A method for breeding young Wogan orange seedlings

Abstract

The present invention discloses a method for breeding young Wogan citrus seedlings, which relates to the technical field of citrus breeding. The breeding method includes: (1) Cultivation of rootstock seedlings: Soak the rootstock seeds in warm water and a disease-preventing solution and then sow them. Before transplanting the small seedlings, soak the roots in the disease-preventing solution first. The disease-preventing solution contains diethyl aminoethyl hexanoate, plant-derived glycerides, chlorobromoisocyanuric acid, imidacloprid, and beta-cyfluthrin; (2) Cultivation of scion mother trees: In spring, plant the virus-free Wogan scion mother trees and carry out reasonable fertilization, shoot control, and pest and disease control. Cuttings can be taken in the second year after planting; (3) Grafting: Select disease-free, plump, and mature Wogan scions on the scion mother trees and graft them onto the rootstock by single-bud cutting method. Soak the scions in a nutrient solution before grafting. The nutrient solution contains grape seed oil, sodium nitrophenolate, proline, wood vinegar liquid, and sodium alginate. The present invention can improve the survival rate of grafted seedlings, prevent the grafted seedlings from carrying the bacteria of citrus canker, and also prevent the roots of the grafted seedlings from being exposed during planting.

Description

Technical Field

[0001] The present invention relates to the technical field of citrus breeding, and particularly to a method for breeding young Wogan citrus seedlings. Background Art

[0002] Wogan is a late-maturing hybrid citrus variety that has emerged in China in recent years. It has the characteristics of beautiful fruit appearance, excellent quality, late maturity, early fruiting and high yield, long fruit harvesting period, and wide adaptability. In recent years, Guangxi has actively introduced Wogan, and the planting area has expanded rapidly, which has increased the demand for young Wogan citrus seedlings.

[0003] The existing methods for breeding young Wogan citrus seedlings mainly include seedling, layering, cutting, and grafting, among which grafting is the best and most common method. The grafted seedlings of Wogan are composed of scions and rootstock seedlings. At present, there are mainly two ways of grafting and breeding Wogan: container seedlings and field seedlings. Container seedlings are prepared by filling a container with a nutrient soil matrix, transplanting the rootstock seedlings into it and growing them to an appropriate size, and then grafting the scion variety onto the rootstock seedlings to cultivate the seedlings growing in the container. Field seedlings are obtained by grafting the scion variety onto the rootstock seedlings after planting the rootstock seedlings in the seedling bed. In actual production practice, due to the fact that the roots of field seedlings are not with soil during transportation and transplantation, there is a slow seedling stage after direct planting in the field, and the growth rate of the plants is relatively slow. While the roots of container seedlings are with soil, there is no slow seedling stage and the growth is good. Therefore, the state vigorously promotes the application of container seedlings. However, due to the loose matrix of container seedlings, the nutrient soil is prone to water loss and drying during transportation. Coupled with the factors of road vibration and manual handling, the soil in the container is easy to scatter and separate from the roots, which will cause the roots of the grafted seedlings to be exposed, and there will also be a slow seedling stage during planting. At the same time, the survival rate of grafting is also low. In addition, Wogan is prone to infection by citrus canker, and citrus canker has a latent period, so it is necessary to kill it at the source of the grafted seedlings to prevent latent hazards.

[0004] In summary, the purpose of the present invention is to provide a method for breeding young Wogan citrus seedlings to solve the problems of low survival rate of grafting and breeding, latent carrying of citrus canker bacteria by grafted seedlings, and easy loosening and falling of the soil in container seedlings. Summary of the Invention

[0005] In view of the above deficiencies, the present invention provides a method for breeding young Wogan citrus seedlings, which can improve the survival rate of grafted seedlings, prevent grafted seedlings from carrying citrus canker bacteria, and also prevent the roots of grafted container seedlings from being exposed during planting. The specific technical solutions are as follows:

[0006] A method for breeding young Wogan citrus seedlings, comprising the following steps:

