Method for breaking seed dormancy and accelerating germination of polygonatum sibiricum

Abstract

The present application belongs to the technical field of seed germination, and relates to a kind of seed dormancy breaking and germination method of Rhizoma Polygonati, which comprises the following steps: after seed disinfection and activation, ultrasonic-magnetic field treatment is carried out; mixed with composite growth regulator, vacuum-normal pressure cycle treatment is carried out; then mixed with stratification matrix, variable temperature stratification treatment is carried out; then transferred into germination substrate, high humidity treatment, photoperiod germination and spraying germination nutrient solution are carried out in turn; low temperature passivation synchronization treatment is carried out in the middle of germination, and then the germination conditions are restored until the seed germination. The present application effectively breaks the dormancy of Rhizoma Polygonati seed by a series of means such as ultrasonic-magnetic field synergistic wall breaking, vacuum impregnation multi-target hormone induction, programmed variable temperature stratification, low temperature synchronization regulation and light temperature and humidity cultivation coupling germination, significantly shortens the germination period, improves the germination uniformity and seedling robustness, and is suitable for large-scale and standardized seedling raising of Rhizoma Polygonati seed.

Description

Technical Field

[0001] This invention belongs to the field of seed germination technology and relates to a method for breaking dormancy and germinating Polygonatum seeds. Background Technology

[0002] As an important medicinal plant, Polygonatum sibiricum seeds exhibit significant physiological dormancy. Under natural conditions, Polygonatum sibiricum seeds require a long period of low temperature and humidity, lasting up to two winters, to germinate naturally. This deep dormancy poses a significant challenge to artificial cultivation. Currently, the methods used in production practice to break the dormancy of Polygonatum sibiricum seeds mainly fall into the following categories: The first category is physical and mechanical treatment, such as artificially breaking the seed coat, sandpaper friction, and temperature-dependent stratification, attempting to break the mechanical constraints of the seed coat through external force; the second category is chemical treatment, such as using concentrated sulfuric acid to corrode the seed coat, or soaking in hormones such as gibberellin, attempting to break dormancy chemically; the third category is long-term low-temperature stratification, which involves mixing the seeds with moist sand and placing them in a low-temperature environment for several months to simulate the natural overwintering process. However, these traditional methods all have the following drawbacks:

[0003] (1) The treatment methods are singular and lack synergy. Most methods rely on only one or two simple physical or chemical treatments, which cannot effectively address the multiple causes of dormancy in Polygonatum seeds. The dormancy of Polygonatum seeds is caused by a combination of factors such as seed coat permeability barrier, embryo physiological after-ripening requirements, and the presence of endogenous inhibitors. A single method can often only solve one link, while being powerless against other dormancy factors, ultimately leading to unstable treatment effects and generally low germination rates.

[0004] (2) Traditional stratification processes are extremely lengthy, typically requiring 90-120 days or even longer. Furthermore, temperature and humidity control throughout the process is often rudimentary, making it difficult to accurately simulate the gradient changes required for seed physiological ripening. Many farmers rely solely on experience to perform normal or low-temperature stacking, lacking a buffer during temperature transitions, which can easily cause temperature stress damage to the embryo tissue, thus exacerbating the decline in seed viability. Simultaneously, the substrate is prone to bacterial growth during stratification, leading to a high rate of seed mold and rot.

[0005] (3) Although existing chemical hormone treatment methods can stimulate radicle germination in a short period of time, they often neglect the regulation of germination uniformity. The common situation is that the germination time of seeds treated in the same batch varies greatly. The radicles that germinate early are excessively elongated and may even age prematurely due to excessive nutrient consumption, while the radicles that germinate late fail to break through the shell for a long time, resulting in a low seedling rate and uneven seedling size.

