An anti-transpiration agent for reducing plant transpiration and preparation method thereof

Abstract

The present invention relates to an anti-transpiration agent for reducing plant transpiration and a preparation method thereof, which includes an agent A and an agent B, wherein the agent A is composed of a water-soluble chitosan solution, a metal organic framework MIL-125 (Ti) and a phosphate buffer, and the agent B is composed of glycerol, ferric chloride and water. In sunny weather, the agent A is first sprayed on the plant leaf surface using a sprayer, and 1.5 to 2 hours after the spraying is completed, the agent B is sprayed on the plant leaf surface using a sprayer, and after the leaf surface is dried, a layer of anti-transpiration agent is attached to the leaf surface. The anti-transpiration agent for reducing plant transpiration of the present invention is sprayed on the leaves of the plant, which can significantly reduce the plant transpiration, and has a significant inhibitory effect on the transpiration rate of the plant leaves. At the same time, the leaf surface is less damaged and is not prone to poisoning symptoms. The anti-transpiration effect is more lasting, and after a single use for 9 days, there is still a certain anti-transpiration effect. The anti-transpiration agent of the present invention has good stability after film formation and good resistance to rainwater impact.

Description

Technical Field

[0001] The invention relates to an anti-transpiration agent for reducing plant transpiration and a preparation method thereof, belonging to the technical field of anti-transpiration agents. Background Art

[0002] Anti-transpiration agents, also known as transpiration inhibitors, have the following mechanism of action: after being evenly sprayed on plant leaves, a protective film is formed on the leaf surface, which closes some stomata and slows down metabolism. The unique mesh structure can ensure the normal respiration and reduce water evaporation, thereby increasing the survival rate of trees. It is mainly divided into two categories:

[0003] ①. Film-type anti-transpiration agents: paraffin, wax oil emulsion, high carbon alcohol, silicone, polyethylene, latex and resin, etc. These compounds can form a thin film on the surface of leaves or fruits to block pores and cover the cuticle, so as to prevent transpiration and water loss or keep fruits fresh.

[0004] ② Metabolic anti-transpiration agents: succinic acid, phenylmercuric acetate, hydroxysulfonic acid, chloranil, atrazine, sodium azide, etc. These compounds can cause the stomata of plants to close, thereby achieving the purpose of reducing transpiration.

[0005] Taking the film-type anti-transpiration agent as an example, if all the stomata are closed, it will form a completely airtight or slightly airtight "net plug". Although the stomata can be closed, for example, the transpiration loss can be reduced by more than 90%, but it also reduces photosynthesis, which can easily lead to metabolic obstruction, toxic symptoms, and plant death. Therefore, the general film-type anti-transpiration agent tries to reduce part of the transpiration. It is not that the more the transpiration is reduced, the better, but it should be continued for as long as possible, while not harming the stomata of the leaves. For example, existing wax oil emulsion anti-transpiration agents are generally sprayed once every 5-7 days and used continuously for 2-3 times; the reason is that the anti-transpiration effect is very weak 3-4 days after its application, and a second spraying is required; but before the second spraying, it is usually necessary to wait for 2-3 days for the leaves to clean themselves to avoid large-scale irreversible damage to the stomata on the leaves; generally, it can only be used continuously for 2-3 times, otherwise it is easy to cause large-scale irreversible damage to the stomata on the leaves; generally, it is also necessary to avoid use on rainy days. Usually, if it rains within 6 hours of spraying, a second spraying is required.

[0006] Based on this, the present invention is proposed. Summary of the invention

[0007] In view of the shortcomings of the prior art, the present invention provides an anti-transpiration agent for reducing plant transpiration and a preparation method thereof. The specific technical scheme is as follows:

[0008] In a first aspect, an anti-transpiration agent for reducing plant transpiration includes agent A and agent B, wherein agent A is composed of a water-soluble chitosan solution, a metal organic framework MIL-125 (Ti) and a phosphate buffer, and agent B is composed of glycerol, ferric chloride and water.

