A cultivation method for improving the propagation efficiency of rhodiola crenulata

Abstract

The application discloses a kind of cultivation methods for improving the propagation efficiency of Rhodiola crenulata, and relates to the technical field of plant cultivation and seed breeding.The cultivation method comprises the following steps: (1) seedling stage: after seed hormone soaking treatment, seed is sown in light substrate, and strong seedling is obtained after 6-12 months of cultivation; (2) water culture planting and flower induction stage: the strong seedling is transplanted to the water culture system, and the photoperiod is induced by using artificial light source with a red-blue spectrum ratio of 1:1, combined with periodic adjustment of nutrient solution and exogenous hormone spraying, to induce reproductive growth; (3) pollination and seed harvesting stage: seed is harvested after assisted pollination.The application shortens the period from seed to seed of Rhodiola crenulata from more than 6 years in the traditional way to 2-3 years through multi-factor synergistic regulation, significantly improves the flowering rate and seed yield per plant, and increases the propagation efficiency by more than 99%.The application is suitable for different ecological types of seed source, and has the advantages of strong operability and good universality.

Description

Technical Field

[0001] This invention relates to the field of plant cultivation and seed propagation technology, specifically to a cultivation method for improving the seed propagation efficiency of Rhodiola rosea, which is particularly suitable for shortening the reproductive growth cycle of Rhodiola rosea and increasing seed yield. Background Technology

[0002] Rhodiola rosea ( Rhodiola crenulata (Hook. f. & Thomson) H. Ohba is a perennial herb belonging to the genus Rhodiola in the family Crassulaceae. It is mainly distributed in alpine scree slopes and meadows at altitudes of 4000-6000 meters in Tibet, Sichuan, and Qinghai, my country. Rhodiola grandiflora possesses various pharmacological effects, including invigorating qi and blood circulation, resisting hypoxia, combating fatigue, and antioxidation, and is known as "plateau ginseng." It has a long history of use in traditional Chinese medicine and Tibetan medicine. The Chinese Pharmacopoeia (2025 edition) stipulates that the dried root and rhizome of Rhodiola grandiflora are the only medicinal source species for Rhodiola. Furthermore, according to the National Key Protected Wild Plants List (2021 edition), many plants in the genus Rhodiola are listed as national second-class protected plants.

[0003] With the surge in market demand, wild Rhodiola rosea resources have been drastically reduced due to over-harvesting, resulting in a significant drop in population density and endangerment in some areas. Therefore, the artificial cultivation of Rhodiola rosea from wild to domestic is an inevitable trend. However, Rhodiola rosea has an extremely long growth period, requiring more than 10 years to flower and bear fruit in the wild, and even under conventional field cultivation conditions, it takes more than 6 years to enter the reproductive growth period. Current artificial cultivation techniques mostly adopt direct seeding or seedling transplanting, which have the following significant drawbacks: (1) The growth cycle is too long, resulting in a long investment return cycle and low industry attractiveness; (2) The field environment (such as temperature, light, and water) is uncontrollable, and the flowering and fruiting rates are low and unstable; (3) Seed yield and quality fluctuate greatly, making it difficult to meet the urgent needs of large-scale planting and industrial development. Although existing technologies such as CN115530058A disclose a hydroponic method using sandy substrates in paddy fields, they focus on nutrient solution replacement and lack systematic regulation of flowering induction; while CN101946709A relies on transplanting in the wild and natural temperature differences, without involving active intervention to promote flowering. Therefore, developing a cultivation method that can significantly shorten the cultivation period, rapidly and stably induce flowering, and improve propagation efficiency is of great significance for protecting wild resources and ensuring the sustainable use of medicinal materials. Summary of the Invention

[0004] In view of the technical bottlenecks in the existing technology of Rhodiola rosea, such as long flowering cycle (≥6 years), low flowering and fruiting rate, and low seed propagation efficiency, the purpose of this invention is to provide a cultivation method to improve the seed propagation efficiency of Rhodiola rosea. This method can shorten the complete cycle of Rhodiola rosea from seed to seed harvest to 2-3 years, and significantly improve the flowering rate and seed yield per plant.

