A breeding method of endangered angiosperm vanillae drupifera

Abstract

The present application relates to the technical field of plant breeding, and discloses a breeding method of endangered angiosperm Alipelta, comprising the following steps: sexual reproduction treatment: treating Alipelta seeds to obtain a group of Alipelta seedlings, wherein the treatment comprises soaking the Alipelta seeds in a gibberellin solution with a concentration of 150-250 mg / L for 36-60 hours; single plant screening: screening an excellent single plant with preset excellent traits from the group of Alipelta seedlings; cutting propagation treatment: treating the excellent single plant to realize amplification. Through the sexual reproduction treatment step of combining stratification treatment with soaking in a gibberellin solution with a specific parameter range, the deep dormancy problem of the Alipelta seeds is solved, and the dormancy state of the Alipelta seeds is effectively released, so that a high seed germination rate is obtained.

Description

Technical Field

[0001] This invention relates to the field of plant propagation technology, specifically a method for propagating the endangered angiosperm *Heliotropium indicum*. Background Technology

[0002] *Saruma henryi* is a species of plant belonging to the genus *Samma* in the family Aristolochiaceae. It is endemic to China, containing only one species. This endangered angiosperm has specific scientific value in plant systematics and evolutionary studies, and its plants also possess ornamental and medicinal value. Due to habitat destruction and its own reproductive limitations, its wild population is declining daily. Therefore, effective artificial breeding is of great significance for the protection and development of its germplasm resources.

[0003] In the field of plant propagation, sexual reproduction is fundamental to maintaining the genetic diversity of species. However, the seeds of *Heliotropium indicum* exhibit deep dormancy, resulting in an extremely low germination rate under natural conditions. Existing conventional seed treatment methods are ineffective in breaking this deep dormancy, making it impossible to obtain a sufficient number of seedlings that can represent the genetic diversity of the population. This limits subsequent germplasm resource screening and utilization.

[0004] Asexual propagation through cuttings is a common method for plant propagation, with the advantage of consistently maintaining the superior traits of the parent plant. However, in the propagation of *Aquilaria sinensis*, rooting of cuttings is quite difficult. This directly affects the survival rate and later growth performance of the cuttings, limiting the rapid expansion of superior individual plants and large-scale production. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention provides a method for propagating the endangered angiosperm *Heliotropium indicum*, which solves the problems of difficult seed germination and low rooting rate of cuttings in existing technologies.

[0006] To achieve the above objectives, the present invention provides the following technical solution: a method for propagating the endangered angiosperm *Cinnamomum camphora*, comprising the following steps:

[0007] Sexual reproduction treatment: The seeds of *Hylocereus undatus* were treated to obtain a population of *Hylocereus undatus* seedlings. The treatment included soaking the *Hylocereus undatus* seeds in a gibberellin solution with a concentration of 150-250 mg / L for 36-60 hours.

[0008] Individual plant selection: Select superior individual plants with preset excellent traits from the above-mentioned *Houttuynia cordata* seedling population;

[0009] Propagation by cuttings: The superior single plants are treated to achieve amplification, wherein the treatment includes soaking the base of the cuttings taken from the superior single plants in a GGR rooting powder solution with a concentration of 400-600 mg / L for 20-40 minutes.

[0010] According to the above technical solution, by performing warm stratification and cold stratification treatments sequentially, the natural seasonal changes necessary for seed completion of ripening are simulated. Warm stratification treatment provides a suitable temperature and humidity environment for embryo development and physiological ripening inside the seed, thereby breaking its physiological dormancy; the subsequent cold stratification treatment satisfies the low-temperature vernalization requirements necessary for the seed to break dormancy.

[0011] After stratification, the seeds are further treated with a gibberellin solution within a specific parameter range to supplement the insufficient content of gibberellin within the seed and initiate the endogenous hormones necessary for germination. Gibberellin can trigger a series of physiological and biochemical reactions within the seed, ultimately causing the radicle to break through the seed coat and complete the germination process.

