A method for raising seedlings of a species of hedychium

Abstract

The application discloses a seedling raising method of Hedychium, and belongs to the technical field of plant seedling raising. The method is aimed at the problems of long natural germination period, low germination rate and easy rotting of the Hedychium seed. The method comprises the following steps: soaking the seed in gibberellin solution and continuously soaking the seed in water to break dormancy; sowing the seed on a moss substrate and sealing the moss substrate in a degradable transparent plastic bag to accelerate germination; placing the moss substrate in a variable temperature environment of 20-32 DEG C to accelerate germination in the dark; after the radicle of the seedling grows out, transferring the seedling to a moss substrate to grow under natural light; and transplanting the seedling with the moss substrate after the true leaf grows out. The method shortens the germination time, improves the germination rate to more than 90%, is simple and convenient to operate, low in cost, and applicable to seedling raising of other Hedychium plants, and provides technical support for large-scale production and resource conservation.

Description

Technical Field

[0001] This invention belongs to the field of seedling propagation technology, specifically involving a highly efficient seedling propagation method for Hedysarum seeds using moss as the germination substrate and combining it with a micro-humidity and heat-preserving seedling environment constructed by biodegradable plastic bags. It is suitable for the large-scale propagation of horticultural ornamental plant seeds and the rapid propagation of hybrid offspring. Background Technology

[0002] Yellow ginger flower ( Yellow Hedychium Roxb. (Ginger Lily) is an important material for high-end cut flowers, landscaping, and aromatic plant arrangements due to its vibrant colors, unique flower shape, and rich fragrance. Traditionally, plants in the Ginger Lily genus are mostly propagated by rhizome division, but this method has a low propagation coefficient (usually <5 times per year), and long-term asexual reproduction can easily accumulate viruses and lead to seed degeneration. Seed propagation is the fundamental way to introduce and domesticate species, hybridize and breed, and achieve standardized seed production, which is of great significance for the promotion of new varieties and the preservation of germplasm resources. However, the seed coat structure of plants in this genus is special, with poor water and air permeability, which hinders seed water absorption and normal respiration, leading to germination difficulties; in addition, the seeds of most species have low vigor and weak germination ability. If the seeds are not sown immediately after harvesting, or if they are not kept dry during storage, their vigor will decrease significantly. Experience shows that if the fleshy outer coating of the seed is completely dry before sowing, the germination rate will be very low.

[0003] Existing studies have shown that the germination of seeds of the genus Ginger (such as Hedychium coronarium) is synergistically regulated by temperature, substrate moisture content and aeration, with a narrow germination window and sensitivity to adverse conditions. Currently reported seedling cultivation techniques mostly use perlite, river sand or filter paper as germination beds and place them in petri dishes or constant temperature incubators for controlled germination. However, these methods have obvious drawbacks: (1) Perlite and sand have small specific surface area and low capillary porosity, resulting in insufficient water retention capacity. Under germination conditions at 28℃, water needs to be replenished every 6 to 8 hours, which is cumbersome and easily leads to seed imbibition loss or mold due to imbalance in water management; (2) They rely on special equipment such as constant temperature incubators and artificial climate chambers, which limits the processing capacity per batch. The equipment investment and operating energy consumption are high, making it difficult to promote to ordinary growers or grassroots; (3) Open systems such as petri dishes lose humidity quickly, with relative humidity often below 70%. During seed germination, the osmotic potential fluctuates drastically, resulting in uneven germination and a large span of emergence time, which affects the subsequent seedling consistency management.

[0004] Therefore, existing technologies lack a seed propagation method for ginger lily that maintains a stable high-humidity environment without requiring frequent manual intervention or expensive equipment. Developing a simple, cost-effective, and environmentally friendly method that optimizes water and temperature retention is of practical urgency for improving the efficiency and quality of the ginger lily seedling industry. Summary of the Invention

[0005] To address the shortcomings of the existing technology, this invention provides a method for raising seeds of the genus *Hedychium*. This method utilizes the efficient water absorption and retention properties of the moss substrate and the sealing, moisturizing, and warming effect of the transparent plastic bag to form a self-regulating micro-seedling system that does not require external humidification or constant temperature equipment. This significantly improves the germination rate and seedling uniformity while reducing operational complexity and environmental costs.

