Root-damage-free hard wood cutting breeding method for special extremely dangerous tree species of Guangxi province

Abstract

The invention discloses a root-damage-free hard wood cutting breeding method for a special extremely dangerous tree species of Gangxi, and relates to the technical field of plant breeding. By optimizing cutting selection and cuttage time, using a composite rooting accelerant for treatment, optimizing matrix proportion and specifications of two cups (a cuttage cup and a cultivation cup) and adopting a root-damage-free transplanting technology and a nursery stock management and protection technology, the cuttage rooting rate is remarkably increased and is larger than 80%, and the callus formation period is shortened to 75 days. According to the method, the problems of sexual propagation limitation (few seeds, recalcitrant seeds, low germination rate and the like) of the hedyotis diffusa are broken through, the door of asexual propagation (cutting propagation) is opened, the problem of low cutting rooting rate is solved, the method is suitable for large-scale propagation of the tree species, and important technical support is provided for population protection and recovery of the tree species.

Description

Technical field

[0001] The invention relates to the technical field of plant propagation, and in particular to a root-injury-free hard-branch cutting propagation method for an extremely endangered tree species endemic to Guangxi, Psoralea corymbosa. [Background Technology]

[0002] Hopea chinensis, a species of the genus Hopea in the Dipterocarpaceae family, is a first-class protected wild plant in China (critically endangered). It serves as a "living fossil" for studying the evolution of tropical flora and the northward adaptation mechanisms of the Dipterocarpaceae family, possessing significant ecological and economic value. Its durable wood is known as "millennium wood." Its byproducts include aromatic oils used in high-end cosmetics and valuable traditional Chinese medicines. Its bark extract has been shown to be effective in treating Alzheimer's disease. Strengthening its conservation and research is an urgent need for biodiversity conservation and resource development in my country. Currently, the number of remaining Hopea chinensis plants is extremely small. Native to the Shiwandashan and Daqingshan regions of Guangxi, my country, Hopea chinensis is now confined to the Shiwandashan region. Due to habitat destruction and self-reproduction, its population has plummeted. Within the next 10 years, the wild population of Hopea chinensis may reach an irreversible threshold, raising concerns about its survival. Furthermore, the limited availability of seeds, their short lifespan, easy inactivation, and low germination rate make it difficult to meet population restoration needs. Therefore, there is an urgent need to develop a cutting cultivation method suitable for S. angustifolia to expand its reproduction coefficient and accelerate the supply of seedlings, which is extremely important for the conservation and restoration of S. angustifolia populations.

[0003] The disclosure of the above background technology content is only used to assist in understanding the inventive concept and technical solution of the present invention. It does not necessarily belong to the prior art of this patent application. In the absence of clear evidence that the above content has been disclosed on the filing date of this patent application, the above background technology should not be used to evaluate the novelty and creativity of this application. [Summary of the invention]

[0004] To facilitate accurate understanding, the following are the precise definitions of the technical terms that will appear in the following text:

[0005] "IBA" refers to indolebutyric acid; "GA3" refers to gibberellin A3; "IAA" refers to indoleacetic acid; "VB 12 " refers to vitamin B12; "VC" refers to ascorbic acid; "KNO3" refers to potassium nitrate; "ABT" refers to ABT rooting powder, a composite rooting agent developed by the Chinese Academy of Forestry; "GGR" refers to green plant growth regulator, a broad-spectrum rooting promoter developed by the Chinese Academy of Agricultural Sciences.

[0006] The purpose of the present invention is to propose an efficient and stable method for propagating the narrow-leaved sedge, a critically endangered tree species endemic to Guangxi, by hard branch cuttings without damaging the roots, so as to solve the technical problems of low propagation efficiency and poor survival rate in the above-mentioned prior art.

[0007] To this end, the present invention adopts the following technical solutions:

[0008] A method for propagating the critically endangered tree species endemic to Guangxi, Angustifolia serrata, by root-injury-free hardwood cuttings, comprises the following steps:

[0009] S1. Cutting season: Cuttings should be taken between mid-December and early-mid January.

[0010] S2. Cutting Selection: Select robust, lush plants from a population with a high number of narrow-leaved sedges as mother plants. Cut woody branches with axillary buds in the lower and middle parts of the crown as cuttings.

[0011] S3 cuttings treatment: soak the base of the cuttings into a rooting promoter, the rooting promoter is adjusted to a paste with loess heart soil, and the base of the cuttings is buried in the rooting promoter paste;

[0012] S4. Cutting cup and substrate selection: Cutting cup specifications are 7-10 × 8-12 cm (diameter × height); cutting substrate is loess soil, the substrate is exposed to the sun 30 days in advance and sprayed with 0.1% carbendazim solution for disinfection, and watered thoroughly 1 hour before cutting;

[0013] S5. Cutting Method: Fill a cutting cup with cutting medium. Make a small hole in the center of the medium. Insert the treated cuttings along with the rooting promoter paste into the hole to a depth of 3-5 cm. Compact the medium at the base of the cuttings and then water them with water to establish roots.

