Conditioner for improving crop stress resistance and preparation method thereof

Abstract

The invention relates to the technical field of conditioners, in particular to a conditioner for improving crop stress resistance and a preparation method thereof, and the conditioner comprises the following raw materials: plant hormones, trehalose, humic acid, a complex microbial inoculant, modified nano sodium alginate, modified nano zinc oxide, lactic acid, a green tea extract and a licorice extract. The modified nano-sodium alginate, the modified nano-zinc oxide and the lactic acid play a role through a synergistic effect, the modified nano-sodium alginate and nutrient substances form a modified nano-sodium alginate gel compound through physical adsorption and chemical effects, stress-resistant peptides on the surface of the compound directly activate immune systems of crops, synthesis of stress-resistant proteins is promoted, and the stress resistance of the crops is improved. The modified nano-zinc oxide enhances the absorption of nutrient substances by crop root cells, assists the activation of crop immune systems, and synergistically enhances the disease resistance and stress resistance of crops, and the lactic acid effectively stabilizes the pH value of the conditioner, relieves the oxidation pressure of crops under adverse conditions, and enhances the physiological stability of crops.

Description

Technical Field

[0001] The invention relates to the technical field of conditioners, in particular to a conditioner for improving crop stress resistance and a preparation method thereof. Background Art

[0002] As global climate change intensifies, extreme climate events (such as drought, saline-alkali soil, low temperature, high temperature, etc.) occur frequently, seriously affecting agricultural production. Especially in arid and saline-alkali areas, the growth of crops is greatly restricted, resulting in a decline in agricultural output and quality. Therefore, how to improve the stress resistance of crops has become an important topic in agricultural scientific research, and crop stress resistance conditioners, as an effective means to improve crop stress resistance, have become a research hotspot in agricultural production. Crop stress resistance refers to the ability of crops to maintain normal growth, development and yield under non-optimal growth conditions. Improving crop stress resistance can not only reduce the negative impact of environmental changes on crop growth, but also increase the adaptability of crops in harsh environments, thereby improving the stability of agricultural production. Studies have shown that effectively compounding multiple ingredients such as plant hormones, natural products, microbial agents and mineral elements into conditioners can achieve complementary and synergistic effects. This multi-effect synergistic effect can provide all-round protection for crops under different stress conditions and significantly improve the stress resistance of crops. Therefore, the use of conditioners to regulate the physiological processes of crops and thus enhance crop stress resistance has become a key issue in agricultural scientific research. It is of great significance to develop a safe and effective conditioner to improve crop stress resistance. Summary of the invention

[0003] (1) Technical issues to be solved

[0004] The purpose of the present invention is to provide a conditioner for improving crop stress resistance and a preparation method thereof, by optimizing the formula of the conditioner and combining modern nanotechnology to enhance the bioavailability of the conditioner, improve the microbial environment of the crop root system, and thereby effectively activate the crop's immune defense system, stimulate the crop to produce more disease-resistant and stress-resistant proteins, enhance the crop's stress resistance, promote crop growth, and achieve the goal of improving its disease resistance, drought resistance and salt-alkali resistance.

[0005] (2) Technical solution

[0006] To achieve the above object, on the one hand, the present invention provides a conditioning agent for improving crop stress resistance, comprising the following raw materials in parts by weight: 0.1-0.5 parts of plant hormone, 1-3 parts of trehalose, 1-3 parts of humic acid, 0.1-1 parts of composite bacterial agent, 1-2 parts of lactic acid, 0.04-0.1 parts of modified nano zinc oxide, 1-2 parts of green tea extract, 1-2 parts of licorice extract, and 8-10 parts of purified water;

[0007] The conditioning agent also includes:

[0008] Modified nano-alginate;

[0009] The modified nano-sodium alginate and lactic acid are in a weight ratio of 0.5:(1-2);

[0010] The modified nano-alginate is obtained by modifying the surface of nano-alginate with anti-adverse peptides. The nano-size of the modified nano-alginate is 80-120 nm, and the specific surface area is 120-150 m 2 / g.

[0011] Furthermore, the preparation method of the modified nano-sodium alginate comprises:

[0012] S11. Sodium alginate was dissolved in purified water under stirring, and calcium chloride was slowly added after stirring for 0.5 to 1 h, with the drop rate controlled at 1 to 2 drops / s, while the temperature was raised to 45 to 55°C, and stirring was continued for 2 to 3 h to obtain a first mixed solution;

[0013] S12. The first mixed solution was allowed to stand for 4 to 6 hours and then the solid-liquid separation was performed. The separated solid was washed five times with purified water and then placed in a vacuum drying oven for drying at a temperature of 70 to 80 ° C for a drying time of 12 to 18 hours to obtain nano-sodium alginate and ground into a powder for standby use;

[0014] S13. Dissolve the nano-sodium alginate in dichloromethane under stirring, add N-hydroxysuccinimide and 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride in sequence after stirring for 1 to 2 hours, and continue stirring for 4 to 6 hours to obtain a second mixed solution;

[0015] S14. dissolving the anti-adverse peptide in phosphate buffered saline and stirring for 1 to 2 hours until fully dissolved to obtain an anti-adverse peptide solution, slowly dropping the second mixed solution into the anti-adverse peptide solution and reacting for 18 to 24 hours to obtain a third mixed solution;

[0016] S15. The third mixed solution is subjected to high-speed centrifugation at a rotation speed of 10,000 to 12,000 rpm for 15 to 20 min. The separated solid is washed alternately with phosphate buffered saline and purified water for 3 times and then vacuum dried at a drying temperature of 40 to 50° C. After drying for 12 to 14 hours, the modified nano-sodium alginate is obtained and ground into powder for later use.

[0017] Furthermore, the mass ratio of the sodium alginate, calcium chloride and anti-adversity peptide is 1:(1-2):(0.02-0.05).

[0018] Furthermore, the plant hormone is a compound of gibberellins, cytokinins and abscisic acid, and the weight ratio of gibberellins, cytokinins and abscisic acid is (1-2): (0.5-1): (0.5-1).