[0005] To achieve the above objectives, the present invention provides the following technical solution: A cultivation method to improve the propagation efficiency of Rhodiola rosea includes the following steps: (1) Seedling stage: Select mature and plump Rhodiola rosea seeds, treat the Rhodiola rosea seeds with hormones and then sow them in a light substrate. Cultivate for 6 to 12 months to obtain strong seedlings that meet the standards. (2) Hydroponic planting and flower induction stage: The strong seedlings are transplanted into the hydroponic system and photoperiod induction is carried out using an artificial light source with a red-blue spectrum ratio of 1:1. Combined with the phased adjustment of the nutrient solution formula and the spraying of exogenous hormones, the plants are synergistically induced to enter the reproductive growth period. The specific operation of the photoperiod induction includes: maintaining a photoperiod of 12 hours of light / 12 hours of darkness during the seedling establishment period, maintaining a photoperiod of 16 hours of light / 8 hours of darkness during the vegetative growth period, and shortening the photoperiod to 12 hours of light / 12 hours of darkness after entering the induction flowering period. The phased adjustments to the nutrient solution formula include: During the vegetative growth period, use a high-nitrogen nutrient solution with a mass ratio of N, P2O5, and K2O of 20~30:5~10:5~10. During the induction of flowering, switch to a high phosphorus and potassium nutrient solution with a mass ratio of N, P2O5, and K2O of 10~15:20~30:10~20, and add boron fertilizer to the nutrient solution at a final concentration of 0.5~1.0 mg / L. The exogenous hormone spraying includes: 20-30 days before the plant buds appear, mixing 10-25 mg / L of cytokinin with 5-10 mg / L of naphthaleneacetic acid at a final concentration, then adding 0.1-0.3 wt% potassium dihydrogen phosphate, 0.06-0.1 wt% boric acid, 0.1-0.2 wt% chelated calcium and 0.05-0.15 wt% magnesium sulfate to prepare a mixed flower-promoting spray solution. Spray the whole plant at 16:00-18:00 in the evening, spraying 1-2 times every 10-15 days, for 2-3 consecutive cycles. (3) Pollination and seed collection stage: Assisted pollination is carried out during the flowering period of the plant, and the seeds are harvested after they mature.

[0006] Preferably, in step (1), mature and plump Rhodiola rosea seeds weighing ≥0.16g are selected.

[0007] Preferably, in step (1), the hormone soaking treatment includes: soaking the seeds for 12 to 24 hours in a mixed aqueous solution of gibberellin with a final concentration of 100 to 200 mg / L and ABT rooting powder with a final concentration of 50 to 100 mg / L.

[0008] Preferably, in step (1), the lightweight substrate is a mixture of peat moss, perlite, and vermiculite in a volume ratio of 2~3:0.5~1:0.5~1, with a pH value of 6.5~7.5; and / or, the environmental conditions during the cultivation process include: daytime temperature of 20~25℃, nighttime temperature of 12~15℃, and light intensity of 200~300 μmol·m -2 ·s -1 The photoperiod is 12-16 hours of light / 8-12 hours of darkness.

[0009] Preferably, in step (1), the standard for strong seedlings is: plant height 6~12 cm, stem diameter ≥0.3 cm, number of true leaves 4~8, and the proportion of roots wrapped around the growth substrate reaches more than 20%.

[0010] Preferably, in step (2), the hydroponic system is selected from any one of the deep flow hydroponic system, the tidal hydroponic system, or the nutrient film hydroponic system.

[0011] More preferably, in step (2), the light intensity of the artificial light source is controlled to be 200~400 μmol·m⁻¹. -2 ·s -1 The photoperiod-induced temperature management includes: daytime temperature of 20~25℃, nighttime temperature of 12~15℃, and the daytime-night temperature difference controlled at 8~10℃.

[0012] More preferably, in step (2), the light intensity of the artificial light source during the seedling establishment period is 200~250 μmol·m⁻¹. -2 ·s -1 During the vegetative growth and flowering induction periods, the light intensity of the artificial light source is 350~400 μmol·m⁻¹. -2 ·s -1 .

[0013] Preferably, in step (2), during the vegetative growth period and the induced flowering period, the conductivity of the high-nitrogen nutrient solution and the high-phosphorus-potassium nutrient solution is controlled at 800~1500 μS / cm, the pH value is controlled at 5.8~6.5, the dissolved oxygen content is 4~8 mg / L, and the high-nitrogen nutrient solution and the high-phosphorus-potassium nutrient solution are replaced every 14 days.

[0014] Preferably, the cytokinin is 6-BA.

[0015] Preferably, in step (3), the auxiliary pollination method includes one or more combinations of artificial mechanical vibration of the plant, wind-assisted pollination, or release of bumblebees for pollination.

