Composite plant growth regulator for Xanthoceras sorbifolia Bunge cuttage and cuttage method

Abstract

The invention relates to the technical field of plant propagation, and particularly discloses a composite plant growth regulator for Xanthoceras sorbifolia Bunge cuttage and a cuttage method. The active ingredients of the composite plant growth regulator comprise methyl anthranilate (ANT) and indolebutyric acid (IBA), wherein the concentration of ANT and the concentration of IBA are both 1-2 mM. The invention also provides a corresponding Xanthoceras sorbifolia Bunge cuttage method, which comprises the steps of cutting treatment, root-promoting soaking, cuttage culture and the like, and can further comprise carbendazim treatment, optimized matrix ratio and environmental parameter control. By means of the technical scheme, the rooting rate and the rooting number of the cuttings are remarkably increased, the rooting period is shortened, and the quality and survival stability of the root systems of the cuttings are improved. The regulator formula and the matched treatment method are suitable for large-scale vegetative propagation of xanthoceras sorbifolia bunge and have good application and popularization prospects.

Description

Technical Field

[0001] This invention belongs to the field of plant propagation technology, specifically relating to a compound plant growth regulator for cuttings of *Xanthoceras sorbifolium* and a method for cuttings of *Xanthoceras sorbifolium* using the regulator. Background Technology

[0002] In the field of plant propagation, cuttings, as a highly efficient method of asexual reproduction, can maintain the superior traits of the parent plant and are widely used in the propagation of improved tree varieties and seedling production. *Xanthoceras sorbifolium*, an important woody oilseed tree species in my country, possesses strong ecological adaptability and high economic value. In recent years, its application in energy forest construction, ecological restoration, and landscaping has become increasingly widespread, especially in arid and cold regions such as Northwest China, where it has become one of the important ecological tree species.

[0003] However, *Xanthoceras sorbifolium* is a difficult-to-root tree species with low natural propagation efficiency. Seedling propagation suffers from unstable offspring traits, significant variation, and late fruiting, making it difficult to meet the needs of large-scale planting and rapid dissemination of superior germplasm. Therefore, cutting propagation has become an important means to improve seedling efficiency and stability. However, existing *Xanthoceras sorbifolium* cutting propagation techniques still have significant limitations, such as low rooting rate of cuttings, long rooting cycle, slow callus formation, and large fluctuations in survival rate, which seriously restrict the mass production and high-quality supply of seedlings.

[0004] Plant growth regulators play a crucial role in promoting rooting of cuttings, particularly in controlling hormone levels, inducing callus formation, and promoting adventitious root development. Although conventional rooting agents such as indolebutyric acid (IBA) and naphthaleneacetic acid (NAA) exist on the market, these products are mostly general-purpose. There is a lack of research on specific formulations for the particular species *Xanthoceras sorbifolium*, especially for its different provenances or superior clones. As a result, their effectiveness is inconsistent, and their rooting effect is not ideal, making it difficult to achieve rapid and efficient propagation goals.

[0005] Furthermore, existing plant growth regulator formulations often fail to fully consider the synergistic effect of different active components in promoting rooting, leading to poor performance in specific application scenarios. Therefore, there is an urgent need to develop a compound plant growth regulator that combines high efficiency and stability, and to integrate it with cutting treatment methods tailored to the characteristics of *Xanthoceras sorbifolium*, in order to improve its rooting rate, shorten the rooting cycle, and enhance seedling quality, thereby promoting the large-scale dissemination and ecological engineering applications of superior *Xanthoceras sorbifolium* varieties. Summary of the Invention

[0006] In view of this, the purpose of this invention is to provide a compound plant growth regulator and a cutting method for *Xanthoceras sorbifolium* cuttings, in order to solve the problems of low rooting rate, long rooting period, poor root quality and unstable survival in existing *Xanthoceras sorbifolium* cuttings, thereby achieving the goal of improving the rooting efficiency and survival rate of cuttings.

[0007] To achieve the above objectives, the present invention provides the following technical solution: In one embodiment of the present invention, a compound plant growth regulator for cuttings of *Sapindus mukorossi* is provided, the active ingredients of which include methyl anthranilate (ANT) and indolebutyric acid (IBA).

[0008] Furthermore, the concentration of methyl anthranilate (ANT) is 1-2 mM, and the concentration of indolebutyric acid (IBA) is 1-2 mM.

