Application method and application of fennel volatile oil in plant growth promotion

Abstract

The invention belongs to the technical field of plant growth regulators, and discloses an application method and application of fennel volatile oil in promoting plant growth, the application method of the fennel volatile oil in promoting plant growth comprises the following steps: step 1, putting 1kg of fennel dry product and distilled water into a 10L round-bottom flask according to a ratio of 1: 8, and stirring uniformly; after soaking for 9h, distilling for 7-10h by adopting a steam distillation method; and step 2, removing moisture from the collected fennel volatile oil by using anhydrous sodium sulfate, storing in a brown bottle, and placing in a refrigerator at-20 DEG C for later use. The fennel volatile oil is found to be used as a non-hormone small molecule and can promote plant growth; the fennel volatile oil is found to promote the increase of the contents of auxin, ethylene and gibberellin; after the fennel volatile oil is prepared into the nano-emulsion, plant growth can be promoted through leaf spraying and root irrigation.

Description

Technical Field

[0001] The invention belongs to the technical field of plant growth regulators, and in particular relates to an application method and use of fennel volatile oil in promoting plant growth. Background Art

[0002] The root system is the main organ for plants to absorb water and nutrients. A good root system architecture directly affects rhizosphere processes and interactions, and is essential for plant growth, development, yield, quality, economic value, and coping with different stress conditions. The growth and development of the root system and changes in the root system architecture are regulated by complex endogenous signal pathways and are affected by many biological and abiotic factors. Regulating the root system architecture and promoting the development of lateral roots and root hairs can enhance plant growth and rhizosphere nutrient absorption and improve fertilizer utilization.

[0003] Plant secondary metabolites play a vital "ecological role", but their potential in the green development of agriculture has not been fully utilized. Fennel (Foeniculum vulgare Mill) volatile oil is widely available and inexpensive, and its main components include 4-allylphenyl ether, d-limonene, etc. Some studies have studied the chemical composition of fennel volatile oil from other perspectives such as the development and manufacture of flavors and fragrances, antioxidants, bioherbicides, and fungicides, but there is no research on the effect of fennel volatile oil on plant growth.

[0004] Through the above analysis, the problems and defects of the prior art are as follows:

[0005] There is no research on the effects of fennel essential oil on plant growth. Summary of the invention

[0006] In view of the problems existing in the prior art, the present invention provides an application method and use of fennel volatile oil in promoting plant growth.

[0007] The present invention is achieved in that a method for applying fennel volatile oil in promoting plant growth comprises:

[0008] Step 1: put 1 kg of dried fennel and distilled water in a 10L round-bottom flask at a ratio of 1:8, soak for 9 hours, and then distill for 7-10 hours using steam distillation;

[0009] Step 2: After removing moisture from the collected fennel volatile oil with anhydrous sodium sulfate, store it in a brown bottle and place it in a refrigerator at 20° C. for later use.

[0010] Furthermore, the volatile oil is used in promoting plant growth, wherein the plants include the model plant Arabidopsis thaliana and the crops pepper and rice, and the volatile oil is prepared by steam distillation.

[0011] Furthermore, the volatile oil acts on the plant in the form of gas volatilization, and the volatile oil is adsorbed by filter paper in the laboratory and placed in a culture dish.

[0012] Furthermore, the volatile oil is applied in the field using fennel volatile oil nanoemulsion, the volatile oil surfactant Tween 80 and a co-surfactant are used as solvent and dispersant, and the co-surfactant is anhydrous ethanol.

[0013] In combination with the above technical solutions and the technical problems solved, the advantages and positive effects of the technical solutions to be protected by the present invention are as follows:

[0014] First, the present invention discovered that fennel volatile oil, as a non-hormone small molecule, can promote plant growth;

[0015] It was found that fennel volatile oil promotes the increase of plant auxin, ethylene, and gibberellin content; after fennel volatile oil is prepared into nanoemulsion, it can promote plant growth through leaf spraying and root irrigation.

[0016] In the field of agriculture, the promotion of plant growth has always been a hot topic of research. This method introduces an innovative technology for promoting plant growth using fennel volatile oil. First, the volatile oil is extracted by the steam distillation method provided by the present invention, and the fennel volatile oil is successfully extracted. This step not only ensures the efficient extraction of the volatile oil, but also retains its active ingredients.

