Application of a silver-silicon nanocomposite material in promoting cucumber seed germination and growth under drought stress

Abstract

The present invention belongs to the field of crop planting technology and specifically relates to the use of a silver-silicon nanocomposite material to promote cucumber seed germination and growth under drought stress. The synthesized Ag@SiO2 NPs of the present invention have the advantages of simple process, low cost, high yield, and good material dispersibility. They can significantly promote cucumber seed germination and growth under drought stress, are simple to operate, have significant effects, are low cost, and are easily disseminated.

Description

Technical Field

[0001] The invention belongs to the technical field of crop planting, and particularly relates to an application of a silver-silicon nanocomposite material in promoting cucumber seed germination and growth under drought stress. Background Art

[0002] Cucumbers are annual vines belonging to the Cucurbitaceae family. Cucumber fruits are crisp, easy to eat, and rich in water. Cucumbers are also rich in various vitamins and minerals, including protein, vitamins, carbohydrates, fiber, fat, and the minerals potassium, phosphorus, magnesium, sodium, iron, and calcium. They also contain health-promoting ingredients such as malonic acid, cucumber enzymes, and cucurbitacin, making them beneficial to human health. Cucumbers are one of the top ten vegetables worldwide and one of China's seven major vegetables, enjoying significant economic value. China leads the world in both cucumber cultivation area and total production. According to FAO (Food and Agriculture Organization of the United Nations), in 2020, the global cucumber production area reached 2.25 million hectares, of which China accounted for 1.27 million hectares, representing 56.4% of the global total. Global cucumber production was 90.35 million tons, of which China produced 73.36 million tons, representing 81.2% of the global total.

[0003] Cucumbers prefer warmth and are intolerant to cold, humidity, drought, and strong sunlight. They require deep, fertile soil rich in organic matter, good aeration, and slightly acidic to neutral soil. Cucumbers are primarily cultivated in open-air, greenhouse, and solar greenhouse environments. Cucumbers are water-intensive vegetables with poor drought resistance. Generally speaking, cucumber-growing areas have good water resources, but this does not necessarily mean that cucumbers receive a timely and adequate supply of water throughout their growth period. Because cucumbers have shallow root systems, weak regeneration capabilities, lush aboveground branches and leaves, and continuous fruiting, they require a large amount of water and are prone to water shortages. Drought stress caused by water shortages can lead to unbalanced physiological functions in cucumber plants, reduced stomatal aperture, and suppressed transpiration and photosynthesis. This results in slow growth, short plants, poor fruit development, high rates of cucumber deformities, small individual cucumber weight, and low yields.

[0004] Drought is an important limiting factor affecting plant seed germination and plant growth, seriously affecting crop yields and planting areas. my country is one of the countries with relatively severe drought in the world. Arid and semi-arid cultivated land accounts for more than 40% of the country's cultivated land area. In 2021, the national drought disaster caused 3426,200 hectares of crops to be affected, with direct economic losses of about 20.09 billion yuan. As the global climate becomes increasingly severe, strengthening research on crop resistance to drought stress is an important guarantee for my country's food security and crop economy. Seed germination is the first step in crop growth, but under drought stress, seeds will not germinate because they absorb too little water. Therefore, developing technologies that enable cucumber seeds to germinate and grow quickly under drought stress is the basis and key to ensuring cucumber yield, planting area and economic value.

[0005] Nanomaterials are solid materials composed of extremely fine crystals with characteristic dimensions on the nanometer scale (0.1 to 100 nm). Due to their unique physicochemical properties, such as small size effects, surface and interface effects, quantum size effects, and quantum tunneling effects, nanomaterials have attracted attention in various fields. Nanopriming is an emerging seed priming technology that uses nanoparticles as seed pretreatment agents and employs seed priming strategies to promote germination, growth, and stress resistance in crop seeds. Research has found that priming rice seeds with nanosilver oxide can effectively improve seed germination rate, average germination time, seed germination index, seed vigor index, and seedling fresh and dry weight. Other studies have reported that nanosilica can improve water use efficiency and water content, and maintain cell expansion, thereby alleviating drought stress in corn and wheat seeds and improving germination rate, root length, and shoot length.

