Application of Bruguiera gymnorrhiza Extract in Controlling Snails and / or Reducing Methane Emissions from Soil
The treatment of Fushou snail and rice field soil through the snail leaf extract is achieved, and the methane emissions in the rice field are reduced, the problem of chemical agent pollution is solved, and an environmentally friendly and low-carbon agricultural solution is provided.
Patent Information
- Application Number
- CN202310249183.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2023-03-15
- Publication Date
- 2025-07-04
- Estimated Expiration
- 2043-03-15
AI Technical Summary
The prior art is difficult to effectively control the invasion of Fushou Snail and reduce methane emissions in the soil of rice fields. Chemical agents have problems of polluting the environment, and there are few researches on plant extracts in this regard.
Using shuibizi leaf extract, especially ethanol extract and n-butanol extract, the Fushou snail and rice field soil are treated with mixed solutions of different concentrations to achieve inhibition and killing of Fushou snails, while reducing soil methane emissions.
Within the concentration range of 0.20~1.20g/L, the extract of shuibizai leaves can effectively prevent and control snails, significantly reduce the methane emission rate in the rice field, and provide an environmentally friendly and low-carbon agricultural technology to ensure agricultural production and ecological security.
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Figure CN116473083B_ABST
Abstract
Description
Technical Field
[0001] The present invention belongs to the technical field of environment-friendly low-carbon agriculture for the utilization of plant resources for controlling snails, and relates to the application of an extract of Kandelia obovata in controlling snails and / or reducing methane emissions from soil (especially paddy soil); the specific application methods involve three aspects: First, the extract of the leaves of the mangrove plant Kandelia obovata can inhibit Pomacea canaliculata; Second, the extract of the leaves of the mangrove plant Kandelia obovata can kill Pomacea canaliculata; Third, the extract of the leaves of the mangrove plant Kandelia obovata can reduce methane emissions from soil (especially paddy soil). Background Art
[0002] Biological invasion and climate change are two important global environmental issues that have attracted much attention at present. Biological invasion, especially animal invasion, poses great harm to agricultural production and human health. Pomacea canaliculata is native to the Amazon River Basin in South America. It is one of the first 16 alien species to invade China and is also one of the world's 100 most invasive alien species. Pomacea canaliculata has high reproductive capacity, fast growth rate, strong adaptability, wide food habits and large food intake. It has broken out in many provinces in China, resulting in reduced yields of aquatic crops such as rice, water bamboo, and lotus root, and causing irreversible damage to the local ecological system balance. Pomacea canaliculata also carries Angiostrongylus cantonensis, seriously threatening human health and bringing harm to China's agricultural production, ecological environment and economy.
[0003] Methane (CH4) is a potent greenhouse gas second only to CO2. Its global warming potential is 84 times and 28 times that of CO2 on the 20-year and 100-year scales respectively. With the obvious increase in the greenhouse effect, it is urgent to reduce methane emissions. Paddy fields are the main source of CH4 emissions in crop systems. As climate change gradually becomes a global problem threatening agricultural production, how to effectively reduce CH4 emissions from paddy soil has become the focus of attention in agriculture. Plant extracts are currently mostly used to reduce methane emissions from ruminants. They are low-toxic, low-harm, diverse in variety, wide in source, and environmentally friendly. However, there is little research on whether plant extracts can be used to reduce methane emissions from soil, and it has not received extensive attention.
[0004] The development and utilization of plant resources is an important way for biological snail control and killing. It has the characteristics of convenient use, low cost, and relatively small environmental pollution effect. At present, the main method for controlling Pomacea canaliculata in China is chemical agents, which have problems such as high price, strong irritation and toxicity, and environmental pollution, affecting the normal flow of matter and energy in the ecosystem.
[0005] Kandelia obovata is a common species in mangroves. Kandelia obovata has a large amount of fallen leaves every year, but the utilization of mangrove resources is still relatively low. The alcohols and quinones contained in the leaves of Kandelia obovata endow it with pharmacological properties such as bactericidal effects. According to research, the annual yield of Kandelia obovata litter per hectare is 6188 kg, and these leaves cannot be utilized, resulting in a waste of resources. Existing research has found that compounds such as sterols, triterpenes, quinones, flavonoids, and organic acids in the leaves of Kandelia obovata have pharmacological activities such as antibacterial and antioxidant effects, but there are currently no reports on the use of Kandelia obovata to control Pomacea canaliculata and reduce methane emissions in the soil. Summary of the Invention
[0006] In order to overcome the deficiencies of the prior art, the purpose of the present invention is to provide an application of Kandelia obovata extract in controlling snails and / or reducing soil methane emissions. The application effect of this extract is "three birds with one stone", that is, "snail inhibition, snail killing, and emission reduction".