[0014] S6. Environmental Control: After grafting, maintain the temperature at 25-28°C and the relative humidity at 85%-88%. Keep the substrate moist but not waterlogged, and mist once or twice daily.

[0015] S7. Rooting Management: 70-100 days after cutting, callus tissue begins to form at the base of the cuttings and roots will form. After rooting, gradually reduce the frequency of spraying and increase the light intensity to promote seedling growth.

[0016] S8. Transplanting and maintenance: When the rooted cuttings grow to 12-14 cm, use a transplanting and burying device to transplant them without damaging the roots. Transplant the rooted cuttings together with the yellow heart soil on the roots from the cutting cup to the cultivation cup. Fill the cultivation cup with nutrient soil matrix. Make a large hole of 15×18 cm in the center of the nutrient soil matrix. Use a transplanting and burying device to fill the dug rooted cuttings together with the yellow heart soil on the roots into the hole. After compacting, water it thoroughly. Subsequently, cultivate it to the seedling specifications suitable for wild planting and then plant it out in the nursery; from the day after transplanting to 90 days, cover the seedlings with a double layer of shade net with a shading rate of 60%-80%; 90 days after transplanting, remove one layer of shade net and keep one layer of shade net until the seedlings are transplanted; after transplanting, adjust the maintenance method of the seedlings according to the growth period of the narrow-leaved slope barrier seedlings (rapid growth period March-September, slow growth period October-November and stagnant period December-February).

[0017] Furthermore, in step S2, the length of the cuttings is controlled to be 10-12 cm; 4-6 leaves are retained to ensure that each cutting has 3 or more buds; the thickness is required to be between 0.2-0.4 cm, and the lower part is cut into a 45° bevel.

[0018] Furthermore, the rooting promoter in step S3 comprises IBA 500 mg / L, GA 3 25 mg / L, IAA 25 mg / L, VB 12 200mg / L, VC50mg / L, KNO31g / L, Sargassum fermentation extract 3g / L.

[0019] Furthermore, in the cutting treatment described in step S3, the base of the cutting is buried in the rooting promoter paste to a depth of 3.5 cm for 30 hours.

[0020] Furthermore, the cutting method described in step S5 is to make a small hole 4-6 cm deep in the center of the cutting medium of the cutting cup, insert the treated cuttings together with the rooting promoter paste into the hole to a depth of 3-5 cm, compact the medium at the base of the cuttings, and then water them to establish roots; wherein the depth of the treated cuttings inserted into the hole is 0.5-1 cm less than the depth of the hole itself. After the operation is completed, the medium is gently compacted to fill the gap.

[0021] Furthermore, the specifications of the transplanting and burying device in step S8 are 15-18×18-20 cm (caliber×height), and the specifications of the cultivation cup are 30-35×35-40 cm (caliber×height).

[0022] Furthermore, the transplanting nutrient soil matrix described in step S8 is prepared by mixing peat moss, loess heart soil, and perlite in a volume ratio of 2:2:1. The physical and chemical properties of the matrix are suitable for the growth of narrow-leaved sedge seedlings, and the matrix's air and water permeability facilitates the expansion and elongation of the narrow-leaved sedge seedlings' roots. The matrix is ​​loaded with NPK slow-release microcapsules, where the capsules contain elements C:N in a ratio of 25:1, ensuring a continuous nutrient supply for the growing cuttings.

[0023] Furthermore, the period from March to September after transplanting in step S8 is the rapid growth period of narrow-leaved slope barrier, and the corresponding maintenance method is to spray 0.1% compound fertilizer once a month, wherein the ratio of N:P:K contained in the compound fertilizer is 15:15:15, and it is used together with 0.05% chelated iron fertilizer solution to improve the chlorophyll content and growth rate of the seedlings.

[0024] Furthermore, in step S8, the slow growth period of the narrow-leaved sedge is from October to November after transplanting, and the corresponding maintenance method is to spray 0.1% potassium dihydrogen phosphate once a month to improve the cold resistance of the seedlings.

[0025] Furthermore, the 12-2 months after transplanting in step S8 is the growth stagnation period of narrow-leaved sedge, and the corresponding maintenance method is to stop fertilizing, and perform watering and maintenance according to the dryness and wetness of the substrate to maintain the moisture content of the substrate in the range of 50%-80%.

[0026] The design principles and technical principles of the technical solution of the present invention are as follows:

[0027] 1. The physiological basis for dormant cuttings: Cuttings are taken from mid-December to early-mid January to capitalize on the physiological characteristics of the winter dormancy of the narrow-leaved sedge. During this period, sap flow slows, starch content in branches reaches its peak, and soluble sugar and nitrogen reserves are abundant, providing the material basis for callus formation after cuttings. In low-temperature environments, endogenous abscisic acid (ABA) inhibits terminal bud activity, but lateral buds remain dormant. Artificial temperature control (25-28°C) accelerates ABA degradation, activates auxin (IAA) synthesis, and induces bud initiation and root differentiation.