[0006] The present invention uses Ag@SiO2NPs, a nanocomposite material of silver and silicon dioxide, to improve the resistance of cucumber seed germination under drought stress. It is a completely innovative method and also provides a scientific basis and technical support for the application of nanomaterials in arid agriculture. Summary of the Invention

[0007] Based on the above problems, the present invention aims to provide a silver-silicon nanocomposite material for promoting cucumber seed germination and growth under drought stress. The nanocomposite material can significantly increase the yield and survival rate of cucumbers.

[0008] To achieve the above objectives, the present invention provides the following technical solutions.

[0009] One aspect of the present invention provides an application of a silver-silicon nanocomposite material in promoting cucumber seed germination and growth under drought stress.

[0010] Preferably, the silver-silicon nanocomposite material is prepared by a sol-gel method and has a spherical or quasi-spherical shape. The application specifically comprises the following steps:

[0011] S1: Clean and disinfect cucumber seeds;

[0012] S2: Cucumber seeds were soaked in silver-silicon nanocomposite solution;

[0013] S3: The soaked cucumber seeds were subjected to a germination test under drought stress using the Petri dish method.

[0014] Preferably, the silver-silicon nanocomposite material is prepared according to the following steps:

[0015] (1) Dissolve starch in water, adjust the pH to 11 with sodium hydroxide, and add silver nitrate solution during heating and stirring to obtain a nanosilver solution;

[0016] (2) Ethanol and water are added dropwise to the tetraethyl orthosilicate aqueous solution and mixed evenly. The resulting solution is then added dropwise to the above-mentioned nanosilver solution while stirring continuously. Finally, ammonia water is added to form a precipitate, which is filtered. The reaction product is washed, dried, and ground into powder to obtain silver-silicon nanocomposite material Ag@SiO2NPs.

[0017] Preferably, the material-liquid ratio of starch to water added in step (1) is 0.5 g:100 mL.

[0018] Preferably, the heating and stirring temperature in step (1) is 70° C., and the concentration of the silver nitrate solution is 2% w / v.

[0019] Preferably, the volume ratio of ethanol, water and tetraethyl orthosilicate added in step (2) is 400:85:200.

[0020] Preferably, the drying conditions in step (2) are: temperature 40°C, time 24-48h.

[0021] Preferably, in step S2, the material-liquid ratio of the cucumber seeds to the silver-silicon nanocomposite solution is 1 g: 5-10 mL.

[0022] Preferably, the concentration of the silver-silicon nanocomposite material solution in step S2 is 40-80 mg / L.

[0023] Preferably, the drought stress condition in step S3 is: 0-7.5% polyethylene glycol.

[0024] Compared with the prior art, the present invention has the following beneficial effects:

[0025] The synthesized Ag@SiO2NPs of the invention have the advantages of simple process, low cost, high yield and good material dispersibility. They can significantly promote the germination and growth of cucumber seeds under drought stress. The operation is simple, the effect is obvious, the cost is low, and it is easy to promote. According to the test results in the examples of the present invention, when only 0.4 mg of Ag@SiO2NPs is used to treat 1 g of cucumber seeds under drought stress, the germination rate, root length, shoot length, germination index and vitality index of cucumber seeds under drought stress can be significantly promoted, and the germination rate of cucumbers can be accelerated. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 is a scanning electron microscopy (SEM) image of Ag@SiO2NPs prepared according to Example 1;

[0027] Figure 2 shows the effect of 40 mg / L Ag@SiO2NPs in Example 1 on promoting germination and growth of cucumber seeds under drought stress, where (a) is the germination rate; (b) is the sprout length; (c) is the root length; (d) is the germination index; (e) is the vitality index; and (f) is the germination rate.

[0028] Figure 3 shows the effect of 80 mg / L Ag@SiO2NPs in Example 1 on promoting germination and growth of cucumber seeds under drought stress, where (a) is the germination rate; (b) is the sprout length; (c) is the root length; (d) is the germination index; (e) is the vitality index; and (f) is the germination rate.

