Application of aspergillus or conidia thereof in prevention and control of spodoptera frugiperda
By optimizing the composition and preparation method of Aspergillus wettable powder, the stability and activity issues of Aspergillus agents in the control of fall armyworm have been solved, providing a highly efficient and stable biological pesticide solution suitable for the control of fall armyworm.
Patent Information
- Application Number
- CN202511575222.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-10-31
- Publication Date
- 2025-12-05
AI Technical Summary
Existing Aspergillus fungicides have problems in controlling fall armyworm, such as the contradiction between drying inactivation and rehydration germination, and the insufficient stability of wettable powders, which limit their large-scale application in agriculture.
A wettable powder containing Aspergillus spore powder, dispersant, wetting agent and carrier was developed. The component ratio and particle size were optimized. Ultraviolet absorbers and antioxidants were added to improve stability. The preparation method is simple and it can be sprayed on the leaves of crops for prevention and control.
It achieves highly efficient insecticidal activity and stability of Aspergillus spores against fall armyworm, with a stability period of more than 12 months at room temperature, making it suitable for diverse agricultural applications.
Smart Images
Figure CN121058697A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of insect repellent technology, specifically relating to the application of Aspergillus or its conidia in the control of fall armyworm. Background Technology
[0002] fall armyworm ( Spodoptera frugiperda Biological pests (BMPs) are a major global agricultural pest, primarily damaging food crops such as corn and rice. Their high reproductive capacity and rapid migration speed pose a serious threat to global agricultural production security. While traditional chemical pesticides can control pests in the short term, long-term use easily leads to increased pesticide resistance, pesticide residues polluting the environment, and harming human health, making them unsuitable for the demands of modern agriculture for green and sustainable development. With the increasing global emphasis on food safety and environmental protection, the development of highly efficient, low-toxicity, and environmentally friendly biological pesticides has become an inevitable trend in the construction of green pest control systems and a core approach to solving the problem of chemical pesticide overuse.
[0003] Microbial pesticides, due to their advantages such as good environmental compatibility, strong target specificity, and easy biodegradability, have shown great potential in the biological control of fall armyworm, with entomopathogenic fungi being an important research direction. Aspergillus (… Aspergillus sp. As a class of highly efficient insect pathogenic fungi, their conidia can penetrate the insect's body wall and enter the body cavity, killing the host through secreted enzymes and secondary metabolites. They hold broad application prospects in controlling pests such as Lepidoptera and Coleoptera. However, the types of biological pesticides currently available for the fall armyworm are still relatively limited, and existing fungal preparations face significant technical bottlenecks: spores in water-based suspensions are easily degraded by ultraviolet light, resulting in a field half-life of less than 5 days; oil-based suspensions are costly and have poor affinity with leaf surfaces, limiting large-scale application; and there is a technological gap in the field of wettable powders, where existing Aspergillus powders exhibit low dry spore survival rates (<40%), poor storage stability, and insufficient germination rates after rehydration, severely hindering the industrialization of Aspergillus strains.
[0004] To address the aforementioned issues, particularly the core bottlenecks faced by Aspergillus strains in formulation development, such as the contradiction between drying inactivation and rehydration germination, and insufficient stability of wettable powders, there is an urgent need to develop a novel Aspergillus formulation that combines high storage stability, rapid wetting, and convenient field application through formulation innovation and technological optimization. This is of great significance for improving the biological control efficacy of fall armyworm, reducing application costs, and promoting the industrialization of microbial pesticides. Simultaneously, it can provide agricultural production with a low-cost, environmentally adaptable, and green control solution, meeting the diverse application needs of small-scale farmers in hilly areas. Summary of the Invention
[0005] Based on this, the application provides an application of Aspergillus or conidiospores thereof with a preservation number of CGMCC No. 42111 in the prevention and treatment of Spodoptera frugiperda, and provides an Aspergillus wettable powder containing Aspergillus spore powder, which also has excellent killing activity and stability on Spodoptera frugiperda.
[0006] In order to achieve the above-mentioned purpose, the application can adopt the following technical solutions: The application provides an application of Aspergillus or conidiospores thereof in the prevention and treatment of Spodoptera frugiperda, Spodoptera frugiperda The preservation number of Aspergillus is CGMCC No. 42111.
[0007] The application provides an Aspergillus wettable powder, which comprises Aspergillus spore powder, a dispersing agent, a wetting agent and a carrier, and the preservation number of Aspergillus is CGMCC No. 42111.
[0008] Preferably, the Aspergillus wettable powder comprises, in terms of mass percentage, 20% to 50% of Aspergillus spore powder, 3% to 10% of the dispersing agent, 1% to 5% of the wetting agent, and the balance of the carrier.