[0028] 2. Synergistic mechanism of composite rooting promoter: The rooting promoter uses IBA, GA3, IAA, VB 12 A combination of VC, KNO3, and Sargassum fermentation extract, the auxin IBA and IAA, can activate the PIN gene family, directing polar auxin transport to the incision site, forming a local concentration peak, inducing dedifferentiation of cortical cells into callus, and promoting root primordium initiation. Gibberellic acid can upregulate EXPANSIN gene expression, reduce cell wall lignin content, promote cell elongation and vascular tissue differentiation, and advance the formation of callus vascular bundles. VB 12It participates in methyl transfer reactions and enhances cell metabolic activity. VC removes reactive oxygen species (ROS) to reduce oxidative damage. The alginate and trace elements in Sargassum extract, such as Fe and Zn, synergistically promote the increase in the number of adventitious root primordia.

[0029] 3. Principle of Coupled Temperature and Humidity Control: After grafting, maintain a temperature of 25-28°C and a relative humidity of 85%-88% to simulate a tropical monsoon climate microenvironment. This temperature and humidity range creates a suitable habitat for S. angustifolia, promoting enzyme activity within the plant, enhancing the cuttings' physiological functions and environmental adaptability, and promoting cell division and growth.

[0030] 4. Root protection principle of root-damage-free transplanting: A special seedling lifting device is used to bring out the roots intact, combined with a specific ratio of matrix: the intact root system maintains the activity of the root apical meristem, avoiding root damage and "traumatic ethylene" outbreaks caused by traditional transplanting; in the construction of the matrix system, a gradient control strategy is used to formulate a special transplanting matrix (peat soil: loess heart soil: perlite = 2:2:1, v / v) with optimized pore structure (total porosity > 65%) and nutrient slow-release properties. Its hydraulic conductivity (Ks = 12.5 cm / d) is 2.3 times higher than that of the cutting matrix, and it is loaded with NPK slow-release microcapsules (C:N = 25:1), which effectively promotes the reconstruction of the root system architecture and the recovery of absorption function after transplanting.

[0031] The technical advantages of the present invention compared with the prior art are as follows:

[0032] Advantage 1: Breaking through seasonal restrictions and significantly improving rooting rate

[0033] In the existing technology, traditional cuttings are mostly taken in spring, but the present invention found through four-season comparative tests that the rooting rate of winter cuttings reached 67.7%, a significant increase compared to spring (21.1%). Further monthly tests confirmed that the rooting rate from mid-December to mid-January was as high as 70%-76.7%, and the time for callus formation was shortened to less than 120 days. Winter cuttings are in a "low metabolism-high reserve" state, and combined with artificial temperature control to break dormancy in advance, effectively improving the rooting rate of cuttings and significantly increasing the efficiency of seedling output.

[0034] Advantage 2: The composite rooting system significantly shortens the time for callus formation and improves rooting efficiency

[0035] Conventional cuttings use only a single hormone, resulting in a low rooting rate and a long callus formation cycle. 12A composite rooting promoter composed of VC, KNO3, and fermented Sargassum extract, through the synergistic action of multiple components, shortened callus formation time to 75 days, a 44-day reduction compared to the original callus formation time of 119 days at the same time, an increase of 37.0%. The rooting rate reached 81.9%, a 2.7-fold increase compared to the single IBA treatment (22.2%). The rooting agent was mixed with loess soil to form a paste, which prolonged the attachment time of the active ingredients while providing trace mineral ions, maintaining the hormone concentration at the cutting incision at the optimal threshold, resulting in "short-term, high-survival, and strong root systems" for cuttings, laying the physiological foundation for later transplanting.

[0036] Advantage 3: Root-free transplanting technology builds a continuous growth system

[0037] Traditional transplanting uses a shovel to lift the seedlings, which has a high root damage rate, resulting in a long recovery time for the seedlings and the easy occurrence of "dead seedlings". The present invention uses a patented seedling lifting device to completely bring out the roots, and the root damage rate is less than 5%, which is significantly lower than conventional methods. Combined with a specific ratio of transplanting substrate and shading and fertilization strategies, the transplant survival rate reaches 100%, and the recovery time is shortened to 15 days, which is 69% shorter than conventional transplanting (48 days). Gradient substrate regulation and precise fertilization increase the average annual growth of transplanted seedlings by 50%, realizing a continuous development process of "transplanting and growth".

