Cultivation method of double-root-system kiwi fruit grafted seedlings

Abstract

The invention provides a double-root-system kiwi fruit grafted seedling cultivation method which comprises the following steps: S1, stock acquisition: respectively selecting one annual actinidia chinensis seedling and one delicious kiwi fruit seedling as stocks, pruning main roots of the two stocks to be 10-15cm in length, and reserving 4-5cm stems; a branch of a delicious kiwi fruit variety is selected as a scion, the length of the scion is 8-12 cm, the upper end of the scion is sealed with wax or a wound healing agent, and a notch in the lower end of the scion is cut into a smooth plane; s3, grafting: reversely grafting the two stocks at the lower end of the same scion by adopting a bark grafting or cleft grafting mode, and winding and wrapping a grafting part by using a grafting film to form a kiwi fruit seedling grafting body. Grafted seedlings cultivated by the method have two sets of root systems of actinidia valvata and actinidia deliciosa, so that the actinidia valvata and actinidia deliciosa grafted seedlings are high in waterlogging resistance, drought resistance and disease and pest resistance and can absorb comprehensive nutrients, and produced fruits are good in quality and high in yield and have high economic benefits.

Description

Technical Field

[0001] The invention belongs to the technical field of kiwifruit planting, and particularly relates to a method for cultivating double-root kiwifruit grafted seedlings. Background Art

[0002] Kiwifruit is one of the most difficult tree species to cultivate among fruit trees. The main reason is that the traditional kiwifruit rootstock is Actinidia chinensis, which has a low degree of root lignification and poor rooting ability. It has serious defects such as intolerant to waterlogging, drought, barrenness, and susceptibility to ulcers. The root system of Actinidia chinensis has a high degree of root lignification, a dense structure, and a strong rooting ability. It is particularly resistant to water immersion and drought, and has strong resistance to diseases and insects. It is an ideal rootstock. Using the advantages of the root system of Actinidia chinensis to cultivate resistant seedlings is important for solving the problems of drought, waterlogging, disease, and insect damage in kiwifruit cultivation and improving the adaptability of kiwifruit. However, due to the huge difference in the thickening speed of the stems of Actinidia chinensis, Actinidia chinensis, it is easy to have the problem of large and small feet, which affects the survival rate of grafted seedlings and thus reduces the neatness and yield of the orchard.

[0003] At present, there are many technologies related to double-root grafting, but most of them use the high tolerance of different double rootstocks to cultivate seedlings with strong drought resistance, waterlogging resistance, and disease and insect resistance. However, in addition to solving the resistance and survival problems of grafted seedlings, more attention should be paid to the quality and yield of grafted seedlings. After all, high-quality and high-yield agricultural products are what people pursue. Although the existing double-root kiwifruit grafting technology solves the problem of poor affinity of the grafting site of the scion and the death of the trunk caused by serious uneven feet of the grafted seedlings, it does not pay substantial attention to the quality of the fruit and its yield. Summary of the invention

[0004] In view of this, the present invention provides a cultivation method for grafting double rootstocks of Actinidia chinensis and Actinidia dasyphylla with Actinidia dasyphylla scion, so that the survival rate of grafted seedlings is better, the plants grow faster and stronger, and the germination rate, branching rate and fruit setting rate are significantly improved.

[0005] In order to achieve the above object, the present invention adopts the following technical solutions: A method for cultivating double-root kiwifruit grafted seedlings comprises the following steps: S1. Rootstock acquisition: one annual Actinidia kiwifruit and one Actinidia deliciosa seedling were selected as rootstocks, and the taproots of the two rootstocks were trimmed to a length of 10-15 cm, leaving 4-5 cm of stems; S2. Scion acquisition: Select branches of Actinidia selegans as scions. The scions are 8 to 12 cm long, the upper end is sealed with wax or wound healing agent, and the lower end is cut into a smooth surface. S3. Grafting: using the method of bark grafting or cleft grafting, two rootstocks are reversely grafted onto the lower end of the same scion, and the grafted part is wrapped with a grafting film to form a kiwi seedling grafted body; S4. Cultivating grafted seedlings: Cultivate the grafted grafts in a nursery, and transplant them into the field for planting after the grafting sites have healed.

