Application of disaccharides in enhancing cold resistance of crops

Abstract

The present invention discloses the application of disaccharides in enhancing the cold resistance of crops. The present invention provides the application of disaccharides in improving the cold resistance of crops, wherein the disaccharide is sucrose. The inventors of the present invention found that after the sucrose rhizosphere irrigation treatment of corn, soybean, rape, broccoli and Chinese cabbage seedlings, the wilting, yellowing and curling of the crop seedlings caused by low temperature stress were significantly alleviated, and the aboveground biomass of the crops increased significantly. Pretreatment with sucrose solution can significantly reduce the degree of leaf membrane lipid peroxidation and electrolyte exudation rate of crops, significantly improve the light energy absorption, transmission and utilization of crops, increase photochemical efficiency and chlorophyll synthesis. Therefore, sucrose can be used for the prevention and control of low temperature and cold damage in the seedling stage of corn, soybean, rape, broccoli and Chinese cabbage, enhance the cold resistance of grain and vegetable crops, and sucrose is widely available, easy to obtain, green and ecological, in line with the goal of developing green and high-quality agriculture, and cold resistance regulation technology is simple and easy to implement.

Description

Technical Field

[0001] The invention belongs to the technical field of agricultural planting, and particularly relates to the application of disaccharides in enhancing the cold resistance of crops. Background Art

[0002] Corn and soybean are the staple crops in my country. Corn is a thermophilic crop native to the tropics, and the ideal germination and emergence temperature is 30~32℃. Low temperatures during the seedling and growth stages can easily cause chilling damage to corn. If chilling damage is encountered during the sowing to emergence period, there will be difficulties in germination, late emergence, low emergence rate, weak seedlings, thin seedlings, and leaf curling. If chilling damage is encountered during the silking to maturity period, the leaves will turn purple, the grains will develop slowly, maturity will be late, and the yield will be reduced. Soybeans are thermophilic crops, and the minimum temperature for seed germination is 10℃, and the suitable temperature for growth is 20~30℃. Temperatures below 5℃ can cause chilling damage to soybeans, with problems such as leaf shrinkage, slow growth, reduced flowering, and easy lodging, resulting in unstable soybean yields.

[0003] Chinese cabbage is an important vegetable crop in northern my country. Chinese cabbage is a vegetable with relatively strong cold resistance, but when the temperature is too low during the seedling stage or when the temperature drops sharply in the late stage of cabbage heading, Chinese cabbage will also suffer from chilling damage. When the temperature is below 10℃, Chinese cabbage grows slowly, and when the temperature is below 5℃, the growth of Chinese cabbage stops. Low temperature chilling damage causes Chinese cabbage to be loose, taste dry, and prone to diseases and pests. When there is a cold wave and a sudden drop in temperature, Chinese cabbage will suffer from frost damage and it is difficult to recover. Rapeseed is an important oil crop in my country and is widely planted throughout the country. At present, most of the rapeseed varieties planted in my country need to overwinter. Low temperature chilling damage mainly occurs during the wintering period or the cold wave in early spring. Low temperature will cause the growth of rapeseed to deteriorate and the plants to be weak. Broccoli is a semi-cold-resistant vegetable. Its optimum growth temperature is 20~25℃. When the temperature is low during the seedling stage, its leaves turn white or become thin paper-like. Low temperature will also affect the differentiation of flower buds, causing broccoli to bolt and disease, affecting commercial properties.

[0004] However, in actual crop production, most of the time, cold-resistant agents are not used, resulting in severe cold damage at the seedling stage, often with more than half of the seedlings dying, and then replanting. Even if some farmers use cold-resistant agents, the quality of cold-resistant agents on the market is uneven, and there is no special cold-resistant agent for crops such as corn, soybeans, cabbage, rapeseed and broccoli.

[0005] In view of this, the present invention is proposed. Summary of the invention

[0006] The purpose of the present invention is to provide the application of disaccharide in enhancing the cold resistance of crops, so as to solve the problem of low temperature and chilling injury of main grain and vegetable crops in seedling stage and the problem of low effect and high price of cold resistance agent.

