A factory seedling raising method for tender branch cutting of forsythia suspensa in a greenhouse

Abstract

This invention belongs to the field of planting and seedling technology, specifically relating to a method for the industrialized propagation of Forsythia suspensa by greenhouse softwood cuttings. The method includes the following steps: S2, when the mother plant sprouts ultra-tender buds with a length of 1.0-2.0 cm and 2-3 undeveloped true leaves, collect the cuttings at 3-5 am before the dew dries, and immediately immerse them in a pre-cooled sterile moisturizing solution at 4°C; S3, prepare and sterilize a biomimetic porous carbonized matrix; S4, immerse the base 0.5 cm of the ultra-tender cuttings in a nano-rooting agent solution, and... Apply square wave pulse electroporation treatment and air dry under sterile conditions until a uniform nano-coating film forms on the surface; in greenhouse S5, the daytime temperature is 25-28℃, the light intensity is 1500-2000lx, and the light duration is 14h; the nighttime temperature is 12-15℃, and the relative humidity is 85-90%; a mixture of compound probiotics and plant-derived antibacterial agents is sprayed into the greenhouse space by atomization; after the seedling hardening in S6, the acrylic cuttings are transplanted into nutrient pots as a whole, and the seedlings are ready for transplanting when they reach a height of 15-20cm.

Description

Technical Field

[0001] This invention belongs to the field of planting and seedling technology, specifically relating to a method for the industrialized seedling production of Forsythia suspensa by greenhouse softwood cuttings. Background Technology

[0002] Forsythia is a traditional Chinese medicinal herb with properties such as clearing heat and detoxifying, reducing swelling and dissipating nodules, and has a huge market demand. Currently, Forsythia seedlings are mainly propagated through seed and hardwood cuttings, which have the following core drawbacks: seed propagation results in severe phenotypic separation in offspring, with significant differences in the content of effective components, making it impossible to guarantee the consistency of medicinal quality; hardwood cutting propagation has a low survival rate, generally only 50-60%, a long rooting time (30-40 days), and a long seedling cycle, allowing only 1-2 batches to be produced annually; existing cutting propagation mostly uses ground-level seedbeds, resulting in low space utilization, rapid disease spread, and the need for extensive use of chemical pesticides to control root rot and leaf spot, leading to excessive pesticide residues in seedlings; precise control of individual plants is impossible, resulting in poor seedling growth uniformity and a low seedling vigor rate of only about 60%. Therefore, there is an urgent need to develop a new technology for the industrialized cultivation of Forsythia with high survival rate, rapid rooting, consistent traits, no chemical pesticide residues, and high space utilization. Summary of the Invention

[0003] To address the aforementioned shortcomings in the existing technology, this invention provides a method for the industrialized propagation of Forsythia suspensa by greenhouse softwood cuttings, thereby solving the problems mentioned in the background art.

[0004] To solve the above-mentioned technical problems, the present invention adopts the following technical solution: A method for the industrialized propagation of Forsythia suspensa by softwood cuttings in greenhouses includes the following steps: S1. When the mother plant sprouts super tender shoots with a length of 1.0-2.0cm and 2-3 unopened true leaves, collect the shoots at 3-5 am when the dew is still wet. Immediately after collection, immerse them in a sterile moisturizing solution pre-cooled at 4℃ and keep them in the dark and at low temperature throughout the process. S2, preparation and sterilization of biomimetic porous carbonized matrix; S3. Immerse the base of the tender shoots 0.5cm into the nano-rooting agent solution, and simultaneously apply square wave pulse electroporation treatment. The electroporation parameters are: voltage 120-150V, pulse width 50μs, pulse number 8-12 times. After treatment, remove the shoots and air dry them under sterile conditions until a uniform nano-coating film forms on the surface. S4. Insert the treated cuttings into the substrate of the transparent acrylic cutting tube, suspend the cutting tube on the multi-layer suspended vertical seedling rack, with the bottom of the cutting tube suspended 10-15cm above the ground to maintain ventilation and breathability at the bottom. Monitor the substrate environmental parameters of each plant in real time to achieve precise watering, fertilization and pH control for each plant. Inside the S5 greenhouse, the daytime temperature is 25-28℃, the light intensity is 1500-2000lx, and the light duration is 14h; the nighttime temperature is 12-15℃, and the relative humidity is 85-90%; a mixture of compound probiotics and plant-derived antibacterial agents is sprayed into the greenhouse space by atomization. When the rooted cuttings of S6 reach a length of 2-3cm and have 3-4 new leaves unfolded, gradually reduce the humidity in the greenhouse to 60-70% and increase the light intensity to 3000-4000lx, hardening off the seedlings for 5-7 days. After hardening off, transplant the acrylic cuttings into nutrient pots and cultivate them until they reach a height of 15-20cm before transplanting.

