A cultivation substrate for enhancing stress resistance of strawberry, a cultivation method and application thereof

Abstract

The application discloses a kind of cultivation matrix of enhancing the cultivation method and application of resistance of strawberry, including main material and additive, the main material includes peat, coconut bran, perlite, mixed fermentation compost, the additive includes modified silicon dioxide, modified iron manganese oxide nanocolloid, chitosan quaternary ammonium salt and calcium sulfate.Modified silicon dioxide will mobility extremely poor calcium fixed inside carrier, and store iron by chelation, prevent calcium, iron fixed or leaching in matrix.Modified iron manganese oxide nanocolloid is driven by coulomb force in matrix positive field, electrophoretic migration, migrate to root surface, drag the modified silicon dioxide covalently bonded with it, and calcium, iron is released to root system disease risk area in modified silicon dioxide in root system under the joint action of chitosan quaternary ammonium salt and calcium sulfate dihydrate, the migration rate of modified iron manganese oxide nanocolloid is enhanced.

Description

TECHNICAL FIELD

[0001] The application belongs to the field of strawberry planting, and particularly relates to a cultivation substrate for enhancing the stress resistance of strawberries, a cultivation method and application. BACKGROUND

[0002] Strawberry is a shallow-rooted crop, and the root system is mainly distributed in the surface layer of the substrate within 15-20 cm, with few lateral roots and low root hair density, resulting in weak absorption capacity and being easily affected by environmental fluctuations, especially for elements such as calcium and iron with poor mobility, the root system is insufficient in absorption, and intermittent deficiency symptoms are easily caused, resulting in problems such as strawberry collar rot, abnormal plant growth and serious decline in fruit quality. At present, high-frequency water and fertilizer supply is often used to maintain the nutrient concentration, which not only causes a large consumption of manpower and material resources, but also may accelerate soil acidification. SUMMARY

[0003] (1) Technical problem to be solved

[0004] The purpose of the present application is to provide a cultivation substrate for enhancing the stress resistance of strawberries, a cultivation method and application, so as to solve the problem of weak absorption capacity of strawberries for elements such as calcium and iron with poor mobility, and to improve the fruit quality of strawberries.

[0005] (2) Technical scheme

[0006] To achieve the above-mentioned purpose, on the one hand, the present application provides a cultivation substrate for enhancing the stress resistance of strawberries, which comprises a main material and an additive, and the main material comprises the following components in parts by weight: peat 50-80 parts, coconut husk 30-60 parts, perlite 20-50 parts, and mixed fermented compost 10-20 parts.

[0007] The additive comprises modified silicon dioxide, modified iron-manganese oxide nanocolloid, chitosan quaternary ammonium salt and calcium sulfate dihydrate.

[0008] The modified silicon dioxide is covalently crosslinked with carboxymethyl chitosan after aminization of mesoporous silicon dioxide, and ethylenediamine di-o-hydroxyphenyl acetic acid is embedded in the mesoporous.

[0009] The modified iron-manganese oxide nanocolloid has a composite layer structure, and comprises a core layer, an intermediate layer and a signal response layer from inside to outside. The core layer is a citric acid modified iron-manganese oxide nanocolloid, the intermediate layer is a polydopamine film loaded with chitinase, and the signal response layer is polydopamine.

[0010] Further, the preparation method of the modified silicon dioxide comprises the following steps:

[0011] S11. Dissolve 3-aminopropyltriethoxysilane in anhydrous ethanol, add mesoporous silica nanoparticles, ultrasonic dispersion, stirring reaction under nitrogen protection, centrifugal separation, ethanol washing, vacuum drying, to obtain the first compound;

[0012] S12. Dissolve carboxymethyl chitosan in acetic acid buffer solution, add the first compound, carbodiimide crosslinking agent, stirring reaction, centrifugal washing, freeze-drying, to obtain the second compound;

[0013] S13. Disperse the second compound in an ethanolic solution of ethylenediamine di-o-hydroxyphenyl acetic acid, oscillate the reaction, centrifuge, vacuum dry, to obtain the modified silica.

[0014] Further, the preparation method of the modified iron-manganese oxide nanocolloid comprises the following steps:

[0015] S21. Mix FeCl3·6H2O with KMnO4, drop in ammonia water to adjust pH, water bath reaction, centrifugal collection of precipitate, washing to neutral, dispersion in deionized water, add citric acid, ultrasonic oscillation, centrifugal collection of precipitate, freeze-drying, to obtain the third compound;

[0016] S22. Dissolve chitinase in phosphate buffer to obtain a chitinase solution, disperse the third compound in a dopamine hydrochloride solution, oscillate to form a polydopamine thin layer, add the chitinase solution, stand for adsorption, centrifugal washing, to obtain the fourth compound;

[0017] S23. Ultrasonic dispersion of the fourth compound in an ammonium molybdate solution, vacuum impregnation, freeze solidification, add dopamine-Tris solution, oscillate the reaction, centrifugal washing, vacuum drying, to obtain the fifth compound;

[0018] S24. Disperse the fifth compound in an ethanolic solution of aminopropyltriethoxysilane, reflux reaction, centrifugal washing, vacuum drying, to obtain the modified iron-manganese oxide nanocolloid.