[0007] To achieve the above object, the present invention provides the following technical solutions:

[0008] In a first aspect, the present invention provides the use of a disaccharide in improving the cold resistance of crops, wherein the disaccharide is sucrose.

[0009] In the present invention, disaccharide is a carbohydrate compound composed of two monosaccharide molecules. Sucrose is a kind of disaccharide, which is formed by the condensation and dehydration of the hemiacetal hydroxyl group of one molecule of glucose and the hemiacetal hydroxyl group of one molecule of fructose, and is extracted from sugar crops such as sugar cane or sugar beet. Sucrose is the main product of photosynthesis and is widely distributed in plants. Sucrose is a natural organic matter and the main form of plant material transportation. Carbohydrates composed of sucrose are the key to determining crop yields. Sucrose is a carbon source and energy source for plants. It is not only a nutrient, but also has special physiological regulation functions.

[0010] The present invention has found through experiments that sucrose can be applied to crops at the seedling stage to improve the cold resistance of crops and solve the problem of low temperature and chilling damage at the seedling stage; at the same time, compared with brown sugar in a polysaccharide mixture, sucrose has the advantages of stronger effect and lower application amount.

[0011] In the present invention, the crops are agricultural crops; specifically, they can be food crops, cash crops and vegetable crops; for example, corn, soybeans, rapeseed, broccoli and Chinese cabbage.

[0012] In the present invention, the crop is a seedling crop, specifically a plant that has grown to 3 to 4 true leaves.

[0013] The application is specifically: applying an aqueous solution containing sucrose to the rhizosphere of crops, wherein the concentration of sucrose applied is 0.5 g / L to 3.3 g / L, preferably 0.5 g / L to 2 g / L.

[0014] According to some specific embodiments of the present invention, the optimal application concentration of sucrose is 0.5 g / L.

[0015] In a second aspect, the present invention provides a cold-resistant preparation for improving the cold resistance of crops, wherein the active ingredient includes disaccharide; the disaccharide is sucrose.

[0016] The cold-resistant preparation is an aqueous solution; the concentration of sucrose in the aqueous solution is 0.5g / L~3.3g / L, preferably 0.5g / L~2g / L.

[0017] According to some specific embodiments of the present invention, the optimal application concentration of sucrose is 0.5 g / L.

[0018] The inventors of the present invention found in their research on the cold resistance of crops that the use of 0.5g / L to 3.3g / L sucrose to treat broccoli, Chinese cabbage, rapeseed, corn and soybean seedlings can effectively alleviate the damage to plant leaf cells caused by low temperature stress and improve crop leaf photosynthesis. These results show that rhizosphere application of sucrose at an appropriate concentration can significantly enhance the cold resistance of major grain and vegetable crops.

[0019] In the present invention, the crops are agricultural crops; specifically, they can be food crops, cash crops and vegetable crops; for example, corn, soybeans, rapeseed, broccoli and Chinese cabbage.

[0020] In the present invention, the crop is a seedling crop, specifically a plant that has grown to 3 to 4 true leaves.

[0021] In a third aspect, the present invention provides a method for improving the cold resistance of crops, comprising: using an aqueous solution containing disaccharides to perform root irrigating on the crops; the disaccharide is sucrose.

[0022] In the present invention, the concentration of sucrose in the aqueous solution is 0.5 g / L to 3.3 g / L, preferably 0.5 g / L to 2 g / L.

[0023] According to some specific embodiments of the present invention, the optimal application concentration of sucrose is 0.5 g / L.

[0024] In the present invention, the rhizosphere irrigation is performed according to the following operation: 2-6 days, preferably 3 days, before the start of low temperature stress, the crops are subjected to a one-time rhizosphere irrigation; the volume of the irrigation solution per crop is 50-100 mL, preferably 80 mL.