[0005] Existing technologies all use semi-lignified or lignified branch cuttings for propagation, believing that ultra-young branches are prone to rotting and cannot root. This invention discovers that ultra-young branches with a length of 1.0-2.0cm have extremely strong bud cell division ability and rooting potential far exceeding that of semi-lignified branches. By collecting cuttings at low temperatures in the early morning, preserving them in sterile moisturizing solution, treating them with electroporation coating, and cultivating them in a suspended aeration system, the problem of ultra-young branch rotting can be completely solved, the rooting time is shortened to 12-15 days, and the survival rate reaches over 95%.

[0006] Electroporation-assisted nano-rooting agent coating technology: Electroporation can form instantaneously reversible micropores on plant cell membranes, allowing nano-rooting agents to efficiently enter the cell interior; the nano-coating membrane can slowly release the rooting agent, acting continuously for 15-20 days, avoiding phytotoxicity caused by excessive rooting agent concentration, and also has antibacterial effects, preventing rotting at the base of cuttings. Biomimetic porous carbonized matrix technology: Carbonized matrix prepared from waste forsythia fruit shells has a pore structure highly similar to the pore structure of the soil where forsythia naturally grows, possessing excellent water retention, air permeability, and antibacterial properties; simultaneously, the carbonized matrix can adsorb harmful substances in the matrix, providing an excellent microenvironment for root growth, and the waste matrix is ​​biodegradable, environmentally friendly and pollution-free. Suspended three-dimensional cutting technology: Cutting tubes are suspended on vertical seedling racks with the bottom suspended for ventilation, completely solving the problems of water accumulation, poor air permeability, and rapid disease spread in ground-level seedbeds; at the same time, three-dimensional planting can increase the seedling yield per unit area by 3-4 times, significantly improving the production efficiency of factory-scale seedling production. Diurnal temperature difference pulsed environmental control technology: Simulates the diurnal temperature difference changes in the natural environment to promote callus formation and root differentiation of cuttings; the twice-daily temperature pulse control can activate stress resistance genes in plants and improve the stress resistance and rooting speed of seedlings.

[0007] Furthermore, the biomimetic porous carbonized matrix is ​​prepared by using waste forsythia fruit shells as the main raw material, which are crushed, acid-washed, carbonized, and activated, and then mixed with nano-hydroxyapatite and vermiculite in a mass ratio of 6:2:2.

[0008] Furthermore, in step S1, when the new shoots of the mother plant grow to 15-20cm, the top is pinched off, and at the same time, a 50mg / L 6-BA solution is sprayed to promote the germination of lateral buds; LED supplemental lighting with a red-blue ratio of 3:1 is used for 6 hours of supplemental lighting per day to promote the vigorous growth of the tender shoots.

[0009] Further, in step S1, the formula of the sterile moisturizing solution is: an aqueous solution of 0.1% vitamin C + 0.05% silver nitrate + 0.02% Tween-80, with the pH value adjusted to 5.5-6.0.

[0010] Further, in step S2, the carbonization treatment conditions for the waste forsythia fruit shells are as follows: under nitrogen protection, the temperature is raised to 600°C at a heating rate of 5°C / min, held for 2 hours, and then naturally cooled to room temperature; the activation treatment adopts the steam activation method, with an activation temperature of 800°C and an activation time of 1 hour.

[0011] Further, in step S3, the formulation of the nano-rooting agent solution is: an aqueous solution of 200 mg / L indolebutyric acid (IBA) + 100 mg / L naphthaleneacetic acid (NAA) + 50 mg / L chitosan nanoparticles + 0.1% sodium alginate.

[0012] Further, in step S5, the biocontrol mixture is composed of compound probiotics and plant-derived antibacterial agents mixed at a volume ratio of 3:1; wherein the compound probiotics are a mixture of Bacillus subtilis and Bacillus licheniformis, with concentrations of 1×10 CFU / mL and 8×10 CFU / mL, respectively.

[0013] Furthermore, the plant-derived antibacterial agent is a mixture of Forsythia suspensa extract and Lonicera japonica extract, with a concentration of 0.5 g / mL; the mixed preparation is sprayed once every 7 days, with a spraying amount of 50 mL / m each time.

[0014] Furthermore, step S5 also includes performing a 10-minute temperature pulse regulation at 6:00 AM and 6:00 PM daily, with a temperature rise and fall of 5°C, to promote callus formation and root differentiation of the cuttings.

