CN105851067B - A kind of fennel extracting solution and preparation method and the growth for being used for control duckweed - Google Patents

Abstract

The invention discloses a fennel extract and a preparation method thereof, and uses the fennel extract to control the growth of duckweed, and relates to the field of water body protection. In the method, fresh fennel stems and leaves are soaked and extracted to obtain fennel extract. Using the fennel extract of the invention to control the growth of duckweed, or to kill duckweed has the advantages of environmental protection, harmlessness to humans and animals, and the like, and has broad application prospects.

Description

A kind of fennel extract and its preparation method and its use to control the growth of duckweed

technical field

The invention relates to the field of water body protection, and more specifically relates to an fennel extract and a preparation method, and uses the fennel extract to control the growth of duckweed or kill duckweed to protect the balance of aquatic ecology.

Background technique

Duckweed ( Lemna minor L.), a floating plant belonging to the Duckweed family of Araceae, is widely distributed in ditches, rivers, ponds and lakes all over the world. In recent years, with the intensification of pollution of nutrients such as nitrogen and phosphorus in water bodies, and the lack of natural enemies of duckweed (such as ducks and grass carp) brought about by intensive farming, duckweed is often found in some ditches, rivers, and ponds under suitable climatic conditions. Even explosive growth in lakes. Duckweed itself has a strong ability to absorb and purify nitrogen, phosphorus, and heavy metals in the water body. It can purify water quality when it grows in an appropriate amount, and is an excellent animal feed; however, as a floating plant, its explosive growth will not only reduce the water quality. Dissolved oxygen hinders underwater lighting, affects the growth of underwater plants, destroys the original aquatic ecological balance, and also affects water navigation, landscape and water resource utilization. Therefore, the control of water body duckweed is an environmental problem to be solved urgently.

At present, duckweed control methods in water bodies mainly include manual salvage, biological control, and chemical herbicide control. Manual salvage is time-consuming and laborious, and due to the characteristics of duckweed itself that is easy to spread, it is difficult to completely remove duckweed, and the remaining duckweed It is easy to break out again when the conditions are suitable. In addition, it is difficult to manually salvage the duckweed on the surface of some wet vegetation and canopy-type submerged plants. At present, biological control mainly uses ducks, grass carp, etc. to prey on duckweed to achieve the control of duckweed. This method may be effective for duckweed control in the early stage, but after the duckweed outbreak causes environmental problems, the animals are restocked. Due to the proliferation of duckweed Rapidly, animal feeding cannot be controlled, but the density effect of duckweed is reduced to a certain extent; in addition, in water bodies, animals may preferentially eat their favorite food, such as ducks will preferentially prey on small fish, snails and other aquatic organisms. Animals, grass carp give priority to suitable submerged plants and so on. Although chemical herbicides have a good killing effect on duckweed, their secondary harm to the environment cannot be ignored. Compared with chemical herbicides, allelochemicals or natural herbicides have the characteristics of high efficiency, environmental protection, and strong selectivity, and have broad application prospects.

Contents of the invention

The purpose of the present invention is to provide a fennel extract and a preparation method. Another object of the present invention is to use the fennel extract to control the growth of duckweed, or kill duckweed, so as to protect the balance of aquatic ecology.

In order to achieve the above object, a kind of fennel extract of the present invention is prepared according to the following method, and the specific steps are as follows:

a. Wash the leaves, stems and roots of fresh fennel with water and air-dry them;

b. Cut the dried fennel leaves, stems and roots into pieces and put them in the container;

c. Add fennel and water to sterile water according to the weight ratio of 1:10~30;

d. Soak at room temperature for 2 to 4 days under dark conditions;

e. First remove the fennel fragments, and then filter them with a 1.2 μm cellulose acetate filter to obtain the fennel extract;

f. Store the fennel extract in the dark at 4°C.

The diameter of the fennel fragments in the above step b is preferably less than 5 mm.

The weight ratio of fennel to water in the above step c is preferably 1:10.

The temperature during soaking in the above step d is preferably 25°C±2°C, and the soaking time is 3 days.

An extract of fennel can be used to control the growth of duckweed, or to kill duckweed.

Traditional chemical herbicides have a good killing effect on duckweed, but their application in natural water bodies is limited due to their risks to the ecological environment and human health. Compared with traditional chemical herbicides, the fennel extract of the invention controls the growth of duckweed, or kills duckweed, has the advantages of being green and environmentally friendly, harmless to humans and animals, and has broad application prospects.

Description of drawings

Fig. 1 is a statistic diagram of duckweed petal number controlled by different doses of a fennel extract of the present invention to duckweed.

Fig. 2 is a picture of the control effect of a kind of fennel extract of the present invention on duckweed (a, control; b, 200 ml culture solution containing 50 ml extract solution on the 7th day after treatment).

Fig. 3 The diagram of oxidative damage of duckweed leaves after being treated with different doses of fennel extract of the present invention for 7 days (a, O ₂ ^- formation; b, MDA formation).

Fig. 4 a kind of fennel extract of the present invention different doses to leaf photosynthesis change diagram after duckweed treatment (a, the change of electron transfer rate rETR of photosynthetic system II; b, the change of original light energy conversion efficiency Fv/Fm of photosynthetic system II ).

Fig. 5 is a statistical diagram of duckweed petal number controlled by spraying different doses of an anise extract of the present invention on duckweed.

Detailed ways

Below in conjunction with accompanying drawing, the present invention is described further.

