Sweet persimmon grafting planting method

Abstract

The invention discloses a sweet persimmon grafting planting method, which belongs to the technical field of sweet persimmon grafting, and performs grafting planting on sweet persimmons through the steps of scion collection and treatment, rootstock selection and treatment, grafting, transplanting, later-stage management and protection and the like. And a healing-promoting bandage capable of promoting healing of the graft union and preventing infection of the graft union is prepared to bind the graft union and guarantee good conditions for healing of the graft union, so that the grafting survival rate of the sweet persimmons is guaranteed, good growth of grafted seedlings in the later period is promoted, development of the sweet persimmon industry is promoted, and good application prospects are achieved.

Description

Technical Field

[0001] The present invention relates to the technical field of sweet persimmon grafting, in particular to a sweet persimmon grafting planting method. Background Art

[0002] Sweet persimmons are a uniquely Oriental fruit. They naturally lose their astringency upon ripening, resulting in a unique flavor characterized by freshness, color, sweetness, crispness, and a refreshing taste. They are known as the "treasure of fruits." Their nutritional and health benefits surpass those of astringent persimmons, making them highly commercially viable and competitive, with broad development prospects. However, the vast majority of cultivated persimmon varieties in my country are astringent, and the area devoted to sweet persimmon cultivation accounts for less than 2% of the total persimmon planting area, far from meeting market demand.

[0003] In the cultivation practice of sweet persimmons in my country, grafting is the main method of propagation, and most of the main cultivated varieties are introduced from Japan. There are significant differences in rootstock affinity between Japanese sweet persimmons and traditional astringent persimmons grown in my country, and different varieties of sweet persimmons have different requirements for rootstocks. By selecting rootstocks and scions with good affinity for grafting, the healing of the rootstock and scion between sweet persimmon grafts can be ensured. However, there is currently a lack of a systematic and comprehensive evaluation system for the affinity of rootstocks and scions for sweet persimmons, making it difficult to screen out excellent rootstocks suitable for all sweet persimmon varieties. Therefore, in actual production, the poor affinity between the rootstock and scion often leads to difficulties in graft healing and low graft survival rates, which seriously restricts the development of the sweet persimmon industry.

[0004] Environmental factors during the grafting process also have a crucial impact on the healing of the grafting site. Temperature, humidity, and pathogen infection are all key factors affecting the healing effect of the grafting site. In traditional grafting methods, plastic film bands are usually used to fix the stock and scion, and in this way, the humidity and temperature of the grafting site are maintained, while isolating the invasion of external pathogens. However, this plastic film is not ideal in maintaining humidity and preventing pathogen infection, and due to its poor air permeability, it is easy to cause poor air permeability of the grafting site, affecting the respiratory metabolism of cells and inhibiting the normal healing of the grafting site.

[0005] Therefore, a sweet persimmon grafting method is currently being sought to solve the problems of difficult healing of the sweet persimmon grafting site and low grafting survival rate due to poor affinity between the rootstock and the scion and limitations of environmental factors such as humidity and air permeability under traditional grafting methods. Summary of the Invention

[0006] In view of this, the purpose of the present invention is to provide a grafting planting method for sweet persimmons, which solves the problems of difficult healing of the sweet persimmon grafting site and low grafting survival rate due to poor affinity between the rootstock and the scion, as well as limitations of environmental factors such as humidity and air permeability under traditional grafting methods.

[0007] The present invention solves the above technical problems through the following technical means:

[0008] A method for grafting and planting sweet persimmons, comprising the following steps:

[0009] (1) Scion collection and processing: From December to January of the following year, collect one-year-old sweet persimmon branches that are healthy, have full buds, and are free of pests and diseases as scions. Cut the collected scions into segments 8 to 15 cm long with 2 to 4 buds, wrap them in wet cloth, and store them at 4°C until use.

[0010] (2) Rootstock selection and treatment: From mid-March to early April, select 1-2 year old wild persimmons that are healthy and free of pests and diseases as rootstocks. Cut the rootstock 15-30 cm from the ground, remove the side branches and buds, and then flatten the cross section of the rootstock with a knife. Then cut vertically downward from the center of the cross section of the rootstock with a depth of 2-3 cm. Then spray the cross section and the cut with a mixture of zinc sulfate and copper sulfate.

