Application of astragalus extract containing astragalus polysaccharide in promoting plant growth

Abstract

The invention belongs to the technical field of agriculture, and particularly relates to application of an astragalus extract containing astragalus polysaccharide in promoting plant growth. Purified astragalus polysaccharide is proved to have good growth regulation and stress resistance enhancement functions on plants, but the extraction and purification process of the polysaccharide is high in cost and low in efficiency, the requirement of large-scale production is difficult to meet, and the application of the astragalus polysaccharide in agriculture is limited. The invention provides an application of an astragalus extract containing astragalus polysaccharide, and particularly relates to an application of the astragalus extract as a plant growth promoter for promoting plant growth and improving stress resistance of plants, reducing the use concentration of the astragalus polysaccharide, promoting the application of the astragalus polysaccharide in agriculture, and providing a new choice for regulating and controlling plant growth in agriculture.

Description

Technical Field

[0001] The priority information of the present invention is as follows: priority number is 202311488571X, priority date is November 9, 2023, the invention name is "Application of Astragalus Polysaccharide in Promoting Plant Growth", and the disclosure of which is incorporated herein by reference. The present invention belongs to the field of agricultural technology, and specifically relates to the application of an Astragalus extract containing Astragalus Polysaccharide in promoting plant growth. Background Art

[0002] Astragalus is a herb with a long history and a wide range of clinical applications. It is one of the most commonly used Chinese medicines in Chinese medicine throughout the ages. Astragalus was first recorded as a medicine in Shennong's Herbal Classic. Its original name was "Huangqi" and it was listed as a top-grade medicine. It has been recorded in many later herbal books. It has the effects of replenishing qi and strengthening the exterior, promoting diuresis and expelling toxins, draining pus, and healing sores and promoting tissue regeneration. Westerners began to recognize the medical value of Astragalus in the 19th century. It was first reported by Dr Alexander Von Bange, a doctor who studied East Asian plants in 1868. In 1911, in China's Raw Materials, G.A. Stuart believed that Astragalus "has a good reputation as a tonic, cough suppressant, and diuretic."

[0003] Astragalus polysaccharides have a wide range of biological activities, and their research is mainly concentrated in the fields of traditional Chinese medicine, animal husbandry and agriculture. In the mid-1980s, An Jinhua, Karen S. Liu, Edwin S. Linax, John H. Muser and others from Pan-China, a world-renowned botanical medicine research and development institution, spent 10 years screening out astragalus polysaccharides purified from the higher plant astragalus from nearly 30 Chinese herbal medicines in the Chinese pharmacopoeia, which have the ability to comprehensively and continuously increase whole blood cells, stimulate the hematopoietic system and enhance the body's immunity. Later studies found that purified astragalus polysaccharides can promote plant growth and development and improve the plant's own resistance. For example, in the paper "Research on the Extraction of Astragalus Polysaccharides and Its Effect on Improving Plant Resistance" published by Qiu Benjun, it was found that 10 mg / mL (10000 ppm) of purified astragalus polysaccharides (purity above 90%) can increase the germination rate of seeds, 1 mg / mL (1000 ppm) of purified astragalus polysaccharides can promote the growth of seedling roots, 0.1 mg / mL (100 ppm) of purified astragalus polysaccharides can increase the chlorophyll content of plant leaves, and 0.1-1 mg / mL (100-1000 ppm) of purified astragalus polysaccharides can enhance the plant's resistance to stress.

[0004] Astragalus polysaccharide has a wide range of pharmacological effects and is a valuable immunopotentiator. It has a significant protective effect on target organs and can counteract the adverse reactions of radiotherapy and chemotherapy. In addition, astragalus polysaccharide has the effects of comprehensively increasing whole blood cells, regulating the body's immune function and anti-tumor, and is widely used in the medical field. In the agricultural field, purified astragalus polysaccharide has been proven to have good growth regulation and enhanced stress resistance for plants, but the extraction and purification process of polysaccharides requires highly specialized technology and equipment, with high extraction costs and low efficiency, which makes it difficult to meet the needs of large-scale production, limiting its application in agriculture. Summary of the invention

[0005] Astragalus polysaccharide, which is rich in content in the astragalus extract, is the active ingredient therein. In addition, it also contains at least one active ingredient of saponins, flavonoids, amino acids, alkaloids, monosaccharides, proteins, trace elements, etc. The present invention has found that the astragalus extract can have a significant promoting effect on plant growth at low concentrations of polysaccharides, and also increases the stress resistance of plants. Compared with the prior art, the present invention has a simple extraction process and low cost. The synergistic effect between the components in the extract can greatly reduce the use concentration of astragalus polysaccharide, promote the application of astragalus polysaccharide, and also provide a new option for regulating plant growth in agriculture.

[0006] The invention provides application of an astragalus extract containing astragalus polysaccharide in promoting plant growth.

[0007] An astragalus extract for promoting plant growth, the astragalus extract comprises at least one of an astragalus water extract, an astragalus water-extracted alcohol precipitate, and an astragalus extract with an ethanol content greater than 0 and less than or equal to 60%. The astragalus extract has astragalus polysaccharide as a marker component and is effective within a concentration range of 0.01-1000ppm.

[0008] The astragalus extract includes astragalus polysaccharide and at least one saponin, flavonoids, amino acids, alkaloids, monosaccharides, proteins, and trace elements; preferably, the astragalus water extract includes astragalus polysaccharide, monosaccharide, protein, amino acids, Fe, Cu, Zn, K, and Ca as active ingredients.

[0009] In the present invention, the promoting of plant growth includes promoting plant germination, promoting the growth of one or more of roots, stems, leaves or flowers and fruits. For example, promoting the growth of root length, stem thickness, plant height, leaf width, leaf length, leaf number, leaf area, biomass, chlorophyll content, yield, etc.

[0010] In the present invention, the astragalus extract is used as an active ingredient of the growth promoter and can be used alone or in combination with other products.

[0011] The invention provides a plant growth promoter. The astragalus extract comprises at least one of an astragalus water extract, an astragalus water-extracted alcohol precipitate, and an astragalus extract with an ethanol content greater than 0 and less than or equal to 60%. The astragalus extract uses astragalus polysaccharide as a marker component and is effective within a concentration range of 0.01-1000ppm.

[0012] The "growth promoter" mentioned in the present invention refers to a plant growth promoter, which is a biologically active substance that can promote cell division, differentiation and elongation growth, or promote the growth of plant vegetative organs and the development of reproductive organs.

[0013] In the present invention, the astragalus extract containing astragalus polysaccharide is a natural plant growth promoter.