[0009] In one embodiment of the present invention, a method for propagating *Sapindus mukorossi* by cuttings is provided, comprising the following steps: S1. Cutting treatment: Select semi-lignified branches of *Sapindus mukorossi* as cuttings; S2. Soaking to promote root growth: Soak the cuttings in the aforementioned compound plant growth regulator for 2 hours; S3. Cutting culture: The cuttings treated in step S2 are inserted into the substrate for culture.

[0010] Preferably, in step S1, the cuttings are selected from 2-year-old *Xanthoceras sorbifolium* branches, with a length of 10-15 cm, 2-3 internodes, and at least 1 axillary bud; the upper end of the cutting is cut horizontally, and the lower end is cut obliquely.

[0011] Optionally, after step S2 and before step S3, step S2a is also included: immersing the lower 2-3 cm of the cutting in a carbendazim solution for 10-15 seconds to prevent bacterial infection.

[0012] Preferably, in step S3, the matrix is ​​a mixture of loess and river sand.

[0013] Optionally, in step S3, the daytime temperature of the cultivation environment is 21-23℃, the humidity is 60-65%, and the nighttime temperature is not lower than 18℃, in order to provide a suitable rooting environment for the cuttings.

[0014] In one embodiment of the present invention, the compound plant growth regulator is used to promote rooting of *Xanthoceras sorbifolium* cuttings.

[0015] Furthermore, the method of application includes: soaking *Xanthoceras sorbifolium* cuttings in the compound plant growth regulator.

[0016] Preferably, the soaking time is 2 hours.

[0017] Based on the above technical solution, the compound plant growth regulator for *Xanthoceras sorbifolium* cuttings and its application method of the present invention, by combining methyl anthranilate (ANT) and indolebutyric acid (IBA), forms a root-promoting formula with significant synergistic effects, successfully solving the problems of poor compatibility and unstable root-promoting effects of existing rooting regulators for cuttings. Through scientifically optimized soaking time and concentration ratio, it effectively promotes the formation of adventitious roots and callus production in cuttings.

[0018] Specifically, the regulator in this invention exhibits excellent root-promoting effects at different concentrations. Particularly under conditions of 1-2 mM ANT and 1-2 mM IBA concentrations, the rooting rate of cuttings is significantly increased, the first rooting time of cuttings is advanced, and the root system is well-developed and abundant, demonstrating superior effects compared to existing commercially available rooting agents (such as rooting powder). Through comparative experiments, the number of roots in Examples 3 and 4 was significantly higher than the control group, with a rooting rate of 100%, significantly better than the treatment groups using only water treatment or commercial rooting agents, demonstrating the significant advantages of the regulator in the rooting of *Xanthoceras sorbifolium* cuttings.

[0019] Furthermore, the method described in this invention adds a short-term soaking step with carbendazim before cutting, effectively inhibiting the risk of root rot and improving the survival stability of the cuttings. Regarding cultivation conditions, by controlling a suitable temperature and humidity environment, the external conditions for rooting of the cuttings are further optimized, improving the overall effect of cutting propagation. The use of a mixed substrate of loess and river sand not only helps with drainage and aeration but also promotes root expansion and growth, enhancing seedling quality.

[0020] In summary, the compound plant growth regulator and the accompanying *Xanthoceras sorbifolium* cutting propagation method provided by this invention not only improve the rooting rate, rooting speed, and root quality of cuttings, but also significantly enhance the survival rate of cuttings and the consistency of seedlings. This provides a practical and feasible technical path for the large-scale, standardized propagation of *Xanthoceras sorbifolium*, possessing strong practical application prospects and promotional value. It is particularly suitable for meeting the needs of high-quality seedling propagation in forestry seedling bases, ecological restoration projects, and landscaping, thereby promoting the efficient development and utilization of *Xanthoceras sorbifolium* resources. Attached Figure Description

[0021] Figure 1 This is a comparison chart of the average number of roots formed by *Xanthoceras sorbifolium* cuttings after 35 days under different treatment conditions, used to reflect the effectiveness of the compound plant growth regulator provided by this invention in promoting rooting.

[0022] Figure 2 The image shows a comparison of the average root length of *Xanthoceras sorbifolium* cuttings after 35 days under different treatment conditions, demonstrating the effectiveness of the technical solution of this invention in improving root development quality. Detailed Implementation

[0023] To make the objectives, technical solutions, and beneficial effects of this invention clearer and more complete, the following detailed description of the compound plant growth regulator and the *Xanthoceras sorbifolium* cutting propagation method described in this invention, in conjunction with the accompanying drawings and embodiments, is provided. It should be understood that the described embodiments are for illustrative purposes only and are not intended to limit the scope of protection of this invention. Various equivalent substitutions or modifications that can be made by those skilled in the art based on this invention without departing from its core concept should be covered within the scope of protection of this invention.

