Plant growth regulator with shellac loaded with oligosaccharide as well as preparation and application of plant growth regulator

Abstract

The invention provides a shellac-based oligosaccharide plant growth regulator which can delay the degradation rate of oligosaccharide and slowly release the oligosaccharide. The delivery system is composed of shellac and oligosaccharide, the shellac serves as a carrier, and the oligosaccharide serves as a loading substance. The shellac can be subjected to chemical group modification so as to improve the biocompatibility and targeting property of the shellac. Groups such as oligosaccharide hydroxyl and amino are combined with hydroxyl of shellac through hydrogen bonds and the like to form a stable oligosaccharide-shellac compound, so that the activity stability of oligosaccharide can be improved, a slow-release effect is provided, plant growth is promoted, and the yield and quality are improved.

Description

Technical Field

[0001] The present invention relates to the technical field of oligosaccharide delivery, and in particular to an oligosaccharide preparation delivered by shellac and having a sustained-release effect, a preparation method and application thereof in promoting plant growth and the like. Background Art

[0002] Plant growth regulators play an important role in agricultural production. They can promote growth, increase yield and improve quality by regulating the physiological and biochemical processes of plants. Oligosaccharides are a class of naturally occurring oligosaccharides, which are composed of 2-10 monosaccharide molecules connected by glycosidic bonds. Studies have shown that oligosaccharides play an important role in plant growth and development, including regulating cell division and expansion, promoting nutrient absorption, and improving resistance to pests and diseases. Although studies have attempted to use oligosaccharides for plant growth regulation, the existing technology still faces some challenges, mainly including the lack of stability of oligosaccharides in the environment and poor durability caused by easy degradation. These deficiencies make it difficult for the growth regulation effect of oligosaccharides to be stable and lasting. Therefore, it is necessary to further optimize the encapsulation technology and controlled release mechanism to enhance the application effect of oligosaccharides in plant growth regulation. Current research uses microencapsulation technology, nanocarriers and responsive carriers to encapsulate oligosaccharides to improve their stability and optimize their biological activity and efficacy. However, the preparation process is complicated and difficult to scale up production.

[0003] Shellac is a natural resin with excellent biocompatibility, film-forming and sustained-release properties, and is widely used in food, medicine, cosmetics and other fields. Therefore, using shellac as a carrier material can effectively protect oligosaccharides, slow down the degradation of oligosaccharides, and release them slowly and continuously, thus solving the problem of easy degradation of oligosaccharides in applications. Summary of the invention

[0004] The present invention provides a delivery system of oligosaccharides loaded with shellac. The loading of shellac improves the stability of oligosaccharides and enables the oligosaccharides to be slowly released, thereby continuously exerting their effect of promoting plant growth. The invention overcomes the problems of easy degradation of oligosaccharides and short-lasting effects, and provides a natural, safe and efficient plant growth regulator.

[0005] The technical solution of the present invention includes:

[0006] 1. Composition of the delivery system:

[0007] The delivery comprises shellac, oligosaccharides and auxiliary materials, wherein the shellac is purchased from Shanghai MacLean Biochemical Technology Co., Ltd. The weight ratio of shellac to oligosaccharides is 1:0.1-1:10. The auxiliary materials are selected from adhesives, thickeners, fillers or preservatives, wherein:

[0008] The binder and thickener are selected from one or more of gum arabic, guar gum, xanthan gum, sodium polyacrylate and sodium carboxymethyl cellulose;

[0009] The filler is selected from an inorganic filler or an organic filler, the inorganic filler is selected from one or more of talc, diatomaceous earth and calcium powder, and the organic filler is selected from one or more of cellulose, starch and lactose;

[0010] The preservative is selected from one or more of sodium benzoate, potassium sorbate and parabens.

[0011] The oligosaccharide is chitosan oligosaccharide, sodium alginate oligosaccharide or other natural oligosaccharides that can activate plant cell growth or induce plants to produce systemic resistance.

[0012] Natural shellac or ethanol esterified modified shellac, wherein the ethanol esterified modified shellac is prepared by dissolving shellac in a proper amount of ethanol, adding sulfuric acid as a catalyst into the system, and heating and stirring at 70° C. for 6 hours.

[0013] 2. Preparation of sustained-release delivery system:

[0014] Dissolve 5-20 g of shellac in 100-200 mL of 0.5%-2% ammonia solution to obtain a shellac solution;

[0015] Add 0.5-50 g of oligosaccharide to the shellac solution and stir at room temperature for 0.5-2 h until the oligosaccharide is completely dissolved and evenly dispersed to obtain an oligosaccharide-shellac complex solution;

[0016] spray drying the obtained oligosaccharide-shellac complex to obtain a powdered or granular oligosaccharide-shellac complex;

[0017] 3. Application method:

[0018] The dried oligosaccharide-shellac complex powder or granules are dissolved in an appropriate amount of water to prepare a solution with a concentration of 0.01 g / L-5 g / L.

[0019] Choose the appropriate application method and spray the prepared solution evenly on the leaves, stems or roots of the plants. Make sure that each treatment can fully cover the plant surface so that the oligosaccharide-shellac complex can be effectively absorbed and utilized by the plants.

[0020] The steps of spraying or soaking the plants include: spraying the prepared solution evenly on the leaves, stems or roots of the plants, and the spraying amount should be sufficient to cover the surface of the plants; or soaking the roots of the plants in the prepared solution for a time sufficient for the roots to fully absorb the solution.

