Wheat powdery mildew prevention and control material as well as preparation method and application thereof

Abstract

The invention discloses a wheat powdery mildew prevention and control material and a preparation method and application thereof, and relates to the technical field of wheat powdery mildew prevention and control, the prevention and control material comprises the following raw materials: chitosan, rhamnolipid, nano SiO2 and a 1% (v / v) glacial acetic acid aqueous solution, and the volume of the glacial acetic acid aqueous solution with the volume concentration of 1% is taken as a benchmark. The concentration of chitosan is 1-3% (m / v), the concentration of rhamnolipid is 1-3% (m / v), and the concentration of nano SiO2 is 1-3% (m / v). The prevention and control effect of the prevention and control material is remarkable, after the prevention and control material is sprayed, the wheat powdery mildew attack severity is reduced by 97% or above, and the prevention and control material has no influence on normal field growth and reproduction of wheat and is harmless to the environment, so that safe and stable yield and quality of wheat are guaranteed.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of wheat powdery mildew prevention and control, and particularly relates to a wheat powdery mildew prevention and control material and a preparation method and application thereof. BACKGROUND

[0002] Wheat is one of the three major crops in the world, and its yield is only inferior to corn and rice, and it is widely planted in the world. Wheat is rich in nutrients, including starch, protein and vitamins, and foods made from wheat are often used as staple food. In the field production process, wheat is easily affected by various diseases, pests and weeds, among which Blumeria graminis f. sp. tritici of Gramineae can cause white powdery spots on wheat leaves, i.e. wheat powdery mildew. Wheat powdery mildew often occurs in warm and humid areas, and is a worldwide wheat disease. The main disease sites of wheat are leaves and leaf sheaths, and there are very obvious powdery mildew spores on them. Due to the large degradation of chlorophyll in the disease site and the rapid reduction of photosynthetic area, the wheat photosynthesis is seriously damaged, which greatly affects the yield and quality of wheat. When the disease occurs, it can cause yield loss of 5-45%, and the heavy disease field can be as high as more than 50%, and even cause absolute yield.

[0003] At present, wheat powdery mildew is mainly prevented and controlled by selecting and breeding disease-resistant excellent varieties, and using chemical fungicides and adopting reasonable cultivation measures as auxiliary methods. In different geographical and ecological environments, wheat powdery mildew and host wheat have long-term interaction, form different physiological races, and the toxicity varies quickly, and various strains can be quickly formed. Pathogenicity-related genes can be used as candidate genes for wheat resistance improvement. The improvement of plant disease resistance is closely related to the expression of pathogenicity-related proteins. Inducing PR gene expression in Arabidopsis, rice and soybean, it is found that they have resistance to different pathogens. Due to the rapid variability of wheat powdery mildew strains, the resistant wheat varieties produced by research are generally difficult to control new types of powdery mildew strains after 3-5 years. Therefore, spraying fungicides is still an effective measure to prevent and control wheat powdery mildew. It is urgent to develop a high-efficiency, green and environment-friendly wheat powdery mildew prevention and control agent. SUMMARY

[0004] The technical problem to be solved by the present application is how to safely and greenly prevent and control wheat powdery mildew.

[0005] The present application solves the above technical problems by the following technical means:

[0006] A wheat powdery mildew prevention and control material, raw materials of which include chitosan, rhamnolipid, nano silicon dioxide (SiO2) and 1% (v / v) glacial acetic acid aqueous solution, and the mass concentration of chitosan is 1-3% (m / v), the mass concentration of rhamnolipid is 1-3% (m / v), the mass concentration of nano SiO2 is 1-3% (m / v), and the rest is 1% (v / v) glacial acetic acid aqueous solution.

[0007] Preferably, the rest is 1% (v / v) glacial acetic acid aqueous solution.

