A method for cultivating kiwi hard-wood cutting seedlings in one step

Abstract

The application discloses a kiwi hard branch cutting one-step seedling cultivation method and relates to the technical field of kiwi production of fruit trees, and comprises the following steps: step 1, cutting preparation; step 2, one-time callus induction; step 3, incision treatment; step 4, secondary callus induction; step 5, pre-cutting treatment; step 6, cutting bed manufacturing; step 7, pre-cutting sterilization; step 8, cutting; step 9, tube protection; and step 10, grafting. The application has the advantages of strong practicability, clear steps, convenient operation and obvious effect, and can effectively solve the problems of low rooting rate and survival rate of the existing cutting breeding, high tissue culture breeding cost, incapability of being widely applied to production practice and the problem of seedling breeding that can only be solved by the method of long-time and low-effect seedling propagation and then grafting.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of kiwifruit production, and particularly relates to a hard branch cutting one-step seedling cultivation method of kiwifruit. BACKGROUND

[0002] The main kiwifruits widely cultivated at present are delicious, Chinese and soft jujube kiwifruits, wherein the Chinese and delicious kiwifruits are the most widely cultivated kiwifruit species in the world, accounting for more than 80% of the total cultivation area, and the soft jujube and opposite calyx kiwifruits have a higher rooting rate of hard branch cutting, while the Chinese and delicious kiwifruits have a very low rooting rate. The delicious kiwifruit seedling has many advantages such as luxuriant root system, strong stress resistance, wide adaptability, good graft compatibility and the like, so more than 90% of the delicious kiwifruit is used as a stock in production. Due to the limitation of propagation technology, the main method for seedling and garden construction at present is still grafting of the cultivation variety on the seedling of the delicious kiwifruit.

[0003] There are four propagation methods of kiwifruit, namely seedling propagation, grafting propagation, tissue culture propagation and cutting propagation, wherein the seed and grafting methods are the most commonly used propagation methods at present. However, the seed propagation is sexual reproduction, and although the survival rate and seedling rate are high, the seeds are all hybrid bodies, the offspring has certain genetic segregation phenomenon, and there is more or less difference between the propagated seedlings, which is an important reason for the uneven garden.

[0004] The grafting of seedling propagation has certain requirements for the thickness and health degree of the stock, and the diameter of the stock seedling generally needs to reach 0.7 cm or more for grafting. The stock seedling of seedling propagation needs to be transplanted multiple times from sowing to grafting, and at least needs to be cultivated for more than 3 years to reach the requirement of large seedling grafting. After grafting in the third year, the seedling needs to be cultivated for another year before being put on the shelf, and only then the seedling can be put on the shelf after nearly 4 years of careful cultivation. The seedling can bear fruit in the fifth year, which consumes a lot of time and labor. Even if the stock seedling is purchased for grafting to build a garden, although the cost of stock seedling cultivation for 3 years is saved, a large number of seedlings need to be purchased for building a garden, which increases the economic cost of field building. In addition, due to the string exchange of scions between different places during grafting, a series of problems such as disease and insect pests, degeneration of species and the like occur, and the innate differences between the stocks directly lead to the differences in growth potential, stress resistance, fruit quality, preservation of rare and excellent resource species and the like of the seedlings cultivated by grafting, especially the great influence on the color of the flesh of red and yellow heart kiwifruit. This has been the biggest obstacle to the standardization of kiwifruit production.

[0005] The tissue culture method has high seedling raising cost, strict requirements for the period of taking external organs and sterilization, needs professional training for operation, and also needs to be equipped with operation room and light culture room. The test tube seedlings need to be expanded, rooted, indoor seedling training, and transplanted out of the bottle, and other complicated procedures. In order to improve the survival rate of transplanting, it is necessary to cultivate in a greenhouse facility. After transplanting and survival, it takes 2-3 years to cultivate into a large seedling. At present, the tissue culture method is mainly applied to the cultivation of virus-free seedlings and the preservation of rare resources.

