Compound regulator for relieving high-temperature drought composite stress of corn and application method of compound regulator

Abstract

The invention belongs to the technical field of agriculture, and particularly discloses a compound regulator for relieving high-temperature drought composite stress of corn and an application method of the compound regulator. The compound regulator disclosed by the invention is a compound regulator solution prepared by adding L-valine, phthalic acid and a bacillus altitudinis fungicide into water. Before sowing, corn seeds are soaked with a compound regulator solution, sowing is conducted after seed soaking, and when the seeds germinate, the germination rate is measured; the method comprises the following steps: applying a compound regulator solution into soil when three leaves or five leaves are formed after corn seedlings emerge, carrying out analytic statistics on plant dry weight, root system dry weight, plant water content or root system indexes of corn in 7-8 days after the compound regulator solution is applied, and judging the effect of the compound regulator on relieving the high-temperature drought composite stress of the corn according to statistical data. The compound regulator product has the advantages that the high-temperature drought composite stress resistance of the corn is obviously improved, the growth and development of root systems are promoted, and the compound regulator product has important significance in improving the production potential of the corn in the Huang-Huai-Hai region under the climate change background.

Description

1. Technical field:

[0001] The invention belongs to the technical field of agriculture, and particularly relates to a compound regulator for alleviating the high-temperature and drought combined stress of corn and an application method thereof. 2. Background technology:

[0002] The Huang-Huai-Hai region is the main summer corn production area in my country, and grain production has a significant impact on the whole country. Affected by global warming and monsoon climate, agricultural meteorological disasters in Henan Province are of many types, widely distributed, and occur frequently, causing serious losses to agricultural production. For example, from June to August 2014, Henan Province suffered the most severe drought since 1951, with an affected area of ​​1.8093 million hm2. 2 The total area with no harvest reached 203,800 hm2 2 Since May 2024, the rainfall in Henan Province has been more than 70% less than the multi-year average. More than half of the meteorological monitoring stations have reached the level of moderate drought or above. The scope of severe drought and extreme drought continues to expand, and these extreme weather conditions often do not occur alone, but are accompanied by each other, exacerbating the negative impact on summer corn yields.

[0003] Plant growth regulators are artificially synthesized (or natural extracted from microorganisms) chemical substances that have a regulatory effect on the growth and development of plants and have chemical properties similar to plant hormones. After crops are subjected to abiotic stress, exogenous application of regulators can effectively alleviate the damage and reduce yield and economic loss. At present, there are many reports on regulators for crop response to single stress, and mature products are available, but there are few reports on regulator products that can alleviate the combined stress of high temperature and drought. Therefore, based on the growth and development of corn in the Huanghuaihai region and the physiological and biochemical characteristics of corn when meteorological disasters occur, it is urgent to develop a compound regulator that can effectively alleviate the combined stress of high temperature and drought. 3. Summary of the invention:

[0004] The technical problem to be solved by the present invention is: in view of the current lack of a compound regulator that can effectively alleviate the high temperature and drought combined stress of corn, the present invention provides a compound regulator for alleviating the high temperature and drought combined stress of corn and an application method thereof. The compound regulator product of the present invention has the advantages of significantly improving the resistance of corn to the high temperature and drought combined stress, promoting the growth and development of the root system, and is of great significance for improving the production potential of corn in the Huanghuaihai region under the background of climate change.

[0005] In order to solve the above problems, the technical solution adopted by the present invention is:

[0006] The invention provides a compound regulator for alleviating the high-temperature and drought combined stress of corn. The compound regulator is a compound regulator solution prepared by adding L-valine, phthalic acid and a Bacillus subtilis agent BAC into water.

[0007] According to the above-mentioned compound regulator for alleviating the combined stress of high temperature and drought in corn, the concentration of L-valine in the compound regulator solution is 200-500 μM, the concentration of phthalic acid is 0.1-1 mM, and the concentration of Bacillus subtilis agent BAC is 0.1-1 g / L.