[0009] As a further improvement, the agent A is composed of 1000 parts by mass of a water-soluble chitosan solution, 1 to 1.1 parts by mass of a metal organic framework MIL-125 (Ti) and 5 to 10 parts by mass of a phosphate buffer.

[0010] As a further improvement, the mass fraction of the water-soluble chitosan solution is 0.5%, the phosphate buffer is composed of sodium dihydrogen phosphate and disodium hydrogen phosphate, the concentration of phosphate in the phosphate buffer is 0.2 mol / L, and the pH is 7-7.5.

[0011] As a further improvement, the agent B is composed of 3 parts by mass of glycerol and 100 parts by mass of ferric chloride solution, and the mass fraction of the ferric chloride solution is 0.1-0.12%.

[0012] In the second aspect, the preparation method of the anti-transpiration agent for reducing plant transpiration is as follows: on a sunny day, agent A is first sprayed on the plant leaves using a sprayer, and 1.5 to 2 hours after the spraying, agent B is sprayed on the plant leaves using a sprayer. After the leaf surface is dry, a layer of anti-transpiration agent is attached to the leaf surface.

[0013] A further improvement is that the temperature on a sunny day should not be lower than 25℃.

[0014] A further improvement is that when it is necessary to continue to suppress the transpiration of the plants, it is necessary to spray the anti-transpiration agent that reduces the transpiration of the plants. When spraying again, only agent A needs to be sprayed, and there is no need to spray agent B again.

[0015] Beneficial effects of the present invention:

[0016] 1. The anti-transpiration agent for reducing plant transpiration of the present invention is sprayed on the leaves of plants, which can significantly reduce plant transpiration and has a significant inhibitory effect on the transpiration rate of plant leaves. At the same time, it causes little damage to the leaf surface and is not prone to toxic symptoms.

[0017] 2. The anti-transpiration effect is more lasting. After 9 days of single use, it still has a certain anti-transpiration effect.

[0018] 3. The anti-transpiration agent of the present invention has good stability and good resistance to rain impact after film formation. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 This is a photo of a leaf of a sample that was not sprayed with an anti-transpirant;

[0020] Figure 2 This is a photo of the sample leaves 2.5 hours after spraying the anti-transpiration agent described in Example 1. DETAILED DESCRIPTION

[0021] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0022] Example 1

[0023] The anti-transpiration agent includes agent A and agent B.

[0024] The agent A is composed of 1000g of water-soluble chitosan solution, 1g of metal organic framework MIL-125 (Ti) and 5g of phosphate buffer. The mass fraction of the water-soluble chitosan solution is 0.5%, the phosphate buffer is composed of sodium dihydrogen phosphate and disodium hydrogen phosphate, the concentration of phosphate in the phosphate buffer is 0.2mol / L, and the pH is 7-7.5.

[0025] The agent B is composed of 30g of glycerol and 1000g of ferric chloride solution, and the mass fraction of the ferric chloride solution is 0.1%.

[0026] In sunny weather (temperature not lower than 25℃), first spray Agent A on the plant leaves with a sprayer. 1.5 hours after the spraying, spray Agent B on the plant leaves with a sprayer. After the leaves are dry, a layer of mesh protective film (observed under a microscope) of the anti-transpiration agent will be attached to the leaves.

[0027] Example 2

[0028] The anti-transpiration agent includes agent A and agent B.

[0029] The agent A is composed of 1000g of water-soluble chitosan solution, 1g of metal organic framework MIL-125 (Ti) and 8g of phosphate buffer. The mass fraction of the water-soluble chitosan solution is 0.5%, the phosphate buffer is composed of sodium dihydrogen phosphate and disodium hydrogen phosphate, the concentration of phosphate in the phosphate buffer is 0.2mol / L, and the pH is 7-7.5.

[0030] The agent B is composed of 30g of glycerol and 1000g of ferric chloride solution, and the mass fraction of the ferric chloride solution is 0.11%.

[0031] In sunny weather (temperature not lower than 25℃), first spray Agent A on the plant leaves with a sprayer. 1.5 hours after the spraying, spray Agent B on the plant leaves with a sprayer. After the leaves are dry, a layer of anti-transpiration agent with a mesh protective film will be attached to the leaves.