[0016] Compared with the prior art, the present invention has the following outstanding advantages: Firstly, it significantly shortens the flowering cycle: Through the synergistic effect of multiple factors, including integrated tray seedling cultivation, precise hydroponic environment control, photoperiod induction, phased adjustment of nutrient solution (switching from high-nitrogen to high-phosphorus-potassium), and exogenous hormone spraying at specific times, it achieves, for the first time, precise artificial control over the complete life cycle of Rhodiola rosea. (See Example 1 and...) Figure 3 , Figure 4 As shown, traditional field cultivation requires more than 6 years and no flowering ( Figure 4 Using the method of this invention, about 30% of the plants can flower in the first year of hydroponics, greatly shortening the cycle of Rhodiola rosea from seed sowing to flowering and fruiting from more than 6 years in field cultivation to 2-3 years, and as fast as only 2 years (6 months of seedling cultivation in plug trays + 1.5 years of hydroponic induction).

[0017] Secondly, it significantly improves propagation efficiency: Thanks to the close connection and parameter optimization of each stage of "promoting vegetative growth - inducing flowering - assisting pollination," the method of this invention greatly improves the population flowering rate and individual seed yield of Rhodiola rosea. Example 1 shows that under a deep-flow hydroponic system, the population flowering rate in the second year is close to 60%, and is expected to reach over 90% in the third year, with an individual seed yield as high as 0.01~0.3g; under the tidal hydroponic system of Example 2, the flowering rate in the third year can also reach 60%~70%. Overall, the propagation efficiency of the method of this invention is improved by more than 99%, effectively breaking through the bottleneck of seed source restricting the artificial cultivation of Rhodiola rosea.

[0018] Thirdly, it boasts strong systematicity and operability: This invention provides a complete, closed-loop technical solution from seed treatment and seedling cultivation to hydroponic flowering promotion, pollination, and seed collection, and clearly quantifies the core parameters at each stage. In particular, it provides specific equipment specifications and management parameters for different hydroponic systems (deep flow hydroponics, tidal hydroponics), and clarifies key details such as the timing of photoperiod switching, nutrient solution formula switching points, and the precise ratio and frequency of exogenous hormone spraying. This overcomes the shortcomings of existing technologies, such as single flowering promotion methods, missing parameters, and poor repeatability, making this method highly suitable for industrial application under different production conditions.

[0019] Fourth, it has wide applicability: as in Example 3 and Figure 7As shown, the method of this invention can achieve a significant flowering-promoting effect of 27%–30% in the first year and 55%–63% in the second year for various ecotypes of Rhodiola rosea collected from different producing areas such as Tibet, Sichuan, and Qinghai. This indicates that the method is not limited by the ecotype of the seed source, has strong universality, and is easy to promote in different regions, providing a reliable technical path for the artificial domestication and sustainable utilization of endangered medicinal plants. Attached Figure Description

[0020] The accompanying drawings, which are included to provide a further understanding of the invention and form part of this invention, illustrate exemplary embodiments of the invention and are used to explain the invention, but do not constitute an undue limitation of the invention. In the drawings: Figure 1 Images of the cultivation trough and plant growth status of the deep flow hydroponics (DFT) system in Embodiment 1 of the present invention.

[0021] Figure 2 This is a close-up image of a large-flowered Rhodiola rosea plant in the hydroponic flowering period according to Embodiment 1 of the present invention. A is a hydroponic large-flowered Rhodiola rosea plant, and the area indicated by the red dotted circle is the flower bud. B is a magnified view of the flower bud opening.

[0022] Figure 3 This is a bar chart comparing the flowering rate of Rhodiola rosea plant populations under different cultivation years in Example 1 of the present invention. a, b, and c are multiple comparison significance markers after analysis of variance (ANOVA), tested using Duncan's method: different lowercase letters indicate statistical significance at the P < 0.05 level; the same letter indicates no significant difference between groups. Figure 3 If they are labeled a, b, and c respectively, it indicates that there is a significant difference between any two groups (P < 0.05).

[0023] Figure 4 This image shows a traditional field-grown Rhodiola rosea failing to bloom for six years.

[0024] Figure 5 This image shows the flowering phenotype of approximately 60% of a large-flowered Rhodiola rosea plant population grown hydroponically using the method of this invention in its second year.