[0009] Preferably, the particle size of the Aspergillus wettable powder is 5 μm to 30 μm.
[0010] Preferably, the Aspergillus wettable powder satisfies one or a combination of the following conditions: (i) the water content of the Aspergillus spore powder is ≤8%; (ii) the number of viable spores of the Aspergillus spore powder is ≥1×10 9 CFU / g; (iii) the dispersing agent is selected from sodium lignosulfonate and / or sodium polycarboxylate; (iv) the wetting agent is selected from sodium dodecyl sulfate and / or Tween-80; (v) the carrier is selected from one or more of talc, kaolin or bentonite.
[0011] Preferably, the Aspergillus wettable powder further comprises a functional auxiliary agent, and the functional auxiliary agent is selected from an ultraviolet absorber and / or an antioxidant.
[0012] More preferably, in the Aspergillus wettable powder, the ultraviolet absorber is selected from fluorescein sodium CBS-X and / or humic acid; and / or the antioxidant is selected from one or a combination of sodium ascorbate, tocopherol or trehalose.
[0013] More preferably, in the Aspergillus wettable powder, the mass percentage of the functional auxiliary agent is ≤1%.
[0014] In still another aspect of the present application, a preparation method of the Aspergillus wettable powder is provided, which comprises: mixing Aspergillus spore powder, dispersing agent, wetting agent and carrier, and crushing to obtain the Aspergillus wettable powder.
[0015] In still another aspect of the present application, a method for preventing and treating Spodoptera exigua in crops is provided, which comprises: spraying the Aspergillus wettable powder of the present application on the leaf surface of crops.
[0016] The Aspergillus in the present application has the following preservation information: preservation agency: China General Microbiological Culture Collection Center (CGMCC); preservation address: No. 3, Beichen West Road, Chaoyang District, Beijing; preservation date: June 26, 2025; preservation number: CGMCC No. 42111; classification and naming: Aspergillus ( Aspergillus sp. ). Aspergillus sp.
[0017] The present application has the following beneficial effects: (1) The Aspergillus ( Aspergillus sp. ) with the preservation number of CGMCC No. 42111 or its conidiospores provided by the present application have excellent insecticidal activity on Spodoptera exigua ( Spodoptera frugiperda ), and the insecticidal activity on Spodoptera exigua can reach more than 99% under the concentration of 1×10 8 spores / mL suspension.
[0018] (2) The Aspergillus wettable powder provided by the present application, which contains the spore powder of the Aspergillus with the preservation number of CGMCC No. 42111, has excellent insecticidal activity on Spodoptera exigua ( Spodoptera frugiperda ) and excellent stability, and the stable period at room temperature is more than 12 months. BRIEF DESCRIPTION OF DRAWINGS
[0019] Figure 1 Figure 1 is a preliminary identification morphological diagram of Aspergillus; wherein, A is a diagram of Aspergillus conidial phialide, B is Aspergillus mycelium and spores, C is a diagram of Aspergillus spores, and D is a diagram of Aspergillus sporulating conidial phialide; Figure 2 Figure 2 is a molecular identification phylogenetic tree of Aspergillus strains; Figure 3 Figure 3 is the toxic effect (immersion method) of Aspergillus spore suspensions with different concentrations on Spodoptera exigua; Figure 4 Figure 4 is a photo of Spodoptera exigua treated with Aspergillus spore suspension for 5 days. DETAILED DESCRIPTION
[0020] The examples are provided to better illustrate the present application, but are not intended to limit the present application to the examples only. Therefore, the skilled in the art can make some non-essential improvements and modifications to the embodiments according to the above disclosure content, which are still within the scope of the present application.
[0021] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the disclosure. Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms "comprises" and / or "comprising," when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and / or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof. As used herein, "and / or" places in the conjunctive sense, can be interpreted as "and / or", unless the context clearly indicates otherwise.
[0022] In a first aspect, the present application provides an application of Aspergillus or its conidiospores in the control of Spodoptera frugiperda (Sf) in grassland. Spodoptera frugiperda The Aspergillus has a preservation number of CGMCC No.42111.
[0023] It should be noted that the Aspergillus (Aspergillus) with the preservation number of CGMCC No.42111 provided in the present application has excellent insecticidal activity on Spodoptera frugiperda (Sf). Aspergillus sp. The Aspergillus (Aspergillus) or its conidiospores has excellent insecticidal activity on Spodoptera frugiperda (Sf). Spodoptera frugiperda 8 The insecticidal activity on Spodoptera frugiperda (Sf) can reach more than 99% under the concentration of 1x10
[0024] In a second aspect, the present application provides an Aspergillus wettable powder, which comprises Aspergillus spore powder, dispersant, wetting agent and carrier. The Aspergillus has a preservation number of CGMCC No.42111.
