Method for cultivating mulberry leaves indoors and application of method in improving secondary metabolites of mulberry leaves

Abstract

The invention relates to an indoor medicine mulberry cultivation method and application of the indoor medicine mulberry cultivation method to improvement of secondary metabolites of indoor medicine mulberries, and the indoor medicine mulberry cultivation method comprises the steps of transplanting, illumination, fertilization and management.The inorganic fertilizer is applied in the growth period of the medicine mulberries, so that the secondary metabolites of the indoor medicine mulberries are effectively improved; particularly, the high-potassium fertilizer has the most obvious effect of improving the active substances of the indoor medicinal mulberry, and can improve the content of flavone and flavonol substances in the medicinal mulberry by influencing the bioanabolic pathway of flavone and flavonol at the same time.

Description

Technical Field

[0001] The invention belongs to the technical field of mulberry planting, and relates to indoor cultivation of medicinal mulberry, and specifically to a method for indoor cultivation of medicinal mulberry and an application of the method in improving secondary metabolites of the medicinal mulberry. Background Art

[0002] Mulberry trees are first known as the main food source for silkworms, but they also play a vital role in ecological restoration. Mulberry trees are a treasure, and mulberry leaves, mulberry bark, mulberry, mulberry branches, etc. all have certain medicinal functions. Medicinal mulberry contains a variety of nutrients such as flavonoids, polysaccharides, polyphenols, alkaloids, minerals, vitamins, etc., and has the functions of lowering blood sugar, lowering blood lipids, anti-oxidation, anti-inflammatory analgesia, and delaying aging. The chromosome ploidy of medicinal mulberry is 22 ploid (22n=308), which is unique among all mulberry germplasm resources. Therefore, it also gives medicinal mulberry great research value and economic value. At the same time, studies have shown that among various mulberry resources, the content of DNJ ((1-deoxynojirimycin), N-methyl-1-DNJ (N-Me-DNJ), 2-oxy-α-D-galactopyranoside-1-DNJ, fagomine, and other alkaloids) in medicinal mulberry is the highest, among which the content of rutin is 0.85-1.14 mg / g, the content of isoquercetin is 0.66-0.85 mg / g, and the content of astragaloside is 0.09-0.29 mg / g. Flavonoids and flavonols have a wide range of biological activities, including antioxidant and free radical scavenging activities, can inhibit the growth of cancer cells, induce apoptosis, have anti-tumor effects, reduce cholesterol synthesis, lower serum cholesterol concentrations, prevent atherosclerosis, have cardiovascular protection, and also have metabolic regulation and anti-fatty liver effects.

[0003] In summary, medicinal mulberry has a very high development value of "medicine and food". However, after the medicinal mulberry was transplanted to Sichuan and Chongqing, the growth trend of the medicinal mulberry did not reach the expected state. Grafted medicinal mulberry is difficult to develop and grow continuously. Even if tissue culture can enable the medicinal mulberry to survive and grow, its biomass cannot meet the needs of production. Therefore, the cultivation conditions of medicinal mulberry need further exploration. There are many factors that affect the growth of medicinal mulberry, including temperature, humidity, light, fertilizer, etc. Commonly used medicinal mulberry cultivation fertilizers include organic fertilizers and inorganic fertilizers, and inorganic fertilizers are high-nitrogen inorganic fertilizers. Summary of the invention

[0004] Based on this, the purpose of the present invention is to provide a method for indoor cultivation of medicinal mulberry, which can not only make the medicinal mulberry develop and grow, but also can well increase the secondary metabolites of the cultivated medicinal mulberry, especially increase the content of active substances such as flavonoids and flavonols.

[0005] The technical solution for achieving the above-mentioned purpose is as follows.

[0006] The first aspect of the present invention is to provide a method for indoor cultivation of medicinal mulberry, the method comprising the following steps:

[0007] After the tissue culture seedlings of the medicinal mulberry are rooted, they are transplanted into an artificially illuminated greenhouse for growth and fertilized. The fertilization is performed by applying inorganic fertilizers containing nitrogen, phosphorus and potassium during the vigorous growth period of the medicinal mulberry, wherein the mass ratio of nitrogen, phosphorus and potassium is (10-16): (4-10): (36-45).

[0008] In some of the embodiments, the mass ratio of nitrogen, phosphorus and potassium is (12-14): (6-8): (38-42).

[0009] The mass ratio of the above-mentioned nitrogen, phosphorus and potassium is preferably 13:7:(39-41).

