阅读说明：本技术 一种水稻抗寒剂及其应用 (Rice cold-resistant agent and application thereof ) 是由 徐华勤 龙俊江 郑华斌 龙攀 许晓萱 王�华 于 2020-12-17 设计创作，主要内容包括：本发明属于作物栽培技术领域,涉及一种水稻抗寒剂,特别涉及一种以苜蓿和柳树皮提取液为抗寒成分的水稻抗寒剂。一种水稻抗寒剂,包括苜蓿提取液和柳树皮提取液。相较于水杨酸、脯氨酸等纯化学试剂制备的抗寒剂,本发明抗寒剂为植物提取物成分,其成分复杂功能多样,且对植株的综合生长能力更加有利。本发明抗寒剂所含有的抗寒成分来自于植物体内,能较好的进入水稻植株各个器官,提高细胞的渗透浓度,降低水稻体内水的冰点；同时还能提高水稻叶片的光合系统效率和叶绿素含量,因此,可同时适用于水稻种子拌种、苗期叶面喷施和晚稻穗期、灌浆期叶面喷施,提高早稻苗期和晚稻开花期抗寒性能,降低低温冷害天气对水稻的伤害。(The invention belongs to the technical field of crop cultivation, relates to a rice cold-resistant agent, and particularly relates to a rice cold-resistant agent taking alfalfa and willow bark extract as cold-resistant components. A rice cold-resistant agent comprises herba Medicaginis extract and willow bark extract. Compared with the cold-resistant agent prepared by pure chemical reagents such as salicylic acid, proline and the like, the cold-resistant agent is a plant extract component, has complex components and multiple functions, and is more favorable for the comprehensive growth capacity of plants. The cold-resistant component contained in the cold-resistant agent is from the plant body, and can better enter each organ of a rice plant, improve the osmotic concentration of cells and reduce the freezing point of water in the rice body; meanwhile, the photosynthetic system efficiency and the chlorophyll content of rice leaves can be improved, so that the method can be simultaneously suitable for seed dressing of rice seeds, spraying on leaf surfaces in a seedling stage and spraying on leaf surfaces in a spike stage and a grain filling stage of late rice, the cold resistance of early rice in the seedling stage and the flowering stage of late rice is improved, and the damage of low-temperature cold damage weather to the rice is reduced.)

1. A rice cold-resistant agent is characterized by comprising alfalfa extract, willow bark extract, a surfactant and a solvent.

2. The rice cold-resistant agent according to claim 1, wherein the surfactant is tween 80.

3. The rice cold-resistant agent as claimed in claim 2, wherein the rice cold-resistant agent comprises 20-25 parts by weight of alfalfa extract, 20-25 parts by weight of willow bark extract, 801-2 parts by weight of tween and the balance of water.

4. The rice cold-resistant agent according to any one of claims 1 to 3, wherein the extraction method of the alfalfa extract comprises: freezing fresh stem and leaf of herba Medicaginis, pulverizing, extracting with solvent, and filtering.

5. The rice cold-resistant agent as claimed in claim 4, wherein the stem leaves of alfalfa are fresh stem leaves at the initial flowering stage.

6. The rice cold-resistant agent according to claim 4, wherein the cold storage temperature is 4-10 ℃ and the cold storage time is 10-15h, preferably the cold storage temperature is 4-8 ℃.

7. The rice cold-resistant agent according to claim 4, wherein the solvent is water and ethanol; preferably, the amount of water in the solvent is 1.5-2 times of the weight of the stem leaves of the alfalfa, the concentration of the added ethanol is 75%, and the mass of the added ethanol is 10-15% of the weight of the added water.

8. The rice cold-resistant agent as claimed in any one of claims 1 to 3, wherein the extraction method of willow bark extract comprises the steps of: pulverizing willow bark, mixing with solvent, leaching, and filtering.