[0006] The kiwi cutting propagation method is a method of directly cutting and rooting the one-year-old branches of the mother plant to breed seedlings, which belongs to asexual reproduction. The method has the characteristics of stable genetic mother generation, short seedling raising period, fast planting speed, and low garden building cost. At present, the cutting propagation method is widely used for soft jujube and Actinidia polygama, but there are few reports on the successful and large-scale application of the cutting propagation method for delicious kiwi. The main reason is that the cutting root is difficult, and the survival rate is less than 10%. At present, the old method of grafting varieties after breeding seedlings by seed propagation of large stock seedlings is still used in production. The seedling cultivation not only needs multiple transplanting, but also has poor uniformity after garden building. SUMMARY

[0007] The purpose of the present application is to provide a kiwi hardwood cutting one-step seedling cultivation method to solve the problems of low rooting rate and survival rate in the existing cutting propagation, high cost of tissue culture propagation, and inability to be widely applied to production practice. The problem of seedling cultivation can only be solved by the method of seed propagation with long time consumption and poor effect.

[0008] To achieve the above purpose, the present application provides a kiwi hardwood cutting one-step seedling cultivation method, which comprises the following steps:

[0009] Step 1: cutting preparation

[0010] Step 2: one-time callus induction

[0011] The lower end of the cutting in step 1 is buried in the sand pile with the morphology upward to promote the repair tissue to be generated at both ends of the morphology cut;

[0012] Step 3: incision treatment

[0013] After the white repair tissue generated at the base of the cutting in step 2 is removed, the cutting is vertically cut at the base with a knife;

[0014] Step 4: secondary callus induction

[0015] The cutting treated in step 3 is wrapped with a transparent plastic bag and placed in the open field for 0.5-2 hours, buried in river sand, and then covered with wet sand. The secondary callus is generated within half a month in the open field.

[0016] Step 5: Pre-insertion treatment

[0017] The cuttings in step 4 are removed and the base of the cutting is soaked in constant temperature water at 35±3℃, then rinsed with clean water, and the lower end of the cutting is soaked in the mixed solution;

[0018] Step 6: Preparation of the cutting bed

[0019] The bottom of the cutting bed is a structure with a high middle and low sides, and the upper part of the cutting bed is covered with a transparent film;

[0020] Step 7: Pre-insertion disinfection

[0021] The base of the cutting treated in step 5 is soaked and drained, and then the cutting is prepared;

[0022] Step 8: Cutting

[0023] Black film is covered on the cutting bed in step 6, and the cutting in step 7 is inserted into the hole on the black film;

[0024] Step 9: Tube protection

[0025] It includes tube protection before germination, tube protection after germination, tube protection after rooting, and tube protection in July and later;

[0026] Step 10: Grafting

[0027] In the spring of the second year before germination, a 5-10 cm flat cut is made at the base of the newly grown annual branch, or grafting is performed on the cutting of the cutting seedling.

[0028] Further, the thickness of the lower end of the branch in step 1 is 0.7-1.0 cm.

[0029] Further, in step 4, the humidity of the river sand is 50%, and the depth of the wet sand is 10 cm.

[0030] Further, in step 5, the cutting base is soaked for 30 minutes, and the mixed solution includes 0.05 mg / L vitamin B1, 0.05 mg / L vitamin B6, 50 mg / L chitin, and NAA 0.02 mg / L.

[0031] Further, in step 6, the cutting bed is set up in three layers, including the surface layer, the middle layer and the bottom layer of the cutting bed, the surface layer is river sand, perlite or vermiculite layer, the thickness is 15-20 cm, the middle layer is the substrate layer, the thickness is 15±5 cm, and the bottom layer of the cutting bed is the garden surface layer of mature soil.

[0032] Further, in step 7, the base of the cutting is soaked in a 400-fold solution of 25% carbendazim wettable powder.

[0033] Further, the cutting in step 8 adopts a three-factor two-level orthogonal design.