[0021] Applied plants include food crops, cash crops, vegetable crops, fruit trees or flower plants, etc.

[0022] The spraying or dipping step is carried out at a critical stage of plant growth, such as germination, flowering or fruiting.

[0023] The product application method can be adjusted according to crop type and growth stage to optimize the growth regulation effect.

[0024] The delivery system consists of shellac and oligosaccharides, wherein shellac is used as a carrier and oligosaccharides are used as a loading substance. The surface of shellac can be modified with chemical groups to improve its biocompatibility and targeting. The loading of shellac can slow down the degradation of oligosaccharides, provide a slow-release effect, promote plant growth, and improve yield and quality.

[0025] 4.Technical advantages:

[0026] Improving the stability of oligosaccharides: The sustained-release delivery system of oligosaccharides loaded with shellac can effectively improve the defects of oligosaccharides such as insufficient stability and easy degradation in the environment, improve the stability of oligosaccharides, slow down the rate of oligosaccharide degradation, and provide a new, green and long-lasting biological plant growth regulator for agricultural production.

[0027] Slow-release effect: Using shellac as a carrier can effectively slow down the release rate of oligosaccharides. Oligosaccharides are gradually released from the complex, maintaining the persistence of their plant growth regulating activity.

[0028] Growth promotion: As a biologically active substance, oligosaccharides can promote plant root growth and nutrient absorption, improve plant photosynthesis efficiency and stress resistance, and thus significantly promote plant growth and development.

[0029] Safety and environmental protection: The present invention adopts natural shellac and natural oligosaccharides as main ingredients, which are non-toxic, harmless, and environmentally friendly, and will not cause pollution and damage to crops and soil.

[0030] Easy application: The preparation method is simple, suitable for large-scale production and agricultural application, and can be widely used in the growth regulation of various crops, including food crops, cash crops, vegetables, fruit trees and flowers.

[0031] 5. Application scope:

[0032] The shellac-loaded oligosaccharide delivery system of the present invention is suitable for agricultural production systems under different climate and soil conditions, and provides an effective means and new choice for increasing crop yield, improving fruit quality, and optimizing agricultural resource utilization efficiency.

[0033] The invention can be widely used in the growth regulation of various plants such as food crops, cash crops, vegetable crops, fruit trees and flowers, and is helpful to improve agricultural production efficiency and crop quality. DETAILED DESCRIPTION

[0034] The shellac-loaded oligosaccharide preparation of the present invention is composed of shellac and oligosaccharides. The technical scheme in the embodiments of the present invention is clearly and completely described below in conjunction with specific embodiments. Obviously, the embodiments described below are only embodiments of some commonly used proportions of the present invention, rather than all embodiments. The content of the present invention is not limited to the following embodiments. Based on the following embodiments, all other embodiments obtained by ordinary technicians in this field without creative work belong to the protection scope of the present invention.

[0035] Embodiment 1:

[0036] Dissolve 8 g of shellac in 100 mL of 1 wt% ammonia solution, heat to 60°C to dissolve, and stir evenly.

[0037] Add 1.5g of sodium alginate oligosaccharide with an average molecular weight of 1000Da to the shellac solution, gradually add and continue stirring for 1h until the oligosaccharide is completely dissolved and fully mixed with the shellac. In this process, add the following excipients to the final concentration: 0.5wt% xanthan gum and 0.2wt% sodium carboxymethyl cellulose as adhesives and thickeners; 1wt% talcum powder as a filler; 0.1wt% sodium benzoate as a preservative. After the ingredients are evenly mixed in proportion, continue stirring to ensure complete uniformity. The oligosaccharide-shellac complex solution is treated by spray drying (the spray drying inlet temperature is 140°C and the outlet temperature is 80°C) to obtain the product (oligosaccharide-shellac complex).

[0038] In order to simulate the degradation of sodium alginate oligosaccharide in the complex, 0.5g oligosaccharide-shellac complex was wrapped with 100 mesh gauze and buried in a soil column with a diameter of 5cm. The soil mass in the soil column was 150g, the soil column height was 6cm, and the wrapping burial depth was 3cm. The soil moisture content was kept at 50%. After 20 days, 500ml deionized water was used to leach the soil column. The content of sodium alginate oligosaccharide in the soil was calculated by the leaching solution. After that, the gauze was taken out, and the remaining mixture in the gauze was dispersed in 50mL water. The pH of the dispersion was adjusted to 8 with 1M sodium hydroxide. After centrifugation, the amount of sodium alginate oligosaccharide in the supernatant was tested at 230nm using a UV-visible spectrophotometer to obtain the amount of sodium alginate oligosaccharide in the remaining complex in the gauze. The degradation amount of sodium alginate oligosaccharide was obtained by subtracting the amount of sodium alginate oligosaccharide in the leaching solution from the amount of sodium alginate oligosaccharide in the raw material and the amount of sodium alginate oligosaccharide in the remaining complex in the gauze. At the same time, the same experiment was carried out with 0.5 g of sodium alginate oligosaccharide instead of the above oligosaccharide-shellac complex (the process and conditions were the same as above). The results showed that sodium alginate oligosaccharide was degraded by 35% after 20 days, while the sodium alginate oligosaccharide in the oligosaccharide-shellac complex was only degraded by 12% in 20 days, showing the performance of the oligosaccharide-shellac complex in alleviating the degradation of oligosaccharides in soil.