[0025] The present invention has found through experiments that using an appropriate concentration of sucrose aqueous solution for rhizosphere irrigation of crops can effectively alleviate plant leaf cell damage caused by low temperature stress and improve crop leaf photosynthesis. These results show that rhizosphere application of sucrose at an appropriate concentration can significantly enhance the cold resistance of major grain and vegetable crops.

[0026] In the present invention, the crops are agricultural crops; specifically, they can be food crops, cash crops and vegetable crops; for example, corn, soybeans, rapeseed, broccoli and Chinese cabbage.

[0027] In the present invention, the crop is a seedling crop, specifically a plant that has grown to 3 to 4 true leaves.

[0028] Compared with the prior art, the present invention has the following beneficial effects:

[0029] 1. The present invention discovers for the first time that disaccharides can be used to protect grain and vegetable crops from low temperature damage, enhance the cold resistance of crops, and fill the gap in crop cold-resistant agent products.

[0030] 2. Compared with brown sugar, disaccharide sucrose is more effective in protecting crops from low temperature and chilling damage and requires a lower application amount.

[0031] 3. Sucrose has a wide range of sources, the raw materials are easy to obtain, the cold-resistant operation is simple and convenient, it is green and environmentally friendly, and it is in line with the goal of developing green and high-quality agriculture. The cold-resistant control technology is simple and easy to implement. DETAILED DESCRIPTION

[0032] The present invention will be further described below in conjunction with specific embodiments, but the present invention is not limited to the following embodiments.

[0033] The experimental methods used in the following examples are conventional methods unless otherwise specified. The reagents, materials, instruments, etc. used in the following examples are all commercially available unless otherwise specified.

[0034] In the following examples, the sucrose used was purchased from Langfang Qianyao Technology Co., Ltd.; the broccoli was Bilu 68, the Chinese cabbage was Beijing Xinhao 3, the rapeseed was Chunyou 5, and the corn was Nongke Nuo 336, which was a variety developed by the Vegetable Institute and Corn Institute of Beijing Academy of Agricultural and Forestry Sciences. The soybean was Zhonghuang 35, which was a variety developed by the Institute of Crop Sciences of the Chinese Academy of Agricultural Sciences.

[0035] The present invention is described in detail below with reference to the attached tables and specific embodiments.

[0036] Example 1

[0037] The preparation for improving the cold resistance of crops in this embodiment is a sucrose solution with a concentration of 0.5 g / L.

[0038] The preparation method is as follows: weigh 0.5 g of sucrose and dissolve it in 1 L of distilled water.

[0039] The method of using the preparation for improving crop cold resistance in this embodiment is as follows: 3 days before low temperature stress, 80 ml of the preparation is applied once to the root zone of the crop seedlings that have grown to 3 to 4 true leaves.

[0040] Example 2

[0041] The preparation for improving the cold resistance of crops in this embodiment is a sucrose solution with a concentration of 1 g / L.

[0042] The preparation method is as follows: weigh 1g of sucrose and dissolve it in 1L of distilled water.

[0043] The method of using the preparation for improving the cold resistance of crops in this embodiment is the same as that in Example 1.

[0044] Example 3

[0045] The preparation for improving the cold resistance of crops in this embodiment is a sucrose solution with a concentration of 3.3 g / L.

[0046] The preparation method is as follows: weigh 3.3 g of sucrose and dissolve it in 1 L of distilled water.

[0047] The method of using the preparation for improving the cold resistance of crops in this embodiment is the same as that in Example 1.

[0048] Experimental example: Effects of sucrose on physiological and biochemical parameters related to low temperature tolerance of crops

[0049] 1. Experimental Methods

[0050] The specific steps of the crop low temperature resistance experiment are as follows:

[0051] 1. The crops were placed in a light incubator (DGX-260E) (light intensity 400 µmol / m 2 / s, 12 h light / 12 h dark, normal temperature control day and night temperature 25°C / 18°C, low temperature stress day and night temperature 15°C / 5°C), broccoli, Chinese cabbage, rapeseed, corn and soybean were planted in the substrate cultivation method. After the plants grew to 3-4 true leaves, plants with the same size and growth were selected for experimental treatment.