[0014] The plants described in the present invention include but are not limited to economic crops and food crops, such as tobacco, corn, lettuce, wheat, pepper, Chinese cabbage, lettuce, bok choy, tomato, citrus, kiwi, cherry, pear, apple, cotton, cucumber, eggplant, etc.

[0015] The so-called "economic crops" are of various types, including but not limited to fiber crops (such as cotton, hemp, etc.), oil crops (such as sesame, peanuts, etc.), sugar crops (such as sugarcane, sugar beets, etc.), hobby crops (tobacco), medicinal crops, dye crops, ornamental crops, fruits (such as citrus, kiwi, cherry, pear, apple, etc.) and other economic crops (such as lettuce, pepper, Chinese cabbage, lettuce, Shanghai green), etc.

[0016] The “food crops” mentioned above include, but are not limited to, cereal crops (wheat, rice, corn), tuber crops (including sweet potatoes, potatoes, etc.) and legume crops (including soybeans, broad beans, peas, mung beans, etc.).

[0017] In the product of the present invention, the astragalus extract can be directly used as a single dose. In order to make it stable and easy to transport and store, it can be made into an agricultural product, for example, by adding auxiliary materials to make a corresponding dosage form. The auxiliary materials can be conventional auxiliary materials in the field, for example, dispersants, wetting agents, binders, emulsifiers, stabilizers, solvents, etc.

[0018] On the other hand, the astragalus extract of the present invention can be used as a synergist in combination with foliar fertilizers, water-soluble fertilizers, compound fertilizers, pesticides and other products.

[0019] In the present invention, the dosage form of the agricultural product includes but is not limited to emulsifiable concentrate, suspension concentrate, wettable powder, dust, granule, aqueous solution, mother liquor or mother powder.

[0020] In the present invention, when used, the single agent or agricultural product prepared from the astragalus extract is used to treat seeds, spray leaves or irrigate roots.

[0021] In the present invention, when the astragalus extract or its product is prepared into a solution for promoting seed germination or plant growth, the concentration of astragalus polysaccharide in the solution can be selected according to actual needs.

[0022] For example, it can be selected from 0.01-2000ppm, 0.01-1000ppm, 0.01-500ppm, or 0.01ppm, 0.02ppm, 0.03ppm, 0.1ppm, 0.2ppm, 0.3ppm,

[0023] 1.0ppm, 2.0ppm, 3.0ppm, 10ppm, 20ppm, 30ppm and so on.

[0024] The seeds are treated by mixing a single agent or agricultural product made of the astragalus extract with the seeds to coat the seeds with the extract, or soaking the seeds to be germinated with the extract solution.

[0025] In the growth promotion experiment of the present invention, the influence of diseases and insect pests on plant growth has been excluded. Through such an experimental design, the results are sufficient to show that the effect of Astragalus extract on promoting plant growth is not caused by avoiding diseases and insect pests.

[0026] The present invention also provides an application of an astragalus extract containing astragalus polysaccharide in regulating plant stress resistance. The astragalus extract includes at least one of an astragalus water extract, an astragalus water-extracted alcohol precipitate, and an astragalus extract with an ethanol content greater than 0 and less than or equal to 60%. The astragalus extract contains astragalus polysaccharide as an active ingredient and is effective at a concentration within the range of 0.01-1000ppm.

[0027] Plant stress resistance refers to certain traits that plants possess to resist adverse environments, such as cold resistance, drought resistance, salt resistance, high temperature resistance, waterlogging resistance, and UV damage resistance.

[0028] In the present invention, the astragalus extract containing astragalus polysaccharide regulates the stress resistance of plants including at least one of salt resistance, cold resistance, drought resistance, high temperature resistance, waterlogging resistance, and UV damage resistance.

[0029] Beneficial effects of the invention: Compared with the prior art, the invention has a simple extraction process and low cost. The synergistic effect between the components in the extract can greatly reduce the concentration of astragalus polysaccharides, promote the application of astragalus polysaccharides, and also provide a new option for regulating plant growth in agriculture.

[0030] The content of astragalus polysaccharide in the astragalus extract applicable to the present invention can be selected from 10%-50%. DETAILED DESCRIPTION

[0031] The technical solution of the present invention is described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0032] Seed germination rate = (number of germinated seeds / number of test seeds) × 100%;

[0033] Seed germination potential = (number of seeds germinated at the peak of germination / number of seeds tested) × 100%;

[0034] Root length: The distance from the rhizome junction to the root tip is the root length of this plant;

[0035] Plant height: the distance from the base of the plant to the tip of the topmost expanded leaf (i.e. the total length of the plant).

[0036] Example 1 Preparation of Astragalus Extract

[0037] Wash and slice the Astragalus, place it in a forced air drying oven to dry, and then grind it into fine powder with a crusher for later use.

[0038] 1) Preparation of Astragalus water-extraction alcohol precipitate: Weigh a certain amount of Astragalus, add 10 times the volume of water, stir and extract at 50°C for 120 minutes, repeat the above operation, combine the two extraction filtrates, centrifuge at 4000 rpm for 15 minutes, take the supernatant, pass through a 100 kDA ceramic membrane, and rotate and concentrate at 55°C to 1 / 4 of the original volume, add 5 times the volume of anhydrous ethanol, precipitate at 4°C overnight, filter and obtain the precipitate, and freeze-dry to obtain Astragalus polysaccharide water-extraction alcohol precipitate, and the polysaccharide concentration is determined to be 50%.

[0039] 2) Preparation of Astragalus water extract: Weigh a certain amount of Astragalus, add 10 times the volume of water, stir and extract at 50°C for 120 minutes, repeat the above operation, combine the two extraction filtrates, centrifuge at 4000rmp / min for 15min, take the supernatant, pass through a 100kDA ceramic membrane, and rotate and concentrate at 55°C to a concentrate with a solid content of 40-50%. The polysaccharide content was determined to be 30%.

[0040] 3) Preparation of 20% ethanol Astragalus extract: Weigh a certain amount of Astragalus, add 10 times the volume of 20% (v / v) ethanol, stir and extract at 50°C for 120 minutes, repeat the above operation, combine the two extraction filtrates, centrifuge at 4000 rpm for 15 minutes, take the supernatant, pass through a 100 kDA ceramic membrane, and rotate and concentrate at 55°C to a concentrate with a solid content of 40-50%. The polysaccharide content was determined to be 25%.

[0041] 4) Preparation of 40% ethanol Astragalus extract: Weigh a certain amount of Astragalus, add 10 times the volume of 40% (v / v) ethanol, stir and extract at 50°C for 120 minutes, repeat the above operation, combine the two extraction filtrates, centrifuge at 4000 rpm for 15 minutes, take the supernatant, pass through a 100 kDA ceramic membrane, and rotate and concentrate at 55°C to a concentrate with a solid content of 40-50%. The polysaccharide content was determined to be 18%.