[0025] It should be noted that the spore powder of the Aspergillus with the preservation number of CGMCC No.42111 can be prepared into Aspergillus wettable powder, which is more conducive to the control of Spodoptera frugiperda (Sf) in the field. In addition, the preparation method of the Aspergillus spore powder is known in the art.
[0026] In some specific examples, the above-mentioned Aspergillus wettable powder comprises, in terms of mass percentage: 20%-50% of Aspergillus spore powder, 3%-10% of dispersant, 1%-5% of wetting agent, and the balance of carrier.
[0027] It should be noted that the mass percentage of each component in the Aspergillus wettable powder in the present application can be prepared according to the above mass fraction, for example, according to the mass percentage, it can include: Aspergillus spore powder 20%-50% (such as 25%, 30%, 35%, 40% or 45% and the like), dispersing agent 3%-10% (for example, 5%, 7% or 9% and the like), wetting agent 1%-5% (such as 2%, 3% or 4% and the like) and the balance carrier.
[0028] In some specific examples, the particle size of the above-mentioned Aspergillus wettable powder is 5-30 μm.
[0029] It should be noted that the particle size of the Aspergillus wettable powder in the present application can be controlled in the range of 5-30 μm, for example, 10 μm, 15 μm, 20 μm or 25 μm and the like, and the particle size controlled in this range is more conducive to the dispersion and suspension of the Aspergillus wettable powder.
[0030] In some specific examples, the above-mentioned Aspergillus wettable powder satisfies one or a combination of the following conditions: (i) the water content of the Aspergillus spore powder is ≤8%; specifically, the water content of the Aspergillus spore powder can be controlled to be ≤8%, for example, 2%, 3%, 4%, 5% or 7% and the like; (ii) the viable spore count of the Aspergillus spore powder is ≥1×10 9 CFU / g; (iii) the dispersing agent is selected from sodium lignosulfonate and / or sodium polycarboxylate; specifically, the dispersing agent in the present application is well known in the art, and is preferably sodium lignosulfonate and / or sodium polycarboxylate; (iv) the wetting agent is selected from sodium dodecyl sulfate and / or Tween-80; specifically, the wetting agent in the present application is well known in the art, and is preferably sodium dodecyl sulfate and / or Tween-80; (v) the carrier is selected from one or more of talc, kaolin or bentonite; specifically, the carrier in the present application is well known in the art, and is preferably one or more of talc, kaolin or bentonite.
[0031] In some specific examples, the above-mentioned Aspergillus wettable powder further comprises a functional auxiliary agent, and the functional auxiliary agent is selected from an ultraviolet absorber and / or an antioxidant.
[0032] It should be noted that the Aspergillus wettable powder in the present application can also add a functional auxiliary agent, such as an ultraviolet absorber and / or an antioxidant, which can increase the stability of the Aspergillus wettable powder.
[0033] In some specific examples, the above-mentioned Aspergillus wettable powder, the ultraviolet absorber is selected from fluorescein sodium CBS-X and / or humic acid.
[0034] In some specific examples, the antioxidant in the above-mentioned Aspergillus wettable powder is selected from one or more combinations of sodium ascorbate, tocopherol or trehalose.
[0035] In some specific examples, the functional adjuvant in the above-mentioned Aspergillus wettable powder has a mass percentage of ≤1%.
[0036] It should be noted that the mass percentage of the functional adjuvant in the present application is ≤1%, for example, 0.1%, 0.5% or 0.7%, etc.
[0037] In a third aspect, an embodiment of the present application provides a preparation method of an Aspergillus wettable powder, which comprises: mixing Aspergillus spore powder, dispersant, wetting agent and carrier, and crushing to obtain the Aspergillus wettable powder.
[0038] It should be noted that the preparation method of the Aspergillus wettable powder in the present application only needs to mix the components and crush them, and the preparation method is simple.
[0039] In a fourth aspect, an embodiment of the present application provides a method for preventing and treating Spodoptera frugiperda in crops, which comprises: spraying the Aspergillus wettable powder on the leaf surface of the crops.
[0040] It should be noted that the Aspergillus wettable powder in the present application can be used to prevent and treat Spodoptera frugiperda by spraying it on the leaf surface of the crops.
[0041] In order to better understand the present application, the content of the present application will be further illustrated below in combination with specific examples, but the content of the present application is not limited to the following examples.