[0012] Therefore, the technical solution of the present invention does not employ a single treatment method, but rather organically combines physical stratification treatment with chemical hormone treatment to specifically and in stages remove the dual dormancy mechanism that restricts the germination of *Houttuynia cordata* seeds, thereby obtaining a high seed germination rate.

[0013] Preferably, before the sexual reproduction treatment involves soaking the seeds in gibberellin solution, the seeds are subjected to warm stratification and cold stratification treatments in sequence.

[0014] Preferably, the warm lamination treatment is performed at 18-28°C for 50-70 days; the cold lamination treatment is performed at 1-8°C for 80-100 days.

[0015] Preferably, the cuttings used in the propagation process are semi-lignified stem segments, 10-18 cm in length and with at least one node, taken during the vigorous growth period of the plant.

[0016] Preferably, after soaking the cuttings in GGR rooting powder solution, the propagation treatment further includes the step of inserting the cuttings into the rooting substrate for rooting management.

[0017] Preferably, the rooting management steps include maintaining the relative humidity of the ambient air above 90% in the early stage after the cuttings are inserted to promote rooting; and gradually reducing the relative humidity of the ambient air to 70-85% after the cuttings have rooted to harden off the seedlings.

[0018] Preferably, the preferred traits preset in the single-plant screening include at least one of the following: strong plant growth vigor, strong tillering ability, or strong resistance to diseases and pests.

[0019] Preferably, both the warm lamination treatment and the cold lamination treatment are carried out in a lamination matrix with river sand or vermiculite as the main components.

[0020] Preferably, the cutting substrate is a substrate with sand or perlite as the main component.

[0021] This invention provides a method for propagating the endangered angiosperm *Heliotropium indicum*. It has the following beneficial effects:

[0022] 1. This invention addresses the deep dormancy problem of *Heliotropium indicum* seeds by employing a sexual reproduction treatment process that combines stratification with soaking in gibberellin solution with specific parameter ranges. This effectively breaks the dormancy state and results in a higher seed germination rate.

[0023] 2. This invention uses semi-lignified stem segments of specific specifications as cuttings at a specific time and treats them with GGR rooting powder solution with specific parameter ranges, which effectively induces the formation of adventitious roots in the cuttings, solving the technical problem of low rooting rate in conventional cuttings, thereby obtaining a higher rooting rate and a robust root system.

[0024] 3. This invention adds a rooting step to the cutting propagation process, which includes an initial high humidity to promote rooting and a later low humidity to harden the seedlings. This step provides a transition process for the tender roots formed after GGR treatment to adapt to the external environment, solving the technical problem of low survival rate of cuttings after rooting due to drastic environmental changes, thereby obtaining seedlings with high survival rate and high robustness. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of the method steps of the present invention. Detailed Implementation

[0026] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0027] Please see the appendix Figure 1 This invention provides a method for propagating the endangered angiosperm *Heliotropium indicum*, comprising the following steps:

[0028] Sexual reproduction treatment: The seeds of *Houttuynia cordata* were treated to obtain a seedling population. This treatment included soaking the seeds in a gibberellin solution at a concentration of 150-250 mg / L for 36-60 hours. Before soaking in the gibberellin solution, the seeds underwent both warm stratification and cold stratification treatments. Warm stratification was performed at 18-28℃ for 50-70 days; cold stratification was performed at 1-8℃ for 80-100 days. Both warm and cold stratification treatments were carried out in a stratification matrix primarily composed of river sand or vermiculite.

[0029] Individual plant selection: Select superior individual plants with preset excellent traits from the seedling population of *Houttuynia cordata*. The preset excellent traits for individual plant selection include at least one of the following: strong plant growth, strong tillering ability, or strong resistance to diseases and pests.

