Method for distant grafting of pears and loquats

Abstract

The invention discloses a distant grafting method for pears and loquats, and belongs to the technical field of plant grafting planting. The method for distant grafting of pears and loquats comprises the following steps: grafting stocks and scions in a cleft grafting manner, spraying a healing accelerant, and then wrapping joints; when the rootstock is a pear tree, the scion is a loquat branch; when the stocks are loquat trees, the scions are pear tree branches; the healing accelerant is prepared from the following components in parts by mass: 10 to 12 parts of fructus hippophae extract, 6 to 7 parts of fructus aurantii immaturus extract, 0.1 to 0.3 part of brassin, 0.5 to 0.8 part of crab shell extract and 8 to 10 parts of chitosan. According to the method, the survival rate of distant grafting plants can be remarkably increased, excellent hybrids of distant grafting are expected to be obtained, and the method has important significance in fruit tree cultivation and breeding.

Description

Technical Field

[0001] The invention relates to the technical field of plant grafting and planting, in particular to a method for distant grafting of pears and loquats. Background Art

[0002] Grafting is one of the effective technologies for plant species innovation, rapid propagation of new varieties and rescue of damaged trees. Distant grafting refers to the grafting of different species, genera or species with more distant relationships in plant taxonomy, especially between plants of different families. According to the closeness of the relationship between the rootstock and the scion used for plant grafting, plant distant grafting can be divided into distant grafting between plant species, distant grafting between plant genera and distant grafting between plant families. Distant grafting of plants has always been a very attractive research topic. Through distant grafting, excellent characteristics that cannot be obtained by close or intraspecific hybridization, such as stress resistance, strong disease and insect resistance, and fast growth, can be obtained. In plant cultivation, it can improve the ornamental value, improve fruit quality, increase yield, and enhance plant resistance and adaptability; in breeding practice, it can overcome the incompatibility barriers of distant hybridization and cultivate distant grafted hybrids; it can also be used as an important means of plant genetics, plant physiology and molecular biology research.

[0003] However, the survival rate of distant grafting of plants is generally low, mainly because the genetic background of the rootstock and the scion is quite different, and the healing ability after grafting is low. In addition, after the graft survives, it usually grows weak, slow or deformed. Therefore, it is urgent to find a method that can improve the survival rate of distant grafting and the growth of distant grafted plants. Summary of the invention

[0004] The purpose of the present invention is to provide a method for distant grafting of pear and loquat to solve the problems existing in the above-mentioned prior art.

[0005] To achieve the above object, the present invention provides the following solutions:

[0006] One of the technical solutions of the present invention is a method for distant grafting of pear and loquat, comprising the following steps:

[0007] After the rootstock and scion are grafted by cleft grafting, a healing promoter is sprayed on them and then the interface is wrapped;

[0008] When the rootstock is a pear tree, the scion is a loquat branch; when the rootstock is a loquat tree, the scion is a pear branch;

[0009] The healing promoter comprises the following components in parts by weight: 10-12 parts of seabuckthorn extract, 6-7 parts of Citrus aurantium extract, 0.1-0.3 parts of brassinolide, 0.5-0.8 parts of crab shell extract and 8-10 parts of chitosan.

[0010] Furthermore, the preparation method of the seabuckthorn extract comprises the following steps:

[0011] After the sea buckthorn berries are crushed, high-temperature steam is introduced, and the steam condensed water and the crushed sea buckthorn berries are collected;

[0012] The crushed seabuckthorn fruit and steam condensed water are added into an ethanol solution, and heated for extraction to obtain an extract;

[0013] The extract is cooled and then centrifuged, and the supernatant is freeze-dried to obtain the seabuckthorn extract.

[0014] Furthermore, the temperature of the high-temperature steam is 105-115°C, and the introduction time is 20-30 minutes;

[0015] The concentration of the ethanol solution is 40-45 vol.%;

[0016] The usage ratio of seabuckthorn fruit and ethanol solution is 1g:10-15mL;

[0017] The heating extraction temperature is 80-100°C and the time is 1-2h;

[0018] The centrifugal speed is 10000-15000 rpm, and the time is 10 minutes.

