Application of exogenous choline aspartate in increasing maize yield

Abstract

The present invention belongs to the technical field of plant growth promoters, and specifically relates to the application of exogenous choline aspartate in increasing the yield of maize. Choline aspartate is prepared according to the following steps: at room temperature, an aqueous solution of choline hydroxide is mixed with aspartic acid, and then shaken in a shaker for 48-72 h at a shaker speed of 180-220 r / min. After the reaction is completed, the water is removed to obtain choline aspartate. The present invention explores the application of exogenous choline aspartate as a growth promoter or synergist in increasing the yield of maize. Using the self-synthesized choline aspartate as the material, it is found that spraying this compound at the early stage of maize filling can significantly promote the increase of the grain weight per ear of maize, achieving the purpose of promoting maize growth and increasing the yield of maize.

Description

Technical Field

[0001] The present invention belongs to the technical field of plant growth promoters, and specifically relates to the application of exogenous choline aspartate in increasing the yield of maize. Background Art

[0002] Choline is a small molecule widely present in animal and plant cells, which participates in the formation of biological cell membranes and other structures, and is also an important micronutrient. Choline is non-toxic and biodegradable, and is an excellent cationic selector for synthesizing "green" compounds.

[0003] As an important food and feed crop, maize is widely planted worldwide. China is a major producer and consumer of maize. In recent years, with the development of related industries such as animal husbandry and processing industries, the demand for maize as the main feed and industrial raw material has shown a continuous growth trend. Drought and water shortage are the main limiting factors restricting maize production in China. It triggers different changes in crops through various reactions such as morphology, physiology, and biochemistry, resulting in damage to maize metabolism and physiological functions, and a decrease in yield levels. Reasonably using exogenous plant growth substances is an important means to regulate and improve the growth and development of crops and enhance stress resistance.

[0004] Currently, although various chemical regulation reagents are commonly used in maize production, such as Yuhuajin, chlormequat chloride, uniconazole (paclobutrazol), etc., there is a relatively common problem in the use of the above reagents, that is, most of the above reagents are growth-inhibiting plant growth regulators, and their action mechanisms usually include controlling the excessive growth or spindling of plants, promoting root growth and strengthening seedlings, appropriately reducing plant height, increasing stem diameter, improving lodging resistance and yield, etc. Therefore, it is more suitable for controlling the excessive growth of plants under good water and fertilizer conditions to prevent lodging, spindling, and lodging, etc., but it is not fully applicable under poor production environments, such as soil drought, infertility, etc. And the use of such compounds requires relatively high technical requirements for operators. If the concentration is too high or too low, or the application period is incorrect, etc., it will cause them to not function properly in actual use, and even play the opposite role, seriously dampening the enthusiasm of producers for use and restricting the application of the above regulators. Summary of the Invention

[0005] Aiming at the deficiencies of the above-mentioned prior art, the purpose of the present invention is to provide the application of exogenous choline aspartate in increasing the yield of maize. Considering the possible problems such as the unclear effect and relatively high technical requirements in the use of growth-inhibiting regulators in current maize production, the present invention explores the application of exogenous choline aspartate as a growth promoter or synergist in increasing the yield of maize. Using self-synthesized choline aspartate as the material, the present invention discovers that spraying this compound at the initial stage of maize grain filling can significantly promote the increase in the grain weight per ear of maize, achieving the purpose of promoting maize growth and increasing the yield of maize.

[0006] To solve the above technical problems, the present invention adopts the following technical solutions:

[0007] Application of exogenous choline aspartate in increasing maize yield, wherein the structure of the choline aspartate is shown in formula (I):

[0008]

[0009] Preferably, the choline aspartate is prepared according to the following steps:

[0010] At room temperature, an aqueous solution of choline hydroxide is mixed with aspartic acid, and then reacted on a shaker for 48 - 72 h, and the water is removed to obtain choline aspartate.

[0011] Preferably, the molar ratio of choline hydroxide to aspartic acid is 1:1.

[0012] Preferably, the mixing method is: under stirring conditions, aspartic acid is added dropwise to the aqueous solution of choline hydroxide and mixed.