[0011] (3) Grafting: After the scion is taken out, the lower end is cut into a 2-3 cm wedge shape, so that the length of the wedge surface is equivalent to the depth of the stock incision, and the cut surface of the scion is ensured to be smooth. The cut scion is inserted into the incision of the stock, so that the cambium of the scion and the stock are closely aligned, and then the grafting site is tightly bandaged with a healing bandage coated with a healing gel. After the bandage is completed, a hole is pricked in the bandage with a needle to obtain a grafted seedling;

[0012] (4) Transplantation and post-management: From November to December, select healthy, disease-free, and fully budded grafted seedlings for transplanting. When transplanting, dig a planting hole first, place the grafted seedling in the planting hole and straighten it, then backfill the soil into the planting hole and tamp it down, and water it thoroughly. In the later stage, watering, fertilizing, pruning and other maintenance operations can be carried out according to conventional methods.

[0013] Furthermore, the zinc sulfate-copper sulfate mixed solution in step (2) is obtained by mixing zinc sulfate and copper sulfate in a mass ratio of 1:2, weighing the mixture, and then adding the mixture to 300 times the mass of water to dissolve the mixture.

[0014] When grafting sweet persimmons, the present invention uses a zinc sulfate-copper sulfate mixture to spray the incision. On the one hand, the zinc and copper ions in the mixture can regulate the enzyme activity in the plant body and promote the healing of the grafting site. On the other hand, a relatively high concentration of copper ions can induce the grafting site to produce active oxygen. An appropriate amount of active oxygen can effectively inhibit pathogen infection and promote lignification of the grafting wound, thereby preventing the wound from being exposed to the natural environment and infected by pathogens during the grafting process, better promoting the healing of the grafting site, and ensuring the grafting survival rate.

[0015] Furthermore, the preparation method of the healing-promoting bandage is as follows:

[0016] A: Mannitol was dissolved in water to prepare a 20 wt% mannitol solution. Nanohydroxyapatite was added to the mannitol solution, stirred and dispersed, and then refrigerated at 4°C overnight. The mixture was then freeze-dried in a vacuum oven and ground and sieved to obtain composite microparticles. The composite microparticles were added to 60°C water and slowly stirred for 5 minutes. The mixture was then naturally cooled to room temperature. The filtrate was then filtered to obtain porous composite microparticles for later use.

[0017] B: Gelatin was added to water and stirred to disperse, and lauric acid was dissolved in ethanol and added, followed by addition of p-toluenesulfonic acid. The temperature was raised to 70-80°C and stirred for reaction for 6-8 hours. After the reaction was completed, the temperature was lowered to 50°C, D-galacturonic acid was added, stirred and mixed, and the pH was adjusted to 6.5. The reaction was continued with stirring for 20-30 minutes, and then the porous composite particles and indoleacetic acid were added, mixed and mixed, and then naturally cooled to room temperature. The mixture was transferred to 4°C and refrigerated overnight to obtain a healing gel.

[0018] C: The polylactic acid film was cut into rectangles and then coated with healing gel to obtain a healing bandage.

[0019] The present invention also prepares a healing-promoting bandage to bind the grafting site, which better promotes the healing of the grafting site and improves the grafting survival rate. Specifically, the healing-promoting bandage is prepared by coating a healing gel with a polylactic acid film as a membrane substrate. The healing gel is prepared by using gelatin as a matrix and loading porous composite particles and indoleacetic acid. After the healing-promoting bandage is tied to the grafting site and holes are punched, the healing gel can slowly and continuously release indoleacetic acid to promote the rapid formation of callus tissue and the reconnection of vascular bundles, thereby promoting the healing of the grafting site and shortening the healing time. The nano-hydroxyapatite in the porous composite particles further loaded can be ion-exchanged with the copper sulfate sprayed previously, so that the grafting site continues to absorb calcium ions and replace the copper ions, preventing the long-term action of higher concentrations of copper ions from causing excessive accumulation of reactive oxygen species, which in turn causes oxidative damage to cells. The absorbed calcium ions can promote the cross-linking of the cell walls of the grafting site and further promote the healing of the grafting site.