[0019] Furthermore, the composite bacterial agent is a compound of nitrogen-fixing bacteria, root-promoting bacteria and Bacillus subtilis, and the weight ratio of nitrogen-fixing bacteria, root-promoting bacteria and Bacillus subtilis is (1-2): (0.5-1): (0.1-0.5).

[0020] Furthermore, the preparation method of the modified nano zinc oxide comprises:

[0021] S21. Dispersing zinc oxide in anhydrous ethanol under nitrogen protection and subjecting to ultrasonic treatment at an ultrasonic frequency of 40 to 50 kHz, 3-aminopropyltriethoxysilane was slowly added to reflux at room temperature for 0.5 to 1 h, and the reflux temperature was 75 to 80 ° C. After reflux for 6 to 8 h, a fourth mixed solution was obtained;

[0022] S22. The fourth mixed solution was subjected to high-speed centrifugation at a speed of 8000 to 10000 rpm for 15 to 20 min. The separated solid was washed three times with anhydrous ethanol and then vacuum dried at a drying temperature of 45 to 55 ° C. After drying for 8 to 12 h, the nano zinc oxide intermediate was ground into a powder for standby use.

[0023] S23. Dissolve polyvinyl alcohol in anhydrous ethanol under stirring, stir for 1 to 2 hours, slowly add 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride and N-hydroxysuccinimide, raise the temperature to 45 to 60° C., continue stirring for 4 to 6 hours to obtain a fifth mixed solution;

[0024] S24. Disperse the nano zinc oxide intermediate in anhydrous ethanol under light protection and nitrogen protection, slowly add the fifth mixed solution after stirring for 0.5 to 1 hour, and continue stirring at room temperature for 24 to 28 hours to obtain a sixth mixed solution;

[0025] S25. The sixth mixed solution is subjected to high-speed centrifugation at a rotation speed of 10,000 to 12,000 rpm for 15 to 20 minutes. The separated solid is washed with anhydrous ethanol 5 times and then vacuum dried at a drying temperature of 40 to 50° C. After drying for 12 to 14 hours, the modified nano zinc oxide is obtained and ground into powder for later use.

[0026] Furthermore, the modified nano zinc oxide is obtained by grafting polyvinyl alcohol on the surface of nano zinc oxide. The nano size of the modified nano zinc oxide is 40 to 60 nm, and the specific surface area is 120 to 150 m 2 / g.

[0027] On the other hand, based on the same inventive concept, the present invention also provides a method for preparing a conditioning agent for improving crop stress resistance, which is applied to the conditioning agent for improving crop stress resistance, comprising the following steps:

[0028] S31. Add trehalose and humic acid to purified water in a container and stir thoroughly. After stirring for 1 to 2 hours, perform ultrasonic treatment at an ultrasonic frequency of 40 to 50 kHz and an ultrasonic temperature of 40 to 50 ° C. After 0.5 to 1 hour of ultrasonic treatment, a seventh mixed solution is obtained;

[0029] S32. Under stirring, the modified nano-alginate sodium, modified nano-zinc oxide, lactic acid, green tea extract and licorice extract were added to the seventh mixed solution in sequence and stirred evenly, the stirring speed was 400 to 600 rpm, the stirring temperature was 45 to 55 ° C, and the mixture was ultrasonically treated for 2 to 4 hours at an ultrasonic frequency of 40 to 50 kHz for 0.5 to 1 hour to obtain an eighth mixed solution;

[0030] S33. After the eighth mixed solution is cooled to room temperature, the plant hormone and the composite bacterial agent are dissolved in purified water and sprayed evenly on the eighth mixed solution, and stirred again for 0.5 to 1 h and filtered through a 0.22 μm filter membrane to obtain a conditioning agent;

[0031] S34. Transfer the conditioner to a clean, dry storage container and store it in a dark place at a low temperature of 4 to 10°C.

[0032] The mechanism of action of the above raw material components is as follows:

[0033] Plant hormones are signal molecules that regulate growth and development in crops. Under stress conditions such as drought and salinity, abscisic acid is an important hormone for crop defense response. Abscisic acid reduces water evaporation by regulating the opening and closing of stomata, and at the same time regulates the expression of stress resistance genes to improve the drought resistance and salinity resistance of crops. Abscisic acid can also promote the synthesis of stress resistance proteins (such as antifreeze proteins and antioxidant enzymes) in crops to enhance the overall resistance of crops. Gibberellins and cytokinins are also commonly used to promote crop growth, improve crop photosynthesis efficiency, and help crops grow better in adverse conditions. Plant hormones regulate crop physiological responses by interacting with endogenous hormones in crops, help crops adapt to environmental changes, and enhance their immune system to increase stress resistance.

[0034] Trehalose is a natural disaccharide that is widely found in many plants and microorganisms, especially in some crops with strong stress resistance. Trehalose can help crops maintain water balance inside and outside cells under drought, salinity and other stress conditions through osmotic regulation, slow down cell water loss, effectively prevent cell dehydration and membrane system damage, enhance crop drought resistance, reduce oxidative damage caused by adversity through antioxidant effects, and enhance crop stress resistance protein synthesis.

[0035] Humic acid is a natural organic matter derived from the decomposition products of plants and animals. Humic acid, as a natural soil conditioner in the soil, has a significant effect in enhancing stress resistance. Humic acid can improve soil structure, increase soil water retention capacity, and promote the absorption of water and nutrients by crop roots. Humic acid can also form complexes with heavy metal ions to reduce the toxic effects of heavy metal ions on crops. At the same time, humic acid has a certain antioxidant effect, which can reduce oxidative damage in plants under adverse conditions. Humic acid not only improves the soil environment and increases nutrient utilization, but also enhances the root development of plants, helps crops better absorb water and nutrients in adverse conditions, and enhances their stress resistance.