[0024] I. Preparation methods of compound plant growth regulators In one embodiment of the present invention, the compound plant growth regulator consists of two active ingredients: methyl anthranilate (ANT) and indolebutyric acid (IBA). These are dissolved in a suitable solvent, mixed in a specific ratio, and finally brought to a fixed volume to form a root-promoting solution suitable for *Xanthoceras sorbifolium* cuttings. The preparation method is simple, the component ratios are clearly defined, and it is suitable for mass production and field application.

[0025] Example 1: ANT + IBA (1mM each) Weigh out the amount of ANT and IBA needed to prepare 200 mL of solution, so that the final concentrations of ANT and IBA are both 1 mM. The specific steps are as follows: 1. Dissolve ANT in a small amount of anhydrous ethanol and stir until completely dissolved to form ANT stock solution; the amount of ethanol should be just enough to dissolve ANT, and excessive amount should be avoided.

[0026] 2. Add the IBA powder to another portion of anhydrous ethanol and stir thoroughly to dissolve it, forming an IBA mother liquor. If dissolution is difficult, extend the stirring time instead of directly increasing the amount of ethanol.

[0027] 3. Mix the above ANT stock solution and IBA stock solution, add an appropriate amount of deionized water to make up to 200 mL, mix well and the compound plant growth regulator is obtained.

[0028] Example 2: ANT + IBA (2mM each) The preparation process in this embodiment is basically the same as in Example 1, except that the concentrations of ANT and IBA are each increased to 2 mM: 1. Weigh out ANT and IBA according to the 2mM ratio; 2. Dissolve each ingredient separately in an appropriate amount of anhydrous ethanol to prepare the mother liquor; 3. Mix the stock solution and add water to make up to 200 mL to form a high-concentration compound plant growth regulator.

[0029] Example 3: ANT single agent (1mM) To study the effect of ANT alone, the following steps were performed: 1. Weigh out ANT according to the 1mM ratio; 2. Dissolve ANT in a small amount of anhydrous ethanol. After complete dissolution, add deionized water and bring the volume to 200 mL. 3. After mixing, a plant growth regulator containing only ANT is obtained.

[0030] Example 4: ANT single agent (2mM) This embodiment follows the same steps as Example 3, except that the concentration of ANT is increased to 2 mM: 1. Weigh out ANT at a concentration of 2 mM; 2. Dissolve in anhydrous ethanol and stir thoroughly; 3. Add water to a final volume of 200 mL to obtain a solution.

[0031] Control group setup To verify the root-promoting effect of the above-mentioned regulators, the following control group was set up: Control group 1: Cuttings were treated with plain water without any growth regulators; Control group 2: Commercially available Guoguang brand rooting powder was diluted at a ratio of 800 times, i.e., 1.2g of rooting powder was weighed and diluted with water to 200mL, which served as a positive control.

[0032] By using the compound formulation and control group settings in the above embodiments, the effects of different treatments on the rooting ability of cuttings can be comprehensively compared in subsequent Xanthoceras sorbifolium cutting experiments, thereby verifying the root-promoting performance and application value of the regulator of the present invention.

[0033] II. Treatment and Cutting Procedures for *Xanthoceras sorbifolium* Cuttings This invention, based on plant growth regulators and combined with a scientific cutting treatment and propagation process, effectively improves the rooting efficiency and survival rate of *Xanthoceras sorbifolium* cuttings. Specifically, it includes steps such as cutting selection and preparation, chemical treatment, disease prevention, and cutting cultivation.

[0034] 1. Selection and cutting of cuttings In one embodiment of the present invention, semi-lignified branches that are healthy and free from pests and diseases from a robust 2-year-old *Sapindus mukorossi* mother plant are preferably selected as cuttings. These branches are rich in nutrients and have high physiological activity, making them suitable for rooting.