Brief Description of the Drawings

[0038] Figure 1 This is a diagram of the rooting process of cuttings according to Example 1 of the present invention;

[0039] Figure 2 1 is a diagram showing the growth state of the rooted cuttings according to Example 1 of the present invention;

[0040] Figure 3 1 is a diagram showing the growth state of the rooted cuttings according to Example 1 of the present invention;

[0041] Figure 4 1 is a diagram showing the growth state of the rooted cuttings according to Example 1 of the present invention;

[0042] Figure 5 1 is a diagram showing the growth state of the rooted cuttings according to Example 1 of the present invention;

[0043] Figure 6 Schematic diagram of the cuttings implanted into the implantation cup according to Example 1 of the present invention;

[0044] Figure 7 is a schematic diagram of transplanting rooted cuttings into a cultivation cup according to Example 1 of the present invention;

[0045] The numbers in the figure are: 1 is the cutting, 2 is the loess soil, 3 is the rooting promoter paste, 4 is the cutting cup, 5 is the rooted cutting, 6 is the nutrient soil matrix, and 7 is the cultivation cup. [Specific implementation method]

[0046] The present invention will be further described in detail below with reference to specific embodiments and accompanying drawings. It should be emphasized that the following description is merely illustrative and is not intended to limit the scope and application of the present invention. The terms "include," "comprising," "having," "containing," and the like used herein are open-ended terms, meaning including but not limited to.

[0047] In a specific embodiment of the present invention, the following method is used for cutting propagation of Scutellaria baicalensis:

[0048] A method for propagating the critically endangered tree species endemic to Guangxi, Angustifolia serrata, by root-injury-free hardwood cuttings, comprises the following steps:

[0049] S1. Cutting season: Cuttings should be taken between mid-December and early-mid January.

[0050] S2. Cutting selection: Select strong and lush plants from a population with a large number of narrow-leaved sedges as mother plants, and cut lignified branches with axillary buds in the middle and lower parts of the crown as cuttings 1; the length of the cuttings 1 is controlled to be 10-12 cm; retain 4-6 leaves and ensure that each cutting 1 has 3 or more buds; the thickness requirement is between 0.2-0.4 cm, and the lower part is cut into a 45° bevel.

[0051] S3. Cuttings treatment: The base of the cuttings 1 is immersed in a rooting promoter, the rooting promoter components include IBA500mg / L, GA325mg / L, IAA25mg / L, VB 12 200mg / L, VC50mg / L, KNO31g / L, Sargassum fermentation extract 3g / L; the rooting promoter is mixed with loess soil 2 to form a paste, and the base of the cutting 1 is buried in the rooting promoter paste 3 to a depth of 3.5cm for 30 hours;

[0052] S4. Cutting cup and substrate selection: Cutting cup 4 specifications are 7-10 × 8-12cm (diameter × height); cutting substrate is loess heart soil 2, the substrate is exposed 30 days in advance and sprayed with 0.1% carbendazim solution for disinfection, 1 hour before cutting, soaked in water;

[0053] S5. Cutting Method: Make a small hole 4-6 cm deep in the center of the cutting medium in the cutting cup 4. Insert the treated cutting 1 along with the rooting accelerator paste 3 into the hole to a depth of 3-5 cm. Compact the medium at the base of the cutting 1 and then water it to establish rooting. The depth of the treated cutting 1 inserted into the hole should be 0.5-1 cm less than the hole itself. After this operation, gently compact the medium to fill the gap and then water it to establish rooting.

[0054] S6. Environmental Control: After grafting, maintain the temperature at 25-28°C and the relative humidity at 85%-88%. Keep the substrate moist but not waterlogged, and mist once or twice daily.

[0055] S7. Rooting management: 70-100 days after cutting, callus tissue begins to form at the base of cutting 1 and roots begin to form. After rooting, gradually reduce the frequency of spraying and increase the light intensity to promote seedling growth.

[0056] S8. Transplanting and maintenance: When the rooted cuttings grow to 12-14 cm, use a transplanting and burying device to transplant the root-proof cuttings 5 ​​together with the yellow heart soil 2 brought by the roots from the cutting cup 4 to the cultivation cup 7. The cultivation cup 7 is filled with the nutrient soil matrix 6. A 15×18 cm large hole is made in the center of the nutrient soil matrix 6. The dug rooted cuttings 5 ​​together with the yellow heart soil 2 at the roots are filled into the hole using the transplanting and burying device. After compaction, water is poured thoroughly. Subsequently, the cuttings are cultivated until they are suitable for field planting. The seedlings are then transplanted to the appropriate specifications; the transplanting and burying device is 15-18 x 18-20 cm (diameter x height), and the cultivation cup is 30-35 x 35-40 cm (diameter x height). The seedlings are then transplanted into a nutrient soil matrix 6, which is a mixture of peat moss, loess soil 2, and perlite in a volume ratio of 2:2:1. The matrix's physical and chemical properties are suitable for the growth of narrow-leaved sedge seedlings, and its air and water permeability facilitates root expansion and elongation. The matrix is ​​loaded with NPK slow-release microcapsules, containing a C:N ratio of 25:1, to ensure a continuous nutrient supply for the growing cuttings. From the day after transplanting to 90 days, cover the seedlings with a double layer of shade net with a shading rate of 60%-80%; 90 days after transplanting, remove one layer of shade net and keep one layer of shade net until the seedlings are transplanted; after transplanting, adjust the maintenance method of the seedlings according to the growth period of the narrow-leaved slope barrier seedlings (rapid growth period from March to September, slow growth period from October to November and stagnant period from December to February). March to September after transplanting is the rapid growth period of narrow-leaved sedge, and the corresponding maintenance method is to spray 0.1% compound fertilizer once a month, where the ratio of N:P:K contained in the compound fertilizer is 15:15:15, and it is used together with 0.05% chelated iron fertilizer solution to increase the chlorophyll content and growth rate of seedlings; October to November after transplanting is the slow growth period of narrow-leaved sedge, and the corresponding maintenance method is to spray 0.1% potassium dihydrogen phosphate once a month to improve the cold resistance of seedlings; December to February after transplanting is the growth stagnation period of narrow-leaved sedge, and the corresponding maintenance method is to stop fertilizing, and carry out watering and maintenance according to the dryness and wetness of the substrate to keep the moisture content of the substrate in the range of 50%-80%.