[0019] Sea buckthorn extract is rich in amino acids and flavonoids. Amino acids can combine with proteins or phospholipids on the cell membrane to maintain the stability of the cell membrane and protect the grafted seedling cells. Flavonoids have antioxidant effects and can scavenge free radicals and reduce oxidative stress, thereby delaying cell aging, maintaining cell vitality at the grafting interface and improving the survival rate of the graft.

[0020] Furthermore, the preparation method of the Citrus aurantium extract comprises the following steps:

[0021] The immature tangerine peel is crushed and mixed with an ethanol solution, and then heated under reflux for extraction. The extract is concentrated and freeze-dried to obtain the immature tangerine peel extract.

[0022] Furthermore, the concentration of the ethanol solution is 70-80 vol.%;

[0023] The dosage ratio of the Citrus aurantium and the ethanol solution is 1g:8-10mL;

[0024] The temperature of the heating reflux extraction is 85-90° C. and the time is 3-4 hours.

[0025] Citrus aurantium extract can react with bacterial cell membrane or cell wall, degrade the bacterial cell wall structure, increase the permeability of the bacterial cell membrane, cause the macromolecular contents in the cell to seep out of the cell, weaken the motility of protons, and ultimately cause the bacteria to become inactivated and die, thereby avoiding the grafting interface from being infected by pathogens, causing the wound to become infected, and then causing the grafting interface to rot or even the inability of the grafted plant to survive.

[0026] Furthermore, the preparation method of the crab shell extract comprises the following steps:

[0027] The crab shells are crushed and then added with hydrochloric acid solution, stirred for reaction and then filtered to obtain decalcified crab shell powder;

[0028] Water is added to the decalcified crab shell powder to adjust the pH to 6.5-7, an enzymolysis agent is added, the enzyme is inactivated after the enzymolysis reaction, the solid and liquid are separated, and the product is dried to obtain the crab shell extract.

[0029] Further, the concentration of the hydrochloric acid solution is 2 to 3 wt.%;

[0030] The crab shell and hydrochloric acid solution are used in a ratio of 1 g: 7-9 mL;

[0031] The stirring reaction is carried out at a speed of 200 to 300 rpm and a time of 1 to 2 hours;

[0032] The dosage of the enzymolyzing agent is 0.01-0.02% of the crab shell mass;

[0033] The temperature of the enzymatic hydrolysis reaction is 35-45°C and the time is 2-3h;

[0034] The enzymolysis agent comprises the following components in parts by weight: 10 to 12 parts of deacetylase, 2 to 3 parts of cellulase, 2 to 3 parts of hemicellulase and 3 to 6 parts of lipase.

[0035] Crab shell extract is rich in chitosan oligosaccharides, which work synergistically with brassinolide to promote the formation of callus tissue and improve the grafting survival rate.

[0036] The chitosan in the healing promoter can form a protective film at the incision site, preventing bacteria from invading the incision, preventing the loss of water and nutrients, and improving the survival rate of the graft.

[0037] The seabuckthorn extract, citrus aurantium extract, brassinolide, crab shell extract and chitosan in the healing promoter work synergistically to protect cell activity while improving cell viability, promote the formation of callus tissue, avoid pathogen infection and loss of water and nutrients, and thus improve the grafting survival rate. It can also make the grafting interface heal better and improve the growth of the grafted plant.

[0038] Furthermore, the method for distant grafting of pear and loquat also includes applying a water retaining agent after spraying the healing promoter and before wrapping the interface.

[0039] Furthermore, the preparation method of the water-retaining agent comprises the following steps:

[0040] After polyvinyl alcohol is dissolved in water, persulfate is added and mixed evenly, and then sodium alginate and aluminum chloride are added, heated for reaction, and cooled to obtain the water retaining agent.

[0041] Furthermore, the mass ratio of the polyvinyl alcohol, persulfate, sodium alginate and aluminum chloride is 1:0.5:0.1:0.1;

[0042] The temperature of the heating reaction is 80-90° C. and the time is 1-1.5 hours.

