Camellia oleifera autumn promoting autumn grafting and fast seedling budding grafting method

Abstract

The application provides a camellia oleifera autumn promotes autumn grafting fast seedling bud seedling grafting method, and belongs to the technical field of plant asexual reproduction.The camellia oleifera autumn promotes autumn grafting fast seedling bud seedling grafting method comprises the following steps: (1) selecting early-maturing camellia oleifera seeds in autumn, removing or breaking the seed coat, spraying a germination agent, sealing and germinating to obtain germinated seeds; (2) transferring the germinated seeds to a rootstock bed, cultivating until the hypocotyl is 7-9 cm long, and obtaining bud seedlings for grafting; (3) selecting camellia oleifera lignified summer shoots or autumn shoots as scions, and using the hypocotyl wedge grafting method to graft in late autumn, and transplanting the grafted seedlings on the same day.The grafting method can improve the survival rate, shorten the seedling cycle by half a year, effectively reduce the germination of rootstock root nematodes during the seedling stage, and effectively reduce the seedling cost.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of oil tea propagation, and particularly relates to a method for autumn promoting autumn grafting and fast seedling of oil tea. BACKGROUND

[0002] Oil tea (Oil-tea camellia) belongs to Theaceae Camellia, and is a kind of plant with high seed oil content and economic value. The main components of fatty acids in tea oil are oleic acid, linoleic acid, linolenic acid, palmitic acid and stearic acid, accounting for more than 97% of the total fatty acids, and the content of unsaturated fatty acids mainly including oleic acid and linoleic acid is more than 90%, which is a high-quality edible oil. Because of its characteristics of being resistant to storage, not easy to rancidity and not containing carcinogenic substances such as aflatoxin, it is known as “liquid gold”.

[0003] Oil tea is a unique woody oil crop in China, and its cultivation history has been more than 2000 years. Developing oil tea industry is of great significance to guarantee national grain and oil safety and optimize edible oil structure. The seedling of oil tea has been using the method of bud grafting for a long time. For example, the application number CN201410467706.9 discloses a method for oil tea bud grafting, which is early summer grafting. The seed of the stock is collected in the autumn of the previous year and is stored in sand for half a year, and then is sowed in the middle or late March to cultivate the stock. The half-lignified spring shoots of the current year are collected in early May to be used as scions for grafting. The grafted seedlings need to be carefully managed for two and a half years to reach the standard of qualified seedlings. Although the method discloses the steps from the cultivation of the stock, the selection of the field, the preparation of the seedbed, the construction of the shading shed, the grafting and the management after the grafting, the seed of the stock is collected in the previous year, and the germination rate of the seed is low due to improper humidity control during the storage process, and the stock is wasted. Moreover, the half-lignified spring shoots can only be used as scions for grafting in summer, and the period suitable for grafting is very limited in some areas in southwest China because the period of half-lignification of the spring shoots is very short. In addition, the grafted seedlings need to be managed in a shading shed because the temperature is too high after the grafting in summer, which results in high cost of seedling management. Furthermore, the cotyledon of the bud seedling needs to be reserved and the grafting is performed on the epicotyl in the traditional method and the method disclosed in the prior art, which makes the epicotyl of the stock germinate a large number of sprouts, and the sprouts need to be repeatedly removed, which is difficult and laborious. If the sprouts are not removed in time, the survival rate and the purity of the seedlings will be significantly reduced. SUMMARY

[0004] The present application aims to provide a method for autumn promoting autumn grafting and fast seedling of oil tea with short period, high efficiency and low cost, so as to make up for the deficiency of the prior art.

[0005] To achieve the above object, the present application provides the following technical solutions.

[0006] The present application provides a method for autumn promoting and autumn grafting of fast-growing seedlings of Camellia oleifera, comprising the following steps:

[0007] (1) In autumn, select early-maturing Camellia oleifera seeds, remove or break the seed coat, spray a germination agent, seal for germination, and obtain germinated seeds;

[0008] (2) Transfer the germinated seeds to a rootstock bed, cultivate until the hypocotyls grow to 7-9 cm, and obtain seedling rootstocks for grafting;

[0009] (3) Select Camellia oleifera lignified summer shoots or autumn shoots as scions, and perform grafting by hypocotyl wedge grafting in late autumn, and transplant the grafted seedlings on the same day.