[0006] (4) Existing methods generally lack systematic intervention in the metabolic process of seed germination. For example, conventional gibberellin soaking only stays at the level of hormone signaling and does not consider the physical barrier of seed absorption and transmission; conventional low temperature stratification relies only on the slow accumulation of endogenous enzymes and fails to introduce the synergistic mechanism of exogenous enzyme hydrolysis; conventional nutrient supply and light and temperature conditions in the germination stage are often designed separately and fail to form a multi-factor coupling of light-temperature-water-fertilizer, resulting in insufficient embryo differentiation and weak stress resistance after emergence. Summary of the Invention

[0007] To address the aforementioned problems, this invention provides a method for breaking dormancy and promoting germination of Polygonatum seeds, specifically comprising the following steps:

[0008] Step 1: Select plump, healthy, and mold-free Polygonatum seeds, mix them with disinfectant at a mass ratio of 1:(1-3), soak them at 20-25℃ for 10-20 minutes, then wash off the surface disinfectant with sterile water. Mix the sterilized seeds with activation and permeation solution at a mass ratio of 1:(2-4), shake at 10-20℃ and 100-150 rpm for 7-9 hours. This step, through the osmotic regulation effect of the activation and permeation solution, synergistically enhances the permeability of the seed coat and initiates early metabolic preparation.

[0009] Preferably, the disinfectant is a potassium permanganate aqueous solution with a mass concentration of 0.2-0.4%.

[0010] Preferably, the activating permeation solution comprises chitosan, trehalose, betaine, sorbitol and deionized water in a mass ratio of (0.8-1.2):(2-3):(1.5-2.5):(5-6):(800-1200).

[0011] Step two: Remove the activated seeds from the activation and permeation solution, air dry them naturally, and then subject them to ultrasonic-magnetic field treatment. The ultrasonic frequency is 25-35kHz, and the treatment intensity is 0.3-0.5W / cm². 2 The treatment time is 15-20 minutes. An alternating magnetic field is applied simultaneously with ultrasonic treatment, with a magnetic field strength of 0.8-1.2 mT and an alternating frequency of 40-60 Hz. During the treatment, a conductive medium solution is sprayed via atomization at a rate of 8-10 mL / kg of seeds. The cavitation effect of ultrasound and the magnetostrictive effect of the alternating magnetic field work synergistically on the seed coat fiber layer, forming uniform microcrack channels on and within the seed coat surface. Simultaneously, under the guidance of the magnetic field, the conductive medium solution promotes the penetration of calcium ions and salicylate ions along these microcracks, laying the foundation for further chemical induction.

[0012] Preferably, the ultrasonic treatment adopts an intermittent pulse mode, with ultrasonic treatment lasting 2-3 minutes followed by an interval of 1-2 minutes.

[0013] Preferably, the conductive medium solution uses water as a solvent and includes calcium chloride with a mass concentration of 0.04-0.06% and salicylic acid with a mass concentration of 0.01-0.03%.

[0014] Step 3: Mix the ultrasonic-magnetic field treated seeds with the compound growth regulator at a mass ratio of 1:(2-4), vacuum at 20-22℃ to (-0.09)-(-0.07) MPa, soak for 10-15 min, restore to normal pressure within 5-10 min, continue soaking for 15-20 min, and repeat the pressure cycle 3-5 times. Gibberellin GA3 and zeatin synergistically activate the cell division and elongation signaling pathways in the seed embryo, sodium nitroprusside, as a nitric oxide donor, promotes the degradation of endogenous abscisic acid in the seed, and brassinolide enhances the sensitivity of the hypocotyl to growth-promoting signals. The four components form a positive synergistic amplification effect, breaking through the dormant chemical inhibition barrier.

[0015] Preferably, the composite growth regulator comprises gibberellin GA3, zeatin, sodium nitroprusside, brassinolide, propylene glycol, tea saponin, Tween-20, polyethylene glycol 4000, and deionized water in a mass ratio of (0.12-0.16):(0.04-0.06):(0.025-0.035):(0.01-0.014):(18-22):(0.12-0.18):(3-4):(70-80):(400-450).

