Screening method of farnesal and application of farnesal as insect repellant

Abstract

The invention provides a screening method of farnesal and application of the farnesal as an insect repellant, and belongs to the technical field of insect repellants. The farnesaldehyde has a remarkable repelling effect on aphids, and the feeding rate of the aphids to plant leaves can be reduced. Meanwhile, the invention also provides a method for screening aphid-resistant volatile substances, the method can successfully screen aphid-resistant substance components in plants, the method opens up a new direction and possibility for research in the aphid-resistant field, and the method has important positive significance for promoting progress and development of an aphid-resistant technology.

Description

Technical Field

[0001] The present invention relates to the technical field of insect repellents, and particularly to a screening method of farnesal and its application as an insect repellent. Background Art

[0002] Cucumber (Cucumis sativus L.), also known as cucumber and green cucumber, is an annual climbing herbaceous plant of the genus Cucumis in the gourd family and is an important vegetable crop. In recent years, the global cucumber production has been steadily increasing. Cucumbers have a crisp taste and are rich in nutrients, containing various vitamins, minerals, dietary fiber and other nutrients, and are deeply loved by consumers. At the same time, the development of the cucumber industry has also driven the development of related industrial chains, providing more employment opportunities and income sources for farmers. Therefore, cucumbers play an important role in agricultural production and people's lives.

[0003] Aphis gossypii, also known as melon aphid, is an insect of the genus Aphis in the family Aphididae of the order Homoptera in the insect class. Aphis gossypii inserts its stylet into the back of the cotton leaf or the tender head part of the tissue to suck the sap, and the damaged leaves curl backward. During the process of sucking the sap of cotton, a large amount of honeydew is discharged, which not only affects the photosynthesis of cotton, but also easily attracts the parasitism of molds, resulting in diseases such as black mold disease, further aggravating the damage degree of cotton. It seriously harms crops such as cotton, melons and soybeans and is a serious pest that harms plant production.

[0004] Volatile organic compounds (VOCs), when plants are subjected to pests and diseases, mechanical damage or other environmental stresses, will release specific volatile organic compounds (VOCs). These compounds can spread in the air and be sensed by surrounding plants, thereby triggering their defense mechanisms. Such as ethylene, jasmonic acid, etc. The release of these volatile substances can be used to warn neighboring plants and induce a series of defense responses in plants, such as increasing the synthesis of insect-resistant proteins and enhancing the strength of the cell wall, so that they can be prepared in advance and thus improve the insect resistance of plants.

[0005] However, the existing volatile substances at present have high limitations in controlling aphids. Therefore, it is very necessary to obtain a new insect-resistant substance to solve the above problems. Summary of the Invention

[0006] The purpose of the present invention is to provide a screening method of farnesal and its application as an insect repellent. The farnesal has a significant repellent effect on aphids and can reduce the feeding rate of aphids on plant leaves.

[0007] In order to achieve the above invention purpose, the present invention provides the following technical solutions:

[0008] The present invention provides the application of farnesal as an insect repellent.

[0009] Preferably, the object of the insect repellent is aphids.

[0010] More preferably, the aphids are Aphis gossypii.

[0011] The present invention also provides the application of farnesal in the preparation of a product having an aphid repellent effect.

[0012] Preferably, the aphids are Aphis gossypii.

[0013] Preferably, the dosage form of the product includes spray, granule, powder and solution.

[0014] The present invention also provides a method for screening anti-aphid volatile substances, comprising the following steps:

[0015] (1) Select the plant seeds of aphid-resistant varieties and aphid-susceptible varieties respectively, germinate them, and cultivate them to obtain seedlings;

[0016] (2) Select the seedlings that have grown to two leaves and one true leaf, and perform aphid-inoculation and non-aphid-inoculation treatments on the seedlings of aphid-resistant varieties and aphid-susceptible varieties respectively;

[0017] (3) Select the adult aphids on the aphid-inoculated plants, place the starved adult aphids on the plant leaves, select the leaves after the adult aphids have fed for 70 - 75 h, perform metabolome sequencing, and obtain anti-aphid volatile substances;

[0018] The anti-aphid volatile substance is farnesal.

