CN113439623A

CN113439623A - Method for improving leaf vegetable yield and selenium content based on regulation and control of root system microorganisms

Info

Publication number: CN113439623A
Application number: CN202110645488.3A
Authority: CN
Inventors: 王震宇; 王传洗; 乐乐; 陈菲然; 曹雪松
Original assignee: Jiangnan University
Current assignee: Jiangnan University
Priority date: 2021-06-10
Filing date: 2021-06-10
Publication date: 2021-09-28

Abstract

The invention discloses a method for improving leaf vegetable yield and selenium content based on regulation and control of root system microorganisms, and belongs to the technical field of nano agriculture. The method comprises the following steps: applying selenium nano fertilizer to the roots of crops; the selenium nano fertilizer is a zero-valent Se nano material, the size of the selenium nano fertilizer is 10-90 nm, the selenium nano fertilizer is applied in the form of selenium nano particle solution, the applied concentration is 1-20 mg/L, and the applied volume of the selenium nano fertilizer is 50-150 mL/plant. The method can obviously improve the microbial community of the root system of the leaf vegetables; the Se content in the leaf vegetable plants is obviously improved; the photosynthesis of the leaf vegetable plants is obviously improved, and the yield of the leaf vegetable plants is increased; the content of trace elements in the leaf vegetable plants is obviously improved.

Description

Method for improving leaf vegetable yield and selenium content based on regulation and control of root system microorganisms

Technical Field

The invention relates to a method for improving leaf vegetable yield and selenium content based on regulation and control of root system microorganisms, and belongs to the technical field of nano agriculture.

Background

Selenium (Se) is a beneficial element for plants, and organic form Se in plants is an important source for supplementing Se for human beings. Research shows that Se is a constituent element of glutathione peroxidase in a human body and an important component for maintaining the activity of various enzymes, and has the functions of resisting oxidation and cancer, improving immunity and the like in the human body. However, Se deficiency in the diet of the population in many countries of the world remains a common problem, and the production of Se-rich foods by the application of inorganic Se fertilizers is currently an effective solution to human Se deficiency.

Leaf vegetables occupy an important position in the dietary structure of people. In China, each person is recommended to consume 300-500 g of leaf vegetable food every day. Moreover, in China, the planting area of leaf vegetables is 3 hundred million acres each year; the yield is more than 7 hundred million tons. Therefore, the Se-rich technology in the leaf vegetable food is developed, the national health index can be improved, and the quality and the economic value of the leaf vegetable food can be improved.

In recent years, Se nanomaterials (Se NMs) have high activity and have gained increasing attention and acceptance for use as Se fertilizers. Research reports indicate that the Se NMs can promote the formation of plant callus organs and the growth of root systems, increase the photosynthesis and yield of crops, and improve the nutritional quality (Se content, soluble sugar, soluble protein, antioxidant enzyme activity and the like) of the crops.

Rhizosphere microorganisms play a key role in increasing nutrient utilization and promoting plant growth. For example, the symbiotic relationship between plants and nitrogen-fixing bacteria can convert nitrogen in the atmosphere into ammonium nitrogen, and the utilization efficiency of the plants on N is improved. The phosphorus-dissolving bacteria can excrete organic acids and increase the solubility of the precipitated phosphorus, thereby increasing the utilization of phosphorus. Research has shown that nutrients such as iron (Fe), magnesium (Mg) and phosphorus can improve the photosystem and promote photosynthesis; the carbohydrate formed by photosynthesis can provide 11% to 40% of carbon source for the microorganism, and further promote the growth of the microorganism.

Disclosure of Invention

[ problem ] to

At present, the conditions under which Se NMs can stably and efficiently promote the growth of crops, improve the yield of the crops and increase the Se content in the crops are not determined. Factors such as the application amount, the particle size and the application mode of the Se NMs influence the accumulation of Se in crops; it is not clear whether Se NMs can increase the absorption efficiency of soil nutrients and improve crop photosynthesis by regulating and controlling the microbial community of crop root systems, so that the aim of increasing the selenium yield is achieved.