[0007] The present invention uses Kandelia obovata plants to control Pomacea canaliculata, and finally finds that when the concentration of Kandelia obovata extract is in the range of 0.20 - 1.20 g / L, it can not only effectively control Pomacea canaliculata, but also reduce the methane emission rate of paddy field soil to a certain extent, achieving the reduction of greenhouse gas emissions while eliminating invasive animals, creating an environmentally friendly and low-carbon agricultural technology to ensure the safety of agricultural production and the ecosystem.
[0008] The purpose of the present invention is achieved by the following technical solutions:
[0009] Application of Kandelia obovata extract in controlling snails and / or reducing soil methane emissions.
[0010] Further, the Kandelia obovata extract is an extract of Kandelia obovata leaves;
[0011] Further, the final concentration of the Kandelia obovata leaf extract is 0.20 - 1.20 g / L.
[0012] Further, the Kandelia obovata leaf extract is at least one of an ethanol extract of Kandelia obovata leaves and a n-butanol extract of Kandelia obovata leaves; furthermore, the mass ratio of the ethanol extract of Kandelia obovata leaves to the n-butanol extract of Kandelia obovata leaves is 1:1 - 1:2.
[0013] Further, the snail is Pomacea canaliculata;
[0014] Further, the soil is paddy field soil.
[0015] Preferably, the application is:
[0016] (1) Application of an ethanol extract of Kandelia obovata leaves or a n-butanol extract of Kandelia obovata leaves in inhibiting Pomacea canaliculata; and / or
[0017] (2) Application of ethanol extract of Kandelia obovata leaves and n-butanol extract of Kandelia obovata leaves in killing Pomacea canaliculata; and / or
[0018] (3) Application of ethanol extract of Kandelia obovata leaves and / or n-butanol extract of Kandelia obovata leaves in reducing soil methane emissions.
[0019] Preferably, the dosage of the Kandelia obovata leaf extract in reducing soil methane emissions is 0.20 - 1.20 g / L, and further preferably 1.20 g / L.
[0020] The said application includes the steps:
[0021] Adding the Kandelia obovata leaf extract into the water body containing Pomacea canaliculata, wherein the dosage of the Kandelia obovata leaf extract is 0.20 - 1.20 g / L;
[0022] The said Kandelia obovata leaf extract includes at least one of ethanol extract of Kandelia obovata leaves and n-butanol extract of Kandelia obovata leaves; furthermore, the mass ratio of ethanol extract of Kandelia obovata leaves to n-butanol extract of Kandelia obovata leaves is 1:1 - 1:2.
[0023] Preferably, the said water body is a paddy field water body.
[0024] In the solution, the Kandelia obovata leaves mentioned are Kandelia obovata, belonging to the genus Kandelia of the family Rhizophoraceae. The behavioral responses of Pomacea canaliculata include two states: inhibited and normal. The inhibited state includes behaviors such as closing the operculum, foraging, and escaping. The semi-inhibited state includes behaviors such as attaching to the wall and escaping. The normal behavior is continuous movement at the bottom of the water. For the methane emissions from paddy field soil, continuous measurement is carried out using a LI-7810 portable greenhouse gas analyzer, and the emission rate is significantly reduced. Experiments show that the dosage of the ethanol extract of Kandelia obovata leaves affects the behavioral responses of Pomacea canaliculata. When the dosage >= 0.20 g / L, the behaviors of Pomacea canaliculata produce responses, and Pomacea canaliculata is in the inhibited and semi-inhibited states, unable to forage, and the methane emissions from paddy field soil are significantly reduced. The ethanol extract has a negative effect on the methane production process in paddy field soil and a positive effect on the methane oxidation process in paddy field soil. While < 0.20 g / L has no obvious effect on the normal foraging activities of Pomacea canaliculata, and the physiological metabolism in the body has enough defenses to cope with the interference of the extract, and has no obvious effect on the methane emissions from paddy field soil. Preferably, the dosage of the ethanol extract of Kandelia obovata leaves is 1.2 g / L. At this dosage, the inhibitory effect on Pomacea canaliculata is obvious, and it can effectively reduce the methane emissions from paddy fields.
[0025] The dosage of the n-butanol extract from the leaves of Kandelia obovata directly affects the inhibitory effect on Pomacea canaliculata. When the effective dose of the n-butanol extract ≥ 0.20 g / L, Pomacea canaliculata begins to be inhibited. As the concentration increases, the inhibition rate increases. Below 0.20 g / L, the effect on the survival of Pomacea canaliculata is not obvious, and below this dosage, it cannot play an inhibitory role on Pomacea canaliculata. Preferably, the dosage of the n-butanol extract from the leaves of Kandelia obovata is 0.2 - 1.0 g / L. At this dosage, the inhibitory effect on Pomacea canaliculata is obvious, and the time to achieve 100% inhibition of Pomacea canaliculata is 1 h.