[0036] Composite microbial agents are a type of preparation containing beneficial microorganisms, including nitrogen-fixing bacteria, root-promoting bacteria and Bacillus subtilis. Nitrogen-fixing bacteria can increase the nitrogen source available to plants through nitrogen fixation, while phosphorus- and potassium-solubilizing bacteria can provide the nutrients needed by plants and improve the efficiency of plant nutrient absorption. Root-promoting bacteria can regulate plant growth, promote the activation of the plant immune system and enhance the plant's resistance to stress by secreting plant growth hormones. Bacillus subtilis can inhibit the growth of pathogens through competitive inhibition and secretion of antibiotics, thereby improving the disease resistance of plants. The combined action of nitrogen-fixing bacteria, root-promoting bacteria and Bacillus subtilis with plant hormones, humic acid and other ingredients can effectively improve the plant's absorption of nutrients, enhance immune defense, and improve the rhizosphere environment to help plants better adapt to adversity.

[0037] Green tea extract is rich in polyphenols (such as tea polyphenols, catechins, etc.), and has powerful antioxidant, antibacterial, and anti-inflammatory effects. Tea polyphenols and catechins in green tea extract can scavenge free radicals and reduce oxidative damage to crops under adverse conditions. At the same time, green tea extract can also enhance the disease resistance of crops and inhibit the growth of pathogens. Licorice extract contains active ingredients such as glycyrrhizic acid and flavonoids, and has multiple biological activities such as antioxidant, anti-inflammatory, and antibacterial. Licorice extract can reduce oxidative damage to crops caused by adversity, promote the activation of the crop immune system, and enhance the stress resistance of crops, especially resistance to drought, disease, and salt and alkali resistance, through its antioxidant and immunomodulatory effects.

[0038] In the conditioner, modified nano-alginate, modified nano-zinc oxide and lactic acid play a role through synergistic effect. Sodium alginate is a natural polysaccharide extracted from brown algae with good biocompatibility. Modified nano-alginate is obtained by chemically modifying the surface of sodium alginate with anti-adverse peptides. In the preparation process of the conditioner, modified nano-alginate will form a modified nano-alginate gel complex with nutrients such as modified nano-zinc oxide, plant hormones, trehalose, humic acid, green tea extract and licorice extract through physical adsorption and chemical action. Nano-zinc oxide is a commonly used plant nutrition enhancer. Modified nano-zinc oxide is obtained by chemically modifying the surface of nano-zinc oxide with polyvinyl alcohol, which can further enhance the dispersion effect of modified nano-zinc oxide, avoid the agglomeration of modified nano-zinc oxide and modified nano-alginate, improve bioavailability, and also synergistically promote the complex effect of modified nano-alginate on nutrients and promote the formation of gel complex. When the conditioner acts on crops, the anti-adversity peptides on the surface of the modified nano-alginate gel complex will specifically bind to the receptors on the surface of the crop root cells, thereby triggering the signal transduction mechanism of the crop and inducing endocytosis, so that the modified nano-alginate gel complex is swallowed into the cell. In the intracellular environment, the modified nano-alginate gel complex is gradually dissociated, and the nutrients are gradually released for absorption and utilization by the crop cells, achieving slow release and precise absorption of nutrients. The anti-adversity peptides on the surface of modified nano-alginate will directly activate the crop's immune system, enhance the crop's ability to perceive adversity, and promote the synthesis of anti-adversity proteins. At the same time, nano-alginate has good water absorption, and by regulating the osmotic pressure of crop root cells, it helps cells maintain water balance in water-deficient or high-salt environments. The modified nano zinc oxide grafted with polyvinyl alcohol further enhances the absorption of nutrients by crop root cells. At the same time, the modified nano zinc oxide slowly releases zinc ions under the action of polyvinyl alcohol, providing trace elements for crops to promote plant growth, assisting the activation of crop immune systems, reducing oxidative damage caused by adversity, and enhancing the disease resistance and stress resistance of crops together with modified nano sodium alginate. However, when modified nano sodium alginate and modified nano zinc oxide exist at the same time, the pH value of the conditioner solution will be too high. Too high a pH value will affect the absorption of nutrients by plant roots, and will also cause stress to crops, affecting the growth and stress resistance of crops. The pH value of the conditioner can be effectively stabilized by adding lactic acid. Lactic acid is a weak organic acid that can provide hydrogen ions, and the generated lactate also has a buffering effect, thereby maintaining the stability and effectiveness of the conditioner. In addition, the antioxidant effect of lactic acid itself can remove free radicals generated under adversity, reduce oxidative damage to cell membranes, proteins and DNA, and can work with modified nano zinc oxide to alleviate the oxidative stress of crops under adverse conditions and enhance the physiological stability of crops.

[0039] (3) Beneficial effects

[0040] Compared with the prior art, the present invention has the following beneficial effects:

[0041] 1. Modified nano-sodium alginate, modified nano-zinc oxide and lactic acid play a role through synergistic effect. Modified nano-sodium alginate and nutrients such as modified nano-zinc oxide form modified nano-sodium alginate gel complex through physical adsorption and chemical action. Modified nano-zinc oxide synergistically promotes the complex effect of modified nano-sodium alginate on nutrients.

[0042] 2. The anti-adversity peptide on the surface of the modified nano-alginate gel complex specifically binds to the receptors on the surface of the crop root cells to trigger endocytosis. In the intracellular environment, the modified nano-alginate gel complex is gradually dissociated to release nutrients, achieving sustained release and precise absorption of nutrients;

[0043] 3. The anti-stress peptides on the surface of modified nano-sodium alginate activate the crop's immune system and promote the synthesis of anti-stress proteins. The modified nano-zinc oxide enhances the absorption of nutrients by crop root cells, assists in activating the crop's immune system, reduces oxidative damage to crops caused by adversity, and together with modified nano-sodium alginate enhances the crop's disease resistance and stress resistance.