[ solution ]

In order to solve at least one problem, the invention provides a method for improving the yield and Se content of leaf vegetables, which defines the factors such as particle size, application amount, application period, application mode and the like of Se nano fertilizer for producing Se-rich leaf vegetables, defines the key action of root microorganisms, increases the absorption efficiency of soil nutrients, improves crop photosynthesis, and achieves the aim of increasing the selenium yield. The invention applies the synthesized Se nano fertilizer to the roots of the leaf vegetable plants in the seedling stage, can obviously improve the microbial community structure of soil, promote the absorption of nutrients, improve the photosynthesis of crops, increase the yield and simultaneously promote the enrichment of Se in the leaf vegetable plants.

The first purpose of the invention is to provide a method for regulating and controlling the microorganisms of crop roots, which is to apply selenium nano fertilizer to the roots of crops.

In one embodiment of the invention, the selenium nano-fertilizer is a zero-valent Se nano-material, and the size of the selenium nano-fertilizer is 10-90 nm, and more preferably 30-70 nm.

In one embodiment of the present invention, the selenium nanofertilizer is applied in the form of selenium nanoparticle solution, and the applied concentration is 1-20 mg/L, and more preferably 5-15 mg/L.

In one embodiment of the invention, the crop is leafy vegetables including one of chinese cabbage, spinach, celery, rape, coriander (coriander), lettuce, water spinach (water spinach), agaric, shepherd's purse, amaranth, garland chrysanthemum, wuta-tsai, fennel, leek, garlic sprout, pea sprout, chicory sprout, buckwheat sprout, radish sprout, chayote sprout.

In one embodiment of the present invention, the selenium nanofertilizer is applied in a volume of 50 to 150mL per plant, and more preferably 80 to 120mL per plant.

In one embodiment of the invention, the application period of the selenium nano fertilizer is the seedling period of the leaf vegetable plant, in particular the period of two leaves and one heart or four leaves and one heart of the plant.

The second purpose of the invention is to provide a method for improving the yield of leaf vegetables and the selenium content based on the regulation of root microorganisms, wherein the method is the method for regulating the root microorganisms of crops.

A third object of the invention is the use of the method according to the invention in the field of agriculture.

The fourth purpose of the invention is to provide a method for cultivating the leaf vegetables with high selenium content, which is to apply selenium nano fertilizer to the roots of the leaf vegetables for cultivation; wherein the selenium nano fertilizer is a zero-valent Se nano material with the size of 10-90 nm; the selenium nano fertilizer is applied in the form of selenium nano particle solution, and the applied concentration is 1-20 mg/L; the application volume of the selenium nano fertilizer is 50-150 mL per plant.

In one embodiment of the invention, the leaf vegetable is one of canola, Chinese cabbage or lettuce.

[ advantageous effects ]

The method can obviously improve the microbial community of the root system of the leaf vegetables; the Se content in the leaf vegetable plants is obviously improved by more than 3 times compared with the plants without the selenium fertilizer; the photosynthesis of the leaf vegetable plants is obviously improved by more than 12 percent compared with the plants without the selenium fertilizer; the yield is increased by over 17 percent compared with the plant without the selenium fertilizer; (ii) a The trace element content of the leaf vegetable plants is obviously improved, and the magnesium element is improved by more than 24 percent compared with the plants without the selenium fertilizer; the calcium element is increased by more than 16 percent relative to the plant without the selenium fertilizer; the iron element is increased by more than 2 percent relative to the plant without the selenium fertilizer.

Drawings

FIG. 1 is a standard curve of selenium content.

FIG. 2 is a standard curve of magnesium content.

FIG. 3 is a standard curve of iron content.

FIG. 4 is a standard curve of calcium content.

Fig. 5 is a TEM photograph of the Se nanomaterial in example 1.

FIG. 6 shows the Se content (with and without Se) in Brassica napus in example 1 and comparative example 1.

FIG. 7 shows the net photosynthetic rates (with and without Se) in Brassica napus in example 1 and comparative example 1.

FIG. 8 shows the yields of Brassica napus (with and without Se) in example 1 and comparative example 1.

FIG. 9 shows the magnesium (Mg) content (with and without Se) of Brassica napus in example 1 and comparative example 1.

FIG. 10 shows the iron (Fe) contents (with and without Se) of Brassica napus in example 1 and comparative example 1.