[0007] (1) Rootstock seedling cultivation: Select excellent rootstock seeds without diseases and pests. First, soak them in warm water at a constant temperature of 30 - 50 min, then put them into the disease prevention solution and continue to soak for 20 - 30 min, and then dry them. Sow the seeds and carry out seedling emergence management; when the height of the small seedlings is above 20 cm, start transplanting. Before transplanting, soak the roots of the small seedlings in the disease prevention solution for 10 - 20 min, and after soaking, transplant them into containers;

[0008] The disease prevention solution contains 1 - 5 g of DA-6, 10 - 20 g of plant-derived glycerides, 3 - 10 g of chlorobromoisocyanuric acid, 6 - 15 mL of imidacloprid, and 10 - 14 mL of beta-cyfluthrin per 1 kg, and the rest is water;

[0009] (2) Cultivation of scion mother trees: In spring, plant the virus-free Wogan scion mother trees, and carry out reasonable fertilization, shoot control, and pest and disease control. All fruits on the trees need to be removed during the cultivation period. Cuttings can be taken in the second year after planting;

[0010] The fertilization is as follows: In spring, apply fertilizers with a nitrogen-phosphorus-potassium ratio of 4:1:2, and the fertilizer application rate is 30 - 50 g / plant, applied 2 - 3 times per month; in summer, apply fertilizers with a nitrogen-phosphorus-potassium ratio of 2:1:3, and the fertilizer application rate is 100 - 200 g / plant, applied 1 - 2 times per month; in autumn and winter, mainly apply organic fertilizers, and the fertilizer application rate is 5 - 10 kg / plant, applied 1 - 2 times per month;

[0011] The shoot control is as follows: After the summer shoots emerge, remove the strong shoots and leave the weak shoots; after the autumn shoots emerge, thin out the shoots, and leave 40 - 50% of the autumn shoots per plant;

[0012] The pest and disease control is as follows: Spray pesticides during the high-incidence period of citrus canker, once every 15 - 20 days; the pesticides are 1500 - 2000 times the aqueous solution of 46.1% copper hydroxide wettable powder or 1000 - 1500 times the aqueous solution of 31.5% quinoline copper suspension;

[0013] (3) Grafting: In September - October, select disease-free, plump, and mature Wogan scions on the scion mother trees, and graft them onto the rootstocks by single-bud cut grafting method. Before grafting, soak the scions in the nutrient solution. The nutrient solution contains 10 - 20 g of grape seed oil, 0.5 - 1 g of sodium nitrophenolate, 0.1 - 0.5 g of proline, 6 - 15 g of wood vinegar liquid, 1 - 6 g of sodium alginate per 500 mL, and the balance is water.

[0014] Preferably, the warm water is at 40 - 50 °C.

[0015] Preferably, the sowing time of the rootstock is from November to December.

[0016] Preferably, the sowing is as follows: Evenly spread the treated rootstock seeds on the seedbed, and the sowing density is 400 - 500 seeds / m3 , then cover the seeds with humus soil. The thickness of the covering soil is 2 - 3 times the diameter of the seeds. After covering the soil, water thoroughly and cover with a plastic film.

[0017] Preferably, for the seedling emergence management, after sowing, keep the soil temperature in the seedbed at 25 - 30 °C and the relative humidity at 85% - 90%. Spray a fungicide once every 10 - 20 days after emergence. When the seedling height is above 5 cm, top-dress with a 0.2% - 0.4% compound fertilizer solution.

[0018] Preferably, the rootstock is trifoliate orange or sour orange.

[0019] Preferably, the container is a nutrient bag or a plastic pot made of plastic, and only one small seedling can be transplanted into each container.

[0020] Preferably, for the transplantation, it also includes mixing a curing agent and a transplanting substrate evenly at a weight ratio of 1:100 - 200, filling the mixed substrate into the container, and then carrying out the transplantation. After transplantation, water thoroughly; the curing agent includes the following raw materials in parts by weight: 1 - 2 parts of polyacrylamide and 3 - 6 parts of carboxymethyl cellulose.

[0021] Preferably, during grafting, the nutrient solution should also be applied to the grafting interface of the rootstock.

[0022] Preferably, the steps also include the management of grafted seedlings, and the management is as follows: timely remove the tender buds germinated on the main trunk of the rootstock. When the height of the grafted seedling reaches 30 - 40 cm, select 3 - 5 thick and strong lateral branches with appropriate directions and angles as the first-level lateral branches. When the second shoot germinated from the scion matures and ages, it can be taken out of the nursery.