Embodiment one

A kind of fennel extract of the present invention is prepared according to the following method, and concrete steps are as follows:

a. Wash the leaves, stems and roots of fresh fennel with water and air-dry them;

b. Cut the dried fennel leaves, stems and roots into pieces and put them in the container;

c. Add fennel and water to sterile water according to the weight ratio of 1:10~30;

d. Soak at room temperature for 2 to 4 days under dark conditions;

e. First remove the fennel fragments, and then filter them with a 1.2 μm cellulose acetate filter to obtain the fennel extract;

f. Store the fennel extract in the dark at 4°C.

The diameter of the fennel pieces in the above step b is preferably less than 5mm.

The weight ratio of fennel to water in the above step c is preferably 1:10.

The temperature during soaking in the above step d is preferably 25°C±2°C, and the soaking time is 3 days.

Fennel extract can be used to control the growth of duckweed, or to kill duckweed.

Embodiment two

The fresh stems and leaves of fennel ( Foeniculum vulgare ) collected from a ditch in Fushan Village, Dianchi Lake, Kunming were washed 3-5 times with distilled water, placed in a ventilated place indoors, dried naturally, and cut into pieces with a diameter of less than 5 mm. Put it into a 2 L brown glass bottle, add water at a concentration of 100g FW/L, soak in the dark in an incubator at 25±2°C for 3 days, and pass through a 1.2 μm filter membrane to obtain plant water with a concentration of 100 mg FW/ml Extract, and store this extract in a sterilized brown reagent bottle at 4°C.

Experimental effect of controlling duckweed with fennel extract 1.

The fennel extract prepared in Example 2 was used in the experiment of inhibiting the growth of duckweed ( Lemna minor , collected in the water special demonstration project of the Institute of Hydrobiology, Chinese Academy of Sciences, Caohai, Dianchi, Kunming). The specific steps are as follows: a 250 ml beaker Add 100 ml of sterilized Hoagland's solution and different doses of fennel extract, 0, 5, 10, 20, 50 ml, and dilute to 200 ml with distilled water. Add 240 petals of duckweed that are clean, healthy and of the same size to each beaker, and cultivate them in a light incubator for 8 days (temperature 25±1°C, light intensity 20-25 μmol/m ² /s, light-dark ratio 12/12), adding evaporated water every day. During the implementation process, the number of duckweed petals, oxidative damage, and chlorophyll fluorescence characteristics were measured and counted. The experiment was set up in parallel with 3 groups. The implementation results are shown in Figures 1-3. After using the extract, the proliferation of duckweed leaves was significantly inhibited, and the growth of duckweed could be significantly inhibited after 1 day with 5 ml of extract in 200 ml of culture medium, and all duckweed died after 7 days after adding 50 ml of extract (attached figure 1). By measuring the O ₂ ^- concentration of duckweed leaves, the concentration of MDA and the efficiency of photosynthetic system II (figures 2 and 3), it shows that fennel extract can induce duckweed reactive oxygen species, cause lipid peroxidation of cell membranes, and inhibit chloroplasts of duckweed leaf cells Photosynthesis effect.

Experimental effect of controlling duckweed with fennel extract 2.

Since duckweed is a floating plant, the fennel extract prepared in Example 2 was sprayed on duckweed to study its inhibitory effect. In a 250ml beaker, add 200 ml of sterilized 1/2 Hoagland's solution and 240 petals of duckweed that are clean, healthy and of the same size, and place them in a light incubator for 6 days (temperature 25±1°C, light Strong 20~25 μmol/m ² /s, light to dark ratio 12/12). Spray 2 ml and 4 ml of 100 mg FW/ml fennel extract every day with a small sprayer as the treatment group, and spray distilled water as the control group. During the implementation process, count the number of duckweed petals every 1-2 days. The experiment was set up in parallel with 3 groups. The implementation results are shown in Figure 2. It shows that spraying 2 ml of the fennel extract every day can show an obvious inhibitory effect on duckweed on the 7th day, and spraying 4 ml can almost completely kill duckweed on the 7th day. The spraying method can effectively reduce the usage of extracting solution.

Preferred embodiments of the present invention have been described in detail above, but the present invention is not limited to the specific details of the above-mentioned embodiments. Within the scope of the technical concept of the present invention, various simple modifications can be made to the technical solutions of the present invention, and these simple modifications are all Belong to the protection scope of the present invention.

Claims (4)

1. a kind of application of fennel extracting solution in the growth of control duckweed or killing duckweed, it is characterised in that:

The fennel extracting solution is prepared as follows, the specific steps are as follows:

A, it is air-dried after the leaf, stem and root of fresh fennel being eluted with water；

B, fennel leaf, stem and the root shearing after air-drying are fragmentated, is put into container；

C, sterile water is added according to the weight ratio of 1:10~30 in fennel and water；

D, soaking at room temperature 2~4 days under dark condition；

E, first fennel fragment is pulled out, then with 1.2 μm of acetate fiber membrane filtrations, obtains fennel extracting solution；

F, fennel extracting solution is kept in dark place at 4 DEG C.

2. a kind of application of the fennel extracting solution according to claim 1 in the growth of control duckweed or killing duckweed, It is characterized in that, the diameter for preparing fennel fragment in extracting solution step b is more preferably less than 5 mm.

3. a kind of application of the fennel extracting solution according to claim 1 in the growth of control duckweed or killing duckweed, It is characterized in that, preparing the weight ratio of fennel and water in extracting solution step c is 1:10.

4. a kind of application of the fennel extracting solution according to claim 1 in the growth of control duckweed or killing duckweed, It is characterized in that, preparing temperature when impregnating in extracting solution step d is 25 DEG C ± 2 DEG C, soaking time is 3 days.