[0030] Propagation by cuttings: Superior individual plants are treated to increase their number. This treatment includes soaking the base of cuttings taken from superior plants in a 400-600 mg / L GGR rooting powder solution for 20-40 minutes. Cuttings are semi-lignified stem segments, 10-18 cm in length, with at least one node, taken during the plant's vigorous growth period. After soaking in the GGR rooting powder solution, the cuttings are then inserted into a rooting medium for rooting management. Rooting management involves maintaining a relative humidity above 90% initially after insertion to promote rooting; after rooting, the relative humidity is gradually reduced to 70-85% for hardening off. The rooting medium is primarily composed of sand or perlite.

[0031] Specifically, the present invention provides a method for propagating the endangered angiosperm *Cinnamomum camphora*, which includes three steps: sexual reproduction treatment, single plant selection, and cutting propagation treatment.

[0032] First, sexual reproduction was performed. Fruits of *Houttuynia cordata* were collected when ripe but not yet split open, and the seeds were obtained and washed. The seeds were mixed with moist river sand at a volume ratio of 1:3 and placed under constant temperature and dark conditions at 25℃ for 60 days of warm stratification to complete physiological after-ripening. Subsequently, the mixture was transferred to a 4℃ environment for 90 days of cold stratification. After treatment, the seeds were soaked in a 200 mg / L gibberellin solution for 48 hours.

[0033] Experimental results show that this step is necessary to break seed dormancy. In a comparative experiment, the seed germination rate was only 12.1% when treated with an equal amount of water instead of gibberellin solution; however, the germination rate reached 83.7% after treatment with the gibberellin solution described in this method. Further experimental data confirmed that when the gibberellin solution concentration and soaking time varied within the range of 150-250 mg / L and 36-60 hours, for example, treatment with 150 mg / L for 36 hours or 250 mg / L for 60 hours, the seed germination rates still reached 76.2% and 80.5%, respectively. This indicates that combining sequential warm and cold stratification treatments with gibberellin solution treatment with specific parameters can systematically solve the dual dormancy problem of physiological after-ripening and insufficient endogenous hormones in *Heliotropium indicum* seeds, thereby obtaining a sufficient number of seedlings.

[0034] After obtaining the seedling population of *Houttuynia cordata*, individual plant selection was carried out. During the growth of the seedlings, the performance of each individual plant was continuously observed and recorded. Based on indicators such as plant growth rate, number of tillers, and presence of disease and pest symptoms, individual plants with strong growth vigor, strong tillering ability, and no disease or pests were selected as superior individual plants and marked for subsequent expansion.

[0035] Subsequently, the selected superior individual plants were propagated by cuttings. In mid-July, semi-lignified stem segments of the current year, 12 cm in length and with two complete nodes, were taken from the superior individual plants as cuttings. The base of the cuttings was immersed in a 500 mg / L GGR rooting powder solution for 30 minutes. This specific parameter treatment with the GGR rooting powder solution is key to inducing efficient adventitious root formation in the cuttings. Experimental data showed that the rooting rate of cuttings treated in this step reached 92.3%, with an average of 6.8 roots per plant and an average longest root length of 5.4 cm. In contrast, in the control group treated only with water, the rooting rate was only 21.6%, with an average of only 1.7 roots per plant and an average longest root length of only 1.3 cm.

[0036] The plant growth regulators in the GGR rooting powder solution act on the cambium cells at the base of the cuttings, inducing them to differentiate into adventitious root primordia. When the concentration and time of the GGR rooting powder solution are adjusted within the range of 400-600 mg / L and 20-40 minutes, a high rooting rate and good root development can also be obtained.

[0037] After treatment, the cuttings are inserted into a clean perlite substrate, and the relative humidity of the ambient air is maintained above 90% in the early stage of propagation. This high humidity environment can reduce the transpiration of the seedling leaves, maintain the water balance in the plant, and provide the necessary conditions for root development.

[0038] After the cuttings have rooted, gradually reduce the relative humidity of the ambient air to 70-85% to harden them off. This process allows the seedlings' root system and leaves to gradually adapt to the lower humidity environment. This complete rooting management process is crucial for ensuring the ultimate survival of the cuttings.

