Plant biostimulant composition for increasing carotenoid content of fruits and vegetables and preparation and use methods thereof

Abstract

The invention provides a plant biostimulant composition for increasing the carotenoid content of fruits and vegetables as well as a preparation method and a use method of the plant biostimulant composition. The plant biostimulant composition is prepared from the following raw materials in parts by weight: 0.01 to 0.1 part of brassinolide (BR), 50 to 200 parts of sodium sulfite (Na2SO3), 1000 to 2000 parts of ammonium polyphosphate (APP), 50 to 200 parts of APP-manganese chelate (in terms of Mn element), 500 to 2000 parts of APP-magnesium chelate (in terms of Mg element) and 25 to 100 parts of organic silicon additive. The plant biostimulant composition is sprayed on the leaf surfaces of fruit trees, so that crop bodies can be stimulated to increase synthesis and storage of carotenoids, the content of the carotenoids in crops is increased, accumulation of flavor substances is increased, and the quality of fruits and vegetables is improved.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of agricultural planting, and specifically relates to a plant biological stimulant composition for increasing the carotenoid content of fruits and vegetables and a preparation and use method thereof. BACKGROUND

[0002] Carotenoids are a class of important fat-soluble natural pigments, are C40 or C30 terpenoids composed of isoprene skeleton, and are important secondary metabolites in plants. In addition to participating in biological processes such as photosynthesis, photoprotection and plant development, carotenoids can also impart various brilliant colors to flowers and fruits, and participate in the formation of aroma and flavor substances of flowers and fruits. Carotenoids are indispensable for the growth and development of plants, and are also very important for maintaining normal health and behavior of the human body. Some epidemiological studies have shown that eating vegetables and fruits containing carotenoids can provide the human body with precursors for vitamin A synthesis and antioxidants, which can help improve visual impairment, reduce the incidence of chronic diseases such as aging, cancer, cardiovascular disease, macular degeneration and neurodegenerative disease. Carotenoids are closely related to human health, but the human body cannot synthesize carotenoids itself and needs to rely on diet to obtain them. Therefore, increasing the carotenoid content in fruits and vegetables has become an important topic in modern agricultural research.

[0003] There are mainly two ways to increase the carotenoid content in fruits and vegetables: genetic breeding and cultivation management. Genetic breeding changes the genetic material of crops from the root, aiming to breed new varieties with significantly increased carotenoid content. However, genetic breeding has the disadvantages of long research and development cycle, high research and development cost, poor universality, and great limitations. It relies on available genetic variation within or between closely related species, and if there is a lack of high content genes in existing germplasm resources, it is difficult to achieve a breakthrough, resulting in this type of technology only being implemented in part of the plants, and not having universality for a wide variety of crops. Cultivation management optimizes the external environment and management measures to maximize the physiological potential of carotenoid synthesis without changing the genes of crops, which has the advantages of quick effect, no genetic modification concerns, and easy implementation. However, existing cultivation management techniques mostly focus on a certain link in the carotenoid synthesis pathway, and the limitation of other links in the synthesis pathway may affect the final synthesis of carotenoids, resulting in unstable effects when used in different crops and different application environments, which limits the application of this type of technology in agricultural production. There is no publicly reported technical solution that integrates the entire carotenoid synthesis pathway, is suitable for various fruits and vegetables, and can significantly increase the carotenoid content at low cost. SUMMARY

[0004] In order to solve the problems in the prior art, the present application provides a plant biological stimulant composition for increasing the carotenoid content of fruits and vegetables and a preparation and use method thereof. By spraying the plant biological stimulant composition on the leaves of fruit trees, the synthesis and storage of carotenoids in the crops can be stimulated, the content of carotenoids in the crops can be increased, the accumulation of flavor substances can be increased, and the quality of fruits and vegetables can be improved.