[0042] In the following examples, the preservation number of the Aspergillus used is CGMCC No. 42111, and the isolation, purification and identification process of the Aspergillus strain is provided as follows: (1) Isolation and purification of the strain The target fungus is isolated from the dead red imported fire ant body wall covered with mycelium, which specifically comprises: slowly rinsing the red imported fire ant body wall with sterile water, then inoculating on an SDA plate (containing SDA medium, the same below), and culturing in a 28°C constant temperature incubator; after mycelium grows on the surface of the tissue block, it is timely transferred to a new SDA plate and cultured in an inverted culture in a 28°C incubator, and the purification is repeated for 3 times, then inoculated on an SDA test tube (SDA medium) slant, and after the colony covers the slant, it is stored in a -80°C refrigerator.
[0043] (2) Identification of the strain (2-1) Morphological identification The isolated and purified strain was inoculated on SDA plate and cultured in a constant temperature incubator at 28°C. The color, texture, size, height, surface texture, edge, exudate, etc. of the front and back of the colony were observed daily and photographed. A small amount of spores was picked up with an inoculation needle and inoculated on SDA plate. When the sporulation was mature, a slide was prepared. A small piece of transparent tape with fine texture was clamped with tweezers, and the tape was gently and slowly adhered from the edge to the center of the colony. Then, 95% alcohol was used for fixation and immersion in cotton lan dye. The transparent tape with spore-producing structure was placed with the face up, and a cover glass was gently placed after 3 min to avoid air bubbles. The field of view was found under a low-power microscope, cedar oil or paraffin oil was added, and the structure characteristics of conidial phialides, spore cells and spores were observed under an oil immersion lens. The camera was used to take pictures at 1000 times, and then the pictures were synthesized and arranged, as shown in Figure 1 . Figure 1 It was shown that the strain presented a white milk color on the front of the colony, a tree branch bifurcation, a light yellow back, multiple irregular wheel marks and irregular folds of the colony. In addition, the conidial phialides were of different lengths, the wall was smooth, the top of the conidial phialides was enlarged to form a nearly spherical top cyst, and the conidial phialides were attached with nearly spherical conidia.
[0044] (2-2) Molecular identification After the strain was activated and cultured, about 0.1 g of mycelium was picked into a sterile 1.5 mL centrifuge tube, frozen in liquid nitrogen and ground into powder. The Genewiz Ezup column type fungal genomic DNA extraction kit (Genewiz Biotech Co., Ltd., Shanghai) was used to extract the total DNA of the fungus. After extraction, the total DNA was stored at -20°C for standby.
[0045] Amplification and determination of rDNA ITS sequence: The extracted total DNA of the fungus was used as a template, and PCR amplification was performed using fungal 18rDNA universal primers ITS1 (base sequence 5'-TCCGTAGGTGAACCTGCGG-3') and ITS4 (base sequence 5'-TCCTCCGCTTATTGATATGC-3'). The PCR reaction system (50 μL) was: ddH2O 20 μL, Mix 25 μL, forward primer 1.5 μL, reverse primer 1.5 μL, DNA 2 μL; the reaction conditions were: 94°C pre-denaturation for 3 min, then 35 cycles of 94°C denaturation for 30 s, 56°C annealing for 40 s, 72°C extension for 50 s, and finally 72°C extension for 10 min.
[0046] Gel electrophoresis detection: the PCR product was detected by 1% agarose gel electrophoresis and then sent to Kunming Shuoqin Biotechnology Co., Ltd. for direct sequencing; then molecular phylogenetic analysis: after bidirectional sequencing and sequence splicing, BLAST comparison was performed in the NCBI database, and the strain sequence with higher homology in Gen Bank was selected, MEGA 5.0 and ClustalX 1.83 software were used for multiple sequence alignment analysis, and a phylogenetic tree was constructed, and the Bootstrap was set to 1000 times of repetition to verify its credibility. The gene sequence obtained by purifying, recovering and sequencing the PCR product of the strain (Table 1) was used to construct a Neighbor Joining Tree (see Figure 2 ) by the neighbor joining method. The obtained DNA sequence was subjected to Blast comparison on NCBI. After comparison, it was found that the strain had high similarity with Aspergillus, and the strain and Aspergillus related strains were clustered into a branch, and the genetic distance with the outgroup was far; combined with the morphological identification of the strain, it can be determined that the strain is Aspergillus ( Aspergillus sp. ).
