A method for growing strong seedlings of grafted seedlings of ancient trees of acer rubrum

Abstract

The present application relates to the technical field of seedling breeding, and provides a strong seedling breeding method for red-cone ancient tree grafted seedlings, which comprises the following steps: (1) applying fertilizer A to the mother plant for 6 months before grafting; (2) grafting the stock and the pretreated scion by cutting grafting, smearing healing-promoting liquid on the grafting interface, and binding; (3) applying fertilizer B at the fifth week after grafting; and (4) applying fertilizer C every 15 days from the third month after grafting to the time of transplanting. The healing-promoting liquid and the binding operation can effectively promote the healing of the grafting interface and improve the grafting survival rate. According to the nutrient requirement of the red-cone grafted seedlings at different growth stages, the present application effectively promotes the growth of the red-cone grafted seedlings, promotes the lateral root development, and increases the number of roots, which provides sufficient material guarantee for the healthy growth of the seedlings and technical support for the protection and large-scale breeding of the red-cone ancient tree resources.

Description

Technical Field

[0001] This invention relates to the field of seedling propagation technology, and in particular to a method for propagating robust seedlings of grafted ancient Conifer spp. Background Technology

[0002] The Chinese pine (Castanopsis chinensis) is a large evergreen tree belonging to the genus Castanopsis in the family Fagaceae. Its wood is hard and has a beautiful grain, possessing value in timber, ecology, and economy. Especially ancient Chinese pine trees, especially those of considerable age, are not only important forestry resources but also have extremely high scientific research and ecological conservation value. However, traditional methods for propagating grafted seedlings of ancient Chinese pine trees face several technical bottlenecks: on the one hand, the graft union heals slowly, making it susceptible to pathogen infection or external environmental influences, resulting in a generally low grafting survival rate; on the other hand, post-grafting fertilization management lacks specificity, either leading to improper fertilizer ratios causing excessive vegetative growth or nutrient imbalances, or incorrect fertilization timing affecting lateral root development, ultimately resulting in weak grafted seedlings with poor resistance, failing to meet the standards for robust seedlings.

[0003] In existing technologies, interface treatment often uses a single wax seal or ordinary plastic film wrapping, which cannot simultaneously meet the needs of moisturizing, antibacterial and callus formation; fertilization management often follows the conventional fertilization mode for seedlings, without considering the special nutrient requirements of grafted seedlings of ancient red pine trees at different growth stages, resulting in slow seedling growth, few lateral roots, and failure to achieve the goal of cultivating strong seedlings.

[0004] Therefore, developing a method for propagating robust seedlings of ancient red pine trees that can effectively promote interface healing and accurately meet the nutrient needs of grafted seedlings has become an urgent problem to be solved in the field of forestry propagation. Summary of the Invention

[0005] The purpose of this invention is to provide a method for propagating robust seedlings of grafted ancient Chinese pine trees. By optimizing interface treatment and fertilization management, the survival rate and growth quality of grafted ancient Chinese pine trees can be improved, thus solving problems such as low survival rate and weak growth in the propagation of grafted ancient Chinese pine trees.

[0006] To achieve the above-mentioned objectives, the present invention provides the following technical solution:

[0007] This invention provides a method for propagating robust seedlings of ancient Conifer fraseri grafted onto grafted seedlings, comprising the following steps:

[0008] (1) Apply fertilizer A to the mother plant for grafting 6 months before grafting;

[0009] (2) The rootstock and the pretreated scion are grafted by cleft grafting, and a healing agent is applied to the graft union and then bound.

[0010] (3) Apply fertilizer B in the 5th week after grafting;

[0011] (4) Apply fertilizer C every 15 days from the third month after grafting until the plant is ready for transplanting.

[0012] Preferably, fertilizer A in step (1) is organic fertilizer and superphosphate fertilizer in a mass ratio of (300-400):(25-35).

[0013] Preferably, the organic fertilizer in step (1) has an effective live bacteria count ≥ 268 million / g and an organic matter content ≥ 59%; the superphosphate fertilizer has an effective P2O5 content ≥ 12.0%.

[0014] Preferably, the amount of fertilizer A applied in step (1) is 60-80 kg / mu, and the number of fertilizations is 1-2 times.