[0026] The dosage of the mixture of the ethanol extract and the n-butanol extract from the leaves of Kandelia obovata affects the effect of killing Pomacea canaliculata and reducing methane emissions. The death of Pomacea canaliculata is characterized by the protrusion of the abdominal foot and no longer retracting. After gently pulling, the phenomenon of shell and meat separation occurs in Pomacea canaliculata. When the effective dose of the mixed extract ≥ 0.20 g / L, Pomacea canaliculata begins to die. As the concentration increases, the mortality rate increases. The methane emission from paddy field soil is significantly reduced. The mixed extract shows a negative effect on the methane production process in paddy field soil and a positive effect on the methane oxidation process in paddy field soil. Below 0.20 g / L, the effect on the survival of Pomacea canaliculata is not obvious, and there is partial damage to the organ tissues of Pomacea canaliculata. Pomacea canaliculata maintains normal growth and reproduction through self-repair mechanisms. It has been experimentally proven that the lower limit of the dosage of the mixture of ethanol extract and n-butanol extract is 0.20 g / L. Below this dosage, it cannot play a toxic effect on Pomacea canaliculata. Therefore, the mass ratio of the ethanol extract powder to the n-butanol extract powder is 1:1 - 1:2, and the concentration is 0.20 - 1.20 g / L. Within this range, the mixed extract can achieve the dual effects of killing snails and reducing methane emissions. Preferably, the mass ratio of the ethanol extract to the n-butanol extract in the extract from the leaves of Kandelia obovata is 1:1.5, and the dosage is 1.0 g / L. At this dosage, it can kill 100% of Pomacea canaliculata, and the time is about 72 h.
[0027] The preparation method of the ethanol extract from the leaves of Kandelia obovata includes the following steps:
[0028] Take the leaves of Kandelia obovata, wash, dry, crush them into powder, and pass through a 40 - 70 mesh sieve to obtain the powder of the leaves of Kandelia obovata; then soak it with an ethanol aqueous solution, perform ultrasonic extraction, filter, and extract the solid residue 1 - 2 more times, combine the filtrates, and dry to obtain the ethanol extract from the leaves of Kandelia obovata;
[0029] Preferably, the drying is carried out by drying at 100 - 108 °C for 1 hour first, and then drying at 70 - 80 °C to constant weight;
[0030] Preferably, the mass-to-volume ratio of the powder of the leaves of Kandelia obovata to the ethanol aqueous solution is 1:15 - 20; further preferably 1:18.
[0031] Preferably, the volume fraction of ethanol in the ethanol aqueous solution is 65 - 75%; further preferably 70%.
[0032] Preferably, the soaking time is 22 - 26 h; more preferably 24 h.
[0033] Preferably, the soaking is carried out at room temperature, which refers to 23 - 27 °C.
[0034] Preferably, the ultrasonic extraction time is 28 - 33 min; more preferably 30 min.
[0035] The morphology of the Bruguiera sexangula leaves, especially the particle size of the powder, will also affect the extraction effect and the efficiency of inhibiting the behavior of Pomacea canaliculata. If it exceeds the range of 40 - mesh sieve and 70 - mesh sieve, it is difficult to obtain plant extracts or effectively inhibit the effect of Pomacea canaliculata. Preferably, the sieving through 40 - 70 mesh is sieving through 60 mesh; the Bruguiera sexangula leaf powder of this size is more easily used to obtain extracts and can most effectively inhibit Pomacea canaliculata.
[0036] The preparation method of the n - butanol extract of Bruguiera sexangula leaves includes the following steps:
[0037] Dissolve the ethanol extract of the above - mentioned Bruguiera sexangula leaves in water, add n - butanol for extraction, repeat the extraction until the color of the n - butanol in the upper layer liquid does not change, combine the extraction liquid, rotary evaporate and dry to obtain the n - butanol extract of Bruguiera sexangula leaves.
[0038] Preferably, the mass ratio of the ethanol extract of Bruguiera sexangula leaves to water is 2.5 - 3.5:1; more preferably 3:1.
[0039] The present invention has the following advantages and effects compared with the prior art:
[0040] (1) The plant material Bruguiera sexangula is a common plant in South China, which is easy to obtain, simple to operate, convenient for farmers to operate in the field, saves costs and reduces pollution.
[0041] (2) It provides new ideas for the control of harmful invasive animals and has great reference value for the research of invasion ecology and biological invasion control technology.
[0042] (3) Through the extract of Bruguiera sexangula leaves, it can effectively control Pomacea canaliculata at a certain concentration (0.20 - 1.20 g / L), and at the same time can effectively reduce the methane emission of paddy field soil, achieving the effect of avoiding pollution and reducing emissions. BRIEF DESCRIPTION OF THE DRAWINGS
[0043] Figure 1 It is the influence of the ethanol extract of Bruguiera sexangula leaves on the behavior of Pomacea canaliculata at a concentration of 0.20 g / L.