[0039] Experimental results confirmed that the transplant survival rate of cuttings using this rooting management procedure reached 91.4%; while in the control group lacking this specific humidity management, the transplant survival rate was only 35.7% due to physiological water loss in the seedlings. This cutting propagation treatment procedure, by combining hormone treatment with specific parameters with refined rooting environment management, solved the technical problems of difficult adventitious root induction and low survival rate after rooting, achieving efficient expansion of superior individual plants.

[0040] Example 1:

[0041] This embodiment provides a method for propagating the endangered angiosperm *Cephalotaxus fortunei*.

[0042] First, sexual reproduction was performed. Healthy, disease-free mother plants of *Houttuynia cordata* were selected. Fruits were collected when ripe but not yet split open. The pericarp and other impurities were removed to obtain the seeds, which were then rinsed with clean water to remove any empty or shriveled seeds. The treated seeds were mixed evenly with moist river sand at a volume ratio of 3:1 and placed under constant temperature and dark conditions at 25℃ for 60 days of warm stratification. After warm stratification, the mixture was transferred to a 4℃ environment for 90 days of cold stratification. A 200 mg / L gibberellin solution was prepared, and the stratified seeds were immersed in this solution for 48 hours. The treated seeds were then evenly sown in a seedling substrate composed of peat moss, perlite, and vermiculite, covered with a fine substrate layer approximately 0.5-1.0 cm thick, and cultivated in an environment with diffused light at 20-25℃ to obtain a population of *Houttuynia cordata* seedlings.

[0043] During the growth of the seedling population, the growth vigor, tillering ability and disease and pest resistance of each individual plant were continuously observed and recorded. Individual plants with fast growth rate, large number of tillers and no disease and pest symptoms were selected as superior individual plants and marked.

[0044] Then, the superior plant was propagated by cuttings. In mid-July, semi-lignified stem segments of the current year were cut from the superior plant to prepare cuttings 12 cm long with two complete nodes. A 500 mg / L GGR rooting powder solution was prepared, and the base of the cuttings (approximately 3-5 cm) was immersed in the solution for 30 minutes. The treated cuttings were then inserted into clean perlite rooting substrate. In the early stages of propagation, the relative humidity of the ambient air was maintained above 90% using an automatic misting system. After the cuttings rooted, the misting frequency was gradually reduced, lowering the relative humidity to 70-85% for hardening off. After hardening off, the healthy rooted seedlings were transplanted into potting soil.

[0045] Example 2:

[0046] This embodiment provides a method for propagating the endangered angiosperm *Cephalotaxus fortunei*. Most of the steps are the same as in Example 1, with the difference being in some processing parameters.

[0047] In the sexual reproduction treatment, the conditions for warm stratification were 18°C ​​for 50 days; the conditions for cold stratification were 8°C for 80 days; the concentration of gibberellin solution was 150 mg / L, and the soaking time was 36 hours.

[0048] In the propagation by cuttings, the length of the cuttings was prepared to be 10 cm; the concentration of the GGR rooting powder solution was 400 mg / L, and the soaking time was 20 minutes.

[0049] All other steps, including seed collection, substrate selection, screening criteria, rooting management, and transplanting, are the same as those described in Example 1.

[0050] Example 3:

[0051] This embodiment provides a method for propagating the endangered angiosperm *Cephalotaxus fortunei*. Most of the steps are the same as in Example 1, with the difference being in some processing parameters.

[0052] In the sexual reproduction treatment, the conditions for warm stratification were 28°C for 70 days; the conditions for cold stratification were 1°C for 100 days; the concentration of gibberellin solution was 250 mg / L, and the soaking time was 60 hours.

[0053] In the propagation by cuttings, the length of the cuttings was prepared to be 18 cm; the concentration of GGR rooting powder solution was 600 mg / L, and the soaking time was 40 minutes.