[0019] Preferably, in step (1), the plant is cucumber; the aphid-resistant variety is BN32-7, the aphid-susceptible variety is JY30; the germination temperature is 25 - 30 °C, the germination time is 16 - 48 h; the cultivation temperature is 22 - 30 °C, and the cultivation time is 10 - 18 d.

[0020] Preferably, in step (2), the inoculation quantity of aphids during the aphid-inoculation treatment is 30 - 50 heads / plant.

[0021] Preferably, in step (3), the starvation treatment time is 2 - 3 h; the placement quantity of adult aphids is 40 - 50 heads per leaf.

[0022] The beneficial effects of the present invention compared with the prior art are as follows:

[0023] The present invention provides the application of farnesal as an insect repellent. Farnesal has a significant repellent effect on aphids and can reduce the feeding rate of aphids on plant leaves. The present invention also provides a method for screening anti-aphid volatile substances - farnesal. This method successfully screens out a brand-new anti-aphid substance, and this discovery opens up new directions and possibilities for the research in the field of anti-aphids, and has important positive significance for promoting the progress and development of anti-aphid technology. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required in the embodiments. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0025] Figure 1 It is a physical picture of the cucumber anti-aphid variety BN32-7 with and without aphid infestation treatment groups;

[0026] Figure 2 It is a physical picture of the cucumber aphid-susceptible variety JY30 with and without aphid infestation treatment groups;

[0027] Figure 3 It is a Venn diagram of anti-aphid volatile substances in the cucumber anti-aphid variety BN32-7 with and without aphid infestation treatment groups and the aphid-susceptible variety JY30 with and without aphid infestation treatment groups after sequencing; wherein, Figure 3 BNT in it represents the BN32-7 aphid-infested treatment group, JYT represents the JY30 aphid-infested treatment group, BNWT represents the BN32-7 non-aphid-infested treatment group, and JYWT represents the JY30 non-aphid-infested treatment group;

[0028] Figure 4 It is the farnesal content measured in the cucumber anti-aphid variety BN32-7 with and without aphid infestation groups and the aphid-susceptible variety JY30 with and without aphid infestation groups; wherein, Figure 4 BNWT in it represents the BN32-7 non-aphid-infested treatment group, BNT represents the BN32-7 aphid-infested treatment group, JYWT represents the JY30 non-aphid-infested treatment group, and JYT represents the JY30 aphid-infested treatment group;

[0029] Figure 5 It is the result diagram measured by a four-arm olfactometer in Experimental Example 2. The P value in the figure represents the significance level of the difference, and P < 0.05 indicates a significant difference. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0030] The various exemplary embodiments of the present invention will now be described in detail. This detailed description should not be considered as a limitation of the present invention, but rather as a more detailed description of certain aspects, features, and implementation manners of the present invention.

[0031] It should be understood that the terms described in the present invention are only for describing specific embodiments and are not used to limit the present invention. Additionally, for the numerical ranges in the present invention, it should be understood that each intermediate value between the upper and lower limits of the range is also specifically disclosed. Each intermediate value within any stated value or stated range, as well as each smaller range between any other stated value or intermediate value within the stated range, is also included in the present invention. The upper and lower limits of these smaller ranges may be independently included or excluded from the range.

[0032] Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the art to which the present invention pertains. Although the present invention only describes preferred methods and materials, any methods and materials similar or equivalent to those described herein can also be used in the implementation or testing of the present invention. All documents mentioned in this specification are incorporated by reference to disclose and describe the methods and / or materials related to the said documents. In case of conflict with any incorporated document, the content of this specification shall prevail.

[0033] Without departing from the scope or spirit of the present invention, various improvements and changes can be made to the specific embodiments of the present invention specification, which are obvious to those skilled in the art. Other embodiments obtained from the specification of the present invention are obvious to those skilled in the art. The specification and examples of the present invention are merely exemplary.