[0047] Table 1 Sequence of PCR product of the strain , In addition, the mycelial growth and sporulation characteristics of the Aspergillus strain with the preservation number of CGMCC No.42111 are as follows: the slope strain of the Aspergillus strain with the preservation number of CGMCC No.42111 is taken out and activated, inoculated on an SDA plate, and cultured in a constant temperature incubator for 10 days, and then the surface conidiospores are scraped off, filtered with sterile water containing 0.1% Tween 80, and prepared into a conidiospore suspension of 1×10 7 spores / mL; 1 mL of the conidiospore suspension is dropped on the center of the SDA plate, evenly spread, and then sealed in a constant temperature incubator for culture, and observed for 10 days, and the diameters of the colonies are recorded every day, and three repeats are used; after 10 days, the conidiospores are filtered with sterile water containing 0.1% Tween 80, and the sporulation amount is determined using a modified Neubauer counting plate. The results show that the colony diameter of the Aspergillus strain reaches (85±2) mm after 7 days of culture, and the sporulation amount of the Aspergillus strain on the SDA reaches 1.2×10 7 spores / mL after 10 days of culture, as shown in Table 2.
[0048] Table 2 Colony growth rate and sporulation amount of the Aspergillus strain .
[0049] Application Example 1 The Aspergillus strain with the preservation number of CGMCC No.42111 is subjected to pathogenicity determination on Spodoptera frugiperda ( Spodoptera frugiperda ), and the specific process is as follows: The slant strain of the Aspergillus strain was taken out for activation, inoculated on a specific medium plate, and cultured in a constant temperature incubator for 10 days, and then the conidia on the surface of the culture medium were scraped off, filtered with sterile water containing 0.1% Tween 80 to collect the conidia, and prepared into a conidial suspension of 1×10 5 spores / mL, 1×10 6 spores / mL, 1×10 7 spores / mL, 1×10 8 spores / mL; then different concentrations of the conidial suspension of Aspergillus were used for soaking treatment of the Spodoptera exigua adults.
[0050] The results are shown in Table 1. Figure 3 The Spodoptera exigua showed an upward trend with time under different treatments, indicating that the Aspergillus strain obtained in the example had excellent insecticidal activity against Spodoptera exigua.
[0051] In addition, the photos of the Spodoptera exigua treated with the Aspergillus conidial suspension for 5 days are shown in Table 2. Figure 4
[0052] Preparation Example 1 Preparation Example 1 (1) Raw material preparation: the Aspergillus strain with the preservation number of CGMCC No.42111 was inoculated on the SMAY culture medium for culture, and the spores were powdered by spray drying, and the moisture content was controlled at 8% to obtain Aspergillus spore powder; (2) Preliminary mixing: 35 g of Aspergillus spore powder, 6 g of sodium lignosulfonate, 2 g of SDS (sodium dodecyl sulfate), 56.5 g of talc, and 0.5 g of ascorbic acid were uniformly mixed by using a high-speed mixer to obtain a mixture; (3) Micro-powder treatment: the mixture was treated by using an air flow crushing device, and the particle size was controlled at 5-30 μm to obtain Aspergillus wettable powder; (4) Packaging and storage: double aluminum foil bags were used for sealing packaging, and the packaged product was placed in a cool and dry place.
[0053] The viable spore content of the Aspergillus wettable powder prepared in Preparation Example 1 was 1.2×10 9 CFU / g, the wetting time was 30 seconds, and the suspension rate was 91%, and the suspension rates of other examples were all less than 91%.
[0054] Preparation Example 2 Preparation Example 2 was substantially the same as Preparation Example 1, except that the raw materials were different, and other aspects were the same as those in Preparation Example 1, and Aspergillus wettable powder was prepared; wherein the raw materials of Preparation Example 2 were: 40 g of Aspergillus spore powder, 5 g of sodium polycarboxylate, 3 g of Tween-80, 51 g of kaolin, 1.2 g of fluorescein sodium CBS-X, and 4 g of tocopherol.
[0055] The particle size of the Aspergillus wettable powder prepared in Preparation Example 2 is 15 μm, and the survival rate of viable spores is 82% after 6 months of storage. The survival rate of other examples is less than 82%.
[0056] Preparation Example 3 Preparation Example 3 is substantially the same as Preparation Example 1, except that the raw materials are different, and the other steps are the same as those in Preparation Example 1, to prepare an Aspergillus wettable powder. In Preparation Example 3, the raw materials are: Aspergillus spore powder 30 g, sodium lignosulfonate 4 g, SDS 1 g, bentonite 64.5 g, and ascorbic acid 0.5 g.
[0057] The Aspergillus wettable powder prepared in Preparation Example 3 has a crop leaf adhesion rate of 83.5% when used for unmanned aerial vehicle spraying, which is higher than that of other examples, indicating that it has high adhesion.