[0017] The extracted volatile oil is removed by anhydrous sodium sulfate, stored in a brown bottle, and placed in a refrigerator at 20°C for future use. This storage method ensures the quality and stability of the volatile oil, providing a reliable material basis for subsequent agricultural applications. In addition, the volatile oil mentioned in this method is suitable for a variety of plants, including the model plant Arabidopsis thaliana and important crops such as pepper and rice, showing its wide applicability.

[0018] Under laboratory conditions, volatile oil acts on plants in the form of gaseous volatilization. The volatile oil is adsorbed on filter paper and placed in a petri dish, achieving direct contact between the volatile oil and the plant. This application method is simple and effective, and it is easy to control the concentration and action time of the volatile oil, which provides convenience for studying the role of volatile oil in promoting plant growth.

[0019] In order to apply this method to field practice, we used fennel volatile oil nanoemulsion as a carrier, mixed the volatile oil with the surfactant Tween 80 and the co-surfactant anhydrous ethanol to prepare a nanoemulsion that is easy to apply. This emulsion not only improves the stability and dispersibility of the volatile oil, but also enhances its adhesion and permeability on plant leaves, thereby improving the effect of the volatile oil on plant growth. This technological advancement provides strong technical support for the widespread application of fennel volatile oil in agricultural production.

[0020] Third, as auxiliary evidence of the inventiveness of the claims of the present invention, it is also reflected in the following important aspects:

[0021] (1) The expected benefits and commercial value of the technical solution of the present invention after transformation are as follows: Expected benefits: 1. Increased production and income: As a natural product, volatile oil has the potential to be developed into a green plant growth regulator or a pollution-free fertilizer additive, in order to achieve the effect of increased production and income. 2. Reduce environmental pollution and the residue of harmful substances in plants: After the development and utilization of fennel volatile oil, the use of harmful plant growth regulators such as bulking agents on the market can be reduced, environmental pollution can be reduced, and the green, innovative and sustainable development of agriculture can be accelerated.

[0022] Commercial value: 1. Market potential: With people's increasing attention to environmental protection and food safety, the demand for natural and environmentally friendly plant growth regulators is gradually increasing. Fennel is a plant that is both medicinal and edible. As a natural plant extract, fennel volatile oil has the effect of regulating plant growth. It can be developed as a natural plant growth regulator or as a fertilizer additive to increase plant yields. It has broad market prospects and potential. 2. Industrial chain extension: The use of fennel volatile oil as a plant growth regulator can drive the development of related industrial chains, such as the planting, processing, and sales of fennel, forming a complete industrial chain and contributing to local economic development. 3. Technological innovation: The transformation of the technical solution of fennel volatile oil as a plant growth regulator is an important direction of agricultural technological innovation. The successful application of this technology will help improve agricultural production efficiency and quality and promote agricultural development.

[0023] (2) The technical solution of the present invention fills the technical gap in the industry at home and abroad: Development of natural plant growth regulators: Currently, most of the plant growth regulators on the market are artificially synthesized, while fennel volatile oil is a plant growth regulator from a natural source. Its development and application fills the technical gap of plant growth regulators from a natural source.

[0024] Multifunctional application of fennel volatile oil in agriculture: Although fennel volatile oil has certain applications in traditional medicine, cosmetics and other fields, its use as a plant growth regulator in the agricultural field is relatively rare. The proposal of this technical solution fills the application gap of fennel volatile oil in promoting plant growth, increasing yield, improving quality and so on.

[0025] Innovation of environmentally friendly agricultural inputs: With the improvement of environmental awareness, agricultural production has higher and higher requirements for the environmental friendliness of inputs. As a natural and pollution-free agricultural input, the development and application of fennel volatile oil meets the innovative needs of environmentally friendly agricultural inputs and fills the technical gap in this field.

[0026] (3) The technical solution of the present invention solves a technical problem that people have been eager to solve but have never been able to solve successfully: in the Chinese medicinal material planting industry, some Chinese medicinal materials such as Paris polyphylla and Panax notoginseng grow slowly and take a long time to grow. If they can be applied to Chinese medicinal material planting, the growth rate of medicinal materials can be accelerated and the planting period of medicinal materials can be shortened, which will promote the innovative development of the Chinese medicinal material industry. In crop planting, the use of hormone pesticides can be reduced or avoided, pesticide residues can be reduced, and crop quality can be improved.