[0008] According to the above-mentioned compound regulator for alleviating the high temperature and drought combined stress of corn, the concentration of L-valine in the compound regulator solution is 300-400 μM, the concentration of phthalic acid is 0.5-1 mM, and the concentration of Bacillus subtilis agent BAC is 0.5-1 g / L.

[0009] According to the above-mentioned composite regulator for alleviating the combined stress of high temperature and drought in corn, when the L-valine, phthalic acid and Bacillus subtilis inoculant BAC are added to water for preparation, based on each liter of water, the amount of L-valine added is 0.02343-0.05857 g, the amount of phthalic acid added is 0.0166-0.166 g, and the amount of Bacillus subtilis inoculant BAC added is 0.1-1 g.

[0010] In addition, a method for applying the above-mentioned compound regulator to alleviate the high temperature and drought combined stress of corn is provided, and the application method comprises the following steps:

[0011] a. Before sowing, soak corn seeds in the compound regulator solution (to improve the germination rate of corn seeds);

[0012] b. Sowing corn seeds after soaking. When the seeds germinate, the germination rate is measured. The effect of the compound regulator on alleviating the combined stress of high temperature and drought in corn is judged by the germination rate;

[0013] c. When the corn has three to five leaves after emergence, the compound regulator solution is applied to the soil. When the compound regulator solution is applied, 20 to 30 mL of the compound regulator solution is applied to each corn plant;

[0014] At this time, the compound regulator solution is applied to improve the growth of crops and alleviate the damage to plants caused by the combined stress of high temperature and drought;

[0015] d. 7-8 days after the application of the compound regulator solution, the plant dry weight, root dry weight, plant water content and root indexes of corn were analyzed and statistically analyzed, and the effect of the compound regulator on alleviating the combined stress of high temperature and drought in corn was determined based on the statistical data.

[0016] According to the above-mentioned method of applying the compound regulator to alleviate the combined stress of high temperature and drought in corn, the soaking time in step a is 6 to 8 hours.

[0017] According to the above-mentioned method for applying the compound regulator to alleviate the high temperature and drought combined stress of corn, the compound regulator solution in step c is applied to the soil 2 to 3 times.

[0018] According to the above-mentioned application method of the compound regulator in alleviating the high temperature and drought combined stress of corn, the plant dry weight in step d is the weight of the plant after the root system is removed and dried (g); the root system dry weight is the weight of the root system plant after drying (g);

[0019] The plant water content RWC = (FW-DW) / (TW-DW)*100%;

[0020] Among them, RWC represents relative water content of leaves, FW represents fresh weight of leaves, DW represents dry weight of leaves, and TW represents regenerated weight of leaves;

[0021] The aboveground biomass of plants in each treatment was observed on the 0th day of drought and 10th day after drought to calculate the relative growth rate of plants before and after drought. The relative growth rate of plants before and after drought was calculated by dividing the difference in aboveground biomass on the 0th day of drought and 10th day after stress (g plant') by the number of days between the two samplings;

[0022] Relative growth rate = (last plant dry weight - previous plant dry weight) / (T 10d -T 0d )

[0023] The root indexes were measured by scanning the root system with Epson Scan 800F, 668403A at a resolution of 400 dpi, and the root structure was analyzed with WinRHIZOPro 2009 software after scanning.

[0024] According to the above-mentioned method of applying the compound regulator to alleviate the high temperature and drought combined stress of corn, the plant height is the average height from the ground to the top of the leaves, cm.

[0025] The positive beneficial effects of the present invention are:

[0026] 1. The compound regulator of the present invention can effectively promote the germination rate of corn seeds under the combined stress of high temperature and drought, and can also promote the relative water content of corn leaves and the growth and development of the root system at the seedling stage. Therefore, the effect of the growth and development of corn plants under the combined stress can be significantly improved.

[0027] 2. In the face of global warming, high temperature and drought have become the main challenges faced by agricultural production. The present invention alleviates the damage of corn to high temperature and drought stress by applying compound regulators exogenously, and the germination rate and seedling effect of corn are significant. Therefore, the application of compound regulators is of great significance to reducing farmers' economic losses and ensuring food security.