[0006] Furthermore, the rootstock has a stem thickness of 0.4-0.6 cm and has 2-3 main roots; the scion has a stem thickness of more than 1 cm and has more than one full and complete bud.

[0007] In some specific embodiments, preferably, when the grafting is performed by bark grafting, the specific steps are as follows: First, cut the upper end of the stock stem into a 2-3 cm bevel surface, with the top sharpened and the surface made thin; then cut a small bevel with a width of 0.2 cm and a length of 1.5-2 cm on both sides of the incision, and cut a small bevel with a width of 0.2 cm on the upper end of the back; then cut a vertical cut in the cortex from both sides of the lower end of the scion, 2-3 cm long and deep into the xylem; finally, put the cut surfaces of the two stockpiles facing the xylem of the scion, and insert them downward close to the xylem, so that the stock is between the xylem and cortex of the scion, and the inner sides of the bark on both sides cover the two wounds of the stock, and the upper end of the stock is slightly exposed to white to facilitate healing. After inserting the stock, it can be tightly tied with grafting film immediately.

[0008] In some specific embodiments, preferably, when the grafting is performed by cleft grafting, the specific steps are as follows: First, cut both sides of the upper end of the rootstock stem into a 2-3 cm long wedge-shaped slope; then use a cleaving knife to vertically split a 2.5-3.5 cm long cleft from the center of the lower end of the scion; finally, quickly insert the two cut rootstocks, leaving 0.1-0.2 cm of the cut surface of the rootstock outside to facilitate healing. Place the two rootstocks close to both sides of the scion, align the cambium of the scion and the rootstock, and wrap the grafting site with a grafting film.

[0009] Furthermore, indoor false healing is carried out before entering the nursery for cultivation, as follows: the scion is placed downward and the root system is upward, and arranged neatly on the seedbed; then covered with 2 cm thick fine sand, sprayed with water at appropriate times to keep the sand layer moist, and allowed to heal for 15 to 20 days.

[0010] Furthermore, during the cultivation process, after germination, the buds sprouted by the rootstock are promptly thinned out to ensure the healthy growth of the scion buds; after the grafting site is healed, the grafting film is promptly removed.

[0011] Compared with the prior art, the present invention has the following beneficial effects: The kiwifruit seedlings cultivated by the present invention have two sets of root systems of the calyx kiwifruit and the delicious kiwifruit, so they not only have strong waterlogging resistance, drought resistance and disease and insect resistance, but also have excellent growth of grafted seedlings (survival rate 93.3-93.7%, germination rate 71.6-72.2%, branching rate 78.2-78.6%, fruit setting rate 87.1-88.6%); moreover, the nutrients absorbed are very comprehensive, the fruits produced are of good quality and high yield (single fruit weight reaches 90.7-91.6g, per mu yield is 2461-2508kg, and various nutrients are rich in content), and have high economic benefits. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 The flowchart of the double-root kiwifruit grafted seedlings provided in Example 1 of the present invention; wherein a and e are rootstocks, b, c, d are scions, f, g, h are grafted seedlings, and i is a grafted seedling planted in a nursery.

[0013] Figure 2 The flowchart of the double-root kiwifruit grafted seedlings provided in Example 2 of the present invention; wherein a, e, f, g are rootstocks, b, c, d are scions, h, i, j are grafted seedlings, and k is a grafted seedling planted in a nursery. DETAILED DESCRIPTION

[0014] The present invention is further described in detail below in conjunction with specific embodiments so that those skilled in the art can understand the present invention more clearly.

[0015] Example 1 This embodiment provides a method for cultivating double-root kiwifruit grafted seedlings, which is as follows: S1. Obtaining rootstocks: Select one one-year-old Actinidia kiwifruit seedling and one one-year-old Actinidia kiwifruit seedling as rootstocks. The two rootstocks are required to be strong, free of pests and diseases, with a stem thickness of about 0.5 cm and 2-3 taproots. Prune the taproots of the two rootstocks to a length of 10-15 cm, leaving 4-5 cm of the stem.