[0029] Figure 4 This is the result of 80 mg / L Ag@SiO2NPs promoting cucumber seed germination under drought stress in Example 1. Implementation Method

[0030] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described 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 making creative efforts are within the scope of protection of the present invention. Example

[0031] 1. Materials and Methods

[0032] 1.1 Preparation of silver-silicon nanocomposites (Ag@SiO2NPs)

[0033] Dissolve 0.5g of starch in 100mL of deionized water, then add 0.25g of sodium hydroxide to a pH of 11. Stir the starch solution continuously until it reaches 70°C, then add 2% w / v silver nitrate solution to produce a silver nanoparticle solution. Mix 400mL of ethanol and 85mL of water and add dropwise to 200mL of tetraethyl orthosilicate (TEOS). Add the resulting solution dropwise to the silver nanoparticle solution while stirring continuously, and then add ammonia to form a precipitate. Finally, rinse the precipitate five times with deionized water, dry it at 40°C for 24h, and grind it into powder in a quartz mortar to produce the silver-silicon nanocomposite Ag@SiO2NPs.

[0034] 1.2 Preparation of seed soaking solution

[0035] A certain amount of the synthesized Ag@SiO2NPs was weighed using an analytical balance and dissolved in deionized water. Ultrasonic dispersion was performed for 20 minutes to prepare suspensions of 40 and 80 mg / L, respectively, which were the seed soaking solutions.

[0036] 1.3 Test seeds and materials

[0037] Cucumber seeds, the variety is pressed frame fruit cucumber, the seed category is conventional field seeds.

[0038] Preparation of polyethylene glycol solution: PEG = 0%, 0 g / 100 mL; PEG = 7.5%, 7.5 g / 100 mL.

[0039] 1.4 Seed pretreatment

[0040] First, select cucumber seeds of uniform size, full shape, and without empty shells. Place them in a sterilized beaker and disinfect with 5% sodium hypochlorite for 10 minutes. After disinfection, rinse five times with deionized water. After wiping dry with sterile paper, take 1g of cucumber seeds and 5mL of nanomaterials and place them in a 50mL centrifuge tube. Use deionized water as a control. Place in a shaking incubator at 25°C. After 4 hours, remove and wipe dry with sterile paper for excess moisture. Set aside.

[0041] 1.5 Seed germination test

[0042] After treatment, cucumber seeds were evenly distributed in Petri dishes (90 mm diameter) lined with filter paper, with 20 seeds placed in each dish. 3 mL of polyethylene glycol solution of varying concentrations was then added, and the dishes were incubated at 25°C in an intelligent artificial climate chamber, protected from light. The dishes were weighed daily and replenished with the same polyethylene glycol solution to maintain a constant total mass. The number of seeds that germinated was counted daily. After eight days of germination, the length of the shoots and roots was measured. The experiment was replicated four times.

[0043] 1.5 Index determination

[0044] Germination number: The germination is successful if the bud length of the seed exceeds half of the seed;

[0045] Length of sprout: the length of sprout of normally germinated seeds on the eighth day;

[0046] Root length: root length of normally germinated seeds on the eighth day;

[0047] Germination rate (%) = number of germinated seeds on the eighth day / number of test seeds × 100%;

[0048] Germination rate = daily germination rate

[0049] Germination index =

[0050] Vitality index = seed length (root length + sprout length) × germination index

[0051] 2. Experimental Results

[0052] 2.1 Characterization of Ag@SiO2NPs

[0053] Figure 1 Shown is the scanning electron microscopy image of Ag@SiO2NPs. Figure 1 The Ag@SiO2NPs are roughly spherical in shape and relatively uniform in size, ranging from 375 to 445 nm. Dynamic light scattering (DLS) analysis of the hydrated Ag@SiO2NPs (80 mg / L) revealed a particle size of 2242.8 ± 368 nm and a zeta potential of -43.07 ± 0.41 mV.

[0054] 2.2 Effect of 40 mg / L Ag@SiO2 NPs on cucumber seed germination

[0055] After conducting germination experiments according to the above method, the statistical experimental results are shown in Figure 2 below. Eight days after the cucumber seed germination experiment, under a PEG = 0% environment, the experimental group treated with 40 mg / L Ag@SiO2NPs had a higher germination rate (90%) than the control group (81.6%), increased shoot length, root length, germination index, and vigor index, and accelerated germination rate. Under a PEG = 7.5% environment, the experimental group treated with 40 mg / L Ag@SiO2NPs had a higher germination rate (75.0%) than the control group (58.0%), increased shoot and root length, increased germination index by 33% and vigor index by 54%, and accelerated germination rate. This indicates that under drought stress conditions of PEG = 0% and 7.5%, 40 mg / L Ag@SiO2NPs significantly promoted cucumber seed germination and growth.