[0052] 2. Three days before low temperature treatment, 0.5, 1 and 3.3 g / L sucrose aqueous solutions were used for rhizosphere irrigation of broccoli, and 0.5 g / L sucrose aqueous solution was used for rhizosphere irrigation of broccoli / cabbage / rapeseed / corn / soybean seedlings. The control group was treated with rhizosphere irrigation of distilled water, with 80 mL per plant applied at a time.

[0053] 3. Early in the morning of the third day, set the light incubator to low temperature stress treatment for 3 days.

[0054] 4. Observe the growth of crop plants in each group, and analyze and test the physiological and biochemical indicators closely related to low temperature tolerance.

[0055] 2. Index detection

[0056] 1. Broccoli aboveground fresh weight and leaf SPAD value

[0057] The effects of 0.5~3.3g / L sucrose solution on the growth of broccoli under low temperature stress (5℃) are shown in the following table.

[0058] Table 1 Effects of sucrose on aboveground fresh weight and SPAD value of broccoli seedlings

[0059]

[0060] The results in Table 1 show that rhizosphere irrigation with 0.5-3.3 g / L sucrose solution significantly increased the aboveground fresh weight of broccoli. SPAD values ​​of broccoli leaves were measured using a SPAD502 chlorophyll meter, and it was found that rhizosphere irrigation with 0.5-3.3 g / L sucrose solution significantly increased the SPAD values ​​of broccoli leaves.

[0061] At the same time, brown sugar was used as a parallel control test, and the results were as follows:

[0062] Table 2 Comparison of the effects of two preparations on the aboveground fresh weight of broccoli seedlings

[0063]

[0064] The results in Table 2 show that the aboveground fresh weight of broccoli seedlings pretreated with sucrose solution at a concentration of 0.5 g / L is higher than that of the same concentration of brown sugar solution, and is close to that of broccoli seedlings pretreated with brown sugar solution at a concentration of 1 g / L, indicating that when the two preparations are applied exogenously to achieve similar growth improvement effects, the amount of sucrose is only 50% of that of brown sugar. The cost of food-grade brown sugar is about 6,500 yuan / ton, and the cost of sucrose is about 4,000 yuan / half ton. When the same cold-resistant regulation effect of broccoli is achieved, using sucrose solution as a cold-resistant agent can reduce the cost of cold-resistant agents by 38% compared with brown sugar solution, which has obvious cost advantages.

[0065] 2. Biomass of Chinese cabbage, rapeseed, corn and soybean seedlings

[0066] The effects of 0.5g / L sucrose on the growth of Chinese cabbage, rapeseed, corn and soybean under low temperature stress (5℃) are shown in the following table.

[0067] Table 3 Effects of sucrose on aboveground and root biomass of crop seedlings

[0068]

[0069] The results in Table 3 show that 0.5 g / L sucrose pretreatment significantly increased the biomass of the aboveground and root systems of the four crop seedlings, and increased the root-to-shoot ratio of the four crop seedlings; 0.5 g / L sucrose pretreatment of the four crops at the seedling stage can play a good role in promoting root growth and seedling strength and improving growth.

[0070] At the same time, brown sugar was used as a parallel control test, and the results were as follows:

[0071] Table 4 Comparison of aboveground fresh weight of Chinese cabbage, rapeseed, corn and soybean seedlings pretreated with two preparations

[0072]

[0073] Table 4 is a comparison of the two preparations pre-treated on the other four crops. It can be seen that the results of the cold resistance regulation test of four crops, Chinese cabbage, rapeseed, corn and soybean, all show that the aboveground fresh weight of the four main crops pre-treated with 0.5g / L sucrose solution and 1g / L brown sugar solution is relatively close, indicating that when the two preparations are applied exogenously to achieve similar cold resistance and growth promotion effects, the amount of sucrose is only 50% of that of brown sugar. The cost of food-grade brown sugar and sucrose is 6,500 yuan / ton and 4,000 yuan / half ton, respectively. When the same cold resistance regulation effect of Chinese cabbage, rapeseed, corn and soybean is achieved, the use of sucrose solution as a cold resistance agent can reduce the cost of cold resistance agent by 38% compared with brown sugar solution, which has obvious cost advantages.