[0020] The present invention uses gelatin as a gel matrix material to load other components to prepare a healing gel. The prepared gel has strong water absorption and water retention properties and can provide moisture for a long time to meet the needs of the plant grafting site. However, a gel matrix with too high a water content is likely to hinder the entry and exit of metabolic gases, and a high humidity environment is likely to promote the proliferation of pathogens. Therefore, the present invention uses lauric acid with an antibacterial effect to treat the gelatin. After chemical bonding with the gelatin, the lauric acid shields its water absorption active sites, thereby reducing the water adsorbed by the gel and reducing the water held by the healing gel to a certain extent. This can ensure that the cells at the grafting site are provided with relatively sufficient water, and can also prevent excessive water from hindering gas exchange and promoting the proliferation of pathogens.

[0021] In addition, in order to ensure that the healing bandage can continuously provide calcium ions to exchange with the higher concentration of copper ions in copper sulfate, the present invention adopts mannitol and nano-hydroxyapatite mixed and refrigerated at low temperature, and then treated with hot water to prepare porous composite particles loaded in the healing gel. During the low-temperature refrigeration process, mannitol crystallizes to form a solid and is prepared into composite particles together with nano-hydroxyapatite. When placed in hot water, the crystallized mannitol dissolves in hot water to form porous composite particles with more pore channels, which greatly improves the air permeability of the healing gel and exposes more calcium ion sites. On the other hand, the mannitol remaining in the composite particles can increase the water absorption sites inside the composite particles, thereby promoting the migration of water in the gel to the interior of the porous composite particles, prompting the nano-hydroxyapatite to hydrolyze and release active calcium ions. The calcium ions are then exchanged with copper ions to replace the copper ions, inhibiting the excessive generation of reactive oxygen species in the later stage, and promoting the cross-linking of the cell wall of the grafting site through calcium ions, thereby accelerating the healing of the grafting site. Through the combined action of various components in the healing gel, the grafting site is provided with suitable humidity and good air permeability, the infection of pathogens is inhibited, and indoleacetic acid, calcium ions, etc. are continuously provided. The multi-faceted effects promote the healing of the grafting site, improve the grafting survival rate, and ensure the good growth of the grafted seedlings.

[0022] Furthermore, in step A, the mass ratio of mannitol to nano-hydroxyapatite is (0.1-0.2): (0.6-1).

[0023] Furthermore, the vacuum freeze-drying condition in step A is drying at -50°C for 24 hours.

[0024] Furthermore, in the step A, the composite particles are ground and then passed through a 50-mesh sieve.

[0025] Furthermore, in step B, the mass ratio of gelatin, lauric acid, p-toluenesulfonic acid, D-galacturonic acid, porous composite particles, and indoleacetic acid is (0.06-0.1): (0.012-0.02): (0.0006-0.001): (0.01-0.02): (0.6-1): (0.0001-0.0002).

[0026] Furthermore, in step C, the polylactic acid film is cut into a rectangle with a length of 20 to 30 cm and a width of 4 to 6 cm.

[0027] Furthermore, the coating thickness of the healing gel in step C is 2 to 3 mm.

[0028] Preferably, in order to save materials, healing gel can be applied only at one end of the membrane to prepare a healing bandage. When bandaging the grafting interface, first stick the end coated with healing gel to the grafting interface, and then continue to wrap the remaining healing bandage around the grafting interface to tighten the interface.

[0029] Beneficial effects:

[0030] 1. The present invention sprays a zinc sulfate-copper sulfate mixture of a certain concentration on the incision during sweet persimmon grafting. The zinc ions and copper ions can regulate the enzyme activity in the plant body and promote the healing of the grafting site. The copper ions have a strong bactericidal effect, which can prevent the grafting site from being infected by pathogens during the grafting process, and induce the generation of a small amount of active oxygen, thereby further inhibiting pathogen infection and promoting wound lignification and accelerating wound healing.