[0010] In some of the embodiments, the volume ratio of the matrix used for transplanting is soil: perlite: vermiculite = (3-5): (0.8-1.2): (1.8-2.2).

[0011] Furthermore, the volume ratio of the matrix used for transplanting is soil: perlite: vermiculite = 4:1:2.

[0012] In some embodiments, the mass ratio of the inorganic fertilizer to the transplanting medium is 1:900-1100, preferably 950-1050.

[0013] In some embodiments, inorganic fertilizer is dissolved in water and applied once every 15 days.

[0014] In some embodiments, in the aforementioned method of indoor cultivation of medicinal mulberry, the lighting conditions of the artificial lighting are 25° C., (30-50)% RH, and 15-17 hours of light per day.

[0015] Furthermore, the lighting conditions of the artificial lighting are 25° C., 40% RH, the light source is an LED light source with a PPF of 171 μmol / s, the daily lighting hours are 16 hours, and the daily lighting time is from 7:30 to 23:30.

[0016] The second aspect of the present invention is to provide an application of the aforementioned method for indoor cultivation of medicinal mulberry in increasing the secondary metabolites of indoor cultivation of medicinal mulberry.

[0017] The present invention finds that when medicinal mulberry is cultivated indoors, applying fertilizer can effectively promote the growth of medicinal mulberry. However, research finds that the growth of medicinal mulberry is not positively correlated with the amount of secondary metabolites of the medicinal mulberry. It is further found that when nitrogen, phosphorus and potassium fertilizers with suitable ingredients are used, especially high-potassium fertilizers, the secondary metabolites of the medicinal mulberry cultivated indoors can be effectively increased, and the increase in the active substances of flavonoids of the indoor medicinal mulberry is most obvious. The content of flavonoids and flavonols in the medicinal mulberry can be increased by affecting the biosynthetic metabolic pathways of flavonoids and flavonols. On this basis, the method for cultivating medicinal mulberry indoors provided by the present invention can make the medicinal mulberry cultivated indoors grow well through high-potassium fertilizers, and can also increase the secondary metabolites of the medicinal mulberry, especially the content of flavonoids, thereby improving the medicinal value of the medicinal mulberry. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 This is the OPLS-DA analysis under different fertilization treatments. A: control group, B: high nitrogen fertilizer group, C: high potassium fertilizer group, D: high phosphorus fertilizer group, E: organic fertilizer group, F: biological fertilizer group.

[0019] Figure 2 The effect of different fertilizer treatments on the biomass and morphology of indoor medicinal mulberry. A leaf fresh weight, B leaf dry weight, C leaf number, C branch fresh weight, E branch dry weight, F plant height. Different lowercase letters marked on the bar graph indicate significant differences (n=8, p<0.05) obtained by analysis of variance and multiple range test. Control group (CK), high nitrogen treatment group (HN), high potassium treatment group (HK), high phosphorus treatment group (HP), organic fertilizer treatment group (OF) and biological fertilizer treatment group (BF).

[0020] Figure 3 The effect of different fertilizer treatments on chlorophyll fluorescence (ChlF) and relative chlorophyll content (SPAD) of indoor medicinal mulberry. a: Maximum photochemical efficiency of photosystem II (FV / FM). b: Y(Ⅱ): Actual light energy conversion efficiency of leaves under light. c: ETR: Leaf electron transfer efficiency. d: qP: Photochemical quenching coefficient. e: qL: Photochemical quenching coefficient. f: Y(NO): Non-photochemical quenching factor. g: Y(NPQ): An important indicator of light damage. h: qN: Non-photochemical quenching factor. i: Soil and Plant Analysis Development (SPAD) chlorophyll meter value: Relative chlorophyll content. Different lowercase letters marked on the bar graph indicate significant differences obtained by analysis of variance and multiple range test (n=8, p<0.05).

[0021] Figure 4The figure shows the changes of mulberry leaf metabolites under different fertilizer treatments. The color of the material is used to visualize the content of the material. Red and green respectively indicate the increase or decrease of the corresponding parameters. Among them, CK: control group, HN: high nitrogen fertilizer group, HK: high potassium fertilizer group, HP: high phosphorus fertilizer group, OF: organic fertilizer group, BF: biological fertilizer group.

[0022] Figure 5 These are the differential anabolic metabolites of mulberry leaves under different fertilization treatments, including A: CK vs HN, B: CK vs HK, C: CK vs HP, D: CK vs OF, E: CK vs BF; metabolites with VIP>1, Log2FC≥1 or ≤-1, and p<0.05 were identified as differential anabolic metabolites.