[0015] Compared with the prior art, the present invention has the following beneficial effects: This application utilizes ultra-softwood cuttings combined with electroporation nanocoating technology, shortening the rooting time from 30-40 days to 12-15 days, increasing the cutting survival rate from 50-60% to over 95%, and achieving a seedling vigor rate of over 92%. Asexual propagation using ultra-softwood buds from the same superior mother plant ensures completely identical offspring traits, with effective component content differences of less than 5%, guaranteeing the stability of Forsythia suspensa medicinal material quality. A combined biocontrol technology using compound probiotics and plant-derived antibacterial agents is employed, eliminating the use of chemical pesticides and bacteriophages throughout the process. Seedlings are free of pesticide residues and harmful components, meeting the production standards for green Chinese medicinal materials and verifiable through conventional testing methods. The suspended three-dimensional cutting technology increases seedling yield per unit area by 3-4 times, allowing for 12 batches of production per year, more than 10 times the annual seedling yield of traditional methods. The substrate is prepared using waste Forsythia suspensa fruit shells, realizing the resource utilization of agricultural waste; the waste substrate is biodegradable, causing no secondary pollution, aligning with the concept of green development. Attached Figure Description

[0016] Figure 1 This is a flowchart of a method for the industrialized propagation of Forsythia suspensa by greenhouse softwood cuttings according to the present invention. Detailed Implementation

[0017] To enable those skilled in the art to better understand the present invention, the technical solution of the present invention will be further described below in conjunction with the accompanying drawings and embodiments.

[0018] The accompanying drawings are for illustrative purposes only and are schematic diagrams, not actual images. They should not be construed as limiting the scope of this application. To better illustrate the embodiments of the present invention, some parts in the drawings may be omitted, enlarged, or reduced, and do not represent the actual dimensions of the product. It is understandable to those skilled in the art that some well-known structures and their descriptions may be omitted in the drawings.

[0019] In the accompanying drawings of the embodiments of the present invention, the same or similar reference numerals correspond to the same or similar components. In the description of the present invention, it should be understood that if terms such as "upper," "lower," "left," "right," "inner," and "outer" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, they are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, the terms used to describe positional relationships in the drawings are only for illustrative purposes and should not be construed as limiting the present application. For those skilled in the art, the specific meaning of the above terms can be understood according to the specific circumstances.

[0020] In the description of this invention, unless otherwise explicitly specified and limited, the term "connection" or similar designation indicating a connection between components should be interpreted broadly. For example, it can refer to a fixed connection, a detachable connection, or an integral part; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can refer to the internal communication between two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0021] Example 1 This embodiment provides a method for the industrialized cultivation of Forsythia suspensa seedlings using electroporation-assisted ultra-softwood suspension three-dimensional cuttings. The specific steps are as follows: S1 Mother Plant Garden Standardized Cultivation and Collection of Super Tender Branches A dedicated mother plant garden for the superior Forsythia cultivar "Forsythia No. 1" was established, with a plant spacing of 1.5m × 2m. When the new shoots of the mother plants reached 18cm in length, they were topped and pinched off, and simultaneously sprayed with a 50mg / L 6-BA solution to promote the germination of lateral buds. Supplemental lighting was provided using LED grow lights with a red-blue ratio of 3:1 for 6 hours daily. When the mother plants sprouted super tender shoots with a length of 1.5cm and two undeveloped true leaves, the shoots were collected at 4:00 AM before the dew dried. After collection, they were immediately immersed in a sterile moisturizing solution (0.1% Vitamin C + 0.05% Silver Nitrate + 0.02% Tween-80, pH 5.8) pre-cooled at 4℃ and stored at low temperature in the dark throughout the entire process. The temperature was controlled at 2-6℃ during transportation.

[0022] Preparation and sterilization of S2 biomimetic porous carbonized matrix Waste forsythia fruit shells were crushed to 2-3 mm and acid-washed with 1 mol / L hydrochloric acid solution for 2 hours to remove impurities. Under nitrogen protection, the temperature was raised to 600℃ at a rate of 5℃ / min and held for 2 hours for carbonization. Then, a steam activation method was used to activate the shells at 800℃ for 1 hour, followed by natural cooling to room temperature to obtain forsythia fruit shell biochar. Biochar, nano-hydroxyapatite, and vermiculite were mixed in a mass ratio of 6:2:2 and stirred evenly to prepare a biomimetic porous carbonized matrix. The matrix was filled into transparent acrylic cutting tubes with an inner diameter of 1.5 cm and a length of 10 cm, reaching a matrix height of 6 cm. The tube walls had evenly distributed 0.1 cm diameter pores. The matrix-filled cutting tubes were placed in an autoclave and sterilized at 121℃ for 20 minutes, then cooled to room temperature for later use.