[0039] The calculation method of sodium alginate concentration is as follows: sodium alginate oligosaccharide solutions with mass concentrations of 0.01wt%, 0.02wt%, 0.03wt%, 0.04wt%, and 0.05wt% are respectively tested in a UV-visible spectrophotometer at 230nm to obtain the absorbance / concentration standard curve of sodium alginate oligosaccharide:

[0040] y=37.282x+0.079, R2=0.9963

[0041] Embodiment 2:

[0042] Dissolve 5 g of shellac in 100 mL of 1 wt% ammonia solution, heat to 60°C, and stir evenly.

[0043] Add 1g of chitosan oligosaccharide with an average molecular weight of 1500Da to the shellac solution, gradually add and continue stirring until the oligosaccharide is completely dissolved and fully mixed with the shellac. During this process, add the following final concentration excipients: 0.5wt% xanthan gum as a thickener, 0.5wt% sodium polyacrylate as a binder, 1wt% talc as a filler, and 0.1wt% sodium benzoate as a preservative. After all ingredients are evenly mixed in proportion, continue stirring to ensure that a stable complex solution is formed.

[0044] A glass dish was used to simulate plant leaves, and 10 mL of oligosaccharide-shellac complex solution was sprayed on the bottom surface of the glass dish. The mouth of the glass dish was sealed to prevent water evaporation, and the glass dish was placed in a constant temperature incubator with an incubator temperature of 25 ° C and a humidity of 60%. At the same time, the same experiment was carried out with chitosan oligosaccharides of equal mass instead of the above-mentioned oligosaccharide-shellac complex (the process and conditions were the same as above). After 20 days, the substances on the surface of the glass dish were collected to test the degradation rate of chitosan oligosaccharides. The results showed that chitosan oligosaccharides degraded by 25.4% in 20 days, while the chitosan oligosaccharides in the oligosaccharide-shellac complex only degraded by 8%. The results show that the oligosaccharide-shellac complex can effectively alleviate the degradation of oligosaccharides after spraying plant leaves.

[0045] Embodiment 3:

[0046] Dissolve 10 g of shellac in 100 mL of 1 wt% ammonia solution and stir well.

[0047] Add 2.5g of sodium alginate oligosaccharide with an average molecular weight of 1000Da to the shellac solution, gradually add and continue stirring until the oligosaccharide is completely dissolved and fully mixed with the shellac. During this process, add the following final concentration excipients: 0.7wt% xanthan gum as a thickener, 0.5wt% gum arabic as an adhesive, 1.2wt% talcum powder as a filler, and 0.15wt% potassium sorbate as a preservative. All ingredients are evenly mixed in proportion and continued to stir to ensure that a stable complex solution is obtained. The oligosaccharide-shellac complex solution is spray dried, and the inlet temperature is controlled at 100-120°C and the outlet temperature is 80°C, so that the solution is quickly dried into a powdered composition.

[0048] The release rate of sodium alginate oligosaccharides was tested by simulating soil column experiments. 0.5g of oligosaccharide-shellac complex was wrapped with 100 mesh gauze and buried in a soil column with a diameter of 5cm. The soil mass in the soil column was 150g, the soil column height was 6cm, and the wrapped burial depth was 3cm. 100ml of deionized water was used to leach the soil column every 3 days, and the cumulative release of sodium alginate oligosaccharides was calculated by testing the absorbance of the leaching liquid at 230nm using a UV-visible spectrophotometer (the calculation method was the cumulative release of sodium alginate oligosaccharides mass / the mass of sodium alginate oligosaccharides contained in the complex). At the same time, the control group replaced the oligosaccharide-shellac complex with the same amount of sodium alginate oligosaccharides for the same experiment (the process and conditions were the same as above). The results showed that after 30 days, only 32.5% of the sodium alginate oligosaccharides in the oligosaccharide-shellac complex were released, while the sodium alginate oligosaccharides in the control group were released about 85.4%. The results show the slow-release performance of oligosaccharides in oligosaccharide-shellac complexes.

[0049] Embodiment 4:

[0050] 20 g of shellac was added to 200 mL of 1 wt% ammonia water, and the mixture was heated and stirred continuously until the shellac was completely dissolved to form a shellac solution.

[0051] 20 g of chitosan oligosaccharide with an average molecular weight of 1500 Da was added, and the mixture was stirred and mixed thoroughly to ensure that the oligosaccharide was evenly dispersed in the shellac solution to form an oligosaccharide-shellac complex solution. During this process, the following excipients were added at a final concentration: 1 wt% guar gum as a thickener, 0.5 wt% sodium carboxymethyl cellulose as a binder, 0.8 wt% diatomaceous earth as a filler, and 0.2 wt% methyl paraben as a preservative.

[0052] The oligosaccharide-shellac complex solution was spray-dried (the spray drying inlet temperature was 140° C. and the outlet temperature was 80° C.) to obtain the oligosaccharide-shellac complex.

[0053] Solution preparation and spraying application:

[0054] The dried powder was prepared into a 0.1 g / L dispersion (water as the dispersion liquid).

[0055] 30L per acre of the dispersed system was sprayed on 5 acres of wheat fields in the seedling stage, and the wheat growth was monitored and recorded. At the same time, it was compared with 5 acres of wheat fields sprayed with the same amount and concentration of chitosan oligosaccharides.

[0056] The growth of wheat and the yield at harvest time were observed, and the promoting effect of oligosaccharide-shellac complex on wheat growth was analyzed.

