A high-selenium tuckahoe and a culture method thereof

Abstract

The application discloses high-selenium Drabbea japonica and a culture method thereof. The culture method comprises the following steps: culturing Drabbea japonica seedlings, applying a selenium-containing nutrient solution or a selenium-containing fertilizer after 15 days, and then regularly supplementally applying the selenium-containing nutrient solution or the selenium-containing fertilizer until harvesting; after the first application of the selenium-containing nutrient solution or the selenium-containing fertilizer, a selenium absorption promoter is sprayed every 7-10 days until harvesting. The selenium absorption promoter is a suitable amount of zeatin, abscisic acid or spermidine. In the cultivation process, by adding a suitable compound selenium and strictly limiting the concentration of selenium, high-selenium Drabbea japonica plants can be obtained, and the edible value of the Drabbea japonica plants can be greatly improved. In addition, by adding a suitable amount of zeatin, abscisic acid or spermidine in the cultivation process, the selenium content in the roots of the Drabbea japonica can be greatly improved, and the nutritional value and medicinal value of the Drabbea japonica are greatly improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of agricultural cultivation technology, and particularly relates to a high-selenium Aster subulatus and a culture method thereof. BACKGROUND

[0002] Selenium (Se) is one of the important trace elements necessary for human and plant growth, and plays a positive role in promoting plant growth, enhancing stress resistance, resisting diseases and regulating the quality of agricultural products. Appropriate Se can remove free radicals in the body and has beneficial physiological effects on humans and animals, such as preventing cancer, resisting tumors, resisting aging and enhancing immunity. However, excessive Se can have negative effects on the body, and excessive Se supplementation can cause Se poisoning and other hazards. Research has found that inorganic Se is highly toxic and is not easily absorbed and utilized by humans and animals, while organic Se, as an important Se source, can be efficiently utilized by the body and plays an important role in human and animal life activities. Plants, as an important organism, can absorb inorganic Se and assimilate it into organic Se. Organic Se exists mainly in the form of macromolecular Se and small-molecule Se compounds in the form of selenium amino acids and their derivatives. These active organic Se in plants can be used as an effective Se source for humans and animals. Therefore, Se-rich plants with large biomass, easy reproduction and fast growth are an important way for animals to supplement Se, and can be used as a safe and effective dietary organic Se source. Further screening of Se-rich plants is of great significance to humans.

[0003] In recent years, Se-enriched and Se-hyperaccumulating plants that have been studied more include Astragalus membranaceus, Pterocypsela scaber, Nymphoides peltatum, Dipsacus asper and King Wing Feather. Aster subulatus Michx., also known as scissors, white chrysanthemum, earth-penny, nine-dragon arrow and drill-shaped aster, is a plant of the Asteraceae family. It grows in humid saline soils and benefits from the unique tropical and subtropical climate conditions in the Guangxi Zhuang Autonomous Region. Aster subulatus Michx. can grow and reproduce throughout the year and is widely distributed in the Guangxi Zhuang Autonomous Region. The whole plant of Aster subulatus Michx. can be used as medicine, is cool in nature and sweet and bitter in taste, has the functions of cooling blood, stopping bleeding and clearing heat and detoxifying, and is used to treat carbuncles and eczema. The tender seedlings and stems and leaves of Aster subulatus Michx. can be used as wild vegetables and are rich in nutrients, making them a wild vegetable with great development prospects. The inventors have found in previous studies that Aster subulatus Michx. is widely distributed, easy to survive, grows rapidly, has stable physiological characteristics, relies on seed reproduction, has a large amount of seeds and a large biomass. However, there are few reports on the growth changes and Se enrichment and transport characteristics of Aster subulatus Michx. under the action of Se, especially under laboratory controlled conditions. The Se-enriched parts of different plants are not the same, and the Se enrichment rules are also different. It is not clear how to concentrate organic selenium in the roots of Aster subulatus Michx. to obtain high-selenium Aster subulatus Michx. and improve the nutritional value and medicinal value of Aster subulatus Michx. Therefore, it is particularly necessary to study a nutrient solution and a culture method for high-selenium Aster subulatus Michx. SUMMARY

[0004] The present application overcomes the technical problem in the prior art that it is difficult to obtain high Se-enriched Draba leaf sunflower, and provides a high Se-enriched Draba leaf sunflower and a culture method thereof.