[0044] Figure 2 It is the influence of the ethanol extract of Bruguiera sexangula leaves on the behavior of Pomacea canaliculata at a concentration of 0.40 g / L.
[0045] Figure 3 The behavioral effects of ethanol extracts from Bruguiera gymnorrhiza leaves on Pomacea canaliculata at a concentration of 1.20 g / L.
[0046] Figure 4 The reduction of methane emission rate in paddy soil by ethanol extracts from Bruguiera gymnorrhiza leaves at a concentration of 0.20 g / L.
[0047] Figure 5 The reduction of methane emission rate in paddy soil by ethanol extracts from Bruguiera gymnorrhiza leaves at a concentration of 0.40 g / L.
[0048] Figure 6 The reduction of methane emission rate in paddy soil by ethanol extracts from Bruguiera gymnorrhiza leaves at a concentration of 1.20 g / L.
[0049] Figure 7 The effects of ethanol extracts from Bruguiera gymnorrhiza leaves at different concentrations on methane production in paddy soil.
[0050] Figure 8 The behavioral effects of n-butanol extracts from Bruguiera gymnorrhiza leaves on Pomacea canaliculata at a concentration of 0.20 g / L.
[0051] Figure 9 The behavioral effects of n-butanol extracts from Bruguiera gymnorrhiza leaves on Pomacea canaliculata at a concentration of 0.80 g / L.
[0052] Figure 10 The behavioral effects of n-butanol extracts from Bruguiera gymnorrhiza leaves on Pomacea canaliculata at a concentration of 1.0 g / L.
[0053] Figure 11 The reduction of methane emission rate in paddy soil by n-butanol extracts from Bruguiera gymnorrhiza leaves at a concentration of 0.20 g / L.
[0054] Figure 12 The reduction of methane emission rate in paddy soil by n-butanol extracts from Bruguiera gymnorrhiza leaves at a concentration of 0.80 g / L
[0055] Figure 13 The reduction of methane emission rate in paddy soil by n-butanol extracts from Bruguiera gymnorrhiza leaves at a concentration of 1.0 g / L.
[0056] Figure 14 The effects of n-butanol extracts from Bruguiera gymnorrhiza leaves at different concentrations on methane production in paddy soil.
[0057] Figure 15 The snail-killing effects of mixed extracts from Bruguiera gymnorrhiza leaves at concentrations of 0.2 g / L, 0.8 g / L, and 1.0 g / L.
[0058] Figure 16Comparison of the reduction of methane emission rate in paddy soil between the mixed extract of Kandelia obovata at concentrations of 0.2 g / L, 0.8 g / L, 1.0 g / L and the control group.
[0059] Figure 17 Effects of the mixed extract of Kandelia obovata at different concentrations on the methane production in paddy soil and the snail-killing effect for 96 h. Detailed implementation manners
[0060] The present invention will be further described in detail below in conjunction with embodiments and the accompanying drawings, but the implementation manners of the present invention are not limited thereto.
[0061] For the test methods without specific experimental conditions in the following embodiments, they are generally in accordance with conventional experimental conditions or the experimental conditions recommended by the manufacturer. The materials, reagents, etc. used, unless otherwise specified, are reagents and materials obtained from commercial channels.
[0062] Embodiment 1
[0063] This embodiment studies the inhibition of the activities of Pomacea canaliculata in paddy fields by using ethanol extracts of leaves of the mangrove plant Kandelia obovata at different concentrations. The specific steps include:
[0064] 1. Collect the leaves of the mangrove plant Kandelia obovata, wash the plant materials, dry them in a forced-air drying oven at 105 °C for 1 hour, then dry them at 75 °C until constant weight, and then crush them into powder and pass through a 60-mesh sieve;
[0065] 2. Take 200 g of the powdered plant materials and soak them in 70% ethanol at a ratio of 1:18 (mass: volume) at room temperature for 24 h, then perform ultrasonic extraction for 30 min, filter the sample, extract the solid residue twice more, combine the three filtrates, and dry them to obtain the ethanol extract of Kandelia obovata leaves.
[0066] 3. When in use, weigh a certain amount of the ethanol extract of Kandelia obovata leaves, disperse or dissolve the extract by ultrasonic wave to prepare a suspension with a required concentration of 10 g / L. Take 10 mL, 20 mL, and 40 mL respectively and make up to 1 L volumetric flask to obtain concentrations of 0.20 g / L, 0.40 g / L, and 1.2 g / L. Put 10 Pomacea canaliculata into a plastic basin, add the ethanol extract of Kandelia obovata leaves, and conduct three parallel tests and one control group. The control group uses dechlorinated water to detect the snail-inhibiting effect of the ethanol extract of Kandelia obovata leaves.