[0019] Based on the same inventive concept, in a second aspect, the present application also provides a cultivation method of a cultivation substrate for enhancing the stress resistance of strawberries, applied to the cultivation substrate for enhancing the stress resistance of strawberries, comprising the following steps:

[0020] S1. Prepare raw materials: dissolve chitosan quaternary ammonium salt in deionized water to prepare a 2% chitosan quaternary ammonium salt solution, mix the modified silica and the modified iron-manganese oxide nanocolloid in a Tris buffer, oscillate the reaction, centrifugal purification, centrifugal washing with deionized water, vacuum drying, to obtain a first mixture;

[0021] S2. Main substrate mixture: place the main material and calcium sulfate dehydrate in a blender, spray in the chitosan quaternary ammonium salt solution while stirring, mix until uniform, stand for adsorption, to obtain a second mixture;

[0022] S3. Preparing the cultivation substrate: uniformly spraying deionized water into the second mixture, adjusting the water content, covering the breathable film for maturation, and obtaining the cultivation substrate;

[0023] S4. Layered laying: placing the cultivation substrate in the substrate groove, uniformly scattering the first mixture above it, and laying the drip irrigation pipe.

[0024] Further, the modified silicon dioxide and the modified iron-manganese oxide nanocolloid are mixed at a mass ratio of 1.5-2:1.

[0025] Further, the mass of the chitosan quaternary ammonium salt solution accounts for 3-4% of the main material, the mass of the calcium sulfate dehydrate accounts for 2-3% of the main material, and the mass of the first mixture accounts for 5-7% of the main material.

[0026] Based on the same inventive concept, in a third aspect, the application also provides an application of the cultivation substrate or the cultivation method for enhancing the stress resistance of strawberries in improving the yield and quality of strawberries.

[0027] The modified silicon dioxide fixes the poor mobility of calcium inside the carrier and stores iron through chelation, preventing the fixation or loss of calcium and iron in the substrate. The carboxyl group of carboxymethyl chitosan and the amino group of the amino-modified silicon dioxide are covalently cross-linked to form a gel layer, which utilizes the -COO - chelates Ca 2+ . The ethylenediamine di-o-hydroxyphenyl acetic acid is embedded in the mesoporous, and the o-diphenol group is combined with Fe 3+ to form a hexadentate chelate, and the selectivity is prior to Ca 2+ and Mg 2+ .

[0028] The modified iron-manganese oxide nanocolloid is modified by citric acid, the intermediate layer is a polydopamine film loaded with chitinase, the signal response layer is polydopamine, and amino positive ions are introduced in the signal response layer through aminopropyl triethoxysilane. Because the surface of the strawberry root system is negatively charged, the modified iron-manganese oxide nanocolloid electrophoretically migrates towards the root system, the quinone group on the surface layer of the shell polydopamine of the modified iron-manganese oxide nanocolloid reacts with the amino group on the surface of the modified silicon dioxide to form a covalent bond, so that the modified silicon dioxide is also attracted to move towards the root system. The strawberry root system secretes H + and ascorbic acid and laccase, so that the polydopamine swells, the imine bond breaks, the ascorbic acid reduces the Mn 4+ and Fe 3+ of the modified iron-manganese oxide nanocolloid, causing the colloid to disintegrate and release citric acid and chitinase. The citric acid competes with the Ca 2+ and Fe 3+ in the soil adsorbed by the modified silicon dioxide, triggering the modified silicon dioxide to release Ca2+ and Fe 3+ , and then the Ca 2+ and Fe 3+ are enriched in the strawberry root system and the absorption of the root system is enhanced. In addition, since the pathogenic fungi secrete chitin in the rhizosphere, the released chitinase hydrolyzes the chitin into N-acetylglucosamine, which forms a high concentration area as a signal molecule at the fungal infection point, induces the migration of iron-manganese oxide nanocolloids to the disease risk area, and then the modified silicon dioxide releases the Ca 2+ and Fe 3+ to the disease risk area.

[0029] In addition, chitosan quaternary ammonium salt and calcium sulfate dihydrate are added to the strawberry cultivation substrate. The quaternary ammonium group of the chitosan quaternary ammonium salt is permanently positively charged in the strawberry substrate environment, strongly adsorbed on the substrate organic matter or metal oxide surface, and the positive charge density of the substrate is enhanced. The modified iron-manganese oxide nanocolloid positively charged group repels the positive charge of the chitosan quaternary ammonium salt, further enhancing the migration rate of the modified iron-manganese oxide nanocolloid to the negatively charged root system. The Ca 2+ of the calcium sulfate dihydrate forms an ionic bridge with the -COO - on the surface of the modified silicon dioxide, so that the apparent charge is reduced, thereby reducing the electrostatic repulsion between the modified silicon dioxide and the root system.