[0016] S2. Obtaining scion: Select sturdy branches of the delicious kiwifruit variety (Qinhong) with a thickness of more than 1 cm as scion, with more than one full and complete bud. The scion should be 8 to 12 cm long, the upper end should be sealed with wax or wound healing agent, and the lower end should be cut into a smooth surface.

[0017] S3. Grafting: The kiwifruit seedling grafted body is formed by cleft grafting, as follows: first, the upper ends of the stock stems are cut into 2-3 cm long wedge-shaped slopes on both sides; then, a cleft knife is used to gently split a 2.5-3.5 cm long cleft vertically from the center of the lower end of the scion; finally, the two cut stock are quickly inserted, leaving 0.1-0.2 cm of the stock cut surface outside to facilitate healing. The two stock are placed close to both sides of the scion, so that the cambium of the scion and the stock are aligned, and the grafted part is wrapped with a grafting film to form the kiwifruit seedling grafted body.

[0018] S4. Cultivate grafted seedlings: Arrange the grafted kiwifruit seedlings neatly on the seedbed with the scion facing downward and the root system facing upward; then cover with 2 cm thick fine sand, spray water at appropriate times to keep the sand layer moist, and heal for 18 days. Then place them in the nursery for cultivation. After germination during the cultivation process, remove the buds of the rootstock in time to ensure the healthy growth of the scion buds; after the grafted part heals, remove the grafting film in time, and finally move them into the field for planting.

[0019] Example 2 This embodiment provides a method for cultivating double-root kiwifruit grafted seedlings, the steps and methods of which are basically the same as those of Embodiment 1, except that the grafting in step S3 is replaced by bark grafting, and the rest remain unchanged. When the grafting is performed by bark grafting, the specific steps are as follows: First, cut the upper end of the stock stem into a 2-3 cm bevel surface, with the top sharpened and the surface made thin; then cut a small bevel with a width of 0.2 cm and a length of 1.5-2 cm on both sides of the incision, and cut a small bevel with a width of 0.2 cm on the upper end of the back; then cut a vertical cut in the cortex from both sides of the lower end of the scion, 2-3 cm long and deep into the xylem; finally, put the cut surfaces of the two stockpiles facing the xylem of the scion, and insert them downward close to the xylem, so that the stock is between the xylem and cortex of the scion, and the inner sides of the bark on both sides cover the two wounds of the stock. The upper end of the stock is slightly exposed to white to facilitate healing. After inserting the stock, it is immediately tied tightly with a grafting film to form a kiwi seedling grafted body.

[0020] Comparative Example 1 This comparative example provides a method for cultivating double-root kiwifruit grafted seedlings, and its steps and methods are basically the same as those in Example 1, except that: in step S1, both rootstocks are selected from Actinidia chinensis, and the rest remain unchanged.

[0021] Comparative Example 2 This comparative example provides a method for cultivating double-root kiwifruit grafted seedlings, and its steps and methods are basically the same as those in Example 2, except that: in step S1, both rootstocks are selected from Actinidia chinensis, and the rest remain unchanged.

[0022] Furthermore, in order to understand the differences in the growth of the grafted seedlings and the fruit quality formed in the above-mentioned embodiments and comparative examples, the following statistics were also conducted.

[0023] Table 1 Growth of kiwifruit plants grafted on different rootstocks

[0024] The results in Table 1 show that compared with the Qinhong grafted with two kiwifruit rootstocks, the grafted seedlings of Qinhong grafted with two kiwifruit rootstocks had a better survival rate (up to 93.3-93.7%), faster plant growth and stronger plants (the trunk diameter reached 3.02-3.11 cm after three years), and significantly improved germination rate (71.6-72.2%), branching rate (78.2-78.6%) and fruit setting rate (87.1-88.6). Among them, the cleft grafting method and the bark grafting method had similar effects, and both grafting methods can be well used for double-root kiwifruit grafted seedlings.