[0042] 5) Preparation of 60% ethanol Astragalus extract: Weigh a certain amount of Astragalus, add 10 times the volume of 40% (v / v) ethanol, stir and extract at 50°C for 120 minutes, repeat the above operation, combine the two extraction filtrates, centrifuge at 4000 rpm for 15 minutes, take the supernatant, pass through a 100 kDA ceramic membrane, and rotate and concentrate at 55°C to a concentrate with a solid content of 40-50%. The polysaccharide content was determined to be 10%.

[0043] Example 2 Experiment on promoting growth of rice seeds by soaking with different astragalus extracts

[0044] 1. Experimental design

[0045] The experimental samples were different astragalus extracts in Example 1, which were prepared with water to form a mother solution with a polysaccharide concentration of 1% (i.e., 10,000 ppm). The rice seeds were soaked after the agent was diluted with water according to the concentration designed in Table 1 to test the growth-promoting effects of different astragalus extracts on rice.

[0046] Table 1 Experimental design

[0047]

[0048] 2. Experimental methods

[0049] Rice seeds were disinfected with 5% sodium hypochlorite for 15 minutes, rinsed with clean water 6-7 times, and the surface moisture was dried with filter paper. According to the experimental design, astragalus polysaccharide was prepared with water to 0.01-100ppm, and the seeds were soaked with different concentrations of agents. The amount of agents should not cover the seeds, and the seeds were soaked at 25℃ for 16 hours. Wash with clean water 3-4 times to wash off the agent on the surface of the seeds, and dry the surface moisture for later use. The seeds soaked with the agent were sown in a disposable square culture dish filled with planting soil, 36 seeds were sown in each culture dish, and at least 3 replicates were set for each treatment. When sowing, full and intact seeds were selected, each seed was pressed to the bottom of the culture dish, and then the surface was gently pressed and smoothed, the lid was covered, and it was placed in a 25℃ culture room for cultivation. The light intensity was set to 10000Lux, and the time period was set to 14 hours of light and 10 hours of darkness. After 3 days, the number of germinations in each treatment group was investigated, and the germination potential was calculated. After 7 days, the aboveground part was cut off to measure the length of the seedling buds.

[0050] 3. Experimental results

[0051] The experimental results are shown in Table 2. From the experimental results, it can be seen that different astragalus extracts have different degrees of growth-promoting effects on rice seed soaking at concentrations of 0.1-100ppm. Among them, the optimal growth-promoting concentrations of astragalus water extract, astragalus water extract alcohol precipitate, 20% ethanol astragalus extract and 40% ethanol astragalus extract are 1ppm, and the optimal growth-promoting concentration of 60% ethanol astragalus extract is 10ppm. There are differences in the growth-promoting effects of each extract. From the perspective of rice germination potential and sprout length indicators, the order of effect strength is astragalus water extract > 20% ethanol astragalus extract > 40% ethanol astragalus extract > astragalus water extract alcohol precipitate > 60% ethanol astragalus extract.

[0052] Table 2 Results of promoting rice growth by soaking seeds with different astragalus extracts

[0053]

[0054]

[0055] Example 3 Experiment on the effect of different astragalus extracts on the low temperature resistance of cucumber

[0056] 1. Experimental design

[0057] The experimental samples were different Astragalus extracts in Example 1, which were prepared with water to form a mother solution with a polysaccharide concentration of 1% (i.e., 10,000 ppm). The cucumbers were sprayed with leaves after the agent was diluted with water according to the concentration designed in Table 3 to test the anti-low temperature effects of different Astragalus extracts on cucumbers.

[0058] Table 3 Experimental design

[0059]

[0060] 2. Experimental methods

[0061] Select cucumber seedlings with consistent growth, prepare different concentrations of pesticides, spray the cucumber seedlings on the leaves, control the number of sprays per pot, make the liquid medicine evenly distributed on the leaf surface but not dripping, to ensure the same amount of spraying for each treatment, and set up 6 pots of seedlings for each treatment. After spraying, each treatment continued to be cultured in a 25℃ culture room, and after 24 hours of seedling acclimatization, it was placed in a 4℃ low-temperature chamber overnight for low temperature stress. After 16 hours, the leaves of each treatment began to lose water and wilt. Cut off the first true leaf of each seedling to measure the fresh weight of the leaves. After each leaf fully absorbed water in water for 24 hours, the surface water was dried, and the saturated fresh weight of the leaves was measured again to calculate the water loss rate of the leaves.

[0062]

[0063] 4. Experimental results

[0064] The experimental results are shown in Table 4. From the experimental results, it can be seen that different Astragalus extracts at a concentration of 0.1-100ppm for foliar spraying of cucumber can improve the low temperature resistance of cucumber seedlings to varying degrees, but there are differences in the effects. From the experimental results, it can be seen that the order of the effects of each extract is: Astragalus water extract > 20% ethanol Astragalus extract > 40% ethanol Astragalus extract > Astragalus water extract alcohol precipitation > 60% ethanol Astragalus extract, among which Astragalus water extract has the best effect. At the optimal concentration of 1ppm, the water loss rate of cucumber leaves is 18.11%, which is significantly lower than the water loss rate of leaves in the CK treatment group (31.21%), indicating that the Astragalus water extract can significantly improve the low temperature resistance of cucumber seedlings.

[0065] Table 4 Effects of different astragalus extracts on low temperature resistance of cucumber

[0066]

[0067]

[0068] Example 4 Experiment on promoting tomato seed germination by astragalus water extract and pure astragalus polysaccharide

[0069] From Examples 2 and 3, it can be seen that among the different Astragalus extracts, the effects of the Astragalus water extract in promoting growth and resisting stress are better than those of other extracts. Studies have reported that Astragalus polysaccharide is the main component of Astragalus, and two Astragalus polysaccharide purifications with a purity of more than 90% have been obtained through separation and purification. In addition, Astragalus also contains a variety of active ingredients such as rich amino acids, proteins, monosaccharides, and trace elements that are beneficial to plant growth. This example compares the growth-promoting activity of Astragalus water extract and Astragalus polysaccharide purification through a tomato seed germination experiment.

[0070] 1. Experimental samples

[0071] Experimental samples: Astragalus water extract was obtained from Example 1, and the results of the determination of each component are shown in Table 5. The polysaccharide contents of purified astragalus polysaccharide A and purified astragalus polysaccharide B were 92% and 95%, respectively, and the preparation methods were based on the paper "Study on the Extraction of Astragalus Polysaccharide and Its Effect on Improving Plant Resistance" published by Qiu Benjun.