[0016] Step 4: Mix the induced seeds with the stratification substrate at a volume ratio of 1:(4-6), place the mixture in a breathable stratification container, adjust the moisture content to 60-70%, and perform variable temperature stratification treatment under dark conditions. Treat at 12-14℃ for 36-54 hours, then cool down to 2-4℃ at a rate of 0.2-0.4℃ / h and treat for 700-750 hours. Then raise the temperature to 15-18℃ at a rate of 0.4-0.6℃ / h and treat for 100-150 hours. Finally, cool down to 8-10℃ at a rate of 0.1-0.3℃ / h and maintain the treatment for 200-250 hours. During the stratification period, turn the mixture over every 2-3 days and add sterile water to maintain stable moisture content. In this step, activated carbon particles adsorb and slowly release residual active ingredients from the induction solution. Potassium humate provides carbon and potassium to promote the proliferation of beneficial microorganisms. Extracellular enzymes produced by microbial metabolism, together with endogenous enzymes in the stratification process, degrade polysaccharide barriers such as mannan in the endosperm that hinder germination. At the same time, the gradual design of the temperature change program simulates the natural seasonal transition. The slow cooling and heating in the low-temperature stage avoids damage to the embryo tissue from sudden temperature changes. The microbial enzymatic hydrolysis and temperature regulation form a time-sequential synergy.

[0017] Preferably, the stratification matrix comprises river sand (particle size 0.3-0.6 mm), vermiculite (particle size 0.1-0.2 mm), activated carbon, potassium humate and compound microbial agent, in a mass ratio of (60-70):(15-20):(10-12):(0.8-1.2):(0.3-0.5).

[0018] Most preferably, the composite microbial agent is Bacillus subtilis powder, Bacillus mucilaginosus powder and Trichoderma harzianum powder, in a mass ratio of (1-3):(1-2):(1-2).

[0019] Step 5: After stratification, remove the seeds, wash off the surface stratification substrate with sterile water, mix the seeds and germination substrate at a mass ratio of 1:(2-4), and place them on a photo-temperature coupled germination bed for germination. Under dark conditions, treat at 22-24℃ and 85-90%RH for 48-54 hours, followed by photoperiod treatment with a light intensity of 18-25 μmol / (m²). 2 The photoperiod is 8-12 hours of light and 12-16 hours of darkness. The temperature during the light period is 23-25℃ and the temperature during the darkness period is 16-18℃. The relative humidity is 80-85%. During this period, a germination-promoting nutrient solution is sprayed every 20-25 hours at a rate of 80-120 mL / kg of seeds.

[0020] Preferably, the germination substrate comprises diatomaceous earth, perlite, coconut coir, and vermiculite in a mass ratio of (40-50):(20-30):(15-20):(10-15), with a moisture content of 75-85%.

[0021] Preferably, the germination nutrient solution comprises potassium nitrate, potassium dihydrogen phosphate, magnesium sulfate, boric acid, vitamin B1, melatonin, L-glutamic acid, and deionized water, in a mass ratio of (0.8-1.2):(0.4-0.6):(0.2-0.3):(0.06-0.1):(0.025-0.040):(0.012-0.02):(0.5-0.8):(100-120).

[0022] Step Six: After 5-7 days of germination, when the seed coat begins to crack, perform a low-temperature passivation and synchronization treatment. Lower the germination environment temperature to 6-8℃ at a rate of 0.4-0.6℃ / h and maintain this temperature for 20-25 hours, keeping the environment dark and at 80-90% relative humidity. Do not apply germination nutrient solution. Then, raise the temperature to 22-24℃ at a rate of 0.2-0.4℃ / h to restore normal photoperiod and nutrient solution supply. This step, through brief low-temperature treatment, inhibits excessive elongation of the radicle in rapidly germinating individuals while promoting physiological preparation in lagging individuals, significantly improving germination uniformity. After low-temperature passivation treatment, continue germination. When the radicle length reaches 2-5mm and the plumule appears, the seedlings are considered qualified after dormancy breaking and germination, and can be directly used for sowing or transplanting.

[0023] The present invention has the following advantages:

[0024] (1) This invention couples the ultrasonic cavitation effect with the magnetostrictive effect of an alternating magnetic field to form a uniform microcrack network in the seed coat fiber layer without damaging the embryo tissue. Simultaneously, the magnetic field guides the conductive medium containing calcium ions and salicylate to penetrate directionally along the cracks, achieving real-time linkage between physical cell wall disruption and chemical conduction. This treatment significantly improves seed coat permeability, creating an ideal channel for the rapid and uniform absorption of subsequent active ingredients, greatly enhancing the conduction efficiency of hormones and nutrients, and effectively activating the overall vitality of the seed.