[0067] The results show that after treating Pomacea canaliculata with 0.20 g / L for 6 h, 90% of the Pomacea canaliculata are inhibited, among which 10% escape to the water surface and 80% of the Pomacea canaliculata with closed opercula; after 72 h, the inhibition rate reaches 100% ( Figure 1 ), and the inhibition rate of treating Pomacea canaliculata with 0.40 g / L for 24 h reaches 100% ( Figure 2) The inhibition rate reached 80% when Pomacea canaliculata was treated with 1.2 g / L for 30 min, and reached 100% after 6 h. Figure 3 )
[0068] Example 2
[0069] This example studied the use of ethanol extracts from the leaves of the mangrove plant Bruguiera gymnorrhiza at different concentrations to inhibit Pomacea canaliculata and reduce methane emissions from paddy field soil. The specific steps are as follows:
[0070] 1. Collect the leaves of the mangrove plant Bruguiera gymnorrhiza, wash the plant materials, dry them in a forced-air drying oven at 105 °C for 1 hour, then dry them at 75 °C until constant weight, and then crush them into powder and pass through a 60-mesh sieve.
[0071] 2. Take 200 g of the powdered plant material and soak it in 70% ethanol at a ratio of 1:18 (mass: volume) at room temperature for 24 h, then perform ultrasonic extraction for 30 min, filter the sample, extract the solid residue twice more, combine the three filtrates, and dry them to obtain the ethanol extract of Bruguiera gymnorrhiza leaves.
[0072] 3. Measure the methane emission rate of paddy field soil. In the control group, first add 5 cm of paddy field soil to a closed device, then add a 5-cm water layer (500 mL), and finally, at 22.5 °C, continuously detect the methane emission rate of paddy field soil using a LI-7810 portable greenhouse gas analyzer. In the experimental groups, draw out 100 mL of clear water with a syringe, dissolve 0.1 g, 0.2 g, and 0.6 g of the ethanol extract of Bruguiera gymnorrhiza leaves in 100 mL of clear water respectively, and then inject them back. Finally, at 22.5 °C, continuously detect the methane emission rate of paddy field soil for three different concentrations of ethanol extracts, namely 0.20 g / L, 0.40 g / L, and 1.20 g / L.
[0073] The test results showed that after treating paddy field soil with ethanol extracts at concentrations of 0.20 g / L, 0.40 g / L, and 1.20 g / L respectively, the average methane emission rate of paddy field soil at a concentration of 0.20 g / L was 0.66 ppbv / min, which was 16.4% of the control group; the maximum methane emission rate was 0.67 ppbv / min, which was 16.3% of the control group; the minimum methane emission rate was 0.65 ppbv / min, which was 16.5% of the control group. Figure 4 ) At a concentration of 0.40 g / L, the average methane emission rate of paddy field soil was 0.62 ppbv / min, which was 15.4% of the control group; the maximum methane emission rate was 0.63 ppbv / min, which was 15.4% of the control group; the minimum methane emission rate was 0.61 ppbv / min, which was 15.3% of the control group. Figure 5);Its average methane emission rate in paddy soil at a concentration of 1.20 g / L was 0.55 ppbv / min, which was 13.5% of the control group; the maximum methane emission rate was 0.55 ppbv / min, which was 13.5% of the control group; the minimum methane emission rate was 0.54 ppbv / min, which was 13.6% of the control group( Figure 6 );
[0074] The cumulative methane emission per cubic centimeter at a concentration of 0.20 g / L was 0.83 mg, which was 76.1% of the control group; the cumulative methane emission per cubic centimeter at a concentration of 0.40 g / L was 0.15 mg, which was 13.7% of the control group; the cumulative methane emission per cubic centimeter at a concentration of 1.20 g / L was 0.11 mg, which was 10.7% of the control group( Figure 7 )。The methane rate with the addition of the ethanol extract of Bruguiera sexangula leaves decreased significantly. The ethanol extract of Bruguiera sexangula leaves can not only inhibit Pomacea canaliculata, but also reduce methane emissions from paddy soil.
[0075] Example 3
[0076] This example uses the n-butanol extracts of the leaves of the mangrove plant Bruguiera sexangula at different concentrations to control Pomacea canaliculata in paddy fields. The specific steps include:
[0077] 1. Collect the leaves of the mangrove plant Bruguiera sexangula, wash the plant materials, dry them in a forced-air drying oven at 105 °C for 1 hour, then dry them at 75 °C until constant weight, and then crush them into powder and pass through a 60-mesh sieve;
[0078] 2. Take 200 g of the powdered plant material and soak it in 70% ethanol at a ratio of 1:18 (mass: volume) at room temperature for 24 h, then perform ultrasonic extraction for 30 min, filter the sample, extract the solid residue twice more, combine the three filtrates, and dry them to obtain the ethanol extract of Bruguiera sexangula leaves.