[0023] Compared with the prior art, the beneficial effects of the present invention are:

[0024] 1. In the stage of cultivating rootstock seedlings, the present invention uses a disease-preventing liquid to treat the seeds and rootstock seedlings. The disease-preventing liquid can effectively prevent the bacteria of citrus canker from invading the rootstock seeds and plants for latency, and further prevent the occurrence of citrus canker disease in grafted seedlings. Among them, diethyl aminoethyl hexanoate can increase the plant body rate, enhance the accumulation of nutrients in the plant body, and improve the disease resistance of plants; plant-derived glycerides have ductility and permeability, and can enhance the efficacy of chlorobromoisocyanuric acid, imidacloprid and beta-cyfluthrin; chlorobromoisocyanuric acid can kill various fungi and bacteria, including the bacteria of citrus canker; imidacloprid and beta-cyfluthrin can kill pests such as leafminers, citrus leaf beetles and papilio xuthus, prevent pests from causing wounds on the rootstock, and further prevent the bacteria of citrus canker from invading the wounds for latency.

[0025] 2. When cultivating the ear - taking mother tree of the present invention, reasonable fertilization, shoot control, and pest and disease control are carried out on the mother tree, which can effectively prevent the invasion of the canker disease bacteria into the scion for latency. Among them, fertilization is carried out by increasing the amount of nitrogen fertilizer in spring and decreasing the amount of nitrogen fertilizer in summer, which can ensure the healthy growth of the mother tree while reducing the occurrence of canker disease; shoot control is carried out by removing strong summer shoots and thinning autumn shoots, which can reduce the occurrence of canker disease.

[0026] 3. The present invention uses a curing agent to treat the rootstock transplanting substrate. Polyacrylamide in the curing agent is a water - soluble linear polymer with good flocculability, which can stabilize the substrate soil. Carboxymethyl cellulose not only has an adhesive effect but also can retain moisture. The synergistic effect of the two can make the rootstock transplanting substrate form a stable structure, not easy to dehydrate and dry, and not easy to scatter and separate from the roots. When the grafted seedling is planted without the container, its roots still have a complete and moist soil ball, so the planting is fast and there is no slow - seedling period.

[0027] 4. When grafting in the present invention, treating the scion with a nutrient solution can keep the wound surface moist, accelerate the repair of the wound surface, speed up the combination of the scion and the rootstock, and improve the grafting survival rate. Grape seed oil in the nutrient solution is rich in linoleic acid, procyanidins, vitamin E, amino acids, and mineral elements, which can provide nutrition, moisturize, and also have antioxidant and antibacterial properties, and can be quickly absorbed by the plant wound surface; compound sodium nitrophenolate and proline can improve stress resistance and accelerate wound healing; wood vinegar can stimulate the plant to repair the wound; sodium alginate has viscosity and can promote the adsorption of the above - mentioned drugs on the wound surface. Detailed implementation manners

[0028] The following will describe the detailed implementation manners of the present invention in detail, but it should be understood that the protection scope of the present invention is not limited by the detailed implementation manners.

[0029] Example 1

[0030] A method for breeding young Wogan seedlings in this example includes the following steps:

[0031] (1) Cultivation of rootstock seedlings:

[0032] Sowing: In November 2021, select excellent rootstock seeds without pests and diseases. First, soak them in warm water at 40 °C for 30 minutes, then put them into the disease - prevention solution and continue to soak for 20 minutes, and then dry them. Evenly spread the dried rootstock seeds on the seedbed, with a sowing density of 400 seeds / m 3 , then cover the seeds with humus soil, and the thickness of the covering soil is 2 times the diameter of the seeds. After watering thoroughly, cover with a plastic film. After sowing, keep the ground temperature of the seedbed at 25 °C and the relative humidity at 85%. Spray a fungicide once every 10 days after emergence. When the seedling height is above 5 cm, top - dress with a 0.2% compound fertilizer solution.