[0005] The technical problem of the present application is solved by adopting the following technical scheme: The first object of the present application is to provide a plant biological stimulant composition for increasing the carotenoid content of fruits and vegetables, which comprises brassinolide (BR), sodium sulfite (Na2SO3), ammonium polyphosphate (APP), APP-manganese chelate, APP-magnesium chelate and an organic silicon adjuvant.

[0006] Further, the plant biological stimulant composition for increasing the carotenoid content of fruits and vegetables comprises the following raw materials by weight: Brassinolide (BR) 0.01-0.1 parts Sodium sulfite (Na2SO3) 50-200 parts Ammonium polyphosphate (APP) 1000-2000 parts APP-manganese chelate 50-200 parts (calculated as Mn element) APP-magnesium chelate 500-2000 parts (calculated as Mg element) Organic silicon adjuvant 25-100 parts.

[0007] Further, the organic silicon adjuvant is a soluble powder of polyethylene glycol siloxane copolymer. Preferably, the organic silicon adjuvant is a soluble powder of polyether-modified trisiloxane.

[0008] Further, the degree of polymerization of the ammonium polyphosphate is 2-6. Preferably, the degree of polymerization of the ammonium polyphosphate is 4-6.

[0009] Further, the plant biological stimulant composition for increasing the carotenoid content of fruits and vegetables comprises the following raw materials by weight: Brassinolide (BR) 0.03-0.08 parts Sodium sulfite (Na2SO3) 80-160 parts Ammonium polyphosphate (APP) 1300-1800 parts APP-manganese chelate 80-160 parts (calculated as Mn element) APP-magnesium chelate 800-1500 parts (calculated as Mg element) Organic silicon adjuvant 50-80 parts.

[0010] The second objective of this invention is to provide a method for preparing a plant biostimulant composition that increases the carotenoid content of fruits and vegetables, comprising the following steps: S1. Prepare an ammonium polyphosphate aqueous solution and adjust the pH of the solution to 6.0~8.0. Divide the ammonium polyphosphate aqueous solution into two portions, and add Mn dropwise to each portion while stirring. 2+ soluble salt solutions, Mg 2+ The soluble salt solution was heated until a precipitate began to form. After filtration, anhydrous ethanol was added to the solution. After the precipitation was complete, the solution was centrifuged and dried to obtain APP-manganese chelate and APP-magnesium chelate, respectively, for later use. S2. Weigh brassinolide, sodium sulfite, ammonium polyphosphate, APP-manganese chelate, APP-magnesium chelate, and organosilicon additive according to the proportion, pulverize and mix evenly to obtain a plant biostimulant composition.

[0011] Furthermore, the reaction temperature for preparing APP-manganese chelate and APP-magnesium chelate is 5~30℃.

[0012] Furthermore, the degree of polymerization of the ammonium polyphosphate is 2 to 6.

[0013] Furthermore, the pH of the solution is adjusted by adding ammonia.

[0014] Furthermore, the Mn 2+ The soluble salt is selected from any one of manganese sulfate, manganese chloride, and manganese nitrate; the Mg 2+ The soluble salt is selected from any one of magnesium sulfate, magnesium chloride, and magnesium nitrate.

[0015] Furthermore, a method for preparing a plant biostimulant composition for increasing the carotenoid content of fruits and vegetables includes the following steps: S1, Preparation of chelates Dissolve ammonium polyphosphate in water and stir thoroughly to form an aqueous solution. Adjust the pH of the APP solution to 6.0-8.0 by adding ammonia dropwise. Under magnetic stirring, slowly add Mn to the APP solution. 2+ The soluble salt solution was monitored in situ using a focused beam reflectometer (FBRM) to track the changes in particles in the solution in real time. When insoluble matter was detected, APP and Mn were... 2+ Once the chelation reaction is complete, the addition is stopped; the product is filtered to obtain a clear APP-manganese chelate solution; then excess anhydrous ethanol is added to the solution, and after the chelate has completely precipitated, it is separated by centrifugation and then dried at low temperature to obtain a solid APP-manganese chelate for later use; Using a general method to Mn 2+ The soluble salt solution was replaced with Mg 2+ A soluble salt solution was used to obtain a solid APP-magnesium chelate. S2. Preparation of plant biostimulant composition Weigh brassinolide, sodium sulfite, ammonium polyphosphate, APP-manganese chelate, APP-magnesium chelate, and organosilicon additive according to the specified proportions, pulverize and mix them evenly to obtain a plant biostimulant composition.