[0025] (2) The present invention employs a four-stage temperature change program: starting at high temperature, slowly cooling down to deep cooling, then gradually increasing the temperature again, and finally gently cooling down. Each stage involves a slow rate of temperature change, allowing the embryo cells to fully adapt to temperature fluctuations and completely avoiding physiological stress caused by sudden temperature changes. Simultaneously, activated carbon is introduced into the stratification matrix to slowly release residual regulators, and potassium humate promotes the colonization of beneficial microorganisms. The extracellular hydrolytic enzymes secreted by these microorganisms synergistically degrade the polysaccharide barrier layer in the endosperm with the seed's endogenous enzymes. This combination not only significantly shortens the total stratification time but also greatly reduces the risk of mold and rot, ensuring that the embryo remains clean and plump throughout the stratification process.

[0026] (3) To address the problem of uneven germination progress among individual seeds during conventional germination, this invention implements a brief and extremely slow-temperature passivation treatment at the critical stage of initial seed coat splitting during the mid-germination period. This treatment moderately slows down the radicle growth of faster-germinating seeds while giving time to lagging seeds, thus ensuring that the germination process of all seeds becomes more uniform. After reheating, the seeds break through the shell synchronously, with minimal differences in radicle length. Moreover, due to the accumulation of sufficient ATP and stress-resistant proteins in the cells during the low-temperature period, the hypocotyl elongates more vigorously and the root hairs develop more vigorously after recovery, resulting in uniform and robust seedlings with a significantly improved transplant survival rate.

[0027] (4) This invention employs a vacuum-restoration atmospheric pressure cyclic infiltration technology to introduce four active ingredients—gibberellin GA3, zeatin, sodium nitroprusside, and brassinolide—along with a highly efficient infiltration aid into the embryo. Gibberellin and zeatin synergistically initiate cell division, sodium nitroprusside releases nitric oxide to accelerate the degradation of endogenous abscisic acid, and brassinolide enhances the embryo's sensitivity to growth signals. These four ingredients form a positive cascade amplification effect, completely breaking the dormant chemical blockade in a very short time. Simultaneously, the protective components in the compound formula effectively maintain the osmotic balance and membrane integrity of the embryo cells, avoiding the damage easily caused by traditional high-concentration hormone immersion.

[0028] (5) This invention constructs a precise light and temperature management system during the germination stage, which includes light-shielding and high-humidity pretreatment, low-light day-night alternation, and micro-temperature difference stimulation, combined with a germination substrate with slow-release function and a special nutrient solution rich in melatonin, L-glutamic acid, and vitamin B1. This system can meet the water and air conditions and mineral nutrition required for radicle elongation, and can promote the orderly differentiation of chloroplasts in the bud through low light and day-night temperature difference, avoiding excessive growth or yellowing. Melatonin enhances the seedling's tolerance to low-light environment, and organic nitrogen sources directly participate in nitrogen metabolism, saving energy consumption. Ultimately, the buds after hatching exhibit strong roots, green buds, and strong resistance, and can be directly used for field transplanting.

[0029] (6) The steps of this invention are not isolated operations, but rather mutually conditional and progressive: activation treatment improves seed coat permeability, laying the foundation for creating gaps in the physical field; micro-crack channels double the efficiency of vacuum impregnation; hormone-activated metabolic activity provides sufficient substrate for subsequent microbial enzymatic hydrolysis and temperature-controlled ripening; the embryo after stratification is close to the germination threshold and can quickly respond to germination light and temperature signals; and low-temperature passivation cleverly utilizes the individual differences accumulated in the early stage to implement precise synchronization. The entire technical solution is interconnected and systematically solves the comprehensive problems of low efficiency, long cycle, poor uniformity, and weak seedlings in breaking the dormancy of Polygonatum seeds, providing reliable technical support for large-scale and standardized seedling cultivation. Detailed Implementation

[0030] The technical solutions in the embodiments of the invention are described clearly and completely below. 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.

[0031] Example 1

[0032] The ingredients are as follows:

[0033] Activating permeate solution: chitosan, trehalose, betaine, sorbitol and deionized water, in a mass ratio of 1:2.5:2:5.5:1000.