[0058] Preparation Example 4 Preparation Example 4 is substantially the same as Preparation Example 1, except that the raw materials are different, and the other steps are the same as those in Preparation Example 1, to prepare an Aspergillus wettable powder. In Preparation Example 4, the raw materials are: Aspergillus spore powder 50 g, sodium lignosulfonate 7 g, sodium dodecyl sulfate 3 g, and talc powder 40 g.
[0059] The Aspergillus wettable powder prepared in Preparation Example 4 has a 7-day mortality rate of 88% under greenhouse conditions.
[0060] Preparation Example 5 Preparation Example 5 is substantially the same as Preparation Example 1, except that the raw materials are different, and the other steps are the same as those in Preparation Example 1, to prepare an Aspergillus wettable powder. In Preparation Example 5, the raw materials are: Aspergillus spore powder 25 g, sodium lignosulfonate 5 g, SDS 2 g, kaolin 65 g, Tween-80 2 g, and ascorbic acid 1 g.
[0061] The Aspergillus wettable powder prepared in Preparation Example 5 has a spore storage activity of 10 days at 36°C, which is higher than that of other examples, and is suitable for high-temperature climates, with an extended active maintenance period.
[0062] Preparation Example 6 Preparation Example 6 is substantially the same as Preparation Example 1, except that the raw materials are different, and the other steps are the same as those in Preparation Example 1, to prepare an Aspergillus wettable powder. In Preparation Example 6, the raw materials are: Aspergillus spore powder 33 g, sodium lignosulfonate 4 g, Tween-80 2 g, talc powder 60 g, and titanium dioxide 1 g.
[0063] The Aspergillus wettable powder prepared in Preparation Example 6 has improved ultraviolet resistance and an extended field residual period of 12 days.
[0064] Preparation Example 7 Preparation Example 7 is substantially the same as Preparation Example 1, except that the raw materials are different, and the others are the same as Preparation Example 1, to prepare Aspergillus wettable powder; wherein the raw materials of Preparation Example 7 are: Aspergillus spore powder 28g, sodium polycarboxylate 6g, Tween-80 1.5g, bentonite 64.5g.
[0065] The Aspergillus wettable powder prepared in Preparation Example 7 has fine particles and good mixing properties, and can be compounded with fungicides.
[0066] Preparation Example 8 Preparation Example 8 is substantially the same as Preparation Example 1, except that the raw materials are different, and the others are the same as Preparation Example 1, to prepare Aspergillus wettable powder; wherein the raw materials of Preparation Example 8 are: Aspergillus spore powder 22g, sodium lignosulfonate 5g, SDS 2g, talc 70g, BHT (dibutyl hydroxytoluene) 1g.
[0067] The Aspergillus wettable powder prepared in Preparation Example 8 has a spore preservation activity of 7 days at 36°C, and the number of viable spores is 1.29×10 9 CFU / g, which is higher than other examples under the same conditions, so it can exhibit higher spore stability in arid areas.
[0068] Preparation Example 9 Preparation Example 9 is substantially the same as Preparation Example 1, except that the raw materials are different, and the others are the same as Preparation Example 1, to prepare Aspergillus wettable powder; wherein the raw materials of Preparation Example 9 are: Aspergillus spore powder 26g, sodium dodecyl sulfate 5g, sodium lignosulfonate 3g, kaolin 66g.
[0069] The Aspergillus wettable powder prepared in Preparation Example 9 is suitable for high-incidence areas of plant diseases and insect pests.
[0070] Preparation Example 10 Preparation Example 10 is substantially the same as Preparation Example 1, except that the raw materials are different, and the others are the same as Preparation Example 1, to prepare Aspergillus wettable powder; wherein the raw materials of Preparation Example 10 are: Aspergillus spore powder 37g, sodium lignosulfonate 6g, SDS 2g, talc 54g, ascorbic acid 1g.
[0071] The Aspergillus wettable powder prepared in Preparation Example 10 is used for large-area prevention and control of Spodoptera exigua in corn fields, and the control effect reaches 86%.
[0072] Performance test (1) Stability test The Aspergillus wettable powder prepared in Examples 1 to 10 is stable for more than 12 months at room temperature through long-term real storage test.