9. The rice cold-resistant agent according to claim 8, wherein the solvent is a mixture of ethanol, water and butanediol; preferably, the amount of water in the solvent is 3-5 times of the weight of the willow bark; the concentration of the ethanol is 75 percent, and the dosage of the ethanol is 10 to 15 percent of the weight of the added water; the amount of butanediol is 8-10% by weight of the added water.

10. Use of a rice cold-resistant agent according to any one of claims 1 to 9 for the preparation of a double cropping rice cold-resistant agent.

Technical Field

The invention belongs to the technical field of crop cultivation, relates to a rice cold-resistant agent, and particularly relates to a rice cold-resistant agent taking alfalfa and willow bark extract as cold-resistant components.

Background

The double-cropping rice area in the middle and lower reaches of Yangtze river is the main rice production area in China and has important significance for guaranteeing the safe production of grains. In the area, the typical meteorological disasters such as 'late spring cold' and 'cold dew' in spring often cause the double cropping rice to be seriously damaged. The low-temperature cold damage in spring mainly refers to the condition of 'late spring cold' in which the average temperature is less than or equal to 12 ℃ in the early rice sowing or transplanting period for more than 3 days, at the moment, the respiration of seeds or seedlings is increased due to low-temperature stress, the root systems of the seedlings are not fully developed, and more nutrients, particularly water, are consumed than absorbed, so that the phenomena of seed rot, bud rot, seedling shortage and seedling death caused by lack of nutrition and water are caused. The cold dew wind is low temperature weather with the average temperature less than or equal to 20 ℃ (conventional rice) or less than or equal to 22 ℃ (hybrid rice) continuously formed for 3 days or more by the sudden temperature drop of 9-10 months per year. At the time of the positive late rice heading and flowering period, the normal development of pollen is seriously influenced by low temperature, phenomena such as pollination and fertilization obstacle occur, the rate of empty husk is increased, and the late rice heading is slowed down and the grain filling is hindered, so that the yield is seriously reduced. For example, in the cold open wind weather in the middle of 9 months in 2014, the phenomenon of empty rice and blighted grains occurs in a large area in late rice in double-season rice areas such as Yueyang and Changde. The continuous low-temperature weather of 9-10 months in 2020 not only causes slow heading of the late rice, but also seriously affects the filling of the late rice. These cold exposure and low temperature disasters all cause severe late rice yield loss.

In recent years, with the development of breeding technology, most late rice varieties with normal sowing time of 6-25-7-2 days are full of ears before cold dew comes, and the production risk of late rice is reduced. And under the current global warming background, the frequency of low-temperature cold damage weather of double-cropping rice in the middle and lower reaches of Yangtze river is reduced, so that farmers have paralysis and lackluster ideas on the harm defense of the low-temperature cold damage weather of late rice, but the low-temperature cold damage phenomenon is often caused to finally cause large-area late rice yield reduction due to the recent extreme climate. The continuous low-temperature cold damage in 2020 causes severe loss of double-cropping rice at the middle and lower reaches of Yangtze river.

At present, in order to cope with low-temperature disasters of rice in agricultural production, farmers mainly use cold-resistant agents taking abscisic acid and salicylic acid as cold-resistant components, but the cost is higher, and the enthusiasm of the farmers in use is not high under the large background that the grain production benefit is low. The adoption of the mulching film can also play a certain defense effect, but the operation is complex and the large-area use is difficult. Thus, it is desirable that the ingredient of the double cropping rice cold-resistant agent be one that is not needed for its intended use, and that is developed and prepared for immediate use in the preparation of a cold-resistant agent. The double cropping rice cold-resistant agent with low cost, multiple functions, simplicity and practicability is used as a strategic storage technology for coping with natural disasters of grain production, and has important significance for disaster reduction and yield preservation of double cropping rice in south China.

Disclosure of Invention

The invention aims to provide a vegetable extract cold-resistant agent which has obvious cold-resistant effect and can effectively promote the comprehensive growth of rice, and is suitable for direct seeding early rice seed dressing or late rice leaf surface spraying so as to reduce the harm of low-temperature cold damage to the growth of early rice seedling stage and late rice flowering stage.