[0006] To achieve the above-mentioned objectives, the present invention provides the following specific technical steps: (1) Seed pretreatment and vigor screening: In November, mature capsules of ginger plants were collected, and the bright red aril was manually removed. Seeds with plump kernels, intact seed coats, and no insect infestation or mold were selected. The seeds were placed in an 80-120 mg / L gibberellin (GA3) aqueous solution and soaked in the dark at 25°C for 12-24 hours to break the shallow dormancy and start the embryo metabolic activity. After removal, the seeds were rinsed with running water 3-5 times and then soaked in water for 5-8 days, with the water changed every 24 hours. This "hormone pulse + slow absorption and swelling" treatment can significantly improve the rate and synchronicity of the radicle breaking through the seed coat. (2) Selection and humidification of moss substrate A moss substrate with high rehydration swelling rate and intact fibrous structure after drying was selected as the germination substrate. The moss was soaked in water until it was fully swelled, then placed on gauze and gently pressed to remove excess water. The absolute moisture content of the substrate was controlled to be 7–12 times its dry weight, meaning it should not drip when squeezed in the hand, but should be fluffy and moist when released. This moisture content range ensures both a continuous liquid water film around the seeds and sufficient gas phase pores to prevent suffocation due to lack of oxygen. The moss substrate is white sphagnum moss (Sphagnum moss) Sphagnum (spp.) matrix; (3) Sowing and closed bagging Sow the pretreated seeds on the surface of the moss, 30-50 seeds per bag, ensuring that the seeds are in close contact with the moss fibers but not covered; put the sown moss substrate and seeds into a transparent, food-grade polyethylene plastic bag (0.03-0.08mm thick), seal it directly or with a tie, to form a micro-culture unit with an internal relative humidity of ≥95%. The plastic bags are made of bio-based biodegradable materials (such as polylactic acid PLA or starch-based biodegradable film) to avoid white pollution; (4) Synchronization of germination and sprouting in a variable temperature environment Place the sealed bag in a natural room temperature or a simple insulated box (such as a foam box) to carry out dark germination in a variable temperature environment within the range of 20-32℃; The variable temperature environment refers to a complete dark environment where the seed coat is exposed to a high temperature of 28-30℃ for 6-10 hours daily (this can be achieved through sunlight exposure or intermittent proximity to a heat source), and the remaining time is at 22-24℃. The seed coat is cultured in complete darkness for 12-15 days until the radicle emerges. This variable temperature mode simulates the natural diurnal temperature difference, which can maintain the average accumulated temperature and stimulate seed coat microcracks through temperature fluctuations, promoting the synchronous emergence of the radicle. If the ambient temperature is lower than the set temperature, the sealed bag can be placed on a household constant temperature pad or a warm water circulation box to achieve low-cost auxiliary heating; (5) Light environment switching and seedling hardening and transplanting When the seed radicle emerges (≥2mm in length) and some buds begin to elongate, transfer the seeds to a plastic bag containing sphagnum moss substrate and cultivate them under diffused light conditions (light intensity 2000–3000 lx, photoperiod 12h / d). Utilize the light scattering effect created by condensation on the bag walls to prevent strong light from scorching the buds and promote chlorophyll synthesis. Once the seedlings have developed their second true leaf, cut open the bag and gradually reduce humidity (hardening off for 3 days). Then, transplant the seedlings, along with the sphagnum moss substrate, into a seedling container containing peat moss:perlite = 3:1 (volume ratio). After the seedlings have recovered, manage them as usual. The moss matrix is ​​*Moss pubescens* (Golden Hair Moss). Polytrichum (spp.) matrix.