[0072] Table 5 Determination results of various components in Astragalus membranaceus water extract

[0073] Test items Measurement results Polysaccharides 30％ Monosaccharides 13.1％ protein 8.2％ Amino Acids 10.3％ Fe 7.3mg / 100g Cu 0.3mg / 100g Zn 6.5mg / 100g K 85.2mg / 100g Ca 56.9mg / 100g

[0074] 2. Experimental Design

[0075] The experimental sample was prepared with water to form a mother solution with a polysaccharide concentration of 1% (i.e., 10000 ppm). After the agent was diluted with water according to the concentration designed in Table 6, tomato seeds were soaked to test the germination-promoting effect of the astragalus water extract and the purified astragalus polysaccharide on tomato seeds.

[0076] Table 6 Experimental design

[0077]

[0078] 3. Experimental methods

[0079] Select plump tomato seeds of uniform size and design the experiment according to Table 6. Soak the seeds for 4 h with water (CK), 0.1, 1, 10, 100, 1000 and 10000 ppm of the agent, respectively. Clean the agent on the surface of the seeds with water and place them in a germination box padded with two filter papers. Place 60 seeds in each germination box to ensure that the seeds are evenly distributed. Set up 3 replicates for each treatment and place them in a culture room at 25°C. Record the number of seeds germinated every day, and calculate the germination potential after 3 days and the germination rate after 7 days.

[0080] 3. Experimental results

[0081] The experimental results are shown in Table 7. It can be seen from the experimental results that the germination potential and germination rate of tomatoes in the CK control treatment group were 78.18% and 91.21% respectively. After treatment with the Astragalus water extract, the germination of tomato seeds can be significantly promoted in the concentration range of 0.1-100ppm. The optimal concentration is 1ppm. At this concentration, the germination potential and germination rate of tomatoes are 87.78% and 99.14% respectively, which are significantly higher than the CK control. When the polysaccharide concentration reaches 10000ppm, it shows an inhibitory effect on tomato seed germination. Both Astragalus polysaccharide purified products A and B show a trend of increasing promotion effect with increasing polysaccharide concentration. The promotion effect is not obvious in the low concentration range of 0.1-10ppm, but it has a significant promotion effect at the high concentration of 100-10000ppm. When the purity of the polysaccharide purified product reaches 10000ppm, the effect is the best. This test result is consistent with the test results in the paper "Study on the Extraction of Astragalus Polysaccharides and Its Effect on Improving Plant Resistance". From the above results, it can be seen that the Astragalus extract of the present invention has a significant effect on promoting tomato seed germination within a relatively low polysaccharide concentration range (0.1-100ppm). This may be because the Astragalus extract contains other active ingredients in addition to polysaccharides. The synergistic effect between the ingredients greatly reduces the effective concentration of polysaccharides, making the Astragalus water extract show a significant growth-promoting effect.

[0082] Table 7 Results of promoting tomato seed germination by Astragalus water extract and purified Astragalus polysaccharide

[0083]

[0084] Example 5 Experiment on drought resistance of wheat by water extract of Astragalus membranaceus and pure polysaccharide

[0085] The experimental samples were the same as those in Example 4. The experimental samples were prepared with water to form a mother liquor with a polysaccharide concentration of 1% (i.e., 10,000 ppm). The wheat seeds were soaked after being diluted with water according to the concentration designed in Table 8 to test the drought resistance effect of the astragalus water extract and the purified astragalus polysaccharide on wheat.

[0086] Table 8 Experimental design

[0087]

[0088]

[0089] 3. Experimental methods

[0090] Select plump and uniform-sized wheat seeds, soak them in water (CK), 0.1, 1, 10, 100, 1000 and 10000 ppm of agents for 16 hours, wash the agent on the surface of the seeds with water for later use. Put two filter papers in the germination box, add 15 mL of 17% (m / v) PEG6000 solution on the filter paper to simulate drought conditions, and take the treatment group with 15 mL of clean water as the non-stress control. Place 30 seeds in each germination box to evenly distribute the seeds. Set 3 replicates for each treatment and place them in a culture room at 25°C for culture. After 7 days, investigate the number of germinations in each treatment group, calculate the germination rate, and measure the root length and shoot length of wheat.

[0091] 4. Experimental results

[0092] The experimental results are shown in Table 9. It can be seen from the experimental results that the germination rate of wheat seeds under non-stress conditions reached 99.39%, the root length of wheat seedlings was 11.23 cm, and the bud length was 12.39 cm. Under PEG6000 simulated drought conditions, the germination rate was 58.18%, the root length of wheat seedlings was 7.01 cm, and the bud length was 8.26 cm. The growth and germination of wheat were both under obvious stress. After being treated with Astragalus water extract and Astragalus polysaccharide purification, the resistance of wheat under drought conditions can be improved. Similar to the results of tomato seed germination promotion, Astragalus water extract can significantly improve the drought resistance of wheat in the concentration range of 0.1-100ppm. The optimal concentration is 1ppm. At this concentration, the germination rate reached 78.14%, the root length of wheat seedlings was 8.93 cm, and the bud length was 9.78 cm, which was significantly better than the CK control. When the polysaccharide concentration reached 10000ppm, it also showed an inhibitory effect. Purified astragalus polysaccharides A and B both have significant promoting effects at concentrations of 10-10000ppm, and the effect is best when the purity of the purified polysaccharide reaches 100ppm. From the above results, it can be seen that at the same polysaccharide content, the astragalus water extract of the present invention has a significant effect of promoting wheat germination under drought conditions within a lower polysaccharide concentration range (0.1-100ppm), and the optimal concentration of the astragalus water extract is significantly lower than that of the purified astragalus polysaccharide, and the effect is equivalent to that of the purified astragalus polysaccharide, which may be related to the synergistic enhancement between the active ingredients in the astragalus water extract.

[0093] Table 9 Results of Astragalus water extract and purified Astragalus polysaccharide on drought resistance of wheat

[0094]

[0095]

[0096] Example 6 Trial production of Astragalus extract preparation

[0097] The formulation includes: Astragalus membranaceus water extract, thickener-xanthan gum, dispersant-alkyl glycoside, defoaming agent and water. The specific formula design is shown in Table 10, and the trial production is carried out according to the following steps:

[0098] Table 10 Trial formulation of Astragalus membranaceus aqueous extract preparation

[0099]

[0100] ① Weigh an appropriate amount of xanthan gum and an appropriate amount of water and shear until the xanthan gum is completely dissolved and dispersed to form a uniform liquid for later use;

[0101] ② The liquid in ① is stirred at 55° C., and the astragalus extract is accurately weighed and added into a stirring kettle, and stirred at 55° C. for 30 min until the liquid is homogeneous;

[0102] ③ Weigh alkyl polyglycoside and add it to the above ② homogeneous liquid, stir for 3 minutes; then add defoaming agent and stir for 3 minutes to complete the trial preparation of the formula sample.

