Method for different-layer multi-flower-color grafting of ornamental Chinese scholartree

Abstract

The invention provides a method for different-layer multi-flower-color grafting of ornamental Chinese scholartree, and belongs to the technical field of garden plant grafting. The method includes the following steps that sophora japonica seedlings which grow robustly and are free of pest and disease damage and have the diameter at breast height larger than or equal to 4 cm are selected as stocks; trunks are cut off at the positions 2.5 + / -0.2 m away from the ground before sprouting in early spring, cut openings are flattened and then smeared with a healing agent, and 3-5 robust bud points at the top ends are reserved; selecting chat red sophora japonica with the flower color of China purple, Huajian, Honghua 2, bright red 3 or purple 1 with the flower color of light pink or red, cobia 1 with the flower color of white or light yellow, Huazhuo, Huaxiang or a strong bud at the top end of the cut of the stock as a scion; and layered grafting design: planning a grafting layer according to a'deep-light 'color sequence. According to the method, interface singular damage is avoided through staged unbinding, and the problem of multi-variety symbiosis is solved.

Description

Technical Field

[0001] This invention relates to the field of grafting technology for garden plants, specifically to a method for grafting multi-colored, heterogeneous flowers onto ornamental Chinese scholar trees. Background Technology

[0002] The Chinese scholar tree (Styphnolobium japonicum), as an important landscaping tree species and traditional ornamental tree, is widely loved for its beautiful shape and strong adaptability. Traditional grafting techniques for Chinese scholar trees primarily serve two core purposes: first, variety improvement and trait optimization; and second, enhancing resistance and adaptability by utilizing the strong root system and stress resistance of the rootstock to improve the survival and growth performance of the scion variety in specific adverse environments (such as saline-alkali land and infertile soil). Although grafting techniques have played a significant role in the breeding and promotion of Chinese scholar tree varieties, existing techniques have significant shortcomings in achieving the specific goal of multi-layered, multi-colored, and composite ornamental effects.

[0003] 1. Single flower color: Traditional grafting usually involves grafting only a single variety of scion onto the same rootstock. For example, grafting a whole tree with golden locust (yellow flowers) or a whole tree with purple locust (purple flowers). As a result, a single Chinese scholar tree can only display a single flower color.

[0004] 2. Monotonous Layering: Grafting sites are usually concentrated in the same area of ​​the canopy (such as the branching point of the main branch or the upper part of the trunk), or multiple grafts are performed to form a relatively concentrated canopy layer. This results in relatively concentrated flowering sites and a lack of clear, layered flower color distribution along the longitudinal direction (height) of the trunk.

[0005] 3. Difficulty in achieving the effect of "different layers and multiple colors": Existing grafting methods and techniques have failed to effectively solve the key problem of stably and coordinately grafting and cultivating multiple varieties with significant differences in flower color (such as yellow, purple and white flowers) at different height levels on the same Chinese scholar tree trunk. Summary of the Invention

[0006] This application addresses the technical bottleneck of grafting multiple varieties onto the same rootstock on a single tree trunk. This is achieved through a series of technical measures, including rootstock-scion combination design, color gradient design, rootstock treatment, scion treatment, layered grafting design, optimized grafting techniques, and post-grafting dynamic management. These measures aim to overcome the problem of some varieties growing too vigorously and inhibiting other varieties, or some varieties having poor compatibility leading to poor growth or even death. The goal is to achieve a stable, harmonious, and highly ornamental multi-color combination effect.

[0007] To achieve the above-mentioned objectives, the present invention provides the following technical solution: A method for grafting ornamental Chinese scholar trees with heterogeneous multi-colored flowers includes the following steps:

[0008] (1) Rootstock selection and treatment: Select healthy, disease-free, and diameter-at-breast-length Sophora japonica seedlings with a diameter at breast height of ≥4cm as rootstocks; cut the main trunk at 2.5±0.2 meters above the ground before the first buds sprout in early spring, smooth the cut surface and apply a wound healing agent, and retain 3-5 healthy buds at the top.

[0009] (2) Scion selection: Select the following as scions: the following are ...