[0031] 2. The present invention prepares a healing-promoting bandage to bind the grafting site of the sweet persimmon. The healing-promoting bandage continuously releases indoleacetic acid and calcium ions to promote the healing of the grafting site, and ensures that the grafting site has suitable humidity and air permeability, creating good conditions for the healing of the grafting site, further ensuring better healing of the interface, improving the grafting survival rate, and promoting the good growth of the grafted seedlings. DETAILED DESCRIPTION

[0032] The present invention will be described in detail below with reference to specific embodiments:

[0033] Example 1: Preparation of a healing bandage

[0034] A: Dissolve 0.15 kg of mannitol in water to prepare a 20 wt% mannitol solution. Add 0.8 kg of nanohydroxyapatite to the mannitol solution, stir and disperse, refrigerate at 4°C overnight, then freeze-dry at -50°C for 24 hours, and grind through a 50-mesh sieve to obtain composite particles. Add the composite particles to 60°C water, slowly stir for 5 minutes, and naturally cool to room temperature. Then, filter and remove the filtrate to obtain porous composite particles for later use.

[0035] B: 0.08 kg of gelatin was added to 8 kg of water and stirred to disperse. Then, 0.016 kg of lauric acid was dissolved in 0.16 kg of ethanol and added. Then, 0.0008 kg of p-toluenesulfonic acid was added and the temperature was raised to 75 ° C and stirred for reaction for 7 hours. After the reaction was completed, the temperature was lowered to 50 ° C, 0.015 kg of D-galacturonic acid was added and stirred to mix evenly. The pH was adjusted to 6.5. After stirring and reacting for 25 minutes, 0.7 kg of porous composite particles and 0.00015 kg of indoleacetic acid were added and mixed evenly. After naturally cooling to room temperature, the mixture was transferred to 4 ° C and refrigerated overnight to obtain a healing gel;

[0036] C: The polylactic acid film was cut into a rectangle with a length of 25 cm and a width of 5 cm, and then a healing gel with a width of 5 cm, a length of 5 cm and a thickness of about 3 mm was coated on one end to obtain a healing bandage.

[0037] Example 2: Preparation of Healing Bandage II

[0038] A: Dissolve 0.1 kg of mannitol in water to prepare a 20 wt% mannitol solution. Add 0.6 kg of nanohydroxyapatite to the mannitol solution, stir and disperse, refrigerate at 4°C overnight, then freeze-dry at -50°C for 24 hours, and grind through a 50-mesh sieve to obtain composite particles. Add the composite particles to 60°C water, slowly stir for 5 minutes, and naturally cool to room temperature. Then, filter and remove the filtrate to obtain porous composite particles for later use.

[0039] B: 0.06 kg of gelatin was added to 6 kg of water and stirred to disperse. Then, 0.012 kg of lauric acid was dissolved in 0.12 kg of ethanol and added. Then, 0.0006 kg of p-toluenesulfonic acid was added and the temperature was raised to 70 ° C and stirred for reaction for 8 hours. After the reaction was completed, the temperature was lowered to 50 ° C, 0.01 kg of D-galacturonic acid was added and stirred to mix evenly. The pH was adjusted to 6.5. After stirring and reacting for 20 minutes, 0.6 kg of porous composite particles and 0.0001 kg of indoleacetic acid were added and mixed evenly. After naturally cooling to room temperature, the mixture was transferred to 4 ° C and refrigerated overnight to obtain a healing gel;

[0040] C: The polylactic acid film was cut into a rectangle with a length of 20 cm and a width of 4 cm, and then a healing gel with a width of 4 cm, a length of 5 cm and a thickness of about 3 mm was coated on one end to obtain a healing bandage.

[0041] Example 3: Preparation of Healing Bandage

[0042] A: Dissolve 0.2 kg of mannitol in water to prepare a 20 wt% mannitol solution. Add 1 kg of nanohydroxyapatite to the mannitol solution, stir and disperse, refrigerate at 4°C overnight, then freeze-dry at -50°C for 24 hours, and grind through a 50-mesh sieve to obtain composite particles. Add the composite particles to 60°C water, slowly stir for 5 minutes, and naturally cool to room temperature. Then, filter and remove the filtrate to obtain porous composite particles for later use.

[0043] B: 0.1 kg of gelatin was added to 10 kg of water and stirred to disperse. Then, 0.02 kg of lauric acid was dissolved in 0.2 kg of ethanol and added. Then, 0.001 kg of p-toluenesulfonic acid was added and the temperature was raised to 80°C and stirred for reaction for 6 hours. After the reaction was completed, the temperature was lowered to 50°C, 0.02 kg of D-galacturonic acid was added and stirred to mix evenly. The pH was adjusted to 6.5. After continuous stirring for 30 minutes, 1 kg of porous composite particles and 0.0002 kg of indoleacetic acid were added and mixed evenly. After naturally cooling to room temperature, the mixture was transferred to 4°C and refrigerated overnight to obtain a healing gel.