[0033] Transplanting: Transplanting starts when the height of the young seedlings is above 20 cm. Before transplanting, first treat the substrate with a curing agent, that is, mix the curing agent and the substrate evenly at a weight ratio of 1:100 and put them into a plastic nutrient bag. Then soak the roots of the young seedlings in the disease-preventing liquid for 10 minutes. After soaking, start transplanting. Only one young seedling can be transplanted into each nutrient bag. After transplanting, water thoroughly.

[0034] Among them, each 1 kg of the above-mentioned disease-preventing liquid contains 1 g of amine fresh ester, 10 g of plant-derived glyceride, 3 g of chlorobromoisocyanuric acid, 6 mL of imidacloprid, and 10 mL of beta-cyfluthrin, and the rest is water.

[0035] The above-mentioned curing agent includes the following raw materials in parts by weight: 1 part of polyacrylamide and 3 parts of carboxymethyl cellulose.

[0036] (2) Cultivation of scion mother trees: In the spring of 2021, plant the virus-free Wogan scion mother trees, and carry out reasonable fertilization, shoot control, and pest and disease control. All fruits on the trees need to be removed during the cultivation period. Cuttings can be taken in the second year after planting; the specific fertilization method is as follows: In spring, apply fertilizers with a nitrogen, phosphorus, and potassium ratio of 4:1:2, and the fertilizer application rate is 30 g / plant, applied 2 times a month; in summer, apply fertilizers with a nitrogen, phosphorus, and potassium ratio of 2:1:3, and the fertilizer application rate is 100 g / plant, applied 1 time a month; in autumn and winter, mainly apply organic fertilizers, and the fertilizer application rate is 5 kg / plant, applied 1 time a month; the specific shoot control method is as follows: After the summer shoots emerge, wipe out the strong shoots and leave the weak shoots; after the autumn shoots emerge, thin out the shoots, and only leave 40% of the autumn shoots per plant; the specific pest and disease control is as follows: Spray the medicine during the high-incidence period of citrus canker, once every 15 days; the medicine is a 1500-fold solution of 46.1% copper hydroxide wettable powder aqueous solution.

[0037] (3) Grafting: In September 2022, select disease-free, plump, and mature Wogan scions on the above-mentioned scion mother trees, and use the single-bud cutting method to graft them onto the rootstock. Before grafting, soak the scions in the nutrient solution, and also apply the nutrient solution to the grafting interface of the rootstock during grafting. Each 500 mL of the nutrient solution contains 10 g of grape seed oil, 0.5 g of sodium nitrophenolate, 0.1 g of proline, 6 g of wood vinegar liquid, 1 g of sodium alginate, and the balance is water.

[0038] (4) Management of grafted seedlings: Timely wipe out the tender buds germinated on the main trunk of the rootstock. When the height of the grafted seedlings reaches 30 cm, select 3 thick and strong lateral branches with appropriate directions and angles as the first-level lateral branches. When the second shoot germinated from the scion matures and ages, it can be taken out of the nursery.

[0039] The rootstock used in this example is trifoliate orange.

[0040] Example 2

[0041] A method for breeding Wogan seedlings in this example includes the following steps:

[0042] (1) Cultivation of rootstock seedlings:

[0043] Sowing: In December 2021, select excellent rootstock seeds without diseases and pests. First, soak them in warm water at 50 °C for 50 min, then put them into the disease-preventing liquid and continue to soak for 30 min, and then dry them. Evenly spread the dried rootstock seeds on the seedbed, and the sowing density is 500 seeds / m 3 , then cover the seeds with humus soil, and the thickness of the covering soil is 3 times the diameter of the seeds. After covering the soil, pour enough water and cover with a plastic film. After sowing, keep the ground temperature of the seedbed at 30 °C and the relative humidity at 90%. Spray a fungicide once every 20 days after emergence. When the seedling height is above 5 cm, top-dress with a 0.4% compound fertilizer solution.

[0044] Transplanting: Start transplanting when the height of the small seedlings is above 20 cm. Before transplanting, first treat the substrate with a curing agent, that is, mix the curing agent and the substrate evenly at a weight ratio of 1:200 and put them into a plastic pot. Then soak the roots of the small seedlings in the disease-preventing liquid for 20 min. After soaking, start transplanting. Only one small seedling can be transplanted into each plastic pot. After transplanting, pour enough water.