[0013] Preferably, the rotation speed of the shaker is 180 - 220 r / min.

[0014] Preferably, the choline aspartate is used to prepare a maize growth promoter or synergist.

[0015] Preferably, the application method is: at the initial stage of maize filling, the maize plants are sprayed with choline aspartate, the spraying concentration is 50 - 100 mg / L, and the spraying dose is 20 - 40 L / acre.

[0016] Compared with the prior art, the beneficial effects of the present invention are:

[0017] 1. Choline aspartate ([Chl][Asp]) is a new type of choline compound synthesized with choline as the cation and aspartic acid as the anion, and there has been no relevant report on its promoting effect on crop yield before. In this study, the foliar spraying method was used to investigate for the first time the effect of adding low - concentration (50 - 100 mg / L) choline aspartate in maize cultivation. The results show that choline aspartate can effectively promote the increase of grain weight per ear and improve the yield, which provides a new technical means for the development and application of choline aspartate as a maize yield - increasing promoter.

[0018] 2. The mechanism of action of choline aspartate as a promoter or synergist is as follows: Through our research, the promoting effect of choline aspartate spraying on maize yield may have the following two aspects of action mechanisms:

[0019] (1) Choline aspartate improves the nutritional level of maize in the form of a micronutrient, promotes the accumulation of plant biomass, and thus increases the grain weight per ear and the yield;

[0020] (2) Research in this application shows that exogenous addition of choline aspartate can significantly improve the photosynthetic function of maize leaves. Therefore, it may increase the maize yield by enhancing the photosynthetic capacity.

[0021] 3. The choline aspartate synthesized in this research aims to effectively combine the physiological functions of choline and aspartate. Its mechanism of action is different from that of growth-inhibiting regulators. Instead, as a micronutrient fertilizer or physiologically active substance, it improves the biomass and yield per plant by directly enhancing the growth status of plants, thus avoiding potential problems such as poor actual usage effects and high technical requirements that may exist in growth-inhibiting regulators. Meanwhile, the synthesis method of choline aspartate is simple to operate, and the reagents used are all common and easily obtainable reagents. The synthesis and preparation costs are low. Both the raw materials and the product choline aspartate used in the synthesis process are green compounds with extremely low toxicity, and no by-products are generated during the synthesis process, featuring environmental friendliness. Therefore, this compound can provide technical support for the development and application of novel and efficient maize yield promoters. Description of the Drawings

[0022] Figure 1 Is a physical diagram of choline aspartate prepared in Example 1 of the present invention;

[0023] Figure 2 Is a hydrogen spectrum diagram of choline aspartate prepared in Example 1 of the present invention;

[0024] Figure 3 Is a physical diagram of maize planted in the experimental group and control group of the present invention. Detailed Description of the Invention

[0025] The following is a detailed description of the specific implementation manners of the present invention. However, it should be understood that the protection scope of the present invention is not limited by the specific implementation manners. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts fall within the protection scope of the present invention. The experimental methods described in each embodiment of the present invention are all conventional methods unless otherwise specified.

[0026] Example 1

[0027] The preparation method of choline aspartate includes the following steps:

[0028] Choline aspartate is synthesized using two compounds, an aqueous solution of choline hydroxide and aspartic acid. The volume ratio of choline hydroxide to water in the aqueous solution of choline hydroxide is 46:100. The main synthesis method is the neutralization method, and the specific steps are as follows:

[0029] At room temperature, choline hydroxide aqueous solution and aspartic acid are mixed in a molar ratio of 1:1. The mixing method is to gradually add them drop by drop in small amounts. Aspartic acid is added dropwise to the choline hydroxide aqueous solution, and the whole process is carried out on a magnetic stirrer. Then, it reacts in a shaker for 48 h at a shaker temperature of 18 °C and a rotation speed of 200 r / min. After the reaction is completed, water is removed at 55 °C using a rotary evaporator to obtain choline aspartate.