[0057] The application of sustained-release preparations loaded with oligosaccharides by shellac significantly promoted the growth of wheat. Compared with the wheat fields sprayed with the same amount of chitosan oligosaccharides, 20 wheat seedlings at different tillering stages were taken for comparison. The leaves of the oligosaccharide-shellac complex treatment group were darker green, with an average plant height of 37.4 cm and an average number of tillers of 8; while the average plant height of the control group during the tillering period was 30.6 cm and the average number of tillers was 6. After the wheat matured, the per-acre yield of wheat was calculated. The per-acre yield of wheat in the oligosaccharide-shellac treatment group was 430 kg, and the average thousand-grain weight was 47.6 g. The per-acre yield of wheat in the control group was 350 kg, and the average thousand-grain weight was 43.7 g. . This shows that the oligosaccharide-shellac complex can effectively improve the growth quality of wheat.

[0058] Embodiment 5:

[0059] 12 g of shellac was dissolved in 120 mL of 2 wt% ammonia solution and stirred until the shellac was completely dissolved to form a shellac solution.

[0060] Add 10g of pectin oligosaccharide with an average molecular weight of 1500Da to the shellac solution, and stir gently until the oligosaccharide is fully dissolved and evenly dispersed to obtain an oligosaccharide-shellac complex solution. In this process, add the following final concentration excipients: 0.5wt% xanthan gum and 0.2wt% sodium carboxymethyl cellulose as a binder and thickener; 1wt% talcum powder as a filler; 0.1wt% sodium benzoate as a preservative. After the ingredients are evenly mixed in proportion, continue stirring to ensure complete uniformity.

[0061] The oligosaccharide-shellac complex solution was spray-dried (the spray drying inlet temperature was 140° C. and the outlet temperature was 80° C.) to obtain a granular complex.

[0062] 0.5 g of the dried composite particles were dispersed in 500 mL of water and stirred evenly to prepare an oligosaccharide-shellac dispersion system.

[0063] The dispersed system was used to soak the roots of tomato seedlings at the seedling stage when the first true leaf appeared for 24 hours. The growth of the tomato seedlings was observed by comparing with that of the tomato seedlings that were not soaked or soaked with the same amount of pectin oligosaccharide (0.5g pectin oligosaccharide dissolved in 500mL water).

[0064] To monitor the health status of tomato plants and fruit quality, and to analyze the effects of oligosaccharide-shellac complexes on tomato growth and fruit development.

[0065] Through the oligosaccharide-shellac dispersion soaking treatment experiment of tomato seedling roots, it was observed that tomatoes grew more robustly. The stem thickness of 20 random seedlings was tested 4 weeks after root soaking. The average stem thickness of the seedlings treated with oligosaccharide-shellac was 0.6cm, the average stem thickness of the group using pectin oligosaccharide alone was 0.5cm, and the average stem thickness of the group not soaked in the root was 0.3cm. The fruit quality during the fruiting period was significantly improved. The average single fruit weight of tomatoes treated with oligosaccharide-shellac complex was 220g, the average single fruit weight of the group soaked in oligosaccharide alone was 190g, and the average single fruit weight of the group not soaked in the root was 180g. The results showed that the soaking treatment of oligosaccharide-shellac dispersion accelerated the growth and development of fruits. The average single plant yield of tomatoes in the oligosaccharide shellac treatment group was 1.35kg. The average single plant yield of tomatoes in the non-root soaking group was 1.04kg, and the average single plant yield of tomatoes in the group soaked in the root with the same amount of oligosaccharide alone was 1.18kg. The potential of the complex in improving the growth quality of tomatoes was verified.

[0066] Embodiment 6:

[0067] 8 g of shellac was dissolved in 200 mL of 1 wt% ammonia solution and stirred to completely dissolve the shellac to form a shellac solution.

[0068] Add 3g of sodium alginate oligosaccharide with an average molecular weight of 1000Da to the shellac solution, stir and mix thoroughly to ensure that the oligosaccharide is evenly dispersed in the shellac solution to form an oligosaccharide-shellac complex solution. In this process, add the following final concentration excipients: 1wt% guar gum as a thickener, 0.5wt% sodium carboxymethyl cellulose as a binder, 0.8wt% diatomaceous earth as a filler, and 0.2wt% methyl paraben as a preservative. The oligosaccharide-shellac complex solution is dried by spray drying (the spray drying inlet temperature is 140°C and the outlet temperature is 80°C) to convert the solution into a powdered complex.

[0069] Solution preparation and spraying application:

[0070] The dried composite was prepared into a uniform dispersion system (water as the dispersion liquid) at 0.2 g / L.

[0071] 30L of oligosaccharide-shellac dispersion per acre was sprayed on corn fields at the seedling stage, and the changes in corn growth and yield were evaluated by comparing with corn fields that were not sprayed with the dispersion.

[0072] During the growth of corn, spraying experiments using oligosaccharide-shellac dispersions showed that the complex significantly promoted the growth and development of corn. The average length and stem thickness of the aboveground part of corn plants during the jointing period were statistically analyzed. The results showed that the average length of the aboveground part treated with oligosaccharide-shellac was 78.8 cm, and the average stem thickness was 1.7 cm; the average length of the aboveground part of the control group was 77.8 cm, and the average stem thickness was 1.5 cm. During the tasseling period, the average length and stem thickness of the aboveground part of corn plants were also statistically analyzed. The results showed that the average length of the aboveground part treated with oligosaccharide-shellac was 2.46 m, and the average stem thickness was 2.3 cm; the average length of the aboveground part of the control group was 1.94 m, and the average stem thickness was 2.0 cm. Spraying treatment effectively improved the yield and quality of corn. The average yield of corn treated with oligosaccharide-shellac was 445 kg per mu, while the average yield of corn in the control group was 390 kg per mu.