[0034] Conductive dielectric solution: Water is used as the solvent and the solution contains 0.05% calcium chloride and 0.02% salicylic acid by mass.

[0035] Compound growth regulator: gibberellin GA3, zeatin, sodium nitroprusside, brassinolide, propylene glycol, tea saponin, Tween-20, polyethylene glycol 4000 and deionized water, in a mass ratio of 0.14):0.05:0.03:0.012:20:0.15:3.5:75:425.

[0036] Stratification matrix: river sand (particle size 0.3-0.6 mm), vermiculite (particle size 0.1-0.2 mm), activated carbon, potassium humate and compound microbial agent, in a mass ratio of 65:18:11:1:0.4.

[0037] Compound microbial inoculant: Bacillus subtilis powder, Bacillus mucilaginosus powder and Trichoderma harzianum powder, in a mass ratio of 2:1:1.

[0038] Germination substrate: diatomaceous earth, perlite, coconut coir and vermiculite in a mass ratio of 45:25:18:12, with a moisture content of 80%.

[0039] Germination nutrient solution: potassium nitrate, potassium dihydrogen phosphate, magnesium sulfate, boric acid, vitamin B1, melatonin, L-glutamic acid and deionized water, in a mass ratio of 1:0.5:0.25:0.08:0.03:0.016:0.7:100.

[0040] The specific steps are as follows:

[0041] Step 1: Select plump, healthy, and mold-free Polygonatum seeds, mix them with a 0.3% potassium permanganate aqueous solution at a mass ratio of 1:2, soak them at 22℃ for 15 minutes, then wash off the potassium permanganate on the surface with sterile water, mix the sterilized seeds with the activation and permeation solution at a mass ratio of 1:3, and shake at 15℃ and 120 rpm for 8 hours.

[0042] Step two: Remove the seeds from the activation and permeation solution, air dry them naturally, and then subject them to ultrasonic-magnetic field treatment. The ultrasonic frequency is 30kHz, and the treatment intensity is 0.4W / cm². 2 The treatment time was 18 minutes. An alternating magnetic field with a strength of 1 mT and an alternating frequency of 50 Hz was applied during the ultrasonic treatment. The conductive medium solution was sprayed by atomization during the treatment, with a spraying amount of 9 mL / kg of seeds.

[0043] Step 3: Mix the ultrasonic-magnetic field treated seeds with the compound growth regulator at a mass ratio of 1:3, vacuum at 21°C to -0.08 MPa, soak for 12 minutes, restore to normal pressure within 8 minutes, continue soaking for 16 minutes, and repeat the pressure cycle 4 times.

[0044] Step 4: Mix the induced seeds with the stratification substrate at a volume ratio of 1:5, place the mixture in a breathable stratification container, adjust the moisture content to 65%, and perform variable temperature stratification treatment under dark conditions. Treat at 13℃ for 48 hours, then cool down to 3℃ at a rate of 0.3℃ / h and treat for 720 hours. Then heat up to 16℃ at a rate of 0.5℃ / h and treat for 120 hours. Finally, cool down to 9℃ at a rate of 0.2℃ / h and maintain the treatment for 240 hours. During the stratification period, turn the mixture over every 2-3 days and add sterile water to maintain stable moisture content.

[0045] Step 5: After stratification, remove the seeds, wash off the surface stratification substrate with sterile water, mix the seeds and germination substrate at a mass ratio of 1:3, and place them on a photo-temperature coupled germination bed for germination. Under dark conditions, treat at 23℃ and 88%RH for 60 hours, followed by photoperiod treatment with a light intensity of 22 μmol / (m²). 2 The photoperiod is 10h light / 14h dark, with a light temperature of 24℃ and a dark temperature of 17℃, and a relative humidity of 83%. Germination nutrient solution is sprayed every 24 hours, with a dosage of 100mL / kg of seeds.

[0046] Step 6: After 6 days of germination, perform low-temperature passivation and synchronization treatment. Reduce the germination environment temperature to 7℃ at a rate of 0.5℃ / h and maintain it for 24 hours. During this period, maintain light-proof conditions and 85% relative humidity. Do not spray germination nutrient solution. Then, raise the temperature to 23℃ at a rate of 0.3℃ / h to restore the normal photocycle and germination nutrient solution supply.

