color. Then, dry the seeds in a fume hood at a wind speed of 0.42-0.52 m / s for 2 hours. The dried coated seeds are as follows: Figure 1 As shown, the film has a uniform color and covers an area of ​​over 90%.

[0057] The coated seeds were sown in a culture box, sprayed with water to absorb water for 20 hours to allow them to swell, and then placed in an incubator at 8°C for 7 days. Afterward, they were transferred to an artificial climate chamber at 25°C until germination. Germination progress, root growth, and seedling height were observed.

[0058] Example 2

[0059] This embodiment (denoted as PMO200) provides a nano-enzyme-simulating seed coating agent and coating method for promoting low-temperature germination of maize. The steps are basically the same as those in Example 1, except that in step 2, the concentration of the nano-enzyme-simulating agent is 200 mg / L.

[0060] Example 3

[0061] This embodiment (denoted as PMO300) provides a nano-enzyme-simulating seed coating agent and coating method for promoting low-temperature germination of maize. The steps are basically the same as those in Example 1, except that in step 2, the concentration of the nano-enzyme-simulating agent is 300 mg / L.

[0062] Example 4

[0063] This embodiment (denoted as PMO400) provides a nano-enzyme-simulating seed coating agent and coating method for promoting low-temperature germination of maize. The steps are basically the same as those in Example 1, except that in step 2, the concentration of the nano-enzyme-simulating agent is 400 mg / L.

[0064] Example 5

[0065] This embodiment (denoted as PMO500) provides a nano-enzyme-simulating seed coating agent and coating method for promoting low-temperature germination of maize. The steps are basically the same as those in Example 1, except that in step 2, the concentration of the nano-enzyme-simulating agent is 500 mg / L.

[0066] Example 6

[0067] This embodiment (denoted as PMO600) provides a nano-enzyme-simulating seed coating agent and coating method for promoting low-temperature germination of maize. The steps are basically the same as those in Example 1, except that in step 2, the concentration of the nano-enzyme-simulating agent is 600 mg / L.

[0068] Comparative Example 1

[0069] This comparative example (denoted as PMO20) provides a nano-enzyme-simulating seed coating agent and coating method for promoting low-temperature germination of maize. The steps are basically the same as those in Example 1, except that in step 2, the concentration of the nano-enzyme-simulating agent is 20 mg / L.

[0070] Comparative Example 2

[0071] This comparative example (denoted as PMO40) provides a nano-enzyme-simulating seed coating agent and coating method for promoting low-temperature germination of maize. The steps are basically the same as those in Example 1, except that in step 2, the concentration of the nano-enzyme-simulating agent is 40 mg / L.

[0072] Comparative Example 3

[0073] This comparative example (denoted as PMO80) provides a nano-enzyme-simulating seed coating agent and coating method for promoting low-temperature germination of maize. The steps are basically the same as those in Example 1, except that in step 2, the concentration of the nano-enzyme-simulating agent is 80 mg / L.

[0074] Comparative Example 4

[0075] In this comparative example (referred to as naked seeds), untreated naked corn seeds were sown into culture boxes, sprayed with water to absorb water for 20 hours, then placed in an incubator at 8°C for 7 days, and then transferred to an artificial climate chamber at 25°C until germination. Germination progress, root growth, seedling height, and other indicators were observed.

[0076] Comparative Example 5

[0077] This comparative example (denoted as coating agent) used only Syngenta seed coating agent. 1.2 ml of Riesling, 1.0 ml of Manigra, and 2.0 g of red film-forming agent were mixed and then mixed with 1 kg of corn to form a coating. The coated seeds were sown in culture boxes, sprayed with water to absorb water for 20 hours, and then placed in an incubator at 8℃ for 7 days. Afterward, they were transferred to an artificial climate chamber at 25℃ until germination. Germination progress, root growth, and seedling height were observed.

[0078] From the appendix Figure 2 Appendix Figure 3 It can be seen that the germination and emergence processes of maize under different treatments differed significantly. On day 12, the embryo height of the 200 mg / L nano-enzyme-simulant coating treatment was significantly higher than that of the naked seed treatment and the Syngenta seed coating treatment. On day 15, the naked seed treatment had not yet emerged, but the nano-enzyme-simulant coating treatment had already emerged, with some seedlings having two visible leaves. Therefore, the 200 mg / L nano-enzyme-simulant coating treatment significantly promoted the germination and emergence of maize, resulting in emergence approximately 7 days earlier than the naked seed treatment and 3-5 days earlier than the coating treatment.

[0079] From the appendix Figure 4 It was observed that on day 10 of cultivation, there were significant differences in radicle length among the treatments, with the seed coating treatment showing a significantly shorter radicle length than the nano-enzyme chaperone (PMO) coating treatments. Among all nano-enzyme chaperone concentration treatments, the radicle lengths were longest in the 160 mg / L and 200 mg / L nano-enzyme chaperone coating treatments.