[0025] Figure 6 Images of the cultivation rack and plant growth status of the tidal hydroponic system in Embodiment 2 of the present invention.

[0026] Figure 7 This is a bar chart comparing the flowering rates of different ecotypes of Rhodiola rosea after applying the method of this invention in Example 3 of this invention. Detailed Implementation

[0027] In this embodiment of the invention, the standard for robust seedlings is: plant height 6-12 cm, stem diameter ≥0.3 cm, number of true leaves 4-8, and well-developed root system, where well-developed root system means that the proportion of roots entwined with the growth substrate reaches more than 20%.

[0028] In the description of this invention, it should be noted that unless specific conditions are specified in the examples, conventional conditions or conditions recommended by the manufacturer shall apply. Reagents or instruments whose manufacturers are not specified are all commercially available products.

[0029] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0030] Example 1: Optimized propagation method based on deep flow hydroponics (DFT) system This embodiment demonstrates a deep-flow hydroponic method for improving the propagation efficiency of Rhodiola rosea, the system of which is as follows: Figure 1 As shown in the figure. This method is particularly suitable for the hydroponic management of perennial plants with a longer vegetative growth period.

[0031] 1. Equipment and System Parameters Cultivation trough: The cultivation trough is made of PVC material and has a size of 200 cm (length) × 100 cm (width) × 10 cm (depth). Planting holes with a diameter of 5 cm are made on the trough cover plate at a plant spacing of 20 cm × 20 cm.

[0032] Planting board: Use 3-5 cm thick polystyrene foam board as the planting board, and match the opening position of the opening to the cultivation trough cover.

[0033] Nutrient solution and oxygenation: The nutrient solution depth in the cultivation tank is maintained at 5-8 cm, and water lost due to evaporation and transpiration is automatically replenished through a float valve. Continuous oxygenation is performed 24 hours a day using an air pump and evenly distributed air stones (density 1-2 stones / m³) to ensure the dissolved oxygen content in the nutrient solution is 6 mg / L.

[0034] Automatic monitoring system (commercially available): The system integrates online automatic monitoring and feedback control equipment for EC / pH, which can monitor the status of nutrient solution in real time. When EC or pH deviates from the set value (EC 1200 μS / cm, pH 6.0), it automatically replenishes the mother liquor or acid-base adjustment solution to maintain the high stability of the nutrient solution composition.

[0035] Deep flow hydroponics (DFT) is a highly efficient and technologically mature hydroponic method. This paper only briefly introduces the main components of the DFT system used in this invention and does not constitute a limitation on the solution of this invention. Any equipment that can realize the DFT hydroponic method can be used in this invention.

[0036] 2. Cultivation Steps Seedling raising and transplanting: Select mature and plump Rhodiola rosea seeds weighing ≥0.16g (provided by Tibet Nodikang Pharmaceutical Co., Ltd.). Soak the seeds in a mixed aqueous solution of gibberellin (final concentration 150 mg / L) and ABT rooting powder (final concentration 80 mg / L) for 20 hours. After hormone treatment, sow the seeds in seed trays filled with a lightweight substrate. The lightweight substrate is a mixture of peat moss, perlite, and vermiculite in a volume ratio of 3:1:1, with a pH of 7.1. The optimal conditions are a daytime temperature of 20-25℃, a nighttime temperature of 12-15℃, and a light intensity of 200-300 μmol·m⁻². -2 ·s -1 Strong seedlings were obtained by cultivating them for 6 months under a controlled environment with a photoperiod of 16 hours of light / 8 hours of darkness.

[0037] Hydroponic transplanting and flower induction stage: Remove robust seedlings, immerse their roots through the planting hole into the nutrient solution, and gently secure them at the base of the stem with a sponge. Use an artificial light source with a red-to-blue spectral ratio of 1:1 (red light wavelength 660 nm, blue light wavelength 450 nm) for photoperiodic induction, combined with phased adjustments to the nutrient solution formula and the application of exogenous hormones, to synergistically induce the plants into the reproductive growth stage. Details are as follows: Lighting setup: LED light strips are suspended 35 cm above the cultivation trough. The red-to-blue spectral ratio of the light source is 1:1 (red light wavelength 660 nm, blue light wavelength 450 nm), and the photon flux density is set to 200-400 μmol·m⁻¹. -2 ·s -1 .