[0005] To solve the above problems, the present application adopts the following technical solutions:

[0006] The culture method of the high Se-enriched Draba leaf sunflower comprises the following steps: culturing Draba leaf sunflower seedlings, applying a selenium-containing nutrient solution or a selenium-containing fertilizer after 15 days of culture, and then regularly supplementing the application of the selenium-containing nutrient solution or the selenium-containing fertilizer until harvesting.

[0007] Further, after the first application of the selenium-containing nutrient solution or the selenium-containing fertilizer, a selenium absorption promoter is sprayed every 7-10 days until harvesting; the selenium absorption promoter is 0.5 mg / L corn hormone or 0.5 mg / L-1.0 mg / L abscisic acid or 50 mg / L spermidine.

[0008] Further, the selenium-containing nutrient solution is composed of the following components:

[0009] KNO3 2.0-4.0 mmol / L;

[0010] Ca(NO3)2·4H2O 0.5-1 mmol / L;

[0011] MgSO4·7H2O 0.2-0.5 mmol / L;

[0012] KH2PO4 0.01-0.1 mmol / L;

[0013] H3BO3 10-12 μmol / L;

[0014] MnCl2·4H2O 2.0-5 μmol / L;

[0015] ZnSO4·7H2O 0.3-0.5 μmol / L;

[0016] CuSO4·5H2O 0.20-0.40 μmmol / L;

[0017] (NH4)2MoO4 0.1-0.2 μmmol / L;

[0018] Fe-EDTA 20-40 μmmol / L;

[0019] Selenium element: sodium selenite 10-20 mg / L.

[0020] Further, the selenium element is sodium selenite 10 mg / L.

[0021] Further, the selenium-containing nutrient solution needs to be adjusted to pH 5.5-6.0 with 0.1 mol / L NaOH or 0.1 mol / L HCl before use.

[0022] Another object of the present application is also to protect the high-selenium T. drakei obtained by the above-mentioned culture method.

[0023] Compared with the prior art, the present application has the following beneficial effects:

[0024] (1) The present application adopts different selenium forms for multi-research, and it is found that different selenium elements of compounds have significant different effects on T. drakei. The present application adds 10-20 mg / L of sodium selenite in the existing nutrient solution formula, which is not only beneficial to increase the plant height of T. drakei, but also beneficial to increase the total fresh weight and the above-ground fresh weight of T. drakei. Through selenium content detection of different parts, it is found that the inorganic Se and organic Se contents of the roots, stems and leaves of T. drakei obtained by adding 10-20 mg / L of sodium selenite are higher than those obtained by adding sodium selenate and other concentrations of sodium selenite. Especially when the amount of added sodium selenite is 10 mg / L, the selenium content of the stems and leaves of T. drakei is the highest, and the selenium enrichment is the best.

[0025] (2) The present application is found through the selenium-enriched culture research without adding selenium absorption promoters that the Se contents of the roots and leaves of T. drakei are 150.02 mg / kg and 124.06 mg / kg respectively, which reaches the standard of selenium-enriched plants (the Se content standard range value of Se-enriched plants is 100-1000 mg / kg).

[0026] (3) The present application adds appropriate amounts of zeatin, spermidine and abscisic acid in the nutrient solution during the culture of T. drakei, which can greatly improve the selenium content of the roots of T. drakei, and greatly improve the growth and yield of T. drakei, and greatly improve the medicinal value and nutritional value of T. drakei. BRIEF DESCRIPTION OF DRAWINGS

[0027] Figure 1 Effects of different concentrations of sodium selenite and sodium selenate on the plant height of T. drakei;

[0028] Figure 2 Effects of different concentrations of sodium selenite on the fresh weight of T. drakei;

[0029] Figure 3 Effects of different concentrations of sodium selenate on the fresh weight of T. drakei. DETAILED DESCRIPTION

[0030] The present application will be further described below in combination with examples and tests.