[0015] As a preferred option, the pretreatment method in step (2) is to soak the lower 3-4 cm part of the scion in the soaking solution for 15-20 minutes.

[0016] Preferably, the soaking solution comprises: 10-15 parts glucose, 8-12 parts trehalose, 5-8 parts propylene glycol, 2-3 parts zinc thiazolyl, 0.3-0.6 parts indolebutyric acid, 0.3-0.5 parts vitamin C, and 900-1100 parts water.

[0017] Preferably, the healing-promoting solution comprises the following components in parts by weight: 0.8-1.2 parts naphthaleneacetic acid, 0.2-0.4 parts 6-benzylaminopurine, 0.3-0.7 parts brassinolide, 8-12 parts yeast extract, 5-8 parts potassium dihydrogen phosphate, 3-5 parts chitosan, 3-5 parts propylene glycol, and 900-1100 parts water.

[0018] Preferably, the binding method is as follows: a transparent polyethylene film, absorbent cotton soaked in 450-550 times carbendazim solution, and elastic plastic straps are used to wrap and cover the interface and the surrounding 2-3cm area.

[0019] Preferably, fertilizer B in step (3) is a nitrogen-phosphorus-potassium compound fertilizer.

[0020] Preferably, the mass ratio of N, P2O5, and K2O in the nitrogen-phosphorus-potassium compound fertilizer is (0.8-1.2):1:1.

[0021] Preferably, the amount of fertilizer B applied in step (3) is 80-100g / plant, and the number of fertilizations is 1-2 times.

[0022] Preferably, the fertilizer C in step (4) is urea and trace element fertilizer in a mass ratio of (1-3):(0.5-1).

[0023] Preferably, the micronutrient fertilizer is zinc fertilizer, boron fertilizer, iron fertilizer or magnesium fertilizer.

[0024] Preferably, the application rate of fertilizer C is 100-200g / plant.

[0025] By adopting the above technical solution, the present invention has the following beneficial effects:

[0026] 1. The technical solution of this invention uses soaking solution and healing-promoting solution to maintain the basic activity of the scion by moisturizing and replenishing nutrients, stimulating cell division and growth, effectively promoting the formation of callus tissue at the interface, and further improving the quality of interface healing; the addition of antibacterial components can inhibit the growth of pathogens, prevent interface infection, create a good environment for interface healing, and at the same time avoid grafting failure caused by the scion itself carrying bacteria, thereby improving the grafting success rate.

[0027] 2. The phased fertilization scheme of this invention can meet the nutrient requirements of different growth stages, provide sufficient nutrients, promote rapid seedling growth, and also promote the development of lateral roots in grafted Conifer saplings. Specifically, organic fertilizer improves soil structure, making the soil looser and more aerated, which is conducive to root growth and extension; nitrogen-phosphorus-potassium compound fertilizer provides the main nutrients such as nitrogen, phosphorus, and potassium; and trace element fertilizers containing zinc, boron, iron, and other elements play a crucial role in root growth and development. Detailed Implementation

[0028] This invention provides a method for propagating robust seedlings of ancient Conifer fraseri grafted onto grafted seedlings, comprising the following steps:

[0029] (1) Apply fertilizer A to the mother plant for grafting 6 months before grafting;

[0030] (2) The rootstock and the pretreated scion are grafted by cleft grafting, and a healing agent is applied to the graft union and then bound.

[0031] (3) Apply fertilizer B in the 5th week after grafting;

[0032] (4) Apply fertilizer C every 15 days from the third month after grafting until the plant is ready for transplanting.

[0033] In this invention, robust, disease-free, and 2-3 year old Conifer seedlings are preferably selected as rootstocks. Such rootstocks have well-developed root systems, which can provide sufficient nutrients and water to the scion, ensuring the subsequent growth of the grafted seedling; they also have strong vitality and resistance to diseases and pests, reducing the risk of disease and pest infection during grafting and improving the grafting survival rate.

[0034] In this invention, it is preferable to select branches of moderate thickness from excellent ancient red pine mother trees as scions, generally with a diameter of 0.5-1cm. Branches that are too thick or too thin will have an adverse effect on the grafting effect.