[0016] The third objective of this invention is to provide a method for using a plant biostimulant composition that increases the carotenoid content of fruits and vegetables, comprising the following steps: preparing the plant biostimulant composition into an aqueous solution and then applying it to the leaves during the fruit enlargement period and / or color change period.

[0017] Furthermore, the concentration of the aqueous solution of the plant biostimulant composition is 1.63~4.5 g / L.

[0018] Furthermore, the concentration of the aqueous solution of the plant biostimulant composition is 2~4.125 g / L.

[0019] Furthermore, the plant biostimulant composition is applied at a rate of 30-40L per acre, and sprayed 2-3 times.

[0020] Furthermore, there should be an interval of 7 to 10 days between each spraying.

[0021] Furthermore, spraying should be done on cloudy days or on sunny days before 10 a.m. or after 3 p.m.

[0022] Furthermore, the plant biostimulant composition can be used to increase the carotenoid content of leafy, root, fruit, and legume plants.

[0023] This invention increases brassinolide (BR), activates the entire carotenoid synthesis pathway, upregulates the gene expression of multiple key enzymes in the carotenoid synthesis pathway through signal transduction, catalyzes the rate-limiting first step of carotenoid synthesis, induces the expression of sucrose transport protein (SUC / SUT), and promotes the transport of sugar to the fruit.

[0024] Increasing sodium sulfite (Na2SO3) inhibits photorespiration, reduces the loss of photosynthetic products, increases the supply of carbon skeleton, promotes the upregulation of key enzyme genes such as PSY (phytoene synthase), promotes the flow of more GGPP (geraniyl pyrophosphate) to carotenoid synthesis, and through the effect of antioxidant stress, mild oxidative stress upregulates the antioxidant system (such as SOD) and promotes the accumulation of carotenoids (natural antioxidants).

[0025] Adding ammonium polyphosphate (APP) provides phosphorus in a long-lasting, slow-release manner. Phosphorus is a component of energy carriers such as ATP and NADPH, participates in photosynthesis (Calvin cycle) and sugar metabolism, and provides the phosphorus skeleton for carotenoid synthesis, indirectly but crucially promoting carotenoid synthesis.

[0026] The addition of APP-manganese chelate is necessary because the activity of GGPP synthase in the carotenoid synthesis process requires Mn. 2+ Yes. Carotenoids are derived from glucose, the initial product of photosynthesis, through the isoprene biosynthesis pathway in plants. Mn 2+ The presence or absence of Mn is a key factor determining whether it is metabolized as a carotenoid or as other isoprene products, increasing Mn 2+ It can significantly increase the content of carotenoids.

[0027] Adding APP-magnesium chelate is beneficial because magnesium is the central atom in chlorophyll molecules and participates in photophosphorylation and carboxylation reactions in chloroplasts, playing a crucial role in chlorophyll synthesis and photosynthesis. Supplementing with Mg is also recommended. 2+ It can promote chlorophyll synthesis, increase chlorophyll content, and improve photosynthetic efficiency. Efficient photosynthesis can provide energy, abundant carbon skeletons, and precursor substances for the synthesis of carotenoids.

[0028] Adding organosilicon adjuvants can significantly enhance the adhesion, penetration, and diffusion of plant biostimulant compositions on leaf surfaces when applied as foliar sprays, thereby improving absorption efficiency.