FIG. 11 shows the calcium (Ca) content (with and without Se) of Brassica napus in example 1 and comparative example 1.

FIG. 12 shows the difference between soil microorganisms (Se added and Se not added) in example 1 and comparative example 1.

Detailed Description

The following description of the preferred embodiments of the present invention is provided for the purpose of better illustrating the invention and is not intended to limit the invention thereto.

The test method comprises the following steps:

1. testing of trace elements (selenium, magnesium, iron, calcium):

the determination of the content of the trace elements is completed by two steps: 1. digesting the sample by using a microwave digestion instrument; 2. measured using inductively coupled plasma mass spectrometry (ICP-MS).

The method comprises the following specific steps: 1. sampling and pretreatment: the air-dried plant samples were ground and sieved (60 mesh), 5 uniformly mixed samples (25 mg/sample) were weighed for each treatment group and placed in digestion tubes, equivalent nitric acid was added, and the digestion tubes were sealed and placed in a microwave digestion apparatus for digestion. After digestion is completed, filtering the sample to a constant volume of 50mL, and then analyzing and testing by using ICP-MS; 2. preparation of standard curve solution: 1mL of the standard mixture (1000mg/L) was added to 100mL of ultrapure water to prepare a 10mg/L mixed standard mother liquor, and the mother liquor was diluted to five concentration-gradient standards: 0. 100, 200, 500, 1000 and 10000 mug/L.

The results of the standard curves of selenium, magnesium, iron and calcium are shown in fig. 1-4, wherein y is the content of elements (microgram/kilogram, microgram/Kg), and x is the GPS signal value.

2. Testing of net photosynthetic rate: the net photosynthetic rate of canola leaf blades was tested using a portable photosynthesizer (CIRAS-3portable gas exchange system, Hansatech, USA).

3. And (3) testing yield: the stem base of the plant is cut off, and the fresh weight of the upper part of the ground of the plant is weighed by a balance with one percent precision. And then putting the weighed plants into an oven for fixation for half an hour at 105 ℃, drying for 72 hours at 75 ℃, and weighing the dry weight of the overground part by using a balance with the precision of one thousandth.

4. Testing of the differences of soil microorganisms: tested using 16S rRNA microbiological assay technology.

Example 1

A method for improving leaf vegetable yield and selenium content based on regulation and control of root system microorganisms comprises the following steps:

(1) sterilizing rape seeds from agricultural academy of sciences of Jiangsu province in 5% sodium hypochlorite solution for 10 min, and then washing with deionized water for 3 times for sterilization;

(2) soaking the seeds in deionized water for 4 hours after the disinfection is finished, then transferring the seeds into a soil culture vessel of 5.0kg, and spraying water regularly every day;

(3) when the seedling grows out and reaches the period of two leaves and one heart, 100mL of Se fertilizer (with the grain diameter of 60nm) solution of 5mg/L is added into the root; the cultivation is continued, and the small rape is harvested after 60 days.

Comparative example 1(CK group)

The Se fertilizer (with the particle size of 60nm) solution in the step (3) in the example 1 is replaced by water, the rest is kept the same as the example 1, and the rape seeds are harvested after 60 days.

And (3) carrying out performance test on the received rape, wherein the test result is as follows: the Se content in the leaves of example 1 is increased by 3.38 times compared with that of comparative example 1 to reach 328 micrograms/Kg (FIG. 6), the net photosynthetic rate is increased by 16.67% (FIG. 7), the yield is increased by 19.78% (FIG. 8), and the trace elements of magnesium, iron and calcium in the vegetable leaves are respectively increased by 24.23% (FIG. 9), 2.53% (FIG. 10) and 16.58% (FIG. 11).

The root soil microorganisms were tested for changes (fig. 12), and as can be seen from fig. 12: proteobacteria (Proteobacteria) and Bacteroides (Bacteroides) were significantly increased compared to control example 1. There are many Plant Growth-promoting bacteria (Plant Growth promoter Rhizobacteria) in the phylum Proteus, which play an important role in promoting Plant Growth. On the other hand, the beneficial microorganisms of the plants can also promote the plants to absorb selenium, and enhance the selenium-rich effect of the plants. In addition, phyla can degrade high molecular weight compounds such as proteins and polysaccharides, which may have a positive effect on sugar and organic acid metabolism in soil.