[0057] Example 1

[0058] A method for propagating the critically endangered tree species endemic to Guangxi, Angustifolia serrata, by root-injury-free hardwood cuttings, comprises the following steps:

[0059] S1. Cutting season: Choose mid-to-early January for cuttings;

[0060] S2. Cutting selection: Select strong and lush plants from a population with a large number of narrow-leaved sedges as mother plants, and cut lignified branches with axillary buds in the middle and lower parts of the crown as cuttings 1; the length of the cuttings 1 is controlled at 12 cm; retain 6 leaves and ensure that each cutting 1 has 3 or more buds; the thickness requirement is between 0.4 cm, and the lower part is cut into a 45° bevel.

[0061] S3. Cuttings treatment: The base of the cuttings 1 is immersed in a rooting promoter, the rooting promoter components include IBA500mg / L, GA325mg / L, IAA25mg / L, VB 12 200mg / L, VC50mg / L, KNO31g / L, Sargassum fermentation extract 3g / L; the rooting promoter is mixed with loess soil 2 to form a paste, and the base of the cutting 1 is buried in the rooting promoter paste 3 to a depth of 3.5cm for 30 hours;

[0062] S4. Cutting cup and substrate selection: Cutting cup 4 specifications are 10 × 12cm (diameter × height); cutting substrate is loess soil 2, the substrate is exposed to the sun 30 days in advance and sprayed with 0.1% carbendazim solution for disinfection, and drench with water 1 hour before cutting;

[0063] S5. Cutting method: Make a 4cm deep hole in the center of the cutting medium of the cutting cup 4, insert the treated cutting 1 together with the rooting promoter paste 3 into the hole to a depth of 3.5cm. After the operation is completed, gently compact the matrix to fill the gap, and then sprinkle with rooting water; the schematic diagram of the cutting 1 cutting into the cutting cup 4 is shown in Figure 6 ;

[0064] S6. Environmental Control: After cutting, maintain the temperature at 25-28°C and the relative humidity at 85%-88%. Keep the substrate moist but not waterlogged, and mist twice daily.

[0065] S7. Rooting management: 70-100 days after cutting, callus tissue begins to form at the base of cutting 1 and roots begin to form. After rooting, gradually reduce the frequency of spraying and increase the light intensity to promote seedling growth. See the cutting rooting process diagram. Figure 1 ;

[0066] S8. Transplantation and maintenance: When the rooted cuttings 5 ​​grow to 12 cm, use a transplanting and burying device to transplant the root-free cuttings 5 ​​together with the yellow soil 2 on the roots from the cutting cup 4 to the cultivation cup 7. The cultivation cup 7 is filled with the nutrient soil matrix 6. A 15×18 cm large hole is made in the center of the nutrient soil matrix 6. The dug rooted cuttings 5 ​​together with the yellow soil 2 on the roots are filled into the hole with the transplanting and burying device. After compaction, water is poured thoroughly. Subsequently, the cuttings are cultivated until suitable growth conditions are reached. The specifications of the seedlings planted in the wild are then transplanted out of the nursery; the specifications of the transplanting and burying device are 18×20cm (diameter×height), and the specifications of the cultivation cup 7 are 35×40cm (diameter×height); they are transplanted into the nutrient soil matrix 6, which is made by mixing peat soil, loess soil 2 and perlite in a volume ratio of 2:2:1. The physical and chemical properties of the matrix are suitable for the growth of narrow-leaved sedge seedlings, and the air permeability and water permeability of the matrix are conducive to the stretching and elongation of the roots of narrow-leaved sedge seedlings. And NPK slow-release microcapsules are loaded, wherein the elements C:N contained in the capsules are 25:1, to ensure the continuous nutrient supply for the growth of the cuttings. The schematic diagram of the rooted cuttings 5 ​​being transplanted into the cultivation cup 7 is shown in Figure 7 ; From the day after transplanting to 90 days, cover the seedlings with a double layer of shade net with a shading rate of 60%-80%; 90 days after transplanting, remove one layer of shade net and keep one layer of shade net until the seedlings are transplanted; after transplanting, adjust the maintenance method of the seedlings according to the growth period of the narrow-leaved slope barrier seedlings (rapid growth period from March to September, slow growth period from October to November and stagnant period from December to February). March to September after transplanting is the rapid growth period of narrow-leaved sedge, and the corresponding maintenance method is to spray 0.1% compound fertilizer once a month, where the ratio of N:P:K contained in the compound fertilizer is 15:15:15, and it is used together with 0.05% chelated iron fertilizer solution to increase the chlorophyll content and growth rate of the seedlings; October to November after transplanting is the slow growth period of narrow-leaved sedge, and the corresponding maintenance method is to spray 0.1% potassium dihydrogen phosphate once a month to improve the cold resistance of the seedlings; December to February after transplanting is the stagnation period of narrow-leaved sedge growth, and the corresponding maintenance method is to stop fertilizing, and carry out watering and maintenance according to the dryness and wetness of the substrate to keep the moisture content of the substrate in the range of 50%-80%. See the growth status diagram of rooted cutting 5. Figure 2 、 Figure 3 、 Figure 4 、 Figure 5 .

