Nutrient solution for cultivating cynara plantago-aquatica and cultivating method of cynara plantago-aquatica

Abstract

The invention discloses a nutrient solution for cultivating cynara plantago, and belongs to the technical field of plant cultivation, the nutrient solution comprises a Hoagland nutrient solution, auxin and a plant growth retardant, the concentration of the auxin is 0-0.01 mg / L, and the concentration of the plant growth retardant is 0.005-0.01 mg / L. According to the method, the problem that the survival rate of the plantain thistle seedlings is low is solved, the overall growth of the plantain thistle seedlings is effectively promoted, the plantain thistle seedlings with developed root systems and robust plant types are efficiently cultivated, and therefore the survival rate of transplanting is remarkably increased. The invention further provides a seedling raising method for cultivating the cynara plantaginis.

Description

Technical Field

[0001] This invention relates to the field of plant culture technology, and in particular to a nutrient solution and cultivation method for cultivating Plantago asiatica. Background Technology

[0002] *Ageratum plantain* is a species belonging to the Boraginaceae family and the *Ageratum* genus within the eudicotyledonous plant clade. Its seed oil is rich in omega-3 long-chain polyunsaturated fatty acids, including n-3 polyunsaturated fatty acids and high levels of the rare fatty acids glycyrrhizic acid and octadecanoic acid. These fatty acids have been shown to help reduce the risk of cardiovascular disease, regulate inflammation and immune responses, improve infant brain development and vision, improve age-related degenerative diseases, and regulate depression and mood disorders, thus possessing significant health and medicinal value. For large-scale and standardized cultivation, seedling cultivation is a crucial step in obtaining *Ageratum plantain*.

[0003] Currently, Hoagland nutrient solution formulations are the most widely used in plant seedling research and agriculture. With continuous in-depth research and development of plant nutrient solutions, their composition is constantly changing. However, when using Hoagland nutrient solution for seedling cultivation of crops such as blue thistle, tomato, and watermelon, it has been found that while existing nutrient solutions can promote rapid early growth of blue thistle seedlings, they easily lead to tall, weak seedlings, and the survival rate is very low when transplanted to the field, affecting seedling vigor and significantly reducing the survival rate.

[0004] Therefore, providing a nutrient solution formula that can effectively promote the growth of plantlets, leaves, and stems of *Ageratum truncata*, as well as the coordinated and balanced growth of the plantlets, to achieve efficient and robust *Ageratum truncata* seedling cultivation, is an urgent problem to be solved. Summary of the Invention

[0005] In order to overcome the shortcomings of the existing technology, the purpose of this invention is to solve the problem of low survival rate of Plantago asiatica seedlings, effectively promote the overall growth of Plantago asiatica seedlings, and efficiently cultivate Plantago asiatica seedlings with well-developed root systems and robust plant types, thereby significantly improving the survival rate of transplanting.

[0006] To achieve the above objectives, the present invention provides a nutrient solution for cultivating Plantago asiatica, comprising Hoagland nutrient solution, auxin, and plant growth retardant, wherein the concentration of the auxin is 0–0.01 mg / L and the concentration of the plant growth retardant is 0.005–0.01 mg / L.

[0007] Preferably, the concentration of the auxin is 0.005 mg / L.

[0008] Preferably, the concentration of the plant growth retardant is 0.01 mg / L.

[0009] Preferably, the auxin includes either naphthaleneacetic acid or indolebutyric acid.

[0010] Preferably, the plant growth retardant includes one of chlormequat chloride, paclobutrazol, or chlormequat chloride.

[0011] To achieve the above objectives, the present invention also provides a method for cultivating *Ageratum plantainum* seedlings, comprising the following steps: taking *Ageratum plantainum* seedlings, periodically spraying the nutrient solution onto the *Ageratum plantainum* seedlings for cultivation, and obtaining cultivated *Ageratum plantainum* seedlings.

[0012] Preferably, the plantago seedlings are obtained by sterilizing plump plantago seeds and then cultivating them in a seedling substrate.

[0013] Preferably, the plantago seedlings have unfolded two cotyledons.

[0014] Preferably, the frequency of the regular spraying is once every 4 to 6 days.

[0015] Preferably, the nutrient solution is sprayed periodically onto the leaves and stem tips of the *Ageratum truncatum* seedlings.