[0031] Embodiment 1

[0032] A culture method of high selenium-rich Dracula, comprising the following steps: culturing Dracula seedlings, applying a selenium-containing nutrient solution after 15 days of culture, and then regularly supplementing the application of the selenium-containing nutrient solution until harvesting. The selenium-containing nutrient solution is composed of the following components:

[0033] KNO3 4.0mmol / L;

[0034] Ca(NO3)2·4H2O 1mmol / L;

[0035] MgSO4·7H2O 0.5mmol / L;

[0036] KH2PO4 0.1mmol / L;

[0037] H3BO3 12μmol / L;

[0038] MnCl2·4H2O 5μmol / L;

[0039] ZnSO4·7H2O 0.5μmol / L;

[0040] CuSO4·5H2O 0.40μmmol / L;

[0041] (NH4)2MoO4 0.2μmmol / L;

[0042] Fe-EDTA 40μmmol / L;

[0043] Selenium element: sodium selenite 20mg / L.

[0044] Embodiment 2

[0045] A culture method of high selenium-rich Dracula, comprising the following steps: culturing Dracula seedlings, applying a selenium-containing nutrient solution after 15 days of culture, and then regularly supplementing the application of the selenium-containing nutrient solution until harvesting. The selenium-containing nutrient solution is composed of the following components:

[0046] KNO3 2.0mmol / L;

[0047] Ca(NO3)2·4H2O 0.5mmol / L;

[0048] MgSO4·7H2O 0.2mmol / L;

[0049] KH2PO4 0.01mmol / L;

[0050] H3BO3 10μmol / L;

[0051] MnC12·4H2O 2.0 μmol / L;

[0052] ZnSO4·7H2O 0.3 μmol / L;

[0053] CuSO4.5H2O 0.20 μmmol / L;

[0054] (NH4)2MoO4 0.1 μmmol / L;

[0055] Fe-EDTA 20 μmmol / L;

[0056] Selenium element: sodium selenite 10 mg / L.

[0057] Example 3

[0058] A culture method of a high-selenium Drimia indica includes the following steps: culturing Drimia indica seedlings, applying a selenium-containing nutrient solution after 15 days of culture, and then regularly supplementing the selenium-containing nutrient solution until harvesting. The selenium-containing nutrient solution is composed of the following components:

[0059] KNO3 3.0 mmol / L;

[0060] Ca(N03)2·4H2O 0.8 mmol / L;

[0061] MgSO4·7H2O 0.4 mmol / L;

[0062] KH2PO4 0.05 mmol / L;

[0063] H3BO3 11 μmol / L;

[0064] MnC12·4H2O 4 μmol / L;

[0065] ZnSO4·7H2O 0.4 μmol / L;

[0066] CuSO4.5H2O 0.30 μmmol / L;

[0067] (NH4)2MoO4 0.15 μmmol / L;

[0068] Fe-EDTA 30 μmmol / L;

[0069] Selenium element: sodium selenite 10 mg / L.

[0070] Example 4

[0071] A high-selenium Drimyodoris cultivation method, comprising the following steps: cultivating Drimyodoris seedlings, applying a selenium-containing nutrient solution after 15 days of cultivation, and then regularly supplementing the application of the selenium-containing nutrient solution until harvesting. After the first application of the selenium-containing nutrient solution, a selenium absorption promoter is sprayed every 7 days until harvesting; the selenium absorption promoter is 0.5 mg / L corn hormone. The selenium-containing nutrient solution is the same as in Example 2.