[0038] Management during the seedling establishment period: The first two weeks after transplanting are the seedling establishment period, during which the light intensity is set at 200 μmol·m⁻². -2 ·s -1 The photoperiod was set to 12 hours of light / 12 hours of darkness. The high-nitrogen nutrient solution (nitrogen, phosphorus, and potassium mass ratio: 20:10:10, pH 6.2) had an EC value controlled at 1000 μS / cm. After this stage, the seedling survival rate could reach over 90%.

[0039] Vegetative growth period management (Year 1): After the seedling establishment period, the plant enters the vegetative growth period. Use an LED light source with a red-to-blue spectrum ratio of 1:1, increasing the light intensity to 400 μmol·m⁻². -2 ·s -1The photoperiod was restored to 16 hours of light / 8 hours of darkness. A high-nitrogen nutrient solution with a N:P₂O₅:K₂O mass ratio of 20:10:10 was used, with the EC value maintained at 1200 μS / cm and the pH value at 6.5. The goal at this stage was to promote root and stem enlargement and biomass accumulation.

[0040] Management during the induction of flowering (from the second year onwards): Move the cultivation racks back to the normal cultivation environment. Starting in spring, adjust the photoperiod to 12 hours of light / 12 hours of darkness, maintaining a light intensity of 400 μmol·m⁻¹. -2 ·s -1 The nutrient solution was replaced with a high-phosphorus and potassium-rich flower-promoting nutrient solution with a N:P2O5:K2O mass ratio of 10:30:20, and 0.8 mg / L borax was added. The EC value was maintained at 1200 μS / cm, and the pH value was controlled at 5.9. The solution was changed every 14 days. When flower bud differentiation was observed (25 to 30 days before budding), the plant was sprayed twice every 15 days with a "flower-promoting spray solution" in the morning and evening: 20 mg / L of cytokinin 6-BA and 5 mg / L of naphthaleneacetic acid were mixed to a final concentration, and then 0.2 wt% potassium dihydrogen phosphate, 0.08 wt% boric acid, 0.15 wt% chelated calcium, and 0.1 wt% magnesium sulfate were added and mixed. This mixture was sprayed for two consecutive cycles.

[0041] Temperature control during the seedling establishment period, vegetative growth period, and flowering induction period includes: daytime temperature of 20-25℃, nighttime temperature of 12-15℃, and a day-night temperature difference of 8-10℃.

[0042] Key management points: Test EC / pH weekly, supplement trace elements (Fe-EDTA 20~30 mg / L, etc.) monthly, and prune withered and yellow leaves in a timely manner.

[0043] Pollination and seed collection stage: After the inflorescence emerges, blow the plant with a turbine blower 2-3 times a day to assist pollination, thereby improving the cross-pollination rate and seed quality. Harvest the seeds 40-50 days after flowering, when they turn from red to brown. After the inflorescence is cut off, place it in a collection net for after-ripening and drying. Figure 2 Images of Rhodiola rosea plants in the hydroponic flowering stage are provided. Image A shows a large number of flower buds on the hydroponic Rhodiola rosea plant, while Image B shows the flowering state of the flower buds.

[0044] 3. Propagation effect like Figure 3 As shown, using the optimized method of this embodiment, the flowering rate of the hydroponic plant population reached 30.1% in the first year and 59.7% in the second year (flowering phenotype as shown). Figure 5 (As shown). This result is attributed to the cultivation method in this embodiment, which provides a more suitable growth state, a more stable root environment, and an efficient pollination method, with a single seed weight of 0.01g~0.3g. Figure 4 The images provided are for comparison, showing that traditionally planted Rhodiola rosea in the field does not flower for 6 years; the flowering rate after 6 years is only about 0.3%. Figure 3 Compared with the results of hydroponics in the first and second years of this embodiment, the propagation efficiency increased by approximately 99%-198%.

[0045] The traditional field planting process is as follows: Select sandy loam or loam soil with an altitude of 3500 m, cool climate, and good drainage. Deep plow to a depth of 30 cm, and make ridges along the slope, 100 cm wide and 20 cm high. Apply compound fertilizer (N-P2O5-K2O mass ratio: 15:15:15) at 500 kg / ha as base fertilizer during land preparation. Sow seeds in March or April at a rate of 1.5-2.0 g / m², cover with 2-3 mm of fine soil, and cultivate for one year while maintaining moisture and shade. Select healthy one-year-old seedlings and transplant them in autumn after the above-ground parts have withered or in the following spring before they turn green again. Make furrows with a row spacing of 20 cm and a plant spacing of 20 cm, place the seedlings with the terminal bud facing upwards at an angle, cover with 6 cm of soil and lightly compact. During the growing season, maintain field water holding capacity at 60%-70%, loosen the soil, remove weeds, and dig drainage ditches in a timely manner. Apply urea at 75-150 mg / ha depending on the seedling condition. kg / ha, after the above-ground parts wither before winter, cover with 5 cm of soil for frost protection; after 6 years of continuous planting, harvest the seeds of flowering plants.