[0027] (4) The technical solution of the present invention overcomes technical prejudice: plant volatile oil, as a volatile substance of the plant itself, is unstable and volatile, which limits its use. However, the technology of making volatile oil into nanoemulsion overcomes the technical prejudice of low utilization rate of volatile oil, greatly reduces its volatility, improves stability, and is conducive to storage and transportation. At the same time, the adhesion, dispersibility and permeability of volatile oil on plant leaves are further improved, and it can also be used by root irrigation. Various ways of use can promote plant growth. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 The present invention is a flowchart of a method for applying fennel volatile oil in promoting plant growth provided by an embodiment of the present invention.

[0029] Figure 2 This is a graph showing the effect of fennel essential oil provided in an embodiment of the present invention on the growth of Arabidopsis thaliana.

[0030] Figure 3 This is a graph showing the effect of fennel volatile oil on the content of Arabidopsis hormones (auxin, ethylene, gibberellin) provided in an embodiment of the present invention.

[0031] Figure 4 It is the KEGG enrichment analysis of the common differential genes between the low concentration fennel volatile oil (LC) and the high concentration fennel volatile oil (HC) provided in the embodiment of the present invention, showing the top 10 enriched pathway maps.

[0032] Figure 5This is a graph showing the effect of root irrigation with the fennel volatile oil nanoemulsion provided in an embodiment of the present invention on the growth of pepper.

[0033] Figure 6 This is a diagram showing the effect of spraying the fennel volatile oil nanoemulsion on the growth of pepper (A) and rice (B) provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0034] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0035] like Figure 1 As shown, a method for applying fennel volatile oil in promoting plant growth provided by an embodiment of the present invention comprises the following steps:

[0036] S101, put 1 kg of dried fennel and distilled water in a ratio of 1:8 into a 10 L round-bottom flask, soak for 9 hours, and then distill for 7-10 hours using steam distillation;

[0037] S102, the collected fennel volatile oil is dehydrated with anhydrous sodium sulfate and stored in a brown bottle, and placed in a -20°C refrigerator for later use.

[0038] The embodiment of the present invention provides a method for applying fennel volatile oil in promoting plant growth. Through a series of precise steps and treatments, high-purity fennel volatile oil is finally obtained, ensuring its effectiveness and stability in promoting plant growth.

[0039] Step S101: Extraction of fennel essential oil

[0040] 1) Raw materials preparation:

[0041] Choose high-quality dried fennel 1kg to ensure its purity to ensure the effectiveness of the extracted volatile oil.

[0042] 2) Soaking:

[0043] Place dried fennel and distilled water in a 1:8 ratio (1 kg dried fennel with 8 L distilled water) into a 10 L round-bottom flask.

[0044] Soak the dried fennel in distilled water for 9 hours to allow the active ingredients to fully dissolve and leach out, preparing for subsequent distillation extraction.

[0045] 3) Steam distillation:

[0046] After the soaking is completed, the steam distillation device is started and the distillation process is carried out for 7-10 hours.

[0047] During the distillation process, water vapor is heated to release the volatile components in fennel. The vapor carrying these components is cooled through a condenser and condensed into a liquid, which contains volatile oils and a small amount of water.

[0048] Step S102: Processing and storage

[0049] 4) Volatile oil collection and dehydration:

[0050] The collected distillate is placed in a separatory funnel for separation to obtain preliminary fennel volatile oil.

[0051] The initially obtained volatile oil is dehydrated with anhydrous sodium sulfate. As a desiccant, anhydrous sodium sulfate can absorb the water in the volatile oil and make the volatile oil more pure.

[0052] 5) Storage of volatile oil:

[0053] Transfer the dehydrated fennel essential oil to a brown bottle. The brown bottle can prevent the essential oil from being affected by light and oxidized or degraded, maintaining its stability and the activity of the active ingredients.

[0054] Finally, place the brown bottle in a refrigerator at -20℃. The low temperature environment can further prevent the oxidation and volatilization of the volatile oil, ensuring its quality in subsequent use.