[0045] Among them, each 1 kg of the above-mentioned disease-preventing liquid contains 5 g of diethyl aminoethyl hexanoate, 20 g of plant-derived glycerides, 10 g of chlorobromoisocyanuric acid, 15 mL of imidacloprid, and 14 mL of beta-cyfluthrin, and the rest is water.

[0046] The above-mentioned curing agent includes the following raw materials in parts by weight: 2 parts of polyacrylamide and 6 parts of carboxymethyl cellulose.

[0047] (2) Cultivation of scion mother trees: In the spring of 2021, plant the virus-free Wogan scion mother trees, and carry out reasonable fertilization, shoot control, and pest and disease control. All fruits on the trees need to be removed during the cultivation period. Cuttings can be taken in the second year after planting; the specific fertilization method is: in spring, apply fertilizers with a nitrogen, phosphorus, and potassium ratio of 4:1:2, and the fertilizer application rate is 50 g / plant, applied 3 times a month; in summer, apply fertilizers with a nitrogen, phosphorus, and potassium ratio of 2:1:3, and the fertilizer application rate is 200 g / plant, applied 2 times a month; in autumn and winter, mainly apply organic fertilizers, and the fertilizer application rate is 10 kg / plant, applied 2 times a month; the specific shoot control method is: remove strong shoots after the summer shoots emerge, and leave weak shoots; after the autumn shoots emerge, thin the shoots, and only leave 50% of the autumn shoots per plant; the specific pest and disease control is: spray the medicine during the high-incidence period of citrus canker, once every 20 days; the medicine is a 1500-fold solution of 31.5% copper quinolate suspension.

[0048] (3) Grafting: In October 2022, select disease-free, plump, and mature Wogan scions from the above-mentioned scion mother trees, and graft them onto the rootstock by the single-bud cutting method. Before grafting, the scions are first soaked in the nutrient solution, and the nutrient solution is also applied to the grafting interface of the rootstock during grafting. Each 500 mL of the nutrient solution contains 20 g of grape seed oil, 1 g of sodium nitrophenolate, 0.5 g of proline, 15 g of wood vinegar, 6 g of sodium alginate, and the balance is water.

[0049] (4) Management of grafted seedlings: Timely remove the tender buds germinated on the main trunk of the rootstock. When the height of the grafted seedlings reaches 40 cm, select 5 thick and strong lateral branches with appropriate directions and angles as the first-level lateral branches. When the second shoot sprouted from the scion matures and ages, the seedlings can be outplanted.

[0050] The rootstock used in this example is sour orange.

[0051] Example 3

[0052] A method for breeding Wogan seedlings in this example includes the following steps:

[0053] (1) Cultivation of rootstock seedlings:

[0054] Sowing: In November 2021, select excellent rootstock seeds without diseases and pests. First, soak them in warm water at 45 °C for 40 min, then put them into the disease-preventing solution and continue to soak for 25 min, and then dry them. Evenly scatter the dried rootstock seeds on the seedbed, and the sowing density is 450 seeds / m 3 , then cover the seeds with humus soil, and the thickness of the covering soil is 3 times the diameter of the seeds. After covering the soil, water thoroughly and cover with a plastic film. After sowing, keep the ground temperature of the seedbed at 28 °C and the relative humidity at 88%. Spray a fungicide once every 15 days after emergence. When the seedling height is above 5 cm, topdress with a 0.3% compound fertilizer solution.

[0055] Transplanting: Start transplanting when the height of the small seedlings is above 20 cm. Before transplanting, first treat the substrate with a curing agent, that is, mix the curing agent and the substrate evenly at a weight ratio of 1:150 and put them into the nutrient bags, then soak the roots of the small seedlings in the disease-preventing solution for 15 min. After soaking, start transplanting. Only one small seedling can be transplanted into each nutrient bag, and water thoroughly after transplanting.

[0056] Among them, each 1 kg of the above-mentioned disease-preventing solution contains 3 g of DA-6, 15 g of plant-derived glyceride, 9 g of chlorobromoisocyanuric acid, 10 mL of imidacloprid, and 12 mL of beta-cyfluthrin, and the rest is water.

[0057] The above-mentioned curing agent includes the following raw materials in parts by weight: 1.5 parts of polyacrylamide and 5 parts of carboxymethyl cellulose.