[0010] Preferably, the early-maturing Camellia oleifera in step (1) is Hanluzi ordinary Camellia oleifera, which matures at the end of September to the beginning of October.

[0011] Preferably, the formula of the germination agent in step (1) is as follows: a citric acid-sodium citrate buffer solution with a pH of 4.5-5.5 and a final concentration of 0.2-0.4 mol / L, containing the following components with a final concentration: 2.5-3.5 mg / L GA3, 0.4-0.6 mg / L ZT, and 30-40 μmol / L melatonin.

[0012] Preferably, the Camellia oleifera seeds are placed on a sterile wet towel or sterile filter paper, sprayed with the germination agent once, then covered with a sterile wet towel or sterile filter paper with the same humidity, and the germination agent is sprayed every 2-3 days during the sealing germination period, the sealing germination time is 5-7 days, the sealing germination temperature is 18-20℃, and the humidity of the wet towel or filter paper is 25-35%.

[0013] Preferably, the hypocotyl length of the germinated seeds in step (2) is 0.4-0.6 cm; the rootstock bed uses fine river sand with a particle size of 1.5-2.5 mm as the substrate, after being transferred to the rootstock bed, the seeds are sprayed with the germination agent once, then covered with 4-6 cm of substrate and black mulch, the temperature is 18-25℃, and the humidity is maintained at 40%-50% for cultivation.

[0014] Preferably, after transplantation in step (3), the grafted seedlings are watered with root-fixing water, and a small greenhouse is built to maintain a relative humidity of 80-85% in the small greenhouse until April of the next year, and the small greenhouse is removed when the seedlings grow to 8-12 cm.

[0015] Preferably, the formula of the transplanting substrate in step (3) is as follows: acid red soil or yellow soil: nutrient soil: composted organic fertilizer: vermiculite = (4-6) : (2-4) : 1 : 1.

[0016] The application collects seed of camellia oleifera rootstock in autumn, and forms robust seedling rootstock in one month through promoting germination treatment, and at the end of autumn, woody summer and autumn shoots are used as scions, and only hypocotyls below the seedling are cut for grafting, so that the survival rate is improved, the seedling period is shortened by half a year, the germination of root sprouts of the rootstock in the seedling stage is effectively reduced, and the seedling cost is effectively reduced.

[0017] The camellia oleifera autumn promoting autumn grafting fast seedling seedling grafting method provided by the application changes the limitation of the original technology of summer grafting, solves the problems of low germination rate of traditional seedling grafting camellia oleifera seed in spring and high summer grafting temperature and increased management cost, and well overcomes the problems of difficult collection of spring scions and short suitable grafting period in the southwest region of China. The method has the characteristics of simple operation, strong practicability, high efficiency and suitability for large-area application, and plays an important role in standardization of camellia oleifera seedling breeding. BRIEF DESCRIPTION OF DRAWINGS

[0018] Figure 1 It is the seed disinfection process in example 1;

[0019] Figure 2 It is the germination state diagram of the control, treatment II and treatment IV seeds in example 1;

[0020] Figure 3 It is the process of transferring the germinated seeds to the root bed, the left figure is seed bed, and the right figure is covering and compaction after sowing;

[0021] Figure 4 It is the process of taking rootstock, grafting and transplanting after grafting in example 1, 1 is taking rootstock, 2-3 is hypocotyl grafting, 4-5 is transplanting of grafted seedlings;

[0022] Figure 5 It is the growth of seedlings after transplanting in example 1, 1-2 is the growth of grafted seedlings for 100 days, 3 is the case of grafted seedlings for 8 months, and 4 is the seedlings for 1 year and a half before being removed from the nursery; DETAILED DESCRIPTION

[0023] The application provides a camellia oleifera autumn promoting autumn grafting fast seedling seedling grafting method, which can improve the survival rate, shorten the seedling period by half a year, effectively reduce the germination of root sprouts of the rootstock in the seedling stage, and effectively reduce the seedling cost.

[0024] The application provides a camellia oleifera autumn promoting autumn grafting fast seedling seedling grafting method, which comprises the following steps:

[0025] (1) selecting early-maturing camellia oleifera seeds in autumn, removing or breaking the seed coat, spraying a germination promoting agent, and sealing and germinating to obtain germinated seeds;

[0026] (2) the germinated seeds are transferred to a bed, and cultivated until the hypocotyls grow to 7-9 cm, to obtain seedling rootstocks for grafting;

[0027] (3) the wood-hardened summer shoots or autumn shoots of the oil tea tree are selected as scions, and the hypocotyls are used for grafting by means of wedge grafting in late autumn, and the grafted seedlings are transplanted on the same day.