[0034] Regarding "comprising", "including", "having", "containing", etc. used herein, they are all open-ended terms, meaning including but not limited to.

[0035] The present invention provides the application of farnesal as an insect repellent.

[0036] In the present invention, the object of insect repellent is preferably aphids, and more preferably Aphis gossypii.

[0037] The present invention also provides the application of farnesal in the preparation of a product having the effect of repelling aphids.

[0038] In the present invention, the aphids are preferably Aphis gossypii; the dosage forms of the product preferably include sprays, granules, powders, and solutions.

[0039] The present invention also provides a method for screening anti-aphid volatile substances to obtain the above-mentioned farnesal, comprising the following steps:

[0040] (1) Select the plant seeds of aphid-resistant varieties and aphid-susceptible varieties respectively, germinate them, and cultivate them to obtain seedlings.

[0041] (2) Select the seedlings that have grown to two leaves and one true leaf, and conduct aphid-inoculation and non-aphid-inoculation treatments on the seedlings of aphid-resistant varieties and aphid-susceptible varieties respectively.

[0042] (3) Select the adult aphids on the aphid-inoculated plants, place the starved adult aphids on the plant leaves, and after 70 - 75 h, select the leaves after aphid sucking, conduct metabolome sequencing, and obtain aphid-resistant volatile substances.

[0043] In the present invention, the plant seeds of aphid-resistant varieties and aphid-susceptible varieties are selected respectively, germinated, and cultivated to obtain seedlings. The specific analysis / explanation is as follows:

[0044] In the present invention, the plant seeds preferably show plump grains; the plant is preferably cucumber; the aphid-resistant variety is preferably BN32 - 7, and the aphid-susceptible variety is preferably JY30; the method of germinating is preferably to place the plant seeds on the moist paper towels in a petri dish and then place them in a constant-temperature incubator for germination; the temperature for germination is preferably 25 - 30 °C, more preferably 26 - 29 °C, still more preferably 27 - 28 °C; the time for germination is preferably 16 - 48 h, more preferably 20 - 40 h, still more preferably 25 - 35 h, and even more preferably 30 h; before cultivation, the germinated seeds are preferably placed in a cultivation pot for 14 - 16 d to obtain pre-treated seedlings, more preferably 15 d; during cultivation, the pre-treated seedlings are preferably placed in an artificial climate incubator for cultivation; the temperature for cultivation is preferably 22 - 30 °C, more preferably 24 - 29 °C, still more preferably 25 - 28 °C; the time for cultivation is preferably 10 - 18 d, more preferably 14 - 16 d, still more preferably 15 d.

[0045] In the present invention, the seedlings that have grown to two leaves and one true leaf are selected, and aphid-inoculation and non-aphid-inoculation treatments are conducted on the seedlings of aphid-resistant varieties and aphid-susceptible varieties respectively. The specific analysis / explanation is as follows:

[0046] In the present invention, the inoculation quantity of aphids during the aphid-inoculation treatment is preferably 30 - 50 heads / plant, more preferably 35 - 45 heads / plant, still more preferably 40 heads / plant; the basic morphology of the seedlings is preferably strong growth and health; the aphid-inoculation treatment and non-aphid-inoculation treatment of the aphid-resistant variety are preferably both set with 3 replicates; the aphid-inoculation treatment and non-aphid-inoculation treatment of the aphid-susceptible variety are preferably both set with 3 replicates.

[0047] In the present invention, adult aphids on the plants treated with aphid inoculation are selected, and the starved adult aphids are placed on the plant leaves. After 70 - 75 h, the leaves punctured and sucked by the adult aphids are selected for metabolome sequencing to obtain anti - aphid volatile substances. The specific analysis / description is as follows:

[0048] In the present invention, the adult aphids are preferably healthy and vigorous; the starvation treatment time is preferably 2 - 3 h, more preferably 2.2 - 2.8 h, and even more preferably 2.4 - 2.6 h; the number of adult aphids placed is preferably 40 - 50 per leaf, more preferably 42 - 48 per leaf, and even more preferably 44 - 46 per leaf; the time for selecting the leaves punctured and sucked by the adult aphids is preferably 72 - 74 h, more preferably 73 h; the anti - aphid volatile substance is preferably farnesal.