[0044] C: The polylactic acid film was cut into a rectangle with a length of 30 cm and a width of 6 cm, and then a healing gel with a width of 6 cm, a length of 5 cm and a thickness of about 3 mm was coated on one end to obtain a healing bandage.

[0045] Comparative Example 1: Preparation of Healing Bandage

[0046] In contrast to Example 1, the only difference is that in the preparation of the healing-promoting bandage in Comparative Example 1, mannitol is not added in step A to prepare the porous composite particles, but nano-hydroxyapatite is directly used, as shown below:

[0047] A: Add 0.08 kg of gelatin to 8 kg of water and stir to disperse. Then dissolve 0.016 kg of lauric acid in 0.16 kg of ethanol and add it. Then add 0.0008 kg of p-toluenesulfonic acid and heat to 75 ° C and stir to react for 7 hours. After the reaction is completed, cool to 50 ° C, add 0.015 kg of D-galacturonic acid and stir to mix evenly. Adjust the pH to 6.5. Continue stirring and reacting for 25 minutes. Then add 0.7 kg of nano-hydroxyapatite and 0.00015 kg of indoleacetic acid, mix evenly, and naturally cool to room temperature. Transfer to 4 ° C and refrigerate overnight to obtain a healing gel;

[0048] B: Same as step C in Example 1.

[0049] Comparative Example 2: Preparation of Healing Bandage

[0050] In contrast to Example 1, the only difference is that in the preparation of the healing-promoting bandage in Comparative Example 2, lauric acid is not added to treat the gelatin in Step B, as shown below:

[0051] A: Same as Example 1;

[0052] B: Add 0.08 kg of gelatin to 8 kg of water and stir to disperse. Heat to 75°C and stir to react for 7 hours. After the reaction is complete, cool to 50°C, add 0.015 kg of D-galacturonic acid and stir to mix evenly. Adjust the pH to 6.5. Continue stirring to react for 25 minutes. Then, add 0.7 kg of porous composite particles and 0.00015 kg of indoleacetic acid and mix evenly. After naturally cooling to room temperature, transfer to 4°C and refrigerate overnight to obtain a healing gel.

[0053] C: Same as Example 1.

[0054] Comparative Example 3: Preparation of Healing Bandage

[0055] In contrast to Example 1, the only difference is that in the preparation of the healing-promoting bandage in Comparative Example 3, D-galacturonic acid is not added in step B, as shown below:

[0056] A: Same as Example 1;

[0057] B: 0.08 kg of gelatin was added to 8 kg of water and stirred to disperse. Then, 0.016 kg of lauric acid was dissolved in 0.16 kg of ethanol and added. Then, 0.0008 kg of p-toluenesulfonic acid was added and the temperature was raised to 75 ° C and stirred for reaction for 7 hours. After the reaction was completed, the temperature was lowered to 50 ° C and the pH was adjusted to 6.5. Then, 0.7 kg of porous composite particles and 0.00015 kg of indoleacetic acid were added and mixed evenly. After naturally cooling to room temperature, the mixture was transferred to 4 ° C and refrigerated overnight to obtain a healing gel;

[0058] C: Same as Example 1.

[0059] Comparative Example 4: Preparation of Healing Bandage

[0060] In contrast to Example 1, the only difference is that the preparation of the healing-promoting bandage in Comparative Example 4 lacks step A, that is, porous composite particles are not added in step B, as shown below:

[0061] A: Add 0.08 kg of gelatin to 8 kg of water and stir to disperse. Then dissolve 0.016 kg of lauric acid in 0.16 kg of ethanol and add it. Then add 0.0008 kg of p-toluenesulfonic acid and heat to 75 ° C and stir to react for 7 hours. After the reaction is completed, cool to 50 ° C, add 0.015 kg of D-galacturonic acid and stir to mix evenly. Adjust the pH to 6.5, continue stirring and react for 25 minutes, add 0.00015 kg of indoleacetic acid and mix evenly. After cooling to room temperature, transfer to 4 ° C and refrigerate overnight to obtain a healing gel;

[0062] B: Same as step C in Example 1.