[0047] Experimental Example 1

[0048] Test seeds: plump, healthy, and mold-free Polygonatum seeds, collected from the same plant, with a thousand-seed weight of approximately 28.5g and an initial moisture content of 12.3%.

[0049] Main reagents and substrates: Activation and permeation solution, conductive medium solution, composite growth regulator, stratification substrate, germination substrate and germination nutrient solution were prepared according to Example 1.

[0050] Control treatments: Four control groups (CK1-4) and one experimental group (T, i.e., the method in Example 1) were set up. A completely randomized block design was used, with 300 seeds treated in each group, replicated three times, for a total of 15 plots. All treatments were carried out in the same artificial climate chamber, and temperature and humidity were recorded by an automatic control system. The experimental period started from seed disinfection and continued until the radicle length reached 2-5 mm and the plumule appeared, and various indicators were recorded.

[0051] Experimental steps:

[0052] (1) Seed pretreatment (applicable to all groups except CK1)

[0053] All treatment groups (CK2-4 and T) were first soaked in 0.3% potassium permanganate solution (mass ratio 1:2) at 22°C for 15 minutes, and then rinsed 3 times with sterile water.

[0054] (2) Specific treatment plans for each group

[0055] CK1 (blank control): After disinfection, the seeds were directly mixed with wet sand (65% moisture content) at a volume ratio of 1:5 and placed at a constant temperature of 4℃ for 120 days. During this period, the mixture was turned over and watered every 7 days.

[0056] CK2 (traditional hormone soaking): After disinfection, the seeds were soaked in a 200 mg / L gibberellin GA3 solution at room temperature for 24 hours. After being taken out, they were mixed with wet sand (same as CK1) and stratified at 4℃ for 90 days.

[0057] CK3 (Single Physical + Chemical Treatment): After disinfection, the seeds were treated only with ultrasound (30kHz, 0.4W / cm²). 2 The mixture was immersed in a composite growth regulator at ambient pressure for 4 hours (without vacuum circulation) for 18 minutes (without magnetic field), then mixed with the lamination matrix and laminated at a constant temperature of 4°C for 100 days. The remaining steps were the same as in Example 1.

[0058] CK4 (without low-temperature passivation): The process was carried out exactly according to steps one to five of Example 1, but the low-temperature passivation synchronization treatment in step six was not performed. Germination continued until germination.

[0059] T (Experimental Group of the Invention): The method of Example 1 was followed exactly.

[0060] (3) Common germination conditions

[0061] Except for CK1, all treatments were placed on a photothermal coupled germination bed during the germination stage, with a light intensity of 22 μmol / (m²). 2 •s), light period 24℃ / 10h, dark period 17℃ / 14h, relative humidity 83%, spray germination nutrient solution every 24h (CK2 and CK3 also use the same nutrient solution, 100mL / kg seeds). CK1 was directly transferred to the same light and temperature conditions after stratification but without nutrient solution.

[0062] (4) Data collection standards

[0063] Germination criteria: The radicle breaks through the seed coat and is ≥2mm in length.

[0064] Germination potential: The percentage of seeds that have germinated on the 10th day after the start of germination.

[0065] Germination rate: The cumulative germination rate at the end of the entire germination process (when no new germination occurs for 5 consecutive days).

[0066] Average germination days: ∑(number of germinated seeds × number of days for that seed to germinate) / total number of germinated seeds.

[0067] Uniformity index: standard deviation of germination time (the smaller the value, the more uniform the germination).

[0068] Seedling survival rate: Number of seedlings with radicle length reaching 5mm, unfolded plumule, green cotyledons, and no deformities / total number of seeds × 100%.

[0069] Radicle length variation coefficient: After germination, 90 germinated seeds were randomly selected from each treatment (30 seeds per replicate), and the radicle length (from seed hole to root tip) was measured with vernier calipers. The percentage of the standard deviation of the radicle length to the mean of each treatment group was calculated to evaluate the uniformity of germination in the population. The smaller the value, the more synchronous the seed germination and seedling growth.