[0049] Example 1

[0050] A method for screening anti - aphid volatile substances comprises the following steps:

[0051] (1) Cucumber seeds of the aphid - resistant variety BN32 - 7 and the aphid - susceptible variety JY30 with plump grains (from the cucumber research group of Yangzhou University) are respectively selected, placed on the moist paper towels in a petri dish, and then placed in a constant - temperature incubator at 28 °C for 24 h of germination treatment. The germinated seeds are placed in a cultivation pot for 15 d of cultivation to obtain pre - treated seedlings, and the pre - treated seedlings are placed in an artificial climate incubator at 24 °C for 14 d of cultivation to obtain seedlings;

[0052] (2) Seedlings that have grown to two leaves and one true leaf and are strong and healthy are selected, and an aphid - resistant variety inoculated treatment group, an aphid - resistant variety non - inoculated treatment group, an aphid - susceptible variety inoculated treatment group, and an aphid - susceptible variety non - inoculated treatment group are set up, with 3 replicates in each group;

[0053] (3) Healthy and vigorous adult aphids on the plants treated with aphid inoculation are selected, starved for 2 h, and the active adult aphids are selected with a brush and placed on the cucumber leaves at a ratio of 40 per leaf. After 72 h, the aphids are first picked away with a brush, and then the leaf area punctured and sucked by the adult aphids is selected for metabolome sequencing to obtain anti - aphid volatile substances.

[0054] Example 2

[0055] A method for screening anti - aphid volatile substances comprises the following steps:

[0056] (1) Select cucumber seeds of the aphid-resistant variety BN32-7 and the aphid-susceptible variety JY30 with plump grains respectively, place them on the moist paper towels in a petri dish, and then place them in a constant temperature incubator at 25 °C for germination treatment for 48 h. Place the germinated seeds in a cultivation pot for cultivation for 16 d to obtain pre-treated seedlings, and place the pre-treated seedlings in an artificial climate incubator at 22 °C for cultivation for 18 d to obtain seedlings;

[0057] (2) Select seedlings that have grown to two leaves and one true leaf and are strong and healthy. Set up an aphid-resistant variety insect-infested treatment group, an aphid-resistant variety non-insect-infested treatment group, an aphid-susceptible variety insect-infested treatment group, and an aphid-susceptible variety non-insect-infested treatment group, with 3 replicates in each group;

[0058] (3) Select healthy and viable adult aphids on the insect-infested plants, subject them to starvation treatment for 3 h, pick viable adult aphids with a brush, and place them on cucumber leaves at a ratio of 50 per leaf. After 70 h, first pick away the aphids with a brush, and then select the leaf area after adult aphid sucking, and perform metabolome sequencing on it to obtain anti-aphid volatile substances.

[0059] Example 3

[0060] A method for screening anti-aphid volatile substances is as follows:

[0061] (1) Select cucumber seeds of the aphid-resistant variety BN32-7 and the aphid-susceptible variety JY30 with plump grains respectively, place them on the moist paper towels in a petri dish, and then place them in a constant temperature incubator at 30 °C for germination treatment for 16 h. Place the germinated seeds in a cultivation pot for cultivation for 14 d to obtain pre-treated seedlings, and place the pre-treated seedlings in an artificial climate incubator at 30 °C for cultivation for 10 d to obtain seedlings;

[0062] (2) Select seedlings that have grown to two leaves and one true leaf and are strong and healthy. Set up an aphid-resistant variety insect-infested treatment group, an aphid-resistant variety non-insect-infested treatment group, an aphid-susceptible variety insect-infested treatment group, and an aphid-susceptible variety non-insect-infested treatment group, with 3 replicates in each group;

[0063] (3) Select healthy and viable adult aphids on the insect-infested plants, subject them to starvation treatment for 2.5 h, pick viable adult aphids with a brush, and place them on cucumber leaves at a ratio of 45 per leaf. After 75 h, first pick away the aphids with a brush, and then select the leaf area after adult aphid sucking, and perform metabolome sequencing on it to obtain anti-aphid volatile substances.