[0016] Compared with the prior art, the beneficial effects of the present invention are as follows: By combining plant growth retardants with nutrient solutions, the synergistic effect of both effectively suppresses the common problem of excessive stem elongation in *Artemisia annua* seedlings, resulting in a nutrient solution formula for promoting strong roots and robust seedlings in *Artemisia annua*. This nutrient solution formula promotes vigorous growth of *Artemisia annua* seedlings, shortens the seedling time, and allows for rapid recovery after transplanting to the field, accelerating the seed harvest cycle. It is simple to operate, improves the survival rate, facilitates unified field management, and ultimately increases yield, making it easy to promote. Detailed Implementation

[0017] Where possible, the various embodiments described below can be rearranged to form other embodiments not shown in the following description; the various technical features described below can also be rearranged to form other embodiments not shown in the following description.

[0018] Example 1 To address the problem of excessive vegetative growth in *Ageratum truncatum* seedlings, this embodiment provides a nutrient solution for cultivating *Ageratum truncatum*, comprising Hoagland nutrient solution, auxin, and plant growth retardant. The concentration of the auxin is 0–0.01 mg / L, and the concentration of the plant growth retardant is 0.005–0.01 mg / L.

[0019]

[0020] Table 1. Reference Table for Hoagland Nutrient Solution Preparation The Hoagland nutrient solution in Table 1 provides comprehensive mineral nutrients to *Ageratum truncatum* seedlings, promoting rapid growth. However, it can lead to an imbalance in vegetative growth, such as excessive vertical cell growth and insufficient horizontal thickening, resulting in a "tall, weak seedling" phenomenon. Adding auxin alone can exacerbate excessive vegetative growth, leading to thin stems and leaves. While adding plant growth retardants alone can effectively inhibit excessive vegetative growth, thicken stems and leaves, thus solving the "tall, weak seedling" problem, it may result in excessive growth inhibition and insufficient leaf expansion, leading to decreased seedling vigor.

[0021] This application utilizes a combination of auxin and plant growth retardant to create a mutually restrictive yet mutually reinforcing system, resulting in more robust growth of *Ageratum plantain* seedlings. Auxin buffers the excessive inhibition of the plant growth retardant, preventing stunted growth, while the plant growth retardant corrects the tendency for thin stems and leaves caused by auxin, ensuring that *Ageratum plantain* seedlings maintain moderate growth vigor while possessing excellent stress resistance. High concentrations of both auxin and plant growth retardant may inhibit the growth of *Ageratum plantain* seedlings; therefore, controlling their concentrations within a low range ensures that the seedlings do not experience growth stagnation, deformities, or death due to nutrients during their most sensitive growth stages, thus guaranteeing a basic success rate in seedling cultivation.

[0022] In some embodiments, the concentration of auxin was 0.005 mg / L, and the concentration of plant growth retardant was 0.01 mg / L. By controlling the effects of different concentration gradients of auxin and mepiquat chloride on the seedling stage of *Artemisia plantain*, the optimal nutrient solution formula for promoting strong roots and robust seedlings of *Artemisia plantain* was determined. This combination of concentrations achieves an optimal balance of the synergistic effects of the two regulators, fully utilizing the seedling-strengthening function of the plant growth retardant while providing the necessary vitality and balance through auxin, thus obtaining the best-performing *Artemisia plantain* seedling cultivation.

[0023] In some embodiments, the auxin includes either naphthaleneacetic acid (NAA) or indolebutyric acid (IBA). NAA has a strong regulatory effect on stem and leaf growth and is significantly advantageous in controlling the morphology of aboveground stems and leaves, while IBA strongly promotes root development. The choice can be made based on the specific goals of the seedling stage. Both can produce effective synergistic effects with plant growth retardants within their respective concentration ranges, achieving the goal of cultivating robust seedlings. In addition to the types used in the specific embodiments, other auxin-like substances with similar functions of promoting cell elongation and division can also be selected.

[0024] In some embodiments, the plant growth retardant includes one of mepiquat chloride, paclobutrazol, or chlormequat chloride. Mepiquat chloride is a highly effective plant growth retardant that transfers growth advantage to the root system, fostering a well-developed root system and resulting in dwarfed, compact, and robust plants. Paclobutrazol has high activity and a strong and long-lasting dwarfing effect. Chlormequat chloride is less expensive and its effect on promoting stem thickening and leaf thickening is more noticeable. All three can achieve the goal of synergistically promoting robust seedlings with auxins. Because mepiquat chloride has a mild effect, it can produce a significant and stable effect of controlling excessive growth and promoting robust seedlings even at low concentrations. It also has high safety and is less likely to cause phytotoxicity or excessive inhibition, making it more suitable for the seedling stage of *Artemisia annua*. In addition to the types used in the specific embodiments, other substances with the function of inhibiting gibberellin synthesis and delaying internode elongation can also be selected as plant growth retardants.