[0030] In summary, due to the adoption of the above technical solutions, the beneficial effects of the present application are:

[0031] 1. The modified silicon dioxide fixes the poor mobility of calcium in the carrier and stores iron through chelation, preventing the fixation or loss of calcium and iron in the substrate.

[0032] 2. The modified iron-manganese oxide nanocolloid is driven by the coulomb force in the positive electric field of the substrate, electrophoretic migration, migration to the root surface, and traction of the modified silicon dioxide covalently bonded thereto. The degradation of the modified iron-manganese oxide nanocolloid shell in the root system releases calcium and iron to the disease risk area of the root system under the action of citric acid and chitinase.

[0033] 3. Under the joint action of chitosan quaternary ammonium salt and calcium sulfate dihydrate, the migration rate of the modified iron-manganese oxide nanocolloid and the modified silicon dioxide is enhanced. BRIEF DESCRIPTION OF DRAWINGS

[0034] Figure 1 The cultivation method flowchart for enhancing the stress resistance of strawberries in Example 1 of the present application. DETAILED DESCRIPTION

[0035] With reference to the accompanying drawings, the technical solutions in the embodiments of the present application will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of the present application. Embodiment 1

[0036] The embodiment discloses a cultivation substrate for enhancing the stress resistance of strawberries, which comprises a main material and an additive, wherein the main material comprises the following components in parts by weight: 50 parts of peat, 30 parts of coconut husk, 20 parts of perlite and 10 parts of mixed fermented compost;

[0037] The additive comprises modified silicon dioxide, modified iron-manganese oxide nanocolloid, chitosan quaternary ammonium salt and calcium sulfate dihydrate.

[0038] The modified silicon dioxide is covalently crosslinked with carboxymethyl chitosan after amination of mesoporous silicon dioxide, and ethylenediamine di-o-hydroxyphenyl acetic acid is embedded in the mesoporous.

[0039] The modified iron-manganese oxide nanocolloid has a composite layer structure, and comprises a core layer, an intermediate layer and a signal response layer from inside to outside. The core layer is a citric acid modified iron-manganese oxide nanocolloid, the intermediate layer is a polydopamine film loaded with chitinase, and the signal response layer is polydopamine.

[0040] The preparation method of the modified silicon dioxide comprises the following steps:

[0041] S11. 10 mL of 3-aminopropyltriethoxysilane is dissolved in 100 mL of anhydrous ethanol, 2 g of mesoporous silicon dioxide nanoparticles are added, ultrasonic dispersion is performed, stirring reaction is carried out at 60 DEG C under nitrogen protection for 6 hours, centrifugal separation is performed, ethanol washing is performed, vacuum drying is performed, and a first compound is obtained.

[0042] S12. 0.25 g of carboxymethyl chitosan is dissolved in 17 mL of an acetic acid buffer solution, 0.7 g of the first compound and 0.05 g of a carbodiimide crosslinking agent are added, stirring reaction is carried out at room temperature for 12 hours, the solid is collected by centrifugation, deionized water washing is performed, and freeze-drying is performed to obtain a second compound.

[0043] S13. 1 g of the second compound is dispersed in 40 mL of an ethanol solution of ethylenediamine di-o-hydroxyphenyl acetic acid, 60 DEG C oscillation reaction is carried out for 24 hours, centrifugation is performed, and vacuum drying is performed to obtain modified silicon dioxide.

[0044] The preparation method of the modified iron-manganese oxide nanocolloid comprises the following steps:

[0045] S21. 8g FeCl3·6H2O was dissolved in 300mL deionized water to obtain a FeCl3·6H2O solution, 0.8g KMnO4 was dissolved in 100mL deionized water to obtain a KMnO4 solution, the FeCl3·6H2O solution and the KMnO4 solution were mixed, ammonia water was added dropwise to adjust pH = 8.0, 80℃ water bath reaction for 2 hours, centrifugal collection of precipitate, deionized water washing to neutral, dispersed in 100mL deionized water, 5g citric acid was added, ultrasonic oscillation at 60℃ for 3 hours, centrifugal collection of precipitate, freeze-drying to obtain a third compound;

[0046] S22. 10mg chitinase was dissolved in 10mL phosphate buffer to obtain a chitinase solution, 100mg third compound was dispersed in 50mL 2g / L dopamine hydrochloride solution, oscillation to form a polydopamine thin layer, 10mL chitinase solution was added, 4℃ static adsorption for 24 hours, centrifugal collection of solid, deionized water washing to obtain a fourth compound;

[0047] S23. 100mg fourth compound was ultrasonic dispersed in 10mL ammonium molybdate solution, vacuum impregnation, freeze solidification, 100mL dopamine-Tris solution was added, oscillation reaction for 6 hours, centrifugal collection of solid, deionized water washing, vacuum drying to obtain a fifth compound;

[0048] S24. 50mg fifth compound was dispersed in 40mL amino propyl triethoxysilane ethanol solution, 60℃ reflux reaction for 4 hours, centrifugal collection of solid, deionized water washing, vacuum drying to obtain a modified iron manganese oxide nanocolloid.