[0055] Application effect:

[0056] 1. Promotes Plant Growth:

[0057] The extracted and processed fennel volatile oil contains a variety of effective ingredients that promote plant growth, such as anethole, aniseone, etc. These ingredients can improve the disease resistance and growth rate of plants by regulating the physiological activities of plants.

[0058] In practical applications, diluting fennel volatile oil in a certain proportion and spraying it on the surface of plants or applying it to the soil can effectively promote the growth and health of plants.

[0059] Through precise soaking, distillation, dehydration and preservation steps, the application method of fennel volatile oil in promoting plant growth provided by the embodiment of the present invention can effectively extract and preserve the effective ingredients in fennel, ensuring its high efficiency and stability in application. This method not only improves the growth rate and health of plants, but also provides a natural and environmentally friendly plant growth promoter.

[0060] Example 1

[0061] 1) Raw materials preparation:

[0062] Choose high-quality dried cumin 1kg and ensure the quality and purity of the dried product.

[0063] 2) Soaking:

[0064] Place dried fennel and 8 L of distilled water in a 10 L round-bottom flask at a ratio of 1:8.

[0065] Soak at room temperature for 9 hours to allow the active ingredients in fennel to fully dissolve and extract.

[0066] 3) Steam distillation:

[0067] After the soaking is completed, the steam distillation device is started and the distillation process is carried out for 7 hours.

[0068] During the distillation process, the distillation temperature and pressure are controlled so that the volatile components in fennel evaporate with the steam and condense into liquid. The collected liquid contains volatile oil and a small amount of water.

[0069] 4) Volatile oil collection and dehydration:

[0070] Use a separatory funnel to separate the distilled liquid and collect the preliminary fennel volatile oil.

[0071] The collected volatile oil is dehydrated with anhydrous sodium sulfate to ensure that the water in the volatile oil is completely removed.

[0072] 5) Storage of volatile oil:

[0073] The dehydrated fennel essential oil was transferred to a brown bottle to prevent light from affecting the quality of the essential oil.

[0074] Store the brown bottle in a refrigerator at -20°C to ensure that the volatile oil remains stable in a low temperature environment.

[0075] Plant Growth Promotion:

[0076] After diluting the extracted volatile oil to an appropriate concentration, spray it on the leaves of crops such as tomatoes and cucumbers once a week.

[0077] Observe and record the growth of plants, including plant height, number of leaves, and leaf color changes.

[0078] Example 2

[0079] 1) Raw materials preparation:

[0080] Choose 1kg of high-quality dried fennel to ensure that the dried product is free of impurities and has stable ingredients.

[0081] 2) Soaking:

[0082] Place 1 kg of dried fennel and 8 L of distilled water into a 10 L round-bottom flask and soak for 9 hours.

[0083] During this period, the mixture is stirred regularly to ensure that the active ingredients are fully leached.

[0084] 3) Steam distillation:

[0085] After the soaking is completed, the steam distillation device is started and the distillation process is carried out for 10 hours.

[0086] The temperature and pressure of the distillation apparatus are controlled so that the volatile components in the fennel evaporate together with the steam and are condensed into liquid through the condenser.

[0087] 4) Volatile oil collection and dehydration:

[0088] The distilled liquid is separated by a separatory funnel to obtain preliminary fennel volatile oil.

[0089] Dehydration treatment was performed using anhydrous sodium sulfate to remove residual water in the volatile oil.

[0090] 5) Storage of volatile oil:

[0091] Transfer the dehydrated volatile oil to a brown bottle to avoid oxidation caused by light.

[0092] The brown bottle was stored in a refrigerator at -20°C to ensure the long-term stability and activity of the volatile oil.

[0093] Plant growth promotion: Dilute the extracted fennel essential oil to an appropriate concentration and add it to irrigation water. Water strawberry and pepper plants regularly, twice a week.

[0094] Record plant performance, including growth rate, fruit quantity and quality, and plant disease resistance.

[0095] Through these two specific examples, we can see the significant effect of the fennel volatile oil provided by the present invention on promoting plant growth. Different preparation and application methods can be flexibly adjusted according to actual needs to achieve the best plant growth promotion effect.

[0096] The embodiment of the present invention provides an application of volatile oil in promoting plant growth, wherein the plants include the model plant Arabidopsis thaliana and the crops pepper and rice, and the volatile oil is prepared by steam distillation.