[0028] 3. By applying the compound regulator of the present invention, the germination rate of corn seeds can be significantly improved, the rooting is promoted to be deep, and the damage to corn plants caused by the combined stress of high temperature and drought is reduced.

[0029] 4. The compound regulator of the present invention is easy to prepare, simple to apply, has good economic benefits, and is easy to promote and use on a large scale.

[0030] In summary, the compound regulator product of the present invention can significantly improve the resistance of corn to high temperature and drought combined stress, promote root growth and development, and is of great significance for improving the production potential of corn in the Huanghuaihai region under the background of climate change. 4. Description of the drawings:

[0031] Figure 1 Schematic diagram of maize phenotypes under high temperature and drought combined stress with different concentrations of L-valine;

[0032] Figure 2 Effects of different concentrations of L-valine on the aerial parts and root system of corn under combined stress of high temperature and drought;

[0033] Figure 3 Schematic diagram of corn phenotypes with different concentrations of phthalic acid under combined stress of high temperature and drought;

[0034] Figure 4 Effects of different concentrations of phthalic acid on the aerial parts and root system of corn under combined stress of high temperature and drought;

[0035] Figure 5 Schematic diagram of corn phenotypes under different concentrations of D-fructose under combined stress of high temperature and drought;

[0036] Figure 6 Effects of different concentrations of D-fructose on the aerial parts and root system of corn under combined stress of high temperature and drought;

[0037] Figure 7 Schematic diagram of maize phenotypes under different concentrations of glutathione under combined stress of high temperature and drought;

[0038] Figure 8 Effects of different concentrations of glutathione on the aerial parts and root system of corn under combined stress of high temperature and drought;

[0039] Fig. 9 Schematic diagram of corn phenotypes with different concentrations of orotic acid under combined stress of high temperature and drought;

[0040] Fig.10 Effects of different concentrations of orotic acid on the aerial parts and root system of corn under high temperature and drought combined stress;

[0041] Fig.11 Schematic diagram of corn phenotypes under high temperature and drought combined stress with different concentrations of Bac bacteria;

[0042] Fig.12 Effects of different concentrations of Bac bacteria on the aerial parts and root system of corn under high temperature and drought combined stress;

[0043] Fig.13 Schematic diagram of corn phenotypes in different combinations under high temperature and drought combined stress;

[0044] Fig.14 Effects of different compound combinations on the aerial parts and root system of corn under high temperature and drought combined stress;

[0045] Fig.15 The effect of applying different regulating substances on corn seed germination;

[0046] Fig.16 Schematic diagram of single and compound combination maize phenotypes under high temperature and drought combined stress;

[0047] Fig.17 Effects of single and compound combinations on the aboveground parts and root system of corn under high temperature and drought combined stress.

[0048] By attaching Figure 1-12 The types and concentration ranges of regulators that can significantly alleviate the combined stress of high temperature and drought can be preliminarily screened. Figure 13-14 It can be preliminarily verified that the three-substance compound regulator is significantly higher than the two-substance compound regulator in terms of leaf relative water content, root dry weight and total root volume. Figure 15-17 It can be concluded that the compound regulator significantly promotes corn seed germination and improves germination rate, while significantly increasing corn root dry weight, total root length and number of root tips, and can effectively alleviate the damage caused by high temperature and drought combined stress. V. Specific implementation methods:

[0049] The present invention is further described below in conjunction with embodiments, but the protection scope of the technical solution of the present invention is not limited thereto.

[0050] The optimization process test of L-valine, phthalic acid and BAC bacterial agent used in the compound regulator of the present invention is as follows:

[0051] 1. Materials used: Pioneer 335 (American Pioneer Seed Company), BAC bacteria agent, L-valine

[0052] (CAS: 72-18-4), phthalic acid (CAS: 88-99-3), D-fructose (CAS: 57-48-7), orotic acid (CAS: 65-86-1), L-glutathione (CAS: 27025-41-8). The nutrient solution ingredients are: Hoagland nutrient solution (Hoagland 1.26g / L + calcium salt 0.945g / L), 20% polyethylene glycol 6000 (PEG 6000) to simulate drought stress, and a constant temperature incubator and an intelligent greenhouse to achieve high temperature stress.