[0072] Example 5

[0073] A high-selenium Drimyodoris cultivation method, comprising the following steps: cultivating Drimyodoris seedlings, applying a selenium-containing nutrient solution after 15 days of cultivation, and then regularly supplementing the application of the selenium-containing nutrient solution until harvesting. After the first application of the selenium-containing nutrient solution, a selenium absorption promoter is sprayed every 10 days until harvesting; the selenium absorption promoter is 0.2 mg / L abscisic acid. The selenium-containing nutrient solution is the same as in Example 2.

[0074] Example 6

[0075] A high-selenium Drimyodoris cultivation method, comprising the following steps: cultivating Drimyodoris seedlings, applying a selenium-containing nutrient solution after 15 days of cultivation, and then regularly supplementing the application of the selenium-containing nutrient solution until harvesting. After the first application of the selenium-containing nutrient solution, a selenium absorption promoter is sprayed every 8 days until harvesting; the selenium absorption promoter is 50 mg / L spermidine. The selenium-containing nutrient solution is the same as in Example 2.

[0076] In order to illustrate the technical effect of the present application, the following two experiments were conducted:

[0077] Experiment 1: Drimyodoris absorption effect of different compound selenium

[0078] 1. Experimental method:

[0079] In the glass net, the seedlings of T. drakei were cultured by using the nutrient solution of Example 1 without selenium element. The seedlings of T. drakei were obtained by planting the seeds of T. drakei in soil without Se after ethanol disinfection. The seedlings with 6 complete leaves and uniform growth were selected, the roots were washed with ultrapure water, and the seedlings were transplanted into plastic buckets with a diameter of 16 cm, a height of 11 cm, and a bottom diameter of 9 cm. Each bucket contained 1.0 kg of sand, and 3 seedlings of T. drakei were planted in each bucket. 0.5 L of the nutrient solution of Example 1 without selenium element was applied, and then 0.5 L of the nutrient solution was supplemented every 2 days to maintain the growth of T. drakei. After 15 days of culture, different concentrations of Se-containing nutrient solution were applied, with 3 repetitions for each treatment. The experimental design scheme was 2 kinds of exogenous Se and 7 different Se concentrations. The Se concentration in the nutrient solution of Example 1 was designed as 0 mg / L (no Se, CK), 10 mg / L (Na2SeO3), 20 mg / L (Na2SeO3), 40 mg / L (Na2SeO3), 10 mg / L (Na2SeO4·10H2O), 20 mg / L (Na2SeO4·10H2O), and 40 mg / L (Na2SeO4·10H2O), respectively. The pH of the nutrient solution was adjusted to about 5.6 with 0.1 mol / L NaOH or 0.1 mol / L HCl. 0.5 L of the nutrient solution with different Se concentrations was applied for the first time, and then 0.5 L of the nutrient solution was applied every 14 days. During the culture period, ultrapure water was supplemented at irregular intervals to keep the quartz sand moist and maintain the growth of T. drakei. After 42 days, the plant height of T. drakei in each treatment was measured, and the plants were harvested for standby.

[0080] 2Sample preparation and analysis method

[0081] After the treatment, the whole plant of T. drakei was taken out, the root system was removed, and the roots were repeatedly washed clean with flowing tap water. The roots were soaked in deionized water for 20 min to remove the adsorbed Se on the surface, and then repeatedly washed clean with deionized water and wiped clean with absorbent paper. The T. drakei was divided into roots, stems, and leaves, and was killed in an oven at 105℃ for 30 min, and then dried at 65℃ to constant weight. After the dry weight was measured, the roots, stems, and leaves were respectively crushed through a 100-mesh sieve with a stainless steel crusher, and were prepared for standby.

[0082] The plant height of T. drakei was determined by direct determination method, the biomass of T. drakei was determined by oven drying constant weight method, the total selenium content of T. drakei roots, stems, and leaves was determined by GB / T5009.93 “Determination of selenium in food (first method hydrogenated atom fluorescence spectrometry)”, the inorganic Se content of T. drakei roots, stems, and leaves was determined by DB 3301 / T 117-2007 “Determination of organic selenium and inorganic selenium content in rice by atomic fluorescence spectrometry”, and the organic Se content was obtained by deducting the inorganic Se content from the total Se content.