[0054] All other steps, including seed collection, substrate selection, screening criteria, rooting management, and transplanting, are the same as those described in Example 1.

[0055] Comparative Example 1:

[0056] Compared with Example 1, the difference is that in the sexual reproduction treatment, instead of using a gibberellin solution with a concentration of 200 mg / L, the seeds that have undergone stratification are soaked in an equal amount of water for 48 hours, while the rest of the steps are the same.

[0057] Comparative Example 2:

[0058] Compared with Example 1, the difference is that in the cutting propagation treatment, instead of using a 500 mg / L GGR rooting powder solution, the base of the cuttings is soaked in an equal amount of water for 30 minutes, while the rest of the steps are the same.

[0059] Comparative Example 3:

[0060] Compared with Example 1, the difference is that in the cutting propagation treatment, after the cuttings are inserted into the cutting substrate, they are not subjected to specific high humidity and low humidity hardening management, but are maintained under normal natural environmental humidity. The remaining steps are the same.

[0061] Test Example 1: Seed Germination Rate Test

[0062] This test was conducted to determine the effect of the treatments described in Examples 1-3 and Comparative Example 1 on the germination rate of *Heliotropium indicum* seeds.

[0063] The experimental steps are as follows:

[0064] Random samples were taken from the seed batches processed in Examples 1, 2, 3, and Comparative Example 1. Each batch was set up with three replicates, and each replicate contained 200 seeds.

[0065] Each duplicate of seeds was evenly sown in a seedling tray containing the same seedling substrate (as in Example 1) and covered with a 0.5-1.0 cm thick layer of fine substrate.

[0066] All seedling trays were placed in the same environment for cultivation, with the following environmental parameters set: temperature 20-25℃, relative humidity 75-85%, and diffused light.

[0067] From the date of sowing to day 45, the number of germinated seeds in each seedling tray was counted. The criterion for seed germination was: the radicle broke through the seed coat and reached a length of 1.0 cm.

[0068] The seed germination rate of each replicate was calculated using the following formula, and the average of the three replicates was taken as the final seed germination rate of the experimental group: Seed germination rate (%) = (number of germinated seeds / total number of seeds sown) × 100%.

[0069] The experimental results are recorded in Table 1.

[0070] experimental group Seed germination rate (%) Example 1 83.7 Example 2 76.2 Example 3 80.5

[0071] The data in Table 1 show that the seed germination rates of Examples 1-3 were all higher than those of Comparative Example 1. Comparative Example 1, which was not treated with gibberellin solution, had a seed germination rate of only 12.1%. This indicates that although the physiological after-ripening process of *Houttuynia cordata* seeds was completed after warm-cold stratification treatment, a dormancy state caused by insufficient endogenous hormones still existed. Exogenous supplementation with a specific concentration of gibberellin solution can effectively break the dormancy state, thereby improving the seed germination rate.

[0072] Examples 1-3 involved treatment with gibberellin concentrations of 150-250 mg / L and treatment times ranging from 36-60 hours, achieving seed germination rates of 83.7%, 76.2%, and 80.5%, respectively. These data demonstrate that gibberellin treatment within this parameter range consistently yields high seed germination rates. The parameter ranges in this method provide effective technical conditions for obtaining high seed germination rates.

[0073] The sexual reproduction treatment in this technical solution systematically solves the dual dormancy problem of physiological after-ripening and insufficient endogenous hormones in *Heliotropium indicum* seeds by combining sequential warm and cold stratification treatments with subsequent gibberellin solution treatment with specific parameters. This sexual reproduction treatment step ensures that a sufficient number of genetically diverse seedlings can be obtained before the subsequent screening steps, providing a foundation for the implementation of the entire breeding method.

[0074] Test Example 2: Rooting Rate and Root Quality Test of Cuttings

[0075] This test was conducted to determine the effect of the treatments described in Examples 1-3 and Comparative Example 2 on the rooting of *Cinnamomum camphora* cuttings.