[0043] Water-retaining agents can promote the rapid healing of grafted interfaces and have a certain degree of air permeability. While providing moisture to grafted plants, they can also avoid the problem of grafted interface rot caused by airtightness, and can significantly improve the survival rate of plant grafting.

[0044] The present invention discloses the following technical effects:

[0045] (1) The method of the present invention can significantly improve the survival rate of distantly grafted plants, and is expected to obtain excellent hybrids of distantly grafted plants, which is of great significance in fruit tree cultivation and breeding.

[0046] (2) The method of the present invention can overcome the problems of weak growth, slow growth or deformity of distantly grafted plants, and can obtain strong and well-growing grafted plants. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0048] Figure 1 The growth conditions of the pear rootstock and loquat scion after grafting in Example 1, wherein A is 1 month after grafting, B is 2 months after grafting, C is 3 months after grafting, D is 6 months after grafting, E is 10 months after grafting, F is 15 months after grafting, and G is 18 months after grafting.

[0049] Figure 2 The graph shows the growth of the loquat tree rootstock and the pear tree scion after grafting in Example 3, wherein A is the day of grafting, B is 1 month after grafting, C is 3 months after grafting, and D is 6 months after grafting. DETAILED DESCRIPTION

[0050] Various exemplary embodiments of the present invention will now be described in detail. This detailed description should not be considered as limiting the present invention, but should be understood as a more detailed description of certain aspects, features, and embodiments of the present invention.

[0051] It should be understood that the terms described in the present invention are only for describing special embodiments and are not intended to limit the present invention. In addition, for the numerical range in the present invention, it should be understood that each intermediate value between the upper and lower limits of the scope is also specifically disclosed. Each smaller range between the intermediate value in any stated value or stated range and any other stated value or intermediate value in the described range is also included in the present invention. The upper and lower limits of these smaller ranges can be independently included or excluded in the scope.

[0052] Unless otherwise indicated, all technical and scientific terms used herein have the same meanings as those generally understood by those skilled in the art. Although the present invention describes only preferred methods and materials, any methods and materials similar or equivalent to those described herein may also be used in the implementation 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 a conflict with any incorporated document, the content of this specification shall prevail.

[0053] It will be apparent to those skilled in the art that various modifications and variations may be made to the specific embodiments of the present invention description without departing from the scope or spirit of the present invention. Other embodiments derived from the present invention description will be apparent to the skilled artisan. The present invention description and examples are exemplary only.

[0054] The words “include,” “including,” “have,” “contain,” etc. used in this document are open-ended terms, meaning including but not limited to.

[0055] Pear belongs to the genus Pyrus of the subfamily Amygdaloideae of the family Rosaceae. It is a deciduous tree or shrub. my country is one of the three major origin centers of pear, with a cultivation history of more than 3,000 years. At present, there are thousands of pear varieties, mainly divided into two major groups: European pear and Asian pear. Most pear varieties are diploid (2n=34). The genus Pyrus contains at least 22 basic species with clear classification, but only a few species such as white pear (Pyrus bretschneideri), sand pear (P.pyrifolia), autumn pear (P.ussuriensis), Xinjiang pear (P.sinkiangensis) and Western pear (P.communis) are used for pear production. Pear is one of the main fruit tree varieties in my country, and the cultivated area and output are among the highest in the world.

[0056] Loquat belongs to the genus Eriobotrya of the subfamily Amygdaloideae of the family Rosaceae. It is an evergreen fruit tree with delicious fruit and great nutritional and medicinal value. Loquat also originated in China and was cultivated as early as the Han Dynasty more than 2,000 years ago. At present, it is planted in more than 30 countries around the world, including China, Japan, the United States, France, Italy, Egypt and Spain. Most loquats are diploid (2n=34), containing about 26 species, and are mainly divided into two major groups of white flesh and yellow flesh according to the color of their flesh and peel. Loquat is also an important medicinal plant. Its roots, leaves and flowers have long been used to treat diabetes, cancer, bacterial infections, aging, pain and allergies.