[0079] 3. Dissolve the ethanol extract of Bruguiera sexangula leaves in water at a ratio of 3:1, add n-butanol for extraction, repeat the extraction until the color of the n-butanol in the upper layer does not change, mix and rotary evaporate the extraction solution, and dry it to obtain the n-butanol extract of Bruguiera sexangula leaves. Take an appropriate amount of the n-butanol extract of Bruguiera sexangula leaves and prepare concentrations of 0.20 g / L, 0.80 g / L, and 1.0 g / L. Put 10 Pomacea canaliculata in a plastic basin, add the n-butanol extract of Bruguiera sexangula leaves, and conduct three parallel tests with one control group. The control group uses dechlorinated water to detect the effect of the n-butanol extract of Bruguiera sexangula leaves in inhibiting Pomacea canaliculata.
[0080] The test results showed that the inhibition rate of treating Pomacea canaliculata with 0.20 g / L for 6 h reached 100%( Figure 8 ),and the inhibition rate of treating Pomacea canaliculata with 0.80 g / L for 1 h reached 100%( Figure 9), the inhibition rate of the 1.0 g / L butanol extract of Avicennia marina leaves on Pomacea canaliculata for 1 h reached 100%( Figure 10 ).
[0081] Example 4
[0082] This example studied the use of butanol extracts of mangrove plant Avicennia marina leaves at different concentrations to reduce paddy soil emissions. The specific steps included:
[0083] 1. Collect the leaves of the mangrove plant Avicennia marina, wash the plant materials, dry them in a forced-air drying oven at 105 °C for 1 hour, then dry them at 75 °C until constant weight, and then crush them into powder and pass through a 60-mesh sieve;
[0084] 2. Take 200 g of the powdered plant material and soak it in 70% ethanol at a ratio of 1:18 (mass: volume) at room temperature for 24 h, then perform ultrasonic extraction for 30 min, filter the sample, extract the solid residue twice more, combine the three filtrates, and dry them to obtain the ethanol extract of Avicennia marina leaves.
[0085] 3. Dissolve the ethanol extract of Avicennia marina leaves in water at a ratio of 3:1, add butanol for extraction, repeat the extraction until the color of the upper-layer butanol does not change, mix and rotary evaporate the extraction solution, and dry it to obtain the butanol extract of Avicennia marina leaves.
[0086] 4. Measure the methane emission rate of paddy soil:
[0087] Control group: First add 5 cm of paddy soil to the closed device, then add a 5 cm water layer (500 mL), and finally continuously detect the methane emission rate of the paddy soil at 22.5 °C using a LI-7810 portable greenhouse gas analyzer. Experimental group: After measuring the control group, dissolve 0.1 g, 0.4 g, and 0.5 g of the butanol extract of Avicennia marina leaves in 100 mL of clear water and then inject them. Finally, continuously detect the methane emission rate of the paddy soil with three different concentrations of the butanol extract of Avicennia marina leaves, namely 0.20 g / L, 0.80 g / L, and 1.00 g / L, at 22.5 °C using a LI-7810 portable greenhouse gas analyzer.
[0088] The test results showed that after treating the paddy soil with butanol extracts at concentrations of 0.20 g / L, 0.80 g / L, and 1.00 g / L respectively, the average methane emission rate of the paddy soil at a concentration of 0.20 g / L was 2.42 ppbv / min, which was 60% of the control group; the maximum methane emission rate was 2.48 ppbv / min, which was 61% of the control group; the minimum methane emission rate was 2.33 ppbv / min, which was 58.3% of the control group( Figure 11 );
[0089] At a concentration of 0.80 g / L, the average rate of methane emission from paddy soil was 1.56 ppbv / min, which was 38.7% of the control group; the maximum rate of methane emission was 1.61 ppbv / min, which was 40% of the control group; the minimum rate of methane emission was 1.53 ppbv / min, which was 38.4% of the control group( Figure 12 );
[0090] The experimental results of the effect of the n-butanol extract of Bruguiera gymnorrhiza leaves on methane emission from paddy soil at a concentration of 1.00 g / L were as follows: the average rate of methane emission was 1.17 ppbv / min, which was 29.0% of the control group; the maximum rate of methane emission was 1.21 ppbv / min, which was 29.5% of the control group; the minimum rate of methane emission was 1.16 ppbv / min, which was 29.0% of the control group( Figure 13 );
[0091] The cumulative methane emission per cubic centimeter at a concentration of 0.20 g / L was 0.72 mg, which was 66% of the control group; the cumulative methane emission per cubic centimeter at a concentration of 0.80 g / L was 0.55 mg, which was 50.4% of the control group; the cumulative methane emission per cubic centimeter at a concentration of 1.00 g / L was 0.23 mg, which was 21.1% of the control group( Figure 14 ). The methane rate decreased significantly after adding the n-butanol extract of Bruguiera gymnorrhiza leaves. The n-butanol extract of Bruguiera gymnorrhiza leaves can not only inhibit Pomacea canaliculata, but also reduce methane emission from paddy soil.