[0023] Figure 6 Figure 2 is the KEGG enrichment analysis of differentially synthesized metabolites, where A: CK vs HN, B: CK vs HK, C: CK vs HP, D: CK vs OF, E: CK vs BF; the size and color of the dots represent the number and significance (p-value) of metabolites, respectively. DETAILED DESCRIPTION

[0024] In order to facilitate the understanding of the present invention, the present invention will be described more fully below. The present invention can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the understanding of the disclosure of the present invention more thorough and comprehensive.

[0025] The experimental methods in the following examples without specifying specific conditions are usually carried out under conventional conditions or conditions recommended by the manufacturers. The various commonly used chemical reagents used in the examples are all commercially available products.

[0026] Unless otherwise defined, all technical and scientific terms used in the present invention have the same meaning as those commonly understood by those skilled in the art to which the present invention belongs. The terms used in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "and / or" used in the present invention includes any and all combinations of one or more of the related listed items.

[0027] In addition, as used in the present invention, the term "or" is an inclusive "or" symbol and is equivalent to the term "and / or", unless the context clearly dictates otherwise. The term "based on" is not exclusive and allows for being based on other factors not described, unless the context clearly dictates otherwise. In addition, throughout the specification, the meanings of "a", "an", and "the" include plural referents. The meaning of "in..." includes "in..." and "on...".

[0028] The present invention is further described in detail below with reference to specific embodiments.

[0029] Example 1

[0030] 1. Plant materials, growth and fertilizer sources

[0031] In January 2024, the medicinal mulberry was transplanted from tissue culture seedlings to 30 cm × 28 cm pots with a substrate ratio of soil: perlite: vermiculite = 4:1:2. Each pot was loaded with 2.5 kg of substrate and grown in an artificially lit greenhouse (25 ° C, 40% RH). The growth light source was a 171 μmol / s PPF LED light source (ZK3-TB14-VE03 / A, SANANBIO, China), and the daily lighting time was 7:30 to 23:30. Fertilization was stopped for one month in May 2024, and the branches were cut off in June 2024, retaining 2 buds on each branch. Fertilization treatment was then started for 45 consecutive days.

[0032] The inorganic fertilizers were commercial fertilizers purchased from the Sino-Agri Fertilizer flagship store, where the ratio of NPK in high-nitrogen fertilizers was 30:10:10 and a small amount of trace elements, the ratio of NPK in high-potassium fertilizers was 13:7:40 and a small amount of trace elements, and the ratio of NPK in high-phosphorus fertilizers was 10:48:10 and a small amount of trace elements.

[0033] Organic fertilizer: made from composted and fermented chicken manure, sheep manure and cow manure, with a volume ratio of 1:1:1.

[0034] The biofertilizer was purchased from Henan Nanhua Qianmu Co., Ltd. and was made of Bacillus subtilis with an effective live bacteria count of ≥20 billion / g.

[0035] 2. Treatment method

[0036] Control group: only watering without fertilizer.

[0037] Inorganic fertilizer group: Dissolve the inorganic fertilizer in water at a concentration of 10g / L, and irrigate each pot with 250ml of inorganic fertilizer solution once every 15 days.

[0038] Organic fertilizer group: 250g / pot, 15d / time.

[0039] Biofertilizer group: Dissolve the biofertilizer in water at a concentration of 10 g / L and irrigate each pot with 250 ml of inorganic fertilizer solution once every 15 days.

[0040] There were 8 replicates in each treatment group.

[0041] 3. Metabolic analysis

[0042] 45 days after the fertilization treatment, the third fully expanded leaf at the top of the morphological mulberry branch was selected, quickly immersed in liquid nitrogen after measurement, and then stored in a -80°C refrigerator. The mulberry leaves were freeze-dried for 96 hours using a vacuum freeze dryer (ScanSpeed ​​MaxiVac Beta, LaboGene, America), and after drying, they were processed with a ball mill (MM400, Retsch GmbH, Haan, Germany) at a frequency of 30 Hz for 5 minutes to fully crush the dried mulberry samples.

[0043] During extraction, 100 mg of dried medicinal mulberry sample powder was accurately weighed into a 1.5 mL centrifuge tube, dissolved in 1.25 mL of 70% methanol aqueous solution, vortexed for 30 s for 3 times, each time with an interval of 10 min, and then stored at 4 ° C overnight. The sample was then centrifuged at 12000 rpm for 10 min, and the supernatant was filtered through a 0.22 μm nylon filter membrane into a sample injection glass bottle for UPLC-MS / MS analysis.