[0044] 4. Lactic acid effectively stabilizes the pH value of the conditioner, maintains the stability and effectiveness of the conditioner, and together with modified nano zinc oxide, alleviates the oxidative stress of crops under adverse conditions and enhances the physiological stability of crops. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] Figure 1 This is the SEM image of the modified nano-sodium alginate in Example 1 of the present invention. DETAILED DESCRIPTION

[0046] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0047] The experimental equipment and preparations of the embodiments described below are as follows: electronic balance (Sartorius, Germany), electric constant temperature water bath (Jiangsu Kedao), magnetic stirrer (Shanghai Meiyingpu), vacuum drying oven (Shanghai Jiecheng), ultrasonic instrument (Shanghai Yixin), scanning electron microscope (Zeiss, Germany), specific surface area analyzer (Beijing Best Instrument Technology), composite bacterial agent (Shanghai Banon), handheld chlorophyll SPAD instrument (Qingdao Coreide), leaf area meter (Shandong Laiyin); chemicals and reagents were purchased from Sigma-Aldrich.

[0048] Example 1: This example discloses a conditioner for improving the stress resistance of crops, which comprises the following raw materials in parts by weight: 0.3 part of plant hormone, 2 parts of trehalose, 2 parts of humic acid, 0.5 part of compound bacterial agent, 1.5 parts of lactic acid, 0.07 part of modified nano zinc oxide, 1.5 parts of green tea extract, 1.5 parts of liquorice extract, and 9 parts of purified water; the conditioner further comprises modified nano sodium alginate, and the weight ratio of the modified nano sodium alginate to lactic acid is 0.5:1.5. The modified nano sodium alginate is obtained by modifying stress resistance peptides on the surface of nano sodium alginate, and the nano size of the modified nano sodium alginate is 80-120 nm, and the specific surface area is 120-150 m 2 / g.

[0049] In the conditioner, the modified nano sodium alginate, the modified nano zinc oxide and lactic acid play a role through synergistic effects. Sodium alginate is a natural polysaccharide substance extracted from brown algae. By chemical modification, stress resistance peptides are modified on the surface of sodium alginate to obtain modified nano sodium alginate, such as Figure 1As shown in the SEM image of modified nano sodium alginate, the modified nano sodium alginate has uniform particle size, spherical morphology and good biocompatibility. In the preparation process of the conditioner, the modified nano sodium alginate can be used as a carrier to adsorb nutrients such as modified nano zinc oxide, plant hormones, trehalose, humic acid, green tea extract and licorice extract. At the same time, the abundant hydrophilic hydroxyl (-OH) and carboxyl (-COOH) on the surface of the modified nano sodium alginate will interact with the hydroxyl (-OH) and carboxyl (-COOH) on the surface of these nutrients through intermolecular hydrogen bonds and covalent interactions to form a stable modified nano sodium alginate gel complex. Nano zinc oxide is a commonly used plant nutrition enhancer. Modified nano zinc oxide is obtained by grafting polyvinyl alcohol on the surface of nano zinc oxide through chemical modification. Polyvinyl alcohol is a hydrophilic polymer. The hydroxyl hydrophilic groups on its surface effectively enhance the stability of modified nano zinc oxide in solution, further enhance the dispersion of modified nano zinc oxide, and form a hydrophilic protective film on the surface of nano zinc oxide to avoid agglomeration of modified nano zinc oxide and modified nano sodium alginate, thereby improving the bioavailability of modified nano zinc oxide and modified nano sodium alginate, and synergistically promoting the complexing effect of modified nano sodium alginate on nutrients. The large number of hydroxyl groups (-OH) on the surface of polyvinyl alcohol can provide more hydrophilic and functionalized contact sites, thereby interacting with the hydrophilic groups on the surface of modified nano sodium alginate, plant hormones, and trehalose, further promoting the formation of gel complexes. When the conditioner acts on crops, the anti-adversity peptides on the surface of the modified nano-alginate gel complex will specifically bind to the receptors on the surface of the crop root cells (such as receptor kinases, G protein-coupled receptors, tyrosine kinase receptors, etc.) through the molecular recognition mechanism, thereby triggering the signal transduction mechanism in the cell and inducing endocytosis, so that the modified nano-alginate gel complex is swallowed into the cell. In the intracellular environment, the modified nano-alginate gel complex is gradually dissociated, and the nutrients are gradually released for absorption and utilization by the crop cells, achieving slow release and precise absorption of nutrients. The anti-adversity peptides on the surface of modified nano-alginate will directly activate mitogen-activated protein kinase (MAPK), Ca 2+, active oxygen and other signal pathways, activate the crop's immune system, enhance the crop's perception of adversity, and promote the synthesis of stress-resistant proteins. At the same time, nano-sodium alginate has good water absorption, and by adjusting the osmotic pressure of crop root cells, it helps cells maintain water balance in a water-deficient or high-salt environment. The modified nano-zinc oxide grafted with polyvinyl alcohol has a large specific surface area and rich pore structure, which further enhances the absorption of nutrients by crop root cells. At the same time, the modified nano-zinc oxide slowly releases zinc ions under the action of polyvinyl alcohol, providing crops with trace elements to promote plant growth and participate in chlorophyll synthesis, protein synthesis, antioxidant enzyme activity and other physiological processes, assisting in the activation of the crop immune system. Zinc ions can activate the antioxidant enzyme system in crops, reduce the damage of free radicals to crop cells, and reduce the oxidative damage of crops caused by adversity. Together with modified nano-sodium alginate, it enhances the disease resistance and stress resistance of crops, and helps crops resist pathogens and environmental stress. However, when modified nano-alginate and modified nano-zinc oxide are present at the same time, the pH value of the conditioner solution will be too high. Too high a pH value will affect the absorption of nutrients by plant roots, and will also cause stress to crops, affecting the growth and stress resistance of crops. The pH value of the conditioner can be effectively stabilized by adding lactic acid. Lactic acid is a weak organic acid that can generate hydrogen ions (H + ) and lactate ion (C 3 H 5 O 3 - ), and the lactate generated by the alkaline substances in the conditioner (such as modified nano-alginate and modified nano-zinc oxide) also has a buffering effect. Lactate will accept or release hydrogen ions, reduce the fluctuation of pH value, and lactic acid and lactate form a buffer system. The two work together to maintain the stability and effectiveness of the conditioner, avoid the negative impact of high pH value on the root system of crops, and promote the absorption of nutrients by plants. In addition, the antioxidant effect of lactic acid itself can remove free radicals produced under adverse conditions, reduce oxidative damage to cell membranes, proteins and DNA, and can work together with modified nano-zinc oxide to alleviate the oxidative stress of crops under adverse conditions, enhance the physiological stability of crops, and help crops better cope with adverse environments.