[0067] 1. Comparative test of cuttings in different seasons

[0068] The middle and lower branches of the strong and lush narrow-leaved sedge mother plants were selected as cuttings. They were pruned according to the above method. Comparative cutting tests were carried out in the nursery cutting shed in different seasons. The statistics are shown in Table 1:

[0069] Table 1: Comparative test data of cuttings in different seasons

[0070] Cuttings in different seasons Callus formation time (days) Rooting rate (%) Statistics spring 117 21.1 19 / 90 summer 123 13.3 12 / 90 Autumn 125 27.8 25 / 90 winter 119 67.7 61 / 90

[0071] Through comparative experiments, it was found that the survival rate of narrow-leaved sedge cuttings in different seasons was quite different. Among them, the survival rate of cuttings in winter was much higher than that in the other three seasons, which was more suitable for narrow-leaved sedge cutting operations.

[0072] 2. Comparative test of cuttings in different months

[0073] From mid-November to mid-February, we conducted comparative cutting trials of narrow-leaved sedge according to the above method to refine the optimal cutting operation time. The statistical data are shown in Table 2 below:

[0074] Table 2: Comparative test data of cuttings in different seasons

[0075] Different months Callus formation time (days) Rooting rate (%) Statistics mid-november 125 43.3 13 / 30 mid-december 120 70.0 21 / 30 mid january 119 76.7 23 / 30 mid february 119 56.7 17 / 30

[0076] The above data indicates that the peak survival period for narrow-leaved sedge cuttings is from mid-December to mid-January. The survival rate drops significantly in November and February. Therefore, mid-December to mid-January is the optimal period for growing narrow-leaved sedge. During this period, the sap flow is slow, nutrient reserves are abundant, and growth is ready to begin.

[0077] 3. Comparative test of different culture temperatures

[0078] Cuttings of S. angustifolia were collected in mid-December and three temperature conditions (25 / 22°C, 28 / 25°C, and 32 / 28°C) were set in an artificial climate incubator. A comparative test on the effect of different incubation temperatures on the rooting of S. angustifolia cuttings was conducted according to the above method. The statistical data are shown in Table 3:

[0079] Table 3: Comparative test data of different culture temperatures

[0080] Different temperatures (℃) Callus formation time (days) Rooting rate (%) Statistics 25 / 22 78 13.9 10 / 72 28 / 25 77 75.0 54 / 72 32 / 28 78 41.7 30 / 72

[0081] The results showed that a temperature range of 28 / 25°C was most conducive to the survival of L. angustifolia cuttings. We also found that callus formation could be significantly advanced under artificial temperature and humidity control (humidity in the artificial climate chamber was set at 85%-88%).

[0082] 4. Comparative test of cuttings with different diameters

[0083] Cuttings of Scutellaria serrata were collected in mid-January and placed in an artificial climate chamber set at a variable temperature of 28 / 25°C and a humidity of 85%-88%. Comparative tests of cuttings of different diameters were conducted according to the above method. The statistical data are shown in Table 4 below:

[0084] Table 4: Comparative test data of cuttings with different diameters

[0085] Cuttings of different diameters Callus formation time (days) Rooting rate (%) Statistics I<0.2cm 84 25.0 6 / 24 0.2cm≤I<0.4cm 75 79.2 19 / 24 0.4cm≤I<0.6cm 86 54.2 13 / 24 I≥0.6cm 87 20.8 5 / 24

[0086] The experimental investigation found that the survival rate of cuttings with a diameter of 0.2 ≤ ≤ 0.4 cm was the highest, followed by cuttings with a diameter of 0.4 cm ≤ ≤ 0.6 cm. This was likely due to the maturity of the cuttings. Cuttings with a diameter of 0.2 ≤ ≤ 0.4 cm had the best maturity and nutritional status, which was conducive to rooting and germination. Cuttings with a diameter of 0.4 cm ≤ ≤ 0.6 cm were slightly more mature, resulting in a lower survival rate. Cuttings with a diameter of less than 0.2 cm were too thin, immature, and lacked nutrient reserves. Cuttings with a diameter of ≥ 0.6 cm were too lignified, making them less conducive to survival.