[0083] Experimental data were processed using Excel 2010, and significance analysis was performed using SPSS 18.1.

[0084] 3. Experimental Results and Analysis:

[0085] 3.1 Effects of different concentrations of sodium selenite and sodium selenate on the plant height of *Aster tataricus*

[0086] The effects of different concentrations of sodium selenite and sodium selenate on the plant height of *Aster tataricus* are shown in the figure. Figure 1 ,Depend on Figure 1 It was found that when sodium selenite was used as the Se source, there was no significant difference in plant height between the sodium selenite treatment group and the control group (P<0.05). However, the plant height of Aster tataricus treated with sodium selenite concentrations of 10 mg / L and 20 mg / L was higher than that of the control group, increasing by 11.46% and 2.19% respectively. When the sodium selenite concentration was 40 mg / L, the plant height of Aster tataricus was the lowest, significantly lower than that of the 10 mg / L Se concentration treatment (P<0.05), and 20.24% lower than that of the 10 mg / L Se concentration treatment. When sodium selenate was used as the Se source, the plant height of *Aster tataricus* was reduced by 3.72%–12.81% in all treatment groups with different sodium selenate concentrations compared to the control (CK). The lowest plant height was observed at a concentration of 40 mg / L Se, significantly lower than the CK by 12.81% (P<0.05) and significantly lower than the 10 mg / L Se concentration by 9.44% (P<0.05). In conclusion, the addition of sodium selenite at concentrations of 10 mg / L and 20 mg / L is beneficial for increasing the plant height of *Aster tataricus*, but concentrations exceeding 10 mg / L inhibited plant growth. At the same concentration, the plant height of *Aster tataricus* treated with sodium selenite was lower than that treated with sodium selenate.

[0087] 3.2 Effects of different concentrations of sodium selenite and sodium selenate on the fresh weight of Aster tataricus under the influence of different concentrations of sodium selenite and sodium selenate.

[0088] The effect of different concentrations of sodium selenite on the fresh weight of Aster tataricus is shown in the figure. Figure 2 The effect of different concentrations of sodium selenate on the fresh weight of Aster tataricus is shown in the figure. Figure 3 .Depend on Figure 2It was found that when sodium selenite was used as the Se source, there were no significant differences in the fresh weight of the aboveground parts and roots of *Aster tataricus* at different concentrations (P<0.05). However, the total fresh weight and aboveground fresh weight of *Aster tataricus* were highest at a Se concentration of 10 mg / L, increasing by 5.99% and 10.09% respectively compared to the control (CK). The total fresh weight, aboveground fresh weight, and root fresh weight of *Aster tataricus* were lowest at a Se concentration of 40 mg / L, decreasing by 33.52%, 37.70%, and 26.89% respectively compared to the control (CK). There was a significant difference in the total fresh weight of the aboveground parts of *Aster tataricus* between the 10 mg / L and 40 mg / L Se concentration treatment groups, while there were no significant differences among the other treatment groups (P<0.05). Figure 3 It was found that when sodium selenate was used as the Se source, there were no significant differences in the total fresh weight, aboveground fresh weight, and root fresh weight of *Aster tataricus* at different concentrations (P<0.05). However, the total fresh weight and aboveground fresh weight of *Aster tataricus* were highest at a Se concentration of 20 mg / L, increasing by 4.14% and 12.30% compared to the control (CK), respectively. The total fresh weight, aboveground fresh weight, and root fresh weight of *Aster tataricus* were lowest at a Se concentration of 40 mg / L, decreasing by 13.30%, 18.38%, and 10.09% compared to the control (CK), respectively. The addition of sodium selenite at concentrations of 10 mg / L and 20 mg / L was beneficial in increasing the accumulation of aboveground and total fresh weight of *Aster tataricus*, while other concentrations of sodium selenite and selenate inhibited the growth of *Aster tataricus* plants. The root fresh weight of *Aster tataricus* in all treatments was lower than that in the control (CK).