[0050] The preparation method of the modified nano sodium alginate comprises:

[0051] S11. Sodium alginate was dissolved in purified water under stirring, and calcium chloride was slowly added after stirring for 0.5 to 1 h, with the drop rate controlled at 1 to 2 drops / s, while the temperature was raised to 45 to 55°C, and stirring was continued for 2 to 3 h to obtain a first mixed solution;

[0052] S12. The first mixed solution was allowed to stand for 4 to 6 hours and then the solid-liquid separation was performed. The separated solid was washed five times with purified water and then placed in a vacuum drying oven for drying at a temperature of 70 to 80 ° C for a drying time of 12 to 18 hours to obtain nano-sodium alginate and ground into a powder for standby use;

[0053] S13. Dissolve the nano-sodium alginate in dichloromethane under stirring, add N-hydroxysuccinimide and 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride in sequence after stirring for 1 to 2 hours, and continue stirring for 4 to 6 hours to obtain a second mixed solution;

[0054] S14. dissolving the anti-adverse peptide in phosphate buffered saline and stirring for 1 to 2 hours until fully dissolved to obtain an anti-adverse peptide solution, slowly dropping the second mixed solution into the anti-adverse peptide solution and reacting for 18 to 24 hours to obtain a third mixed solution;

[0055] S15. The third mixed solution is subjected to high-speed centrifugation at a rotation speed of 10,000 to 12,000 rpm for 15 to 20 min. The separated solid is washed alternately with phosphate buffered saline and purified water for 3 times and then vacuum dried at a drying temperature of 40 to 50° C. After drying for 12 to 14 hours, the modified nano-sodium alginate is obtained and ground into powder for later use.

[0056] The mass ratio of the sodium alginate, calcium chloride and anti-adversity peptide is 1:(1-2):(0.02-0.05).

[0057] The plant hormone is a compound of gibberellin, cytokinin and abscisic acid, and the weight ratio of gibberellin, cytokinin and abscisic acid is (1-2): (0.5-1): (0.5-1).

[0058] The composite bacterial agent is a compound of nitrogen-fixing bacteria, root-promoting bacteria and Bacillus subtilis, wherein the weight ratio of the nitrogen-fixing bacteria, root-promoting bacteria and Bacillus subtilis is (1-2): (0.5-1): (0.1-0.5).

[0059] The preparation method of the modified nano zinc oxide comprises:

[0060] S21. Dispersing zinc oxide in anhydrous ethanol under nitrogen protection and subjecting to ultrasonic treatment at an ultrasonic frequency of 40 to 50 kHz, 3-aminopropyltriethoxysilane was slowly added to reflux at room temperature for 0.5 to 1 h, and the reflux temperature was 75 to 80 ° C. After reflux for 6 to 8 h, a fourth mixed solution was obtained;

[0061] S22. The fourth mixed solution was subjected to high-speed centrifugation at a speed of 8000 to 10000 rpm for 15 to 20 min. The separated solid was washed three times with anhydrous ethanol and then vacuum dried at a drying temperature of 45 to 55 ° C. After drying for 8 to 12 h, the nano zinc oxide intermediate was ground into a powder for standby use.

[0062] S23. Dissolve polyvinyl alcohol in anhydrous ethanol under stirring, stir for 1 to 2 hours, slowly add 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride and N-hydroxysuccinimide, raise the temperature to 45 to 60° C., continue stirring for 4 to 6 hours to obtain a fifth mixed solution;

[0063] S24. Disperse the nano zinc oxide intermediate in anhydrous ethanol under light protection and nitrogen protection, slowly add the fifth mixed solution after stirring for 0.5 to 1 hour, and continue stirring at room temperature for 24 to 28 hours to obtain a sixth mixed solution;

[0064] S25. The sixth mixed solution is subjected to high-speed centrifugation at a rotation speed of 10,000 to 12,000 rpm for 15 to 20 minutes. The separated solid is washed with anhydrous ethanol 5 times and then vacuum dried at a drying temperature of 40 to 50° C. After drying for 12 to 14 hours, the modified nano zinc oxide is obtained and ground into powder for later use.

[0065] The modified nano zinc oxide is obtained by grafting polyvinyl alcohol on the surface of nano zinc oxide. The nano size of the modified nano zinc oxide is 40-60 nm, and the specific surface area is 120-150 m 2 / g.

[0066] A method for preparing a conditioning agent for improving crop stress resistance, which is applied to the conditioning agent for improving crop stress resistance, comprises the following steps:

[0067] S31. Add trehalose and humic acid to purified water in a container and stir thoroughly. After stirring for 1 to 2 hours, perform ultrasonic treatment at an ultrasonic frequency of 40 to 50 kHz and an ultrasonic temperature of 40 to 50 ° C. After 0.5 to 1 hour of ultrasonic treatment, a seventh mixed solution is obtained;

[0068] S32. Under stirring, the modified nano-alginate sodium, modified nano-zinc oxide, lactic acid, green tea extract and licorice extract were added to the seventh mixed solution in sequence and stirred evenly, the stirring speed was 400 to 600 rpm, the stirring temperature was 45 to 55 ° C, and the mixture was ultrasonically treated for 2 to 4 hours at an ultrasonic frequency of 40 to 50 kHz for 0.5 to 1 hour to obtain an eighth mixed solution;

[0069] S33. After the eighth mixed solution is cooled to room temperature, the plant hormone and the composite bacterial agent are dissolved in purified water and sprayed evenly on the eighth mixed solution, and stirred again for 0.5 to 1 h and filtered through a 0.22 μm filter membrane to obtain a conditioning agent;

[0070] S34. Transfer the conditioner to a clean, dry storage container and store it in a dark place at a low temperature of 4 to 10°C.