[0097] The volatile oil provided in the embodiment of the present invention acts on the plant in the form of gas volatilization. The volatile oil is adsorbed by filter paper in the laboratory and placed in a culture dish.

[0098] The volatile oil provided in the embodiment of the present invention is applied in the field using a fennel volatile oil nanoemulsion, wherein the volatile oil surfactant Tween 80 and the co-surfactant anhydrous ethanol are used as solvent and dispersant;

[0099] The working principle of the application method of fennel essential oil in promoting plant growth is mainly based on the following aspects:

[0100] 1. Extraction of volatile oil:

[0101] The volatile oil is extracted by mixing dried fennel with distilled water in a specific ratio and soaking it in water, and then using steam distillation to extract the volatile oil. The steam distillation method can simulate the steam distillation process in the natural environment and effectively retain the active ingredients in the volatile oil.

[0102] The extracted volatile oil contains a variety of biologically active compounds, which play an important role in promoting plant growth.

[0103] 2. Storage and stability of volatile oils:

[0104] After the volatile oil is dehydrated by anhydrous sodium sulfate, it is stored in a brown bottle and placed in a refrigerator at -20°C. This storage method can prevent the volatile oil from oxidation and deterioration, and maintain its stability and activity.

[0105] 3. Mechanism of action of volatile oils in plant growth:

[0106] Volatile oils act on plants in the form of gaseous volatilization and enter the plant body through the stomata or epidermis of the plant leaves.

[0107] In plants, the active ingredients in volatile oils can activate the plant's growth and metabolic pathways, promote the plant's photosynthesis, respiration and other physiological processes, thereby accelerating the plant's growth rate and increasing yield.

[0108] 4. Field application and nanoemulsion technology:

[0109] When applied in the field, fennel volatile oil nanoemulsion is used as a carrier, and the volatile oil is mixed with a surfactant Tween 80 and a co-surfactant anhydrous ethanol to prepare a nanoemulsion.

[0110] Nanoemulsion technology can improve the adhesion and permeability of volatile oils on plant leaves, making them easier to be absorbed and utilized by plants.

[0111] As a non-ionic hydrophilic surfactant, Tween80 can reduce the interfacial tension between volatile oil and water, making it better dispersed in water to form a stable emulsion.

[0112] Anhydrous ethanol as a co-surfactant can further improve the stability and dispersibility of the emulsion and enhance the adhesion and permeability of volatile oils on plant leaves.

[0113] In summary, the application method of fennel volatile oil in promoting plant growth is to extract volatile oil by steam distillation, and through preservation, laboratory and field application, the active ingredients in the volatile oil can fully play its role in promoting plant growth. The application of nanoemulsion technology further improves the adhesion and permeability of volatile oil on plant leaves, thereby improving the effect of volatile oil on promoting plant growth.

[0114] Example 1: Extraction of fennel volatile oil

[0115] Put 1 kg of dried fennel and distilled water in a ratio of 1:8 into a 10L round-bottom flask, soak for 9 hours, and then distill for 7-10 hours using steam distillation. After removing moisture from the collected fennel volatile oil with anhydrous sodium sulfate, store it in a brown bottle and place it in a -20°C refrigerator for later use.

[0116] Example 2: Treatment of Arabidopsis thaliana with fennel essential oil

[0117] The fennel essential oil emulsions with concentrations of 0.5 mg / mL and 1 mg / mL were prepared with a 2DMSOT aqueous solution (1 / 1000 Tween 80 and 20 / 1000 DMSO (dimethyl sulfoxide)), and then filtered with a 0.22 μm microporous filter membrane. The 2DMSOT aqueous solution was used as the control solution.

[0118] Arabidopsis seeds were placed in a 4°C refrigerator for "vernalization" for 3 days, and then placed in a 1.5mL EP tube for surface disinfection. The disinfected seeds were placed on 1 / 8MS basal medium (Murashige and Skoog basal salt mixture, catalog number: M5524) for germination and growth. The plate was placed vertically at 90°C, allowing the roots to grow downward along the agar surface. At 22°C, the light intensity was 130μmol·m-2·s-1, and the light was 16h and the dark was 8h for 4 days. After germination, filter paper pieces with a diameter of 5mm were placed on the lid of the dish at equal distances. Each filter paper piece was added with 7μL of volatile oil and control solution. Each treatment was repeated 57 times. The biomass of Arabidopsis was measured after culturing for 20 days at 22°C with 16h of light and 8h of darkness.