[0046] Example 2: Rapid propagation method based on tidal hydroponic system This embodiment demonstrates a rapid hydroponic propagation method for Rhodiola rosea to improve propagation efficiency. The system is as follows: Figure 6 As shown.

[0047] 1. Equipment and System Parameters Cultivation rack: A multi-layer three-dimensional cultivation rack is adopted, with each layer being 50 cm high.

[0048] Tidal cultivation tube: 200 cm (length) × 6 cm (width) × 6 cm (height), with a slight slope of 2° to facilitate nutrient solution reflux.

[0049] Planting containers: Use funnel-shaped planting cups that come with a 1 / 4-inch tube, with dimensions of 15 cm high × 8 cm top diameter × 4 cm bottom diameter. A 5 mm diameter ventilation hole should be made at the top 1 / 10 of the cup. Maintain a 20 cm spacing between containers.

[0050] Nutrient solution and oxygenation: Maintain the nutrient solution depth in the planting cups at 5-8 cm, and automatically replenish water lost through evaporation and transpiration using a float valve. Use an air pump and evenly distributed air stones (density 1-2 stones / m³) for continuous 24-hour oxygenation to ensure the dissolved oxygen content in the nutrient solution is 6 mg / L.

[0051] Liquid supply and circulation system: Equipped with a water pump with a flow rate of 10~15 L / min. The tidal irrigation cycle is set to flood for 15 minutes, drain for 45 minutes, and circulate once every 2 hours.

[0052] Automatic monitoring system (commercially available): The system integrates online automatic monitoring and feedback control equipment for EC / pH, which can monitor the status of nutrient solution in real time. When EC or pH deviates from the set value (EC 1200 μS / cm, pH 6.0), it automatically replenishes the mother liquor or acid-base adjustment solution to maintain the high stability of the nutrient solution composition.

[0053] The tidal hydroponic system is a hydroponic technology that mimics the ocean tide phenomenon in the natural environment. This article only briefly introduces the main components of the tidal hydroponic system used in this invention, and does not constitute a limitation on the solution of this invention. Any equipment that can realize the tidal hydroponic method can be used in this invention.

[0054] 2. Cultivation Steps Seedling raising and transplanting: Select mature and plump Rhodiola rosea seeds weighing ≥0.16g (provided by Tibet Nodikang Pharmaceutical Co., Ltd.). Soak the seeds in a mixed aqueous solution of gibberellin (final concentration 150 mg / L) and ABT rooting powder (final concentration 80 mg / L) for 20 hours. After hormone treatment, sow the seeds in seed trays filled with a lightweight substrate. The lightweight substrate is a mixture of peat moss, perlite, and vermiculite in a volume ratio of 3:1:1, with a pH of 7.1. The optimal conditions are a daytime temperature of 20-25℃, a nighttime temperature of 12-15℃, and a light intensity of 200-300 μmol·m⁻². -2 ·s -1 Strong seedlings were obtained by cultivating them for 6 months under a controlled environment with a photoperiod of 16 hours of light / 8 hours of darkness.

[0055] Hydroponic transplanting and flower induction stage: Remove strong seedlings and carefully rinse the roots of the substrate with clean water. Transplant the seedlings into funnel-shaped planting cups, one seedling per cup, and use expanded clay pebbles to fill and secure the base of the plant. Use an artificial light source with a red-to-blue spectral ratio of 1:1 (red light wavelength 660 nm, blue light wavelength 450 nm) for photoperiodic induction, combined with phased adjustments to the nutrient solution formula and the application of exogenous hormones, to synergistically induce the plants to enter the reproductive growth stage. Details are as follows: Lighting setup: LED light strips are suspended 35 cm above the cultivation trough. The red-to-blue spectral ratio of the light source is 1:1 (red light wavelength 660 nm, blue light wavelength 450 nm), and the photon flux density is set to 200-400 μmol·m⁻¹. -2 ·s -1 .