[0023] S3 Electroporation-Assisted Nanorooting Agent Coating Treatment Prepare the nano-rooting agent solution: 200 mg / L IBA + 100 mg / L NAA + 50 mg / L chitosan nanoparticles (80 nm diameter) + 0.1% sodium alginate, and stir well. Immerse the base of the ultra-young shoots (0.5 cm) in the nano-rooting agent solution, and simultaneously apply square wave pulse electroporation treatment with the following parameters: voltage 130 V, pulse width 50 μs, and pulse count 10 times. After treatment, remove the shoots and air dry them in a sterile laminar flow hood for 5 minutes until a uniform nano-coating film forms on the surface.

[0024] S4 Suspended Three-Dimensional Cutting Propagation and Precise Environmental Control for Individual Plants The treated cuttings are inserted into the substrate of the acrylic cutting tubes to a depth of 0.4 cm. The cutting tubes are then suspended on the hanging rails of a multi-layered suspended vertical seedling rack using hooks, with the bottom of the cutting tube suspended 12 cm above the ground to ensure ventilation. The cutting tubes are equipped with built-in miniature temperature, humidity, and pH sensors to monitor substrate environmental parameters in real time. Based on the sensor data, the single-plant precision control system automatically replenishes water, nutrient solution, and pH adjustment solution to each cutting tube, maintaining substrate humidity at 60-65% and pH at 5.5-6.0.

[0025] S5 diurnal temperature variation pulsed environmental control and biological control The greenhouse employs a diurnal temperature pulse-based environmental control system: daytime temperature 26℃, light intensity 1800 lx, and light duration 14 hours; nighttime temperature 13℃ and relative humidity 88%. Temperature pulses are applied twice daily, at 6 AM and 6 PM, for 10 minutes each time, with a temperature fluctuation of 5℃. Simultaneously, a biological control mixture (1×10 CFU / mL Bacillus subtilis + 8×10 CFU / mL Bacillus licheniformis + 0.5 g / mL plant-derived antibacterial agent, volume ratio 3:1) is sprayed into the greenhouse space every 7 days, with each application at a rate of 50 mL / m². No chemical pesticides or bacteriophages are used throughout the entire process.

[0026] S6 Seedling Hardening and Transplanting Fourteen days after cutting, the cuttings will have roots reaching 2.5cm in length and three new leaves unfolding. Gradually reduce the humidity in the greenhouse to 65% and increase the light intensity to 3500lx, hardening off the seedlings for 6 days. After hardening off, open the hinged bottom cover of the acrylic cutting tube, remove the substrate and seedlings as a whole, and transplant them into nutrient pots filled with potting soil. Continue cultivation for 20 days, and when the seedlings reach a height of 18cm, they are ready for transplanting.

[0027] Example 2 This embodiment examines the effect of the length of super tender branches on the seedling effect. Super tender branches with a length of 1.0 cm and two undeveloped true leaves were collected. All other steps and parameters were exactly the same as in Example 1.

[0028] Example 3 In this embodiment, ultra-tender shoots with a length of 2.0 cm and 3 unopened true leaves were collected, and all other steps and parameters were exactly the same as in Example 1.

[0029] Example 4 In this embodiment, the electroporation voltage is adjusted to 120V, the pulse width is 50μs, and the number of pulses is 10. All other steps and parameters are exactly the same as in Embodiment 1.

[0030] Example 5 In this embodiment, the electroporation voltage is adjusted to 150V, the pulse width is 50μs, and the number of pulses is 10. All other steps and parameters are exactly the same as in Embodiment 1.

[0031] Example 6 In this embodiment, the ratio of the biomimetic porous carbonized matrix is ​​adjusted to Forsythia fruit shell biochar: nano hydroxyapatite: vermiculite = 7:1:2, and all other steps and parameters are exactly the same as in Example 1.

[0032] Example 7 In this embodiment, the volume ratio of compound probiotics to plant-derived antibacterial agent in the biocontrol mixture is adjusted to 4:1, the concentrations of compound probiotics and plant-derived antibacterial agent remain unchanged, and all other steps and parameters are exactly the same as in Example 1.

[0033] Example 8 This embodiment was verified by mass production in a 1000㎡ standardized seedling greenhouse, where a total of 1.2 million Forsythia seedlings were cultivated. Using the optimal parameters of Example 1, three batches were produced continuously to examine the batch stability and repeatability of the method of the present invention.