[0073] (II) Other performance tests The viable spore count, suspension rate, leaf surface adhesion rate, spore germination rate, six-month storage viable spore rate, UV half-illumination time, 7-day mortality rate, and spore preservation activity time under 36°C conditions of the Aspergillus wettable powder prepared in Preparation Examples 1 to 10 are tested respectively, and the specific testing methods are as follows: The detection of viable spore count usually adopts the plate dilution counting method, and the specific steps include: firstly, a certain amount of wettable powder sample is accurately weighed, and a series of dilutions are made with sterile water or suitable buffer to ensure that the spores are fully dispersed; an appropriate amount of diluent is applied to the selective medium plate, and incubated at a suitable temperature (28°C) for 5 days; the colony forming units (CFU) on the plate are counted, and the viable spore count per gram or per milliliter of sample is calculated according to the dilution factor; three repetitions are required for each sample to improve accuracy; this method relies on the germination and growth of spores, so it is necessary to ensure that the medium and culture conditions are suitable for the target microorganism; The suspension rate detection refers to the international standard (CIPAC MT15), and specifically includes: a certain amount of Aspergillus wettable powder sample is added to standard hard water, and the volume is adjusted to 250 mL in a graduated cylinder, and inverted for 30 times to achieve initial suspension; after standing for 30 minutes, 25 mL of the suspension is sucked from 10 cm below the liquid surface with a pipette and transferred to an already constant weight evaporating dish; dried at 105°C to constant weight, and the remaining solid mass is weighed; the suspension rate (%) calculation formula is: (total sample mass - bottom sediment mass) / total sample mass x 100%; high suspension rate indicates good product dispersion stability; The leaf surface adhesion rate needs to simulate the actual spraying conditions, and specifically includes: corn leaves are usually used, and a spray tower is used to uniformly spray under controllable pressure, spray volume and distance; after spraying, the leaves are collected, and the leaf surface is washed with washing liquid to collect the eluate; the spore count in the eluate is determined by microscope counting or plate counting method, and compared with the total amount of spraying (determined by collecting the sprayed liquid with a control filter membrane); adhesion rate (%) = (leaf adhesion spore number / total spraying spore number) x 100%; the environmental conditions (such as temperature, humidity) need to be standardized to reduce errors; The spore germination rate is determined by in vitro culture method, and specifically includes: the Aspergillus wettable powder is applied to agar medium or dropped on a concave glass slide, and incubated at a suitable temperature (25°C) and humidity (≥95%) for 24 hours; sample is taken at regular intervals, and at least 200 spores are observed under a microscope to count the number of germinated spores (the length of the germ tube is greater than the diameter of the spore, which is considered to be germinated). Germination rate (%) = (germinated spore number / total observed spore number) x 100%; a germination promoter (such as glucose) can be used as a positive control to ensure optimal conditions; The storage viability rate is evaluated by accelerated or real-time storage experiments, specifically including: sealing the Aspergillus wettable powder sample in a simulated commercial package (such as an aluminum foil bag) and storing it under constant temperature and humidity conditions (25°C, 60% RH) for 6 months; periodically sampling, detecting the number of viable spores according to the viable spore counting method; the viable spore rate (%) = (the number of viable spores after storage / the initial number of viable spores) x 100%; multiple repetitions need to be set and compared with the initial value, and changes in storage conditions (such as temperature fluctuations) are recorded at the same time; The UV half-illumination death time (UV half- lethal time) is simulated by using an ultraviolet lamp to simulate sunlight ultraviolet rays (such as UV-B band), specifically including: uniformly coating the Aspergillus wettable powder on a sterile petri dish or glass slide, placing it under an ultraviolet lamp (the intensity is usually set to 1.0 mW / cm 2 ), and fixing the distance; sampling at different time points, diluting and then counting the plates; plotting a curve with irradiation time as the horizontal coordinate and the logarithm of survival rate as the vertical coordinate, and calculating the time required for the survival rate to drop to 50% (LT 50 ); a light-proof control is needed to ensure that death is caused only by ultraviolet; The 7-day mortality rate is an evaluation of the virulence of insect pathogenic microorganisms, specifically including: placing Spodoptera exigua 3rd instar larvae in a controlled environment and treating them with Aspergillus wettable powder (the standard concentration is 1 x 10 8 spores / mL) by immersion or spraying, and setting a sterile water control. The feeding conditions (25°C, 70% RH) are standardized, and the number of dead insects is recorded after 7 days. The mortality rate (%) = (the number of deaths in the treatment group - the number of natural deaths in the control group) / the total number in the treatment group x 100%. More than 3 repetitions are needed, and the control group mortality rate is corrected using the Abbott formula; The detection method for the time length of spore preservation activity at 36°C conditions, specifically including: sealing the Aspergillus wettable powder sample in a test tube and placing it in a 36°C constant temperature oven (±0.5°C error) in the dark for preservation; periodically sampling and detecting the number of viable spores by plate counting method. Plotting a decay curve with time points as the horizontal coordinate and the logarithm of viable spore rate as the vertical coordinate, and calculating the half-life of activity (the time when the viable spore rate drops to 50%); at the same time, monitor the humidity change to avoid the influence of drying or condensation on the results. The test results are shown in Table 3 below.