[0119] Example 3: Preparation of fennel volatile oil nanoemulsion

[0120] Step 1: Weigh 80 g of Tween 80 and 40 g of anhydrous ethanol into a 250 mL conical flask, place it on a magnetic stirrer and stir for 5 min, then ultrasonicate it in an ice bath for 20 min.

[0121] Step 2: Prepare emulsion (taking 18g and concentration of 111mg / mL as an example)

[0122] Weigh 8 g of the above-mentioned mixed surfactant with Km=2 (Km is the mass ratio of Tween 80 to anhydrous ethanol) into a 50 mL conical flask, add 2 g of volatile oil, seal with plastic wrap, place on a magnetic stirrer and stir for 5 min, then place in an ultrasonic machine for ice bath ultrasonication for 20 min, then let stand for 15 min, place the conical flask on a magnetic stirrer and add water while stirring, slowly add, add 8 g of water in total. After adding water, continue stirring for 5 min, then place in an ultrasonic machine for ice bath ultrasonication for 20 min, and the nanoemulsion is prepared.

[0123] Example 4: Root irrigation of fennel volatile oil nanoemulsion on peppers

[0124] Pepper seedlings of uniform size were selected for transplanting. Five days later, roots were irrigated with 0.5 mg / mL fennel volatile oil nanoemulsion once every 10 days, for a total of two times. Plant height, stem diameter, biomass, and root weight of the peppers were counted.

[0125] Example 5: Spraying rice with fennel volatile oil nanoemulsion

[0126] Rice seedlings of uniform size were selected for transplanting. Five days later, 0.5 mg / mL fennel volatile oil nanoemulsion was sprayed on the leaves until water dripped from the leaves. The plant height, stem diameter, biomass, and root weight of the rice were counted.

[0127] Figure 2 Effects of fennel essential oil on the growth of Arabidopsis. (A) Growth of Arabidopsis under different concentrations of essential oil. Arabidopsis seedlings were grown on vertically oriented 1 / 8MS agar plates for 20 days under different concentrations of fennel essential oil. The three treatments were: CK0, LC0.5 mg / mL and HC1.0 mg / mL. (B) Comparison of leaf size between CK, LC and HC. (C) Effects of fennel essential oil on Arabidopsis biomass, in order of main root length, lateral root number, lateral root length and fresh weight.

[0128] After 20 days of cultivation, Figure 2As shown in A and B, compared with the control, both concentrations of fennel essential oil significantly promoted the taproot length, lateral root number, lateral root length, and fresh weight of Arabidopsis plants. The taproot length, lateral root number, lateral root length, and fresh weight of the HC group increased by 1.45 times, 1.59 times, 1.61 times, and 1.36 times, respectively, compared with the control group. The promoting effect on the underground part was significant. It also promoted the growth of the aboveground part (leaves) of Arabidopsis (shown in 1C). The above experimental results show that both concentrations of fennel essential oil can promote the growth of Arabidopsis plant leaves and the biomass of the underground part, especially significantly promoting the growth and development of the Arabidopsis root system.

[0129] Figure 3 Effects of fennel essential oil on the content of hormones (auxin, ethylene, gibberellin) in Arabidopsis thaliana. (Experimental data are expressed as the mean ± standard error of 3 biological replicates, *, 0.01 <P<0.05;,P<0.01)

[0130] Hormones are important plant growth regulators that play an important regulatory role in plant growth and development and stress response. In order to explore whether fennel volatile oil treatment would affect hormones in Arabidopsis, the contents of auxin, ethylene, and gibberellin in Arabidopsis treated with fennel volatile oil were measured. The results showed that the contents of auxin, ethylene, and gibberellin increased significantly, increasing by 1.25 times, 1.22 times, and 1.14 times, respectively ( Figure 2 C). Auxin, ethylene and gibberellin play an important role in the development of plant roots and shoots, among which auxin is a key regulatory factor in lateral root development and root hair development. Studies have shown that auxin plays a major regulatory role in plant lateral root formation, hypocotyl elongation and vascular tissue differentiation, and the results of the study showed that the role of fennel volatile oil in promoting the root development of Arabidopsis is similar to the role of auxin in plants. Therefore, it is speculated that the effect of fennel volatile oil on promoting the root growth and development of wild-type Arabidopsis plants is mainly mediated by auxin.