[0034] Compared with the prior art, the present application has the following advantages:

[0035] 1. The rooting rate and survival rate of the cuttings are improved, and the seedling rate is as high as 90% or more;

[0036] 2. Since the cutting propagation is asexual reproduction, the consistency of the offspring characteristics is high, which is beneficial to standardized garden construction and large-scale production, and fundamentally improves the quality and grade of the orchard;

[0037] 3. In the selection of disease-resistant rootstocks, the preservation and large-scale application of excellent germplasm, the offspring have a high degree of consistency, which is a significant advantage;

[0038] 4. The expansion and large-scale application of excellent varieties are outstanding;

[0039] 5. When grafting, the grafting is directly performed on the rooted and survived cuttings, and the thickness of the cuttings can reach the grafting thickness requirement in the same year. Compared with the seedling method, the grafting method saves more than 2 years of seedling time, reduces the construction cost, and shortens the construction period;

[0040] 6. Through the one-step seedling cultivation method, the introduction of original seeds establishes a budding orchard, avoiding the risk of spreading of devastating diseases such as ulcer disease through grafting;

[0041] 7. The one-step seedling method can realize the large-scale cutting of the delicious kiwifruit variety Cuxiang, and can quickly realize the large-scale application of grafting and species replacement;

[0042] 8. The one-step seedling method is a propagation method with stable genetic mother characteristics, which has the advantages of fast seedling speed, low construction cost, and early production of orchard. BRIEF DESCRIPTION OF DRAWINGS

[0043] Figure 1 Figure 1 is a diagram of callus induction for cuttings;

[0044] Figure 2 Figure 2 is a diagram of a greenhouse for cutting;

[0045] Figure 3 Figure 3 is a diagram of the second callus induction;

[0046] Figure 4 Figure 4 is a diagram of removing the branch pith after cutting callus;

[0047] Figure 5 Figure 5 is a diagram of substrate proportioning;

[0048] Figure 6 Figure 6 is a diagram of germination after cutting;

[0049] Figure 7 Figure for sprouting of cuttings;

[0050] Figure 8 Figure for 45 days after sprouting of cuttings;

[0051] Figure 9 Figure for 60 days after sprouting of cuttings;

[0052] Figure 10 Figure for newly germinated root;

[0053] Figure 11 Figure for flourishing new root;

[0054] Figure 12 Figure for root system and main vine growth of cuttings in the same year;

[0055] Figure 13 Figure for developed main root and lateral root of cuttings. DETAILED DESCRIPTION

[0056] The technical solutions in the embodiments of the present application will be described clearly and completely below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0057] As shown in Figures 1-13 the present embodiment, the kiwi hardwood cutting one-step seedling cultivation method comprises the following steps:

[0058] Step 1: cutting preparation

[0059] The one-year-old branches of the Cui Xiang variety are used as cuttings, and the mother plants for the cuttings do not use chemical fertilizers, but only use composted manure. In mid-June, some branches are selected from the fruiting mother branches on the periphery of the crown, and are marked. The branches are pinched in time when they grow to 1.5 meters. In December, in combination with the winter pruning of kiwi, the branches are selected from the middle and lower ends, the thickness is 0.7-1.0 cm, the lignification intensity is high, the epidermis is dark brown, the bud body is obvious, and there is no disease and insect damage. The branches are cut into branch segments with 3-4 buds and a length of about 15-25 cm. When the cuttings are pruned, the opposite side of the cutting base is beveled at 0.5 cm from the lower bud, and the top of the cutting is flat cut at 2-3 cm from the bud. After cutting, the pith of the lower end of the cutting is removed to a depth of 1 cm.

[0060] Step 2: one-time callus induction

[0061] The morphological lower end and upper end of the cutting in step 1 are arranged in order and bundled into small bundles of about 20, and in December to mid-February, the morphological lower end is buried in a sand pile with a cover depth of 10 cm of wet sand, and is stored in wet sand with a humidity of 50% for 45-80 days, and the cutting with induced roots is timely cut in advance according to step 8.

[0062] Step 3: Wound treatment

[0063] After the white repair tissue generated at the base of the cutting in step 2 is removed, 2 cuts are made on the bark of the cutting base 2 cm long and deep into the xylem, to promote rooting.

[0064] Step 4: Secondary callus induction

[0065] The cutting after step 3 is wrapped with a transparent plastic bag and placed in the open field for 0.5-2 hours, and is buried in river sand with a humidity of 50%, and is covered with 10 cm of wet sand, and secondary callus is induced within half a month. The present application induces callus from the cut twice, and removes the first and second callus, which slows down the path of the cutting through callus to quickly absorb water and nutrients from the substrate before rooting, and delays the supply speed of water and nutrients required for germination and stem and leaf growth, which plays a key role in cutting rooting and survival.