[0092] Example 5
[0093] This example studied the use of the ethanol extract and n-butanol extract of Bruguiera gymnorrhiza leaves to kill Pomacea canaliculata in paddy fields and reduce methane emissions from paddy soil. The specific steps were as follows:
[0094] 1. Collect the leaves of the mangrove plant Bruguiera gymnorrhiza, wash the plant materials, dry them in a forced-air drying oven at 105 °C for 1 hour, then dry them at 75 °C until constant weight, crush them into powder, and pass through a 60-mesh sieve;
[0095] 2. Take 200 g of the powdered plant material and soak it in 70% ethanol at a ratio of 1:18 (mass: volume) at room temperature for 24 h, then extract it by ultrasound for 30 min, filter the sample, extract the solid residue twice more, combine the three filtrates, and dry them to obtain the ethanol extract of Bruguiera gymnorrhiza leaves.
[0096] 3. Dissolve the ethanol extract of Bruguiera gymnorrhiza leaves in water at a ratio of 3:1, add n-butanol for extraction, repeat the extraction until the color of the n-butanol in the upper layer does not change, mix and rotary evaporate the extraction solution, and dry it to obtain the n-butanol extract of Bruguiera gymnorrhiza leaves.
[0097] 4. Mix the powders of the ethanol extract and n-butanol extract of Bruguiera sexangula leaves (mass ratio 1:1.5) to obtain the mixed extract of Bruguiera sexangula leaves. Take appropriate amounts and prepare concentrations of 0.2 g / L, 0.8 g / L, and 1.0 g / L respectively. Place 10 Pomacea canaliculata in a plastic basin, add the mixed extract of Bruguiera sexangula leaves, with three parallel tests and one control group. The control group uses dechlorinated water to detect the effect of the mixed extract of Bruguiera sexangula leaves on Pomacea canaliculata.
[0098] 5. Measure the methane emission rate of paddy field soil. Control group: First, add 5 cm of paddy field soil to a closed device, then add a 5 cm water layer (500 mL), and finally, at 22.5 °C, continuously detect the methane emission rate of paddy field soil using a LI-7810 portable greenhouse gas analyzer. Experimental group: After measuring the control group, take 0.1 g, 0.4 g, and 0.5 g of the ethanol extract and n-butanol extract of Bruguiera sexangula leaves mixed at a mass ratio of 1:1.5 and dissolve them in 500 mL of clear water respectively (i.e., the concentrations of the mixed extract of Bruguiera sexangula leaves are 0.2 g / L, 0.8 g / L, and 1.0 g / L), and directly pour them into the anhydrous soil. Finally, at 22.5 °C, continuously detect the methane emission rate of paddy field soil using a LI-7810 portable greenhouse gas analyzer.
[0099] The experimental results show that when the concentration of the mixed extract of Bruguiera sexangula leaves is 0.20 g / L, after 72 h of poisoning, the mortality rate of Pomacea canaliculata is 65%, and after 96 h, the mortality rate of Pomacea canaliculata reaches 100%; when the concentration of the mixed extract of Bruguiera sexangula leaves is 0.80 g / L, after 72 h of poisoning, the mortality rate of Pomacea canaliculata is 70%, and after 96 h, the mortality rate of Pomacea canaliculata reaches 100%; when the concentration of the mixed extract of Bruguiera sexangula leaves is 1.00 g / L, after 48 h of poisoning, the mortality rate of Pomacea canaliculata is 90%, and after 72 h, the mortality rate of Pomacea canaliculata reaches 100% ( Figure 15 ).