[0008] Preferably, a wheat powdery mildew prevention and control material, raw materials of which include chitosan, rhamnolipid, nano silicon dioxide (SiO2) and 1% (v / v) glacial acetic acid aqueous solution, and the mass concentration of chitosan is 1-3% (m / v), the mass concentration of rhamnolipid is 1-3% (m / v), the mass concentration of nano SiO2 is 1-3% (m / v), and the rest is 1% (v / v) glacial acetic acid aqueous solution.

[0009] Preferably, the mass concentration of chitosan is 1-2%, the mass concentration of rhamnolipid is 1-2%, and the mass concentration of nano SiO2 is 1%.

[0010] Preferably, the mass ratio of chitosan, rhamnolipid and nano SiO2 is 1-3:1-3:1-3.

[0011] Preferably, the mass ratio of chitosan, rhamnolipid and nano SiO2 is 1-2:1-2:1.

[0012] Preferably, the mass ratio of chitosan, rhamnolipid and nano SiO2 is 1:1:1 or 2:1:1 or 2:2:1.

[0013] Preferably, the concentration of chitosan is 1% (m / v), the concentration of rhamnolipid is 1% (m / v), and the concentration of nano SiO2 is 1% (m / v).

[0014] When the concentration of chitosan, nano SiO2 and rhamnolipid required for formulating the reagent is 1% (m / v), and the rest is 1% (v / v) glacial acetic acid aqueous solution, the prevention and control effect is stronger, and the prevention and control cost is lower.

[0015] The application also provides a preparation method of the wheat powdery mildew prevention and control material, which comprises the following steps: uniformly mixing chitosan, rhamnolipid, nano SiO2 and 1% (v / v) glacial acetic acid aqueous solution to obtain the wheat powdery mildew prevention and control material.

[0016] Preferably, the preparation method of the wheat powdery mildew prevention and control material comprises the following steps: mixing 1% by volume concentration of an ice acetic acid aqueous solution with chitosan, stirring once until the chitosan is completely dissolved, adding nano-SiO2 and rhamnolipid, and stirring twice to obtain the wheat powdery mildew prevention and control material.

[0017] Beneficial effects: Compared with the prior art, the wheat powdery mildew prevention and control effect is enhanced, the severity of wheat powdery mildew can be reduced by more than 97% after the material is sprayed, the preparation method of the material is simple and fast, the cost is low, the material can be prepared in large quantities, the wheat powdery mildew prevention and control effect is excellent, the material is environmentally friendly and easy to biodegrade.

[0018] Preferably, the rotation speed of the first stirring and the second stirring is 400-1500 r / min.

[0019] Preferably, the temperature of the first stirring and the second stirring is 40-80 DEG C, the time of the first stirring is 2-5 min, and the time of the second stirring is 0.2-2 h.

[0020] The application further provides an application of the wheat powdery mildew prevention and control material in wheat powdery mildew prevention and control.

[0021] The application further provides a wheat powdery mildew prevention and control agent containing the wheat powdery mildew prevention and control material.

[0022] The application sprays the composite material formed by "chitosan-rhamnolipid-nano-SiO2" on the leaf of the wheat plant which has grown for 6 days after germination, which not only forms an isolation film on the surface of the wheat leaf, but also inhibits the growth of the powdery mildew fungus. Rhamnolipid and nano-SiO2 can improve the durability and homogeneity of the isolation film formed by the composite material on the wheat leaf, increase the action area and action time of the material on the leaf, and have the characteristics of inhibiting the growth of fungi, so as to produce antagonistic effect on the wheat powdery mildew fungus. By mixing nano-SiO2 and rhamnolipid, a nano-fluid rhamnolipid-chitosan solution is prepared, the nano-particles in the solution are considered as potential wetting improvers, which can change the wetting property of the material from oil-wetting state to water-wetting state, so as to promote the exertion of the efficacy of the composite material. After the composite material is sprayed, it can combine with the cell wall and cell membrane surface material of the parasitic powdery mildew fungus, change the permeability of the cell wall and cell membrane surface material, and cause the lysis and death of the fungus. In addition, the composite material can stimulate the wheat plant to produce a defense mechanism and secrete related anti-pathogen hormones, so as to achieve a more significant powdery mildew prevention and control effect.