[0007] Compared with the prior art, the present invention has the following beneficial effects: (1) Matrix-container synergistic innovation: This invention is the first to combine the high capillary water-holding capacity of moss (water holding capacity can reach more than 20 times the dry weight) with the completely sealed moisture-proof structure of plastic bags to construct an independent seedling micro-ecology of "self-watering, micro-atmosphere regulation, constant humidity and temperature". Compared with perlite or filter paper, the moss matrix keeps the relative humidity of the seed layer at 92% to 98% for 15 days without the need for watering in the middle, fundamentally solving the problems of germination interruption and pathogen infection caused by frequent watering; (2) Simplified equipment dependence and lower threshold: This invention completely eliminates the need for constant temperature incubators and artificial climate chambers, and can achieve or even surpass the temperature and humidity control effects of traditional equipment using only ordinary plastic bags and moss. Comparative tests show that the germination rate of this method reaches 90.6-92.7% under variable temperature conditions, and seedlings emerge within 2.6-5 days. (3) Synergistic combination of physiological regulation: This invention combines the sequential pretreatment of "short soaking in GA3 + long soaking in clean water" with the later temperature-controlled germination, which synergistically breaks the effect of endogenous inhibitors in seeds (such as ABA), and utilizes the soaking process to regulate pre-adaptation through osmosis, so that the seed germination start time is shortened from 26 days in the control to an average of 15 days, and the radicle growth rate is increased by about 1.7 times. (4) Environmentally friendly and production-compatible: Both biodegradable plastic bags and renewable moss substrate are environmentally friendly materials, and the moss can be reused (after washing and drying). The overall operation process is simple, and a single person can process thousands of seeds per day. It is suitable for home gardening enthusiasts and can also be used for batch and standardized production in seedling companies, with strong practical transformation prospects. (5) Cross-species promotion potential: The method of this invention is applicable not only to ginger flower (Hedychium coronarium) Yellow Hedychium The seeds are effective, and experiments have shown that they are also effective against other species in the same genus (such as...). Hedychium chrysoleucum , H. coronarium and H. gardenia The technology also promotes the germination of seeds of the genus *Hedysarum* and other moisture-loving seeds, indicating that this technical framework has universal reference value in the seedling cultivation of *Hedysarum* and other moisture-loving seeds. Attached Figure Description

[0008] Figure 1 The images show the seed growth at different stages in Example 1. Figure A shows the germination state of seeds after 15 days of germination in white sphagnum moss; Figure B shows seeds that have been growing in golden sphagnum moss for 10 days; and Figure C shows seeds that have been growing in golden sphagnum moss for 15 days. Detailed Implementation

[0009] The technical solution of the present invention will be further described in detail below through embodiments, but the content of the present invention is not limited thereto. Unless otherwise specified, the methods in this embodiment are conventional methods, and the materials and reagents used are obtained from commercial sources or prepared according to conventional methods unless otherwise specified. Example 1: Seedling cultivation method of Ginger Lily 1. In November, collect mature yellow ginger flower capsules, manually remove the bright red aril, and select seeds that are plump, have intact seed coats, and are free from insect infestation and mold. Place the seeds in a 100 mg / L gibberellin (GA3) aqueous solution and soak them in the dark at 25°C for 18 hours. After removing them, rinse them 4 times with running water, and then soak them in clean water for 7 days, changing the water every 24 hours during this period. 2. Select white sphagnum moss with high rehydration expansion rate and intact fiber structure after drying as the moss substrate. Soak the moss in clean water until it is fully swollen. After taking it out, place it on gauze and press it gently to remove excess water. Control the absolute moisture content of the substrate to be 9.5 times its dry weight. 3. Sow the pretreated seeds on the surface of white sphagnum moss at a spacing of 2cm×2cm, 40 seeds per bag, and seal them in 0.05mm thick PE bags (20×30cm). Germinate the seeds in a dark environment with varying temperatures: provide 8 hours of 28℃ high-temperature pulses daily (through sunlight exposure), and maintain 22℃ for the rest of the time, and culture in complete darkness for 15 days. 4. After the radicle is ≥2mm, transfer it to a plastic bag containing golden sphagnum moss and raise it under diffused light (2500 lx, 12h / d). When the seedlings develop their second true leaf, cut open the bag and gradually reduce the humidity (harden the seedlings for 3 days). Then, transplant the whole plant, including the golden sphagnum moss, into a seedling container containing peat moss: perlite = 3:1 (volume ratio). After the seedlings have recovered, manage them as usual. Results: Germination rate was 92.7%, germination initiation time averaged 11.8 days, peak emergence occurred within 2.6 days (extremely high uniformity) (Table 1), seedlings had uniform root length and no mold. Figure 1 A), the seedlings grew well in the later stages ( Figure 1 (B, C) The root system was undamaged, and the transplant survival rate was 100%.