[0029] The plant biostimulant composition is stored and transported in powder form, which can effectively reduce transportation costs and reduce the decrease in the mass concentration of trace elements in the chelated state caused by the hydrolysis and decomposition of ammonium polyphosphate chelates.

[0030] Compared with the prior art, the beneficial technical effects of the present invention are as follows: This invention's plant biostimulant composition combines hormone synergy with nutrient fortification. Applied via foliar spraying, it first activates the entire carotenoid synthesis pathway, influencing the flow of carbon and phosphorus sources in the pigment synthesis pathway towards carotenoid synthesis. Furthermore, by supplementing with ammonium polyphosphate and ammonium polyphosphate-micronutrient chelates, it enhances photosynthesis, increases the supply of carbon and phosphorus skeletons for carotenoid synthesis precursors, and increases the supply of key micronutrients that promote the synthesis of rate-limiting enzymes in carotenoids. This facilitates the metabolic transformation of intermediate products in the plant isoprene biosynthesis pathway towards carotenoids, thereby effectively promoting the synthesis and accumulation of carotenoids and increasing the carotenoid content in fruits and vegetables.

[0031] The plant biostimulant composition of the present invention can stimulate fruits and vegetables to increase the synthesis and storage of carotenoids, increase the content of carotenoids in fruits and vegetables, and at the same time increase the accumulation of flavor substances.

[0032] The plant biostimulant composition of this invention has the characteristics of small dosage and high activity. After spraying, it can significantly improve the quality of fruits and vegetables, and achieve the goal of improving the economic benefits of farmland with low input cost.

[0033] The plant biostimulant composition of this invention uses inexpensive and readily available raw materials, while yielding high output, thus improving the economic benefits of farmland with low input costs.

[0034] The plant biostimulant composition of the present invention can be stored and transported at room temperature, is simple to operate, and is easy to use and promote.

[0035] The above description is merely an overview of the technical solution of the present invention. In order to better understand the technical means of the present invention and to implement it in accordance with the contents of the specification, and to make the above and other objects, features and advantages of the present invention more apparent and understandable, specific embodiments of the present invention are described below. Detailed Implementation

[0036] The technical solution of the present invention will be further described in detail below with reference to specific embodiments. It should be understood that the following embodiments are merely illustrative and explanatory of the present invention and should not be construed as limiting the scope of protection of the present invention. All technologies implemented based on the above content of the present invention are covered within the scope of protection intended by the present invention.

[0037] In addition, unless otherwise specified, all raw materials, reagents, instruments and equipment used in this invention can be obtained by purchasing from the market or prepared by existing methods.

[0038] It should be noted that, in order to more accurately describe the composition of the biostimulant composition in this invention, the amount of chelate added is measured in terms of the amount of metal ions.

[0039] For example, the amount of APP-manganese chelate added to the composition is based on the amount of Mn added. 2+ The amount of APP-magnesium chelate added is measured based on the amount of Mg added. 2+ The quantity is used as the standard for measurement.

[0040] Example 1: Preparation of a plant biostimulant composition for increasing carotenoid content in fruits and vegetables A method for preparing a plant biostimulant composition for increasing the carotenoid content of fruits and vegetables includes the following steps: Preparation of S1, APP-manganese chelate Dissolve 50g of ammonium polyphosphate (degree of polymerization 4-6) in 950g of water, stirring thoroughly until dissolved. Adjust the pH of the APP solution to 7.0 by adding ammonia dropwise. Under conditions of pH 7.0, temperature 5℃, and magnetic stirring, slowly add manganese sulfate solution dropwise to the APP solution using a burette. Simultaneously, use an FBRM (Focused Beam Reflectance Meter) to monitor the changes in particles in the solution in real time under in-situ conditions. When insoluble matter is detected, the reaction between APP and Mn... 2+ The chelation reaction was complete. The addition of manganese sulfate solution was stopped, and the titration volume of the manganese sulfate solution was recorded. The product was filtered through an acid-resistant funnel to obtain a clear APP-manganese chelate solution. Excess anhydrous ethanol was added to the solution, and after the chelate precipitated, it was separated by centrifugation and then dried at low temperature to obtain a solid APP-manganese chelate. The weight of the chelate was determined by the amount of Mn added dropwise. 2+ The quality is used as the standard for measurement.