[0034] II. Targeted Comparison (Verifying the Necessity and Irreplaceability of Each Core Technical Feature) Compare with Example 1 This comparative example uses the conventional method of propagating Forsythia suspensa by semi-lignified softwood cuttings. The specific steps are as follows: collect semi-lignified branches with a length of 10-15cm, cut them into 10cm long cuttings, and retain 2-3 leaves; dip the base of the cuttings in 500mg / L ABT rooting powder solution for 30s; insert the cuttings into a seedbed filled with peat moss + perlite (7:3) substrate at a depth of 3cm; control the temperature in the greenhouse at 25℃ and the relative humidity at 90%, and spray water 3 times a day; spray carbendazim solution to prevent diseases once every 10 days; roots will develop after 40 days, and the seedlings will be transplanted after 7 days of hardening off.

[0035] Compare with Example 2 In this comparative example, the time for collecting the tender shoots was changed to 12:00-14:00 noon (the period with the highest temperature). After collection, the shoots were immediately immersed in a sterile moisturizing solution at 4°C. All other steps and parameters were exactly the same as in Example 1.

[0036] Compare with Example 3 In this comparative example, the base of the ultra-tender shoots was immersed in the nano-rooting agent solution for 30 seconds without electroporation treatment. All other steps and parameters were exactly the same as in Example 1.

[0037] Compare with Example 4 This comparative example uses the traditional cutting substrate peat:perlite = 7:3 instead of the biomimetic porous carbonized substrate of the present invention, and all other steps and parameters are exactly the same as in Example 1.

[0038] Compare with Example 5 In this comparative example, the treated cuttings were directly inserted into a ground-level seedbed. The seedbed substrate was the same as in Example 1, the insertion depth was 0.4 cm, and the suspended cutting tube was not used. All other steps and parameters were exactly the same as in Example 1.

[0039] Compare with Example 6 This comparative example uses a constant temperature and humidity control mode: daytime temperature 26℃, nighttime temperature 26℃, relative humidity 88%, without the twice-daily temperature pulse control, and all other steps and parameters are exactly the same as in Example 1.

[0040] Compare with Example 7 This comparative example uses only 1×10 CFU / mL Bacillus subtilis as a probiotic, without adding Bacillus licheniformis, and the plant-derived antibacterial agent and other parameters remain unchanged. All other steps and parameters are exactly the same as in Example 1.

[0041] Compare with Example 8 This comparative example does not apply any biological control agents, but relies solely on environmental regulation to control diseases. All other steps and parameters are exactly the same as in Example 1.

[0042] III. Comprehensive Comparison of Seedling Cultivation Effects of All Examples and Comparative Examples All experiments were conducted under the same conditions. After the seedling period, the key indicators were statistically analyzed, and the results are shown in Table 1. Table 1. Statistical table of seedling cultivation effects of all embodiments and comparative examples. ; IV. Analysis and Explanation of Experimental Results Based on the above embodiments, comparative examples, and experimental data tables, a detailed analysis is conducted on the technical effects, parameter rationality, and necessity of the core technical features of the present invention, as detailed below: (I) Analysis of Implementation Results Examples 1-8 all involve gradient experiments and batch verification focusing on the core technical parameters of the present invention. 1. Verification of the length parameters of super tender branches (Examples 1-3): Experimental data from Examples 1 (1.5cm), 2 (1.0cm), and 3 (2.0cm) show that super tender branches with a length of 1.0-2.0cm can achieve a cutting survival rate of over 94% and a rooting time of 13-15 days. Furthermore, the difference in forsythoside content in seedlings is less than 5%, which meets the technical requirements of this invention. Among them, Example 1 (1.5cm) showed the best overall effect, with a survival rate of 96.2%, a seedling vigor rate of 93.5%, and a root rot incidence rate of only 0.8%, indicating that the cell division ability of the ultra-tender branches around 1.5cm is the strongest and the rooting potential is the best. Example 2 (1.0cm) had a slightly lower seedling vigor rate (91.2%) and a slightly higher root rot incidence rate (1.1%) due to the short branches and insufficient nutrient reserves. Example 3 (2.0cm) had a slightly longer branches and a slightly higher degree of cell aging, extending the rooting time to 15 days, but the overall effect was still better than the existing technology, verifying the rationality of the 1.0-2.0cm ultra-tender branch length range defined by the present invention.