[0023] Chitosan is a natural polysaccharide obtained by removing part of the acetyl group of chitin, which has many excellent properties, such as good biodegradability, non-toxicity, etc. At the same time, the long hydrophobic alkyl chain in the molecular structure of chitosan has a hydrophobic affinity with the phospholipids on the cytoplasmic membrane of fungi, causing damage to the cytoplasmic membrane, thereby having antibacterial properties. According to these characteristics, it can be widely used in the field of agriculture to participate in the synthesis of environmentally friendly pesticides. Chitosan not only has a strong inhibitory effect on fungi, but also has good film-forming properties. After spraying, it is easy to form a layer of isolation film at the sprayed site, thereby preventing the infection and growth of powdery mildew on wheat leaves.

[0024] Nano-SiO2 is a kind of stable acidic inorganic compound with wide application, often used to make glass, optical fiber, etc. Nano-SiO2 has the characteristics of large specific surface area, high stability, good biocompatibility, etc. and is applied to the field of agricultural pest control. Due to its large specific surface area, nano-SiO2 particles can greatly improve the loading capacity of active ingredients of pesticides, and at the same time, it can improve the utilization rate of pesticides by enhancing the adsorption of pesticides on the surface of some leaves. Nano-SiO2 particles can act as a biological stimulant, inducing the whole body defense response of plants after spraying, thereby conferring resistance to pathogens. After spraying, nano-SiO2 can cross-link with hemicellulose in the cell wall of the sprayed site to form a silica double cutin layer complex, thereby forming a barrier to prevent the infection of powdery mildew. In addition, nano-silicon dioxide can activate defense-related enzymes such as peroxidase and chitinase, promote the synthesis of antibacterial compounds such as phenols and flavonoids, and also improve the biochemical resistance of plants to pathogens by controlling the production of hormones such as salicylic acid and ethylene.

[0025] Rhamnolipid is a biological metabolic glycolipid anion biosurfactant produced by Pseudomonas or Burkholderia, which naturally exists in water, soil and plants. Due to its long research time, its application range is also relatively wide and mature, with good chemical and biological properties, oil and water amphiphilicity, which can reduce the surface tension of water, often used as emulsifier, foaming agent and wetting agent, which can be applied to pesticides to play the role of wetting, spreading and penetration, so that the composite material can better contact the sprayed site, thereby achieving better material control effect. At the same time, rhamnolipid can interact with the lipid components of the bacterial membrane, thereby inducing the formation of pores and ion channels, interfering with the integrity and permeability of the bacterial membrane, and lysing the bacteria. Rhamnolipid biosurfactant has stable chemical properties and can be used in extreme conditions of temperature, pH and salinity, and is non-toxic itself, which can be biodegraded to achieve environmentally friendly effect.

[0026] Rhamnolipid has a synergistic effect with chitosan and nano-SiO2. The addition of rhamnolipid and nano-SiO2 can reduce the surface tension of the original chitosan solution after spraying on the surface of the wheat leaf, increase the action area and retention time, thereby reducing the combination and infection of the powdery mildew on the leaf, increasing the action time of the sprayed material on the leaf, and thus enhancing the prevention and control effect of the material on the powdery mildew.

[0027] The obtained powdery mildew prevention and control material is uniformly sprayed on the leaves of the wheat plants grown for 6 days after germination by using a spray pot, and a prevention and control isolation film is formed on the wheat leaves to prevent and control the occurrence and development of the powdery mildew of wheat.

[0028] The present application forms a composite material by mixing chitosan, rhamnolipid and nano-SiO2 of suitable concentrations, and sprays it on the leaves of the wheat plants grown for 6 days after germination, stimulates the wheat plants to produce a defense mechanism and secrete related anti-pathogen hormones, and at the same time, the composite material combines with the cell wall, cell membrane surface material of the parasitic powdery mildew, changes the permeability, and lysates the pathogenic bacteria, so as to achieve an effective prevention and control effect on the powdery mildew.