[0025] Example 2 To achieve a high survival rate for robust *Ageratum plantain* seedlings transplanted into the field, this embodiment provides a method for cultivating *Ageratum plantainum* seedlings, including the following steps: *Ageratum plantainum* seedlings are taken, and the nutrient solution from Example 1 is periodically sprayed onto the seedlings for cultivation, resulting in cultivated *Ageratum plantainum* seedlings. *Ageratum plantainum* seedlings cultivated with the nutrient solution are more robust, which is beneficial for subsequent transplanting and growth. The spraying method allows the nutrient solution to directly act on the above-ground growing points, resulting in high absorption efficiency and facilitating large-scale application in greenhouse seedling production. Provided that the nutrient solution effectively acts on the upper part of the *Ageratum plantainum* seedlings, other application methods such as drip irrigation and misting can be explored in addition to spraying.

[0026] In some embodiments, *Artemisia plantain* seedlings are cultivated from plump *Artemisia plantain* seeds that have been sterilized and then placed in a seedling substrate. Plump *Artemisia plantain* seeds have ample nutrient reserves, and sterilization effectively removes pathogens carried on the seed surface, ensuring the health of the seedlings. The seedling substrate provides a consistent growth environment for the germination of *Artemisia plantain* seeds, resulting in seedlings that start in a uniform and healthy state, thus ensuring data reliability.

[0027] In some embodiments, the *Ageratum plantain* seedlings have already unfolded two cotyledons. The unfolding of the cotyledons allows the *Ageratum plantain* seedlings to shift from relying on their own stored nutrients to relying on external nutrients and photosynthesis, ensuring not only efficient utilization of the sprayed nutrient solution but also guaranteeing germination rate and seedling survival rate.

[0028] In some embodiments, the frequency of regular spraying is once every 4 to 6 days. Regular spraying can maintain a stable and effective regulatory signal in the plantlet *Ageratum spectabile*, continuously guiding it towards dwarfing, thicker stems, and thicker leaves, avoiding the intermittent etiolation problem that may be caused by single spraying. The spraying frequency can be adaptively adjusted according to the humidity, temperature, and other conditions of the seedling environment, for example, spraying once every 4, 5, or 6 days. Spraying every 5 days can better match the absorption and metabolism of nutrient solution by *Ageratum spectabile* seedlings and their rapid growth rhythm.

[0029] In some embodiments, the nutrient solution is periodically sprayed onto the leaves and stem tips of *Ageratum plantain* seedlings. The stem tip is the most active area for plant cell division and meristem, allowing the plant growth regulators in the nutrient solution to act directly on the key parts of *Ageratum plantain*, achieving rapid and efficient inhibition of excessive growth. This prevents auxins and plant growth regulators from being adsorbed and decomposed by the seedling substrate, ensuring efficient utilization by the *Ageratum plantain* seedlings.

[0030] The following section will provide a detailed explanation of the determination of Plantago asiatica leaves and Artemisia annua.

[0031] Test materials Select uniform, plump seeds of Plantago asiatica.

[0032] Experimental Design A randomized block design was used, with 10 treatment groups, including a control group and experiments 1–9. The control group was a water control; experiment 1 was Hoagland nutrient solution without auxin and mepiquat chloride; experiments 2–3 were Hoagland nutrient solutions with different concentrations of auxin; experiments 4 and 7 were Hoagland nutrient solutions with different concentrations of mepiquat chloride; and experiments 5–6 and 8–9 were Hoagland nutrient solutions with different combinations of auxin and mepiquat chloride.

[0033] Seedling raising methods Disinfect the seeds of *Ageratum plantain* with a 0.3% KMnO4 solution for 15 minutes, then rinse them. Place the seeds in seedling trays filled with pre-sterilized substrate soil. To ensure germination rate, place 2 seeds in each seedling hole. Place the seedling trays in a glass room, controlling the ambient temperature at 8–28℃, average daily temperature at 17.7℃, relative humidity at 14%, and light at 10h / d during the seedling stage. Once the two cotyledons of the *Ageratum plantain* seedlings have unfolded, begin spraying with the prepared nutrient solution every 5 days. The control group's seedling trays were kept moist (moisture content around 60%) using laboratory-filtered purified water.

[0034] Test items and methods The formula for determining germination rate is: Germination rate (R)(%) = F / W × 100%, where F is the number of seeds that germinated normally and W is the total number of seeds tested.