[0066] Step 5: Pre-cutting treatment

[0067] The cut secondary callus in step 4 is removed, the cutting base 5 cm range is soaked in constant temperature water at 35±3℃ for 2-3h, the cutting base is rinsed with water for 3-5 minutes, and the lower end 3 cm of the cutting is soaked in a mixture of 0.05mg / L vitamin B1, 0.05mg / L vitamin B6, 50mg / L chitin and NAA0.02mg / L for 12 hours.

[0068] Step 6: Preparation of cutting bed

[0069] The cutting bed is located in the greenhouse, the bottom of the cutting bed is made into a steamed bun-shaped structure with high in the middle and low on both sides, which is convenient for excess water to seep out, and the bed surface can also be made into a convex double-ridge seedling pool with a slope, the soil is compacted and the surrounding is brick-laid into a hollow shape, the cutting bed is disinfected by spraying 0.3-0.5% potassium permanganate, and is equipped with a humidifying micro-sprinkler about 60 cm high from the bed surface, each cutting is equipped with a drip irrigation pipe for substrate humidification, water replenishment and cooling, and a bamboo arch is made on the top of the cutting bed, which is covered with a transparent film for heat preservation.

[0070] The cutting bed is composed of stratified substrates, which is divided into three layers, namely the surface layer, the middle layer and the bottom layer of the cutting bed. The surface layer is a layer of river sand, perlite or vermiculite, with a thickness of 15±5 cm, which is used for cutting cuttings. The middle layer is a substrate layer, which provides nutrients for root growth, with a thickness of 15±5 cm. The surface layer substrate is laid on the cutting bed or separately packed in a seedling bag. The middle layer substrate is a substrate that has been sterilized at high temperature and passed through a 4-mesh sieve. The volume ratio of the substrate is 1 part of rotten leaf soil: 1 part of river sand: 1 part of paddy soil. The bottom layer of the cutting bed is a garden surface layer of mature soil.

[0071] Step 7: Disinfection before cutting

[0072] Before cutting, immerse the base of the cuttings in a 400-fold solution of 25% carbendazim wettable powder for 5-8 minutes, then drain the excess water and dry. After drying, prepare for cutting.

[0073] Step 8: Cutting

[0074] The cutting density is wide and narrow row cutting, or single row cutting. The upper part of the cutting is left with one bud exposed, and the rest is planted in the substrate. Finally, close the cut end.

[0075] Cutting period: 20-30 days before the Qingming Festival, about 1 month before the night temperature stabilizes above 3-5°C.

[0076] Cutting method: One day before cutting, pour the surface layer of river sand with IBA 1.0-1.5 mg / L solution to ensure that the substrate moisture content is about 50% during cutting. Cover the cutting bed with a layer of black film to prevent weed growth. Wide and narrow row cutting method: large row spacing 30-40 cm, small row spacing 5-10 cm, plant spacing 3-8 cm high density cutting, planting depth 10-15 cm. Single row cutting method: row spacing 15-20 cm, plant spacing 3-8 cm high density cutting, planting depth 10-15 cm. Before cutting, use a wooden stick to pre-insert a hole in the black film, then insert the cutting in the hole. After cutting, ensure that one bud is exposed on the cutting. Immediately after cutting, compact the substrate around the cutting, and apply sealant to the top of the cutting.

[0077] Cutting backup: An additional amount of 1 / 5 of the total number of cuttings is prepared according to the above steps 1-7, which is used to replace the cuttings that do not germinate in the cutting bed.

[0078] In order to achieve the best cutting rooting effect, multiple tests were conducted to screen out the combination of hormones, cutting node number and substrate type. The test is as follows:

[0079] Hardwood cutting adopts three-factor two-level orthogonal design L4(2 3 ):

[0080] 1. A1B1C1, 2. A1B2C2, 3. A2B1C2, 4. A2B2C1.

[0081] A. Hormone type:

[0082] Formula A1: 0.05 mg / L of vitamin B1, 0.05 mg / L of vitamin B6, 50 mg / L of chitin, and 0.02 mg / L of NAA in a mixed solution for 12 hours.