[0071] Example 2: This example discloses a conditioning agent for improving crop stress resistance, comprising the following raw materials in parts by weight: 0.1 part of plant hormone, 1 part of trehalose, 1 part of humic acid, 0.1 part of composite bacterial agent, 1 part of lactic acid, 0.04 part of modified nano zinc oxide, 1 part of green tea extract, 1 part of licorice extract, and 8 parts of purified water; the conditioning agent also includes modified nano sodium alginate; the weight ratio of the modified nano sodium alginate to lactic acid is 0.5:1; the modified nano sodium alginate is obtained by modifying the surface of nano sodium alginate with anti-adversity peptides, and the nano size of the modified nano sodium alginate is 80-120 nm, and the specific surface area is 120-150 m 2 / g. The preparation method of the modified nano-sodium alginate and modified nano-zinc oxide in this embodiment is consistent with that in Example 1. The preparation method of a conditioning agent for improving crop stress resistance in this embodiment is consistent with that in Example 1.

[0072] Example 3: This example discloses a conditioning agent for improving crop stress resistance, comprising the following raw materials in parts by weight: 0.5 parts of plant hormone, 3 parts of trehalose, 3 parts of humic acid, 1 part of composite bacterial agent, 2 parts of lactic acid, 0.1 parts of modified nano zinc oxide, 2 parts of green tea extract, 2 parts of licorice extract, and 10 parts of purified water; the conditioning agent also includes modified nano sodium alginate; the weight ratio of the modified nano sodium alginate to lactic acid is 0.5:2; the modified nano sodium alginate is obtained by modifying the surface of nano sodium alginate with anti-adversity peptides, and the nano size of the modified nano sodium alginate is 80-120 nm, and the specific surface area is 120-150 m 2 / g. The preparation method of the modified nano-sodium alginate and modified nano-zinc oxide in this embodiment is consistent with that in Example 1. The preparation method of a conditioning agent for improving crop stress resistance in this embodiment is consistent with that in Example 1.

[0073] Control group 1: This embodiment differs from embodiment 1 in that modified nano sodium alginate is not contained. This embodiment discloses a conditioning agent for improving crop stress resistance, comprising the following raw materials in parts by weight: 0.3 parts of plant hormones, 2 parts of trehalose, 2 parts of humic acid, 0.5 parts of composite bacterial agent, 1.5 parts of lactic acid, 0.07 parts of modified nano zinc oxide, 1.5 parts of green tea extract, 1.5 parts of licorice extract, and 9 parts of purified water. The preparation method of modified nano zinc oxide in this embodiment is consistent with that in embodiment 1. The preparation method of a conditioning agent for improving crop stress resistance in this embodiment is consistent with that in embodiment 1.

[0074] Control group 2: This embodiment differs from embodiment 1 in that modified nano zinc oxide is not contained. This embodiment discloses a conditioning agent for improving crop stress resistance, comprising the following raw materials in parts by weight: 0.3 parts of plant hormone, 2 parts of trehalose, 2 parts of humic acid, 0.5 parts of composite bacterial agent, 1.5 parts of lactic acid, 1.5 parts of green tea extract, 1.5 parts of licorice extract, and 9 parts of purified water; the conditioning agent also includes modified nano sodium alginate, wherein the weight ratio of the modified nano sodium alginate to lactic acid is 0.5:1.5, and the modified nano sodium alginate is obtained by modifying the surface of nano sodium alginate with anti-adversity peptides, and the nano size of the modified nano sodium alginate is 80-120 nm, and the specific surface area is 120-150 m 2 / g. The preparation method of the modified nano-sodium alginate in this embodiment is consistent with that in Example 1. The preparation method of a conditioning agent for improving crop stress resistance in this embodiment is consistent with that in Example 1.

[0075] Control group 3: The difference between this embodiment and embodiment 1 is that lactic acid is not contained. This embodiment discloses a conditioning agent for improving crop stress resistance, comprising the following raw materials in parts by weight: 0.3 parts of plant hormones, 2 parts of trehalose, 2 parts of humic acid, 0.5 parts of composite bacterial agent, 0.07 parts of modified nano zinc oxide, 1.5 parts of green tea extract, 1.5 parts of licorice extract, and 9 parts of purified water; the conditioning agent also includes modified nano sodium alginate, the modified nano sodium alginate and lactic acid are in a weight ratio of 0.5:1.5, the modified nano sodium alginate is obtained by modifying the surface of nano sodium alginate with anti-adversity peptides, the nano size of the modified nano sodium alginate is 80-120nm, and the specific surface area is 120-150m 2 / g. The preparation method of the modified nano-sodium alginate and modified nano-zinc oxide in this embodiment is consistent with that in Example 1. The preparation method of a conditioning agent for improving crop stress resistance in this embodiment is consistent with that in Example 1.

[0076] Effect evaluation: Rice growth promotion experiment: Select mature and healthy rice seeds, remove impurities on the seed surface through pretreatment, and then soak the rice seeds in clean water for 18-24 hours to promote germination. The size of the culture pot is 50cm×45cm, with a total of 21 pots, 3 pots in each experimental group, and 10 rice seeds in each pot. During the cultivation process, the conditioner is sprayed once every 7 days, with a spraying amount of 20ml. The blank group is sprayed with 20ml purified water, watered regularly, and a unified irrigation and topdressing system is adopted to ensure that the other planting management conditions are completely consistent. The test period is 30 days. The plant height is measured with a ruler every 10 days. The plant height is the distance from the base of the stem to the heart leaf. After the experiment, the length of the rice root system is measured with a ruler, the chlorophyll content is measured using a SPAD instrument, and the leaf area is measured using a leaf area meter. All values ​​are recorded as the average value of each experimental group.