[0010] (3) Layered grafting design: Grafting layers are planned according to the color sequence of "dark → light";

[0011] (4) Grafting operation: The bark grafting method is adopted. Make a "T" shaped cut at the target grafting position on the rootstock, reaching the xylem; the scion is a 1-year-old lignified branch, 8-10cm long, retaining 3-5 plump buds. After treating the base with 0.1% IAA solution for 10 minutes, cut it into a double-sloped wedge shape, and lightly cut 0.5cm on the back to expose the white part; insert the scion into the cut, align the cambium layers, and make the "exposed white part" fit against the rootstock;

[0012] (5) Post-grafting management: The graft union is tightly wrapped with grafting film, and the scion is wrapped with a thin plastic bag; the binding is removed in stages.

[0013] Preferably, step (3) of the layered grafting design includes:

[0014] First layer: 60cm below the cut, evenly distribute 3-4 branches of Locust simonii in the radial direction, with the scion inserted at an angle of 60° upwards.

[0015] Second layer: 20-40cm below the cut, graft 2-3 branches of Huajian or Hongfen No. 2, with the scion inserted at an angle of 45° upwards.

[0016] Third layer: Retain 3-5 healthy buds at the cut end of the rootstock to form the top corolla.

[0017] Preferably, the phased untying in step (5) is as follows: loosen 1 / 3 of the binding 20 days after grafting, loosen to 2 / 3 after 40 days, and completely untie after 60 days; spray the leaves with 0.2% potassium dihydrogen phosphate when the new shoots grow to 10cm, once every 15 days, for a total of 3 times; and make the tree crown into an umbrella-shaped structure through pruning and branch pulling.

[0018] Preferably, the wound healing agent in step (1) comprises a bactericide and a growth factor.

[0019] Preferably, in step (3), the first and second layers of scions are evenly distributed on the rootstock at their azimuth angles.

[0020] Preferably, the vertical cut length of the "T" shaped cut in step (4) is 3cm and the horizontal cut length is 1cm.

[0021] Preferably, the unbinding process in step (5) includes checking the healing of the interface and removing any grafting residue.

[0022] More preferably, the foliar spraying in step (5) is carried out outside of high-temperature periods.

[0023] The present invention also provides a grafting structure, including a Chinese scholar tree rootstock and multiple scions of different flower colors grafted onto it. The scions are distributed in three layers according to the gradient of color depth: the lower layer is purplish-blue, the middle layer is pink or red, and the upper layer is white or light yellow. The insertion angle of each layer of scions is designed to form an umbrella-shaped crown.

[0024] Compared with the prior art, the present invention achieves the following technical effects:

[0025] 1. Systematic hierarchical design:

[0026] By adjusting the stem height and using a three-layer gradient positioning (purple flowers 60cm below the cut, pink or red in the middle, and white flowers at the top), an orderly distribution of flower colors is achieved vertically. The principle of color visual weight (dark colors sink, light colors rise) is utilized to enhance the layered, three-dimensional effect.

[0027] 2. Innovative grafting structure:

[0028] Treating the base of the scion with 0.1% IAA solution for 10 minutes increases the speed of callus formation. Improving the bark grafting technique combined with "exposed white" treatment expands the callus contact area. Scientific binding and wrapping after grafting prevents water from entering the graft union and water loss from the scion. These measures all ensure an increased grafting survival rate.

[0029] Inserting the wedge-shaped end of the scion at the designed angle is beneficial for space competition and nutrient distribution.

[0030] 3. Dynamic management mechanism:

[0031] Phased debining avoids interface damage and solves the problem of multi-product symbiosis. Attached Figure Description

[0032] For ease of explanation, the present invention will be described in detail below with reference to specific embodiments and accompanying drawings.

[0033] Figure 1 This is a photograph of the graft union of the Sophora japonica tree in this invention;

[0034] Figure 2 This is a photo of a Chinese scholar tree after grafting according to the present invention. Detailed Implementation

[0035] The following are specific embodiments of the present invention, described in conjunction with the accompanying drawings, to further illustrate the technical solutions of the present invention. However, the present invention is not limited to these embodiments. Specific details, such as particular configurations, are provided in the following description merely to aid in a comprehensive understanding of the embodiments of the present invention. Therefore, those skilled in the art should understand that various changes and modifications can be made to the embodiments described herein without departing from the scope and spirit of the present invention.