[0063] Comparative Example 5: Preparation of Healing Bandage

[0064] In contrast to Example 1, the only difference is that in step B of preparing the healing bandage in Comparative Example 5, the pH is adjusted to 6, and the remaining steps are the same as in Example 1.

[0065] Comparative Example 6: Preparation of Healing Bandage

[0066] In contrast to Example 1, the only difference is that in step B of preparing the healing-promoting bandage in Comparative Example 6, the pH is adjusted to 7, and the remaining steps are the same as in Example 1.

[0067] Example 4: Grafting method for persimmon

[0068] The zinc sulfate-copper sulfate mixture of this embodiment is prepared by mixing zinc sulfate and copper sulfate in a mass ratio of 1:2, weighing the mixture, and then adding 300 times the mass of water to dissolve the mixture;

[0069] (1) Scion collection and processing: In late December, one-year-old sweet persimmon branches with healthy growth, plump buds, and no pests and diseases were collected as scions. The collected scions were cut into 10 cm segments, with 2 to 4 buds retained in each segment. They were wrapped in wet cloth and stored at 4°C for use.

[0070] (2) Rootstock selection and treatment: In early April of the following year, select two-year-old wild persimmon seedlings that are healthy and free of pests and diseases as rootstocks. Cut the rootstock 20 cm from the ground, remove the side branches and buds on the rootstock trunk, flatten the cross section of the rootstock with a knife, and then cut vertically downward at the center of the cross section of the rootstock with a depth of 3 cm. Then, spray the cross section of the rootstock and the cut with a mixture of zinc sulfate and copper sulfate.

[0071] (3) Grafting: The preserved scion is taken out, and the lower end is cut into a 3 cm wedge shape, so that the length of the wedge surface is equivalent to the depth of the stock incision, and the scion cut surface is ensured to be smooth. The cut scion is inserted into the stock incision, so that the cambium of the scion and the stock are closely aligned, and then the grafting port is tightly bandaged with a healing gel-coated bandage prepared according to the method of Example 1. When bandaging, one end coated with the healing gelatin is first attached to the grafting port, and then the remaining part of the healing bandage is wrapped around the grafting port and tied tightly. After the bandage is completed, a hole is pricked in the bandage with a needle to obtain a grafted seedling;

[0072] (4) Transplantation and post-management: In mid-November, select healthy, disease-free, and fully budded grafted seedlings for transplanting. When transplanting, dig a planting hole first, place the grafted seedling in the planting hole and straighten it, then backfill the soil into the planting hole and tamp it down, and water it thoroughly. Later, carry out watering, fertilizing, pruning and other maintenance operations according to conventional methods.

[0073] Experiment: Grafting of sweet persimmons

[0074] A sweet persimmon grafting experiment was conducted in Liangshi Village, Hejiazhuang Town, Heyang County, Weinan City, Shaanxi Province. The experiment was divided into 12 groups: experimental group 1, control groups 1 to 10, and a blank control group. Each group used the following healing banding and grafting method:

[0075] Experimental Group 1: Using the healing-promoting bandage prepared in Example 1 and the grafting method of Example 4;

[0076] Control groups 1 to 6: using the healing-promoting bandages prepared in Comparative Examples 1 to 6 and the grafting method of Example 4, respectively;

[0077] Control group 7: The healing-promoting bandage prepared in Example 1 was used. The zinc sulfate-copper sulfate mixture used for grafting was weighed at a mass ratio of zinc sulfate:copper sulfate = 1:2 and then dissolved in 200 times the mass of water. The remaining steps were the same as those in Example 4.

[0078] Control group 8: The healing-promoting bandage prepared in Example 1 was used. The zinc sulfate-copper sulfate mixture used for grafting was weighed at a mass ratio of zinc sulfate:copper sulfate = 1:2 and then dissolved in 400 times the mass of water. The remaining steps were the same as those in Example 4.

[0079] Control group 9: The healing-promoting bandage prepared in Example 1 was used, but the zinc sulfate-copper sulfate mixture was not sprayed during grafting. The remaining steps were the same as those in Example 4.