[0077] Table 1 Statistical results of rice seed growth in each experimental group

[0078]

[0079] Table 1 is the statistical results of the growth of rice seeds in each experimental group. Plant height is an important indicator for measuring crop growth, reflecting the overall growth potential and growth rate of the crop; root length reflects the development and growth capacity of the crop root system, and a longer root system usually means that the crop has better water and nutrient absorption capacity; chlorophyll content is a direct reflection of the photosynthetic capacity of the crop, and a high chlorophyll content usually means that the photosynthetic efficiency of the crop is high and it can produce nutrients more efficiently; leaf area reflects the photosynthetic potential of the crop, and crops with a larger leaf area usually have a stronger photosynthetic capacity and can synthesize more organic matter. As can be seen from Table 1, there are differences in the growth of rice seeds in each experimental group, and the growth index values ​​of the blank group rice seeds are the lowest. By comparing the growth of rice seeds in Examples 1 to 3 with those in Control Groups 1 to 3, it can be found that, overall, the growth of rice seeds in Examples 1 to 3 is better, among which the growth of rice seeds in Example 1 is the best, and the plant height reaches 33.5 cm after the test period, the root length is 28.3 cm, the chlorophyll content is 44.6, and the leaf area is 18.5 cm 2 By comparing Example 1 with Control Groups 1 to 3, it can be found that when the three substances of modified nano-alginate sodium, modified nano-zinc oxide and lactic acid are simultaneously present in the conditioner, spraying it during the crop cultivation process can effectively promote crop growth.

[0080] Salt-alkali stress experiment: Preparation of salt-alkali solution: Use purified water to prepare a salt-alkali mixed solution (NaCl and NaHCO 3 ), the concentrations were set to 0, 50mMNaCl+25mMNaHCO 3 , 100mMNaCl+50mM NaHCO 3, 150mMNaCl+75mMNaHCO 3 and 200 mM NaCl + 100 mM NaHCO 3 A total of 5 concentration gradients are placed in a ground-mouth bottle for standby use. Select mature and healthy rice seeds, remove impurities on the seed surface by pretreatment, and then soak the rice seeds in clean water for 18 to 24 hours to promote germination. The culture pot size is 50cm×45cm, with a total of 15 pots, 3 pots in each experimental group, and 10 rice seeds in each pot. At the beginning of cultivation, the saline-alkali mixed solution of different concentrations is sprayed in the culture pot to simulate different degrees of saline-alkali environment, and the spraying amount is 10mL. During the cultivation process, the conditioning agent prepared in Example 1 is sprayed once every 7d, and the spraying amount is 20ml. Water regularly, adopt a unified irrigation and topdressing system, and ensure that the remaining planting management conditions are completely consistent. The test period is 30 days, and the plant height is measured with a ruler every 10 days. The plant height is the distance from the base of the stem to the heart leaf. After the experiment, the length of the rice root system is measured with a ruler, the chlorophyll content is measured by a SPAD instrument, and the leaf area is measured by a leaf area measuring instrument. All values ​​record the average value of each experimental group.

[0081] Table 2 Statistical results of rice seed growth in each experimental group under saline-alkali stress

[0082]

[0083] Table 2 shows the statistical results of the growth of rice seeds sprayed with the conditioning agent prepared in Example 1 under the stress of different concentrations of saline-alkali mixed solutions. It can be seen from Table 2 that under saline-alkali stress, as the concentration increases, the growth index values ​​of rice seeds show a downward trend, but each growth index is still at a high level. After the test period, the plant height is 28.8-33.5 cm, the root length is 26.8-28.2 cm, the chlorophyll content is 41.8-44.6, and the leaf area is 16.1-18.5 cm. 2 It can be seen that when the conditioning agent prepared in Example 1 is sprayed on rice seeds, the rice seeds show excellent salt-alkali resistance.

[0084] Through the above limited experiments, the application effect of a conditioner for improving crop stress resistance in Example 1 of the present invention is significant. By optimizing the formula of the conditioner, modified nano sodium alginate, modified nano zinc oxide and lactic acid are added during the production process to enhance the bioavailability of the conditioner, improve the microbial environment of the crop root system, and effectively activate the immune defense system of the crop, stimulating the crop to produce more disease-resistant and stress-resistant proteins. The modified nano zinc oxide enhances the absorption of nutrients by the root cells of the crop, assists in the activation of the crop immune system, synergistically enhances the disease resistance and stress resistance of the crop, and promotes the growth of the crop, thereby improving its disease resistance, drought resistance and salt-alkali resistance. Lactic acid effectively stabilizes the pH value of the conditioner, while alleviating the oxidative stress of the crop under adverse conditions, enhancing the physiological stability of the crop, and ultimately achieving the purpose of improving crop yield and quality.

[0085] Finally, it should be noted that: Although the present invention has been described in detail with reference to the aforementioned embodiments, it is still possible for those skilled in the art to modify the technical solutions described in the aforementioned embodiments, or to make equivalent substitutions for some of the technical features therein. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A conditioning agent for improving crop stress resistance, characterized in that: The invention comprises the following raw materials in parts by weight: 0.1-0.5 parts of plant hormone, 1-3 parts of trehalose, 1-3 parts of humic acid, 0.1-1 parts of composite bacterial agent, 1-2 parts of lactic acid, 0.04-0.1 parts of modified nano zinc oxide, 1-2 parts of green tea extract, 1-2 parts of licorice extract, and 8-10 parts of purified water; The conditioning agent also includes: Modified nano-alginate; The modified nano-sodium alginate and lactic acid are in a weight ratio of 0.5:(1-2); The modified nano-alginate is obtained by modifying the surface of nano-alginate with anti-adverse peptides. The nano-size of the modified nano-alginate is 80-120 nm, and the specific surface area is 120-150 m 2 / g.