[0073] Embodiment 7:

[0074] Dissolve 8 g of shellac in 80 mL of 1 wt% ammonia solution, heat to 60°C, and stir evenly.

[0075] 1.5 g of sodium alginate oligosaccharide with an average molecular weight of 1000 Da was added to the shellac solution, and the oligosaccharide was gradually added and stirred continuously until the oligosaccharide was completely dissolved and fully mixed with the shellac. During this process, the following excipients were added at a final concentration: 0.7 wt% of xanthan gum as a thickener, 0.5 wt% of gum arabic as a binder, 1.2 wt% of talc as a filler, and 0.15 wt% of potassium sorbate as a preservative. All ingredients were evenly mixed in proportion and stirring was continued to ensure that a stable composite solution was obtained.

[0076] The oligosaccharide-shellac complex solution is treated by a spray drying device to form a fine particle complex.

[0077] The parameters of the drying equipment were adjusted to a spray drying inlet temperature of 150°C and an outlet temperature of 80°C to ensure uniformity of the composite particles and preservation of the active ingredients during the drying process.

[0078] 0.3 g of the dried composite particles were dispersed in 300 mL of water, the concentration of the dispersion was adjusted and the mixture was stirred thoroughly to obtain a dispersion.

[0079] The dispersed system was used for root soaking treatment of apple seedlings. At the same time, a control group of apple seedlings soaked in the same concentration of sodium alginate oligosaccharides was set up to evaluate the root growth and seedling condition of the apple seedlings.

[0080] Through the oligosaccharide-shellac dispersion soaking treatment experiment on the roots of apple seedlings, it was observed that the root system grew healthier and stronger after one year of planting. The average root neck thickness of apple seedlings treated with oligosaccharide-shellac complex was 1.4cm, and the average root neck thickness of the control group was 1.1cm. The soaking treatment improved the root structure and growth of fruit seedlings. The growth of apple seedlings one year after planting was evaluated. The results showed that the average height of apple seedlings treated with oligosaccharide-shellac complex was 1.86m, the average number of branches was about 4, and the average survival rate of seedlings was 95%; the average height of seedlings in the control group was 1.78m, the average number of branches was 4, and the average survival rate of seedlings was 86%, showing the potential and application effect of the complex in fruit tree growth.

[0081] Embodiment 8:

[0082] The shellac is dissolved in 5 times the amount of ethanol relative to the mass of the shellac, and 98 wt% sulfuric acid at a mass concentration of 0.005 times the mass of the shellac is added into the system as a catalyst. The mixture is heated and stirred at 70°C for 6 hours and then vacuum dried for 5 hours to obtain ethanol-modified esterified shellac. 5 g of the ethanol-modified esterified shellac is selected and its powder is dissolved in 100 mL of 1 wt% ammonia solution, and the shellac is completely dissolved by heating and stirring.

[0083] 2 g of sodium alginate oligosaccharide with an average molecular weight of 1000 Da was added to the shellac solution, and the mixture was gradually added and stirred to ensure that the oligosaccharide was fully dissolved and evenly dispersed in the shellac solution. During this process, the following excipients were added at a final concentration: 1 wt% guar gum as a thickener, 0.5 wt% sodium carboxymethyl cellulose as a binder, 0.8 wt% diatomaceous earth as a filler, and 0.2 wt% methyl paraben as a preservative.

[0084] The oligosaccharide-shellac complex solution is spray-dried to obtain the oligosaccharide-shellac complex.

[0085] The parameters of the drying equipment were adjusted to a spray drying inlet temperature of 140°C and an outlet temperature of 80°C to ensure the stability of the composite powder and the integrity of the active ingredients.

[0086] The dried composite was prepared into a uniform dispersion system of 0.2 g / L.

[0087] 30L of the dispersion per acre was sprayed on vegetables in the seedling stage, and the growth and yield changes of the vegetables were observed and recorded in comparison with the control group that was not sprayed with the oligosaccharide-shellac dispersion.

[0088] In the vegetable planting base, the regular spraying experiment using oligosaccharide-shellac complex dispersion system showed that the vegetables grew healthier and faster. The spraying treatment significantly improved the yield and quality of vegetables. After spraying the oligosaccharide-shellac dispersion system, the average per-acre yield of spinach was 3850kg, the average per-acre yield of eggplant was 7300kg, and the average per-acre yield of potato was 4200kg; the average per-acre yield of spinach in the control group was 3120kg, the average per-acre yield of eggplant was 5850kg, and the average per-acre yield of potato was 3300kg; the wide applicability and growth promotion effect of the complex in the growth of different crops were verified.

[0089] Embodiment 9:

[0090] Dissolve 10 g of shellac in 100 mL of 1 wt% ammonia solution and stir until the shellac is completely dissolved to form a shellac solution.

[0091] 3 g of chitosan oligosaccharide with an average molecular weight of 1500 Da was added to the shellac solution and stirred until the oligosaccharide was fully dissolved and uniformly dispersed to obtain an oligosaccharide-shellac complex solution. During this process, the following excipients were added at a final concentration: 1 wt% of guar gum as a thickener, 0.5 wt% of sodium carboxymethyl cellulose as a binder, 0.8 wt% of diatomaceous earth as a filler, and 0.2 wt% of methyl paraben as a preservative.