[0057] Pear and loquat belong to the same family but different genera, and one is a deciduous fruit tree and the other is an evergreen fruit tree, so they are relatively distantly related. Grafting the two is called inter-generic grafting, which is a form of distant grafting and a difficult problem in plant grafting. There are also records of inter-family grafting in the "Tree Planting Book" by Yu Zongben of the Ming Dynasty, such as: "Plum grafted with peach is crisp, peach grafted with apricot is big" (inter-specific grafting), "Citrus and orange are easy to survive if they are grafted with root thorns" (inter-generic grafting), "Plum grafted on mulberry will not be sour" (inter-family grafting), etc. At present, there have been some successful reports of inter-family distant grafting in China, such as the use of distant grafting of sweet potato and wheat to cultivate new varieties such as "potato wheat", which shows that distant grafting can improve crop varieties and improve crop quality. However, at present, the survival rate of distant grafting is not very ideal.

[0058] Successful distant grafting of pear and loquat may improve the ability of the pear scion to continue growing after leaf fall, increase yield and improve fruit quality. It may also improve the fruit quality of the loquat scion and cultivate new distant grafted hybrid varieties.

[0059] The “parts” described in the following examples are all “parts by mass”.

[0060] The distant grafting experiments in the following embodiments and comparative examples of the present invention were all conducted at the Pear Experimental Demonstration Base of the Fruit Research Institute of Jiangsu Academy of Agricultural Sciences (118°51′0″ east longitude, 32°2′14″ north latitude), which is located in the middle and lower reaches of the Yangtze River and has a northern subtropical humid climate. The average annual precipitation is 1106.5 mm, the highest temperature is 42.7°C, the lowest is -13.1°C, and the average annual temperature is 15.4°C.

[0061] Example 1

[0062] A method for distant grafting of pear and loquat:

[0063] (1) A healing promoter, comprising the following components in parts by weight: 12 g of seabuckthorn extract, 6 g of Citrus aurantium extract, 0.2 g of brassinolide, 0.8 g of crab shell extract and 9 g of chitosan (molecular weight of 50,000 to 100,000).

[0064] A. Preparation of Seabuckthorn Extract:

[0065] Fresh sea buckthorn fruit was crushed with a crusher and then introduced with high temperature steam (the temperature of the high temperature steam was 110°C and the introduction time was 30 minutes), and the steam condensed water and the crushed sea buckthorn fruit were collected;

[0066] The crushed seabuckthorn fruit and steam condensed water were added to an ethanol aqueous solution with a concentration of 45 vol.% (the amount ratio of seabuckthorn fruit to ethanol aqueous solution was 1 g: 12 mL), and heated for extraction (temperature was 90°C, time was 1.5 h), to obtain an extract;

[0067] The extract was cooled and then centrifuged (rotation speed was 15000 rpm, time was 10 min), and the supernatant was freeze-dried (-30° C.) to obtain the seabuckthorn extract.

[0068] B. Preparation of Citrus aurantium extract:

[0069] The Citrus aurantium was dried and crushed to 100 mesh to obtain Citrus aurantium powder, which was mixed with 70-80 vol.% ethanol aqueous solution (the dosage ratio of Citrus aurantium powder to ethanol aqueous solution was 1 g: 10 mL), and the mixture was heated to reflux for extraction (temperature was 90°C, time was 3 h), and the extract was concentrated and freeze-dried (-30°C) to obtain the Citrus aurantium extract.

[0070] C. Preparation of crab shell extract:

[0071] The crab shells were crushed into 100 meshes, and then a 3wt.% hydrochloric acid aqueous solution was added (the ratio of crab shells to hydrochloric acid aqueous solution was 1g:8mL), stirred for reaction (rotation speed was 250rpm, time was 2h), filtered, washed with water, and dried to obtain decalcified crab shell powder;

[0072] Add water to the decalcified crab shell powder (the ratio of decalcified crab shell powder to water is 1 g: 20 mL), adjust the pH to 7, add an enzymatic agent (the amount is 0.02% of the crab shell mass), carry out enzymatic reaction (the temperature of the enzymatic reaction is 40° C. and the time is 2 h), then inactivate the enzyme (heat to 110° C. and maintain for 20 min), separate the solid and liquid, and dry to obtain a crab shell extract.