[0041] Preparation of S2, APP-magnesium chelates The preparation and measurement of APP-magnesium chelate are the same as in step S1, except that the addition of manganese sulfate solution is replaced with the addition of magnesium sulfate solution to obtain solid APP-magnesium chelate. The mass of solid APP-magnesium chelate is determined by the amount of Mg added. 2+ The quality is used as the standard for measurement.

[0042] S3. Preparation of plant biostimulant composition 0.05g of brassinolide, 100g of sodium sulfite, 1500g of ammonium polyphosphate, 100g of APP-manganese chelate (calculated as Mn), 1000g of APP-magnesium chelate (calculated as Mg), and 50g of soluble powder of polyether-modified trisiloxane were weighed in sequence, pulverized and mixed to obtain a plant biostimulant composition powder.

[0043] Example 2: Preparation of a plant biostimulant composition for increasing carotenoid content in fruits and vegetables Unlike Example 1, the plant biostimulant composition comprises: 0.01g brassinolide, 200g sodium sulfite, 1000g ammonium polyphosphate, 200g APP-manganese chelate (calculated as Mn), 500g APP-magnesium chelate (calculated as Mg), and 100g polyether-modified trisiloxane soluble powder.

[0044] When preparing APP-manganese chelate and APP-magnesium chelate, the pH of the solution was adjusted to 6.0 and the reaction temperature was 5℃.

[0045] Example 3: Preparation of a plant biostimulant composition for increasing carotenoid content in fruits and vegetables Unlike Example 1, the plant biostimulant composition comprises: 0.1g brassinolide, 50g sodium sulfite, 2000g ammonium polyphosphate, 50g APP-manganese chelate (calculated as Mn), 2000g APP-magnesium chelate (calculated as Mg), and 25g polyether-modified trisiloxane soluble powder.

[0046] When preparing APP-manganese chelate and APP-magnesium chelate, the pH of the solution was adjusted to 8.0 and the reaction temperature was 30℃.

[0047] Example 4: Application of plant biostimulant composition in carrots The 600-mu carrot functional agriculture experimental base was divided into 6 equal zones, with 200cm protective rows set up in each zone. Two experimental groups (Group 1, Group 2, and Control Group) were established. Group 1 and Group 2 were treated with foliar spraying of the plant biostimulant described in this embodiment, while the Control Groups were treated with foliar spraying of purified water. The carrot varieties, fertilization, planting time, pesticides, and routine field management were identical in all zones.

[0048] Management of plant biostimulant composition spraying: The plant biostimulant composition obtained in Example 1 of this invention is dissolved in purified water and then diluted to 1000L to obtain a plant biostimulant composition solution. The amount prepared according to this method is sufficient for one spraying, and the solution is prepared again within three days before spraying.

[0049] Spray treatment during carrot growth: Two rounds of foliar spraying were applied to carrots in the experimental group during the fruit enlargement period, with a one-week interval between the two sprayings. The carrots in Experiment 2 were sprayed with foliar sprays three times during the fruit enlargement period. There was a one-week interval between the first and second rounds of spraying, and a ten-day interval between the third and second rounds of spraying.

[0050] The control group of carrots underwent two rounds of foliar spraying during the fruit enlargement period, with a one-week interval between the two sprayings.

[0051] When spraying, the amount of spraying per acre is 30L, and the spraying time is chosen to be after 5 pm on cloudy days or sunny days.

[0052] The growth of carrots in six zones was observed. Compared with the control group, the carrots in experimental groups 1 and 2 grew vigorously, with large, flat, dark green leaves that were thicker; the flesh was a bright orange.