[0103] After trial production of each formulation, the samples were subjected to high temperature (54°C) and low temperature (0°C) storage stability tests, and the formulation stability investigation was conducted after the samples were stored in hot and cold conditions for 2 weeks.

[0104] The results showed that the sample of Formulation 1 was turbid under hot storage conditions; the sample of Formulation 2 showed obvious stratification without adding a dispersant; the sample of Formulation 3 had a lot of foam during the dissolution process, and the sample of Formulation 4 was a homogeneous stable liquid with good dispersibility. Formulation 4 was tested, and the test indicators and results are shown in Table 12.

[0105] Table 11 Test results of Astragalus membranaceus multi-water extract preparations

[0106] Detection indicators Test results pH 5.73 Water insoluble matter, % ≤2％ Polysaccharide content, % 1.51％ Monosaccharides 0.6％ protein 0.4％ Amino Acids 0.5％ Fe 0.3mg / 100g Cu 0.01mg / 100g Zn 0.32mg / 100g K 4.1mg / 100g Ca 2.8mg / 100g

[0107] Example 7 Experiment on promoting the growth of Chinese cabbage by spraying the leaves of Astragalus membranaceus aqueous extract

[0108] 1. Experimental design

[0109] The experimental sample was the Astragalus membranaceus aqueous extract preparation in Example 6 (polysaccharide content was 15000 ppm). After the agent was diluted according to the concentration designed in Table 12, it was sprayed on the leaves of Chinese cabbage to test the growth-promoting effect of the Astragalus membranaceus aqueous extract preparation on Chinese cabbage.

[0110] Table 12 Experimental design

[0111]

[0112] 2. Experimental methods

[0113] Select pakchoi seedlings (two true leaves) with uniform growth, prepare the astragalus extract preparation with water to 0.1-10ppm according to the experimental design, spray the pakchoi leaves so that the solution is evenly distributed on the leaf surface but does not drip, place them in a culture room for cultivation, and set the temperature to 25°C. There are 6 seedlings in each treatment group. The water and fertilizer management of each treatment group is consistent during the experiment. After 7 days, the SPAD value, fresh weight and leaf area of ​​the leaves in different treatment groups were investigated.

[0114] 3. Experimental results

[0115] The experimental results are shown in Table 13. From the experimental results, it can be seen that spraying the Astragalus water extract preparation on the leaves of Chinese cabbage can significantly promote the growth of Chinese cabbage. The promotion effect is significant in the range of 0.1-1ppm, and the optimal concentration is 1ppm. Under this concentration treatment, the SPAD value of Chinese cabbage slices can be significantly improved, the accumulation of chlorophyll can be promoted, and the increase in the fresh weight and leaf area of ​​Chinese cabbage can be significantly promoted. Compared with the clear water control, the promotion rate of the Astragalus water extract preparation on the fresh weight and leaf area of ​​Chinese cabbage is 37.62% and 21.87%.

[0116] Table 13 Results of leaf spraying of Astragalus membranaceus water extract to promote growth of Chinese cabbage

[0117]

[0118] Example 7 Experiment on the effect of Astragalus membranaceus aqueous extract on tomato root irrigation and growth promotion

[0119] 1. Experimental design

[0120] The experimental sample was the Astragalus membranaceus aqueous extract preparation (polysaccharide content of 15,000 ppm) in Example 6. After the agent was diluted according to the concentration designed in Table 14, the tomato roots were irrigated to test the growth-promoting effect of the Astragalus membranaceus aqueous extract preparation on tomato root irrigation.

[0121] Table 14 Experimental design

[0122]

[0123] 2. Experimental methods

[0124] Tomato seedlings (4 true leaves) with uniform growth were selected, and the astragalus extract preparation was prepared with water at a concentration of 0.1-10ppm according to the experimental design. The roots were irrigated from the bottom of the pot with 100mL per pot. The pots were placed in a culture room for cultivation with the temperature set at 25°C. There were 6 pots of seedlings in each treatment group. The water and fertilizer management of each treatment group was consistent during the experiment. The plant weight, root weight and stem diameter of the different treatment groups were investigated after 10 days.

[0125] 3. Experimental results

[0126] The experimental results are shown in Table 15. From the experimental results, it can be seen that the Astragalus water extract preparation can significantly promote the growth of tomatoes by root irrigation. The promotion effect is significant in the range of 0.1-1ppm. The optimal root irrigation concentration is 1ppm. Under this concentration treatment, the stem thickness of tomatoes can be significantly increased, and the accumulation of tomato biomass can be significantly promoted. Compared with the clear water control, the promotion rates of the Astragalus polysaccharide preparation treatment group on tomato stem thickness, plant weight and root weight were 12.83%, 27.29% and 23.13%, respectively.

[0127] Table 15 Results of root irrigation of astragalus extract preparation to promote tomato growth

[0128]

[0129] Example 8 Field test on the effect of root irrigation treatment of Astragalus membranaceus aqueous extract preparation and organic compound fertilizer on lettuce growth

[0130] Test crop: Lettuce (variety: Xiayou No. 10)

[0131] 1. Experimental design

[0132] The experimental sample was the Astragalus water extract preparation in Example 6 (polysaccharide content was 15,000 ppm). After the agent was diluted according to the concentration designed in Table 16, the lettuce was irrigated with roots to test the field growth-promoting effect of the Astragalus water extract preparation on lettuce.

[0133] Table 16 Experimental design

[0134]

[0135] 2. Experimental methods

[0136] The experiment set up three concentration treatments, each with three replicate plots, each with 150 plants, and each plant was quantitatively irrigated with 150 ml of root fertilizer, with compound fertilizer (NPK: 24-10-16) as base fertilizer. Ten plants were randomly selected from each plot 10 days after root irrigation to investigate plant height, root length, biomass, SPAD value and leaf number.

[0137] 3. Experimental results

[0138] The experimental results are shown in Table 17. From the experimental results, it can be seen that root irrigation of lettuce with a mixture of Astragalus water extract and organic compound fertilizer in the field can significantly promote the growth of lettuce. The promotion effect is significant within the range of 0.1-1ppm, and the optimal concentration is 1ppm. At this concentration, the SPAD value and the number of leaves of lettuce seedlings can be significantly increased. Compared with the clear water control, the plant height and plant weight promotion rates are as high as 23.93%, and the plant weight promotion rates are as high as 19.54%.