[0092] The oligosaccharide-shellac complex solution was spray-dried (the spray drying inlet temperature was 140° C. and the outlet temperature was 80° C.) to obtain a granular oligosaccharide-shellac complex.

[0093] 4 kg of oligosaccharide-shellac composite particles per mu were applied to a moderate saline-alkali test field with a pH of 7.1-8.0 and a salt content of 0.4 wt %, and cucumbers were planted to observe the growth of the cucumber seedlings. The field without application was used as a control group.

[0094] The growth status, plant height and fruit condition of cucumber plants were monitored, and the effects of oligosaccharide-shellac composite particles on the resistance of cucumber to salt-alkali stress and the development of cucumber fruit were analyzed.

[0095] By comparing the growth and fruit development of cucumber plants treated with oligosaccharide-shellac composite particles and those not treated, it was observed that after the application of oligosaccharide-shellac composite particles, the average growth rate of the main vine in the vigorous period was 8 cm / d, and the average stem thickness was 0.9 cm; the average growth rate of the main vine in the control group was 6 cm / d, and the average stem thickness was 0.8 cm. The growth indicators of different treatments during the harvest period were evaluated. The average fruit length of cucumbers treated with oligosaccharide-shellac was 21 cm, the average fruit diameter was 4.5 cm, and the average weight of a single fruit was 210 g; the average fruit length of cucumbers in the control group was 18 cm, the average fruit diameter was 4 cm, and the average weight of a single fruit was 185 g. After the application of composite particles, cucumber seedlings showed obvious resistance to salt-alkali stress, and the quality of cucumber fruits could be improved, showing the ability of oligosaccharide-shellac composites to enhance the resistance of plants to abiotic stress.

[0096] Embodiment 10:

[0097] Dissolve 3 g of shellac in 100 mL of 1 wt% ammonia solution and stir until the shellac is completely dissolved to form a shellac solution.

[0098] 35 g of sodium alginate oligosaccharide with an average molecular weight of 1500 Da was added to the shellac solution and stirred until the oligosaccharide was fully dissolved and uniformly dispersed to obtain an oligosaccharide-shellac complex solution. During this process, the following excipients were added at a final concentration: 1 wt% guar gum as a thickener, 0.5 wt% sodium carboxymethyl cellulose as a binder, 0.8 wt% diatomaceous earth as a filler, and 0.2 wt% methyl paraben as a preservative.

[0099] The oligosaccharide-shellac complex solution was spray-dried (the spray drying inlet temperature was 140° C. and the outlet temperature was 90° C.) to prepare the oligosaccharide-shellac complex.

[0100] The release rate of sodium alginate oligosaccharides was tested by simulating soil column experiments. 0.5g oligosaccharide-shellac complex was wrapped with 100 mesh gauze and buried in a soil column with a diameter of 5cm. The soil mass in the soil column was 150g, the soil column height was 6cm, and the wrapped burial depth was 3cm. 100ml of deionized water was used to leach the soil column every 3 days, and the cumulative release of sodium alginate oligosaccharides was calculated by testing the absorbance of the leaching solution at 230nm using a UV-visible spectrophotometer. The test results showed that after the first leaching, the cumulative release rate of sodium alginate oligosaccharides detected in the leaching solution was 65%; after the second leaching, the cumulative release rate of sodium alginate oligosaccharides was 72%; after the third leaching, the cumulative release rate was 77%. In the subsequent leaching process, sodium alginate oligosaccharides were gradually released slowly, and after the tenth leaching, the cumulative release rate of sodium alginate oligosaccharides was 85%. The above test results show that when the mass ratio of shellac to oligosaccharides is too low (i.e. the oligosaccharide content exceeds the protection scope of the claims), the oligosaccharides may be released suddenly, resulting in the failure of the oligosaccharide-shellac complex to achieve a sustained release effect.

[0101] Embodiment 11:

[0102] Dissolve 5 g of shellac in 100 mL of 1 wt% ammonia solution and stir until the shellac is completely dissolved to form a shellac solution.

[0103] 0.3 g of sodium alginate oligosaccharide with an average molecular weight of 1500 Da was added to the shellac solution and stirred until the oligosaccharide was fully dissolved and uniformly dispersed to obtain an oligosaccharide-shellac complex solution. During this process, the following excipients were added at a final concentration: 1 wt% guar gum as a thickener, 0.5 wt% sodium carboxymethyl cellulose as a binder, 0.8 wt% diatomaceous earth as a filler, and 0.2 wt% methyl paraben as a preservative.

[0104] The oligosaccharide-shellac complex solution was spray-dried (the spray drying inlet temperature was 140° C. and the outlet temperature was 60° C.) to prepare the oligosaccharide-shellac complex.

[0105] The oligosaccharide-shellac complex obtained was dispersed in deionized water to prepare a 20 mg / L dispersion system. 50 mL of the dispersion system was used to treat rice seeds, and the same amount and concentration of sodium alginate oligosaccharide were used as a control. The treated rice seeds were placed in a culture dish and cultured in a constant temperature incubator under the conditions of 28°C and 80% relative humidity. The germination rate of the rice seeds and the bud length 7 days after germination were monitored.

[0106] The test results show that the germination rate of rice seeds treated with oligosaccharide-shellac complex is 74%, and the average bud length is 8 cm after germination for 7 days; the germination rate of rice seeds treated with sodium alginate oligosaccharide is 87%, and the average bud length is 13 cm after germination for 7 days. This result shows that when the mass ratio of shellac to oligosaccharide is too high (that is, the oligosaccharide content is lower than the protection scope of the claim), the oligosaccharide-shellac complex releases a low content of oligosaccharides and cannot provide enough oligosaccharides to promote plant growth.