[0035] The cutting method for scions is as follows: Each cutting should be 10-15cm long and contain 2-3 internodes to facilitate rooting and subsequent bud sprouting. The upper part is cut flat, with the cut about 0.5cm away from the node, which helps to reduce water evaporation; The lower end is cut at a 45° angle, with the cut 0.5-1cm from the lowest node. This helps to increase the liquid absorption area and the rooting induction zone. Each cutting should retain at least one intact axillary bud to ensure its ability to sprout later; Use a clean, sharp knife to make the cut, ensuring a clean cut and minimizing mechanical damage.

[0036] After cutting, the cuttings should be placed in a cool, humid environment immediately to prevent them from wilting due to dehydration.

[0037] 2. Treatment with growth regulators (root-promoting treatment) Immerse the base of the treated cuttings in the compound plant growth regulator solution described in Examples 1-4, or in the corresponding control group solution, ensuring that the solution fully contacts the cut area.

[0038] Soaking depth: 2-3cm from the bottom of the cutting; Soaking time: Set to 2 hours uniformly, in a dark and well-ventilated environment; Do not shake or turn the cuttings during soaking; keep them in a stable soaking state.

[0039] Immediately after treatment, proceed with the next step of disease prevention and control pretreatment.

[0040] 3. Carbendazim treatment (preservative treatment) To prevent mold or root rot from occurring in high-humidity environments after cutting propagation, this invention adds a short-term soaking step in carbendazim solution after root-promoting treatment, thereby improving the healthy survival rate of cuttings.

[0041] Soak the lower 2-3cm of the cuttings again in the prepared carbendazim solution; The processing time is 10-15 seconds; After removing it, allow the surface to air dry naturally without rinsing.

[0042] This step can effectively inhibit the growth of pathogens at the cut site of the cuttings and improve the disease resistance of the cuttings during the cultivation process.

[0043] 4. Control of cutting propagation and cultivation conditions The processed cuttings should be propagated and managed as follows: Substrate selection: Use loess and river sand in an appropriate ratio, which has good water retention and air permeability, and is conducive to root growth; Seedbed preparation: Fill the seedbed with moist substrate with a thickness of not less than 15cm, and smooth the surface; Cuttings propagation: Insert the cuttings vertically into the substrate to a depth of 4-6 cm, ensuring they are stable and upright, arranged neatly, with treatment and control groups separated and clearly numbered and marked; Temperature and humidity control: The seedbed is placed in an artificial climate chamber for temperature and humidity controlled cultivation.

[0044] Daytime temperature should be kept at 22℃; The nighttime temperature should not be lower than 18°C; Relative humidity should be maintained at 60%-65%; Temperature and humidity control equipment should be inspected regularly to ensure stable parameters; Maintenance and management: Starting from the second day after cutting, observe the growth status of the cuttings every other day.

[0045] When the surface of the substrate is found to be dry, spray water as needed to replenish the moisture, keeping the substrate slightly moist but not saturated. Protect from direct sunlight and maintain partial shade. The cultivation period was set at 35 days, and indicators such as rooting progress and leaf condition were recorded throughout the process.

[0046] By controlling the cutting steps in the above-mentioned scientific and systematic manner, the consistency and repeatability of the experiment were effectively ensured, providing a reliable basis for subsequent effect evaluation.

[0047] III. Experimental Observation and Data Statistics To systematically evaluate the effect of the compound plant growth regulator provided by this invention on the rooting effect of *Xanthoceras sorbifolium* cuttings, a 35-day comparative experiment was conducted. The experimental subjects included the growth regulator treatment groups prepared in Examples 1 to 4, as well as control group 1 (water treatment) and control group 2 (commercially available Guoguang rooting powder treatment). Multiple indicators were set to comprehensively reflect the rooting ability and root development quality of the cuttings.

[0048] 1. Experimental Design Treatment groups: a total of 6 groups, including 4 case studies and 2 control groups; Cuttings were all collected from the same batch of healthy, uniformly developed 2-year-old *Xanthoceras sorbifolium* mother plants; Sample size per group: no less than 50 cuttings, to ensure that the sample size is statistically significant; Sampling principle: Following the random sampling method, 8 plants were randomly selected from each group for data measurement and recording; Cultivation period: uniformly set at 35 days, calculated from the date of completion of cutting; Recording frequency: Starting from day 2, observe and record the status of the cuttings every two days, focusing on recording the first rooting time, and finally uniformly measure the following indicators.