[0030] Example 2

[0031] A preparation method of choline aspartate, comprising the following steps:

[0032] Choline aspartate is synthesized using two compounds, choline hydroxide aqueous solution and aspartic acid. The volume ratio of choline hydroxide to water in the choline hydroxide aqueous solution is 40:100. The synthesis method is mainly the neutralization method, and the specific steps are as follows:

[0033] At room temperature, choline hydroxide aqueous solution and aspartic acid are mixed in a molar ratio of 1:1. The mixing method is to gradually add them drop by drop in small amounts. Aspartic acid is added dropwise to the choline hydroxide aqueous solution, and the whole process is carried out on a magnetic stirrer. Then, it reacts in a shaker for 72 h at a shaker temperature of 25 °C and a rotation speed of 220 r / min. After the reaction is completed, water is removed at 55 °C using a rotary evaporator to obtain choline aspartate.

[0034] Example 3

[0035] A preparation method of choline aspartate, comprising the following steps:

[0036] Choline aspartate is synthesized using two compounds, choline hydroxide aqueous solution and aspartic acid. The volume ratio of choline hydroxide to water in the choline hydroxide aqueous solution is 50:100. The synthesis method is mainly the neutralization method, and the specific steps are as follows:

[0037] At room temperature, choline hydroxide aqueous solution and aspartic acid are mixed in a molar ratio of 1:1. The mixing method is to gradually add them drop by drop in small amounts. Aspartic acid is added dropwise to the choline hydroxide aqueous solution, and the whole process is carried out on a magnetic stirrer. Then, it reacts in a shaker for 60 h at a shaker temperature of 35 °C and a rotation speed of 180 r / min. After the reaction is completed, water is removed at 55 °C using a rotary evaporator to obtain choline aspartate.

[0038] 1. Structure analysis

[0039] In Examples 1 - 3 of the present invention, choline aspartate with high purity is prepared, and the yield of the obtained choline aspartate is greater than 95%. It is a liquid at room temperature and is light yellow to light brown ( Figure 1 ). Nuclear magnetic resonance spectroscopy is used to identify the structure of the choline aspartate prepared in Example 1 ( Figure 2) It can be seen from the integral ratio of hydrogen atoms in the hydrogen spectrum that the purity of the synthesized choline aspartate is greater than 95%, verifying the correctness of the synthesized structure.

[0040] Table 1 Identification results of nuclear magnetic resonance spectroscopy of choline aspartate

[0041]

[0042] 2. Analysis of the effect of choline aspartate spraying on maize yield

[0043] (1) Research method:

[0044] This experiment was carried out for two years, from June to October 2021 and from June to October 2022 at the Caoxinzhuang Experimental Farm of Northwest A&F University, which is located in Yangling Demonstration Zone, Xianyang City, Shaanxi Province. The basic soil nutrients of the experimental field were: soil pH 8.26, organic matter 15.98 g / kg, available phosphorus 28.67 mg / kg, available potassium 170 mg / kg, total nitrogen 1.01 g / kg. The test material was the maize variety Zhengdan 958 (Beijing Denong Seed Industry).

[0045] Spraying conditions: At the early filling stage of maize, exogenous choline aspartate was used to spray maize plants (experimental group), the spraying concentration was 100 mg / L, and the spraying dose was 30 L / acre. Spraying with clear water was used as the control group (CK). The plot area was 27 m 2 , with 3 replicates for each treatment, the planting density was 4,500 plants / acre, and conventional field management was carried out. The plots were randomly arranged, and the management measures were the same. Samples were taken at the mature stage of maize, and the biomass of each part was measured by oven drying, and indexes such as ear grain weight were measured by the weighing method.