[0064] Test Example 1

[0065] Screen the anti-aphid volatile substances on cucumbers according to the method in Example 1.

[0066] The metabolome sequencing results are as Figure 3 and Figure 4 shown.

[0067] The results showed that there were 17 substances with significant differences before and after insect inoculation in resistant and susceptible varieties. Among them, farnesal had the most significant difference between resistant and susceptible varieties, and was significantly up-regulated after insect inoculation in the aphid-susceptible variety JY30.

[0068] Experimental Example 2

[0069] The anti-aphid property of farnesal was identified using a four-arm olfactometer. Three experiments were set up, with 30 groups in each experiment, 10 minutes for each group, and 10 aphids in each group. Before the experiment, sterile filter papers of the same size were placed in the odor source bottles of the four arms. Using a pipette, 20 μl of farnesal, hexane, and α-farnesene stock solutions (all purchased from Shanghai Aladdin Biochemical Technology Co., Ltd.) were respectively pipetted onto the sterile filter papers at three randomly selected arms; no substance was added to the sterile filter paper at the remaining arm, which served as a blank control group. After the above operations, adult cucumber aphids were placed in the middle part of the olfactometer.

[0070] The results were as Figure 5 shown.

[0071] The results showed that compared with the odor source bottles of the blank control groups with hexane added and no substance added, the aphids chose the odor source bottles with farnesal added less frequently. Therefore, farnesal, as a differential metabolite, has a significant repellent effect on aphids.

[0072] It can be seen from the above examples that the present invention provides the application of farnesal as an insect repellent. The farnesal has a significant repellent effect on aphids, and the method for screening anti-aphid volatile substances provided by the present invention can successfully screen out volatile substances with anti-aphid effects.

[0073] The above are only the preferred embodiments of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the principle of the present invention, several improvements and modifications can be made, and these improvements and modifications should also be regarded as the protection scope of the present invention.

Claims

1. Use of farnesal as an insect repellent.

2. The application according to claim 1, characterized in that The object of the insect repellent is aphids.

3. The application according to claim 2, wherein The aphids are Aphis gossypii.

4. Use of farnesal in the preparation of a product having an aphid-repellent effect.

5. The application according to claim 4, wherein The aphids are Aphis gossypii.

6. The application according to claim 4 or 5, characterized in that, The dosage forms of the product include sprays, granules, powders and solutions.

7. A method for screening anti-aphid volatile substances, characterized in that, It includes the following steps: (1) Select the plant seeds of the aphid-resistant variety and the aphid-susceptible variety respectively, germinate, culture to obtain seedlings; (2) Select the seedlings that have grown to two leaves and one true leaf, and perform insect inoculation and non-insect inoculation treatments on the seedlings of the aphid-resistant variety and the aphid-susceptible variety respectively; (3) Select the adult aphids on the insect-inoculated plants, place the starved adult aphids on the plant leaves, and select the leaves after the adult aphids have fed 70 - 75h later, perform metabolome sequencing to obtain aphid-resistant volatile substances; The aphid-resistant volatile substance is farnesal.

8. The method according to claim 7, wherein In step (1), the plant is cucumber; the aphid-resistant variety is BN32-7, the aphid-susceptible variety is JY30; the germination temperature is 25 - 30°C, the germination time is 16 - 48h; the culture temperature is 22 - 30°C, the culture time is 10 - 18d.

9. The method according to claim 7, wherein In step (2), the inoculation quantity of aphids during the insect inoculation treatment is 30 - 50 heads / plant.

10. The method according to claim 7, characterized in that, In step (3), the starvation treatment time is 2 - 3h; the placement quantity of adult aphids is 40 - 50 heads per leaf.

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