[0089] 3.3 Effects of different concentrations of sodium selenite and sodium selenate on Se content in the roots, stems, and leaves of *Aster tataricus*

[0090] The Se content in the roots of *Aster tataricus* under different concentrations of sodium selenite and sodium selenate is shown in Table 1; the Se content in the stems of *Aster tataricus* under different concentrations of sodium selenite and sodium selenate is shown in Table 2; and the Se content in the leaves of *Aster tataricus* under different concentrations of sodium selenite and sodium selenate is shown in Table 3.

[0091] Table 1. Se content in the roots of *Aster tataricus* under the influence of different concentrations of sodium selenite and sodium selenate.

[0092]

[0093] Note: Different lowercase letters in the same column indicate significant differences between treatment groups (P<0.05).

[0094] Table 2. Se content in the stems of *Aster tataricus* under the influence of different concentrations of sodium selenite and sodium selenate.

[0095]

[0096] Note: Different lowercase letters in the same column indicate significant differences between treatment groups (P<0.05).

[0097] Table 3. Se content in leaves of *Aster tataricus* under the influence of different concentrations of sodium selenite and sodium selenate.

[0098]

[0099]

[0100] Note: Different lowercase letters in the same column indicate significant differences between treatment groups (P<0.05).

[0101] As shown in Tables 1, 2, and 3, with increasing Se concentration, the Se content in the roots, stems, and leaves of *Aster tataricus* treated with sodium selenite all showed an increasing trend, with significant differences among treatments (P<0.05). The Se content in the roots of *Aster tataricus* treated with sodium selenite showed a trend of first increasing and then decreasing, while the Se content in the stems showed a trend of first decreasing and then increasing. However, the Se content in the leaves showed a gradual increasing trend, with significant differences among treatments in the leaves (P<0.05). In all treatments with exogenous Se addition, the Se content in *Aster tataricus* showed the order of roots > leaves > stems. Furthermore, the Se content in the roots, stems, and leaves of *Aster tataricus* was analyzed using sodium selenite and sodium selenate at the same concentrations. The results showed that, except for the 10 mg / L treatment, the Se content in the roots, stems, and leaves of *Aster tataricus* treated with sodium selenite was significantly higher than that treated with sodium selenate. At a concentration of 40 mg / L, the sodium selenite treatment resulted in the highest Se content in the roots, stems, and leaves, at 612.33 mg / kg, 117.40 mg / kg, and 150.02 mg / kg, respectively, which were 26.66 times, 13.42 times, and 4.73 times higher than those in the sodium selenate treatment at the same concentrations. Therefore, sodium selenite is more conducive to the absorption and accumulation of Se in the roots, stems, and leaves of *Aster tataricus* than sodium selenate.