[0083] Formula A2: Rooting agent, active ingredients: IBA 0.5 mg / L and 6-BA 0.06 mg / L.

[0084] B. Number of nodes of cuttings:

[0085] B1: 2 nodes, length 10-15 cm; B2: 3 nodes, length 18-30 cm.

[0086] C. Substrate type:

[0087] C1: 100% rotten leaf soil.

[0088] C2: 100% wet sand on the top, mixed substrate on the bottom, mixed substrate ratio: 40% rotten leaf soil: river sand: paddy soil (substrate with 4-mesh screen) 1:1:1 substrate one and 40% rotten leaf soil substrate two.

[0089]

[0090] Rooting: The germination rate of cuttings is averaged at more than 95%, and the rooting rate is in the order of treatment 2 > treatment 1 > treatment 4 > treatment 3, wherein the average rooting rate of treatment 2 is 90%, significantly higher than that of other treatment groups, the average rooting rate of treatment 1 is 69%, only second to that of treatment 2, the average rooting rate of treatment 4 is 68%, higher than that of treatment 3, the average rooting rate of treatment 2 and treatment 1 treated with hormone formula 1 is significantly higher than that of treatment 3 and treatment 4 treated with hormone formula 2, the rooting rates of treatment 2 and treatment 4 with three nodes are 90% and 68% respectively, indicating that the length of nodes also has a certain effect on improving the rooting rate, and the statistical root length shows that the number of root systems with a length of more than 2 cm in treatment 1 is more than 10, which is the most vigorous treatment group in different treatment groups.

[0091] Step 9: Management

[0092] a. Management after cutting until germination: cover the greenhouse and arched shed film, the substrate is sufficient in water, the temperature is relatively low, the light is relatively weak, the cutting bed can not be shaded, and irrigation with clear water is good.

[0093] b. Post germination care: As the temperature gradually rises, the cuttings begin to germinate. During this period, the substrate moisture should be kept adequate, keeping the soil humidity at about 60%. Cover the bed with 50-75% shading net. Open the micro-sprinkler for 0.5-2 minutes at 10 am and 3 pm every day, and every 5-7 days, spray 0.01 g / L of 25% wettable powder of carbendazim, check the germination, replace the dried or ungerminated cuttings with backup cuttings in time to ensure uniform germination. When the germination rate reaches more than 70%, provide shade to prevent sunburn, except for receiving sunlight in the morning and evening, the shading should be more than 75% from 11 am to 3 pm. When the temperature in the greenhouse exceeds 35°C, gradually open one corner of the greenhouse to ventilate and cool down. When the temperature in the greenhouse is lower than 28°C, close the ventilation port.

[0094] c. Post-rooting care: From late May to late June, the cuttings root heavily, and the new shoots grow rapidly. Use a thin rope to guide the new shoots vertically upward. Open the shading net fully to receive light before 9 am and after 5 pm every day. Open the micro-sprinkler for 0.5-2 minutes every day, and every 3-7 days, drip irrigation according to the soil moisture content, keeping the soil moisture content at 50-60%. Check the rooting regularly, and every 7-10 days after rooting, spray nutrient solution once, the nutrient solution formula is: biological bacteria fertilizer 1 mg / L, trace element fertilizer 3-5 g / L, and 0.01 g / L of 25% wettable powder of carbendazim. Spray thoroughly each time. When the air temperature in the greenhouse exceeds 38°C after ventilation, gradually remove the greenhouse film and the greenhouse film.

[0095] d. Care in July and later: Most of the main vines are longer than 0.3 meters, gradually remove the film above the bed, the greenhouse film, and the shading net. Every 7-10 days, drip irrigation and fertilization. The fertilizer formula is: per square meter, spread urea 10-15 g, magnesium sulfate 5 g, ferrous sulfate 1 g, potassium dihydrogen phosphate 5 g, and ammonium fulvic acid 2 g. Gradually increase the fertilizer amount, and according to the substrate humidity, spray water 1-3 times a week, and control diseases and pests in time. Guide the main vines vertically upward, and when the main vines reach 0.6-1.0 m in length, pinch the top. After the secondary shoots germinate, leave 10 cm and pinch the top repeatedly to promote the growth of the main vines. The diameter of the seedlings can reach 0.6-1.2 cm in the fall.