In order to achieve the above object, the present invention provides the following technical solutions:

a rice cold-resistant agent comprises herba Medicaginis extract and willow bark extract.

Preferably, the rice cold-resistant agent also comprises Tween 80 and a solvent.

Preferably, the rice cold-resistant agent comprises, by weight, 20-25 parts of alfalfa extract, 20-25 parts of willow bark extract, 801-2 parts of tween and the balance of water.

The proportion of the alfalfa extract to the willow bark extract can better exert the mutual synergistic effect of the effective components in the alfalfa and willow bark extract.

Tween 80 was used as a lubricant and surfactant.

Preferably, the extraction method of the alfalfa extract comprises the following steps: freezing fresh stem and leaf of herba Medicaginis, pulverizing, extracting with solvent, and filtering.

Preferably, the stem leaves of alfalfa are fresh stem leaves at the beginning of flowering.

The fresh alfalfa in the initial flowering period is the period with the highest content of the active stress-resistant substances of the alfalfa.

Preferably, the refrigeration temperature is 4-10 ℃, and the refrigeration time is 10-15 h.

Further preferably, the refrigeration temperature is 4-8 ℃.

The plant can generate stress reaction under the adverse circumstances, and the content of the cold-resistant active ingredients can be effectively improved by refrigerating the plant at 4-8 ℃. The temperature of 4 ℃ is the lower limit of the plant active substance for ensuring the physiological activity, and the temperature of 8 ℃ can create a low-temperature stress environment to promote the generation of cold-resistant active ingredients in the alfalfa body.

Preferably, the stem leaves of the alfalfa are crushed into 2-3cm by a straw crusher.

Pulverizing into 2-3cm for extracting effective components of herba Medicaginis.

Preferably, the solvent is water and ethanol

Preferably, the amount of water in the solvent is 1.5-2 times of the weight of the stem leaves of alfalfa, the concentration of the added ethanol is 75%, and the mass of the added ethanol is 10-15% of the weight of the added water.

As an organic solvent, a proper amount of 75% ethanol promotes the dissolution and the uniform mixing of organic components in the stems and leaves of the alfalfa.

Preferably, the leaching time is 5-8h, and the leaching temperature is 25-30 ℃.

The extraction efficiency of the cold-resistant active ingredients in the alfalfa is higher at the temperature and within the time. Too short time, too low temperature and poor extraction effect.

Preferably, the filtration is performed by using 800-1000-mesh gauze.

The size can reduce the impurity after the alfalfa leaching solution is filtered, and the requirement of unmanned aerial vehicle spraying in large-scale production is met.

Preferably, the extraction method of the willow bark extract comprises the following steps: pulverizing willow bark, mixing with solvent, leaching, and filtering.

Preferably, willow bark is pulverized to 10-20 mesh.

The crushing to 10-20 meshes is beneficial to improving the extraction efficiency of the cold-resistant active ingredients in the willow bark.

Preferably, the solvent is a mixture of ethanol, water and butanediol.

Is organic solvent mixed solution, and can better dissolve effective components in willow bark.

Preferably, the amount of water in the solvent is 3-5 times of the weight of the willow bark; the concentration of the ethanol is 75 percent, and the dosage of the ethanol is 10 to 15 percent of the weight of the added water; the content of butanediol is 8-10%

Proper amount of ethanol and butanediol are added into the organic solvent mixed solution, so that the cold-resistant active ingredients in the willow bark can be better dissolved. Experiments prove that the cold-resistant effect of the paint is obviously poor due to different components and proportions of the solvents.

Preferably, the willow bark is crushed and then mixed with a solvent for extraction for 5-8 h.

Preferably, the filtration is performed by using 800-1000 mesh gauze.