[0046] (2) Research results:

[0047] Tables 2 and 3 show the effects of exogenous choline aspartate on maize yield and biomass during the two-year maize growing seasons of 2021 - 2022. Compared with the control, in 2021, the biomass per plant of maize under the treatment of choline aspartate ([Chl][Asp]) increased by 14.8%, the ear grain weight increased by 13.3%, and the yield increased by 14%. In 2022, the biomass per plant of maize under the treatment of choline aspartate ([Chl][Asp]) increased by 15.6%, the ear grain weight increased by 15.5%, and the yield increased by 15.3%. The above results indicate that exogenous choline aspartate treatment helps to increase the ear grain weight of maize and increase the yield. At the same time, the stem biomass, leaf biomass, etc. under the choline aspartate treatment are significantly increased compared with the control. It can be seen that the yield-increasing mechanism of choline aspartate may be related to promoting the growth of plant stems, leaves, etc., increasing the biomass per plant of the plant, and then increasing the ear grain weight and yield, etc.

[0048] Table 2 Effects of exogenous choline aspartate on maize biomass from 2021 to 2022

[0049]

[0050] Note: The data in the table are presented as mean ± standard deviation (n = 3). "*" indicates a significant difference between the experimental group and the control group (p < 0.05). The same applies hereinafter.

[0051] Table 3 Effects of exogenous choline aspartate on grain weight per ear and yield of maize from 2021 to 2022

[0052]

[0053] The physical picture is as Figure 3 shown, which is consistent with the conclusions obtained from Table 2 and Table 3.

[0054] (3) Physiological mechanism analysis

[0055] To investigate the molecular mechanism of choline aspartate regulating maize growth, we used the method of adding in hydroponic nutrient solution to analyze the differential gene expression of exogenous choline aspartate ([Chl][Asp]) leaves and control (without addition) leaves. The results showed that compared with the leaves of the control (CK, without choline aspartate), adding low-concentration choline aspartate (20 mg / L) in hydroponic nutrient solution caused significant changes in the gene expression profiles related to photosynthesis and chlorophyll synthesis in maize leaves.

[0056] The research results are shown in Table 4 and Table 5. In the chlorophyll metabolism pathway, compared with the control, a total of 15 genes related to chlorophyll synthesis were significantly up-regulated under choline aspartate treatment, indicating that choline aspartate significantly promoted the chlorophyll synthesis metabolism pathway (Table 4). In the photosynthesis pathway, compared with the control, 15 out of 17 differential genes were up-regulated and only 2 were down-regulated under choline aspartate treatment. Most of the up-regulated genes were those encoding photosystem reaction center proteins, indicating that choline aspartate had an obvious promoting effect on the expression of genes related to photosynthesis (Table 5). Based on the above analysis, the mechanism of exogenous choline on regulating maize growth may be related to its promoting effect on photosynthesis and chlorophyll synthesis pathways.

[0057] Table 4 Differentially expressed genes in the chlorophyll metabolism pathway of maize leaves under choline aspartate treatment compared with the control

[0058]

[0059] Table 5 Differentially expressed genes in the photosynthesis pathway of maize leaves under choline aspartate treatment compared with the control

[0060]

[0061] Those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalent technologies, the present invention also intends to include these modifications and variations.

Claims

1. Use of exogenous choline aspartate in increasing maize yield, characterized in that, The structure of the choline aspartate is shown in formula (I): The application method is as follows: at the initial stage of corn filling, spray the corn plants with choline aspartate, the spraying concentration is 50-100 mg / L, and the spraying dose is 20-40 L / mu.

2. Use of exogenous choline aspartate according to claim 1 in increasing maize yield, characterized in that, The choline aspartate is prepared according to the following steps: At room temperature, mix an aqueous solution of choline hydroxide with aspartic acid, and then react on a shaker for 48-72 h, remove the water to obtain choline aspartate.

3. Use of exogenous choline aspartate according to claim 2 in increasing maize yield, characterized in that, The molar ratio of choline hydroxide to aspartic acid is 1:

1.

4. Use of exogenous choline aspartate according to claim 2 in increasing the yield of maize, characterized in that The mixing method is: under stirring conditions, drop aspartic acid into the aqueous solution of choline hydroxide and mix.

5. The use of exogenous choline aspartate according to claim 2 in increasing the yield of maize, characterized in that, The rotation speed of the shaker is 180-220 r / min.

6. The use of exogenous choline aspartate in increasing the yield of maize according to claim 1, characterized in that, The choline aspartate is used to prepare a corn growth promoter or synergist.

Images