[0032] Example 3

[0033] The anti-transpiration agent includes agent A and agent B.

[0034] The agent A is composed of 1000g of water-soluble chitosan solution, 1.1g of metal organic framework MIL-125 (Ti) and 10g of phosphate buffer. The mass fraction of the water-soluble chitosan solution is 0.5%, the phosphate buffer is composed of sodium dihydrogen phosphate and disodium hydrogen phosphate, the concentration of phosphate in the phosphate buffer is 0.2mol / L, and the pH is 7-7.5.

[0035] The agent B is composed of 30g of glycerol and 1000g of ferric chloride solution, and the mass fraction of the ferric chloride solution is 0.12%.

[0036] In sunny weather (temperature not lower than 25℃), first spray agent A on the plant leaves with a sprayer. 2 hours after the spraying, spray agent B on the plant leaves with a sprayer. After the leaves are dry, a layer of anti-transpiration agent with a mesh protective film will be attached to the leaves.

[0037] Comparative Example 1

[0038] In this example, the anti-transpiration agent includes agent A and agent B. The agent A is a water-soluble chitosan solution with a mass fraction of 1%, and the agent B is glycerol.

[0039] Comparative Example 2

[0040] In this example, the anti-transpiration agent is a water-soluble chitosan solution with a mass fraction of 1%.

[0041] Comparative Example 3

[0042] In this example, the anti-transpiration agent is agent A.

[0043] Comparative Example 4

[0044] In this example, the anti-transpiration agent is agent B.

[0045] Comparative Example 5

[0046] In this example, the anti-transpiration agent is a wax oil emulsion anti-transpiration agent purchased from Laoengerun Garden Management Department in Huiji District, Zhengzhou City.

[0047] Comparative Example 6

[0048] In this example, the metal organic framework MIL-125 (Ti) in the agent A is replaced by the metal organic framework ZIF-8, and the rest are the same.

[0049] Comparative Example 7

[0050] In this example, the ferric chloride solution in the agent B is replaced by ferrous chloride solution, and the rest are the same.

[0051] 《Test for Characterization of Anti-transpiration Effect》

[0052] Group 1: Select leaves with similar stomata opening on the same green radish (100 stomata were randomly observed under a microscope, and the number of open stomata was between 75 and 80). The number of leaves was 10, and these 10 leaves were sample leaves. Mark them well. Wipe the sample leaves with a moist non-woven cloth and wait for the surface of the sample leaves to dry. Select a sunny day with a temperature of 25-27℃, and use a photosynthesis meter (purchased from Shanghai Jiya International Trading Co., Ltd.) to measure the initial transpiration rate Tr of the leaves at 12 noon. 0 On the second day, the temperature was also 25-27℃ on a sunny day. At 10 a.m., the prepared anti-transpiration agent A was sprayed on the plant leaves with a sprayer. 1.5 hours after the spraying, the agent B was sprayed on the plant leaves with a sprayer. After 30 minutes, the transpiration rate Tr of the leaves was measured. 1 Tr 1 It refers to the transpiration rate one day after spraying the anti-transpiration agent. After that, select a sunny day with a temperature of 25-27℃ and measure the transpiration rate of the leaves at 12 noon. n ,Tr n It refers to the transpiration rate n days after spraying the anti-transpiration agent (n≥1). The transpiration rate is obtained by taking the average value of multiple measurements.

[0053] Note: In case of rainy weather, simulate light in a plastic shed and greenhouse.

[0054] x n =(Tr 0 -Tr n ) / Tr 0 ;x 1 Refers to the change in transpiration rate one day after spraying the anti-transpiration agent, x n It refers to the change in transpiration rate after spraying the anti-transpiration agent n days later; if x n ≤0, indicating that the anti-transpiration agent has no anti-transpiration effect; if 1>x n >0,x n The larger the value is, the better the anti-transpiration effect of the anti-transpiration agent is; n The closer it is to 1, or even equal to 1, it means that all the stomata of the leaves are blocked. This situation should be avoided, otherwise the leaves will not be able to breathe, and they will easily wilt or even die.