[0056] Management during the seedling establishment period: The first two weeks after transplanting are the seedling establishment period, during which the light intensity should be reduced to 200 μmol·m⁻². -2·s -1 The photoperiod was set to 12 hours of light / 12 hours of darkness. The EC value of the high-nitrogen nutrient solution (N:P:K mass ratio: 20:10:10, pH 6.3) was controlled at 1000 μS / cm. After this stage, the seedling survival rate could reach over 90%.

[0057] Vegetative growth period management (Year 1): After the seedling establishment period, the plant enters the vegetative growth period. Use an LED light source with a red-to-blue spectrum ratio of 1:1, increasing the light intensity to 400 μmol·m⁻². -2 ·s -1 The photoperiod was restored to 16 hours of light / 8 hours of darkness. A high-nitrogen nutrient solution with a N:P₂O₅:K₂O mass ratio of 20:10:10 was used, with the EC value maintained at 1200 μS / cm and the pH value at 6.0. The goal at this stage was to promote root and stem enlargement and biomass accumulation.

[0058] Management during the induction of flowering (from the second year onwards): Move the cultivation racks back to the normal cultivation environment. Starting in spring, adjust the photoperiod to 12 hours of light / 12 hours of darkness, maintaining a light intensity of 400 μmol·m⁻¹. -2 ·s -1 The nutrient solution was replaced with a high-phosphorus and potassium-rich flower-promoting nutrient solution with a N:P2O5:K2O mass ratio of 10:30:20, and 0.8 mg / L of borax was added. The EC value was maintained at 1200 μS / cm, and the pH value was controlled at 6.5. The solution was changed every 14 days. When flower bud differentiation was observed (25 to 30 days before budding), the plant was sprayed twice every 15 days with a "flower-promoting spray solution" in the morning and evening: 25 mg / L of cytokinin 6-BA and 10 mg / L of naphthaleneacetic acid were mixed to a final concentration, and then 0.2 wt% potassium dihydrogen phosphate, 0.08 wt% boric acid, 0.15 wt% chelated calcium, and 0.1 wt% magnesium sulfate were added and mixed. This mixture was sprayed for two consecutive cycles.

[0059] Temperature control during the seedling establishment period, vegetative growth period, and flowering induction period includes: daytime temperature of 20-25℃, nighttime temperature of 12-15℃, and a day-night temperature difference of 8-10℃.

[0060] Key management points: Test EC / pH weekly, supplement trace elements (Fe-EDTA 20~30 mg / L, etc.) monthly, and prune withered and yellow leaves in a timely manner.

[0061] Pollination and seed collection stage: After the inflorescence emerges, blow the plant with a turbine blower 2-3 times a day to assist pollination, thereby improving the cross-pollination rate and seed quality. Harvest the seeds 40-50 days after flowering, when they turn from red to brown. After the inflorescence is cut off, place it in a collection net for after-ripening and drying.

[0062] 3. Propagation effect Using the method described in this embodiment, the flowering rate of the plants reached 30%~40% in the second year and 60%~70% in the third year. The seed yield per plant was 0.01~0.3 g. Compared with the flowering rate of approximately 0.3% after 6 years of traditional field cultivation of Rhodiola rosea in the second and third years of this embodiment, the propagation efficiency was increased by approximately 99%-232%.

[0063] Example 3: Adaptive cultivation of Rhodiola rosea of ​​different ecotypes To verify the universality of the method of this invention, seeds of three different ecotypes of wild Rhodiola rosea were selected from Linzhi, Tibet; Ganzi, Sichuan; and Yushu, Qinghai, respectively. Cultivation experiments were conducted according to the DFT system and management process described in Example 1, with an experimental period of 2 years. The results showed that all three ecotypes of seed sources achieved a flowering rate of 27-30% in the first year of hydroponics and 55-63% in the second year. Figure 7 This indicates that the method of the present invention has broad applicability to different geographical sources of Rhodiola rosea, and the technical solution is stable and reliable.

[0064] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents. The embodiments described above merely illustrate several implementations of the invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention. It should be noted that those skilled in the art can make several modifications and improvements without departing from the concept of the invention, and these all fall within the protection scope of the invention. Therefore, the protection scope of this invention should be determined by the appended claims.