[0074] 3. MDA and electrical conductivity of Chinese cabbage, rapeseed, corn and soybean leaves under low temperature stress

[0075] MDA is a basic indicator for evaluating the low temperature tolerance of plants. When plants are subjected to low temperature stress, the cell membrane is the first part to feel the low temperature stress. Low temperature stress will aggravate the lipid peroxidation reaction of plant cell membranes and increase the MDA content, which will cause the loss of cell membrane selective permeability, electrolyte exudation, and increased relative conductivity. The MDA content was determined by visible spectrophotometry, and the detection kit was purchased from Beijing Solebow Technology Co., Ltd. The relative conductivity was measured by a conductivity meter. The analysis results are shown in the following table.

[0076] The results showed that pretreatment with a given concentration of sucrose solution could greatly reduce the MDA content in crop leaves and significantly reduce the electrolyte exudation rate in crop leaves.

[0077] 4. SPAD values ​​of Chinese cabbage, rapeseed, corn and soybean leaves

[0078] Low temperature stress can inhibit the synthesis of chlorophyll in plants. The SPAD value of chlorophyll content in leaves of Chinese cabbage, rapeseed, corn and soybean was tested using a SPAD502 chlorophyll meter.

[0079] Chlorophyll is an important indicator of plant photosynthetic capacity. The SPAD values ​​of relative chlorophyll content in Chinese cabbage, rapeseed, corn and soybean are shown in the following table.

[0080] Table 5 Effects of sucrose on leaf conductivity, MDA and SPAD of crop seedlings

[0081]

[0082] The results showed that applying a certain concentration of sucrose solution to the leaves of Chinese cabbage, rapeseed, corn and soybean before and after low temperature stress (cold wave) could effectively increase the SPAD value of Chinese cabbage, rapeseed, corn and soybean leaves.

[0083] Table 6 Comparison of leaf conductivity and MDA of seedlings of four crops pretreated with two preparations

[0084]

[0085] Table 6 is a comparison of membrane lipid damage in leaves of Chinese cabbage, rapeseed, corn and soybean seedlings pretreated with the two preparations. It can be seen that the effects of the two preparations on alleviating chilling stress on the four crops are highly consistent with their chilling resistance and growth-promoting effects (Table 4). The results of leaf membrane lipid damage analysis showed that the MDA values ​​and relative conductivity of the leaves of the seedlings of the four main crops pretreated with sucrose solution at a concentration of 0.5 g / L and brown sugar solution at a concentration of 1 g / L were relatively close, indicating that when the two preparations were applied exogenously to achieve similar effects in alleviating low temperature chilling stress, the amount of sucrose required was only 50% of that of brown sugar, and the cost advantage of sucrose in chilling resistance regulation was obvious.

[0086] 5. Fluorescence parameters of Chinese cabbage, rapeseed, corn and soybean leaves

[0087] Thanks to the progress of non-destructive monitoring technology for plants, changes in plant chlorophyll fluorescence parameters can monitor the operation of plant photosystems. Fv / Fm reflects the potential maximum photochemical efficiency index of plant PSII. Fo, Fm, Fv, and Fv / Fo reflect initial fluorescence, maximum fluorescence, variable fluorescence, and potential activity of PSII, respectively. ABS / RC, TRo / RC, ETo / RC, and DIo / RC ensure leaf light absorption, capture, transmission, and dissipation, respectively. The monitoring results of a series of chlorophyll fluorescence parameters for Chinese cabbage, rapeseed, corn, and soybean leaves are shown in the following table.