[0073] The enzymolytic agent is composed of the following components in parts by weight: 12 parts of deacetylase, 3 parts of cellulase, 2.5 parts of hemicellulase and 4 parts of lipase.

[0074] (2) One-year-old branches from the trunk of an 8-year-old pear tree (Cui Guan) were used as rootstocks (about 90-120 cm above the ground), and one-year-old branches of loquat (Guan Yu) were used as scions. The grafting was performed by cleft grafting before the budding of the pear tree (early March). The scion was about 2.5 cm long, with one bud point retained. It was cut into a wedge shape with a length of about 1 cm, which was equivalent to the length of the rootstock cut, and the outer side was slightly thicker than the inner side. The cleft of the rootstock was pried open and the scion was aligned with the cambium of the rootstock. One loquat scion was grafted on each pear tree, and 50 trees were grafted.

[0075] Dissolve the healing promoter (12 g of seabuckthorn extract, 6 g of Citrus aurantium extract, 0.2 g of brassinolide, 0.8 g of crab shell extract and 9 g of chitosan (molecular weight of 50,000 to 100,000)) in water and adjust the volume to 1 L to obtain a healing promoter solution;

[0076] Spray the healing promoter solution on the grafting interface until the solution flows down the trunk, then tie the grafting interface tightly with gauze. Untie it 5 months after grafting.

[0077] Example 2

[0078] A method for distant grafting of pear and loquat:

[0079] (1) A healing promoter, comprising the following components in parts by weight: 10 g of seabuckthorn extract, 7 g of Citrus aurantium extract, 0.3 g of brassinolide, 0.5 g of crab shell extract and 10 g of chitosan (molecular weight of 50,000 to 100,000).

[0080] A. Preparation of Seabuckthorn Extract:

[0081] Fresh sea buckthorn fruit was crushed with a crusher and then introduced with high temperature steam (the temperature of the high temperature steam was 105°C and the introduction time was 20 minutes), and the steam condensed water and the crushed sea buckthorn fruit were collected;

[0082] The crushed seabuckthorn fruit and steam condensed water are added to a 40 vol.% ethanol aqueous solution (the ratio of seabuckthorn fruit to ethanol aqueous solution is 1 g: 10 mL), and heated for extraction (temperature is 100° C., time is 1 to 1 h), to obtain an extract;

[0083] The extract was cooled and then centrifuged (rotation speed was 15000 rpm, time was 10 min), and the supernatant was freeze-dried (-30° C.) to obtain the seabuckthorn extract.

[0084] B. Preparation of Citrus aurantium extract:

[0085] The Citrus aurantium was dried and crushed to 100 mesh to obtain Citrus aurantium powder, which was mixed with 70-80 vol.% ethanol aqueous solution (the dosage ratio of Citrus aurantium powder to ethanol aqueous solution was 1 g: 8 mL), and the mixture was heated to reflux for extraction (temperature was 85°C, time was 4 h), and the extract was concentrated and freeze-dried (-30°C) to obtain the Citrus aurantium extract.

[0086] C. Preparation of crab shell extract:

[0087] The crab shells were crushed into 100 meshes, and then a 2 wt.% hydrochloric acid aqueous solution was added (the ratio of the crab shells to the hydrochloric acid aqueous solution was 1 g: 9 mL), stirred for reaction (rotation speed was 300 rpm, time was 1.5 h), and then filtered, washed with water, and dried to obtain decalcified crab shell powder;

[0088] Add water to the decalcified crab shell powder (the ratio of decalcified crab shell powder to water is 1 g: 20 mL), adjust the pH to 6.5, add an enzymatic agent (the amount is 0.01% of the crab shell mass), carry out enzymatic reaction (the temperature of the enzymatic reaction is 35° C., and the time is 3 h), then inactivate the enzyme (heat to 110° C., maintain for 20 min), separate the solid and liquid, and dry to obtain a crab shell extract.

[0089] The enzymolytic agent is composed of the following components in parts by weight: 10 parts of deacetylase, 2 parts of cellulase, 3 parts of hemicellulase and 6 parts of lipase.