[0058] (2) Cultivation of mother trees for collecting buds: In the spring of 2021, the detoxified mother trees for collecting buds of Wogan will be planted, and reasonable fertilization, shoot control and pest and disease control will be carried out. During the cultivation period, all fruits on the trees need to be removed, and the scions can be cut in the second year of planting; the specific fertilization method is: in spring, the nitrogen, phosphorus and potassium ratio is 4:1:2, the fertilizer amount is 40g / plant, and it is applied 3 times a month; in summer, the nitrogen, phosphorus and potassium ratio is 2:1:3, the fertilizer amount is 150g / plant, and it is applied once a month; in autumn and winter, organic fertilizer is mainly applied, the fertilizer amount is 6kg / plant, and it is applied once a month; the specific shoot control method is: after the summer shoots are extracted, the strong shoots are wiped off and the weak shoots are left; after the autumn shoots are extracted, the shoots are thinned out, and 45% of the autumn shoots are left on each plant; the specific pest and disease control is: spray the agent during the high incidence period of ulcer disease, and spray once every 16 days; the agent is a 2000 times solution of 46.1% copper hydroxide wettable powder aqueous solution.

[0059] (3) Grafting: In September 2022, disease-free, plump, and mature mandarin orange scions are selected from the above-mentioned scion-collecting mother tree, and the scions are grafted onto the rootstock by single bud grafting. The scions are soaked in nutrient solution before grafting, and the nutrient solution is applied to the grafting port of the rootstock during grafting. Each 500 mL of the nutrient solution contains 15 g of grape seed oil, 0.7 g of sodium nitrophenolate, 0.2 g of proline, 10 g of wood vinegar, 4 g of sodium alginate, and the balance is water.

[0060] (4) Management of grafted seedlings: promptly remove the young buds sprouting from the main trunk of the rootstock. When the height of the grafted seedlings reaches 35 cm, select three strong side branches with suitable directions and angles as the first-level side branches. When the second shoots sprouted from the scion mature and age, they can be transplanted.

[0061] The rootstock used in this embodiment is Fructus Aurantii Immaturus.

[0062] Comparative Example 1

[0063] No disease-proof liquid was used to treat seeds and seedlings during the stock cultivation stage, and other steps were the same as in Example 1.

[0064] Comparative Example 2

[0065] During the stock cultivation stage, conventional canker disease control agent (1500 times solution of 46.1% copper hydroxide wettable powder aqueous solution) was used instead of the disease control solution of the present invention to treat seeds and seedlings, and the other steps were the same as those in Example 1.

[0066] Comparative Example 3

[0067] The fertilization method during the cultivation stage of the bud-collecting mother tree is carried out according to the conventional method, that is, nitrogen fertilizer is applied in the summer, and the other steps are the same as those in Example 1.

[0068] Comparative Example 4

[0069] In the method for controlling shoots during the cultivation stage of the scion mother tree, leave more autumn shoots, that is, thin the shoots after the autumn shoots emerge, leaving 60% of the autumn shoots per plant, and the other steps are the same as those in Example 1.

[0070] The above-mentioned examples and comparative examples were carried out in the Wogan demonstration area of Butang Village, Litang Town, Binyang County. After half a year of planting 50 surviving grafted seedlings in the field for each of the examples and comparative examples 1 to 4, the incidence of citrus canker in each group was counted, and the incidence rate (the percentage of diseased plants in the total number) was counted. The appearance of disease spots on the leaves was considered as disease occurrence, and the field management of each group was the same. The results are shown in Table 1:

[0071] Table 1 Incidence of citrus canker in each group

[0072] Incidence / group Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Incidence rate (%) 12 18 14 36 32 26 24

[0073] The above table shows that in the present invention, the seeds and rootstock seedlings are treated with a disease-preventing solution during the cultivation stage of the rootstock seedlings, and reasonable fertilization, shoot control and pest and disease control are carried out on the mother tree during the cultivation of the scion mother tree, which can effectively prevent the invasion of citrus canker bacteria into the rootstock and scion for latency, and the incidence of citrus canker is reduced after the grafted seedlings are planted in the field.