[0087] 5. Comparative test of different rooting promoters

[0088] Cuttings of S. angustifolia were collected in mid-January and placed in an artificial climate chamber set at 28 / 25℃ and 85%-88% humidity. Comparative tests of different rooting promoters were carried out according to the above method. Preparation and treatment of rooting promoters: mother solutions of three different rooting promoters, IBA, ABT, and GGR, and prepared solutions (GA350 mg / L, IAA50 mg / L, VB 12 400mg / L, VC100mg / L, KNO32g / L, Sargassum fermented extract 6g / L) mother liquor, dilute the rooting promoter mother liquor to twice the corresponding concentration in the table, and mix it with the prepared liquid mother liquor in an equal volume ratio. The concentration of the contents is halved to obtain the corresponding rooting promoter mixture. These mixtures are mixed with loess soil respectively and the base of the cuttings is soaked for 30 minutes. The statistical data is shown in Table 5 below:

[0089] Table 5: Comparative test data of different rooting promoters

[0090] Different root growth promoters Callus formation time (days) Rooting rate (%) Statistics IBA1500ppm 82 22.2 16 / 72 IBA1000ppm 84 43.1 31 / 72 IBA500ppm 75 81.9 59 / 72 ABT No. 1 500ppm 95 54.2 39 / 72 GGR6 500ppm 118 41.7 30 / 72 Clearwater (CK) / 0 0 / 48

[0091] From the test data, we can see that IBA500ppm+GA325mg / L+IAA25mg / L+VB 12 The rooting rate of cuttings of S. angustifolia treated with 200mg / L+VC50mg / L+KNO32g / L+Sargassum fermentation extract 3 / L can reach 81.9%, and the callus formation time is advanced to 75 days. This combination is the best cutting treatment combination obtained during the experiment.

[0092] 6. Comparative test of different transplanting methods

[0093] In spring, the rooted cuttings of the narrow-leaved sedge seedlings were transplanted according to the above method. The effects of root-free transplanting and conventional transplanting on the narrow-leaved sedge seedlings were compared. The statistical data are shown in Table 6:

[0094] Table 6: Comparative test data of different transplanting methods

[0095]

[0096]

[0097] From the experimental data, it can be seen that root-free transplanting can shorten the recovery time of narrow-leaved sedge seedlings to 15 days, which is 33 days shorter than conventional transplanting. It can better shorten the cultivation cycle of narrow-leaved sedge seedlings and improve cultivation efficiency.

[0098] In summary, the series of experiments provided data support for the scientificity and reliability of the technical system of the present invention through single-factor variable control and multi-factor collaborative verification, proving that this method can effectively achieve efficient reproduction and population recovery of narrow-leaved slope barrier.

[0099] Those skilled in the art will recognize that numerous variations to the above description are possible, and that the examples are intended only to describe one or more specific implementations.

[0100] Although what is considered to be exemplary embodiments of the present invention has been described and illustrated, it will be understood by those skilled in the art that various changes and substitutions may be made thereto without departing from the spirit of the present invention. In addition, many modifications may be made to adapt a particular situation to the teachings of the present invention without departing from the central concept of the invention described herein. Therefore, the present invention is not limited to the specific embodiments disclosed herein, but rather encompasses all embodiments and their equivalents falling within the scope of the present invention.

[0101] It should be understood that the terms described herein are intended only to describe particular embodiments and are not intended to limit the present invention. In addition, for numerical ranges herein, it should be understood that each intermediate value between the upper and lower limits of the range is also specifically disclosed. The intermediate value within any stated value or stated range, and each smaller range between any other stated value or intermediate value within the stated range, is also encompassed within the present invention. The upper and lower limits of these smaller ranges may be independently included or excluded within the scope.

[0102] Unless otherwise indicated, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art. Although only preferred methods and materials are described herein, any methods and materials similar or equivalent to those described herein may also be used in the practice or testing of the present invention. All documents mentioned in this specification are incorporated by reference to disclose and describe the methods and / or materials associated with the documents. In the event of any conflict with any incorporated document, the contents of this specification shall prevail.