The size can ensure that the fineness of the filtered willow bark leachate meets the spraying requirement of an unmanned aerial vehicle in large-scale production, and gauze with the size is available in the market.

Preferably, the rice cold-resistant agent can be used for seed dressing, foliage spraying or both.

The invention also provides application of the rice cold-resistant agent in preparation of the double cropping rice cold-resistant agent.

The invention is further explained below:

alfalfa (latin science name; Medicago sativa L.) is a perennial herbaceous plant of the genus Medicago of the family leguminosae, is the most widely distributed cultivated pasture in the world at present, is mainly distributed in northwest, northeast and southwest areas of China, has the advantages of cold resistance, drought resistance, strong reproducibility, high nutritional value and the like, and is called as the king of pasture. Alfalfa contains multiple antioxidant components, and multiple nutrients such as amino acids, proteins, and mineral elements.

Willow (Latin's name: Salix babylonica L.) is a family Sapindaceae, genus Salix alba, and is mainly produced in temperate regions of the northern hemisphere, with the second lowest in the frigid zone and few in the tropical and southern hemispheres. Willow bark is the cortex part of willow, and ancient China and western countries have records of the willow bark being used as medicine. Willow bark, which contains natural salicin, is absorbed and converted to salicylic acid by enzymes, and is often used to treat pain, fever and gout. Willow bark contains multiple antioxidant components, and multiple nutrients such as organic acids and mineral elements.

However, the prior art does not use the extracts of the two as cold-resistant agents. Experiments prove that the extracts of the alfalfa stem leaves and the willow bark are complex in components and contain various unknown small molecular compounds, although the research does not determine that the extracts play the main component of cold resistance at present, multiple experiments prove that the extracts of the alfalfa stem leaves and the willow bark can mutually promote the cold resistance after being mixed, and the combined effect of the extracts on improving the rice production is obviously superior to that of the cold resistance products sold in the market. And the cost is lower, the practicability is strong, the ecological environment is protected, and good economic benefit, social benefit and ecological benefit are achieved.

The alfalfa leaves used in the method are fresh alfalfa stems in the initial flowering period (the contents of the alfalfa stems and leaves in the initial flowering period are rich), the leaves are extracted after being refrigerated at low temperature (the cold-resistant ingredients in the alfalfa stems and leaves can be promoted to be generated under the low-temperature adverse environment, the content of the cold-resistant active ingredients in the leaching solution is improved), the alfalfa leaching solution also contains various proteins, saccharides, mineral substances, unknown growth promoting factors and the like, and the alfalfa leaching solution has the effects of resisting oxidation, resisting fungi, promoting biological growth and the like. Generally speaking, because of allelopathy of alfalfa stems and leaves, alfalfa leachate often has certain characteristic of inhibiting seed germination, and after the active ingredients in the willow bark extract are mixed with the alfalfa leachate, the stability of a plant membrane system is further protected, the efficiency of a photosynthetic system is improved, the total chlorophyll content is increased, and the like, so that mutual promotion is realized, the cold resistance of rice is improved, and the inhibition effect on seed germination is reduced.

Compared with the cold-resistant agent prepared by pure chemical reagents such as salicylic acid, proline and the like, the cold-resistant agent is a plant extract component, has complex components and multiple functions, and is more favorable for the comprehensive growth capacity of plants. The cold-resistant component contained in the cold-resistant agent is from the plant body, and can better enter each organ of a rice plant, improve the osmotic concentration of cells and reduce the freezing point of water in the rice body; meanwhile, the photosynthetic system efficiency and the chlorophyll content of rice leaves can be improved, so that the method can be simultaneously suitable for seed dressing of rice seeds, spraying on leaf surfaces in a seedling stage and spraying on leaf surfaces in a spike stage and a grain filling stage of late rice, the cold resistance of early rice in the seedling stage and the flowering stage of late rice is improved, and the damage of low-temperature cold damage weather to the rice is reduced.