[0074] Comparative Example 5

[0075] In the grafting step, the scion was not treated with the nutrient solution, and the other steps were the same as those in Example 1.

[0076] Comparative Example 6

[0077] In the grafting step, the scion was treated with a commercially available plant wound healer instead of the nutrient solution of the present invention, and the other steps were the same as those in Example 1.

[0078] The above-mentioned examples and comparative examples were carried out in the Wogan demonstration area of Butang Village, Litang Town, Binyang County. 100 plants were grafted for each of the examples and comparative examples 5 and 6. The survival rate of the grafted seedlings was counted 30 days after grafting. If tender buds appeared on the scion or even if there were no tender buds but it did not wither, the moisture was sufficient, and the grafting wound had healed, it was considered as survival. If the scion withered or mildewed, it was considered as non-survival. The field management of each group was the same. The results are shown in Table 2:

[0079] Table 2 Grafting survival rate of each group

[0080] Incidence / group Example 1 Example 2 Example 3 Comparative Example 5 Comparative Example 6 Survival rate (%) 96 98 95 52 89

[0081] The above table shows that when the scion is treated with the nutrient solution during grafting in the present invention, it can keep the wound surface moist, accelerate the repair of the wound surface, speed up the combination of the scion and the rootstock, and improve the grafting survival rate.

[0082] Comparative Example 7: The substrate was not treated with a curing agent during the rootstock cultivation stage, and the other steps were the same as those in Example 1.

[0083] The above-mentioned examples and comparative examples were carried out in the Wogan demonstration area of Butang Village, Litang Town, Binyang County. For each of the examples and comparative examples, 50 surviving grafted seedlings were selected and planted in the field. When the grafted seedlings were planted in the field, it was observed whether the roots of the grafted seedlings had soil balls after removing the containers. The results are shown in Table 3:

[0084] Table 3 Soil ball conditions of the roots of grafted seedlings in each example and comparative example

[0085] Incidence / group Example 1 Example 2 Example 3 Comparative Example 7 Whether with soil ball Yes Yes Yes No, root soil scattered

[0086] The above table shows that in the present invention, a curing agent is used to treat the substrate for rootstock transplantation. The curing agent can stabilize the substrate soil, maintain the moisture of the substrate soil, make the substrate for rootstock transplantation form a stable structure, is not easy to dehydrate and dry, and is not easy to scatter and separate from the roots. When the grafted seedlings are planted after removing the containers, their roots still have complete and moist soil balls. Therefore, the planting is fast and there is no seedling slowdown period.

[0087] In summary, a method for breeding Wogan seedlings of the present invention can improve the survival rate of grafted seedlings, prevent grafted seedlings from carrying citrus canker bacteria, and can also prevent the roots from being exposed when grafted container seedlings are planted, which is suitable for popularization.

[0088] The foregoing description of specific exemplary embodiments of the invention has been presented for purposes of illustration and example. These descriptions are not intended to limit the invention to the precise forms disclosed, and it is apparent that, according to the above teachings, many modifications and variations are possible. The purpose of selecting and describing the exemplary embodiments is to explain the specific principles of the invention and its practical applications, so that those skilled in the art can implement and utilize various different exemplary embodiments of the invention, as well as various different selections and modifications. The scope of the invention is intended to be defined by the claims and their equivalents.