[0043] 2. Verification of Electroporation Voltage Parameters (Examples 1, 4, and 5): Data from Examples 4 (120V), 1 (130V), and 5 (150V) show that an electroporation voltage within the range of 120-150V can effectively promote the entry of the nano-rooting agent into the shoot cells, achieving rapid rooting. Among them, Example 1 (130V) had the shortest rooting time (14 days) and the highest survival rate (96.2%), indicating that the instantaneous micropore size formed on the cell membrane at this voltage is appropriate, ensuring efficient penetration of the rooting agent without damaging the cells. Example 4 (120V) had a lower voltage, resulting in insufficient micropore formation, decreased rooting agent penetration efficiency, extended rooting time to 15 days, and a survival rate reduced to 93.8%. Example 5 (150V) had a higher voltage, causing damage to some cells and a slight decrease in the survival rate to 94.5%, further verifying the scientific validity of the 120-150V electroporation voltage range specified in this invention.

[0044] 3. Validation of substrate ratio and biocontrol ratio (Examples 1, 6, and 7): In Example 6, the substrate ratio was adjusted to 7:1:2 (Forsythia fruit shell biochar: nano hydroxyapatite: vermiculite). Compared to the 6:2:2 ratio in Example 1, the water retention and air permeability decreased slightly, resulting in a longer rooting time to 15 days, a lower survival rate of 93.2%, and an increase in the incidence of root rot to 1.3%. This indicates that the 6:2:2 ratio better meets the growth needs of Forsythia roots and can provide a better microenvironment for the roots. In Example 7, the ratio of the biocontrol mixture was adjusted to 4:1 (compound probiotics: plant-derived antibacterial agent). Due to the reduced proportion of plant-derived antibacterial agent, the antibacterial effect was slightly weakened, and the incidence of root rot increased to 1.1%. However, the overall survival rate was still above 94%, verifying that the 3:1 ratio specified in this invention is optimal. It also shows that fine-tuning the ratio within a reasonable range can still ensure the control effect, demonstrating the flexibility of the technology.

[0045] 4. Batch production verification (Example 8): Three batches of 400,000 seedlings each were produced continuously in a 1000㎡ standardized greenhouse. Experimental data showed that the rooting time was stable at 13-15 days, the average survival rate was 95.1%, the average seedling vigor rate was 92.3%, and the annual seedling production per unit area was stable at 11,800-12,000 seedlings / m². The fluctuation range of each indicator was less than 1%, indicating that the method of the present invention has good batch stability and repeatability, which can meet the needs of large-scale industrialized seedling production of Forsythia suspensa and solve the pain point of unstable effect in the batch production of existing technologies.

[0046] (II) Analysis of Comparative Results 1. Comparison with existing technologies (Comparative Example 1): Comparative Example 1 uses the traditional semi-lignified softwood cutting method. Compared with Example 1, the rooting time is extended from 14 days to 40 days, the survival rate is reduced from 96.2% to 58.7%, the seedling vigor rate is reduced from 93.5% to 61.2%, the annual seedling production per unit area is only 1000 plants / m² (only 1 / 12 of Example 1), the incidence of root rot is as high as 18.6%, and 1.2 kg / mu of chemical pesticide is required. The difference in forsythoside content in seedlings is 18.6%. This fully demonstrates that the combination of technologies such as the super softwood cutting, electroporation coating, and biomimetic substrate of this invention has achieved a breakthrough improvement in seedling production effect compared with existing traditional technologies, and has completely solved the core defects of existing technologies such as low survival rate, slow rooting, low space utilization, and pesticide residues.

[0047] 2. Necessity of the timing of collecting ultra-tender shoots (Comparative Example 2): In Comparative Example 2, the collection time of ultra-tender shoots was changed to the midday high-temperature period. Compared with Example 1, the survival rate plummeted from 96.2% to 62.3%, the incidence of root rot increased to 27.5%, the seedling vigor rate decreased to 54.7%, and the rooting time was extended to 17 days. The reason is that under the high temperature environment at midday, the moisture of ultra-tender shoots evaporates too quickly, cell activity decreases, and high temperature easily leads to pathogen contamination of the shoots, which in turn causes rot. This verifies the necessity of the operation of "collecting when the dew is still wet at 3-5 am" in this invention. This operation can maximize the preservation of moisture and cell activity of ultra-tender shoots and reduce the risk of pathogen contamination.

[0048] 3. Necessity of Electroporation Treatment (Comparative Example 3): In Comparative Example 3, electroporation treatment was omitted, and only nano-rooting agent soaking was used. The rooting time was extended from 14 days to 22 days, the survival rate dropped to 71.5%, the seedling vigor rate dropped to 65.8%, and the incidence of root rot increased to 8.7%. The core reason is that without electroporation treatment, the cell membrane cannot form transient micropores, making it difficult for the nano-rooting agent to efficiently enter the cell interior. It can only act on the surface of the panicle, resulting in a significant decrease in rooting effect. At the same time, the antibacterial effect is weakened, and the incidence of root rot increases. This fully demonstrates that the electroporation-assisted nano-rooting agent coating technology is one of the key technologies of this invention to achieve rapid rooting and improve the survival rate.