[0049] It should be noted that, the modified iron manganese oxide nanocolloid is coated by polydopa twice, on the one hand, the shielding of the negative electricity of the inner layer citric acid by polydopa is greatly enhanced, on the other hand, the intermediate layer polydopa loads chitinase, the outer layer polydopa protects the chitinase in the intermediate layer from being released too early, and the outer layer polydopa introduces amino positive ions, so that the modified iron manganese oxide nanocolloid is electrostatically attracted to the negatively charged roots.

[0050] The cultivation method of the cultivation substrate for enhancing the stress resistance of strawberries comprises the following steps:

[0051] S1. Preparation of raw materials: dissolve chitosan quaternary ammonium salt in deionized water to prepare a 2% chitosan quaternary ammonium salt solution, mix the modified silicon dioxide and the modified iron manganese oxide nanocolloid in Tris buffer, oscillation reaction, centrifugal purification, deionized water centrifugal washing, vacuum drying to obtain a first mixture;

[0052] S2. Main substrate mixture: the main material and calcium sulfate dihydrate are placed in a blender, and the chitosan quaternary ammonium salt solution is sprayed while stirring, mixed until uniform, and then static adsorption to obtain a second mixture;

[0053] S3. Preparing the cultivation substrate: uniformly spraying deionized water into the second mixture, adjusting the water content, covering the breathable film for maturation, and obtaining the cultivation substrate.

[0054] S4. Layered laying: placing the cultivation substrate in the substrate groove, uniformly scattering the first mixture above it, and laying the drip irrigation pipe.

[0055] It should be noted that, as shown in Figure 1, the shell polydopamine layer of the modified iron-manganese oxide nanocolloid is reacted with the amino group on the surface of the modified silicon dioxide to form a C-N bond through Michael addition reaction and an imine bond (C=N) through Schiff base reaction to prepare the first mixture. The cultivation method of layered laying is adopted in the present application, and the first mixture is laid above the cultivation substrate. When the drip irrigation pipe is opened, the first mixture moves with the irrigation water to the inside of the cultivation substrate. The modified silicon dioxide in the first mixture adsorbs calcium and iron with poor mobility in the substrate, and the modified iron-manganese oxide nanocolloid in the first mixture has a positive electric group, so that the first mixture migrates to the negatively charged root system.

[0056] It should be noted that, in order to prevent the first mixture from losing effectiveness, the first mixture is added every 40-60 days, uniformly scattered on the surface of the cultivation substrate, and flows into the substrate with the drip irrigation water to achieve continuous absorption of calcium and iron by the root system.

[0057] The modified silicon dioxide and the modified iron-manganese oxide nanocolloid are mixed in a mass ratio of 1.5:1.

[0058] The mass of the chitosan quaternary ammonium salt solution accounts for 3% of the main material, the mass of the calcium sulfate dihydrate accounts for 2% of the main material, and the mass of the first mixture accounts for 5% of the main material.

[0059] The application of the cultivation substrate or the cultivation method for enhancing the stress resistance of strawberries in improving the yield and quality of strawberries. Example 2

[0060] This example is based on Example 1, and differs from Example 1 in that it includes a main material and an additive. The main material includes the following components in parts by weight: peat 65 parts, coconut coir 45 parts, perlite 35 parts, and mixed fermented compost 15 parts.

[0061] The additive includes modified silicon dioxide, modified iron-manganese oxide nanocolloid, chitosan quaternary ammonium salt, and calcium sulfate dihydrate.

[0062] The other components and the preparation method are the same as in Example 1. Example 3

[0063] The embodiment is based on example 1, and different from example 1 is that the embodiment comprises a main material and an additive, wherein the main material comprises the following components in parts by weight: peat 80 parts, coconut husk 60 parts, perlite 50 parts, and mixed fermented humus 20 parts.

[0064] The additive comprises modified silicon dioxide, modified iron-manganese oxide nanocolloid, chitosan quaternary ammonium salt, and calcium sulfate dihydrate.

[0065] The other components and the preparation method are the same as those in example 1. Example 4

[0066] The embodiment is based on example 1, and different from example 1 is that the modified silicon dioxide and the modified iron-manganese oxide nanocolloid in the embodiment are mixed at a mass ratio of 2:1.

[0067] The other components and the preparation method are the same as those in example 1. Example 5

[0068] The embodiment is based on example 1, and different from example 1 is that the mass of the chitosan quaternary ammonium salt solution accounts for 3.5% of the main material, the mass of the calcium sulfate dihydrate accounts for 2.5% of the main material, and the mass of the first mixture accounts for 6% of the main material.