[0029] Chitosan, rhamnolipid and nano-SiO2 complement each other, not only can form a large area of persistent isolation film on the wheat leaves, but also can inhibit the growth of the powdery mildew of wheat, greatly reducing the opportunity of the powdery mildew to combine and infect on the leaves, and the prevention and control effect on the powdery mildew is excellent.

[0030] The preparation method of the powdery mildew prevention and control material in the present application is simple, fast, environment-friendly, green and safe, and the cost is low, which can be used on a large scale, and the effect is remarkable. Compared with the existing prevention and control means of the powdery mildew of wheat, the prepared prevention and control material has a stronger prevention and control effect on the powdery mildew of wheat, and is low in price, easy to obtain and harmless to the environment.

[0031] Compared with the existing prevention and control technology of the powdery mildew of wheat, the prevention and control effect of the present application is more remarkable, the severity of the powdery mildew of wheat can be reduced by more than 97% after spraying, and the normal growth and reproduction of wheat in the field are not affected, and the environment is harmless, so as to ensure the safety and stability of the yield and quality of wheat. The present application has the advantages of being natural, green, environment-friendly, high-efficiency, and can be used for large-area prevention and control of the powdery mildew in the field. BRIEF DESCRIPTION OF DRAWINGS

[0032] Figure 1 The results of treating the leaves of the wheat plants grown for 6 days after germination with different spraying materials in the present application comparative example 1 (a), comparative example 2 (b), comparative example 3 (c), comparative example 4 (d), comparative example 5 (e), comparative example 6 (f), comparative example 7 (g), comparative example 8 (h), example 1 (i), example 2 (j), example 3 (k), and example 4 (l) are shown in the following figures;

[0033] Figure 2The result chart of typical leaf of the wheat plant treated with different spraying materials in the present application Comparative Example 1 (a), Comparative Example 2 (b), Comparative Example 3 (c), Comparative Example 4 (d), Comparative Example 5 (e), Comparative Example 6 (f), Comparative Example 7 (g), Comparative Example 8 (h), Example 1 (i), Example 2 (j), Example 3 (k), Example 4 (l) after germination and growth for 6 days;

[0034] Figure 3 The result chart of wheat disease severity determination of the leaf of the wheat plant treated with different spraying materials in the present application Comparative Example 1 (a), Comparative Example 2 (b), Comparative Example 3 (c), Comparative Example 4 (d), Comparative Example 5 (e), Comparative Example 6 (f), Comparative Example 7 (g), Comparative Example 8 (h), Example 1 (i), Example 2 (j), Example 3 (k), Example 4 (l) after germination and growth for 6 days;

[0035] Figure 4 The wheat powdery mildew prevention and control effect of the leaf of the wheat plant treated with different spraying materials in the present application Comparative Example 1 (a), Comparative Example 2 (b), Comparative Example 3 (c), Comparative Example 4 (d), Comparative Example 5 (e), Comparative Example 6 (f), Comparative Example 7 (g), Comparative Example 8 (h), Example 1 (i), Example 2 (j), Example 3 (k), Example 4 (l) after germination and growth for 6 days. DETAILED DESCRIPTION

[0036] In order to make the objects, technical solutions and advantages of the embodiments of the present application clearer, the following will combine the embodiments of the present application to make a clear and complete description of the technical solutions in the embodiments of the present application. Obviously, the described embodiments are some embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the protection scope of the present application.

[0037] The test materials and reagents used in the following embodiments, unless otherwise specified, can be obtained from commercial channels.

[0038] If the specific technology or condition is not specified in the embodiments, it can be carried out according to the technology or condition described in the literature in the art or according to the product instruction.

[0039] Example 1

[0040] A wheat powdery mildew prevention and control material, the raw materials of which are chitosan, nano-SiO2, rhamnolipid and 1% (v / v) ice acetic acid aqueous solution, the mass ratio of chitosan: nano-SiO2: rhamnolipid = 1: 1: 1, the concentration of the selected chitosan, nano-SiO2 and rhamnolipid in the ice acetic acid aqueous solution is all 1% (m / v), and the rest is 1% (v / v) ice acetic acid aqueous solution.