[0035] Height, stem diameter, leaf length and thickness: When the two true leaves of the Plantago asiatica seedlings in the seedling tray unfolded, the height, stem diameter, number of leaves, leaf length and thickness of 10 representative Plantago asiatica seedlings from different groups were measured every 5 days using vernier calipers, and the average value was calculated. The height of the seedlings was measured from the soil surface to the highest leaf or stem tip.

[0036] Data processing: Excel and DPS were used for data statistics and analysis.

[0037] The following nine sets of experiments will further illustrate the methods of this application for each of the nine sets of experiments conducted on *Ageratum tectorum* leaves.

[0038] Experiment 1 Prepare a nutrient solution, including Hoagland nutrient solution. After the two cotyledons of the plantain seedlings have unfolded, spray the prepared nutrient solution onto the leaves and stem tips of the seedlings using a spray bottle, once every 5 days.

[0039] Experiment 2 Unlike Experiment 1, the nutrient solution in this experiment included Hoagland nutrient solution and auxin, with the auxin concentration being 0.005 mg / L.

[0040] Experiment 3 Unlike Experiment 1, the nutrient solution in this experiment included Hoagland nutrient solution and auxin, with the auxin concentration being 0.01 mg / L.

[0041] Experiment 4 Unlike Experiment 1, the nutrient solution used in this experiment included Hoagland nutrient solution and mepiquat chloride, with a concentration of 0.005 mg / L.

[0042] Experiment 5 Unlike Experiment 1, the nutrient solution in this experiment included Hoagland nutrient solution, auxin, and chlormequat chloride. The concentration of auxin was 0.005 mg / L, and the concentration of chlormequat chloride was 0.005 mg / L.

[0043] Experiment Six Unlike Experiment 1, the nutrient solution in this experiment included Hoagland nutrient solution, auxin, and chlormequat chloride. The concentration of auxin was 0.01 mg / L, and the concentration of chlormequat chloride was 0.005 mg / L.

[0044] Experiment 7 Unlike Experiment 1, the nutrient solution used in this experiment included Hoagland nutrient solution and mepiquat chloride, with a concentration of 0.01 mg / L.

[0045] Experiment 8 Unlike Experiment 1, the nutrient solution in this experiment included Hoagland nutrient solution, auxin, and chlormequat chloride. The concentration of auxin was 0.005 mg / L, and the concentration of chlormequat chloride was 0.01 mg / L.

[0046] Experiment Nine Unlike Experiment 1, the nutrient solution in this experiment included Hoagland nutrient solution, auxin, and chlormequat chloride. The concentration of auxin was 0.01 mg / L, and the concentration of chlormequat chloride was 0.01 mg / L.

[0047] control group Unlike Experiment 1, this experiment did not spray nutrient solution, but only an equal amount of water.

[0048] The state of *Ageratum cyrtonema* from Experiments 1 to 9 was measured at different time points and compared with the state of *Ageratum cyrtonema* from the control group at different time points.

[0049]

[0050] Table 2. Germination rate of Plantago asiatica seeds in the first 5 days for each experiment and control group. As shown in Table 2, the germination rates of Experiments 1 to 9 and the control group were all between 86.3% and 90.1%, with no significant difference, indicating that this application does not affect the normal germination of Plantago asiatica seeds.

[0051]

[0052] Table 3. Plant height (cm) of *Ageratum spectabile* seedlings at different days in the experimental and control groups. As shown in Table 3, the plant height of the experiments with added mepiquat chloride (Experiments 4-9) was significantly lower than that of the control group and the experiments with only added auxin (Experiments 2 and 3). In Experiment 7, the plant height was 31.0% lower than the control group at 25 days, effectively inhibiting excessive growth. Experiment 7 showed the lowest plant height within 5-25 days after emergence, with a 31.0% reduction in height compared to the control group at 25 days. Experiment 8 showed an overall plant height reduction of 9.1% compared to the control group. Experiment 9, compared to Experiment 5, significantly increased the growth rate of plant height, with a 19.5% increase in plant height at 25 days after emergence. Therefore, it is evident that auxin has a significantly greater effect on plant height than mepiquat chloride.

[0053]

[0054] Table 4. Stem diameter (mm) of *Ageratum cyrtonema* seedlings at different days in the experimental and control groups. As shown in Table 4, the stem diameter of the experimental group treated with only auxin was significantly smaller than that of the control group, and the stem diameter gradually decreased with increasing concentration. Experiments 5 to 9 significantly increased the stem diameter of *Ageratum plantain* seedlings after the application of chlormequat chloride. Among them, Experiment 7 had the largest stem diameter, increasing by 23.4% compared to the control group, and the plants were more robust. This demonstrates that the application of chlormequat chloride significantly increased the stem diameter of *Ageratum plantain*, effectively enhancing the stem strength of seedlings.