[0131] Figure 4 KEGG enrichment analysis of differentially expressed genes between low-concentration fennel volatile oil (LC) and high-concentration fennel volatile oil (HC) shows the top 10 enriched pathways. The y-axis represents the pathway category, the x-axis represents the enrichment degree of the pathway, the shape size represents the number of differentially expressed genes, and the color represents the enrichment degree. The redder the color, the more significant the enrichment.

[0132] In order to explore how fennel volatile oil regulates the transcription level of plant hormones and thus promotes the growth of Arabidopsis, RNAseq analysis and sequencing were performed, and KEGG functional annotation analysis was performed on all DEGs. KEGG pathway ( Figure 4) showed that in the CK vs. LC and CK vs. HC groups, metabolic processes were significantly enriched, followed by plant hormone signaling, phenylpropanoid biosynthesis and other pathways. Hormones, as important plant growth regulators, play an important regulatory role in plant growth and development and stress response. KEGG results showed that fennel volatile oil can promote the growth and development of Arabidopsis by upregulating the expression of genes related to plant hormone signaling.

[0133] Figure 5 Effect of root irrigation with fennel volatile oil nanoemulsion on pepper growth. The blank group was irrigated with the same amount of water, and the treatment group was irrigated with 0.5 mg / mL fennel volatile oil nanoemulsion.

[0134] like Figure 5 As shown, compared with the blank group, the root irrigation treatment group of 0.5 mg / mL fennel volatile oil nanoemulsion had a significant promoting effect on the plant height, stem diameter, biomass and root weight of pepper plants. The plant height, stem diameter, biomass and root weight of the HC group increased by 1.25 times, 1.51 times, 1.61 times and 1.44 times respectively compared with the blank group. The promoting effect on both the aboveground and underground parts was very significant. In summary, the experimental results show that fennel volatile oil nanoemulsion can promote the growth of pepper plant leaves and roots, and increase the accumulation of biomass.

[0135] Figure 6 Effects of fennel volatile oil nanoemulsion spraying on leaves on the growth of pepper (A) and rice (B). The blank group was sprayed with an equal amount of water, and the treatment group was sprayed with 0.5 mg / mL fennel volatile oil nanoemulsion.

[0136] like Figure 6 As shown, compared with the blank group, the 0.5 mg / mL fennel volatile oil nanoemulsion sprayed on the leaves had a significant promoting effect on the plant height, stem diameter, biomass and root weight of pepper and rice plants. The plant height, stem diameter, biomass and root weight of pepper in the treatment group increased by 1.28 times, 1.1 times, 1.68 times and 1.44 times respectively compared with the blank group, and the promoting effect on both the above-ground and underground parts was very significant. The plant height, stem diameter, biomass and root weight of rice in the treatment group increased by 1.36 times, 1.19 times, 1.50 times and 1.35 times respectively compared with the blank group. In summary, the experimental results show that fennel volatile oil sprayed on the leaves can also promote the growth of pepper and rice plants, and increase the accumulation of biomass.

[0137] The embodiments of the present invention have achieved some positive effects during the development or use process, and indeed have great advantages over the prior art. The following content is described in conjunction with data, charts, etc. of the test process.

[0138] Plant-derived volatile oils (EOs) are secondary metabolites of plants, widely found in various aromatic plants. As a typical small molecule compound, they have an inherent advantage in penetrating plant cell walls and play a vital "ecological role". Currently, EOs are mostly used in the medical field, food, cosmetics and perfume industries, and their potential in the green development of agriculture has not yet been fully explored.

[0139] Phytohormones are key regulators of plant growth and development, and their multifaceted roles in promoting plant growth and enhancing crop resistance to environmental stress are increasingly recognized. This study can promote the transformation of agricultural practices and promote the sustainability and resilience of the agricultural environment by preparing plant volatiles into preparations that can be directly sprayed on leaves or irrigated into roots to increase the content and stress resistance of plant hormones.