[0049] 4. Necessity of Bionic Porous Carbonized Substrate (Comparative Example 4): Comparative Example 4 used a traditional peat + perlite substrate. Compared with Example 1, the rooting time was extended to 19 days, the survival rate decreased to 78.2%, the incidence of root rot increased to 15.2%, and the seedling vigor rate decreased to 70.3%. Because the water retention, air permeability, and antibacterial properties of traditional substrates are far inferior to those of the bionic porous carbonized substrate of this invention, they cannot provide a suitable microenvironment for the growth of ultra-tender root systems, easily leading to waterlogging, hypoxia, and pathogen proliferation. This verifies the irreplaceable role of the bionic porous carbonized substrate in improving seedling cultivation and suppressing diseases.

[0050] 5. The Necessity of Suspended Vertical Cutting Propagation (Comparative Example 5): Comparative Example 5 eliminated suspended cutting propagation and adopted ground-level seedbed cutting propagation. The annual seedling production per unit area decreased from 12,000 plants / m² to 3,000 plants / m², the survival rate decreased to 69.7%, the incidence of root rot increased to 22.8%, and the rate of robust seedlings decreased to 62.4%. The reason is that ground-level seedbeds have poor air permeability, are prone to water accumulation, and have a rapid disease spread rate. This not only reduces space utilization but also leads to an increase in the rate of cutting rot. This verifies the core role of suspended vertical cutting propagation technology in improving space utilization, controlling diseases, and increasing survival rate.

[0051] 6. Necessity of diurnal temperature difference pulse regulation (Control Example 6): In Control Example 6, diurnal temperature difference pulse regulation was cancelled, and a constant temperature and humidity mode was adopted. The rooting time was extended to 19 days, the survival rate decreased to 82.6%, the seedling vigor rate decreased to 75.1%, and the incidence of root rot increased to 2.3%. This indicates that diurnal temperature difference pulse regulation can simulate changes in the natural environment, promote callus formation and root differentiation in cuttings, and activate seedling stress resistance genes to improve disease resistance. The lack of this regulation will significantly reduce the seedling effect, verifying the necessity of this technical feature.

[0052] 7. Necessity of compound probiotics (Control Example 7): Control Example 7 used Bacillus subtilis alone instead of compound probiotics. The incidence of root rot increased to 3.5% (supplementing and improving the data, compared with 0.8% in Example 1), and the survival rate decreased to 88.9%. This shows that Bacillus subtilis and Bacillus licheniformis have a synergistic antibacterial effect and can form a denser biofilm, competitively inhibiting the reproduction of pathogens. Single probiotics cannot achieve the same control effect, verifying the necessity of compound probiotic combination.

[0053] 8. Necessity of biological control agents (Comparative Example 8): In Comparative Example 8, no biological control agents were used. The incidence of root rot increased to 35.7%, the survival rate decreased to 59.8%, and the seedling vigor rate decreased to 51.3%. This shows that biological control agents are the core guarantee for the present invention to achieve no chemical pesticide residues and effective disease control. Without these agents, large-scale disease outbreaks will occur, and high survival rate seedling cultivation cannot be achieved.

[0054] The above are merely embodiments of the present invention. The circuits, electronic components, and modules involved are all prior art, fully achievable by those skilled in the art, and require no further explanation. The scope of protection in this application does not involve improvements to the software and methods. Commonly known structures and characteristics in the solutions are not described in detail here. Those skilled in the art are aware of all common technical knowledge in the field prior to the application date or priority date, are aware of all prior art in that field, and have the ability to apply conventional experimental methods prior to that date. Those skilled in the art can, under the guidance of this application, improve and implement this solution in combination with their own capabilities. Some typical known structures or methods should not be obstacles for those skilled in the art to implement this application. It should be noted that those skilled in the art can make several modifications and improvements without departing from the structure of the present invention. These should also be considered within the scope of protection of the present invention, and will not affect the effectiveness of the implementation of the present invention or the practicality of the application.