[0035] In this invention, fertilizer A is applied to the scion mother plants 6 months before grafting. Fertilizer A is preferably a mixture of organic fertilizer and superphosphate fertilizer, with a preferred mass ratio of (300-400):(25-35), further preferably (320-380):(28-32), and even more preferably 350:30. The organic fertilizer contains ≥268 million viable bacteria / g and has an organic matter content ≥59%; the superphosphate fertilizer contains ≥12.0% effective P2O5.

[0036] In this invention, the preferred application rate of fertilizer A is 60-80 kg / mu, more preferably 65-75 kg / mu, and even more preferably 70 kg / mu; the preferred number of applications of fertilizer A is 1-2 times, more preferably once.

[0037] In this invention, the scions are pretreated by immersing the lower 3-4 cm portion of the scion in a soaking solution for a preferred soaking time of 15-20 minutes, more preferably 16-19 minutes, and even more preferably 18 minutes. Preferably, 50-80 scions are treated per 1000 mL of soaking solution. The soaking solution comprises glucose, trehalose, propylene glycol, zinc thiazide, indolebutyric acid, vitamin C, and water. The use of propylene glycol forms a protective film to reduce moisture evaporation and enhances the permeability of the pharmaceutical components; vitamin C inhibits the activity of polyphenol oxidase in the scion, preventing xylem browning; zinc thiazide inhibits fungi and bacteria that cause scion rot; and indolebutyric acid promotes cambium cell division and accelerates callus differentiation.

[0038] In this invention, the glucose is preferably 10-15 parts by weight, more preferably 11-14 parts, and even more preferably 12 parts; the trehalose is preferably 8-12 parts by weight, more preferably 9-11 parts, and even more preferably 10 parts; the propylene glycol is preferably 5-8 parts by weight, more preferably 5.5-7 parts, and even more preferably 6 parts; and the thiazolyl zinc is preferably 2-3 parts by weight, more preferably 2.2-2.8 parts. More preferably, the amount is 2.5 parts; the indolebutyric acid is preferably 0.3-0.6 parts by weight, more preferably 0.4-0.55 parts, and even more preferably 0.5 parts; the vitamin C is preferably 0.3-0.5 parts by weight, more preferably 0.35-0.45 parts, and even more preferably 0.4 parts; the water is preferably 900-1100 parts by weight, more preferably 950-1050 parts, and even more preferably 1000 parts.

[0039] In this invention, the rootstock and pretreated scion are grafted using a cleft grafting method, preferably in January or February. The preferred cleft grafting method is as follows: First, the rootstock is cut 10-15cm above the ground, and a 2-3cm deep incision is made vertically downwards from one side of the cut surface; then, the lower end of the scion is shaped into a bevel (2-3cm long) matching the rootstock incision, retaining 1-2 buds at the upper end of the scion; finally, the beveled scion is inserted into the rootstock incision, ensuring that the cambium layers of both are aligned.

[0040] In this invention, a healing-promoting solution is applied to the interface. The healing-promoting solution preferably comprises the following components in parts by weight: 0.8-1.2 parts naphthaleneacetic acid, 0.2-0.4 parts 6-benzylaminopurine, 0.3-0.7 parts brassinolide, 8-12 parts yeast extract, 5-8 parts potassium dihydrogen phosphate, 3-5 parts chitosan, 3-5 parts propylene glycol, and 900-1100 parts water; more preferably, it comprises 0.9-1.1 parts naphthaleneacetic acid and 6-benzylaminopurine... 0.25-0.35 parts, brassinolide 0.4-0.6 parts, yeast extract 9-11 parts, potassium dihydrogen phosphate 5.5-7 parts, chitosan 3.5-4.5 parts, propylene glycol 3.5-4.5 parts, and water 950-1050 parts; more preferably, 1 part naphthaleneacetic acid, 0.3 parts 6-benzylaminopurine, 0.5 parts brassinolide, 10 parts yeast extract, 6 parts potassium dihydrogen phosphate, 4 parts chitosan, 4 parts propylene glycol, and water 1000 parts.

[0041] In this invention, each 1000 mL of the healing-promoting solution is preferably sufficient to cover 60-90 graft interfaces.