[0140] The above description is only a specific implementation mode of the present invention, but the protection scope of the present invention is not limited thereto. Any modifications, equivalent substitutions and improvements made by any technician familiar with the technical field within the technical scope disclosed by the present invention and within the spirit and principle of the present invention should be covered by the protection scope of the present invention.

Claims

1. A method for applying fennel volatile oil in promoting plant growth, characterized in that: The following steps are involved: Step 1: put 1 kg of dried fennel and distilled water in a 10L round-bottom flask at a ratio of 1:8, soak for 9 hours, and then distill for 7-10 hours using steam distillation; Step 2: After removing moisture from the collected fennel volatile oil with anhydrous sodium sulfate, the oil is stored in a brown bottle and placed in a -20°C refrigerator for later use.

2. The method for applying fennel volatile oil in promoting plant growth as claimed in claim 1, characterized in that: The invention discloses an application of volatile oil in promoting plant growth. The plants include the model plant Arabidopsis thaliana and the crops pepper and rice. The volatile oil is prepared by steam distillation.

3. The method for applying fennel volatile oil in promoting plant growth as claimed in claim 2, characterized in that: The volatile oil acts on the plant in the form of gas volatilization. In the laboratory, a filter paper is used to absorb the volatile oil and placed in a culture dish.

4. The method for applying fennel volatile oil in promoting plant growth as claimed in claim 2, characterized in that: The volatile oil is applied in the field using fennel volatile oil nanoemulsion, and the volatile oil uses a surfactant Tween 80 and a co-surfactant as a solvent and a dispersant; the co-surfactant is anhydrous ethanol.

5. A method for extracting fennel volatile oil, characterized in that: The method comprises the following steps: (a) Mix dried fennel and distilled water in a mass ratio of 1:8 in a 10-liter round-bottom flask and soak for at least 9 hours; (b) distilling the steeped fennel mixture using a steam distillation method for 7 to 10 hours; (c) collecting the obtained fennel volatile oil and removing the moisture therein using anhydrous sodium sulfate; (d) The fennel volatile oil after removal of moisture is stored in a brown bottle and placed in a refrigerator at -20°C for future use.

6. A method for treating Arabidopsis thaliana using fennel volatile oil, characterized in that: The method comprises the following steps: (a) preparing a 2DMSOT aqueous solution containing Tween 80 and DMSO, and using the solution to prepare a fennel volatile oil emulsion with a concentration of 0.5 mg / mL to 1 mg / mL; (b) Arabidopsis seeds were surface sterilized and placed on 1 / 8 MS basal medium for germination and growth; (c) After Arabidopsis thaliana germinated, filter paper sheets containing fennel essential oil emulsion were placed in petri dishes, with multiple replicates for each treatment; (d) Arabidopsis thaliana was grown under specific light and temperature conditions and its biomass was measured.

7. A method for preparing a fennel volatile oil nanoemulsion, characterized in that: The method comprises the following steps: (a) Tween 80 and anhydrous ethanol were mixed in a certain proportion, stirred on a magnetic stirrer and ultrasonicated in an ice bath; (b) When preparing the emulsion, the mixed surfactant and volatile oil are mixed, stirred on a magnetic stirrer, and then ultrasonicated in an ice bath; (c) Slowly adding water, and continuing stirring on a magnetic stirrer and then ultrasonicating in an ice bath until a nanoemulsion is formed.

8. A method for promoting pepper growth using fennel volatile oil nanoemulsion, characterized in that: The method comprises the following steps: (a) selecting pepper seedlings of uniform size for transplanting; (b) The pepper seedlings were treated with root irrigation using fennel volatile oil nanoemulsion at a concentration of 0.5 mg / mL, once every 10 days, for a total of 2 treatments; (c) The plant height, stem diameter, biomass and root weight of pepper were counted after treatment.

9. A method for promoting rice growth using fennel volatile oil nanoemulsion, characterized in that: The method comprises the following steps: (a) selecting rice seedlings of uniform size for transplanting; (b) using 0.5 mg / mL fennel volatile oil nanoemulsion to spray rice seedlings on the leaves until water drips from the leaves; (c) The plant height, stem diameter, biomass and root weight of rice were counted after treatment.

Images