[0080] From the appendix Figure 5-7It was observed that there were significant differences in bud (seedling) height among different treatments. After 15 days of cultivation, the bud (seedling) height treated with 20 mg / L and 40 mg / L nano-enzyme budding agent coatings showed no significant difference compared to the seed coating agent treatment. However, the bud (seedling) height treated with 80 mg / L and above nano-enzyme budding agent coatings was significantly higher than that of the seed coating agent treatment. Among these, the 160 mg / L, 200 mg / L, 300 mg / L, 400 mg / L, and 500 mg / L nano-enzyme budding agent coatings showed the most significant bud-promoting effect. By the end of cultivation (day 23), the average plant height of the seedlings in the coated control group was 92.3 mm; the average plant height in the 160 mg / L nano-enzyme budding agent treatment group was 150.0 mm; and the average plant height in the 200 mg / L nano-enzyme budding agent treatment group was 137.5 mm.

[0081] Appendix Figure 8-10 It can be seen that there are significant differences in germination rates among different treatments. With prolonged culture time, the germination rates of the 20 mg / L, 40 mg / L, and 80 mg / L nano-enzyme-simulating agent coating treatments were not significantly different from those of the seed coating agent treatment. However, the germination rates of the 160 mg / L, 200 mg / L, 300 mg / L, 400 mg / L, 500 mg / L, and 600 mg / L nano-enzyme-simulating agent coating treatments were significantly faster than those of the seed coating agent treatment. When the germination rate reached over 90%, the seed coating agent treatment took 20 days, while the 160 mg / L, 200 mg / L, 300 mg / L, 400 mg / L, 500 mg / L, and 600 mg / L nano-enzyme-simulating agent coating treatments only took 16-17 days. This demonstrates that the nano-enzyme-simulating agent coating treatment effectively promotes rapid and uniform germination of maize seeds.

[0082] All other parts not described in detail are existing technologies. Although the above embodiments have provided a detailed description of the present invention, they are only some embodiments of the present invention, not all embodiments. People can obtain other embodiments based on these embodiments without creative effort, and these embodiments all fall within the protection scope of the present invention.

Claims

1. The application of a nano-enzyme-simulating seed coating agent in promoting low-temperature germination of maize, characterized in that: The nano-enzyme-simulating seed coating agent is a mixture of a seed coating agent and a nano-enzyme-simulating agent; wherein the volume ratio of the seed coating agent to the nano-enzyme-simulating agent is 1:1.6~2.0; and the concentration of the nano-enzyme in the nano-enzyme-simulating agent is 160-240 mg / L; the nano-enzyme-simulating agent is a spherical manganese-based oxide nano-enzyme, which is prepared by the following steps: A solution of 0.8 mol / L to 1.2 mol / L divalent manganese salt was mixed with a solution of 800 g / L to 1000 g / L polymeric surfactant at a volume ratio of 1:(1.5 to 2.5) to obtain solution A. Solution A was then added dropwise to ammonia water as a precipitant, with a volume ratio of 1:(1.5 to 2.5). After purification by dialysis under oxygen-containing conditions, spherical manganese-based oxide nanoparticles of enzyme-like compounds were obtained.

2. The application according to claim 1, characterized in that: The seed coating agent includes a film-forming agent.

3. The application according to claim 1, characterized in that: The seed coating agent also includes insecticides and fungicides.

4. A coating method for promoting low-temperature germination of maize seeds, characterized in that: The method involves uniformly mixing clean corn seeds with a nano-enzyme-simulating seed coating agent, followed by ventilation and drying. The nano-enzyme-simulating seed coating agent is a mixture of the seed coating agent and the nano-enzyme-simulating agent; the volume ratio of the seed coating agent to the nano-enzyme-simulating agent is 1:1.6~2.0; and the concentration of the nano-enzyme in the nano-enzyme-simulating agent is 160-240 mg / L. The nano-enzyme-simulating agent is a spherical manganese-based oxide nano-enzyme, prepared by the following steps: A solution of 0.8 mol / L to 1.2 mol / L divalent manganese salt was mixed with a solution of 800 g / L to 1000 g / L polymeric surfactant at a volume ratio of 1:(1.5 to 2.5) to obtain solution A. Solution A was then added dropwise to ammonia water as a precipitant, with a volume ratio of 1:(1.5 to 2.5). After purification by dialysis under oxygen-containing conditions, spherical manganese-based oxide nanoparticles of enzyme-like compounds were obtained.

5. The coating method according to claim 4, characterized in that: For every kilogram of the aforementioned clean corn seeds, 8-12 ml of nano-enzyme-simulating seed coating agent needs to be mixed in.

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