[0042] In this invention, after applying the healing-promoting solution, the interface is bound. The binding method involves sequentially wrapping and covering the interface and the surrounding 2-3cm area with a transparent polyethylene film, absorbent cotton soaked in a 450-550 times diluted carbendazim solution, and an elastic plastic bandage. Preferably, a 0.02-0.03mm thick transparent polyethylene film is used as the inner moisturizing film to ensure the interface is in a sealed and moisturizing environment, preventing moisture evaporation. Preferably, a 1-2cm thick absorbent cotton soaked in carbendazim solution is used as the middle antibacterial cotton, which can continuously release antibacterial components and prevent bacterial invasion. The tightness of the elastic plastic bandage should be such that it is "not loose and does not compress the interface."

[0043] In this invention, fertilizer B is applied in the 5th week after grafting. Fertilizer B is preferably a nitrogen-phosphorus-potassium (NPK) compound fertilizer, and the N, P2O5, and K2O mass ratio of the N, P2O5, and K2O in the N, P2O5, and K2O compound fertilizer is preferably (0.8-1.2):1:1, further preferably (0.9-1.1):1:1, and even more preferably 1:1:1.

[0044] In this invention, the preferred application amount of fertilizer B is 80-100g / plant, more preferably 85-95g / plant, and even more preferably 90g / plant; the preferred number of fertilizations is 1-2 times, and more preferably 1 time.

[0045] In this invention, fertilizer C is applied every 15 days from the third month after grafting until the graft is removed from the nursery. Fertilizer C is preferably urea and trace element fertilizer, with the mass ratio of urea to trace element fertilizer preferably being (1-3):(0.5-1), further preferably (1.5-2.8):(0.6-0.9), and even more preferably 2.2:0.8.

[0046] In this invention, the micronutrient fertilizer is preferably zinc fertilizer, boron fertilizer, iron fertilizer or magnesium fertilizer.

[0047] In this invention, the application rate of fertilizer C is preferably 100-200g / plant, more preferably 120-180g / plant, and even more preferably 150g / plant.

[0048] In this invention, during the entire period of cultivating robust seedlings of the grafted Conophytum purpureus, it is preferable to control the soil moisture content at 60%-70% to avoid waterlogging that could lead to root rot.

[0049] The technical solutions provided by the present invention will be described in detail below with reference to the embodiments, but they should not be construed as limiting the scope of protection of the present invention.

[0050] Example 1

[0051] A method for propagating robust seedlings of ancient Conifer spp. through grafting, with the following steps:

[0052] (1) Six months before grafting, apply fertilizer A to the scion mother plants at a rate of 70 kg / mu; fertilizer A is an organic fertilizer and superphosphate fertilizer with a mass ratio of 350:30, wherein the organic fertilizer has an effective viable bacteria count of 270-300 million / g and an organic matter content of 59-62%; and the superphosphate fertilizer has an effective P2O5 content of 12-13%.

[0053] (2) Select healthy, disease-free, and 2-3 year old Conifer seedlings as rootstocks, and select branches with a diameter of 0.8 cm from excellent ancient Conifer mother trees as scions;

[0054] (3) Soak the lower 3cm portion of the scion in the soaking solution for 18 minutes, preferably treating 60 scions per 1000mL of soaking solution; the soaking solution consists of 12 parts glucose, 10 parts trehalose, 6 parts propylene glycol, 2.5 parts zinc thiazolyl, 0.5 parts indolebutyric acid, 0.4 parts vitamin C and 1000 parts water;

[0055] (4) The rootstock and the pretreated scion are grafted by cleft grafting, and a healing-promoting solution is applied to the interface. Then, a 0.02 mm thick transparent polyethylene film, a 1 cm thick cotton wool soaked in 500 times carbendazim solution, and an elastic plastic bandage are used to wrap and cover the interface and the surrounding 2 cm area. The healing-promoting solution has the following components in parts by weight: 1 part naphthaleneacetic acid, 0.3 parts 6-benzylaminopurine, 0.5 parts brassinolide, 10 parts yeast extract, 6 parts potassium dihydrogen phosphate, 4 parts chitosan, 4 parts propylene glycol, and 1000 parts water. Preferably, 1000 mL of the healing-promoting solution can be applied to 80 scion interfaces.