[0055]

[0056] Table 5. Average number of leaves on different days for *Ageratum cyrtonema* seedlings in each experiment and control group.

[0057] Table 6. Leaf thickness (mm) of *Ageratum spectabile* seedlings at different days in the experimental and control groups. As shown in Tables 5 and 6, auxin and mepiquat chloride had no significant effect on the number of leaves in *Ageratum tectorum* seedlings (Table 5), but significantly affected leaf thickness (Table 6). The treatment with mepiquat chloride significantly increased the leaf thickness of *Ageratum tectorum* seedlings compared to the control group, Experiment 1, Experiment 2, and Experiment 3. Specifically, Experiments 7, 8, and 9 showed leaf thickness increases of 36.5%, 28.8%, and 13.1% respectively compared to the control group 25 days after emergence. Experiments 1, 2, and 3 showed leaf thickness decreases of 3.8%, 13.5%, and 21.5% respectively compared to the control group 25 days after emergence.

[0058]

[0059] Table 7. Leaf length (mm) of *Ageratum spectabile* seedlings at different days in the experimental and control groups. As shown in Table 7, auxin significantly increased the leaf length of *Ageratum plantain* seedlings. In Experiments 2 and 3, the average leaf length increased by 8.3% and 16.0% respectively compared to the control group 25 days after emergence. However, mepiquat chloride had no significant effect on the average leaf length. In Experiment 9, the average leaf length increased by 6.6% compared to Experiment 5 25 days after emergence. This indicates that, under the same formulation ratio, auxin has a greater effect on the average leaf length of *Ageratum plantain* seedlings than mepiquat chloride. There was no significant difference in average leaf length between Experiments 8 and 9 25 days after emergence.

[0060] Taking into account the need for robust seedlings of Plantago asiatica, and considering the comprehensive indicators of seedling height, stem diameter, number of leaves, leaf thickness and leaf length, Experiment 8 (0.005 mg / L auxin + 0.01 mg / L chlormequat chloride) is the most ideal nutrient solution ratio.

[0061] Although several specific embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are merely exemplary and should not be construed as limiting the scope of protection of the present invention. Any non-substantial changes and substitutions made by those skilled in the art are within the scope of protection claimed by the present invention.

Claims

1. A nutrient solution for cultivating Plantago asiatica, characterized in that: It includes Hoagland nutrient solution, auxin, and plant growth retardant, wherein the concentration of the auxin is 0–0.01 mg / L and the concentration of the plant growth retardant is 0.005–0.01 mg / L.

2. The nutrient solution for cultivating Plantago asiatica leaves according to claim 1, characterized in that: The concentration of the auxin is 0.005 mg / L.

3. The nutrient solution for cultivating Plantago asiatica leaves according to claim 1, characterized in that: The concentration of the plant growth retardant is 0.01 mg / L.

4. The nutrient solution for cultivating Plantago asiatica leaves according to claim 1, characterized in that: The auxin includes either naphthaleneacetic acid or indolebutyric acid.

5. The nutrient solution for cultivating Plantago asiatica leaves according to claim 1, characterized in that: The plant growth retardant includes one of chlormequat chloride, paclobutrazol, or chlormequat chloride.

6. A method for cultivating *Ageratum cyrtonema* leaves, characterized in that, The procedure includes the following steps: taking seedlings of Plantago asiatica and periodically spraying the nutrient solution described in any one of claims 1 to 5 onto the seedlings for cultivation, thereby obtaining cultured Plantago asiatica seedlings.

7. The method for cultivating *Ageratum cyrtonema* leaves according to claim 6, characterized in that, The plantlets of *Artemisia argyi* were obtained by sterilizing plump *Artemisia argyi* seeds and then cultivating them in a seedling substrate.

8. The seedling cultivation method for *Ageratum cyrtonema* leaf culture according to claim 6, characterized in that: The plantlet seedlings of *Ageratum truncatum* have unfolded two cotyledons.

9. The seedling cultivation method for *Ageratum cyrtonema* leaf culture according to claim 6, characterized in that: The frequency of regular spraying is once every 4 to 6 days.

10. A method for cultivating *Ageratum cyrtonema* leaves according to claim 6, characterized in that: The nutrient solution is periodically sprayed onto the leaves and stem tips of the *Ageratum truncatum* seedlings.

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