[0088] The analysis results of chlorophyll fluorescence parameters, chlorophyll content, and light energy absorption, transfer, and utilization of leaves of Chinese cabbage, rapeseed, corn, and soybean showed that pretreatment with 0.5 g / L sucrose solution could greatly alleviate the degradation of photosynthetic pigments in plants under low temperature stress, maintain the functional and structural integrity of PSII, alleviate the pressure of excitation energy on the photosynthetic system, increase the proportion of light energy used for photochemical reactions, and improve plant light energy absorption and utilization.

[0089] Table 7 Effects of sucrose on fluorescence parameters and photochemical efficiency of crop seedling leaves

[0090]

[0091] Table 8 Effects of sucrose on light energy absorption, transfer and utilization in crop seedling leaves

[0092]

[0093] At the same time, brown sugar was used as a parallel control test, and the results were as follows:

[0094] Table 9 Comparison of fluorescence parameters and photochemical efficiency of leaves of four crop seedlings pretreated with two preparations

[0095]

[0096] Table 9 shows the comparison of fluorescence parameters and photochemical efficiency of leaves of Chinese cabbage, rapeseed, corn and soybean seedlings pretreated with the two preparations. It can be seen that the pretreatment with 0.5 g / L sucrose solution and the pretreatment with 1 g / L brown sugar solution achieved the same effect of reducing photosynthetic damage of crop leaves and increasing leaf photochemical efficiency on the four crops.

[0097] Table 10 Comparison of light energy absorption, transfer and utilization of leaves of four crop seedlings pretreated with two preparations

[0098]

[0099] Table 10 is a comparison of the light energy absorption, transfer and utilization indicators of the leaves of Chinese cabbage, rapeseed, corn and soybean seedlings pretreated with the two preparations. It can be seen that the pretreatment with 0.5g / L sucrose solution and the pretreatment with 1g / L brown sugar solution achieved the same effect of reducing leaf light energy absorption and capture, increasing leaf light energy transfer, and reducing leaf light energy dissipation on the four crops.

[0100] The results of the above tests show that sucrose can enhance the tolerance of Chinese cabbage, rapeseed, corn and soybean to low temperature and chilling damage, effectively alleviate plant damage caused by low temperature and chilling damage, significantly improve the absorption, transmission and utilization of light energy in plant leaves, effectively improve the potential and actual photochemical efficiency of plant leaves, and increase the stability of photosynthetic pigments and chloroplast pigment synthesis in leaves of major crops under low temperature stress. Sucrose raw materials are easily available, green and pollution-free, and the cold resistance regulation method is simple and easy to implement, which is suitable for crop protection against low temperature and chilling damage.

[0101] At the same time, based on the experimental results of broccoli, Chinese cabbage, rapeseed, corn and soybeans, it can be seen that compared with brown sugar, sucrose, at half the dosage, shows the same effect as brown sugar in alleviating the membrane lipid damage of crop leaves under low temperature stress, optimizing the absorption and utilization of light energy by crop leaves, and improving the growth of seedlings of crops under cold stress. In addition, when achieving the same crop cold resistance regulation effect, the cost of cold resistance agent using sucrose is reduced by 38% compared with using brown sugar, which has obvious cost advantages.

[0102] Although the present invention has been described in detail above with general descriptions and specific embodiments, it is obvious to those skilled in the art that some modifications or improvements may be made thereto based on the present invention. Therefore, these modifications or improvements made without departing from the spirit of the present invention all fall within the scope of protection claimed by the present invention.

Claims

1. A method for improving the cold resistance of crops, characterized in that: Use cold-resistant preparations for root irrigation of crops at the seedling stage; The cold-resistant preparation is a sucrose aqueous solution with a concentration of 0.5 g / L to 2 g / L.

2. The method according to claim 1, characterized in that The crops are one or more of corn, soybean, rapeseed, broccoli and Chinese cabbage.

3. The method according to claim 1 or 2, characterized in that: The time for rhizosphere irrigation is 2-6 days before the onset of low temperature stress, and the irrigation amount is 50-100 mL / plant.

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