[0056] (5) In the 5th week after grafting, apply a nitrogen-phosphorus-potassium compound fertilizer with a mass ratio of N, P2O5 and K2O of 1:1:1, 90g / plant, once;

[0057] (6) From the third month after grafting until the plant is ready for transplanting, apply fertilizer C every 15 days. The fertilizer C is urea and zinc fertilizer in a mass ratio of 2.2:0.8, 150g / plant.

[0058] (7) During the entire period of cultivating strong seedlings of Conophytum purpureus grafted seedlings, the soil moisture content should be controlled at 60%-65%.

[0059] Example 2

[0060] A method for propagating robust seedlings of ancient Conifer spp. through grafting, with the following steps:

[0061] (1) Six months before grafting, apply fertilizer A to the scion mother plants at a rate of 60 kg / mu; fertilizer A is an organic fertilizer and superphosphate fertilizer with a mass ratio of 300:25, wherein the organic fertilizer has an effective viable bacteria count of 270-300 million / g and an organic matter content of 59-63%; and the superphosphate fertilizer has an effective P2O5 content of 12-13%.

[0062] (2) Select healthy, disease-free, and 2-3 year old Conifer seedlings as rootstocks, and select branches with a diameter of 1 cm from excellent ancient Conifer mother trees as scions;

[0063] (3) Soak the lower 4cm part of the scion in the soaking solution for 15 minutes. Preferably, 80 scions are treated with 1000mL of soaking solution. The soaking solution consists of 10 parts glucose, 12 parts trehalose, 5 parts propylene glycol, 2 parts zinc thiazide, 0.3 parts indolebutyric acid, 0.5 parts vitamin C and 1000 parts water.

[0064] (4) The rootstock and the pretreated scion are grafted by cleft grafting, and a healing-promoting solution is applied to the interface. Then, a 0.02 mm thick transparent polyethylene film, a 1 cm thick cotton wool soaked in 550 times carbendazim solution, and an elastic plastic bandage are used to wrap and cover the interface and the surrounding 2 cm area. The healing-promoting solution has the following components in parts by weight: 0.8 parts naphthaleneacetic acid, 0.4 parts 6-benzylaminopurine, 0.3 parts brassinolide, 12 parts yeast extract, 5 parts potassium dihydrogen phosphate, 3 parts chitosan, 5 parts propylene glycol, and 1000 parts water. Preferably, 1000 mL of the healing-promoting solution can be applied to 90 scion interfaces.

[0065] (5) In the 5th week after grafting, apply a nitrogen, phosphorus and potassium compound fertilizer with a mass ratio of N, P2O5 and K2O of 1.2:1:1, 80g / plant, once;

[0066] (6) From the third month after grafting until the plant is ready for transplanting, apply fertilizer C every 15 days. Fertilizer C is urea and magnesium fertilizer in a mass ratio of 1:0.5, 100 kg / plant.

[0067] (7) During the entire period of cultivating strong seedlings of Conophytum purpureus grafted seedlings, the soil moisture content should be controlled at 60%-65%.

[0068] Example 3

[0069] A method for propagating robust seedlings of ancient Conifer spp. through grafting, with the following steps:

[0070] (1) Six months before grafting, apply fertilizer A to the scion mother plants at a rate of 80 kg / mu; fertilizer A is organic fertilizer and superphosphate fertilizer with a mass ratio of 400:35, wherein the organic fertilizer has an effective live bacteria count of 280-350 million / g and an organic matter content of 59-62%; and the superphosphate fertilizer has an effective P2O5 content of 12-13%.

[0071] (2) Select healthy, disease-free, and 2-3 year old Conifer seedlings as rootstocks, and select branches with a diameter of 0.5 cm from excellent ancient Conifer mother trees as scions;

[0072] (3) Soak the lower 3cm part of the scion in the soaking solution for 20 minutes. Preferably, 50 scions are treated with 1000mL of soaking solution. The soaking solution consists of 15 parts glucose, 8 parts trehalose, 8 parts propylene glycol, 3 parts zinc thiazide, 0.6 parts indolebutyric acid, 0.3 parts vitamin C and 1000 parts water.