[0036] This invention provides a method for grafting ornamental Chinese scholar trees with heterogeneous and multicolored flowers, comprising the following steps:

[0037] 1. Rootstock-scion combination design

[0038] For rootstock, select Chinese scholar tree seedlings with straight trunks, vigorous growth, no pests or diseases, and a diameter at breast height (DBH) ≥ 4cm. For grafting varieties, select Liaohonghuai (purple) with darker flower color, Huajian (light pink), Hongfen No. 2 (light pink), Yanhong No. 3 (deep pink), and Chazi No. 1 (red) with red or pink flowers, Caozhou No. 1 (white), Huashuo (white), and Huaxiang (white) with light yellow or white flowers, or Chinese scholar tree seedlings (with strong buds at the top of the rootstock cut).

[0039] 2. Color gradient design:

[0040] Plan the grafting layers according to the color sequence of "dark → light": bottom layer (dark purple) → middle layer (pink or red) → top layer (light yellow or white).

[0041] 3. Rootstock treatment

[0042] Timing of trunk pruning: Prune the trunk in early spring before bud break (early stage of sap flow) to reduce nutrient loss from the tree and improve its healing ability.

[0043] Trunk cutting height: The main trunk is precisely cut off at 2.5±0.2 meters above the ground, leaving enough height to accommodate both viewing angles and the need for layered space.

[0044] Cutting treatment: After the cut surface is flattened, apply a wound healing agent (containing fungicide and auxin) immediately to seal the wound and promote callus differentiation and wound healing; retain 3-5 strong buds at the top to provide a source of branches for the top layer of original white flowers.

[0045] 4. Layered grafting design

[0046] Table 1 Layered Grafting Design

[0047]

[0048] 5. Improved skin grafting technology

[0049] Rootstock treatment:

[0050] Make a T-shaped incision (vertical cut 3cm long, horizontal cut 1cm long) at the target layer location point, reaching the xylem but avoiding damage to the cambium.

[0051] Scion treatment:

[0052] Select one-year-old lignified branches and cut them into scions 8-10cm long. Treat the base of the scion with 0.1% IAA solution for 10 minutes and cut it into a double-sloped wedge shape (3cm long, retaining 3-5 plump buds). Lightly cut 0.5cm on the back of the sloping base to expose the white part and increase the callus area.

[0053] Grafting procedure:

[0054] Pry open the bark of the "T" cut and insert the wedge-shaped end of the scion at the designed angle, ensuring that the cambium layers are aligned; the exposed white part of the scion should fit against the rootstock cut to enhance healing stability.

[0055] 6. Post-acceptance management

[0056] Binding, wrapping:

[0057] Starting below the graft union, the grafting film is tightly, evenly, and securely wrapped around the scion from bottom to top. A thin, convenient bag is opened, leaving a small amount of air inside, and used to completely cover the scion to prevent rainwater from entering the graft union.

[0058] Dynamic unbinding:

[0059] Table 2 Dynamic Unbinding Technology

[0060]

[0061] Nutritional regulation:

[0062] When the new shoots reach 10cm in length, spray the leaves with 0.2% potassium dihydrogen phosphate to promote flower bud differentiation and lignification. Spray once every 15 days for three consecutive times, avoiding high-temperature periods.

[0063] Plastic surgery:

[0064] After grafting, through pruning and branch pulling techniques, the new shoots of the upper and middle layers of scions grow outward at a 45° angle, while the new shoots of the lower layers of scions grow outward at a 60° angle, forming an umbrella-shaped crown.

[0065] Example 1

[0066] In this example, a 3-year-old, straight, vigorous, disease-free Chinese scholar tree rootstock with a diameter at breast height (DBH) ≥ 4cm was selected. On March 15, 2023, the rootstock was cut at a height of 2.5m, and wound healing paste was applied to the cut surface. The following steps were followed:

[0067] 1. Graft four branches of Sophora japonica and Sophora pubescens (with a height difference of 5cm and an azimuth angle of 90°) 60cm below the cut.

[0068] 2. Graft three branches of Chinese scholar tree (with a height difference of 3cm and an azimuth angle of 120°) 30cm below the cut.

[0069] 3. Retain three strong buds that slant upwards at the top.

[0070] Specific grafting procedures:

[0071] Rootstock preparation: Make a "T" shaped cut (vertical cut 3cm long, horizontal cut 1cm long) at the target layer location point, reaching the xylem but avoiding damage to the cambium.