[0080] Control group 10: Instead of using a healing bandage during grafting, conventional polylactic acid film was used for binding. The remaining steps were the same as those in Example 4.

[0081] Blank control group: No zinc sulfate-copper sulfate mixture was sprayed during grafting, no healing-promoting bandage was used for binding, but conventional polylactic acid film was used for binding. The remaining steps were the same as those in Example 4.

[0082] The rootstock used in the experiment was a 2-year-old wild persimmon with consistent growth conditions, and the scion used was Taiqiu branches collected from a 10-year-old healthy mother tree with consistent growth conditions.

[0083] Each group had 20 grafted plants. The grafting survival rate of each group was calculated 40 days after grafting. The grafted seedlings were transplanted and subsequently cared for in the same manner. Then, the plant height growth of each group was tested 6 months after transplanting. The experiment was repeated three times, and the average data were shown in Table 1.

[0084] Table 1

[0085]

[0086]

[0087] According to the data analysis in Table 1, we can see that:

[0088] (1) The grafting survival rate of sweet persimmons in experimental group 1 was 93.3%, and the plant height growth could reach 153.6 cm after 6 months of transplanting. This shows that the grafting cultivation of sweet persimmons according to the method of the present invention can effectively promote the healing of the grafting site, ensure the nutrient transfer between the rootstock and the scion, improve the grafting survival rate, and promote the good growth of the grafted seedlings.

[0089] (2) In the control group 1, mannitol was not added to prepare the porous composite particles during the preparation of the healing bandage. Instead, nanohydroxyapatite was directly used, which resulted in a decrease in the amount of calcium ions absorbed, affecting the healing and later growth of the grafting site. In the control group 4, porous composite particles were not added during the preparation of the healing bandage. The gel had poor air permeability and failed to provide calcium ions and copper ions for exchange, resulting in excessive production of reactive oxygen species, which seriously inhibited the healing of the grafting site.

[0090] (3) In the control group 3, D-galacturonic acid was not added during the preparation of the healing bandage, which reduced the adsorption performance of the healing gel on copper ions and affected the exchange reaction between calcium ions and copper ions. In the experimental group 1, D-galacturonic acid was added during the preparation of the healing gel, which adjusted the charge density of the healing gel, thereby enhancing the adsorption performance of the healing gel on copper ions and promoting the exchange reaction between calcium ions and copper ions. This was beneficial for preventing the production of excessive reactive oxygen species induced by long-term action of high concentrations of copper ions, and also promoted the absorption of calcium ions by the grafting site, thus better ensuring the healing of the grafting site.

[0091] (4) In the control group 2, lauric acid was not added to the gelatin during the preparation of the healing bandage. The excessive water content in the healing gel inhibited the healing of the grafting site, and the survival rate was reduced. In the control group 5, the pH of the healing gel was adjusted to 6 during the preparation of the healing bandage. In the control group 6, the pH of the healing gel was adjusted to 7 during the preparation of the healing bandage. Due to the change in pH, the activity of calcium ions and the exchange reaction with copper ions in the control groups 5 and 6 were inhibited, which affected the healing of the grafting site.

[0092] (4) In control group 7, the concentration of the zinc sulfate-copper sulfate mixture was too high during the grafting of sweet persimmons. Excessive copper ions induced the production of excessive reactive oxygen species, causing damage to plant cells and inhibiting the healing of the grafting site. The survival rate was low and the later growth condition was poor. In control group 8, the concentration of the zinc sulfate-copper sulfate mixture was too low, resulting in poor effect. In control group 9, the zinc sulfate-copper sulfate mixture was not sprayed, and the antibacterial and wound healing effects of zinc and copper ions were not exerted. The survival rate and later growth condition of the sweet persimmon grafting were significantly lower than those of experimental group 1. In control group 10, the copper sulfate-zinc sulfate solution was sprayed, but no healing bandage was tied. The long-term effect of the higher concentration of copper ions actually inhibited the healing of the wound. This shows that the zinc sulfate-copper sulfate mixture of the present invention must be combined with the healing gel in the healing bandage to play a good role in promoting the healing of the grafting site.