[0041] The preparation method of the wheat powdery mildew prevention and control material specifically comprises the following steps:

[0042] (1) First, prepare 1% (v / v) concentration of ice acetic acid aqueous solution;

[0043] (2) According to the volume of the prepared ice acetic acid aqueous solution, a certain amount of chitosan is weighed according to 1% mass volume concentration, and then added into the 1% (v / v) ice acetic acid aqueous solution, and stirred at 1000 r / min and 60°C for 5 min until the chitosan is completely dissolved;

[0044] (3) According to the volume of the prepared ice acetic acid aqueous solution, a certain amount of rhamnolipid and nano-SiO2 are weighed according to 1% mass volume concentration, and then added into the dissolved chitosan-ice acetic acid solution, and stirred at 1000 r / min and 60°C for 30 min, to obtain the wheat powdery mildew prevention and control material.

[0045] Pot-cultured wheat cultivation:

[0046] (1) Select wheat seeds with full grains and undamaged embryos, and disinfect and wash the seeds with 75% alcohol for 3 min, and then rinse the seeds with water for 3-5 times until there is no residual alcohol solution on the seeds;

[0047] (2) Pour the disinfected and washed wheat seeds into a culture dish covered with filter paper, add sterile water to wet the bottom of the wheat seeds, and then germinate the seeds at room temperature for 48 h, and pay attention to water supplement during the period;

[0048] (3) Select well-germinated wheat grains, and plant the grains in 10cm×10cm×10cm seedling pots, plant 20 grains in each pot, and set 3 pots of wheat in each treatment group and control group;

[0049] (4) Maintain the suitable temperature (15-24°C) and humidity (60-70%) for the growth of wheat seedlings, and after transplanting, grow the seedlings for 6 days, and then perform subsequent experimental spraying treatment.

[0050] Pot-cultured wheat material spraying treatment:

[0051] Spray the prepared prevention and control material on the wheat leaves at a spraying amount of 10cm 2 / mL, so that the material is uniformly distributed on the wheat leaves, and then wait for the material to dry on the wheat leaves, and then perform subsequent wheat powdery mildew inoculation.

[0052] Wheat pot-cultured powdery mildew inoculation and data statistics after material spraying:

[0053] (1) In the laboratory test box, the spores of Blumeria graminis f. sp. Tritici (the original strain was provided by Professor Wang Xiue of Nanjing Agricultural University, which was collected from the field in Nanjing City, Jiangsu Province, China (Lat 31°14”N to 32°37”N, Lng 118°22”E to 119°14”E), and the publicly known and commonly used material Two members of TaRLK family confer powdery mildew resistance in common wheat. BMC Plant Biology (2016) 16:27;

[0054] (2) The spores of powdery mildew on the leaves of living wheat seedlings were directly shaken off by the shaking method and applied to the dried wheat leaves sprayed with the reagent;

[0055] (3) After inoculation with powdery mildew spores, they were placed in an incubator for culture. After 4 days, light-colored spots were visible on the leaf surface, and after another 3 days of culture, a large number of conidia were produced on the wheat leaves;

[0056] (4) The incidence of pot-grown wheat 7 days after treatment was counted (reference: Wheat Powdery Mildew Test Report Investigation Specification: NY / T 613-2002 [S]. China Standard Press, 2002.) (30 leaves were counted for each treatment, with 3 replicates, divided into 13 disease levels according to 0%, 1%, 5%, 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90%, and 100%), and the disease severity was I, where Xi is the different disease levels (0-100%), Si is the number of leaves with disease level Xi, and L is the total number of leaves counted, i.e. 30.

[0057] Statistically, this example can reduce the severity of wheat powdery mildew by 97.6%, effectively reducing the damage of powdery mildew to wheat yield and quality, and effectively ensuring food security.