Compared with the prior art, the invention has the innovativeness that:

1. low cost and strong practicability

The invention takes the extracts of alfalfa and willow bark as the main cold-resistant components, and has lower cost than the cold-resistant agent taking abscisic acid or salicylic acid as the cold-resistant components. And is simultaneously suitable for seed dressing of early rice, spraying in seedling stage, and spraying in heading stage and grouting stage of late rice, has higher cold resistance efficiency to double cropping rice, and is simple and practical in operation compared with cold resistance measures such as plastic film mulching and the like.

2. Multiple components and multiple functions. The invention adopts plant components such as alfalfa leachate, willow bark leachate and the like, contains other small molecular compounds, and can play a more remarkable role in building bodies of rice after being mixed

3. The plant is extracted, and is simple and practical. The invention mainly takes the extracts of the alfalfa and the willow bark as cold-resistant components, the alfalfa is perennial pasture with larger planting area, the willow is also a common landscape garden tree, the alfalfa and the willow are common and easily obtained in daily life, the extraction preparation process is simple to operate and low in cost, and a grower does not need to specially input too much manpower, material resources and financial resources for the cold-resistant agent, so that the requirement of the cold-resistant agent as a strategic storage technology can be met.

Drawings

FIG. 1 shows the effect of different cold-resistant agents on early rice in seedling stage after being affected by low temperature cold damage;

FIG. 2 is a graph showing the effect of different cold-resistant agents on the alleviation of the low temperature effect of late rice during the flowering period;

FIG. 3 shows the effect of spraying cold-resistant agent in field.

Detailed Description

Embodiments of the present invention will be described in detail below with reference to examples, but it will be understood by those skilled in the art that the following examples are only illustrative of the present invention and should not be construed as limiting the scope of the present invention. The examples, in which specific conditions are not specified, were conducted under conventional conditions or conditions recommended by the manufacturer. The reagents or instruments used are not indicated by the manufacturer, and are all conventional products available commercially.

Example 1

Collecting 2kg of fresh leaves of herba Medicaginis subjected to low temperature treatment and cutting into 2-3cm long leaves at the initial flowering stage, adding 4kg of water and 0.4kg of 75% ethanol solution, extracting at 30 deg.C for 7 hr, and filtering with 800 mesh gauze to obtain cold-resistant herba Medicaginis extract.

Pulverizing 2kg of willow bark to 20 mesh, adding 10kg of water, 1kg of 75% ethanol solution and 0.8kg of butanediol, leaching for 7h, and filtering with 800 mesh gauze to obtain cold-resistant willow bark leaching solution.

Mixing 2L of herba Medicaginis leaching solution and 2L of cortex Salicis Babylonicae leaching solution in a container, sequentially adding 100ml of Tween 80 and 6L of water, and stirring at room temperature to obtain the rice cold-resistant agent.

Example 2

The rice cold-resistant agent produced in the above example is used for dressing seeds of early rice:

according to the formula requirement, 10ml of the rice cold-resistant agent is diluted by adding 190ml of water. In order to distinguish the effect of the cold-resistant agent and the single leaching liquid of the alfalfa and the single leaching liquid of the willow bark, 10ml of the alfalfa leaching liquid and the willow bark cold-resistant agent are respectively diluted by adding 190ml of water. In order to distinguish the cold-resistant effect of the cold-resistant agent from the cold-resistant effect of the pure chemical reagent, 200ml of each of 10mmol/L salicylic acid solution and 30mmol/L proline solution is measured according to the conventional dosage.

Selecting early rice variety Luliangyou 996 as main push variety in the middle and lower reaches of Yangtze river, weighing 500g of seeds, fully mixing and standing for 24h with each diluent, sowing 300 seeds after exposure, transferring the seedlings to an incubator for low temperature treatment at 10 ℃ for 5d in the period of two leaves and one heart, then returning to the normal temperature for continuous growth, measuring the plant height at 6d, and measuring the fresh weight and chlorophyll content of overground and underground parts, chlorophyll fluorescence parameters Fv, Fm, Fv/Fm and Fv/F0.