[0090] (2) One-year-old branches from the trunk of an 8-year-old pear tree (Cuiguan variety) were used as rootstocks (about 90-120 cm above the ground), and one-year-old branches of loquat (Guanyu variety) were used as scions. The grafting was performed by cleft grafting before the budding of the pear tree (early March). The scion was about 2.5 cm long, with one bud point retained, cut into a wedge shape, and the cut surface was about 1 cm long, which was equivalent to the length of the rootstock cut, and the outer side was slightly thicker than the inner side. The cleft of the rootstock was pried open, and the scion was aligned with the cambium of the rootstock. One loquat scion was grafted on each pear tree, and 50 trees were grafted.

[0091] Dissolve the healing promoter (10 g of seabuckthorn extract, 7 g of Citrus aurantium extract, 0.3 g of brassinolide, 0.5 g of crab shell extract and 10 g of chitosan (molecular weight of 50,000 to 100,000)) in water and adjust the volume to 1 L to obtain a healing promoter solution;

[0092] Spray the healing promoter solution on the grafting interface until the solution flows down the trunk, then tie the grafting interface tightly with gauze. Untie it 5 months after grafting.

[0093] Example 3

[0094] The same as Example 1, except that step (2) is specifically as follows:

[0095] The trunk of a two-year-old loquat tree (variety Guanyu) was used as the rootstock (the cross-section of the trunk was 40 cm from the ground), and the one-year-old branches of a pear (variety Cuiguan) were used as scions. The grafting was performed by cleft grafting before the pear trees sprouted (early March) (the scion was about 2.5 cm long, with one bud point retained, and was cut into a wedge shape with a cut surface of about 1 cm long, which was equivalent to the length of the rootstock incision, and the outer side was slightly thicker than the inner side. The cleft of the rootstock was pried open, and the scion was aligned with the cambium of the rootstock). One pear scion was grafted on each loquat tree, and 50 trees were grafted.

[0096] Dissolve the healing promoter (12 g of seabuckthorn extract, 6 g of Citrus aurantium extract, 0.2 g of brassinolide, 0.8 g of crab shell extract and 9 g of chitosan (molecular weight of 50,000 to 100,000)) in water and adjust the volume to 1 L to obtain a healing promoter solution;

[0097] Spray the healing promoter solution on the grafting interface until the solution flows down the trunk, then tie the grafting interface tightly with gauze. Untie it 5 months after grafting.

[0098] Example 4

[0099] A method for distant grafting of pear and loquat:

[0100] (1) Same as Example 1.

[0101] (2) One-year-old branches from the trunk of an 8-year-old pear tree (Cui Guan) were used as rootstocks (about 90-120 cm above the ground), and one-year-old branches of loquat (Guan Yu) were used as scions. The grafting was performed by cleft grafting before the budding of the pear tree (early March). The scion was about 2.5 cm long, with one bud point retained. It was cut into a wedge shape with a length of about 1 cm, which was equivalent to the length of the rootstock cut, and the outer side was slightly thicker than the inner side. The cleft of the rootstock was pried open and the scion was aligned with the cambium of the rootstock. One loquat scion was grafted on each pear tree, and 50 trees were grafted.

[0102] Dissolve the healing promoter (12 g of seabuckthorn extract, 6 g of Citrus aurantium extract, 0.2 g of brassinolide, 0.8 g of crab shell extract and 9 g of chitosan (molecular weight of 50,000 to 100,000)) in water and adjust the volume to 1 L to obtain a healing promoter solution;

[0103] Spray the healing promoter solution on the grafting interface until the solution flows down the trunk, then apply 10g of water retaining agent on the grafting interface, let it stand for 5 minutes, and then tie the grafting interface firmly with gauze. Untie it after 5 months of grafting.

[0104] The preparation method of the water retaining agent is as follows: polyvinyl alcohol (weight average molecular weight is 20000) is dissolved in water (the mass ratio of polyvinyl alcohol to water is 15:100), persulfate (potassium persulfate) is added and mixed evenly, and then sodium alginate and aluminum chloride are added (the mass ratio of polyvinyl alcohol, persulfate, sodium alginate and aluminum chloride is 1:0.5:0.1:0.1), heated to react (temperature 90°C, time 1.5h), and the water retaining agent is obtained after cooling.