[0069] The other components and the preparation method are the same as those in example 1. Example 6

[0070] The embodiment is based on example 1, and different from example 1 is that the mass of the chitosan quaternary ammonium salt solution accounts for 4% of the main material, the mass of the calcium sulfate dihydrate accounts for 3% of the main material, and the mass of the first mixture accounts for 7% of the main material.

[0071] The other components and the preparation method are the same as those in example 1. Comparative example 1

[0072] The comparative example is based on example 1, and different from example 1 is that the modified silicon dioxide in the comparative example is not reacted with carboxymethyl chitosan.

[0073] The preparation method of the modified silicon dioxide comprises the following steps:

[0074] S11. 10 mL of 3-aminopropyltriethoxysilane is dissolved in 100 mL of anhydrous ethanol, 2 g of mesoporous silica nanoparticles is added, ultrasonic dispersion is performed, stirring reaction is performed at 60°C under nitrogen protection for 6 hours, centrifugal separation is performed, ethanol washing is performed, vacuum drying is performed, and a first compound is obtained;

[0075] S12. 1 g of the first compound was dispersed in 40 mL of an ethylenediamine di-o-hydroxyphenyl acetic acid ethanol solution, and oscillated at 60°C for 24 hours. After centrifugation and vacuum drying, the modified silica was obtained.

[0076] The other components and preparation methods were the same as in Example 1. Comparative Example 2

[0077] This comparative example was based on Example 1, except that the modified silica mesoporous in this comparative example did not embed ethylenediamine di-o-hydroxyphenyl acetic acid.

[0078] The preparation method of the modified silica included the following steps:

[0079] S11. 10 mL of 3-aminopropyltriethoxysilane was dissolved in 100 mL of anhydrous ethanol, 2 g of mesoporous silica nanoparticles was added, and ultrasonic dispersion was performed. After stirring at 60°C for 6 hours under nitrogen protection, centrifugal separation was performed, and ethanol washing and vacuum drying were performed to obtain the first compound.

[0080] S12. 0.25 g of carboxymethyl chitosan was dissolved in 17 mL of an acetic acid buffer solution, 0.7 g of the first compound and 0.05 g of a carbodiimide crosslinking agent were added, and stirring was performed at room temperature for 12 hours. After centrifugal collection of the solid, deionized water washing and freeze-drying, the modified silica was obtained.

[0081] The other components and preparation methods were the same as in Example 1. Comparative Example 3

[0082] This comparative example was based on Example 1, except that the modified iron-manganese oxide nanocolloid in this comparative example did not introduce amino positive ions.

[0083] The preparation method of the modified iron-manganese oxide nanocolloid included the following steps:

[0084] S21. 8 g of FeCl3·6H2O was dissolved in 300 mL of deionized water to obtain a FeCl3·6H2O solution, 0.8 g of KMnO4 was dissolved in 100 mL of deionized water to obtain a KMnO4 solution, the FeCl3·6H2O solution and the KMnO4 solution were mixed, ammonia water was added dropwise to adjust the pH to 8.0, and stirring was performed at 80°C for 2 hours. After centrifugal collection of the precipitate, deionized water washing until neutral, dispersion in 100 mL of deionized water, and the addition of 5 g of citric acid, ultrasonic oscillation was performed at 60°C for 3 hours. After centrifugal collection of the precipitate, freeze-drying was performed to obtain the third compound.

[0085] S22. 10 mg chitinase was dissolved in 10 mL phosphate buffer to obtain a chitinase solution, 100 mg of the third compound was dispersed in 50 mL of a 2 g / L dopamine hydrochloride solution, and a polydopamine thin layer was formed by oscillation. 10 mL of the chitinase solution was added, and adsorption was carried out at 4°C for 24 hours. The solid was collected by centrifugation, washed with deionized water, and a fourth compound was obtained;

[0086] S23. 100 mg of the fourth compound was ultrasonically dispersed in 10 mL of an ammonium molybdate solution, vacuum impregnated, frozen and solidified, 100 mL of a dopamine-Tris solution was added, and oscillation reaction was carried out for 6 hours. The solid was collected by centrifugation, washed with deionized water, and vacuum dried to obtain modified iron-manganese oxide nanocolloid.

[0087] The other components and preparation methods are the same as in Example 1. Comparative Example 4

[0088] This comparative example is based on Example 1, except that the modified iron-manganese oxide nanocolloid in this comparative example is not subjected to secondary coating.