[0076] The experimental steps are as follows:

[0077] Random samples were taken from the batches of scions treated in Examples 1, 2, 3, and Comparative Example 2. Each batch was set up with three replicates, and each replicate contained 50 scions.

[0078] Each batch of cuttings was inserted into a cutting tray containing the same cutting substrate (as in Example 1) and placed in the same environment for rooting management, with environmental parameters consistent with the rooting management steps in Example 1.

[0079] Thirty days after cutting, remove each group of cuttings from the substrate and wash the base with clean water.

[0080] Count the number of cuttings that produced adventitious roots in each replicate. The standard for rooting is: at least one adventitious root with a length of not less than 1.0 cm is produced at the base of the cutting.

[0081] For rooted cuttings, count the total number of adventitious roots and measure the length of the longest adventitious root.

[0082] The rooting rate of cuttings, the average number of roots per plant, and the average longest root length of each replicate were calculated using the following formulas, and the average value of the three replicates was taken as the final result of the experimental group.

[0083] Rooting rate of cuttings (%) = (Number of rooted cuttings / Total number of cuttings) × 100%.

[0084] Average number of roots per plant (cuts) = Total number of adventitious roots of all rooted cuttings in the replicate / Number of rooted cuttings in the replicate.

[0085] Average longest root length (cm) = Sum of the longest roots of all rooted cuttings in the replicate / Number of rooted cuttings in the replicate.

[0086] The experimental results are recorded in Table 2.

[0087] Table 2. Rooting test results of cuttings in each experimental group:

[0088]

[0089]

[0090] The data in Table 2 show that the rooting rate, average number of roots per plant, and average longest root length of the cuttings in Examples 1-3 were all higher than those in Comparative Example 2. Comparative Example 2, which only treated the cuttings with water, had a rooting rate of only 21.6%, and the number and length of the resulting roots were small. This indicates that treating the semi-lignified stem segments of *Aquilaria sinensis* with GGR rooting powder solution is a necessary technical condition for inducing efficient adventitious root production.

[0091] The plant growth regulators in the GGR rooting powder solution act on the cambium and parenchyma cells at the base of the cuttings, inducing cell division and differentiation, thereby forming adventitious root primordia and developing into roots. Data from Comparative Example 2 indicate that, without the application of exogenous plant growth regulators, the endogenous hormone levels of the cuttings themselves are insufficient to initiate an effective rooting process.

[0092] Examples 1-3 involved treatment with GGR rooting powder solution at concentrations of 400-600 mg / L and treatment times ranging from 20-40 minutes. The rooting rate of the cuttings all reached over 84%, and the number and length of roots showed excellent development. This indicates that the defined range of cutting propagation treatment parameters in this method provides effective technical conditions for amplifying the selected superior individual plants, ensuring that superior traits can be fixed and replicated on a large scale through asexual reproduction.

[0093] Test Example 3: Survival rate test of transplanted cuttings:

[0094] This test was conducted to determine the effect of the rooting management methods described in Examples 1-3 and Comparative Example 3 on the survival rate of *Houttuynia cordata* cuttings after transplanting.

[0095] The experimental steps are as follows:

[0096] From the cutting batches of Examples 1, 2, 3, and Comparative Example 3, seedlings of the same size and already rooted were selected. Each batch was set up with three replicates, and each replicate contained 50 rooted seedlings.

[0097] Transplant all selected seedlings into individual culture pots containing the same potting soil.

[0098] All the culture pots were placed in the same greenhouse environment for cultivation. The environmental parameters were set as follows: temperature 20-25℃, relative humidity 65-75%, and diffused light.

[0099] Thirty days after transplanting, the number of surviving plants in each replicate was counted. The criteria for plant survival were: no permanent wilting and visible new leaves growing at the top.

[0100] The transplant survival rate of each replicate was calculated using the following formula, and the average of the three replicates was taken as the final transplant survival rate of the experimental group.