[0010] Example 2: Seedling cultivation method of yellow and white ginger flower seeds The method in this embodiment is the same as in embodiment 1, except that the experimental material, yellow ginger flower seeds, is replaced with yellow-white ginger flowers ( Hedychium chrysoleucum )seed.

[0011] Results: Germination rate was 91.5%, germination initiation time averaged 12.1 days, peak emergence occurred within 2.9 days (extremely high uniformity) (Table 1). Seedlings had uniform root length, almost no mold, and exhibited good growth in the later stages of seedling cultivation. Root system was undamaged, and transplant survival rate reached 100%.

[0012] Example 3: Seedling cultivation method of Ginger Lily

[0013] 1. In November, collect mature yellow ginger flower capsules, manually remove the bright red aril, and select seeds that are plump, have intact seed coats, and are free from insect infestation and mold. Place the seeds in a 100 mg / L gibberellin (GA3) aqueous solution and soak them in the dark at 25°C for 18 hours. After removing them, rinse them 4 times with running water, and then soak them in clean water for 7 days, changing the water every 24 hours during this period. 2. Select white sphagnum moss with high rehydration expansion rate and intact fiber structure after drying as the moss substrate. Soak the moss in clean water until it is fully swollen. After taking it out, place it on gauze and press it gently to remove excess water. Control the absolute moisture content of the substrate to be 9.5 times its dry weight. Pretreated seeds were sown on the surface of white sphagnum moss at a spacing of 2cm×2cm, with 40 seeds per bag. The bags were sealed in 0.05mm thick PLA bio-based biodegradable bags (20×30cm) and germinated in the dark in a variable temperature environment: 8 hours of 30℃ high-temperature pulses were given daily (through sunlight), and the rest of the time was 24℃, with complete dark culture for 13 days. 3. After the radicle is ≥2mm, transfer it to a plastic bag containing golden sphagnum moss and raise it under diffused light (2500 lx, 12h / d). When the seedlings develop their second true leaf, cut open the bag and gradually reduce the humidity (harden the seedlings for 3 days). Then, transplant the whole plant, including the golden sphagnum moss, into a seedling container containing peat moss: perlite = 3:1 (volume ratio). After the seedlings have recovered, manage them as usual. Results: Germination rate was 90.6%, germination initiation averaged 12.2 days, and seedling emergence was concentrated within 5 days (Table 1). The transplanting bags began to soften and decompose at transplanting time, with no root damage, and a 100% transplant survival rate.

[0014] Comparative Example 1 The method of this comparative example is the same as that of Example 1, except that white sphagnum moss and golden sphagnum moss are replaced with double-layer medium-speed qualitative filter paper (for conventional germination). Comparative results: Filter paper held only 3-4 times its dry weight in water. Although the humidity inside the bag was high, the moisture distribution was extremely uneven. The liquid water film around the seeds was discontinuous, and due to the lack of the fibrous porous structure of moss, condensed water flowed back into the bag, causing localized water accumulation. The germination rate was only 68.3%, and the mold rate was as high as 18% (infection after seed coat rupture in waterlogged areas). Germination initiation was delayed until day 16, and the emergence span was as long as 7 days (Table 1). This demonstrates that the high water holding capacity and aeroporous structure of moss are the key foundation for maintaining a "constantly moist but not waterlogged" microecological environment.