[0053] 2. Hydroponic screening test methods and results:

[0054] After analyzing the metabolomics of maize rhizosphere under drought, high temperature, high temperature and drought combined (DTS) and control (Control) conditions, the metabolites significantly upregulated under high temperature and drought combined stress were L-valine, phthalic acid, D-fructose, glutathione and orotic acid. In order to further verify whether the regulator can improve the high temperature and drought resistance of maize, under indoor hydroponic test conditions, 20% PEG6000 simulated drought stress + 40±2℃ incubator simulated high temperature stress, different concentrations of regulators were applied to the maize rhizosphere exogenously under high temperature and drought combined stress, and the optimal concentration for alleviating high temperature and drought combined stress was screened by measuring biomass, plant height, leaf relative water content and root development indicators.

[0055] The results show that: Figure 1-12 It can be concluded that compared with the DTS treatment, DTS+350μM L-valine significantly increased the plant height by 9.55%, the plant dry weight by 27.74%, and the root dry weight by 28.93%; DTS+1mM phthalic acid significantly increased the plant height by 13.5%, the aboveground dry weight by 43.9%, and the total root length and total surface area of ​​the root system also increased significantly; the application of different concentrations of glutathione and orotic acid under high temperature and drought combined stress could not be effectively alleviated; DTS+1g / L Bac inoculant significantly increased the aboveground dry weight by 43.9%, the relative water content of the leaves by 21.5%, and the root dry weight, total root length, and total root volume also increased significantly. Based on the above experimental results, the present invention screened out substances that effectively alleviate the high temperature and drought combined stress, and then the present invention used a variety of substances to compound to improve the effect of the regulator experiment (see attached for details). Figure 13-14 ), the results of compounding showed that the compounding of L-valine, phthalic acid and Bac inoculant had better effect on the growth and development of corn under the combined stress of high temperature and drought than the compounding of any two of them, which was mainly reflected in the effects on plant dry weight, root dry weight and total root volume.

[0056] Embodiment 1:

[0057] The invention discloses a composite regulator solution for alleviating the high-temperature drought combined stress of corn. L-valine (0.041 g), phthalic acid (0.166 g) and Bacillus subtilis BAC (1 g) are added into 1 L of water to prepare the composite regulator solution. In the obtained composite regulator solution, the concentration of L-valine is 350 μM, the concentration of phthalic acid is 1 mM, and the concentration of Bacillus subtilis BAC is 1 g / L.

[0058] Embodiment 2:

[0059] The method for applying the compound regulator solution described in Example 1 of the present invention to alleviate the high temperature and drought combined stress of corn has the following detailed steps:

[0060] a. Before sowing, soak corn seeds in the compound regulator solution for 8 hours (to improve the germination rate of corn seeds);

[0061] b. Sowing corn seeds after soaking. When the seeds germinate, the germination rate is measured (the results are shown in 1, and the germination rate reaches 87.64%).

[0062] c. Apply the compound regulator solution to the soil three times (one day interval between two applications of the compound regulator solution) when the corn has three to five leaves after the seedlings emerge. Each time the compound regulator solution is applied, 20 mL of the compound regulator solution is applied to the soil per corn plant.

[0063] At this time, the compound regulator solution is applied to improve the growth of crops and alleviate the damage to plants caused by the combined stress of high temperature and drought;

[0064] d. Seven days after the application of the compound regulator solution, the plant dry weight, root dry weight, plant water content, and root indexes of corn were analyzed and statistically analyzed. The analysis results are detailed in Fig.17 ;Depend on Fig.17 It can be concluded that compared with DTS, the root dry weight of the compound treatment increased significantly by 40.7%, the number of root tips increased significantly by 20.2%, the plant height increased by 12.0%, the aboveground dry weight increased by 27.9%, and the relative growth rate increased by 66.7%.