[0044] 4. Data Analysis

[0045] UPLC-MS / MS data were quantitatively calculated using Thermo Scientific Xcalibur v2.2. Metabolomics analysis was performed using the Metware platform (https: / / cloud.metware.cn).

[0046] 5. Results:

[0047] 5.1. OPLS-DA model is stable and reliable

[0048] The control group and each experimental group were subjected to OPLS-DA analysis. The results are shown in Figure 1 The sample points of each experimental group are clearly separated and in different intervals, indicating that there are significant differences between different treatment groups (left figure). The R 2 Y is close to 1, and Q 2 A value greater than 0.5 indicates that the model is stable and reliable (right figure).

[0049] 5.2 Growth Analysis

[0050] Fertilization can significantly promote the biomass accumulation of mulberry plants ( Figure 2 ). The biological fertilizer (BF) treatment showed the most significant effect, increasing the leaf fresh weight to 414.73% of the control group (CK), the dry weight to 379.55%, and the number of leaves to 204.88% (p<0.05), which was significantly better than the inorganic fertilizer treatment group (IF) and the organic fertilizer treatment group (OF) ( Figure 2ac). Although inorganic fertilizer (IF) and organic fertilizer (OF) treatments with different N, P, and K ratios only resulted in limited increases in leaf fresh weight (leaf fresh weight: 186.4%-236.26%, dry weight: 181.11%-227.23%), the increase brought about by the biofertilizer (BF) treatment was 2.2-2.7 times higher than the maximum increase of inorganic fertilizer (IF) and organic fertilizer (OF). The response of stem biomass showed a treatment-specific pattern: high potassium treatment (HK) increased stem fresh weight to 229.12% and dry weight to 218.84%. High phosphorus treatment (HP) increased these parameters to 216.28% and 210.16%, respectively. The biofertilizer (BF) treatment showed a superior effect (fresh weight: 372.99%; dry weight: 371.80%). High nitrogen treatment (HN) and organic fertilizer (OF) treatments failed to achieve statistically significant increases in stem biomass. Further measurements of plant height confirmed these trends: plant heights under high potassium treatment (HK) and biofertilizer treatment (BF) reached 177.76% and 228.80% of the control group's plant height, respectively, reflecting that biofertilizer (BF) has a synergistic effect on the development of both source organs (leaves) and sink organs (stems).

[0051] After 45 days of fertilizer treatment on indoor medicinal mulberry, the chlorophyll fluorescence kinetics and SPAD values ​​were measured comprehensively ( Figure 3 ai). Compared with the control group (CK), fertilization significantly regulated the photosynthetic parameters. Positive regulation was manifested as: the maximum photochemical efficiency of photosystem II (FV / FM) increased to 177.06% to 187.77% (inorganic fertilizer treatment group, IF), 161.78% (organic fertilizer treatment group, OF), and 175.65% (biological fertilizer treatment group, BF). The actual photochemical efficiency of photosystem II (Y(II)) increased to 357.55% to 468.33% (inorganic fertilizer group), 428.58% (organic fertilizer group), and 484.22% (biological fertilizer group). The electron transfer rate (ETR) increased to 136.68% to 170.5% (inorganic fertilizer group), 155.98% (organic fertilizer group), and 176.18% (biological fertilizer group). The photochemical quenching coefficient (qP) increased to 242.90% to 300.10% (inorganic fertilizer group), 327.82% (organic fertilizer group), and 321.03% (biofertilizer group). The non-photochemical quenching coefficient (qL) increased to 280.8% to 395.97% (inorganic fertilizer group), 492.95% (organic fertilizer group), and 443.32% (biofertilizer group). The relative chlorophyll content (SPAD) increased to 124.04% to 143.6% (inorganic fertilizer group), 139.62% (organic fertilizer group), and 150.62% (biofertilizer group) ( Figure 3 ae, i).

[0052] The specific treatment effects showed that the relative chlorophyll content (SPAD) of the biofertilizer treatment group was the highest (150.62% of the control group, Figure 3 i), which is associated with leaf biomass advantage ( Figure 2 ac). The organic fertilizer treatment group (OF) made the photochemical quenching coefficient (qP, 327.82% of the control group) and the non-photochemical quenching coefficient (qL, 492.95% of the control group) reach the maximum value ( Figure 3 de). The high nitrogen treatment group had the least effect in improving photosynthetic performance and alleviating stress.