[0093] The above embodiments are intended only to illustrate the technical solutions of the present invention and are not intended to limit the scope of the present invention. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art will appreciate that the technical solutions of the present invention may be modified or replaced with equivalents without departing from the spirit and scope of the technical solutions of the present invention, and such modifications or equivalents shall be encompassed by the claims of the present invention. Any techniques, shapes, and structures not described in detail herein are well known.

Claims

1. A method for grafting sweet persimmons, characterized in that: The method comprises the following steps: (1) Scion collection and processing: From December to January of the following year, one-year-old sweet persimmon branches were collected as scions, cut into segments 8 to 15 cm long with 2 to 4 buds, wrapped in wet cloth and stored at 4°C until use; (2) Rootstock selection and treatment: From mid-March to early April, select 1-2 year old wild persimmon as the rootstock, cut the rootstock 15-30 cm from the ground, remove the side branches and buds, flatten the cross section of the rootstock, and then cut vertically downward from the center of the cross section of the rootstock with a depth of 2-3 cm. Then, spray the cross section and cut of the rootstock with a mixture of zinc sulfate and copper sulfate. (3) Grafting: After removing the scion, cut the lower end into a 2-3 cm wedge shape, insert the cut scion into the incision of the rootstock, align the cambium of the scion and the rootstock, and then bandage the grafting site with a healing bandage coated with healing gel. After bandaging, pierce the bandage to obtain a grafted seedling; (4) Transplantation and subsequent care: From November to December, dig the planting holes and transplant the grafted seedlings. Later, care can be carried out according to conventional methods.

2. The method for grafting sweet persimmon according to claim 1, wherein: The zinc sulfate-copper sulfate mixed solution in step (2) is obtained by mixing zinc sulfate and copper sulfate in a mass ratio of 1:2, weighing the mixture, and then adding the mixture into 300 times the mass of water to dissolve the mixture.

3. The grafting method for sweet persimmon according to claim 2, characterized in that: The preparation method of the healing-promoting bandage is as follows: A: Mannitol was dissolved in water to prepare a 20 wt% mannitol solution. Nanohydroxyapatite was added to the mannitol solution, stirred and dispersed, and then refrigerated at 4°C overnight. The mixture was then freeze-dried in a vacuum oven and ground and sieved to obtain composite microparticles. The composite microparticles were added to 60°C water and slowly stirred for 5 minutes. The mixture was then naturally cooled to room temperature. The filtrate was then filtered to obtain porous composite microparticles for later use. B: Gelatin was added to water and stirred to disperse, and lauric acid was dissolved in ethanol and added, followed by addition of p-toluenesulfonic acid. The temperature was raised to 70-80°C and stirred for reaction for 6-8 hours. After the reaction was completed, the temperature was lowered to 50°C, D-galacturonic acid was added, stirred and mixed, and the pH was adjusted to 6.

5. The reaction was continued with stirring for 20-30 minutes, and then the porous composite particles and indoleacetic acid were added, mixed and mixed, and then naturally cooled to room temperature. The mixture was transferred to 4°C and refrigerated overnight to obtain a healing gel. C: The polylactic acid film was cut into rectangles and then coated with healing gel to obtain a healing bandage.

4. The method for grafting sweet persimmon according to claim 3, wherein: The mass ratio of mannitol to nano-hydroxyapatite in step A is (0.1-0.2): (0.6-1).

5. The method for grafting sweet persimmon according to claim 4, characterized in that: The vacuum freeze-drying condition in step A is drying at -50°C for 24 hours.

6. The method for grafting sweet persimmon according to claim 5, characterized in that: In the preparation of the composite microparticles in step A, the composite microparticles are ground and then passed through a 50-mesh sieve.

7. The method for grafting sweet persimmon according to claim 6, characterized in that: In the step B, the mass ratio of gelatin, lauric acid, p-toluenesulfonic acid, D-galacturonic acid, porous composite particles and indoleacetic acid is (0.06-0.1): (0.012-0.02): (0.0006-0.001): (0.01-0.02): (0.6-1): (0.0001-0.0002).

8. The method for grafting sweet persimmon according to claim 7, characterized in that: In the step C, the polylactic acid film is cut into a rectangle with a length of 20 to 30 cm and a width of 4 to 6 cm.

9. The method for grafting sweet persimmon according to claim 8, characterized in that: The coating thickness of the healing gel in step C is 2 to 3 mm.

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