The results are shown in table 1 and fig. 1:

table 1: influence of different cold-resistant agents on seedling growth, chlorophyll and chlorophyll fluorescence parameters after low-temperature treatment of early rice

As can be seen from the above, after the early rice is dressed and sprayed on the leaves, compared with the application of alfalfa leach liquor, willow bark leach liquor, salicylic acid solution, proline solution and clear water, after the mixed cold-resistant agent is applied, compared with the spraying of clear water for comparison, the main indexes of the early rice, such as plant height, overground part fresh weight, underground part fresh weight, chlorophyll content and the like, are all improved, and the comprehensive indexes of chlorophyll fluorescence F0, Fv, Fm, Fv/Fm and Fv/F0 are the best to mix the cold-resistant agent. The invention is proved to have good cold-resistant effect when being used for seed dressing of early rice and foliage spraying in seedling stage.

Example 3: the cold-resistant agent is used for foliage spraying in the low-temperature period of late rice:

according to the formula requirements, the mixed leaching liquor is used for spraying the leaf surfaces of late rice. Taking 100ml of mixed leaching liquor, 1mol/L salicylic acid solution, 30mmol/L proline solution and clear water respectively, adding 20kg of water for dilution, spraying on leaf surfaces 36 hours before cold exposure wind comes, collecting plant samples in fields 3 days after low-temperature weather, measuring plant height and chlorophyll content, and measuring fertilization rate, maturing rate, yield and yield forming factors in later period, wherein the late rice variety is a high-quality rice variety (conventional rice Xiang late long shaped 17 and hybrid rice Shengtaiyou 018) popularized in large area in the middle and lower reaches of Yangtze river, and the results are shown in table 2 and figure 2:

table 2: influence of leaf surface spraying of cold-resistant agent on growth and yield of late rice under low temperature influence

From the above, it can be seen that: when the method is used for foliage spraying before the late rice is sprayed at low temperature, compared with the spraying of clear water, alfalfa leaching liquor, willow bark leaching liquor, salicylic acid solution and proline solution, the maturing rate, the fertilization rate and the yield of the late rice are improved. The invention is proved to have good cold-resistant effect when being used for spraying the late rice foliage, and the comprehensive effect of improving various indexes of rice growth is obviously better, and the yield increase range is higher.

Compared with the cold-resistant agent prepared from alfalfa leaching solution, willow bark leaching solution and pure chemical reagents such as salicylic acid and proline, the cold-resistant agent is more beneficial to the comprehensive growth capacity of plants, and shows that the main components of the cold-resistant agent are alfalfa extracting solution and willow bark extracting solution which can be mutually promoted in a soluble way, so that the cold-resistant capacity of rice is further improved.

Example 4: spraying in field

The invention relates to the main content of a sub-topic 'double cropping rice low-temperature cold damage disaster reduction and yield preservation regulation and control key technology research in the middle and lower reaches of Yangtze river' (2017YFD0300409-2) of a national key research and development project 'main meteorological catastrophe process of a main grain production area and disaster reduction and yield preservation regulation and control key technology', which is developed after 3-year potting and continuous optimization of a field test formula. The cold-resistant agent in the embodiment 1 is taken and sprayed on the leaf surfaces 24-48h before low-temperature weather comes, the same weight of clear water is sprayed in a contrast mode, the research result is shown in a figure 3, and the result shows that: the cold-resistant agent can obviously improve the biomass and the chlorophyll content of rice, reduce the inhibition of low temperature on a leaf photosynthetic system, improve the cold resistance of the rice and realize disaster reduction and yield preservation.

While particular embodiments of the present invention have been illustrated and described, it would be obvious that various other changes and modifications can be made without departing from the spirit and scope of the invention. It is therefore intended to cover in the appended claims all such changes and modifications that are within the scope of this invention.