[0074] Table 3 Related properties of Aspergillus wettable powder prepared in Preparation Examples 1 to 10 .
[0075] (Three) Insecticidal activity The insecticidal activity of the Aspergillus wettable powder prepared in Preparation Examples 1 to 10 on Spodoptera exigua is tested by indoor experiments, specifically including: placing Spodoptera exigua 3rd instar larvae in a controlled environment and treating them with a spore suspension (the standard concentration is, for example, 1 x 10 8The spores / mL were treated by immersion or spraying, sterile water was set as control; the feeding conditions (25°C, 70% RH) were standardized, and the number of insect deaths was recorded after 7 days; the mortality rate (%) = (the number of deaths in the treatment group - the number of natural deaths in the control group) / the total number of the treatment group x 100%; it needs to be repeated more than 3 times, and the mortality rate of the control group is corrected by the Abbott formula. Three groups of parallel tests were set respectively, and the test results are shown in Table 4.
[0076] Table 4 Insecticidal activity of Aspergillus wettable powder prepared in preparation examples 1 to 10 on Spodoptera exigua , It can be known from Table 4 that the Aspergillus wettable powder prepared in preparation examples 1 to 10 has high insecticidal activity on Spodoptera exigua.
[0077] Finally, it should be pointed out that the above examples are only used to illustrate the technical solutions of the present application and are not limiting. Although the present application has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present application can be modified or replaced by equivalents without departing from the purpose and scope of the technical solutions of the present application, and they should be covered in the scope of the claims of the present application.
Claims
1. Aspergillus or its conidia are effective in controlling fall armyworm ( Spodoptera frugiperda In its application, Aspergillus has the preservation number CGMCC No.42111.
2. A wettable powder of Aspergillus, characterized by, The Aspergillus wettable powder comprises Aspergillus spore powder, dispersant, wetting agent and carrier, and the preservation number of Aspergillus is CGMCC No.42111.
3. The Aspergillus wettable powder according to claim 2, characterized in that, The Aspergillus wettable powder comprises Aspergillus spore powder, dispersant, wetting agent and carrier, and the preservation number of Aspergillus is CGMCC No.42111.
4. The Aspergillus wettable powder according to claim 3, characterized in that, The Aspergillus wettable powder comprises Aspergillus spore powder, dispersant, wetting agent and carrier, and the preservation number of Aspergillus is CGMCC No.42111.
5. The Aspergillus wettable powder according to any one of claims 2 to 4, characterized in that, The Aspergillus wettable powder comprises Aspergillus spore powder, dispersant, wetting agent and carrier, and the preservation number of Aspergillus is CGMCC No.42111. The Aspergillus wettable powder comprises Aspergillus spore powder, dispersant, wetting agent and carrier, and the preservation number of Aspergillus is CGMCC No.42111. (ii) the number of viable spores of the Aspergillus spore powder is > 1 x 10 9 CFU / g; The Aspergillus wettable powder comprises Aspergillus spore powder, dispersant, wetting agent and carrier, and the preservation number of Aspergillus is CGMCC No.42111. The Aspergillus wettable powder comprises Aspergillus spore powder, dispersant, wetting agent and carrier, and the preservation number of Aspergillus is CGMCC No.42111. The Aspergillus wettable powder further comprises functional adjuvant, and the functional adjuvant is selected from ultraviolet absorber and / or antioxidant.
6. The Aspergillus wettable powder according to any one of claims 2 to 4, characterized in that, 7. The Aspergillus wettable powder according to any one of claims 2 to 4, wherein, The ultraviolet absorber is selected from fluorescein sodium CBS-X and / or humic acid; and / or The antioxidant is selected from one or more combinations of sodium ascorbate, tocopherol or trehalose. The mass percentage of the functional adjuvant is less than or equal to 1%.
8. The Aspergillus wettable powder according to claim 5, characterized in that, The preparation method comprises: mixing Aspergillus spore powder, dispersant, wetting agent and carrier, and crushing to obtain the Aspergillus wettable powder.
9. A process for the preparation of a wettable powder of Aspergillus according to any one of claims 2 to 8, characterized in that, The method comprises:
10. A method of controlling Spodoptera frugiperda in agricultural crops, characterized by applying to the crops a composition according to any one of claims 1 to 9. Spraying the Aspergillus wettable powder according to any one of claims 2 to 8 on the leaf surface of the crop.