[0053] All fertilizer treatments reduced the photoinhibition indices: Y(NO), Y(NPQ), qN: significantly inhibited by the high potassium treatment group (p<0.05, the decrease was 8.07% to 35.35%), and significantly inhibited by the biofertilizer treatment (p<0.05, the decrease was 8.64% to 39.75%) ( Figure 3 fh).

[0054] Key analytical features: Parameter correlation: Parallel trends (r>0.95) between Y(II) and ETR confirmed the validity and functional consistency of the measurements; The dual efficacy of the biofertilizer treatment (BF) in terms of relative chlorophyll content (SPAD, source intensity) and fluorescence index (photosynthetic efficiency) reflected its Figure 2 Stress threshold: The unfertilized control group showed chronic light inhibition (basic Y(NO)>0.35), and the high potassium treatment group and the biological fertilizer treatment group had the most significant improvement effect.

[0055] 5.3 Differences in metabolic substances of indoor medicinal mulberry under different fertilization treatments

[0056] Based on UPLC-MS / MS and a self-built database, a total of 82 metabolites were detected, including 13 alkaloids, 12 amino acids, 2 fatty acids, 18 flavonoids, 7 lysophospholipids, 4 nucleic acids and nucleic acid derivatives, and C 19 H 39 N 2 O 3 + 1, phenolic acid 1, peptides 5, tryptophan metabolites 1, vitamins 8 and other 10 substances. The contents of these substances are displayed in the form of a heat map. Figure 4 As shown, from Figure 4It can be seen that the application of fertilizers can increase or decrease the regulation of some active substances in medicinal mulberry. Cluster analysis clusters the high nitrogen fertilizer group, high potassium fertilizer group, and high phosphorus fertilizer group together, indicating that the application of chemical fertilizers has a more obvious effect on active substances than organic fertilizers, biological fertilizers, and the control group. Among chemical fertilizers, the application of high potassium fertilizers can increase most of the active substances in indoor medicinal mulberry, which is significantly better than other chemical fertilizer groups. The results show that for the improvement effect of indoor medicinal mulberry active substances, high potassium fertilizer> high nitrogen fertilizer> high phosphorus fertilizer> biological fertilizer=organic fertilizer> control group.

[0057] The metabolites in the indoor medicinal mulberry under different fertilization treatments were compared with those in the control group, and the differentially synthesized metabolites with VIP>1, |log2FC|>1 and p<0.05 were screened out. Figure 5 As shown in the figure, compared with the control group, 11 metabolites were upregulated in the high nitrogen fertilizer group, mainly flavonoids, and 1 substance was downregulated, mainly tyrosine ( Figure 5 A). Compared with the control group, 21 metabolites were upregulated in the high potassium fertilizer group, mainly flavonoids ( Figure 5 B). Compared with the control group, 4 metabolites were up-regulated in the high-phosphate fertilizer group, mainly flavonoids, and 1 metabolite was down-regulated, namely niacin ( Figure 5 C). Compared with the control group, the use of organic fertilizer increased the levels of two metabolites in the medicinal mulberry, namely L-pipecolic acid and L-carnitine. One substance decreased, namely L-aspartic acid ( Figure 5 D). Compared with the control group, the use of biofertilizer can increase the expression of two substances in medicinal mulberry, namely, fargomin O-hexoside-I and L-aspartic acid, and decrease the expression of one substance, namely, salicylic acid derivatives ( Figure 5 E).

[0058] 5.4 KEGG pathway enrichment analysis of differential metabolites of indoor medicinal mulberry under different fertilization treatments

[0059] The differential metabolites were subjected to KEGG pathway enrichment analysis, focusing on metabolic pathways with p < 0.05. The differential metabolites of the CK vs HN group were annotated to 38 pathways, but there was no significantly enriched pathway ( Figure 6 A). In the CK vs HP group, the biosynthetic metabolic pathway of flavonoids and flavonols (ko00944) was significantly enriched ( Figure 6 B). Kaempferol 3-o-glucoside; luteolin 7-o-glucoside; quercetin 3-o-glucoside: quercetin 3-O-malonyl glucoside: rutin. These five substances are involved in this metabolic pathway and all show an upward trend ( Figure 5 B). The metabolic pathways of niacin and nicotinamide (ko00760) were significantly enriched in the CK vs HP group ( Figure 6 C). Niacin and L-aspartic acid are involved in this metabolic pathway, and the content of niacin is downregulated ( Figure 5 C). There were two metabolic pathways significantly enriched in the CK vs OF group, namely the biosynthesis of ornithine, lysine and nicotinic acid-derived alkaloids (ko01064) and microbial metabolism under different environments (ko01120) ( Figure 6 D). L-piperidinic acid and aspartic acid were involved in this metabolic pathway, with aspartic acid showing a downward trend and L-piperidinic acid showing an upward trend ( Figure 5 D). A total of 34 metabolic pathways were designed for the differential metabolites in the CK vs BF group, but there was no significantly enriched metabolic pathway ( Figure 6 E).