[0139] Table 17 Results of the effect of Astragalus extract preparation on the growth promotion of lettuce

[0140]

[0141] Example 9 Field test on the effect of mixed root irrigation of Astragalus membranaceus aqueous extract preparation and foliar fertilizer on pepper growth

[0142] Test crop: pepper (variety: Erjingtiao)

[0143] 1. Experimental design

[0144] The experimental sample was the Astragalus membranaceus aqueous extract preparation in Example 6 (polysaccharide content was 15000 ppm). After the agent was diluted according to the concentration designed in Table 18, it was sprayed on the leaves of peppers to test the field growth-promoting effect of the Astragalus membranaceus aqueous extract preparation on peppers.

[0145] Table 18 Experimental design

[0146]

[0147] 2. Experimental methods

[0148] The experiment set up three concentration treatments, each with three replicate plots, with a total of 150 pepper plants in the three plots. The first foliar spraying was carried out on different treatment groups at the seedling stage, and the second foliar spraying was carried out before the flowering stage. The liquid was evenly distributed and it was advisable not to drip. It was mixed with foliar fertilizer (15-15-15) during spraying. The later agricultural operations were carried out according to the habits of farmers, and phenotypic trait surveys were conducted regularly. Fifteen plants with consistent growth were selected for tracking in each plot, and basic trait surveys were conducted before spraying. The stem thickness, plant height, leaf length and leaf width were measured 15 days after foliar spraying, and the growth rate was calculated. The number of flowers and fruiting conditions were investigated during the flowering and fruiting periods.

[0149] 3. Experimental results

[0150] The experimental results are shown in Tables 19 and 20. It can be seen from the experimental results that the use of the Astragalus water extract preparation in the field for foliar spraying at the pepper seedling stage can promote the growth of pepper seedlings, and foliar spraying at the pre-flowering stage can promote the flowering and fruiting of peppers. It has a significant promoting effect in the range of 0.1-1ppm, and the optimal concentration is 1ppm. At the optimal concentration, the pepper seedling stem diameter growth rate reached 9.77%, the plant height growth rate reached 48.89%, the leaf length growth rate reached 11.89%, and the leaf width growth rate reached 4.70%, which was significantly better than the clear water control. At the optimal concentration, the pepper flower number increased by 17.76% and the fruit number increased by 18.18% when the pesticide was applied at the pre-flowering stage.

[0151] Table 19 Results of Astragalus extract preparation on pepper growth promotion

[0152]

[0153] Table 20 Effects of Astragalus extract preparation on flowering and fruiting of pepper

[0154]

[0155] Example 10 Field test of the water extract of Astragalus membranaceus on regulating the growth of citrus

[0156] Test crop: Five-year-old citrus (variety: Chunjian)

[0157] 1. Experimental design

[0158] The experimental sample was the astragalus extract preparation in Example 6 (polysaccharide content was 15000 ppm). After the agent was diluted according to the concentration designed in Table 21, it was sprayed on the leaves of citrus during the fruit swelling period to test the field growth promotion and fruit swelling effect of the astragalus water extract preparation on citrus.

[0159] Table 21 Experimental design

[0160]

[0161] 2. Experimental methods

[0162] The experiment set up three concentration treatments, and each treatment set up three replicate plots (plot area: 7m*7m=49m 2 ), with one row in the middle of each plot to avoid interference, and 4 fruit trees were marked in each plot. During the fruit expansion period of citrus, the different treatment groups were sprayed on the leaves, with the liquid evenly distributed and not dripping. The later agricultural operations and drug use habits were carried out according to the farmers' habits. After 45 days of experimental treatment, 25 fruits and leaves were randomly selected from 4 fruit trees in each plot to investigate the horizontal and vertical diameters of citrus fruits, single fruit weight, and leaf SPAD values.

[0163] 3. Experimental results

[0164] The experimental results are shown in Table 22. From the experimental results, it can be seen that the use of Astragalus water extract preparation for foliar spraying during the citrus fruit swelling period can promote the accumulation of chlorophyll in citrus leaves and promote fruit swelling. It shows obvious promoting effects at concentrations of 0.1-1ppm. The optimal concentration is 1ppm. At this concentration, the SPAD value of the leaves can be significantly improved, and the fruit swelling can be promoted. Compared with the clear water control, the single fruit weight increased by 16.98%, the fruit transverse diameter increased by 10.95%, and the fruit longitudinal diameter increased by 14.29%.

[0165] Table 22 Effects of Astragalus membranaceus aqueous extract preparations on citrus growth and fruit swelling

[0166]

[0167] Example 11 Experiment on the effect of Astragalus membranaceus aqueous extract on cotton salt resistance

[0168] 1. Experimental design

[0169] The experimental sample was the astragalus extract preparation in Example 6 (polysaccharide content was 15000 ppm). The cotton was treated after the agent was diluted according to the concentration designed in Table 23 to test the salt resistance effect of the astragalus water extract preparation on cotton.

[0170] Table 23 Experimental design

[0171]

[0172] 2. Experimental methods

[0173] The ratio of nutrient soil and vermiculite is 1:1 (g / g), and after mixing evenly, it is used as planting soil. 300g of planting soil is weighed into the planting box, and a NaCl aqueous solution with a concentration of 0.8% is prepared. According to the experimental design, the agent is prepared with a NaCl aqueous solution to different concentrations, and 250mL is added to each planting box. The treatment with 250mL of NaCl aqueous solution is used as the stress control (CK), and the treatment with 250mL of clean water is used as the non-stress control. Stir evenly and set aside. 20 cotton seeds are evenly sown in each germination box, the planting depth is kept consistent, the lid is covered, and 3 replicates are set for each treatment. They are placed in a culture room at 25°C for cultivation, and the lid is opened when the cotton seedlings emerge from the soil surface. After 5 days, the cotton seedling rate of each treatment group is counted (based on the complete expansion of two cotyledons). After 7 days, the seedlings are taken out for measurement. 15 seedlings are taken from each treatment group to measure the plant height and root length.

[0174] 3. Experimental results

[0175] The experimental results are shown in Table 24. From the experimental results, it can be seen that the growth of cotton seedlings was significantly inhibited under 0.8% NaCl salt stress, and the seedling rate, plant height and root length were significantly lower than those of the non-stress control group. After treatment with different concentrations of Astragalus polysaccharides, the salt stress on cotton seedlings was alleviated, the seedling rate of cotton under salt stress was improved, and the growth of the aboveground and underground parts was promoted. The optimal concentration was 1 ppm. Under this concentration treatment, the cotton seedling rate was significantly improved, the plant height growth rate reached 27.55%, and the root length growth rate reached 17.07%.