[0107] Comparative Example 1:

[0108] Polylactic acid loaded with sodium alginate oligosaccharide

[0109] Materials preparation:

[0110] Preparation of polylactic acid loaded sodium alginate oligosaccharide:

[0111] Dissolve polylactic acid in chloroform to prepare 100 mL of a 5% polylactic acid solution. Slowly add 1 g of Da sodium alginate oligosaccharide with an average molecular weight of 1500 to the polylactic acid solution and stir. The oligosaccharide is insoluble in chloroform and precipitates at the bottom of the polylactic acid solution.

[0112] Dissolve 1g of Da sodium alginate oligosaccharide with an average molecular weight of 1500 in 100mL of water, add 5g of polylactic acid to the sodium alginate oligosaccharide solution, and stir. Polylactic acid cannot dissolve in water and precipitates at the bottom of the sodium alginate oligosaccharide solution.

[0113] Dissolve polylactic acid in chloroform to prepare 50 mL of a polylactic acid solution with a mass concentration of 10%. Dissolve 1 g of sodium alginate oligosaccharide with an average molecular weight of 1500 in 50 mL of water to prepare a sodium alginate oligosaccharide solution. Mix the polylactic acid solution with the sodium alginate oligosaccharide solution and stir. After stopping stirring, the polylactic acid solution and the oligosaccharide solution are separated, and a uniform solution of polylactic acid and oligosaccharides cannot be prepared.

[0114] Therefore, directly compounding polylactic acid with oligosaccharides cannot obtain a uniform solution of polylactic acid and oligosaccharides, and it is impossible to achieve polylactic acid embedding oligosaccharides.

[0115] Comparative Example 2:

[0116] Comparison of polyvinyl alcohol and shellac loaded with sodium alginate oligosaccharides

[0117] Preparation of polyvinyl alcohol loaded sodium alginate oligosaccharides:

[0118] Add polyvinyl alcohol powder to deionized water, heat to 80°C and stir until the polyvinyl alcohol is completely dissolved to form 100 mL of polyvinyl alcohol solution with a mass concentration of 5%. Slowly add sodium alginate oligosaccharide to the polyvinyl alcohol solution and continue to stir evenly to ensure that the oligosaccharide is evenly dispersed in the polyvinyl alcohol. A composite solution of polyvinyl alcohol loaded with sodium alginate oligosaccharide is obtained.

[0119] Preparation of shellac-loaded sodium alginate oligosaccharides:

[0120] Dissolve 5g of natural shellac powder in 100mL of 1wt% ammonia solution, heat to 60°C, and stir evenly. Add 1g of sodium alginate oligosaccharide with an average molecular weight of 1500Da to the shellac solution, gradually add and continue stirring until the oligosaccharide is completely dissolved and fully mixed with the shellac. During this process, add the following final concentration excipients: 0.5wt% of xanthan gum as a thickener, 0.5wt% of sodium polyacrylate as an adhesive, 1wt% of talcum powder as a filler, and 0.1wt% of sodium benzoate as a preservative. After all the ingredients are evenly mixed in proportion, continue stirring to ensure that a stable complex solution is formed. The oligosaccharide-shellac complex solution is spray dried (the spray drying inlet temperature is 140°C and the outlet temperature is 80°C) to obtain an oligosaccharide-shellac complex.

[0121] The release rate of sodium alginate oligosaccharides was tested by simulating soil column experiments. 0.5g oligosaccharide-shellac complex and polyvinyl alcohol-loaded sodium alginate oligosaccharide complex were wrapped with 100-mesh gauze and buried in a soil column with a diameter of 5cm. The soil mass in the soil column was 150g, the soil column height was 6cm, and the wrapped burial depth was 3cm. 100ml of deionized water was used to leach the soil column every 3 days, and the absorbance of the leaching liquid at 230nm was tested by UV-visible spectrophotometer to calculate the cumulative release of sodium alginate oligosaccharides.

[0122] The test results showed that the cumulative release rate of sodium alginate oligosaccharide in the polyvinyl alcohol-loaded sodium alginate oligosaccharide complex reached 50% after the first leaching, while that of the oligosaccharide-shellac complex group was only 6.14%. After the second leaching, the cumulative release rate of the former was 64%, and that of the latter was 8.38%. During the third leaching, the cumulative release rate of the polyvinyl alcohol-loaded complex rose to 72%, while that of the oligosaccharide-shellac complex was only 10.24%. After the tenth leaching, the cumulative release rate of the polyvinyl alcohol-loaded complex reached 88%, while that of the oligosaccharide-shellac complex was 33.24%.

[0123] These results indicate that the polyvinyl alcohol-loaded sodium alginate oligosaccharide complex has a poor effect in sustained release control and has an obvious burst release phenomenon, while the oligosaccharide-shellac complex exhibits a better sustained release effect, further demonstrating the advantages of shellac in controlling oligosaccharide release and promoting plant growth.

[0124] Wheat was selected as the experimental object and divided into three groups, each with 30 seeds, which were treated with polyvinyl alcohol loaded sodium alginate oligosaccharide, shellac loaded sodium alginate oligosaccharide and sodium alginate oligosaccharide control group at a concentration of 20ppm. The treated plants were planted in the same type of soil and placed in a constant temperature incubator for cultivation, providing the same growth conditions (temperature 25°C, relative humidity 80%). After 60 days of growth, the biomass (dry weight) of the plants was measured and the data was recorded.