[0089] The preparation method of the modified iron-manganese oxide nanocolloid comprises the following steps:

[0090] S21. 8 g of FeCl3·6H2O was dissolved in 300 mL of deionized water to obtain a FeCl3·6H2O solution. 0.8 g of KMnO4 was dissolved in 100 mL of deionized water to obtain a KMnO4 solution. The FeCl3·6H2O solution and the KMnO4 solution were mixed, ammonia water was added dropwise to adjust the pH to 8.0, and reaction was carried out at 80°C for 2 hours. The precipitate was collected by centrifugation, washed with deionized water until neutral, dispersed in 100 mL of deionized water, and 5 g of citric acid was added. Ultrasonic oscillation was carried out at 60°C for 3 hours. The precipitate was collected by centrifugation and freeze-dried to obtain a third compound.

[0091] S22. 10 mg chitinase was dissolved in 10 mL phosphate buffer to obtain a chitinase solution, 100 mg of the third compound was dispersed in 50 mL of a 2 g / L dopamine hydrochloride solution, and a polydopamine thin layer was formed by oscillation. 10 mL of the chitinase solution was added, and adsorption was carried out at 4°C for 24 hours. The solid was collected by centrifugation, washed with deionized water, and a fourth compound was obtained;

[0092] S23. 50 mg of the fourth compound was dispersed in 40 mL of an aminopropyltriethoxysilane ethanol solution, and reflux reaction was carried out at 60°C for 4 hours. The solid was collected by centrifugation, washed with deionized water, and vacuum dried to obtain modified iron-manganese oxide nanocolloid.

[0093] The other components and preparation methods are the same as in Example 1. Comparative Example 5

[0094] The comparative example is based on example 1, and different from example 1 is that the modified iron-manganese oxide nanocolloid of the comparative example has no intermediate layer.

[0095] The preparation method of the modified iron-manganese oxide nanocolloid comprises the following steps:

[0096] S21. 8 g of FeCl3·6H2O was dissolved in 300 mL of deionized water to obtain a FeCl3·6H2O solution, 0.8 g of KMnO4 was dissolved in 100 mL of deionized water to obtain a KMnO4 solution, the FeCl3·6H2O solution and the KMnO4 solution were mixed, ammonia water was added dropwise to adjust pH to 8.0, and the mixture was reacted in a water bath at 80°C for 2 hours. The precipitate was collected by centrifugation, washed with deionized water until neutral, dispersed in 100 mL of deionized water, 5 g of citric acid was added, and the mixture was ultrasonically shaken at 60°C for 3 hours. The precipitate was collected by centrifugation and freeze-dried to obtain a third compound;

[0097] S22. 100 mg of the third compound was ultrasonically dispersed in 10 mL of an ammonium molybdate solution, vacuum impregnated, and freeze solidified. 100 mL of a dopamine-Tris solution was added, and the mixture was shaken for 6 hours. The solid was collected by centrifugation, washed with deionized water, and vacuum dried to obtain a sixth compound;

[0098] S23. 50 mg of the sixth compound was dispersed in 40 mL of an ethanol solution of aminopropyltriethoxysilane, and the mixture was refluxed at 60°C for 4 hours. The solid was collected by centrifugation, washed with deionized water, and vacuum dried to obtain a modified iron-manganese oxide nanocolloid.

[0099] The other components and the preparation method are the same as those of example 1. Comparative example 6

[0100] The comparative example is based on example 1, and different from example 1 is that the core layer of the modified iron-manganese oxide nanocolloid of the comparative example is not modified with citric acid.

[0101] The preparation method of the modified iron-manganese oxide nanocolloid comprises the following steps:

[0102] S21. 8 g of FeCl3·6H2O was dissolved in 300 mL of deionized water to obtain a FeCl3·6H2O solution, 0.8 g of KMnO4 was dissolved in 100 mL of deionized water to obtain a KMnO4 solution, the FeCl3·6H2O solution and the KMnO4 solution were mixed, ammonia water was added dropwise to adjust pH to 8.0, and the mixture was reacted in a water bath at 80°C for 2 hours. The precipitate was collected by centrifugation, washed with deionized water until neutral, and freeze-dried to obtain a seventh compound;

[0103] S22. 10 mg chitinase was dissolved in 10 mL phosphate buffer to obtain a chitinase solution, 100 mg of the seventh compound was dispersed in 50 mL of a 2 g / L dopamine hydrochloride solution to form a polydopamine thin layer, 10 mL of the chitinase solution was added, and the mixture was placed at 4°C for 24 hours of adsorption, and then centrifuged to collect the solid, which was washed with deionized water to obtain an eighth compound;

[0104] S23. 100 mg of the eighth compound was ultrasonically dispersed in 10 mL of an ammonium molybdate solution, vacuum impregnated, frozen and solidified, 100 mL of a dopamine-Tris solution was added, and the mixture was shaken for 6 hours of reaction, and then centrifuged to collect the solid, which was washed with deionized water and vacuum dried to obtain a ninth compound;

[0105] S24. 50 mg of the ninth compound was dispersed in 40 mL of an ethanol solution of aminopropyl triethoxysilane, and the mixture was refluxed at 60°C for 4 hours of reaction, and then centrifuged to collect the solid, which was washed with deionized water and vacuum dried to obtain a modified iron-manganese oxide nanocolloid.