[0073] (4) The rootstock and the pretreated scion are grafted by cleft grafting, and a healing-promoting solution is applied to the interface. Then, a 0.02 mm thick transparent polyethylene film, a 1 cm thick cotton wool soaked in 450 times carbendazim solution, and an elastic plastic bandage are used to wrap and cover the interface and the surrounding 2 cm area. The healing-promoting solution has the following components in parts by weight: 1.2 parts naphthaleneacetic acid, 0.2 parts 6-benzylaminopurine, 0.7 parts brassinolide, 8 parts yeast extract, 8 parts potassium dihydrogen phosphate, 5 parts chitosan, 3 parts propylene glycol, and 1000 parts water. Preferably, 1000 mL of the healing-promoting solution can be applied to 70 scion interfaces.

[0074] (5) In the 5th week after grafting, apply a nitrogen, phosphorus and potassium compound fertilizer with a mass ratio of N, P2O5 and K2O of 0.8:1:1, 100g / plant, once;

[0075] (6) From the third month after grafting until the plant is ready for transplanting, apply fertilizer C every 15 days. Fertilizer C is composed of urea and boron fertilizer in a mass ratio of 3:1, 200 kg / plant.

[0076] (7) During the entire period of cultivating strong seedlings of Conophytum purpureus grafted seedlings, the soil moisture content should be controlled at 60%-65%.

[0077] Comparative Example 1

[0078] Similar to Example 1, only the scions were not pretreated with soaking solution.

[0079] Comparative Example 2

[0080] Similar to Example 1, only the interface is not coated with a healing-promoting solution.

[0081] Comparative Example 3

[0082] Similar to Example 1, only elastic plastic straps are used to wrap and cover the interface and the surrounding 2cm area.

[0083] Comparative Example 4

[0084] Similar to Example 1, only the processing in step (1) is discarded.

[0085] Comparative Example 5

[0086] Similar to Example 1, except that “apply NPK compound fertilizer with a mass ratio of N, P2O5 and K2O of 0.8:1:1, 100g / plant, once in the 5th week after grafting” is replaced with “apply NPK compound fertilizer with a mass ratio of N, P2O5 and K2O of 0.2:1:1, 100g / plant, once in the 5th week after grafting”.

[0087] Comparative Example 6

[0088] Similar to Example 1, only step (6) is discarded.

[0089] Experimental Example 1

[0090] The experimental site was located at the Guangdong Academy of Forestry Sciences (23°36′5″N, 113°9′E), in a marine subtropical monsoon climate zone. The average annual temperature was 22.8℃, the average annual rainfall was 2033.5 mm, and the average annual relative humidity was 77%. Carefully selected, robust, and disease-free two-year-old *Castanopsis fargesii* seedlings were randomly chosen as rootstocks, with a height of 30-35 cm and a ground diameter of approximately 1.5-2 cm. Scions were collected from superior ancient *Castanopsis fargesii* trees in the Huaiji Ancient Tree Park. The mother trees were over 130 years old. One-year-old branches from the upper and middle parts of the crown, with robust growth, plump buds, and high lignification, were selected as scions. The branches had a diameter of 0.5-1 cm, and the scions were 10-15 cm long, each with 2-3 plump buds.

[0091] The rootstocks and scions were randomly divided into 10 groups, with 100 rootstocks and 100 scions in each group. These groups included a blank group, Example 1 group, Example 2 group, Example 3 group, Comparative Example 1 group, Comparative Example 2 group, Comparative Example 3 group, Comparative Example 4 group, Comparative Example 5 group, and Comparative Example 6 group. The corresponding groups were grafted and propagated according to the procedures of Examples 1-3 and Comparative Examples 1-6, respectively.

[0092] The blank group was grafted using conventional methods, with no other treatments performed on the rootstock and scion.

[0093] (a) Interface healing status

[0094] Observe the healing of the graft union in each treatment group.

[0095] Table 1. Average healing time of grafted seedlings that survived in different treatment groups.

[0096]

[0097] As shown in Table 1, the grafted seedlings in the embodiment of this invention basically healed at the interface within 13-14 days, and the healed tissue was dense and of normal color. Compared with other groups (except the control group), the grafted seedlings in Comparative Example 1 and Comparative Example 2, which did not use soaking solution or healing-promoting solution, had a longer healing time. Therefore, the propagation method described in this invention can effectively shorten the interface healing time and improve the healing effect.