[0102] With increasing Se concentration, the inorganic and organic Se contents in the roots, stems, and leaves of *Aster tataricus* treated with sodium selenite all showed an increasing trend, with significant differences among treatments (P<0.05). The inorganic and organic Se contents in the roots of *Aster tataricus* treated with sodium selenite showed a trend of first increasing and then decreasing, while the inorganic and organic Se contents in the stems showed a trend of first decreasing and then increasing. However, the inorganic and organic Se contents in the leaves showed a gradual increasing trend, with significant differences among treatments (P<0.05). In all cases of exogenous Se addition, the Se content in the roots, stems, and leaves of *Aster tataricus* showed that organic Se > inorganic Se, indicating that *Aster tataricus* can convert inorganic Se into organic Se during Se absorption. Furthermore, the inorganic and organic Se contents in the roots, stems, and leaves of *Aster tataricus* were analyzed using sodium selenite and sodium selenate at the same concentrations. The results showed that, except for the 10 mg / L treatment, the inorganic and organic Se contents in the roots, stems, and leaves of *Aster tataricus* treated with sodium selenite were significantly higher than those treated with sodium selenate. At a concentration of 40 mg / L, the sodium selenite treatment resulted in the highest inorganic and organic Se contents in the roots, stems, and leaves. The inorganic Se contents were 159.67 mg / kg, 34.37 mg / kg, and 31.96 mg / kg, respectively, which were 23.76 times, 12.54 times, and 4.28 times higher than those in the sodium selenate treatment at the same concentration. The organic Se contents were 452.66 mg / kg, 83.03 mg / kg, and 124.06 mg / kg, respectively, which were 27.86 times, 13.82 times, and 5.10 times higher than those in the sodium selenate treatment at the same concentration. Therefore, compared to sodium selenite, sodium selenite is more beneficial for the absorption of Se and the accumulation and conversion of organic Se in the roots, stems, and leaves of *Aster tataricus* when used as a Se source. Comparative analysis revealed that when the sodium selenite concentration was 10 mg / L, the proportion of selenium concentrated in the above-ground parts and stems and leaves was higher. Therefore, this invention preferably uses 10 mg / L sodium selenite for cultivation, significantly improving the edible value of *Aster tataricus*.

[0103] Experiment 2: Selenium enrichment experiment in the roots of *Aster tataricus*

[0104] 1. Experimental Methods:

[0105] Based on the above experiments, further research was conducted using the selenium-containing nutrient solution of Example 2 containing 10 mg / L sodium selenite. Specifically, Aster tataricus seedlings (Aster tataricus seedlings were obtained by planting Aster tataricus seeds in Se-free soil after ethanol disinfection) were cultured in a glass greenhouse using the selenium-free nutrient solution of Example 2. Seedlings with uniform growth and 6 complete leaves were selected, their roots were rinsed with ultrapure water, and they were transplanted into plastic buckets with a mouth diameter, height and bottom diameter of 16 cm, a height of 11 cm and a bottom diameter of 9 cm, respectively. Each bucket contained 1.0 kg of sand, and 3 Aster tataricus seedlings were planted in each bucket. 0.5 L of the selenium-free nutrient solution of Example 2 was applied, and 0.5 L of the selenium-free nutrient solution of Example 2 was applied every 2 days to maintain the growth of Aster tataricus. After 15 days of cultivation, 0.5 L of the complete nutrient solution from Example 2 was added, and the same amount of the complete nutrient solution from Example 2 was added every 14 days thereafter. Before use, the pH of both nutrient solutions was adjusted to approximately 5.6 with 0.1 mol / L NaOH or 0.1 mol / L HCl. After the initial application of the selenium-containing nutrient solution, different selenium absorption promoters were sprayed every 10 days, with each treatment repeated 3 times. The experimental design for different selenium absorption promoters was as follows: CK control, zeatin 0.5 mg / L, zeatin 5 mg / L, zeatin 10 mg / L, abscisic acid (ABA) 0.2 mg / L, abscisic acid (ABA) 0.5 mg / L, abscisic acid (ABA) 1.0 mg / L, spermidine 20 mg / L, spermidine 50 mg / L, spermidine 100 mg / L, indoleacetic acid (IAA) 0.2 mg / L, indoleacetic acid (IAA) 0.5 mg / L, and indoleacetic acid (IAA) 1.0 mg / L. During the cultivation period, ultrapure water was added intermittently to keep the quartz sand moist and maintain the growth of Aster tataricus. After 60 days, the plant height and total fresh weight of Aster tataricus in each treatment were measured and the plants were harvested for later use.

[0106] 2. Sample preparation and analysis methods

[0107] Sample processing is the same as the sample preparation and analysis method described in 1.2 above.