[0176] Table 24 Effect of Astragalus extract preparation on cotton resistance to salt stress

[0177]

[0178] Example 12 Experiment on the effect of Astragalus membranaceus aqueous extract on waterlogging resistance of eggplant

[0179] 1. Experimental design

[0180] The experimental sample was the astragalus extract preparation in Example 6 (polysaccharide content was 15000 ppm). After the agent was diluted according to the concentration designed in Table 25, the eggplant was sprayed with leaves to test the effect of the astragalus water extract preparation on the waterlogging resistance of eggplant.

[0181] Table 25 Experimental design

[0182]

[0183] 3. Experimental methods

[0184] Eggplant seedlings (2-3 true leaves) with uniform growth were selected. A total of 5 treatment groups were set up in the experiment. Each treatment group was subjected to waterlogging stress. The water layer on the soil surface was maintained at 1-2 cm for waterlogging treatment. On the day of waterlogging, different concentrations of pesticides were sprayed on each treatment group to ensure uniform distribution of the pesticide solution. The group sprayed with clean water was used as the stress control (CK). At the same time, the normal irrigation treatment group was set as the non-stress control (sprayed with clean water). The plant height, stem thickness and aboveground fresh weight of the eggplant seedlings were measured after 14 days.

[0185] 4. Experimental results

[0186] The experimental results are shown in Table 26. It can be seen from the experimental results that under normal irrigation conditions, the height of eggplant seedlings is 25.21 cm, the stem diameter is 3.34 cm, and the aboveground fresh weight is 11.86 g. Under waterlogging stress, the height, stem diameter and aboveground fresh weight of eggplant seedlings are 12.34 cm, 2.13 cm and 5.73 g, respectively, and the growth of seedlings is significantly inhibited. Foliar spraying of 0.1-10 ppm of Astragalus membranaceus water extract can significantly promote the growth of eggplant seedlings under waterlogging stress. The optimal concentration is 1 ppm. At this concentration, compared with the CK control, the growth rate of eggplant seedlings in height is 30.39%, the growth rate of stem diameter is 28.17%, and the growth rate of aboveground fresh weight is 20.24%.

[0187] Table 26 Effect of Astragalus extract preparation on waterlogging resistance of eggplant

[0188]

[0189] Example 13 Field test of the effect of Astragalus membranaceus aqueous extract on high temperature resistance of corn

[0190] Test crops: corn (variety: MY73, 4250 plants / acre)

[0191] 1. Experimental design

[0192] The experimental sample is the astragalus extract preparation in Example 6 (polysaccharide content is 15000ppm), and the agent is diluted according to the concentration designed in Table 27 and then sprayed on the corn. High temperature will affect the pollination of corn, resulting in reduced yield, and too high temperature will cause corn bald tip. In this example, the corn in the flowering period is sprayed on the leaves during the high temperature period to test the field high temperature resistance effect of the astragalus water extract preparation on corn.

[0193] Table 27 Experimental design

[0194]

[0195]

[0196] 2. Experimental methods

[0197] The experiment set up three concentration treatments, and each treatment set up three replicate plots (plot area: 5m*6m=30m 2 ), each plot was separated by one row to avoid mutual interference. During the high temperature period, different treatment groups were sprayed on the leaves during the flowering period to make the liquid evenly distributed and not dripping. The water spraying treatment was used as the CK control group. The later agricultural operations and drug use habits were carried out according to the farmers' habits. When the corn was harvested, 50 plants were randomly selected from each treatment to peel and calculate the bald tip rate, and 10 plants with the same leaves were selected to measure the SPAD value, and the theoretical yield per mu was calculated by weighing.

[0198] Theoretical yield per mu (kg) = average single plant weight (g) × number of plants per mu (4250) / 1000.

[0199] 3. Experimental results

[0200] The experimental results are shown in Table 28. From the experimental results, it can be seen that foliar spraying of corn with 0.1-10ppm of Astragalus water extract preparation during high temperature can improve the high temperature resistance of corn to varying degrees. The optimal concentration is 1ppm. At this concentration, the SPAD value of corn leaves can be significantly improved, promoting its growth. The bald tip rate is significantly lower than that of the CK control. At harvest, the per-acre yield of corn increased by 6.54% compared with the CK control, indicating that the Astragalus water extract preparation can significantly improve the high temperature resistance of corn.

[0201] Table 28 Effect of Astragalus membranaceus aqueous extract preparation on high temperature resistance of corn

[0202]

[0203] Example 13 Field test of astragalus extract preparation on wheat resistance to dry hot wind

[0204] Test crop: wheat (variety: Jimai 22)

[0205] 1. Experimental design

[0206] The experimental sample is the astragalus extract preparation (polysaccharide content is 15,000ppm) in Example 6, and the preparation is diluted according to the concentration designed in Table 29 and then sprayed on the wheat leaves. Dry hot wind is a disastrous weather during the grain filling and ripening period of wheat in the northern wheat-growing areas, which causes the water balance in the wheat body to be lost, metabolic activities to be blocked, photosynthesis cannot be carried out normally, the grain filling process is shortened, and the wheat yield is seriously affected. According to the weather conditions, this embodiment sprays the wheat leaves in the grain filling period before the dry hot wind comes, so as to test the effect of the astragalus water extract preparation on the field resistance to dry hot wind of wheat.

[0207] Table 29 Experimental design

[0208]

[0209] 2. Experimental methods

[0210] The experiment set up three concentration treatments, and each treatment set up three replicate plots (plot area: 4m*5m=20m 2 ), a protective row was set in the middle of each plot to avoid mutual interference. During the grain filling period, the leaves of different treatment groups were sprayed 2 days before the arrival of dry hot wind according to weather conditions to make the liquid evenly distributed and not dripping. The water spraying treatment was used as the CK control group. The later agricultural operations and drug use habits were carried out according to the farmers' habits. The number of grains per ear, thousand-grain weight and yield were investigated at harvest time.

[0211] 3. Experimental results

[0212] The experimental results are shown in Table 30. From the experimental results, it can be seen that 2 days before the arrival of dry hot wind, foliar spraying of 0.1-10ppm Astragalus water extract preparation on wheat in the filling period can improve the wheat's resistance to dry hot wind, among which 1ppm has the best effect. At this concentration, the number of wheat grains increased by 29.30% compared with the CK control, and the thousand-grain weight increased by 22.15%, which had a significant promoting effect on wheat yield, indicating that the Astragalus water extract preparation has a significant effect on wheat's resistance to dry hot wind.