[0058] Example 2

[0059] A wheat powdery mildew control material, which is different from Example 1 only in that the concentrations of chitosan, nano-SiO2, and rhamnolipid are all 5‰ (m / v), and the rest is 1% (v / v) ice acetic acid aqueous solution.

[0060] The preparation method of the wheat powdery mildew control material, specifically comprising the following steps:

[0061] (1) According to the required amount of spraying material, first prepare 1% (v / v) concentration of ice acetic acid aqueous solution;

[0062] (2) According to the volume of the prepared glacial acetic acid aqueous solution, a certain amount of chitosan was weighed according to the mass-volume concentration of 5 ‰, and then added into the 1% (v / v) glacial acetic acid aqueous solution, stirred at 1000 r / min and 60 ℃ for 5 min until the chitosan was completely dissolved;

[0063] (3) According to the volume of the prepared glacial acetic acid aqueous solution, a certain amount of rhamnolipid and nano-SiO2 was weighed according to the mass-volume concentration of 1% (m / v), and then added into the dissolved chitosan-glacial acetic acid solution, respectively, and stirred at 1000 r / min and 60 ℃ for 30 min.

[0064] The pot-cultured wheat cultivation, material spraying treatment, powdery mildew inoculation and data statistics were the same as in Example 1.

[0065] Example 3

[0066] The raw materials of the wheat powdery mildew prevention and control material in this example were chitosan, nano-SiO2, rhamnolipid and 1% (v / v) glacial acetic acid aqueous solution, and the mass ratio of chitosan: nano-SiO2: rhamnolipid was 2:1:1. The concentration of the selected nano-SiO2 and rhamnolipid in the 1% (v / v) glacial acetic acid aqueous solution was 1% (m / v), the concentration of chitosan in the 1% (v / v) glacial acetic acid aqueous solution was 2% (m / v), and the rest was 1% (v / v) glacial acetic acid aqueous solution.

[0067] The preparation method of the wheat powdery mildew prevention and control material specifically included the following steps:

[0068] (1) According to the amount of the material to be sprayed, 1% (v / v) glacial acetic acid aqueous solution was prepared first;

[0069] (2) According to the volume of the prepared glacial acetic acid aqueous solution, a certain amount of chitosan was weighed according to the mass-volume concentration of 2%, and then added into the 1% (v / v) glacial acetic acid aqueous solution, stirred at 1000 r / min and 60 ℃ for 5 min until the chitosan was completely dissolved;

[0070] (3) According to the volume of the prepared glacial acetic acid aqueous solution, a certain amount of rhamnolipid and nano-SiO2 was weighed according to the mass-volume concentration of 1% (m / v), and then added into the dissolved chitosan-glacial acetic acid solution, respectively, and stirred at 1000 r / min and 60 ℃ for 30 min.

[0071] The pot-cultured wheat cultivation, material spraying treatment, powdery mildew inoculation and data statistics were the same as in Example 1.

[0072] Example 4

[0073] The raw materials of the wheat powdery mildew prevention and control material of the embodiment are chitosan, rhamnolipid, nano-SiO2 and 1% (v / v) ice acetic acid aqueous solution; the mass ratio of chitosan, rhamnolipid and nano-SiO2 is 2:2:1, the concentration of the selected chitosan and rhamnolipid in the ice acetic acid aqueous solution is 2% (m / v), the concentration of nano-SiO2 in the ice acetic acid aqueous solution is 1% (m / v), and the rest is 1% (v / v) ice acetic acid aqueous solution.