[0100] The average methane emission rate of the mixed extract of Bruguiera sexangula leaves at 0.20 g / L was 0.72 ppbv / min, which was 17.8% of the control group; the maximum methane emission rate was 0.73 ppbv / min, which was 17.8% of the control group; the minimum methane emission rate was 0.71 ppbv / min, which was 17.8% of the control group; the average methane emission rate of the mixed extract of Bruguiera sexangula leaves at 0.80 g / L was 0.54 ppbv / min, which was 13.4% of the control group; the maximum methane emission rate was 0.55 ppbv / min, which was 13.4% of the control group; the minimum methane emission rate was 0.53 ppbv / min, which was 13.3% of the control group; the average methane emission rate of the mixed extract of Bruguiera sexangula leaves at 1.00 g / L was 0.32 ppbv / min, which was 7.9% of the control group; the maximum methane emission rate was 0.33 ppbv / min, which was 8.0% of the control group; the minimum methane emission rate was 0.31 ppbv / min, which was 7.8% of the control group( Figure 16 );
[0101] Overall, the cumulative methane emission per cubic centimeter of the mixed extract at 0.20 g / L was 0.160 mg, which was 14.7% of the control group, and the mortality rate of Pomacea canaliculata reached 100% at 96 h; the cumulative methane emission per cubic centimeter at 0.80 g / L was 0.100 mg, which was 9.2% of the control group, and the mortality rate of Pomacea canaliculata reached 100% at 96 h; the cumulative methane emission per cubic centimeter at 1.00 g / L was 0.082 mg, which was 7.5% of the control group, and the mortality rate of Pomacea canaliculata reached 100% at 96 h( Figure 17 ). In the experiment of the mixed extract of Bruguiera sexangula leaves, the mixed extract of Bruguiera sexangula leaves can not only kill Pomacea canaliculata, but also reduce the methane emission from paddy field soil.
[0102] The above embodiments are the preferred embodiments of the present invention, but the embodiments of the present invention are not limited by the above embodiments. Any other changes, modifications, substitutions, combinations, and simplifications made without departing from the spirit and principle of the present invention shall be equivalent replacement methods and shall be included in the protection scope of the present invention.
Claims
1. Application of Bruguiera gymnorrhiza extract in controlling snails and / or reducing soil methane emissions, characterized in that: Kandelia obovata The Kandelia obovata extract is an extract of Kandelia obovata leaves; the final concentration of the Kandelia obovata leaf extract is 0.20 - 1.20 g / L; The Kandelia obovata leaf extract is at least one of an ethanol extract of Kandelia obovata leaves and a n-butanol extract of Kandelia obovata leaves; the n-butanol extract of Kandelia obovata leaves is obtained by extracting the ethanol extract of Kandelia obovata leaves with n-butanol; The snail is Pomacea canaliculata.
2. The application according to claim 1, characterized in that: The soil is paddy soil.
3. The application according to claim 1, characterized in that: The mass ratio of the ethanol extract of Kandelia obovata leaves to the n-butanol extract of Kandelia obovata leaves is 1:1 - 1:
2.
4. The application according to any one of claims 1 to 3, characterized in that: The application is: (1) The application of the ethanol extract of Kandelia obovata leaves or the n-butanol extract of Kandelia obovata leaves in inhibiting Pomacea canaliculata; and / or (2) The application of the ethanol extract of Kandelia obovata leaves and the n-butanol extract of Kandelia obovata leaves in killing Pomacea canaliculata; and / or (3) The application of the ethanol extract of Kandelia obovata leaves and / or the n-butanol extract of Kandelia obovata leaves in reducing soil methane emissions.
5. The application according to any one of claims 1 - 3, characterized in that: The application includes the steps: Adding the Kandelia obovata leaf extract to the water body containing Pomacea canaliculata, wherein the dosage of the Kandelia obovata leaf extract is 0.20 - 1.20 g / L.
6. The application according to claim 5, wherein: The water body is a paddy water body.
7. The application according to any one of claims 1 - 3, characterized in that: The preparation method of the ethanol extract of Kandelia obovata leaves includes the following steps: Taking Kandelia obovata leaves, washing, drying, pulverizing into powder, passing through a 40 - 70 mesh sieve to obtain Kandelia obovata leaf powder; then soaking with an ethanol aqueous solution, ultrasonic extracting, filtering and then extracting the solid residue 1 - 2 times, combining the filtrates, drying to obtain the ethanol extract of Kandelia obovata leaves; The preparation method of the n-butanol extract of Kandelia obovata leaves includes the following steps: Dissolving the ethanol extract of Kandelia obovata leaves in water, adding n-butanol for extraction, repeating the extraction until the color of the n-butanol in the upper layer liquid does not change, combining the extraction liquids, rotary evaporation and drying to obtain the n-butanol extract of Kandelia obovata leaves.
8. The application according to claim 7, characterized in that: The drying is first drying at 100 - 108 °C for 1 hour, and then drying at 70 - 80 °C to constant weight; The mass-volume ratio of the Kandelia obovata leaf powder to the ethanol aqueous solution is 1:15 - 20; The volume fraction of ethanol in the ethanol aqueous solution is 65 - 75%; The soaking time is 22 - 26 h; The soaking is carried out at room temperature, and room temperature refers to 23 - 27 °C; The ultrasonic extraction time is 28 - 33 min; The mass ratio of the ethanol extract of Kandelia obovata leaves to water is 2.5 - 3.5:1.
Citation Information
Patent Citations
Novel natrural algicide with low toxicity to non-target organisms
WO2018133114A1