[0015] Comparative Example 2 The method of this comparative example is the same as that of Example 1, except that the GA3 concentration is increased to 300 mg / L, the soaking time is extended to 24 h, and the subsequent water soaking is shortened to 1 day (24 h), thus shortening the total pretreatment time. Comparative results: High-concentration, long-duration GA3 pulses induced mild toxicity in the embryo (yellowing and curling of the radicle tip), while insufficient water absorption time prevented the seed coat from softening sufficiently. The combined effect of these two factors resulted in excessive mechanical resistance when the radicle broke through the seed coat, leading to asynchronous germination. The germination rate plummeted to 55.4%, the average initiation time prolonged to 21 days, and the root tip deformity rate reached 30% (Table 1). This demonstrates that the sequence and timing of "short-duration high-osmotic GA3 signal initiation" and "long-duration low-osmotic osmotic regulation adaptation" have an irreplaceable physiological synergy.

[0016] Comparative Example 3: Incubation at a constant temperature of 25℃ throughout the entire process The method of this comparative example is the same as that of Example 1, except that the variable temperature environment in step 3 is replaced with dark culture at a constant temperature of 25°C throughout the process. Comparative Results: Without the "thermal stimulation" of temperature fluctuations, the seed coat micro-crack (expansion and contraction) effect essentially disappeared, and the degradation rate of endogenous ABA (abscisic acid) slowed down. Although the final germination rate reached 81.6% (still higher than the conventional filter paper method, thanks to moss and bags), the germination initiation time was as long as 19 days, with the peak emergence period scattered over 6 days, and uniformity decreased by 62% compared to Example 1 (Table 1). This indicates that the temperature-changing pulse is not simply "heat preservation," but a key trigger that breaks the seed coat constraint and synchronizes radicle emergence through physical stress synergistically.

[0017] Table 1. Summary of Overall Comparison of Yellow Ginger Flower Seed Germination

[0018] in conclusion This invention is not a simple aggregation of steps: the moss substrate provides physical water retention support, GA3+ slow absorption and swelling provides physiological initiation energy, the sealed bag provides a constant humidity and controlled atmosphere environment, and the variable temperature pulse provides a physical synchronization signal for shell breaking. Omission, substitution, or parameter deviation of any step (as in Comparative Examples 1-3) will lead to a sharp decrease in germination rate, a collapse in uniformity, or a surge in disease incidence. Only through the synergy of these four elements can the excellent seedling cultivation effect of "rapid, high survival rate, uniformity, and low consumption" be achieved, fully demonstrating the rigor and scientific originality of the technical solution of this invention.

[0019] The above description is merely a preferred embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for raising seedlings of the genus *Hedychium*, characterized in that, Includes the following steps: (1) After removing the aril, the seeds of the genus Gingerflower were soaked in gibberellin solution, rinsed with water, and then soaked in water continuously. (2) Lay out the moss substrate that has absorbed water to its saturation point and is not dripping water for later use; (3) Sow the pretreated seeds from step (1) onto the surface of the moss substrate and seal them in a transparent plastic bag; (4) Place the sealed bag in a variable temperature environment of 20-32℃ for dark germination; (5) After the seed radicle emerges, transfer it to a plastic bag containing moss substrate and raise seedlings under natural light. After the true leaves grow, harden off the seedlings and transplant them.

2. The method for raising seedlings of the *Hedychium* genus according to claim 1, characterized in that, In step (1), the gibberellin concentration is 80-120 mg / L, the soaking time is 12-24 h, the soaking time in clean water is 5-8 days, and the clean water is changed every 24 h.

3. The method for raising seedlings of the *Hedychium* genus according to claim 1, characterized in that, In step (2), the moss substrate is white sphagnum moss substrate, and its water content is controlled at 7 to 12 times the dry weight of the substrate.

4. The method for raising seedlings of the *Hedychium* genus according to claim 1, characterized in that, In step (3), the transparent plastic bag is made of biodegradable material and has a thickness of 0.03 to 0.08 mm.

5. The method for raising seedlings of the *Hedychium* genus according to claim 1, characterized in that, In step (4), the temperature change environment is a completely dark environment, with a high temperature of 28-30℃ for 6-10 hours per day, and the rest of the time is treated at 22-24℃ until the radicle is exposed.

6. The method for raising seedlings of the *Hedychium* genus according to claim 1, characterized in that, In step (5), the moss substrate is golden moss substrate, which is buried together with the moss substrate in the cultivation substrate during transplanting.

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