[0070] Average radicle length: Measured by randomly selecting 30 seedlings at the end of germination.

[0071] Table 1 Data Comparison

[0072] CK1 CK2 CK3 CK4 T Germination potential (%) 18.3±2.1 35.6±3.2 42.1±2.8 61.4±3.5 88.7±2.0 Germination rate (%) 52.7±3.4 68.9±2.7 73.5±3.0 84.2±2.4 96.5±1.6 Average germination days (d) 28.4±2.1 22.1±1.8 19.6±1.5 15.3±1.2 11.8±0.9 Neatness (SD) 6.7±0.5 5.2±0.4 4.8±0.3 3.9±0.3 2.1±0.2 Seedling survival rate (%) 40.2±2.8 58.6±3.1 65.3±2.9 76.8±2.5 93.2±1.8 Average radicle length (mm) 3.1±0.4 4.7±0.6 5.2±0.5 6.8±0.6 9.3±0.7 Number of days required for layering (d) 120 90 100 68 68 Days from germination to emergence (d) 32 26 23 18 14 Total period (d) 152 116 123 86 82 Mold rate (%) 12.6±1.8 9.3±1.5 7.8±1.2 4.2±0.9 1.5±0.5

[0073] Table 2 Effect of low-temperature passivation on germination synchronicity

[0074] Earliest germination time (d) Latest germination time (d) Germination time span (d) Radicle length coefficient of variation (%) CK4 11 24 13 28.6 T 12 20 8 12.3

[0075] As shown in Tables 1-2, the germination rate of the treatment (T) of this invention is as high as 96.5%, which is significantly better than the blank control (52.7%) and the traditional hormone treatment (68.9%). The seedling survival rate (93.2%) is also far ahead, indicating that this method can not only efficiently break dormancy, but also ensure the robustness of seedlings.

[0076] This invention shortens the total stratification germination cycle from 120-150 days in the traditional method to 82 days, improving efficiency by about 40-50%, while the rot rate is only 1.5%, far lower than the 7.8-12.6% of the control group. This indicates that activated carbon adsorption, microbial antagonism and precise temperature control work together to reduce the risk of disease.

[0077] The present invention exhibits the smallest standard deviation of germination time (2.1 days) and germination span (8 days), with a radicle length coefficient of variation of only 12.3%, while CK4, which lacks low-temperature passivation, shows a larger variation (28.6%). This confirms that the low-temperature passivation synchronization treatment in step six effectively reduces the differences in germination progress among individuals, resulting in more uniform seedling size.

[0078] Ultrasonic-magnetic field coupling gap creation, vacuum circulation infiltration, variable temperature enzymatic hydrolysis and stratification, and photothermal-nutrient coupling germination are all closely coordinated to achieve high vitality, high uniformity, and short cycle production of Polygonatum sibiricum seedlings, which fully meets the requirements of large-scale seedling cultivation.

[0079] The above experimental data fully demonstrate that the method for breaking dormancy and promoting germination of Polygonatum seeds provided by this invention has made significant progress in terms of germination efficiency, cycle control and seedling quality, and is suitable for promotion and application in the medicinal plant seedling industry.

[0080] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for breaking dormancy and promoting germination of Polygonatum sibiricum seeds, characterized in that, Includes the following steps: Step 1: After disinfecting the Polygonatum seeds with disinfectant, mix them with the activation and permeation solution at a mass ratio of 1:(2-4) and shake. After taking them out, perform ultrasonic treatment and apply an alternating magnetic field. Spray a conductive medium solution at a rate of 8-10 mL / kg of seeds. Step 2: After ultrasonic-magnetic field treatment, the seeds are mixed with the compound growth regulator at a mass ratio of 1:(2-4), vacuum soaked and then restored to normal pressure, and the cycle is repeated 3-5 times. After taking them out, they are mixed with the stratification matrix at a volume ratio of 1:(4-6) and subjected to variable temperature stratification treatment under dark conditions. Step 3: After stratification, mix the seeds and germination substrate at a mass ratio of 1:(2-4), and treat under dark conditions at 22-24℃ and 85-90%RH for 48-54 hours. Then, perform photoperiodic treatment with a light intensity of 18-25 μmol / (m²). 2 •s), the photoperiod is 8-12h light / 12-16h dark, the temperature during the light period is 23-25℃ and the temperature during the dark period is 16-18℃, the relative humidity is 80-85%, and the germination nutrient solution is sprayed every 20-25h, with a dosage of 80-120mL / kg of seeds; Step 4: After 5-7 days of germination, stop spraying the germination nutrient solution. Under dark conditions, lower the germination temperature to 6-8℃ and maintain it for 20-25 hours. Then raise the temperature to 22-24℃ and restore the normal photocycle and germination nutrient solution supply until the seeds germinate.