Claims

1. A method for breeding young Wogan citrus seedlings, characterized in that the following Steps: (1) Rootstock seedling cultivation: Select excellent rootstock seeds without diseases and pests. First, soak them in warm water at 40 - 50°C for heat preservation for 30 - 50 min, then put them into the disease prevention solution and continue to soak for 20 - 30 min, and then dry them. Sow the seeds and conduct seedling emergence management; when the height of the small seedlings is above 20 cm, start transplanting. Before transplanting, soak the roots of the small seedlings in the disease prevention solution for 10 - 20 min, and after soaking, transplant them into containers; The disease prevention solution contains 1 - 5 g of DA - 6 per 1 kg, 10 - 20 g of plant - derived glycerides, 3 - 10 g of chlorobromoisocyanuric acid, 6 - 15 mL of imidacloprid, and 10 - 14 mL of beta - cyfluthrin, and the rest is water; (2) Cultivation of scion mother trees: In spring, plant the virus - free Wogan scion mother trees, and conduct reasonable fertilization, shoot control, and pest and disease control. All fruits on the trees need to be removed during the cultivation period. Cuttings can be taken in the second year after planting; The fertilization is as follows: In spring, apply fertilizers with a nitrogen - phosphorus - potassium ratio of 4:1:2, and the fertilizer application rate is 30 - 50 g per plant, applied 2 - 3 times per month; in summer, apply fertilizers with a nitrogen - phosphorus - potassium ratio of 2:1:3, and the fertilizer application rate is 100 - 200 g per plant, applied 1 - 2 times per month; in autumn and winter, mainly apply organic fertilizers, and the fertilizer application rate is 5 - 10 kg per plant, applied 1 - 2 times per month; The shoot control is as follows: After the summer shoots emerge, wipe out the strong shoots and leave the weak shoots; after the autumn shoots emerge, thin out the shoots, and leave 40 - 50% of the autumn shoots per plant; The pest and disease control is as follows: Spray pesticides during the high - incidence period of citrus canker, spraying once every 15 - 20 days; the pesticides are 1500 - 2000 - fold aqueous solution of 46.1% copper hydroxide wettable powder or 1000 - 1500 - fold aqueous solution of 31.5% quinoline copper suspension; (3) Grafting: In September - October, select disease - free, plump, and mature Wogan scions on the scion mother trees, and graft them onto the rootstock seedlings by single - bud cut - grafting method. Before grafting, soak the scions in the nutrient solution. The nutrient solution contains 10 - 20 g of grape seed oil, 0.5 - 1 g of sodium nitrophenolate, 0.1 - 0.5 g of proline, 6 - 15 g of wood vinegar liquid, 1 - 6 g of sodium alginate per 500 mL, and the balance is water.

2. The method for breeding young Wogan citrus seedlings according to claim 1, characterized in that The warm water is at 40 - 50°C.

3. The method for breeding young Wogan citrus seedlings according to claim 1, characterized in that The sowing time of the rootstock seedlings is from November to December.

4. The method for breeding young Wogan citrus seedlings according to claim 1, characterized in that The sowing is as follows: evenly scatter the processed rootstock seeds on the seedbed, and the sowing density is 400 - 500 seeds / m 2 , then cover the seeds with humus soil, and the thickness of the covering soil is 2 - 3 times the diameter of the seeds. After covering the soil, water thoroughly and cover with a plastic film.

5. The method for breeding young Wogan citrus seedlings according to claim 1, characterized in that The seedling emergence management is to keep the ground temperature of the seedbed at 25 - 30°C and the relative humidity at 85% - 90% after sowing. Spray a fungicide once every 10 - 20 days after seedling emergence, and top - dress with 0.2% - 0.4% compound fertilizer solution when the seedling height is above 5 cm.

6. The method for breeding young Wogan citrus seedlings according to claim 1, characterized in that The rootstock seedlings are trifoliate orange or sour orange.

7. The method for breeding young Wogan citrus seedlings according to claim 1, characterized in that The containers are plastic nutrient bags or plastic pots, and only one small seedling can be transplanted into each container.

8. The method for breeding young Wogan citrus seedlings according to claim 1, characterized in that The transplanting also includes mixing the curing agent and the transplanting substrate evenly at a weight ratio of 1:100 - 200, filling the mixed substrate into the containers, and then transplanting. After transplanting, water thoroughly; the curing agent includes the following raw materials in parts by weight: 1 - 2 parts of polyacrylamide and 3 - 6 parts of carboxymethyl cellulose.

9. The method for breeding young Wogan citrus seedlings according to claim 1, characterized in that During grafting, the nutrient solution should also be applied to the grafting interface of the rootstock seedlings.

10. The method for breeding young Wogan citrus seedlings according to claim 1, characterized in that The above steps further include the management of grafted seedlings, and the management is as follows: timely remove the tender buds germinated on the main trunk of the rootstock; when the height of the grafted seedling reaches 30-40 cm, select 3-5 thick and strong lateral branches with appropriate directions and angles as the first-level lateral branches; when the second shoot germinated from the scion becomes mature and aged, it can be taken out of the nursery.