Claims

1. A method for propagating the critically endangered tree species of Guangxi, narrow-leaved sedge, by cuttings without damaging the roots, characterized in that: The following steps are involved: S1. Cutting season: Cuttings should be taken between mid-December and early-mid January. S2. Cutting Selection: Select robust, lush plants from a population with a high number of narrow-leaved sedges as mother plants. Cut woody branches with axillary buds in the lower and middle parts of the crown as cuttings. S3 cuttings treatment: soak the base of the cuttings into a rooting promoter, the rooting promoter is adjusted to a paste with loess heart soil, and the base of the cuttings is buried in the rooting promoter paste; S4. Cutting cup and substrate selection: Cutting cup specifications are 7-10 × 8-12 cm (diameter × height); cutting substrate is loess soil, the substrate is exposed to the sun 30 days in advance and sprayed with 0.1% carbendazim solution for disinfection, and watered thoroughly 1 hour before cutting; S5. Cutting Method: Fill a cutting cup with cutting medium. Make a small hole in the center of the medium. Insert the treated cuttings along with the rooting promoter paste into the hole to a depth of 3-5 cm. Compact the medium at the base of the cuttings and then water them with water to establish roots. S6. Environmental Control: After grafting, maintain the temperature at 25-28°C and the relative humidity at 85%-88%. Keep the substrate moist but not waterlogged, and mist once or twice daily. S7. Rooting Management: 70-100 days after cutting, callus tissue begins to form at the base of the cuttings and roots will form. After rooting, gradually reduce the frequency of spraying and increase the light intensity to promote seedling growth. S8. Transplanting and maintenance: When the rooted cuttings grow to 12-14 cm, use a transplanting and burying device to transplant them without damaging the roots. Transplant the rooted cuttings together with the yellow heart soil on the roots from the cutting cup to the cultivation cup. Fill the cultivation cup with nutrient soil matrix. Make a large hole of 15×18 cm in the center of the nutrient soil matrix. Use a transplanting and burying device to fill the dug rooted cuttings together with the yellow heart soil on the roots into the hole. After compacting, water it thoroughly. Subsequently, cultivate it to the seedling specifications suitable for wild planting and then plant it out in the nursery; from the day after transplanting to 90 days, cover the seedlings with a double layer of shade net with a shading rate of 60%-80%; 90 days after transplanting, remove one layer of shade net and keep one layer of shade net until the seedlings are transplanted; after transplanting, adjust the maintenance method of the seedlings according to the growth period of the narrow-leaved slope barrier seedlings (rapid growth period March-September, slow growth period October-November and stagnant period December-February).

2. The cutting propagation method according to claim 1, wherein In step S2, the length of the cuttings is controlled to be 10-12 cm; 4-6 leaves are retained to ensure that each cutting has 3 or more buds; the thickness is required to be between 0.2-0.4 cm, and the lower part is cut into a 45° bevel.

3. The cutting propagation method according to claim 1, wherein The rooting promoter in step S3 includes IBA 500 mg / L, GA 3 25 mg / L, IAA 25 mg / L, VB 12 200mg / L, VC50mg / L, KNO31g / L, Sargassum fermentation extract 3g / L.

4. The cutting propagation method according to claim 1, wherein In the cutting treatment described in step S3, the base of the cutting is buried in the rooting promoter paste to a depth of 3.5 cm for 30 hours.

5. The cutting propagation method according to claim 1, wherein In step S5, the cutting method involves making a small hole 4-6 cm deep in the center of the cutting medium in the cutting cup. The treated cuttings, along with the rooting promoter paste, are inserted into the hole to a depth of 3-5 cm. The medium at the base of the cuttings is compacted and then watered to establish rooting. The treated cuttings are inserted into the hole 0.5-1 cm less than the hole itself. After this operation is completed, the medium is gently compacted to fill the gap.

6. The cutting propagation method according to claim 1, wherein The specifications of the transplanting and burying device in step S8 are 15-18×18-20 cm (diameter×height), and the specifications of the cultivation cup are 30-35×35-40 cm (diameter×height).

7. The cutting propagation method according to claim 1, wherein The transplanting nutrient soil matrix described in step S8 is prepared by mixing peat moss, loess soil, and perlite in a volume ratio of 2:2:

1. The physical and chemical properties of the matrix are suitable for the growth of narrow-leaved sedge seedlings, and the matrix's air and water permeability facilitates the expansion and elongation of the narrow-leaved sedge seedlings' roots. The matrix is ​​loaded with NPK slow-release microcapsules, containing a C:N ratio of 25:1, ensuring a continuous nutrient supply for the growing cuttings.

8. The cutting propagation method according to claim 1, wherein The period from March to September after transplanting as described in step S8 is the rapid growth period of narrow-leaved slope barrier, and the corresponding maintenance method is to spray 0.1% compound fertilizer once a month, wherein the ratio of N:P:K contained in the compound fertilizer is 15:15:15, and it is used together with 0.05% chelated iron fertilizer solution to improve the chlorophyll content and growth rate of the seedlings.

9. The cutting propagation method according to claim 1, wherein The slow growth period of the narrow-leaved sedge is from October to November after transplanting in step S8, and the corresponding maintenance method is to spray 0.1% potassium dihydrogen phosphate once a month to improve the cold resistance of the seedlings.

10. The cutting propagation method according to claim 1, wherein The period from December to February after transplanting in step S8 is the growth stagnation period of narrow-leaved sedge, and the corresponding maintenance method is to stop fertilizing, carry out watering and maintenance according to the dryness and wetness of the substrate, and keep the moisture content of the substrate in the range of 50%-80%.

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