2. The method for breaking dormancy and promoting germination of Polygonatum seeds according to claim 1, characterized in that, The activation permeate solution mentioned in step one includes chitosan, trehalose, betaine, sorbitol and deionized water, with a mass ratio of (0.8-1.2):(2-3):(1.5-2.5):(5-6):(800-1200).

3. The method for breaking dormancy and promoting germination of Polygonatum seeds according to claim 1, characterized in that, In step one, the ultrasonic frequency is 25-35kHz, and the treatment intensity is 0.3-0.5W / cm. 2 The treatment time is 15-20 minutes. An alternating magnetic field is applied during the ultrasonic treatment, with a magnetic field strength of 0.8-1.2 mT and an alternating frequency of 40-60 Hz.

4. The method for breaking dormancy and promoting germination of Polygonatum seeds according to claim 1, characterized in that, The conductive medium solution mentioned in step one uses water as a solvent and includes calcium chloride with a mass concentration of 0.04-0.06% and salicylic acid with a mass concentration of 0.01-0.03%.

5. The method for breaking dormancy and promoting germination of Polygonatum seeds according to claim 1, characterized in that, In step two, evacuate to (-0.09)-(-0.07) MPa at 20-22℃, soak for 10-15 minutes, restore to normal pressure within 5-10 minutes, and continue soaking for 15-20 minutes.

6. The method for breaking dormancy and promoting germination of Polygonatum seeds according to claim 1, characterized in that, The variable temperature lamination treatment in step two involves treating at 12-14℃ for 36-54 hours, then cooling to 2-4℃ at a rate of 0.2-0.4℃ / h for 700-750 hours, then heating to 15-18℃ at a rate of 0.4-0.6℃ / h for 100-150 hours, and finally cooling to 8-10℃ at a rate of 0.1-0.3℃ / h for 200-250 hours. During the lamination process, the substrate should be turned over every 2-3 days and sterile water should be added to maintain the moisture content of the lamination matrix at 60-70%.

7. A method for breaking dormancy and promoting germination of Polygonatum seeds according to claim 1, characterized in that, The composite growth regulator mentioned in step two includes gibberellin GA3, zeatin, sodium nitroprusside, brassinolide, propylene glycol, tea saponin, Tween-20, polyethylene glycol 4000 and deionized water, with a mass ratio of (0.12-0.16):(0.04-0.06):(0.025-0.035):(0.01-0.014):(18-22):(0.12-0.18):(3-4):(70-80):(400-450).

8. A method for breaking dormancy and promoting germination of Polygonatum seeds according to claim 1, characterized in that, The stratification matrix mentioned in step two includes river sand, vermiculite, activated carbon, potassium humate and compound microbial agent, with a mass ratio of (60-70):(15-20):(10-12):(0.8-1.2):(0.3-0.5).

9. A method for breaking dormancy and promoting germination of Polygonatum seeds according to claim 1, characterized in that, The germination substrate mentioned in step three includes diatomaceous earth, perlite, coconut coir and vermiculite in a mass ratio of (40-50):(20-30):(15-20):(10-15) and a moisture content of 75-85%.

10. A method for breaking dormancy and promoting germination of Polygonatum seeds according to claim 1, characterized in that, The germination nutrient solution mentioned in step three includes potassium nitrate, potassium dihydrogen phosphate, magnesium sulfate, boric acid, vitamin B1, melatonin, L-glutamic acid and deionized water, with a mass ratio of (0.8-1.2):(0.4-0.6):(0.2-0.3):(0.06-0.1):(0.025-0.040):(0.012-0.02):(0.5-0.8):(100-120).