[0056] 2.3 Effect of 80 mg / L Ag@SiO2 NPs on cucumber seed germination

[0057] After conducting germination experiments according to the above method, the statistical experimental results are shown in Figure 3 below. Eight days after the cucumber seed germination experiment, under a PEG = 0% environment, the experimental group treated with 80 mg / L Ag@SiO2NPs achieved a higher germination rate (93.3%) than the control group (81.6%), increased shoot and root length, germination index, and vigor index, and accelerated germination rate. Under a PEG = 7.5% environment, the experimental group treated with 80 mg / L Ag@SiO2NPs achieved a higher germination rate (83.3%) than the control group (58.0%), increased shoot and root length, increased germination index by 45.3% and vigor index by 73.9%, and accelerated germination rate. This indicates that under drought stress conditions of PEG = 0% and 7.5%, 80 mg / L Ag@SiO2NPs significantly promoted cucumber seed germination and growth.

[0058] The experimental results show that 80 mg / L of Ag@SiO2NPs as a seed treatment significantly increased germination rate, germination index, and vigor compared to 40 mg / L. Therefore, 80 mg / L of Ag@SiO2NPs was selected as the optimal experimental concentration. Ag@SiO2NPs treatment significantly promoted cucumber seed germination, providing an effective solution for cucumber seed sowing and growth in arid or drought-prone areas.

[0059] Anything not described in detail in the present invention is well known to those skilled in the art.

[0060] Finally, it should be noted that the above specific implementation methods are only used to illustrate the technical solutions of the present invention and are not limiting. Although the present invention has been described in detail with reference to the embodiments, those skilled in the art should understand that the technical solutions of the present invention can be modified and replaced with equivalents without departing from the spirit and scope of the technical solutions of the present invention, which should all be included in the scope of the claims of the present invention.

Claims

1. Application of a silver-silicon nanocomposite material in promoting cucumber seed germination and growth under drought stress; The silver-silicon nanocomposite material is prepared according to the following steps: (1) Dissolve starch in water, adjust the pH to 11 with sodium hydroxide, and add silver nitrate solution during heating and stirring to obtain a nanosilver solution; (2) Ethanol and water are added dropwise to the tetraethyl orthosilicate aqueous solution and mixed evenly. The resulting solution is then added dropwise to the above-mentioned nanosilver solution while stirring continuously. Finally, ammonia water is added to form a precipitate, which is filtered. The reaction product is washed, dried, and ground into powder to obtain silver-silicon nanocomposite material Ag@SiO2NPs.

2. The use according to claim 1, characterized in that The silver-silicon nanocomposite material is prepared by a sol-gel method and has a spherical or quasi-spherical shape. The application specifically includes the following steps: S1: Clean and disinfect cucumber seeds; S2: Cucumber seeds were soaked in silver-silicon nanocomposite solution; S3: The soaked cucumber seeds were subjected to a germination test under drought stress using the Petri dish method.

3. The use according to claim 1, characterized in that The material-liquid ratio of starch to water added in step (1) is 0.5 g:100 mL.

4. The use according to claim 1, characterized in that The heating and stirring temperature in step (1) is 70° C., and the concentration of the silver nitrate solution is 2% w / v.

5. The use according to claim 1, characterized in that The volume ratio of ethanol, water and tetraethyl orthosilicate added in step (2) is 400:85:

200.

6. The use according to claim 1, characterized in that The drying conditions in step (2) are: temperature 40°C, time 24-48h.

7. The use according to claim 2, characterized in that The material-liquid ratio of the cucumber seeds to the silver-silicon nanocomposite solution in step S2 is 1 g: 5-10 mL.

8. The use according to claim 2, characterized in that The concentration of the silver-silicon nanocomposite material solution in step S2 is 40-80 mg / L.

9. The use according to claim 2, characterized in that The drought stress condition in step S3 is: 0-7.5% polyethylene glycol.

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