[0060] 5.5. The results show that only 8 flavonoids and flavonols were upregulated in the high nitrogen fertilizer group, among which rutin increased by 2.2 times, astragaloside increased by 9.5 times, quercetin 3-O-glucoside increased by 2.3 times, and kaempferol increased by 3 times compared with the control group.

[0061] In the high-potassium fertilizer group, 15 flavonoids and flavonols were upregulated, including rutin increased by 4.8 times, astragalus glycoside increased by 30 times, quercetin 3-O-glucoside increased by 5.9 times, and kaempferol increased by 7 times compared with the control group.

[0062] In summary, the application of fertilizers can effectively promote the growth of medicinal mulberry, especially the biological fertilizer group has the most significant promoting effect on medicinal mulberry. However, further studies found that the biological fertilizer group could not significantly increase the content of active substances in medicinal mulberry. On the contrary, although the growth-promoting effect of the inorganic fertilizer group was not as good as that of the biological fertilizer group, the application of inorganic fertilizer could increase the content of active substances in indoor medicinal mulberry, mainly concentrated in flavonoids. In particular, high-potassium fertilizer had the most obvious effect on the improvement of active substances in indoor medicinal mulberry. At the same time, it could affect the biosynthetic metabolic pathways of flavonoids and flavonols, thereby increasing the content of flavonoids and flavonols in medicinal mulberry.

[0063] The above-mentioned embodiments only express several implementation methods of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. A method for indoor cultivation of medicinal mulberry, characterized in that: After the tissue culture seedlings of the medicinal mulberry are rooted, they are transplanted into an artificially illuminated greenhouse for growth and fertilized. The fertilization is performed by applying inorganic fertilizers containing nitrogen, phosphorus and potassium during the vigorous growth period of the medicinal mulberry, wherein the mass ratio of nitrogen, phosphorus and potassium is (10-16): (4-10): (36-45).

2. The method for indoor cultivation of medicinal mulberry as claimed in claim 1, characterized in that: The mass ratio of nitrogen, phosphorus and potassium is (12-14): (6-8): (38-42).

3. The method for indoor cultivation of medicinal mulberry as claimed in claim 2, characterized in that: The mass ratio of nitrogen, phosphorus and potassium is 13:7:(39-41).

4. The method for indoor cultivation of medicinal mulberry as claimed in claim 1, characterized in that: The volume ratio of the matrix used for transplanting is soil: perlite: vermiculite = (3-5): (0.8-1.2): (1.8-2.2).

5. The method for indoor cultivation of medicinal mulberry trees as claimed in claim 4, characterized in that: The volume ratio of the matrix used for transplanting is soil: perlite: vermiculite = 4:1:

2.

6. The method for indoor cultivation of medicinal mulberry trees as claimed in any one of claims 1 to 5, characterized in that: The mass ratio of the inorganic fertilizer to the transplanting substrate is 1:900-1100, preferably 1:950-1050.

7. The method for indoor cultivation of medicinal mulberry trees according to any one of claims 1 to 5, characterized in that: Dissolve inorganic fertilizer in water and apply fertilizer every 15 days.

8. The method for indoor cultivation of medicinal mulberry trees as claimed in any one of claims 1 to 5, characterized in that: The lighting conditions of the artificial lighting are 25° C., (30-50)% RH, and 15-17 hours of lighting per day.

9. The method for indoor cultivation of medicinal mulberry trees as claimed in claim 8, characterized in that: The lighting conditions of the artificial lighting are 25° C., 40% RH, the light source is an LED light source with a PPF of 171 μmol / s, the lighting hours are 16 hours per day, and the lighting time is from 7:30 to 23:

30.

10. Use of the method according to any one of claims 1 to 9 in increasing the secondary metabolites of indoor cultivated medicinal mulberry.

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