[0125] Experimental results: The average biomass of the polyvinyl alcohol-loaded sodium alginate oligosaccharide treatment group was 22g. The average biomass of the shellac-loaded sodium alginate oligosaccharide treatment group was 30g. The average biomass of the sodium alginate oligosaccharide control group was 25g.

[0126] The results showed that the plant biomass of polyvinyl alcohol-loaded sodium alginate oligosaccharides was significantly lower than that of the control group loaded with shellac, which may be related to the burst release characteristics of polyvinyl alcohol-loaded materials. Since this material performs poorly in slow-release control, it is not suitable as a slow-release carrier for oligosaccharides. The experiment further proved the advantages of shellac in slow-release oligosaccharides and promoting plant growth, indicating that shellac has greater potential in this application field.

[0127] According to the comprehensive analysis of the experimental results of each embodiment, the oligosaccharide-shellac complex exhibits a significant growth-promoting effect in the growth process of different plants. Through solution spraying or root soaking treatment, the complex effectively increases the growth rate of plants, increases yield, and improves the quality of fruits or seeds. At the same time, the oligosaccharide-shellac complex also shows the ability to enhance the resistance of plants to abiotic stress. These results show that the oligosaccharide-shellac complex has potential application prospects in agricultural production and can provide a new and sustainable solution for improving the efficiency and quality of crop production.

[0128] For technicians in the professional field, it is obvious that the present invention is not limited to the specific details of the above-mentioned exemplary embodiments. Each implementation method does not only include a single technical solution, but a variety of possibilities under the guidance of the broad technical background and principles of the present invention. The description in this specification is intended to clearly explain the implementation methods of the invention, but not to limit its scope of application in detail. Technicians should regard this specification as a whole to understand the innovative spirit and basic principles of the present invention. Therefore, all modifications, equivalent substitutions or technical improvements made within the scope of protection of the present invention should be regarded as reasonable extensions of the present invention and are not limited to any specific embodiment. This flexibility ensures that the present invention can adapt to the ever-changing technical and application needs, so as to better realize its practical application and commercialization potential in agricultural production or other related fields.

Claims

1. A plant growth regulator containing shellac oligosaccharides, characterized in that: Including shellac, oligosaccharides, The weight ratio of shellac to oligosaccharide is 1:0.1-1:10, preferably 1:0.1-1:1, and more preferably 1:0.1-1:0.

5.

2. The plant growth regulator according to claim 1, characterized in that: The oligosaccharide and shellac are combined through hydrophobic interaction, hydrogen bond and the like, and contain no or additional auxiliary materials, wherein the auxiliary materials are selected from one or more of adhesives, thickeners, fillers or preservatives.

3. The plant growth regulator according to claim 2, characterized in that: The binder and thickener are selected from one or more of gum arabic, guar gum, xanthan gum, sodium polyacrylate and sodium carboxymethyl cellulose; The filler is selected from one or more inorganic fillers or organic fillers, the inorganic filler is selected from one or more talcum powder, diatomaceous earth and calcium powder, and the organic filler is selected from one or more cellulose, starch and lactose; The preservative is selected from one or more of sodium benzoate, potassium sorbate and parabens.

4. The plant growth regulator according to claim 1 or 2, characterized in that: The oligosaccharide is one or more of chitosan oligosaccharide, sodium alginate oligosaccharide or pectin oligosaccharide.

5. The plant growth regulator according to claim 1 or 2, characterized in that: The shellac is natural shellac or ethanol esterified modified shellac, and the ethanol esterified modified shellac is prepared by dissolving shellac in 4-5 times the amount of ethanol relative to the shellac, adding sulfuric acid with a mass concentration of 90%-98% relative to the mass of the shellac at 0.005-0.01 times as much as the mass of the shellac as a catalyst into the system, and heating and stirring at 70-80° C. for 5-8 hours.

6. A method for preparing the plant growth regulator according to any one of claims 1 to 5, comprising the following steps: a. 5-20 g of shellac is dissolved in 100-200 mL of a solvent, wherein the solvent is a 0.5% to 2% ammonia solution to obtain a shellac solution; b. Add 0.5-50 g of oligosaccharide to the shellac solution and stir at room temperature for 0.5-2 h until the oligosaccharide is completely dissolved and evenly dispersed to obtain an oligosaccharide-shellac complex solution; c. Drying the obtained oligosaccharide-shellac complex to obtain a powdery or granular oligosaccharide-shellac complex.

7. The method according to claim 6, characterized in that: The drying method is spray drying; The spray drying inlet temperature is 100-150°C, and the outlet temperature is 60-90°C.

8. A use of a plant growth regulator according to any one of claims 1 to 5, characterized in that : a. Disperse 0.1-5 g of the prepared oligosaccharide - shellac complex in 1-10 L of water to prepare an oligosaccharide - shellac dispersion solution; b. Spray the prepared solution evenly on one or more of the leaves, stems or roots of the plants, or soak the roots of the plants in the solution to promote plant growth.

9. The use according to claim 8, characterized in that: The plants are one or more of food crops, cash crops, vegetable crops, fruit trees or flower plants.

10. The use according to claim 8, characterized in that: The spraying or soaking step is performed at a key stage of plant growth, such as one or more of the germination stage, flowering stage or fruiting stage; Application methods can be adjusted according to crop type and growth stage to optimize growth regulation effects.