[0101] Transplant survival rate (%) = (Number of surviving plants / Total number of transplanted plants) × 100%.

[0102] The experimental results are recorded in Table 3.

[0103] Table 3. Results of the transplant survival rate test for cuttings in each experimental group:

[0104] experimental group Transplant survival rate (%) Example 1 91.4 Example 2 86.8 Example 3 89.1

[0105] The data in Table 3 show that the transplant survival rate of the cuttings in Examples 1-3 was higher than that in Comparative Example 3. The cuttings in Comparative Example 3, after rooting, were placed directly under normal ambient humidity, and their transplant survival rate was only 35.7%. This indicates that specific rooting management is a necessary technical condition for obtaining a high transplant survival rate in cutting propagation.

[0106] In the early stages of rooting, the newly formed adventitious root system of cuttings has limited water absorption capacity. The rooting management steps in this example, by maintaining a relative humidity above 90% in the initial stage, reduced transpiration from the seedling leaves, maintained the plant's water balance, and provided time for further root development. In contrast, the seedlings in Comparative Example 3, lacking this high-humidity environment, experienced transpiration water loss exceeding root absorption, leading to physiological dehydration and plant death.

[0107] The later stage of the rooting management process, which involves reducing humidity to harden the seedlings, allows the roots and leaves to gradually adapt to the lower humidity environment, completing the physiological transition from the cutting substrate to the potting soil. Therefore, the seedlings in Examples 1-3 treated with this step exhibited a high survival rate after transplanting. This rooting management step solves the technical problem of low survival rates caused by environmental changes after rooting of cuttings, ensuring that the rooting effect obtained through GGR solution treatment can be translated into surviving plants.

[0108] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A method for propagating the endangered angiosperm *Cinnamomum camphora*, characterized in that, Includes the following steps: Sexual reproduction treatment: The seeds of *Hylocereus undatus* were treated to obtain a population of *Hylocereus undatus* seedlings. The treatment included soaking the *Hylocereus undatus* seeds in a gibberellin solution with a concentration of 150-250 mg / L for 36-60 hours. Individual plant selection: Select superior individual plants with preset excellent traits from the above-mentioned *Houttuynia cordata* seedling population; Propagation by cuttings: The superior individual plants are treated to achieve amplification, wherein the treatment includes soaking the base of the cuttings taken from the superior individual plants in a GGR rooting powder solution with a concentration of 400-600 mg / L for 20-40 minutes; Before soaking the seeds in gibberellin solution during the sexual reproduction treatment, the process also includes performing warm stratification and cold stratification treatments on the seeds in sequence. The warm lamination treatment is performed at 18-28℃ for 50-70 days; the cold lamination treatment is performed at 1-8℃ for 80-100 days. After soaking the cuttings in GGR rooting powder solution, the propagation treatment also includes the step of inserting the cuttings into the rooting substrate for rooting management. The rooting management steps include maintaining the relative humidity of the ambient air above 90% in the early stage after the cuttings are inserted to promote rooting; and gradually reducing the relative humidity of the ambient air to 70-85% after the cuttings have rooted to harden off the seedlings.

2. The method for propagating the endangered angiosperm *Heliotropium indicum* according to claim 1, characterized in that: The cuttings used in the propagation process are semi-lignified stem segments, 10-18 cm in length, with at least one node, taken during the vigorous growth period of the plant.

3. The method for propagating the endangered angiosperm *Heliotropium indicum* according to claim 1, characterized in that: The pre-defined desirable traits in the single-plant screening include at least one of the following: strong plant growth vigor, strong tillering ability, or strong resistance to diseases and pests.

4. The method for propagating the endangered angiosperm *Heliotropium indicum* according to claim 1, characterized in that: Both the warm and cold lamination processes are carried out in a lamination matrix with river sand or vermiculite as the main components.

5. The method for propagating the endangered angiosperm *Heliotropium indicum* according to claim 1, characterized in that: The cutting substrate is a substrate with sand or perlite as the main component.

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