[0074] The preparation method of the wheat powdery mildew prevention and control material specifically comprises the following steps:

[0075] (1) According to the required amount of sprayed material, first prepare 1% (v / v) ice acetic acid aqueous solution;

[0076] (2) According to the volume of the prepared ice acetic acid aqueous solution, a certain amount of chitosan with a concentration of 2% (m / v) is weighed and added into the ice acetic acid aqueous solution, and stirred at 1000 r / min and 60°C for 5 min until the chitosan is completely dissolved;

[0077] (3) According to the volume of the prepared ice acetic acid aqueous solution, a certain amount of rhamnolipid with a concentration of 2% (m / v) and a certain amount of nano-SiO2 with a concentration of 1% (m / v) are weighed and added into the dissolved chitosan-ice acetic acid solution, respectively, and stirred at 1000 r / min and 60°C for 30 min.

[0078] The pot-cultured wheat cultivation, material spraying treatment, powdery mildew inoculation and data statistics are the same as those of Example 1.

[0079] Comparative Example 1

[0080] The difference between the comparative example and Example 1 is that no wheat powdery mildew prevention and control material is sprayed.

[0081] Comparative Example 2

[0082] The difference between the comparative example and Example 1 is that the wheat powdery mildew prevention and control material does not contain rhamnolipid and nano-SiO2, i.e., it only contains 1% chitosan (m / v) and the rest is 1% (v / v) ice acetic acid aqueous solution.

[0083] Comparative Example 3

[0084] The difference between the comparative example and Example 1 is that the wheat powdery mildew prevention and control material does not contain nano-SiO2 and chitosan, i.e., it only contains 1% rhamnolipid (m / v) and the rest is 1% (v / v) ice acetic acid aqueous solution.

[0085] Comparative Example 4

[0086] The difference between the present comparative example and Example 1 is that the wheat powdery mildew prevention and control material does not contain rhamnolipid and chitosan, i.e. only contains 1% nano-SiO2 (m / v), and the balance is 1% (v / v) ice acetic acid aqueous solution.

[0087] Comparative Example 5

[0088] The difference between the present comparative example and Example 1 is that the wheat powdery mildew prevention and control material is 1 (v / v)% ice acetic acid aqueous solution.

[0089] Comparative Example 6

[0090] The difference between the present comparative example and Example 1 is that the wheat powdery mildew prevention and control material does not contain nano-SiO2, i.e. only contains 1% chitosan (m / v), 1% rhamnolipid (m / v), and the balance is 1 (v / v)% ice acetic acid aqueous solution.

[0091] Comparative Example 7

[0092] The difference between the present comparative example and Example 1 is that the wheat powdery mildew prevention and control material does not contain rhamnolipid, i.e. only contains 1% chitosan (m / v), 1% nano-SiO2 (m / v), and the balance is 1% ice acetic acid aqueous solution (v / v).

[0093] Comparative Example 8

[0094] The difference between the present comparative example and Example 1 is that the wheat powdery mildew prevention and control material does not contain chitosan, i.e. only contains 1% nano-SiO2 (m / v), 1% rhamnolipid (m / v), and the balance is 1% ice acetic acid aqueous solution (v / v).

[0095] In the present comparative examples 2-8, the mass / volume concentration of nano-SiO2, rhamnolipid and chitosan is based on the volume of ice acetic acid aqueous solution.

[0096] The pot-grown wheat, material spraying treatment, powdery mildew inoculation and data statistics in Comparative Examples 1-8 are the same as in Example 1.

[0097] Figures 1-2 The results of the wheat seedling leaf treatment in the different comparative examples and examples are shown in the following figures. The control group in Comparative Example 1 was not sprayed with the material for prevention and control, and after seven days, the leaf surface was covered with powdery mildew colonies, and the powdery mildew spots were obvious and vigorous. After spraying the experimental material, the wheat leaf powdery mildew incidence of the different treatment groups was improved. Spraying the new material of the example can effectively block the contact of powdery mildew spores with the wax layer of the wheat leaf, significantly inhibit the germination and differentiation of the wheat powdery mildew, and the leaf growth state is excellent.