[0108] The detection methods are as follows: The plant height and total fresh weight of *Aster tataricus* were determined by direct measurement, and the total dry weight of the roots, stems, and leaves was determined by the drying constant weight method. The results are shown in Table 4. The total selenium content of each part of the roots, stems, and leaves of *Aster tataricus* was determined by GB / T 5009.93 "Determination of Selenium in Food (Method I: Hydride Atomic Fluorescence Spectrometry)". The results are shown in Table 5.

[0109] 3. Experimental Results and Analysis:

[0110] Table 4

[0111]

[0112]

[0113]

[0114]

[0115] Table 5

[0116]

[0117]

[0118]

[0119]

[0120] Note: In Tables 4 and 5, three plants were selected for each replicate for testing.

[0121] Table 4 shows that the addition of different concentrations of zeatin, abscisic acid, and spermidine significantly increased the plant height, total fresh weight, and total dry weight of *Aster tataricus* compared to the control group. However, the addition of different concentrations of indoleacetic acid did not result in significant differences in plant height, total fresh weight, and total dry weight compared to the control group. This indicates that the addition of zeatin, abscisic acid, and spermidine promotes the growth of *Aster tataricus*. Table 5 shows that the selenium-rich parts of *Aster tataricus* are mainly in the roots. The root selenium content in the control group (CK) was 336.09 mg / kg, while the root selenium content of *Aster tataricus* sprayed with 0.5 mg / L zeatin reached 476.84 mg / kg, those sprayed with 0.5 mg / L abscisic acid reached 391.86 mg / kg, those sprayed with 1.0 mg / L abscisic acid reached 402.68 mg / kg, and those sprayed with 50 mg / L spermidine reached 468.19 mg / kg—all significantly higher than the CK group. However, the root selenium content of *Aster tataricus* sprayed with indoleacetic acid did not differ significantly from the CK group. This indicates that appropriate amounts of zeatin, abscisic acid, and spermidine can promote selenium absorption in the roots of *Aster tataricus*, improve its growth, and yield higher quality selenium-enriched *Aster tataricus*.

[0122] It should be noted that although the experiment in this invention uses sand culture + nutrient solution for experimental research, in actual cultivation work, soil culture + selenium-containing fertilizer can also be used in combination with the application of zeatin, abscisic acid and spermidine to cultivate selenium-enriched Aster tataricus.

[0123] The above description is a detailed description of the preferred embodiments of the present invention. However, the embodiments are not intended to limit the scope of the patent application of the present invention. All equivalent changes or modifications made under the technical spirit of the present invention should fall within the patent scope covered by the present invention.

Claims

1. A method for cultivating high-selenium-enriched Aster tataricus, characterized in that, The process includes the following steps: cultivating *Aster tataricus* seedlings, applying selenium-containing nutrient solution or fertilizer after 15 days of cultivation, and then regularly supplementing with the selenium-containing nutrient solution or fertilizer until harvest; after the first application of the selenium-containing nutrient solution or fertilizer, spraying a selenium absorption promoter every 7-10 days until harvest; the selenium absorption promoter is 0.5 mg / L zeatin or 0.5 mg / L~1.0 mg / L abscisic acid or 50 mg / L spermidine; The selenium-containing nutrient solution is composed of the following components: KNO3 2.0~4.0 mmol / L; Ca(N03)2·4H2O 0.5~1 mmol / L; MgSO4·7H2O 0.2~0.5mmol / L; KH2PO4 0.01~0.1 mmol / L; H3BO3 10~12 µmol / L; MnCl2·4H2O 2.0~5 µmol / L; ZnSO4·7H2O 0.3~0.5 µmol / L; CuSO4.5H2O 0.20 ~0.40µmmol / L; (NH4)2MoO4 0.1~0.2 µmmol / L; Fe-EDTA 20~40µmmol / L; Selenium element: Sodium selenite 10mg / L.

2. The method for cultivating high-selenium-enriched Aster tataricus according to claim 1, characterized in that, Before use, the pH of the selenium-containing nutrient solution needs to be adjusted to 5.5-6.0 with 0.1 mol / L NaOH or 0.1 mol / L HCl.

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