[0055] The results of the tests of Examples 1 to 3 and Comparative Examples 1 to 5 according to Group 1 are shown in Table 1:

[0056] Table 1

[0057]

[0058] As shown in Table 1, the anti-transpiration agent of the present invention can significantly reduce plant transpiration and has a significant inhibitory effect on the transpiration rate of plant leaves; the anti-transpiration agent of the present invention has a more lasting effect, because a mesh protective film is formed on the surface of the leaves, and the stability of the mesh protective film is high. On the 9th day, x n In the present invention, whether the A agent, B agent or water-soluble chitosan solution is used alone, or the water-soluble chitosan solution is used in combination with glycerol, it is easy to cause the transpiration water loss to be reduced by more than 90%, which is easy to cause the leaf surface metabolism to be blocked and the toxic symptoms to appear.

[0059] In the present invention, after the combination of agent A and agent B, chitosan begins to form a film under the action of glycerol. The metal organic framework MIL-125 (Ti) is a crystalline porous material with a periodic network structure. The metal organic framework MIL-125 (Ti) is used as the nucleating body, and trivalent iron ions and phosphate ions are gathered and combined in large quantities at the metal organic framework MIL-125 (Ti), so that the film can be formed quickly. After the water is completely evaporated, it can be solidified to form a porous mesh protective film.

[0060] In the first film-forming and curing process, glycerol and trivalent iron ions are needed. In the subsequent secondary film-forming and curing process, glycerol and trivalent iron ions are no longer needed, because the residual film itself is a three-dimensional porous mesh material of organic-inorganic hybridization. When the water-soluble chitosan solution is used for secondary film formation with the metal organic framework MIL-125 (Ti) and the residual film as the nucleating body, they will also combine well with each other; compared with adding glycerol to speed up film formation, the secondary film formation does not need to add agent B, the film formation time will be extended by more than double, and the film formation efficiency is low. Therefore, when supplementing the anti-transpiration agent for the second and third time, it is recommended to spray agent A at night.

[0061] Group 2, secondary film formation test

[0062] After the film formation according to Group 1, the green radish was placed outdoors for 10 days, and then the sample leaves were sprayed with agent A (Example 1, referred to as agent A group), anti-transpiration agent (Example 1, agent A and agent B were used together, referred to as AB combination group), wax oil emulsion anti-transpiration agent (Comparative Example 5), and then Tr 1 Tr n; After n+2 days, soak the leaves in clean water for 3 hours, shake the leaves on a shaker to accelerate cleaning, wipe the moisture on the leaf surface with absorbent paper after cleaning, and randomly observe 100 stomata under a microscope to see whether there is dark tissue or ulcerated tissue around the stomata. If the area where the dark tissue or ulcerated tissue is located accounts for more than 50%, the stoma is identified as a damaged stoma; count the number of damaged stomata, and the stomatal damage rate y=total number of damaged stomata / 100; measure multiple samples multiple times and take the average.

[0063] The results of the test of Example 1 and Comparative Example 5 according to Group 2 are shown in Table 2:

[0064] Table 2

[0065]

[0066] It can be seen from Table 2 that when the anti-transpiration agent of the present invention is sprayed again (such as the second spraying, the third spraying or the fourth spraying), only agent A needs to be sprayed again, and there is no need to spray agent B again; when the anti-transpiration agent is sprayed again, if agent A and agent B are used together, although the anti-transpiration effect can be slightly improved, the mesh protective film on the leaf surface can easily cause stomata damage on the leaf surface after the second curing; therefore, when the film is formed for the second, third or fourth time, agent B cannot be added, and agent A should be sprayed at night.

[0067] If the wax oil emulsion anti-transpiration agent used in Comparative Example 5 is sprayed three times, the stomatal damage rate y will reach 16.3%; therefore, the wax oil emulsion anti-transpiration agent is usually only used continuously for 2-3 times.