[0065] In this embodiment, the DTS conditions of high temperature and drought combined stress are: field water holding capacity 45±5%, greenhouse temperature 40℃±2℃; in the comparative example, the control conditions are: field water holding capacity 80±5%, atmospheric temperature 30±2℃,

[0066] During the application of this embodiment, a comparative example was also made. The comparative example is shown in Fig.15 and Table 1.

[0067] Table 1 Effects of applying different regulating substances on the germination rate of corn seeds

[0068]

[0069] In summary, the compound regulator of the present invention can significantly improve the growth of crops, alleviate the damage of high temperature and drought combined stress to plants, improve the water use efficiency of crops and promote root growth.

Claims

1. A compound regulator for alleviating the combined stress of high temperature and drought in corn, characterized in that: The compound regulator is a compound regulator solution prepared by adding L-valine, phthalic acid and Bacillus subtilis bacteria agent BAC into water.

2. The compound regulator for alleviating the high temperature and drought combined stress of corn according to claim 1, characterized in that: The concentration of L-valine in the compound regulator solution is 200-500 μM, the concentration of phthalic acid is 0.1-1 mM, and the concentration of Bacillus subtilis inoculant BAC is 0.1-1 g / L.

3. The compound regulator for alleviating the high temperature and drought combined stress of corn according to claim 2, characterized in that: The concentration of L-valine in the compound regulator solution is 300-400 μM, the concentration of phthalic acid is 0.5-1 mM, and the concentration of Bacillus subtilis inoculant BAC is 0.5-1 g / L.

4. The compound regulator for alleviating the high temperature and drought combined stress of corn according to claim 1, characterized in that: When the L-valine, phthalic acid and Bacillus subtilis BAC are added into water for preparation, based on each liter of water, the amount of L-valine added is 0.02343-0.05857 g, the amount of phthalic acid added is 0.0166-0.166 g, and the amount of Bacillus subtilis BAC added is 0.1-1 g.

5. A method for applying the compound regulator according to claim 1 to alleviate the high temperature and drought combined stress of corn, characterized in that: The application method comprises the following steps: a. Before sowing, soak corn seeds in the compound regulator solution; b. Sowing corn seeds after soaking. When the seeds germinate, the germination rate is measured. The effect of the compound regulator on alleviating the combined stress of high temperature and drought in corn is judged by the germination rate; c. When the corn has three to five leaves after emergence, the compound regulator solution is applied to the soil. When the compound regulator solution is applied, 20 to 30 mL of the compound regulator solution is applied to each corn plant; d. 7-8 days after the application of the compound regulator solution, the plant dry weight, root dry weight, plant water content and root indexes of corn were analyzed and statistically analyzed, and the effect of the compound regulator on alleviating the combined stress of high temperature and drought in corn was determined based on the statistical data.

6. The method for applying the composite regulator according to claim 5 to alleviate the high temperature and drought combined stress of corn, characterized in that: The seed soaking time in step a is 6 to 8 hours.

7. The method for applying the composite regulator according to claim 5 to alleviate the high temperature and drought combined stress of corn, characterized in that: The compound regulator solution in step c is applied to the soil 2 to 3 times.

8. The method for applying the composite regulator according to claim 5 to alleviate the high temperature and drought combined stress of corn, characterized in that: The plant dry weight in step d is the weight of the plant after the root system is removed and dried (g); the root system dry weight is the weight of the plant after the root system is dried (g); The plant water content RWC = (FW-DW) / (TW-DW)*100%; Among them, RWC represents relative water content of leaves, FW represents fresh weight of leaves, DW represents dry weight of leaves, and TW represents regenerated weight of leaves; The root indexes were measured by scanning the root system with Epson Scan 800F, 668403A at a resolution of 400 dpi, and WinRHIZOPro 2009 software was used to analyze the root structure after scanning.

9. The method for applying the composite regulator according to claim 8 to alleviate the combined stress of high temperature and drought in corn, characterized in that: The plant height is the average height from the ground to the top of the leaves in cm.

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