[0213] Table 30 Effect of Astragalus membranaceus aqueous extract preparation on wheat resistance to dry hot wind

[0214]

[0215] Example 14 Field test of Astragalus membranaceus aqueous extract preparation to prevent citrus sunburn damage

[0216] Test crops: Citrus (variety: Ehime)

[0217] 1. Experimental design

[0218] The experimental sample is the Astragalus extract preparation in Example 6 (polysaccharide content is 15,000 ppm), and the agent is diluted according to the concentration designed in Table 31 and then sprayed on the whole plant of citrus. Sunburn of citrus is more serious in July and August. Sunburn is a common physiological disease of citrus, also known as "sun fruit". Continuous exposure to strong sunlight and strong UV stress will hinder the growth of citrus peel and mesophyll, and the Ehime variety has a thin skin and is easily sunburned. In this example, the whole plant of Ehime is sprayed before high temperature to test the effect of the Astragalus water extract preparation on preventing citrus sunburn damage.

[0219] Table 31 Experimental design

[0220]

[0221] 2. Experimental methods

[0222] The experiment set up three concentration treatments, and each treatment set up three replicate plots (plot area: 7m*7m=49m 2 ), with one row in the middle of each plot to avoid interference with each other, mark 5 fruit trees in each plot, spray the whole citrus trees (citrus is not bagged) before high temperature, so that the liquid medicine is evenly distributed without dripping, and the treatment of spraying with clean water is the CK control group. Later agricultural operations and drug use habits are carried out according to farmers' habits.

[0223] 3. Experimental investigation method

[0224] During the high temperature period, the sunburn of citrus was observed, the number of sunburned fruit trees in each plot was counted, and the average sunburn rate of the fruit was calculated. The sunburned fruits in each plot were graded, and the degree of sunburn damage to the fruits in different treatment groups was compared. The grading standard for the degree of sunburn damage to citrus is shown in Table 32. It was observed that the sunburned parts of citrus initially showed small gray-green or yellow-brown spots, which then gradually expanded to form round or irregular gray-brown dry scars. The growth of the skin of the diseased part stagnated, the texture became hard and rough, and sometimes cracked, making the fruit shape irregular. For those with mild damage, the burns were limited to the skin, and for those with severe damage, the juice cells were damaged, the juice was very little and tasteless, the skin texture became hard, the capsule lost water, the capsule wall became corky, and finally the fruit lost its edible value.

[0225] Table 32 Grading standards for the degree of sunburn damage to citrus

[0226]

[0227]

[0228] 4. Experimental results

[0229] The experimental results are shown in Table 33. It can be seen from the experimental results that during the high temperature period, 33.03% of the CK control citrus fruits were sunburned. After the citrus was treated with 0.1-10ppm of Astragalus water extract before the high temperature, the burn rate of citrus was significantly reduced. Among them, the burn rate of citrus at a concentration of 1ppm was the lowest, at 25.21%, followed by a concentration of 10ppm, with a burn rate of 26.39%. The burn rate of citrus at a concentration of 0.1ppm was 27.96%, which was significantly lower than the CK control. From the perspective of different levels of damage to citrus, the damage degree of citrus in the CK treatment group was concentrated in grades III-V, among which the number of fruits with a damage degree of IV was the largest, reaching 11.42%. After using Astragalus polysaccharide water extract, the damage degree of citrus was concentrated in grades II-III, and the damage degree of citrus was also significantly lower than the CK control. This indicates that applying an aqueous extract of Astragalus before high temperatures can prevent sunburn damage to citrus, reduce the degree of burns on citrus during high temperatures, and reduce the overall sunburn rate of citrus. The best effect is achieved at a concentration of 1 ppm.

[0230] Table 33 Effect of Astragalus membranaceus aqueous extract preparation on the degree of sunburn damage in citrus

[0231]

[0232] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. Application of astragalus extract containing astragalus polysaccharide in promoting plant growth.

2. An Astragalus extract for promoting plant growth, characterized in that: The astragalus extract comprises at least one of an astragalus water extract, an astragalus water-extracted alcohol precipitate, and an astragalus extract with an ethanol content greater than 0 and less than or equal to 60%. The astragalus extract has astragalus polysaccharide as a marker component, and its concentration is effective within the range of 0.01-1000ppm.

3. The astragalus extract according to claim 2, characterized in that The astragalus extract includes astragalus polysaccharide and at least one saponin, flavonoids, amino acids, alkaloids, monosaccharides, proteins, and trace elements; Preferably, the astragalus water extract comprises astragalus polysaccharides, monosaccharides, proteins, amino acids, Fe, Cu, Zn, K, and Ca as active ingredients.

4. The use according to claim 1, characterized in that: The promoting plant growth includes promoting seed germination, and / or promoting the growth of one or more of roots, stems, leaves, or flowers and fruits.

5. The use according to claim 1, characterized in that: When in use, the astragalus extract is made into an agricultural product, and the agricultural product also includes auxiliary materials, which are one or more of a dispersant, a wetting agent, a binder, an emulsifier, a stabilizer, and a solvent.

6. The use according to claim 5, characterized in that: The dosage form of the product is emulsifiable concentrate, suspension, wettable powder, dust, granule, aqueous solution, mother liquid or mother powder.

7. The application according to claim 6, characterized in that: The agricultural product made from the astragalus extract is used in combination with foliar fertilizer, water-soluble fertilizer and compound fertilizer.

8. The use according to claim 7, characterized in that: When using, a single dose of Astragalus extract or the prepared agricultural product is used to treat seeds, spray leaves or irrigate roots.

9. A plant growth promoter, characterized in that The plant growth promoter comprises astragalus extract, which comprises at least one of astragalus water extract, astragalus water-extracted alcohol precipitation, and astragalus extract with an ethanol content greater than 0 and less than or equal to 60%. Astragalus polysaccharide is used as a marker component in the astragalus extract, and is effective within a concentration range of 0.01-1000ppm.

10. Application of astragalus extract containing astragalus polysaccharide in regulating plant stress resistance, the astragalus extract comprising at least one of astragalus water extract, astragalus water-extracted alcohol precipitate, and astragalus extract with an ethanol content greater than 0 and less than or equal to 60%, the astragalus extract having astragalus polysaccharide as a marker component and being effective at a concentration in the range of 0.01-1000ppm.

11. The use according to claim 10, characterized in that: The stress resistance is at least one of cold resistance, drought resistance, salt resistance, high temperature resistance, waterlogging resistance, and UV damage resistance.

12. The use or growth promoter according to any one of claims 1 to 11, characterized in that: The plants include tobacco, corn, lettuce, wheat, pepper, Chinese cabbage, lettuce, bok choy, tomato, citrus, kiwi, cherry, pear, apple, cotton, cucumber and eggplant.

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