[0098] (ii) Grafting survival rate

[0099] Survival rate = Number of grafted plants that survive / Total number of grafted plants

[0100] Table 2. Grafting survival rate of grafted seedlings in different treatment groups.

[0101]

[0102] As can be seen from Table 2, the propagation method described in this invention can significantly improve the grafting survival rate, which can reach over 90%.

[0103] (III) Seedling growth indicators

[0104] After one year of cultivation, various indicators of the grafted seedlings in each group were measured, including seedling height and ground diameter.

[0105] Table 3. Seedling height and diameter at ground level of grafted seedlings in different treatment groups.

[0106]

[0107] As shown in Table 3, the seedling height and ground diameter of the grafted seedlings in the Example Group and the Comparative Group were higher than those in the blank group, and the grafted seedlings in the Example Group had the best growth effect.

[0108] (iv) Root system development

[0109] After one year of cultivation, the photosynthetic capacity of the grafted seedlings in each group was measured, and indicators such as net photosynthetic rate and stomatal conductance were recorded.

[0110] Table 4. Measurement of photosynthetic indicators of seedlings in different treatment groups

[0111]

[0112] As can be seen from Table 4, the example group can effectively improve the net photosynthetic rate and transpiration rate of seedlings, which is more conducive to the synthesis and accumulation of nutrients in seedlings, resulting in stronger growth.

[0113] In summary, this invention improves the survival rate and growth quality of grafted seedlings of ancient Chinese red pine trees by optimizing interface processing and fertilization management, thus solving problems such as low survival rate and weak growth in the propagation of grafted seedlings of ancient Chinese red pine trees.

[0114] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A method for propagating robust seedlings of ancient *Castanopsis fargesii* trees through grafting, characterized in that... Includes the following steps: (1) Apply fertilizer A to the mother plant for grafting 6 months before grafting; (2) The rootstock and the pretreated scion are grafted by cleft grafting, and a healing agent is applied to the joint and then bound. (3) Apply fertilizer B in the 5th week after grafting; (4) Apply fertilizer C every 15 days from the third month after grafting until the graft is removed from the nursery. The fertilizer A mentioned in step (1) is an organic fertilizer and superphosphate fertilizer with a mass ratio of (300-400):(25-35); The organic fertilizer contains ≥268 million viable bacteria / g and ≥59% organic matter content; The content of available P2O5 in the superphosphate fertilizer is ≥12.0%; The application rate of fertilizer A in step (1) is 60-80 kg / mu, and the number of fertilizations is 1-2 times; The pretreatment method described in step (2) is as follows: soak the lower 3-4 cm part of the scion in the soaking solution for 15-20 minutes; The soaking solution comprises: 10-15 parts glucose, 8-12 parts trehalose, 5-8 parts propylene glycol, 2-3 parts zinc thiazolyl, 0.3-0.6 parts indolebutyric acid, 0.3-0.5 parts vitamin C, and 900-1100 parts water. The healing-promoting solution is composed of the following components in parts by weight: 0.8-1.2 parts naphthaleneacetic acid, 0.2-0.4 parts 6-benzylaminopurine, 0.3-0.7 parts brassinolide, 8-12 parts yeast extract, 5-8 parts potassium dihydrogen phosphate, 3-5 parts chitosan, 3-5 parts propylene glycol, and 900-1100 parts water; The binding method is as follows: use a transparent polyethylene film, absorbent cotton soaked in 450-550 times carbendazim solution, and elastic plastic straps to wrap and cover the interface and the surrounding 2-3cm area. Fertilizer B mentioned in step (3) is a nitrogen-phosphorus-potassium compound fertilizer; The mass ratio of N, P2O5, and K2O in the nitrogen-phosphorus-potassium compound fertilizer is (0.8-1.2):1:1; The amount of fertilizer B applied in step (3) is 80-100g / plant, and the number of fertilizations is 1-2 times; The fertilizer C mentioned in step (4) is urea and trace element fertilizer in a mass ratio of (1-3):(0.5-1); The micronutrient fertilizer is zinc fertilizer, boron fertilizer, iron fertilizer or magnesium fertilizer; The application rate of fertilizer C is 100-200g / plant.

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