[0106] The other components and preparation methods are the same as those in Example 1. Comparative Example 7

[0107] The present comparative example is based on Example 1, and differs from Example 1 in that the present comparative example does not add modified silicon dioxide. The other components and preparation methods are the same as those in Example 1. Comparative Example 8

[0108] The present comparative example is based on Example 1, and differs from Example 1 in that the present comparative example does not add modified iron-manganese oxide nanocolloid. The other components and preparation methods are the same as those in Example 1. Comparative Example 9

[0109] The present comparative example is based on Example 1, and differs from Example 1 in that the present comparative example does not add chitosan quaternary ammonium salt. The other components and preparation methods are the same as those in Example 1. Comparative Example 10

[0110] The present comparative example is based on Example 1, and differs from Example 1 in that the present comparative example does not add calcium sulfate dihydrate. The other components and preparation methods are the same as those in Example 1. Comparative Example 11

[0111] The present comparative example is a blank control group.

[0112] The present comparative example discloses a cultivation substrate for enhancing the stress resistance of strawberries, which comprises the following raw materials in parts by weight: peat 50 parts, coconut husk 30 parts, perlite 20 parts, and mixed fermented humus 10 parts.

[0113] The cultivation method of the cultivation substrate for enhancing the stress resistance of strawberries comprises the following steps:

[0114] S1. Put the raw materials into a blender, mix until uniform, spray with deionized water, adjust the moisture content to 55-60%, cover with a breathable film, and mature at 25°C for 72 hours to obtain the cultivation substrate.

[0115] Test verification:

[0116] Strawberry pot experiment: strawberry variety is Hongyan, plant spacing is 20 cm, root system is completely buried in the cultivation substrate, and 10 plants are planted in each experimental group. During the strawberry planting process, the same watering and fertilization frequency and dosage are adopted.

[0117] 1. Collect the substrate of strawberry root system, and detect the concentrations of calcium and iron by ICP-MS. All values are recorded as the average of each experimental group.

[0118]

[0119] As shown in Table 1, the concentrations of calcium and iron in the cultivation substrate near the root system of strawberries in each test group are shown. By comparing Example 1 and Comparative Examples 1, 2, it can be seen that the modified silicon dioxide fixes the calcium with poor mobility inside the carrier and stores iron through ethylenediamine di-o-hydroxyphenyl acetic acid, preventing the fixation or loss of calcium and iron in the substrate. By comparing Example 1 and Comparative Example 3, the modified iron-manganese oxide nanocolloid without introducing a positive group is difficult to migrate to the root system in the substrate, resulting in low concentrations of calcium and iron in the root system. By comparing Example 1 and Comparative Example 4, the modified iron-manganese oxide nanocolloid is not coated twice, and only has a polydopamine protective layer, and the negative electricity of the citric acid in the core has a certain influence on the migration of the modified iron-manganese oxide nanocolloid to the root system. By comparing Example 1 and Comparative Example 5, it can be seen that when chitin is secreted in the root system where pathogenic fungi are active, chitin can be hydrolyzed into N-acetylglucosamine by chitinase, and N-acetylglucosamine as a signal molecule forms a high concentration area at the fungal infection site, inducing the modified iron-manganese oxide nanocolloid to migrate to the disease risk area, and further promoting the release of calcium and iron by the modified silicon dioxide. By comparing Example 1 and Comparative Example 6, it can be seen that citric acid can further enhance the release of calcium and iron by the modified silicon dioxide. By comparing Example 1 and Comparative Examples 7, 8, 9, and 10, it can be seen that the modified silicon dioxide, the negative charge of the modified iron-manganese oxide nanocolloid, the chitosan quaternary ammonium salt, and calcium sulfate dihydrate work synergistically, so that elements with poor mobility such as calcium and iron can migrate to the root system for release, and then promote the absorption of the root system.

[0120] 2. Harvest mature fruits, calculate the average yield per plant, and detect the sugar content and hardness of the fruits.

[0121]

[0122] As shown in Table 1 are the yield and quality of strawberry fruit, from the table can be seen, example 1 and comparative example 7, 8, 9, 10 contrast, the addition of additives modified silicon dioxide, modified iron manganese oxide nanocolloid, chitosan quaternary ammonium salt and calcium sulfate dihydrate, the yield of example 1 is higher, and the sugar content and hardness of strawberry quality is also better, mainly due to the addition of additives, the migration of strawberry root system to calcium, iron and other poor element absorption is greatly enhanced, and then the yield and quality of strawberry are improved.