[0053] After the carrots matured and were harvested uniformly, the carrots from each group were sent to SGS Shanghai for testing. The test results after averaging the data within each group are shown in Table 1.

[0054] Table 1 Comparison of nutritional components between the carrot experimental group and the control group The tests showed that carrots treated with the plant biostimulant composition of this application had significantly higher carotenoid content compared with the control group. The carotenoid content of the first experimental group, which was sprayed twice, was 253.8% higher than that of the control group, and the carotenoid content of the second experimental group, which was sprayed three times, was 406.7% higher than that of the control group. The antioxidant performance was greatly improved, and the carrots did not oxidize and turn brown four hours after being cut.

[0055] Example 5: Application of plant biostimulant composition in tomatoes The 160-mu tomato functional agriculture experimental base was divided into 8 equal zones, with 400cm protective rows in each zone. Six experimental groups and two control groups were established. The experimental groups were treated with the plant biostimulant described in this embodiment via foliar spraying, while the control groups were treated with purified water via foliar spraying. The tomato varieties, fertilization, planting time, pesticides, and routine field management were identical across all zones.

[0056] Management of plant biostimulant composition spraying: The plant biostimulant composition obtained in Example 2 of this invention is dissolved in purified water and then diluted to 1000L to obtain a plant biostimulant composition solution. The solution is prepared in sufficient quantity for one application according to the method, and the solution is prepared again within three days before the application.

[0057] During the tomato growth period, spraying treatment was applied, with the same spraying method used in both the experimental and control groups: Apply one round of foliar spray to tomatoes during the fruit enlargement stage, using 30L per acre; apply two rounds of foliar spray to tomatoes during the color-changing stage, with a one-week interval between the two rounds, using 40L per acre. The interval between foliar spraying during the fruit enlargement stage and foliar spraying during the color-changing stage is one week.

[0058] Spraying should be done on cloudy days or after 5 p.m. on sunny days.

[0059] The growth of tomatoes in eight zones was observed. Compared with the control group, the experimental group's tomato leaves were oily green and darker in color; the fruit color and taste of the tomatoes were further improved.

[0060] After the tomatoes were harvested uniformly when they were ripe, the tomatoes from each group were sent to SGS Shanghai for testing. The test results after averaging the data within each group are shown in Table 2.

[0061] Table 2 Comparison of nutritional components between the experimental and control groups of tomatoes Tests showed that tomatoes treated with the plant biostimulant composition of this application had significantly higher carotenoid content compared to the control group, with the experimental group showing a 318.8% increase in carotenoid content compared to the control group.

[0062] Example 6: Application of Plant Biostimulant Composition in Satsuma Mandarins The 400-mu (approximately 66.7 hectares) functional agriculture experimental base for tangerines was divided into four equal zones, with each zone having a 200cm protective row. Two experimental groups and two control groups were established. The experimental groups were treated with foliar spraying of the plant biostimulant described in this embodiment, while the control groups were treated with foliar spraying of purified water. The tangerine varieties, fertilization, planting time, pesticides, and daily field management were the same in all zones.

[0063] Management of plant biostimulant composition spraying: The plant biostimulant composition obtained in Example 3 of this invention is dissolved in purified water and then diluted to 1000L to obtain a plant biostimulant composition solution. The amount prepared according to this method is sufficient for one spraying, and the solution is prepared again within three days before spraying.

[0064] Spraying treatment was applied during the growth period of the mandarin oranges, with the same spraying method used in both the experimental and control groups: Apply foliar spray to the tangerines once during the fruit enlargement stage, using 30L per acre; apply foliar spray again during the color-changing stage, using 30L per acre. There should be a one-week interval between the foliar spraying during the fruit enlargement stage and the foliar spraying during the color-changing stage.

[0065] Spraying should be done on cloudy days or after 5 p.m. on sunny days.

[0066] The growth of mandarin oranges in four zones was observed. Compared with the control group, the mandarin oranges in the experimental group grew vigorously and remained a bright green color during the harvest period. The leaves were darker and greener than those in the control group.