[0025] Table 2 Comparison of fruit quality of kiwifruit plants grafted with different rootstocks

[0026] Continued from the table above

[0027] As shown in Table 2, compared with the Qinhong grafted with two kiwifruit rootstocks, the Qinhong grafted with two kiwifruit rootstocks showed an increase in single fruit weight and per mu yield; the dry matter content and main nutrient content of the fruit also increased significantly, among which the phenol content was the most significant (the former was 148.86~150.29mg / 100g, and the latter was 43.97~44.01mg / 100g). Similarly, the results of cleft grafting and bark grafting were comparable, and both grafting methods can be well used for double-root kiwifruit grafted seedlings.

[0028] The specific raw materials not described in the present invention are all existing materials and can be directly purchased from the market; in the embodiments of the present invention, unless otherwise specified, the technical means used are all conventional means well known to those skilled in the art.

[0029] The above are only preferred embodiments of the present invention and are not intended to limit the protection scope of the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for cultivating double-root kiwifruit grafted seedlings, characterized in that: The following steps are involved: S1. Rootstock acquisition: one annual Actinidia kiwifruit and one Actinidia deliciosa seedling were selected as rootstocks, and the taproots of the two rootstocks were trimmed to a length of 10-15 cm, leaving 4-5 cm of stems; S2. Scion acquisition: Select branches of Actinidia selegans as scions. The scions are 8 to 12 cm long, the upper end is sealed with wax or wound healing agent, and the lower end is cut into a smooth surface. S3. Grafting: using the method of bark grafting or cleft grafting, two rootstocks are reversely grafted onto the lower end of the same scion, and the grafted part is wrapped with a grafting film to form a kiwi seedling grafted body; S4. Cultivating grafted seedlings: Cultivate the grafted grafts in a nursery, and transplant them into the field for planting after the grafting sites have healed.

2. The method according to claim 1, characterized in that The stock has a stem thickness of 0.4-0.6 cm and has 2-3 main roots; the scion has a stem thickness of more than 1 cm and has more than one full and complete bud.

3. The method according to claim 1, characterized in that When grafting is done by bark grafting, the details are as follows: First, cut the upper end of the stock stem into a 2-3 cm bevel surface, with the top sharpened and the surface made thin; then cut a small bevel with a width of 0.2 cm and a length of 1.5-2 cm on both sides of the incision, and cut a small bevel with a width of 0.2 cm on the upper end of the back; then cut a vertical cut in the cortex from both sides of the lower end of the scion, 2-3 cm long and deep into the xylem; finally, put the cut surfaces of the two stockpiles facing the xylem of the scion, and insert them downward close to the xylem, so that the stock is between the xylem and cortex of the scion, and the inner sides of the bark on both sides cover the two wounds of the stock, and the upper end of the stock is exposed white to facilitate healing. After inserting the stock, it can be tightly tied with grafting film immediately.

4. The method according to claim 1, characterized in that: When cleft grafting is used, the details are as follows: First, cut both sides of the upper end of the rootstock stem into a 2-3 cm long wedge-shaped slope; then use a cleaving knife to vertically split a 2.5-3.5 cm long cleft from the center of the lower end of the scion; finally, quickly insert the two cut rootstocks, leaving 0.1-0.2 cm of the cut surface of the rootstock outside to facilitate healing. Place the two rootstocks close to both sides of the scion, align the cambium of the scion and the rootstock, and wrap the grafting site with a grafting film.

5. The method according to claim 1, characterized in that Before entering the nursery for cultivation, indoor wound healing is also carried out, as follows: place the scion downward and the root system upward, and arrange them neatly on the seedbed; then cover with 2 cm thick fine sand, spray water at appropriate times to keep the sand layer moist, and let heal for 15 to 20 days.

6. The method according to claim 1, characterized in that During the cultivation process, after germination, the buds from the rootstock should be removed in time to ensure the healthy growth of the scion buds; after the grafted site heals, the grafting film should be removed in time.

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