[0096] Step 10: Grafting

[0097] Apply the cutting variety Cui Xiang directly to build a garden. In the spring of the second year, continue to guide the newly grown one-year-old branches to the upper shelf to cultivate the main vines. In the same year, multiple main branches can be cultivated. Alternatively, leave the newly grown one-year-old branches 5-10 cm long for short cutting, and after the base buds germinate, leave a healthy new shoot to cultivate the main vines again. Both methods require strengthening of fertilization and water, good control of diseases and pests, and good guidance of the new shoots upward and pruning work. In the same year, the upper shelf cultivation of the main vines and the main shoots can be completed, and fruiting can be achieved in the third year.

[0098] If other varieties are to be changed, such as delicious kiwifruit, Chinese kiwifruit and soft jujube kiwifruit, 5-10 cm flat cut can be left at the base of the new annual branch before budding in spring of the second year, and grafting can also be done on the cutting of the cutting seedling, and new seedlings are cultivated to build a garden.

[0099] While embodiments of the application have been shown and described, it is to be understood that the embodiments described are merely divergences, modifications, replacements and variations of the embodiments, and the scope of the application is defined by the appended claims and their equivalents.

Claims

1. A one-step method for cultivating kiwifruit seedlings from hardwood cuttings, characterized by: The method comprises the following steps: Step 1: cutting preparation Step 2: primary callus induction The cutting in step 1 is buried in a sand pile with the morphological lower end upward, so as to promote the generation of repair tissues at both ends of the morphological cut; Step 3: wound treatment After the white repair tissues generated at the base of the cutting in step 2 are removed, the base of the cutting is vertically incised with a knife; Step 4: secondary callus induction The cutting treated in step 3 is wrapped with a transparent plastic bag and placed in an open field for airing for 0.5-2 hours, is then buried in river sand, and is finally covered with wet sand, so as to promote the generation of secondary callus within half a month in the open field; Step 5: pre-insertion treatment The cutting in step 4 is subjected to the following treatments: the cut is removed, the base of the cutting is soaked in water at a constant temperature of 35±3 DEG C, is then rinsed with water, and is finally soaked in a mixed solution including 0.05 mg / L vitamin B1, 0.05 mg / L vitamin B6, 50 mg / L chitin and 0.02 mg / L NAA; Step 6: preparation of an insertion bed The bottom of the insertion bed is a structure with a middle part being higher and both sides being lower, the upper part of the insertion bed is covered with a transparent film, and the insertion bed is provided with three layers, i.e., a surface layer, a middle layer and a bottom layer, the surface layer is a layer of river sand, perlite or vermiculite with a thickness of 15±5 cm, the middle layer is a substrate layer, the volume ratio of the substrate layer is 1 part of rotten leaf soil: 1 part of river sand: 1 part of paddy field soil, and the bottom layer is a layer of garden surface mature soil with a thickness of 15±5 cm; Step 7: pre-insertion sterilization The base of the cutting treated in step 5 is soaked and then is prepared for cutting; Step 8: cutting The cutting is inserted into a hole in a black film covering the insertion bed in step 6; Step 9: tube protection The tube protection comprises pre-insertion tube protection, post-emergence tube protection, post-rooting tube protection and tube protection in July and later stages; Step 10: grafting Grafting is performed on the base of a newly generated annual branch with a flat cut of 5-10 cm in length in spring before the branch sprouts in the second year, or grafting is performed on the cutting of the cutting seedling.

2. The method according to claim 1, wherein the method is characterized by: The thickness of the lower end of the branch in step 1 is 0.7-1.0 cm.

3. The method according to claim 1, wherein the method is characterized by: The humidity of the river sand in step 4 is 50%, and the depth of the wet sand is 10 cm.

4. The method according to claim 1, wherein the method is characterized by: The base of the cutting in step 7 is soaked in a 400-fold solution of 25% carbendazim wettable powder.

5. The method according to claim 1, wherein the method is characterized by: The cutting in step 8 is designed by using a three-factor two-level orthogonal method.

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