[0072] Scion treatment: Select 1-year-old lignified branches, cut them into scions 8cm-10cm long, treat the base of the scion with 0.1% IAA solution for 10 minutes, and cut it into a double-sloped wedge shape (3cm long, retaining 3-5 plump buds); lightly cut 0.5cm on the back of the sloping base to expose the white part and increase the callus area.

[0073] Grafting procedure: Pry open the bark of the "T" cut, insert the wedge-shaped end of the scion at the designed angle, and ensure that the cambium layers are aligned; the "exposed white" part of the scion should be placed against the rootstock cut to enhance healing stability.

[0074] 4. Post-acceptance management

[0075] Binding and wrapping: Starting below the graft union, the grafting film is tightly, evenly, and securely wrapped around the scion from bottom to top. Open a thin plastic bag, leaving a small amount of air inside, and completely wrap the scion to prevent rainwater from entering the graft union.

[0076] 20 days after grafting, loosen the binding by 1 / 3 and check the healing progress; 40 days after grafting, loosen the binding to 2 / 3, leaving some support; 60 days after grafting, completely remove the binding and clean the graft union residue.

[0077] Those skilled in the art to which this application pertains may make various modifications or additions to the specific embodiments described, or adopt similar methods to replace them, without departing from the inventive concept of this application or exceeding the scope defined by the appended claims.

Claims

1. A method for grafting multi-colored, heterophyllous flowers onto ornamental Chinese scholar trees, characterized in that... Includes the following steps: (1) Rootstock selection and treatment: Select healthy, disease-free, and diameter-at-breast-length Sophora japonica seedlings with a diameter at breast height of ≥4cm as rootstocks; cut the main trunk at 2.5±0.2 meters above the ground before the first buds sprout in early spring, smooth the cut surface and apply a wound healing agent, and retain 3-5 healthy buds at the top. (2) Scion selection: Select the following as scions: the following are ... (3) Layered grafting design: Grafting layers are planned according to the color sequence of "dark → light"; (4) Grafting operation: The bark grafting method is adopted. A "T" shaped incision is made at the target grafting position on the rootstock, reaching the xylem. The scion is a one-year-old lignified branch, 8-10cm long, retaining 3-5 plump buds. After the base is treated with 0.1% IAA solution for 10 minutes, it is cut into a double-sloped wedge shape, and the back is lightly cut 0.5cm to expose the white part. Insert the scion into the incision, align the cambium layers, and make the "exposed white part" fit against the rootstock. (5) Post-grafting management: The graft union is tightly wrapped with grafting film, and the scion is wrapped with a thin plastic bag; the binding is removed in stages.

2. The method according to claim 1, characterized in that, The layered grafting design in step (3) includes: First layer: 60cm below the cut, evenly distribute 3-4 branches of Locust simonii in the radial direction, with the scion inserted at an angle of 60° upwards. Second layer: 20-40cm below the cut, graft 2-3 branches of Huajian or Hongfen No. 2, with the scion inserted at an angle of 45° upwards. Third layer: Retain 3-5 healthy buds at the cut end of the rootstock to form the top corolla.

3. The method according to claim 1, characterized in that, The phased untying in step (5) is as follows: loosen 1 / 3 of the binding 20 days after grafting, loosen 2 / 3 of the binding 40 days after grafting, and completely untie the binding 60 days after grafting; spray the leaves with 0.2% potassium dihydrogen phosphate when the new shoots grow to 10cm, once every 15 days, for a total of 3 times; and make the crown into an umbrella-shaped structure by pruning and pulling branches.

4. The method according to claim 1, characterized in that, The wound healing agent described in step (1) contains a bactericide and a growth factor.

5. The method according to claim 1, characterized in that, In step (3), the first and second layers of scions are evenly distributed on the rootstock.

6. The method according to claim 1, characterized in that, The vertical cut length of the "T" shaped cut in step (4) is 3cm, and the horizontal cut length is 1cm.

7. The method according to claim 1, characterized in that, The unbinding process described in step (5) includes checking the healing of the interface and removing any remaining grafting material.

8. The method according to claim 1, characterized in that, The foliar spraying described in step (5) should be carried out during periods of high temperature.

9. A grafting structure, characterized in that, It includes Chinese scholar tree rootstock and scions of various flower colors grafted onto it. The scions are distributed in three layers according to the color gradient: the lower layer is purplish-blue, the middle layer is pink or red, and the upper layer is white or light yellow. The insertion angle of each layer of scions is designed to form an umbrella-shaped crown.

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