[0049] 2. Observation Indicators This invention evaluates the root-promoting effect of each treatment group using the following four main indicators: (1) Number of roots: The number of adventitious roots produced by each cutting is counted to reflect the root-promoting ability; (2) Length of the longest root (cm): Measure the length of the longest root in each plant to reflect the longitudinal growth potential of the root system; (3) First rooting days (days): Record the time when the first visible roots appear in each group to reflect the rooting induction speed; (4) Rooting rate (%): refers to the proportion of cuttings that have formed roots within 35 days out of all cuttings, indicating the overall level of successful rooting.

[0050] 3. Statistical Results The experimental data for each group are shown in Table 1 and Figure 1 , Figure 2 .

[0051] Table 1. Statistical table of rooting status of cuttings in different treatment groups (35 days) Processing Group Average number of roots (stalks) Length of the longest root (cm) First rooting days (days) Rooting rate (%) Control group 1 (water) 7.6 10.12 29 75.0 Control group 2 (rooting powder) 4.6 6.89 27 87.5 Example 1 (ANT + IBA 1mM) 20.9 6.61 21 87.5 Example 2 (ANT + IBA 2mM) 16.5 6.80 20 100.0 Example 3 (ANT1mM) 61.5 7.51 24 100.0 Example 4 (ANT2mM) 77.8 9.83 22 100.0 Figure 1 Bar chart comparing the average number of roots in each treatment group; Figure 2 Bar chart comparing the longest root lengths of each treatment group.

[0052] 4. Data Analysis and Results Description In terms of the number of roots, Examples 3 and 4 (ANT single agent) showed the most significant effects, with an average of 61.5 and 77.8 roots per plant, respectively, which were significantly better than other treatment groups. Regarding the rooting rate, Examples 2-4 all achieved a rooting rate of 100%, which is significantly better than the 75% of the water treatment and the 87.5% of the commercial rooting powder, indicating that the regulator of the present invention performs excellently in improving the survival rate. Regarding the rooting speed, the first rooting in Example 2 occurred on day 20, which was 7-9 days earlier than the control group, reflecting a significant root-promoting effect. Although the longest root in control group 1 was longer (10.12 cm), the number of roots was small and the root distribution was limited; while the treatment group treated with the regulator of the present invention achieved a good balance between the number of roots and the length of roots, and had better overall seedling performance.

[0053] In summary, the compound plant growth regulator provided by this invention, especially the single-component scheme based on ANT, has a significant effect on promoting root growth in *Xanthoceras sorbifolium* cuttings, which is superior to existing commercial products and has good prospects for practical application.

[0054] IV. Technical Effect Description To verify the practical effect of the compound plant growth regulator and its application method described in this invention on the propagation of *Xanthoceras sorbifolium* by cuttings, this invention designed a series of scientific and systematic comparative experiments, and visually presented the performance of each treatment group under different indicators through charts and graphs. The technical effects are as follows, in conjunction with the accompanying figures and data: 1. The number of roots has significantly increased (see...) Figure 1 Table 1) from Figure 1It is evident that Examples 3 (ANT1mM) and 4 (ANT2mM) significantly outperformed other groups in terms of average root number, reaching 61.5 and 77.8 roots respectively, which were far higher than those of the water treatment (7.6 roots) and the rooting powder treatment (4.6 roots).

[0055] This result indicates that: The regulator of this invention can effectively activate the cuttings to form a large number of adventitious roots; ANT single-agent treatment showed stronger root-promoting ability than IBA compound at certain concentrations; In contrast, commercially available general-purpose rooting powder is less effective in *Sapindus mukorossi*, a tree species that is difficult to root.

[0056] 2. Overall rooting rate improved As shown in Table 1, the rooting rates of Examples 2, 3 and 4 all reached 100%, while the rooting rate of water treatment was only 75% and that of Guoguang rooting powder treatment was 87.5%.

[0057] This indicates that: The formula of this invention can significantly improve the overall survival rate of cuttings; Cuttings show more consistent rooting performance, which is beneficial for standardized seedling cultivation; The regulator of this invention not only promotes the number of roots, but also improves the "stability" and "universality" of rooting.

[0058] 3. Rooting time is advanced and physiological response is accelerated. Regarding the first rooting time, the cuttings of Example 2 developed roots on the 20th day, which was 9 days earlier than the water group and also better than the commercial rooting powder group (27 days).

[0059] The modifier of the present invention comprises: The ability to induce callus and root primordia formation more quickly; It can shorten the seedling cycle and improve production efficiency, and is especially suitable for large-scale seedling production scenarios; The treated cuttings in the examples responded to rooting signals earlier under the same culture conditions, indicating that their physiological activity was enhanced.