[0098] Figures 3-4The disease severity of the wheat seedling stage leaf treated by different materials in the comparative examples and the embodiment is measured, and the prevention and control effect diagram is shown. The disease severity of the control group is 85.67; the disease severity of the chitosan-ice acetic acid solution is 55.34; the disease severity of the rhamnolipid-ice acetic acid solution is 22.34; the disease severity of the nano-SiO2-ice acetic acid solution is 65.78; the disease severity of the 1% ice acetic acid solution is 82; the disease severity of the wheat powdery mildew prevention and control material in the embodiment 1 is 2.06, which is reduced by 97.6% compared with the control group; the disease severity of the embodiments 2-4 is 36.16, 1.74 and 1.5; Figure 4 In the embodiment, the prevention and control effect of the comparative examples 1-8 and the embodiments 1-4 is 0%, 35.4%, 73.92%, 23.22%, 4.28%, 80.54%, 45.51%, 78.14%, 97.6%, 57.80%, 97.97% and 98.25%, respectively; from the above data, it can be seen that the chitosan, the rhamnolipid and the nano-SiO2 can reduce the combination and the invasion of the powdery mildew on the leaf, and ensure the normal growth of the wheat seedling stage. Figure 3 And Figure 4 It can be seen that the combination of the chitosan, the rhamnolipid and the nano-SiO2 can reduce the combination and the invasion of the powdery mildew on the leaf, and ensure the normal growth of the wheat seedling stage.

[0099] The above embodiments are only used to illustrate the technical solutions of the present application, but not limit the present application; although the present application is described in detail with reference to the foregoing embodiments, those skilled in the art should understand that the technical solutions recorded in the foregoing embodiments can be modified, or some technical features can be replaced by the equivalent; and the modification or the replacement does not make the essence of the corresponding technical solution deviate from the spirit and the scope of the technical solutions of the embodiments of the present application.

Claims

1. A material for controlling wheat powdery mildew, characterized in that: Its raw materials include chitosan, rhamnolipin, nano-SiO2 and a 1% volume concentration aqueous solution of glacial acetic acid. Based on the volume of the 1% volume concentration aqueous solution of glacial acetic acid, the mass-volume concentration of chitosan is 1-3%, the mass-volume concentration of rhamnolipin is 1-3%, and the mass-volume concentration of nano-SiO2 is 1-3%.

2. The wheat powdery mildew control material according to claim 1, characterized in that: The chitosan has a mass-volume concentration of 1-2%, the rhamnose glycolipid has a mass-volume concentration of 1-2%, and the nano-SiO2 has a mass-volume concentration of 1%.

3. The wheat powdery mildew control material according to claim 1, characterized in that: The mass ratio of chitosan, rhamnolipin, and nano-SiO2 is 1-2:1-2:

1.

4. The wheat powdery mildew control material according to claim 1, characterized in that: The mass ratio of chitosan, rhamnolipid, and nano-SiO2 is 1:1:1, 2:1:1, or 2:2:

1.

5. A method for preparing a wheat powdery mildew control material as described in any one of claims 1-4, characterized in that: Includes the following steps: The wheat powdery mildew control material was obtained by uniformly mixing chitosan, rhamnolipin, nano-SiO2 and a 1% (v / v) aqueous solution of glacial acetic acid.

6. The method for preparing the wheat powdery mildew control material according to claim 5, characterized in that: The process includes the following steps: mixing 1% (v / v) glacial acetic acid aqueous solution with chitosan, stirring once until the chitosan is completely dissolved, adding nano-SiO2 and rhamnolipid, and then stirring a second time to obtain the wheat powdery mildew control material.

7. The method for preparing the wheat powdery mildew control material according to claim 6, characterized in that: The speed of both the primary and secondary stirring is 400–1500 r / min.

8. The method for preparing the wheat powdery mildew control material according to claim 6, characterized in that: The temperature for the first and second stirring is 40–80°C; the time for the first stirring is 2–5 min, and the time for the second stirring is 0.2–2 h.

9. The application of a wheat powdery mildew control material as described in any one of claims 1-4 in the control of wheat powdery mildew.

10. A wheat powdery mildew control agent, characterized in that, It contains wheat powdery mildew control material as described in any one of claims 1-4.

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