2. A conditioning agent for improving crop stress resistance according to claim 1, characterized in that: The preparation method of the modified nano sodium alginate comprises: S11. Sodium alginate was dissolved in purified water under stirring, and calcium chloride was slowly added after stirring for 0.5 to 1 h, with the drop rate controlled at 1 to 2 drops / s, while the temperature was raised to 45 to 55°C, and stirring was continued for 2 to 3 h to obtain a first mixed solution; S12. The first mixed solution was allowed to stand for 4 to 6 hours and then the solid-liquid separation was performed. The separated solid was washed five times with purified water and then placed in a vacuum drying oven for drying at a temperature of 70 to 80 ° C for a drying time of 12 to 18 hours to obtain nano-sodium alginate and ground into a powder for standby use; S13. Dissolve the nano-sodium alginate in dichloromethane under stirring, add N-hydroxysuccinimide and 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride in sequence after stirring for 1 to 2 hours, and continue stirring for 4 to 6 hours to obtain a second mixed solution; S14. dissolving the anti-adverse peptide in phosphate buffered saline and stirring for 1 to 2 hours until fully dissolved to obtain an anti-adverse peptide solution, slowly dropping the second mixed solution into the anti-adverse peptide solution and reacting for 18 to 24 hours to obtain a third mixed solution; S15. The third mixed solution is subjected to high-speed centrifugation at a rotation speed of 10,000 to 12,000 rpm for 15 to 20 min. The separated solid is washed alternately with phosphate buffered saline and purified water for 3 times and then vacuum dried at a drying temperature of 40 to 50° C. After drying for 12 to 14 hours, the modified nano-sodium alginate is obtained and ground into powder for later use.

3. A conditioning agent for improving crop stress resistance according to claim 2, characterized in that: The mass ratio of the sodium alginate, calcium chloride and anti-adversity peptide is 1:(1-2):(0.02-0.05).

4. A conditioning agent for improving crop stress resistance according to claim 1, characterized in that: The plant hormone is a compound of gibberellin, cytokinin and abscisic acid, and the weight ratio of gibberellin, cytokinin and abscisic acid is (1-2): (0.5-1): (0.5-1).

5. A conditioning agent for improving crop stress resistance according to claim 1, characterized in that: The composite bacterial agent is a compound of nitrogen-fixing bacteria, root-promoting bacteria and Bacillus subtilis, wherein the weight ratio of the nitrogen-fixing bacteria, root-promoting bacteria and Bacillus subtilis is (1-2): (0.5-1): (0.1-0.5).

6. A conditioning agent for improving crop stress resistance according to claim 1, characterized in that: The preparation method of the modified nano zinc oxide comprises: S21. Dispersing zinc oxide in anhydrous ethanol under nitrogen protection and subjecting to ultrasonic treatment at an ultrasonic frequency of 40 to 50 kHz, 3-aminopropyltriethoxysilane was slowly added to reflux at room temperature for 0.5 to 1 h, and the reflux temperature was 75 to 80 ° C. After reflux for 6 to 8 h, a fourth mixed solution was obtained; S22. The fourth mixed solution was subjected to high-speed centrifugation at a speed of 8000 to 10000 rpm for 15 to 20 min. The separated solid was washed three times with anhydrous ethanol and then vacuum dried at a drying temperature of 45 to 55 ° C. After drying for 8 to 12 h, the nano zinc oxide intermediate was ground into a powder for standby use. S23. Dissolve polyvinyl alcohol in anhydrous ethanol under stirring, stir for 1 to 2 hours, slowly add 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride and N-hydroxysuccinimide, raise the temperature to 45 to 60° C., continue stirring for 4 to 6 hours to obtain a fifth mixed solution; S24. Disperse the nano zinc oxide intermediate in anhydrous ethanol under light protection and nitrogen protection, slowly add the fifth mixed solution after stirring for 0.5 to 1 hour, and continue stirring at room temperature for 24 to 28 hours to obtain a sixth mixed solution; S25. The sixth mixed solution is subjected to high-speed centrifugation at a rotation speed of 10,000 to 12,000 rpm for 15 to 20 minutes. The separated solid is washed with anhydrous ethanol 5 times and then vacuum dried at a drying temperature of 40 to 50° C. After drying for 12 to 14 hours, the modified nano zinc oxide is obtained and ground into powder for later use.

7. A conditioning agent for improving crop stress resistance according to claim 6, characterized in that: The modified nano zinc oxide is obtained by grafting polyvinyl alcohol on the surface of nano zinc oxide. The nano size of the modified nano zinc oxide is 40-60 nm, and the specific surface area is 120-150 m 2 / g.

8. A method for preparing a conditioning agent for improving crop stress resistance, which is used for preparing the conditioning agent as claimed in any one of claims 1 to 7, characterized in that: The method comprises the following steps: S31. Add trehalose and humic acid to purified water in a container and stir thoroughly. After stirring for 1 to 2 hours, perform ultrasonic treatment at an ultrasonic frequency of 40 to 50 kHz and an ultrasonic temperature of 40 to 50 ° C. After 0.5 to 1 hour of ultrasonic treatment, a seventh mixed solution is obtained; S32. Under stirring, the modified nano-alginate sodium, modified nano-zinc oxide, lactic acid, green tea extract and licorice extract were added to the seventh mixed solution in sequence and stirred evenly, the stirring speed was 400 to 600 rpm, the stirring temperature was 45 to 55 ° C, and the mixture was ultrasonically treated for 2 to 4 hours at an ultrasonic frequency of 40 to 50 kHz for 0.5 to 1 hour to obtain an eighth mixed solution; S33. After the eighth mixed solution is cooled to room temperature, the plant hormone and the composite bacterial agent are dissolved in purified water and sprayed evenly on the eighth mixed solution, and stirred again for 0.5 to 1 h and filtered through a 0.22 μm filter membrane to obtain a conditioning agent; S34. Transfer the conditioner to a clean, dry storage container and store it in a dark place at a low temperature of 4 to 10°C.

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