[0067] After the tangerines matured and were harvested uniformly, the tangerines from each group were sent to SGS Shanghai for testing. The test results after averaging the data within each group are shown in Table 3.

[0068] Table 3 Comparison of nutritional components between the experimental group and the control group of mandarin oranges Tests showed that the carotenoid content of the tangerines treated with the plant biostimulant composition of this application was significantly increased compared with the control group. The carotenoid content of the experimental group was 447.6% higher than that of the control group. At the same time, the taste was better, which not only increased the carotenoid content but also improved the quality of the tangerines.

[0069] The sequence numbers of the above embodiments of the present invention are for descriptive purposes only and do not represent the superiority or inferiority of the embodiments.

[0070] The embodiments of the present invention have been described above, but the present invention is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many other forms under the guidance of the present invention without departing from the spirit and scope of the claims, and these forms are all within the protection scope of the present invention.

Claims

1. A plant biostimulant composition for increasing the carotenoid content of fruits and vegetables, characterized in that, Including the following parts by weight of raw materials: Brassinolide (BR) 0.01~0.1 parts Sodium sulfite (Na2SO3) 50~200 parts Ammonium polyphosphate (APP) 1000~2000 parts 50-200 parts of APP-manganese chelate (calculated as Mn element) APP-magnesium chelate 500~2000 parts (based on elemental Mg) 25-100 parts of organosilicon additive.

2. The plant biostimulant composition for increasing the carotenoid content of fruits and vegetables as described in claim 1, characterized in that: The organosilicon additive is a soluble powder of polyethylene glycol siloxane copolymer.

3. The plant biostimulant composition for increasing the carotenoid content of fruits and vegetables as described in claim 1, characterized in that: The degree of polymerization of the ammonium polyphosphate is 2 to 6.

4. A method for preparing a plant biostimulant composition for increasing the carotenoid content of fruits and vegetables according to any one of claims 1-3, characterized in that, Includes the following steps: S1. Prepare an ammonium polyphosphate aqueous solution and adjust the pH of the solution to 6.0~8.

0. Divide the ammonium polyphosphate aqueous solution into two portions, and add Mn dropwise to each portion while stirring. 2+ soluble salt solutions, Mg 2+ The soluble salt solution was heated until a precipitate began to form. After filtration, anhydrous ethanol was added to the solution. After the precipitation was complete, the solution was centrifuged and dried to obtain APP-manganese chelate and APP-magnesium chelate, respectively, for later use. S2. Weigh brassinolide, sodium sulfite, ammonium polyphosphate, APP-manganese chelate, APP-magnesium chelate, and organosilicon additive according to the proportion, pulverize and mix evenly to obtain a plant biostimulant composition.

5. The method for preparing a plant biostimulant composition for increasing the carotenoid content of fruits and vegetables as described in claim 4, characterized in that: The reaction temperature for preparing APP-manganese chelate and APP-magnesium chelate is 5~30℃.

6. A method of using a plant biostimulant composition for increasing the carotenoid content of fruits and vegetables according to any one of claims 1-3, characterized in that, Includes the following steps: After preparing the plant biostimulant composition into an aqueous solution, apply it as a foliar spray during the fruit enlargement and / or color change stages.

7. The method of using the plant biostimulant composition for increasing the carotenoid content of fruits and vegetables as described in claim 6, characterized in that: The concentration of the aqueous solution of the plant biostimulant composition is 1.63~4.5g / L.

8. The method of using the plant biostimulant composition for increasing the carotenoid content of fruits and vegetables as described in claim 6, characterized in that: The plant biostimulant composition is applied at a rate of 30-40L per acre, and sprayed 2-3 times.

9. The method of using the plant biostimulant composition for increasing the carotenoid content of fruits and vegetables as described in claim 6, characterized in that: There should be an interval of 7 to 10 days between each spraying.

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