Claims

1. A cultivation method for improving the propagation efficiency of Rhodiola rosea, characterized in that, Includes the following steps: (1) Seedling stage: After the seeds of Rhodiola rosea are treated with hormones, they are sown in a light substrate and cultivated for 6 to 12 months to obtain strong seedlings; (2) Hydroponic planting and flower induction stage: The strong seedlings are transplanted into the hydroponic system and photoperiod induction is carried out using an artificial light source with a red-blue spectrum ratio of 1:

1. Combined with the phased adjustment of the nutrient solution formula and the spraying of exogenous hormones, the plants are synergistically induced to enter the reproductive growth period. The specific operation of the photoperiod induction includes: maintaining a photoperiod of 12 hours of light / 12 hours of darkness during the seedling establishment period, maintaining a photoperiod of 16 hours of light / 8 hours of darkness during the vegetative growth period, and shortening the photoperiod to 12 hours of light / 12 hours of darkness after entering the induction flowering period. The phased adjustments to the nutrient solution formula include: During the vegetative growth period, use a high-nitrogen nutrient solution with a mass ratio of N, P2O5, and K2O of 20~30:5~10:5~10. During the induction of flowering, switch to a high phosphorus and potassium nutrient solution with a mass ratio of N, P2O5, and K2O of 10~15:20~30:10~20, and add boron fertilizer to the nutrient solution at a final concentration of 0.5~1.0 mg / L. The exogenous hormone spraying includes: 20-30 days before the plant buds appear, mixing 10-25 mg / L of cytokinin with 5-10 mg / L of naphthaleneacetic acid at a final concentration, then adding 0.1-0.3 wt% potassium dihydrogen phosphate, 0.06-0.1 wt% boric acid, 0.1-0.2 wt% chelated calcium and 0.05-0.15 wt% magnesium sulfate to prepare a mixed flower-promoting spray solution. Spray the whole plant at 16:00-18:00 in the evening, spraying 1-2 times every 10-15 days, for 2-3 consecutive cycles. (3) Pollination and seed collection stage: Assisted pollination is carried out during the flowering period of the plant, and the seeds are harvested after they mature; In step (2), the artificial light intensity during the seedling establishment period is 200~250 μmol·m⁻². -2 ·s -1 During the vegetative growth and flowering induction periods, the light intensity of the artificial light source is 350~400 μmol·m⁻¹. -2 ·s -1 Furthermore, the photoperiod-induced temperature management includes: daytime temperature of 20~25℃, nighttime temperature of 12~15℃, and the daytime-night temperature difference controlled at 8~10℃.

2. The cultivation method according to claim 1, characterized in that, In step (1), the hormone soaking treatment includes: soaking the seeds for 12 to 24 hours in a mixed aqueous solution of gibberellin with a final concentration of 100 to 200 mg / L and ABT rooting powder with a final concentration of 50 to 100 mg / L.

3. The cultivation method according to claim 1, characterized in that, In step (1), the lightweight matrix is ​​composed of peat moss, perlite, and vermiculite mixed in a volume ratio of 2~3:0.5~1:0.5~1, with a pH value of 6.5~7.5; And / or, the environmental conditions for the cultivation process include: daytime temperature 20–25°C, nighttime temperature 12–15°C, and light intensity of 200–300 μmol·m⁻². -2 ·s -1 The photoperiod is 12-16 hours of light / 8-12 hours of darkness.

4. The cultivation method according to claim 1, characterized in that, In step (1), the standard for strong seedlings is: plant height 6~12 cm, stem diameter ≥0.3 cm, number of true leaves 4~8, and the proportion of roots wrapped around the growth substrate reaches more than 20%.

5. The cultivation method according to claim 1, characterized in that, In step (2), the hydroponic system is selected from any one of the deep flow hydroponic system, tidal hydroponic system or nutrient film hydroponic system.

6. The cultivation method according to claim 1, characterized in that, In step (2), during the vegetative growth period and the induced flowering period, the conductivity of the high-nitrogen nutrient solution and the high-phosphorus-potassium nutrient solution are controlled at 800~1500 μS / cm, the pH value is controlled at 5.8~6.5, the dissolved oxygen content is 4~8 mg / L, and the high-nitrogen nutrient solution and the high-phosphorus-potassium nutrient solution are replaced every 14 days.

7. The cultivation method according to claim 1, characterized in that, The cytokinin is 6-BA.

8. The cultivation method according to claim 1, characterized in that, In step (3), the auxiliary pollination methods include one or more combinations of artificial mechanical vibration of the plant, wind-assisted pollination, or release of bumblebees for pollination.

Images