[0105] Example 5

[0106] A method for distant grafting of pear and loquat:

[0107] (1) Same as Example 3.

[0108] (2) The trunk of a two-year-old loquat tree (variety Guanyu) was used as the rootstock (the cross section of the trunk was 40 cm from the ground), and the one-year-old branches of a pear (variety Cuiguan) were used as the scion. The grafting was performed by cleft grafting before the pear tree sprouted (early March) (the scion was about 2.5 cm long, with one bud point retained, and was cut into a wedge shape with a length of about 1 cm, which was equivalent to the length of the rootstock cut, and the outer side was slightly thicker than the inner side. The cleft of the rootstock was pried open and the scion was aligned with the cambium of the rootstock). One pear scion was grafted on each loquat tree, and 50 trees were grafted.

[0109] Dissolve the healing promoter (12 g of seabuckthorn extract, 6 g of Citrus aurantium extract, 0.2 g of brassinolide, 0.8 g of crab shell extract and 9 g of chitosan (molecular weight of 50,000 to 100,000)) in water and adjust the volume to 1 L to obtain a healing promoter solution;

[0110] Spray the healing promoter solution on the grafting interface until the solution flows down the trunk, then apply 10g of water retaining agent on the grafting interface, let it stand for 5 minutes, and then tie the grafting interface firmly with gauze. Untie it after 5 months of grafting.

[0111] The preparation method of the water retaining agent is as follows: polyvinyl alcohol (weight average molecular weight is 20000) is dissolved in water (the mass ratio of polyvinyl alcohol to water is 15:100), persulfate (potassium persulfate) is added and mixed evenly, and then sodium alginate and aluminum chloride are added (the mass ratio of polyvinyl alcohol, persulfate, sodium alginate and aluminum chloride is 1:0.5:0.1:0.1), heated to react (temperature 90°C, time 1.5h), and the water retaining agent is obtained after cooling.

[0112] Comparative Example 1

[0113] Same as Example 1, except that the healing promoter solution was not sprayed during grafting.

[0114] Comparative Example 2

[0115] Same as Example 3, except that the healing promoter solution was not sprayed during grafting.

[0116] Comparative Example 3

[0117] Same as Example 1, except that the crab shell extract in the healing promoter is replaced with an equal mass of brassinolide.

[0118] Comparative Example 4

[0119] The same as Example 1, except that the brassinolide in the healing promoter is replaced with salicylic acid of equal mass.

[0120] Comparative Example 5

[0121] Same as Example 1, except that the healing promoter does not contain seabuckthorn extract and immature bitter orange extract.

[0122] Comparative Example 6

[0123] The same as Example 1, except that the seabuckthorn extract is prepared by crushing fresh seabuckthorn fruit with a grinder and adding it to a 45 vol.% ethanol aqueous solution (the ratio of seabuckthorn fruit to ethanol aqueous solution is 1 g: 12 mL), and heating extraction (temperature is 90° C., time is 1.5 h) to obtain an extract;

[0124] The extract was cooled and then centrifuged (rotation speed was 15000 rpm, time was 10 min), and the supernatant was freeze-dried (-30° C.) to obtain the seabuckthorn extract.

[0125] Effect Example 1

[0126] The growth of the pear rootstock and loquat scion grafted in Example 1 was observed. Figure 1 , Figure 1 In the figure, A is 1 month after grafting, B is 2 months after grafting, C is 3 months after grafting, D is 6 months after grafting, E is 10 months after grafting, F is 15 months after grafting, and G is 18 months after grafting. The ruler in Figure G is 10 cm.

[0127] The growth of loquat rootstock and pear scion grafted in Example 3 was observed. Figure 2 , Figure 2 In the figure, A is the day of grafting, B is 1 month after grafting, C is 3 months after grafting, and D is 6 months after grafting. The ruler in Figure D is 10 cm.

[0128] One year after grafting, the grafting survival rate was calculated and the growth condition was investigated. The results are shown in Table 1.

[0129] Table 1 Grafting survival rate and growth

[0130]

[0131] The grafting survival rate of the method of the present invention is high, the tree grows fast, no incompatibility phenomenon occurs within 2 years of grafting, and the tree can safely overwinter.