[0123] The above only describes the preferred embodiments of the present application and is not intended to limit the protection scope of the present application, and any modification, equivalent replacement and improvement made by any person skilled in the art within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A cultivation substrate for enhancing stress resistance of strawberry, characterized by, The main material comprises the following components in parts by weight: peat 50-80 parts, coconut husk 30-60 parts, perlite 20-50 parts, and mixed fermented humus 10-20 parts; The additive comprises modified silicon dioxide, modified iron-manganese oxide nanocolloid, chitosan quaternary ammonium salt, and calcium sulfate dehydrate; The modified silicon dioxide is covalently crosslinked with carboxymethyl chitosan after being aminated, and embedded with ethylenediamine di-o-hydroxyphenyl acetic acid in mesopores; The modified iron-manganese oxide nanocolloid has a composite layer structure, and comprises a core layer, an intermediate layer, and a signal response layer from inside to outside; the core layer is a citric acid modified iron-manganese oxide nanocolloid, the intermediate layer is a polydopamine film loaded with chitinase, and the signal response layer is polydopamine; The modified silicon dioxide and the modified iron-manganese oxide nanocolloid are mixed in Tris buffer solution, oscillated for reaction, centrifuged for purification, washed with deionized water, and vacuum dried to obtain a first mixture; The modified silicon dioxide and the modified iron-manganese oxide nanocolloid are mixed at a mass ratio of 1.5-2:1; The mass of the chitosan quaternary ammonium salt solution accounts for 3-4% of the main material, the mass of the calcium sulfate dehydrate accounts for 2-3% of the main material, and the mass of the first mixture accounts for 5-7% of the main material.

2. The cultivation substrate for enhancing stress resistance of strawberry according to claim 1, wherein The preparation method of the modified silicon dioxide comprises the following steps: S11. 3-aminopropyltriethoxysilane is dissolved in anhydrous ethanol, mesoporous silicon dioxide nanoparticles are added, ultrasonic dispersion is performed, stirring reaction is performed under nitrogen protection, centrifugal separation is performed, ethanol washing is performed, and vacuum drying is performed to obtain a first compound; S12. Carboxymethyl chitosan is dissolved in acetic acid buffer solution, the first compound and a carbodiimide crosslinking agent are added, stirring reaction is performed, centrifugal washing is performed, and freeze-drying is performed to obtain a second compound; S13. The second compound is dispersed in an ethanol solution of ethylenediamine di-o-hydroxyphenyl acetic acid, oscillation reaction is performed, centrifugation is performed, and vacuum drying is performed to obtain modified silicon dioxide.

3. The cultivation substrate for enhancing stress resistance of strawberry according to claim 1, wherein The preparation method of the modified iron-manganese oxide nanocolloid comprises the following steps: S21. FeCl3·6H2O and KMnO4 are mixed, ammonia water is added dropwise to adjust pH, water bath reaction is performed, the precipitate is collected by centrifugation, washed to neutral, dispersed in deionized water, citric acid is added, ultrasonic oscillation is performed, the precipitate is collected by centrifugation, and freeze-drying is performed to obtain a third compound; S22. Chitinase is dissolved in a phosphate buffer solution to obtain a chitinase solution, the third compound is dispersed in a dopamine hydrochloride solution, a polydopamine film is formed by oscillation, the chitinase solution is added, adsorption is performed after standing, centrifugal washing is performed, and a fourth compound is obtained; S23. The fourth compound is ultrasonic dispersed in an ammonium molybdate solution, vacuum impregnation is performed, freeze solidification is performed, a dopamine-Tris solution is added, oscillation reaction is performed, centrifugal washing is performed, and vacuum drying is performed to obtain a fifth compound; S24. The fifth compound is dispersed in an ethanol solution of aminopropyltriethoxysilane, reflux reaction is performed, centrifugal washing is performed, and vacuum drying is performed to obtain modified iron-manganese oxide nanocolloid.

4. A cultivation method of a cultivation substrate for enhancing stress resistance of strawberry, applied to the preparation of the cultivation substrate for enhancing stress resistance of strawberry according to any one of claims 1 to 3, characterized in that, The method comprises the following steps: S1. Preparation of raw materials: dissolve the chitosan quaternary ammonium salt in deionized water to prepare a 2% chitosan quaternary ammonium salt solution, mix the modified silicon dioxide and modified iron-manganese oxide nanocolloid in Tris buffer, shake and react, centrifuge and purify, centrifuge and wash with deionized water, vacuum dry to obtain a first mixture; S2. Main matrix mixture: place the main material and calcium sulfate dihydrate in a blender, spray the chitosan quaternary ammonium salt solution while stirring, mix until uniform, and adsorb by standing to obtain a second mixture; S3. Preparation of the cultivation matrix: uniformly spray deionized water into the second mixture, adjust the water content, cover with a breathable film for curing to obtain the cultivation matrix; S4. Layered laying: place the cultivation matrix in a matrix tank, uniformly sprinkle the first mixture on top, and lay the drip irrigation pipe.

5. Application of the cultivation method of the cultivation matrix of any one of claims 1-3 or the cultivation matrix for enhancing the stress resistance of strawberries of claim 4 in improving the yield and quality of strawberries.

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