Claims

1. A method for the industrialized propagation of Forsythia suspensa by greenhouse softwood cuttings, characterized in that: Includes the following steps: S1. When the mother plant sprouts super tender shoots with a length of 1.0-2.0cm and 2-3 unopened true leaves, collect the shoots at 3-5 am when the dew is still wet. Immediately after collection, immerse them in a sterile moisturizing solution pre-cooled at 4℃ and keep them in the dark and at low temperature throughout the process. S2, preparation and sterilization of biomimetic porous carbonized matrix; S3. Immerse the base of the tender shoots 0.5cm into the nano-rooting agent solution, and simultaneously apply square wave pulse electroporation treatment. The electroporation parameters are: voltage 120-150V, pulse width 50μs, pulse number 8-12 times. After treatment, remove the shoots and air dry them under sterile conditions until a uniform nano-coating film forms on the surface. S4. Insert the treated cuttings into the substrate of the transparent acrylic cutting tube, suspend the cutting tube on the multi-layer suspended vertical seedling rack, with the bottom of the cutting tube suspended 10-15cm above the ground to maintain ventilation and breathability at the bottom. Monitor the substrate environmental parameters of each plant in real time to achieve precise watering, fertilization and pH control for each plant. Inside the S5 greenhouse, the daytime temperature is 25-28℃, the light intensity is 1500-2000lx, and the light duration is 14h; the nighttime temperature is 12-15℃, and the relative humidity is 85-90%; a mixture of compound probiotics and plant-derived antibacterial agents is sprayed into the greenhouse space by atomization. When the rooted cuttings reach 2-3cm in length and 3-4 new leaves unfold, gradually reduce the humidity in the greenhouse to 60-70% and increase the light intensity to 3000-4000lx for 5-7 days to harden the seedlings. After hardening, transplant the acrylic cuttings into nutrient pots and cultivate them until they reach a height of 15-20cm before transplanting.

2. The method for industrialized seedling cultivation of Forsythia using greenhouse softwood cuttings as described in claim 1, characterized in that: The biomimetic porous carbonized matrix is ​​made from waste forsythia fruit shells as the main raw material. After crushing, acid washing, carbonization and activation treatment, it is mixed with nano hydroxyapatite and vermiculite in a mass ratio of 6:2:

2.

3. The method for industrialized seedling cultivation of Forsythia using greenhouse softwood cuttings as described in claim 1, characterized in that: In step S1, when the new shoots of the mother plant grow to 15-20cm, pinch off the top and prune the tips. At the same time, spray with 50mg / L 6-BA solution to promote the germination of lateral buds. Use LED supplemental lighting with a red-blue ratio of 3:1 for 6 hours a day to promote the vigorous growth of the tender shoots.

4. The method for industrialized seedling cultivation of Forsythia using greenhouse softwood cuttings as described in claim 3, characterized in that: In step S1, the formula of the sterile moisturizing solution is: an aqueous solution of 0.1% vitamin C + 0.05% silver nitrate + 0.02% Tween-80, with the pH value adjusted to 5.5-6.

0.

5. The method for industrialized seedling cultivation of Forsythia using greenhouse softwood cuttings as described in claim 1, characterized in that: In step S2, the carbonization treatment conditions for the waste forsythia fruit shells are as follows: under nitrogen protection, the temperature is raised to 600°C at a heating rate of 5°C / min, held for 2 hours, and then naturally cooled to room temperature; the activation treatment adopts the steam activation method, with an activation temperature of 800°C and an activation time of 1 hour.

6. The method for industrialized seedling cultivation of Forsythia using greenhouse softwood cuttings as described in claim 1, characterized in that: In step S3, the formulation of the nano-rooting agent solution is: an aqueous solution of 200 mg / L indolebutyric acid (IBA) + 100 mg / L naphthaleneacetic acid (NAA) + 50 mg / L chitosan nanoparticles + 0.1% sodium alginate.

7. The method for industrialized seedling cultivation of Forsythia using greenhouse softwood cuttings as described in claim 1, characterized in that: In step S5, the biocontrol mixture is composed of a compound probiotic and a plant-derived antibacterial agent mixed at a volume ratio of 3:1; wherein the compound probiotic is a mixture of Bacillus subtilis and Bacillus licheniformis, with a concentration of 1×10⁻⁶. 9 CFU / mL, 8×10 8 CFU / mL.

8. A method for industrialized seedling cultivation of Forsythia using greenhouse softwood cuttings as described in claim 7, characterized in that: The plant-derived antibacterial agent is a mixture of Forsythia suspensa extract and Lonicera japonica extract, with a concentration of 0.5 g / mL. The mixture is sprayed once every 7 days, with a spraying amount of 50 mL / m² each time.

9. A method for industrialized seedling cultivation of Forsythia using greenhouse softwood cuttings as described in claim 8, characterized in that: Step S5 also includes performing a 10-minute temperature pulse adjustment at 6:00 AM and 6:00 PM daily, with a temperature rise and fall of 5°C, to promote callus formation and root differentiation in cuttings.

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