[0060] 4. Optimized root system quality and sound structure Figure 2 The results showed that the longest root produced by Example 4 (ANT2mM) reached 9.83 cm, significantly better than Examples 1 and 2 (6.61 cm and 6.80 cm respectively), and slightly better than Example 3 (7.51 cm), approaching or even exceeding the water control (10.12 cm). However, considering that the number of roots in Example 4 was much higher than that in the control group, this indicates that: This invention not only encourages cuttings to grow more roots, but also forms longer and thicker taproots; The root system structure is more rational, which is conducive to the absorption of water and fertilizer in the later stage and the survival rate of transplanted plants; Compared to the control group, which has "long roots but few roots", the regulator of this invention achieves the comprehensive advantage of "many roots and long roots".

[0061] 5. Overall improvement in seedling performance Based on all experimental indicators: More roots mean stronger plant stability and absorption capacity; Longer roots → increase subsequent growth rate; Faster rooting → shorter production cycle and lower management costs; High rooting rate → ensures uniformity of seedlings and high nursery yield.

[0062] Therefore, the compound plant growth regulator of the present invention and its matching cutting propagation method can significantly improve the quality, efficiency and stability of *Xanthoceras sorbifolium* cutting propagation, and have obvious practical technical value and economic benefits.

[0063] In summary, this invention provides a compound plant growth regulator for *Xanthoceras sorbifolium* cuttings and a corresponding cutting method, which can effectively improve the rooting rate, number of roots, and root quality of cuttings, significantly shorten the rooting cycle, and improve seedling survival rate and uniformity. It overcomes the technical bottlenecks of low efficiency and unstable rooting in traditional cutting propagation. This invention is highly adaptable, easy to operate, and has good practical application value. It is particularly suitable for the large-scale seedling cultivation and seedling supply of *Xanthoceras sorbifolium* for ecological engineering projects, providing strong technical support for the efficient utilization of this tree species and its industrial development.

[0064] It should be understood that the above embodiments are merely preferred examples of the present invention, and the technical features described should not be construed as limiting the scope of protection of the present invention. All equivalent substitutions or modifications made based on the concept of the present invention should be covered within the scope of protection of the present invention. The scope of protection of the present invention is defined by the claims.

Claims

1. A composite plant growth regulator for Xanthoceras sorbifolia cutting, characterized in that, The active ingredients of the compound plant growth regulator include methyl anthranilate (ANT) and indolebutyric acid (IBA).

2. The composite plant growth regulator according to claim 1, characterized in that, The concentration of methyl anthranilate (ANT) is 1-2 mM, and the concentration of indolebutyric acid (IBA) is 1-2 mM.

3. A cutting method of Xanthoceras sorbifolia Bunge, characterized in that, Includes the following steps: S1. Cutting treatment: Select semi-lignified branches of *Sapindus mukorossi* as cuttings; S2, Soaking to promote root growth: Soak the cuttings in the compound plant growth regulator as described in claim 1 or 2 for 2 hours; S3. Cutting culture: The cuttings treated in step S2 are inserted into the substrate for culture.

4. The cutting method of Xanthoceras sorbifolia Bge. according to claim 3, characterized in that, In step S1, the cuttings are selected from 2-year-old *Xanthoceras sorbifolium* branches, with a length of 10-15 cm, 2-3 internodes, and at least 1 axillary bud; the upper end of the cuttings is cut horizontally and the lower end is cut obliquely.

5. The cutting method of Xanthoceras sorbifolia Bge. according to claim 3, characterized in that, After step S2 and before step S3, step S2a is also included: immersing the lower 2-3 cm of the cutting in a carbendazim solution for 10-15 seconds. 6.The cutting method of Xanthoceras sorbifolia Bunge according to claim 3, characterized in that, In step S3, the matrix is ​​a mixture of loess and river sand.

7. The cutting method of Xanthoceras sorbifolia Bge. according to claim 3, characterized in that, In step S3, the daytime temperature of the culture environment is 21-23℃, and the humidity is 60-65%; the nighttime temperature is not lower than 18℃.

8. The application of a compound plant growth regulator as described in claim 1 or 2 in promoting rooting of *Xanthoceras sorbifolium* cuttings.

9. Use according to claim 8, characterized in that, The method of application includes: soaking *Xanthoceras sorbifolium* cuttings in the compound plant growth regulator.

10. Use according to claim 9, characterized in that, The soaking time is 2 hours.

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