[0068] The anti-transpiration agent of the present invention can be used continuously for 4 times, and the duration of a single use can reach 7-9 days; after being used continuously for 4 times, the stomatal damage rate y does not exceed 18%.

[0069] Group 3, Rain resistance test

[0070] In Group 1, in Tr 1 After the measurement, the leaves were placed 3 cm below the tap, with a water flow rate of 0.6 L / min, and the leaves were continuously rinsed for 1 hour. After the rinse, the leaves were wiped dry with absorbent paper, and the transpiration rate Tr of the leaves was measured at the same time on the next day. 2b ; z = (Tr 2b -Tr 1 ) / Tr 1 The larger the z value is, the less the mesh protective film on the leaves is retained under the impact of the faucet water flow, and the worse the inhibitory effect on transpiration is.

[0071] In Group 3, the anti-transpiration agents used were from Example 1 and Comparative Examples 5 to 7. The results are shown in Table 3:

[0072] Table 3

[0073]

[0074] It can be seen from Table 3 that the anti-transpiration agent of the present invention has good stability after film formation; according to multiple tests, it is not necessary to spray again in a short period of time (no more than 2 hours) on a light rainy day.

[0075] In the above embodiment, the metal organic framework MIL-125 (Ti) was purchased from Suzhou Beike Nanotechnology Co., Ltd., CAS No.: 1193372-03-0; molecular formula: C 48 H 4 O 36 Ti 8 Metal organic framework ZIF-8 was purchased from Xi'an Qiyue Biotechnology Co., Ltd., CAS number: 59061-53-9.

[0076] The water-soluble chitosan solution is prepared by dissolving water-soluble chitosan purchased from Hubei Huada Fine Chemical Co., Ltd. in water.

[0077] Figure 1 This is a photo of a sample leaf before spraying with anti-transpiration agent. Figure 2 is a photograph of the sample leaves 2.5 hours after the anti-transpiration agent described in Example 1 was sprayed on the sample leaves; Figure 2 The surface of the middle blade is not very smooth, this is because there is a mesh protective film on the blade, which reduces the glossiness.

[0078] The A agent needs to be shaken vigorously for about 1 minute before use.

[0079] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. An anti-transpiration agent for reducing plant transpiration, characterized in that: The invention comprises an agent A and an agent B, wherein the agent A is composed of a water-soluble chitosan solution, a metal organic framework MIL-125 (Ti) and a phosphate buffer, and the agent B is composed of glycerol, ferric chloride and water; The method for preparing the anti-transpiration agent for reducing plant transpiration comprises the following steps: On a sunny day, first spray Agent A on the plant leaves with a sprayer, and then spray Agent B on the plant leaves with a sprayer 1.5 to 2 hours after the spraying. After the leaves are dry, a layer of anti-transpiration agent will be attached to the leaves. When the anti-transpiration agent for reducing plant transpiration is sprayed again, only agent A needs to be sprayed again, and agent B does not need to be sprayed again.

2. The anti-transpiration agent for reducing plant transpiration according to claim 1, characterized in that: The agent A is composed of 1000 parts by mass of a water-soluble chitosan solution, 1 to 1.1 parts by mass of a metal organic framework MIL-125 (Ti) and 5 to 10 parts by mass of a phosphate buffer.

3. The anti-transpiration agent for reducing plant transpiration according to claim 2, characterized in that: The mass fraction of the water-soluble chitosan solution is 0.5%, the phosphate buffer is composed of sodium dihydrogen phosphate and disodium hydrogen phosphate, the concentration of phosphate in the phosphate buffer is 0.2 mol / L, and the pH is 7-7.

5.

4. The anti-transpiration agent for reducing plant transpiration according to claim 1, characterized in that: The agent B is composed of 3 parts by mass of glycerol and 100 parts by mass of ferric chloride solution, and the mass fraction of the ferric chloride solution is 0.1-0.12%.

5. The anti-transpiration agent for reducing plant transpiration according to claim 1, characterized in that: The temperature on a sunny day should not be lower than 25℃.

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