[0132] The embodiments described above are only descriptions of the preferred modes of the present invention, and are not intended to limit the scope of the present invention. Without departing from the design spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by ordinary technicians in this field should all fall within the protection scope determined by the claims of the present invention.

Claims

1. A method for distant grafting of pear and loquat, characterized in that: The following steps are involved: After the rootstock and scion are grafted by cleft grafting, a healing promoter is sprayed on them and then the interface is wrapped; When the rootstock is a pear tree, the scion is a loquat branch; when the rootstock is a loquat tree, the scion is a pear branch; The healing promoter comprises the following components in parts by weight: 10-12 parts of seabuckthorn extract, 6-7 parts of Citrus aurantium extract, 0.1-0.3 parts of brassinolide, 0.5-0.8 parts of crab shell extract and 8-10 parts of chitosan.

2. The method according to claim 1, characterized in that: The preparation method of the seabuckthorn extract comprises the following steps: After the sea buckthorn berries are crushed, high-temperature steam is introduced, and the steam condensed water and the crushed sea buckthorn berries are collected; The crushed seabuckthorn fruit and steam condensed water are added into an ethanol solution, and heated for extraction to obtain an extract; The extract is cooled and then centrifuged, and the supernatant is freeze-dried to obtain the seabuckthorn extract.

3. The method according to claim 2, characterized in that The temperature of the high-temperature steam is 105-115°C, and the introduction time is 20-30 minutes; and / or, the concentration of the ethanol solution is 40-45 vol.%; And / or, the usage ratio of the seabuckthorn fruit and the ethanol solution is 1 g: 10-15 mL; And / or, the temperature of the heating extraction is 80-100°C and the time is 1-2h; And / or, the centrifugal rotation speed is 10000-15000 rpm, and the time is 10 min.

4. The method according to claim 1, characterized in that The preparation method of the Citrus aurantium extract comprises the following steps: The immature tangerine peel is crushed and mixed with an ethanol solution, and then heated under reflux for extraction. The extract is concentrated and freeze-dried to obtain the immature tangerine peel extract.

5. The method according to claim 4, characterized in that The concentration of the ethanol solution is 70-80 vol.%; And / or, the dosage ratio of the Citrus aurantium and the ethanol solution is 1 g: 8-10 mL; And / or, the temperature of the heating reflux extraction is 85-90° C. and the time is 3-4 hours.

6. The method according to claim 1, characterized in that The preparation method of the crab shell extract comprises the following steps: The crab shells are crushed and then added with hydrochloric acid solution, stirred for reaction and then filtered to obtain decalcified crab shell powder; Water is added to the decalcified crab shell powder to adjust the pH to 6.5-7, an enzymolysis agent is added, the enzyme is inactivated after the enzymolysis reaction, the solid and liquid are separated, and the product is dried to obtain the crab shell extract.

7. The method according to claim 6, characterized in that The concentration of the hydrochloric acid solution is 2-3 wt.%; And / or, the crab shell and the hydrochloric acid solution are used in a ratio of 1 g: 7-9 mL; And / or, the stirring reaction is carried out at a speed of 200 to 300 rpm for 1 to 2 hours; And / or, the amount of the enzymolytic agent is 0.01-0.02% of the crab shell mass; And / or, the temperature of the enzymatic hydrolysis reaction is 35-45° C., and the time is 2-3 hours.

8. The method according to claim 1, characterized in that: It also includes applying a moisture retaining agent after spraying the healing promoter and before wrapping the interface.

9. The method according to claim 8, characterized in that The preparation method of the water-retaining agent comprises the following steps: After polyvinyl alcohol is dissolved in water, persulfate is added and mixed evenly, and then sodium alginate and aluminum chloride are added, heated for reaction, and cooled to obtain the water retaining agent.

10. The method according to claim 9, characterized in that The mass ratio of the polyvinyl alcohol, persulfate, sodium alginate and aluminum chloride is 1:0.5:0.1:0.1; And / or, the heating reaction temperature is 80-90° C. and the time is 1-1.5 h.

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