Example 2

The Se fertilizer in the example 1 is respectively adjusted to 40nm Se particles, 1 μm Se particles and 5mg/L sodium selenate solution, other parameters are kept consistent with those in the example 1, and the small rape is harvested after 60 days.

The test results are given in table 1 below:

table 1 test results of example 2

Example 3

Adjusting the application amount of the Se fertilizer in the embodiment 1, wherein the concentration is 5mg/L, and the application volume is adjusted to 50-150 mL; other parameters were kept the same as in example 1, and the cole was harvested after 60 days.

The test results are given in table 2 below:

table 2 test results of example 3

Example 4

The leaf vegetable types in the adjustment example 1 were: chinese cabbage, lettuce, spinach, and leek; other parameters were kept the same as in example 1, and the cole was harvested after 60 days.

The test results are given in table 3 below:

table 3 test results of example 4

Comparative example 2

The Se fertilizer application mode in the example 1 is adjusted to be water-based culture, specifically, the Se fertilizer with the particle size of 60nm is added into the standard Hoagland nutrient solution, the concentration is 5mg/L, other parameters are consistent with those in the example 1, and the small rape is harvested after 60 days.

Comparative example 3

The Se fertilizer application mode in the example 1 is adjusted to be foliar fertilization, specifically, 100mL of Se fertilizer (with the grain diameter of 60nm) solution of 5mg/L is sprayed on the leaf surfaces of seedlings, other parameters are kept consistent with those in the example 1, and the small rapes are harvested after 60 days.

Comparative example 4

The soil in the example 1 is changed into sterilized soil, other parameters are kept consistent with those in the example 1, and the small rape is harvested after 60 days.

The test results are shown in table 4:

TABLE 4 test results of comparative examples 1 to 4

Although the present invention has been described with reference to the preferred embodiments, it should be understood that various changes and modifications can be made therein by those skilled in the art without departing from the spirit and scope of the invention as defined in the appended claims.

Claims

1. A method for regulating and controlling microbes in crop roots is characterized in that selenium nano-fertilizer is applied to the crop roots.

2. The method according to claim 1, wherein the selenium nanofertilizer is a zero-valent Se nanomaterial with a size of 10-90 nm.

3. The method of claim 1 or 2, wherein the selenium nanofertilizer is applied in the form of a selenium nanoparticle solution at a concentration of 1-20 mg/L.

4. The method according to any one of claims 1 to 3, wherein the crop is a leafy vegetable comprising one of Chinese cabbage, common head cabbage, spinach, celery, rape, coriander (coriander), lettuce, swamp spinach, black spinach, shepherd's purse, amaranth, garland chrysanthemum, wuta-tsai, fennel, leek, garlic sprout, pea sprout, chicory sprout, buckwheat sprout, radish sprout, chayote sprout.

5. The method of any one of claims 1 to 4, wherein the selenium nanofertilizer is applied in a volume of 50 to 150mL per strain.

6. The method according to any one of claims 1 to 5, wherein the selenium nanofertilizer is applied at the seedling stage of a leaf vegetable plant, in particular at the stage of two leaves and one heart or four leaves and one heart of the plant.

7. A method for improving leaf vegetable yield and selenium content based on root microorganism regulation, which is characterized in that the method for regulating the root microorganism of crops is adopted in any one of claims 1 to 6.

8. The method for regulating and controlling the microorganisms of the crop root system as claimed in any one of claims 1 to 6, which is applied to the agricultural field.

9. A method for cultivating leaf vegetables with high selenium content is characterized in that selenium nano-fertilizer is applied to the roots of the leaf vegetables for cultivation; wherein the selenium nano fertilizer is a zero-valent Se nano material with the size of 10-90 nm; the selenium nano fertilizer is applied in the form of selenium nano particle solution, and the applied concentration is 1-20 mg/L; the application volume of the selenium nano fertilizer is 50-150 mL per plant.

10. The method of claim 9, wherein the leaf vegetable is one of canola, chinese cabbage or lettuce.