[0028] In the present application, the early-maturing oil tea tree in step (1) is Camellia oleifera Abel, which matures at the end of September to the beginning of October, and the sign of maturity is that 1 / 3 of the fruits of the whole plant are cracked.

[0029] In the present application, after the seed coat of the oil tea seed is removed or broken, the seed is soaked in 3% sodium hypochlorite for half an hour and then washed with sterile water for 3-5 times, preferably 3 times, and then placed in a container lined with two layers of sterile wet towels or sterile filter paper, sprayed with a germination agent once, and then covered with two layers of wet towels or sterile filter paper of the same humidity.

[0030] In the present application, the humidity of the sterile wet towel or sterile filter paper is 25-35%, preferably 30%.

[0031] In the present application, the formula of the germination agent in step (1) is: 2.5-3.5 mg / L GA3, 0.4-0.6 mg / L ZT, and 30-40 μmol / L melatonin in a citric acid-sodium citrate buffer with a final concentration of 0.2-0.4 mol / L and a pH of 4.5-5.5, preferably 3 mg / L GA3, 0.5 mg / L ZT, and 35 μmol / L melatonin in a citric acid-sodium citrate buffer with a final concentration of 0.3 mol / L and a pH of 5.

[0032] In the present application, the germination agent is sprayed every 2-3 days, preferably every 2 days, during the sealed germination period, and the spraying only needs to attach a layer of water mist to the surface of the seed. The time for sealed germination is 5-7 days, preferably 6 days, and the temperature for sealed germination is 18-20℃, preferably 20℃.

[0033] In the present application, the length of the radicle of the germinated seed in step (2) is 0.4-0.6 cm, preferably 0.5 cm; the bed uses fine river sand with a particle size of 1.5-2.5 mm, preferably 2 mm, as the substrate, and the substrate is sterilized with carbendazim 800 times and thiophanate-methyl 1000 times before use, and then naturally aired for 15 days, with a humidity of 40%-50%, preferably 45%. After transfer, the germination agent is sprayed again, and then covered with 4-6 cm, preferably 5 cm, of the substrate and black mulch, with a humidity of 40%-50%, preferably 45%, and cultured at 18-25℃, preferably 20℃, for 30 days.

[0034] In the present application, the oil tea wood lignified summer shoots or autumn shoots are selected from early November, and the scion is a vegetative branch without flower buds or with fewer flower buds, which is used immediately, and if it needs to be preserved, half of the leaf area is cut off, wrapped with a wet towel, sealed in a plastic bag, and placed in a 4°C refrigerator. The preservation time should not exceed 5 days.

[0035] In the present application, when grafting, a hypocotyl section of 5-6 cm, preferably 5.5 cm, is taken as the rootstock, and the hypocotyl cotyledon end is longitudinally split in the central transverse section by 0.8-1.2 cm, preferably 1 cm deep; a scion with full axillary buds is selected, which is as thick as the rootstock, and a horizontal cut is made at 0.4-0.6 cm above the axillary bud, preferably 0.5 cm, and a wedge-shaped cut is made at 0.4-0.6 cm below the axillary bud, preferably 0.5 cm, with the wedge face being 1-1.2 cm long, preferably 1.2 cm long, and the wedge-shaped end is inserted into the split cut of the rootstock, and a 1.0 cm wide and 3 cm long aluminum foil is used to tighten and fix it.

[0036] In the present application, after transplanting, the grafted seedlings are watered with enough rooting water, and a small greenhouse is built to maintain a relative humidity of 80-85%, preferably 80%, until April of the next year, and the small greenhouse is removed when the seedlings grow to 8-12 cm, preferably 10 cm.

[0037] In the present application, the transplanting substrate formula in step (3) is: acid red soil or yellow soil: nutrient soil: mature organic fertilizer: vermiculite = (4-6): (2-4): 1: 1, preferably 5:3:1:1.

[0038] The technical solutions provided by the present application will be described in detail below in conjunction with the examples, but they should not be understood as limiting the scope of protection of the present application.

[0039] Example 1

[0040] 1.1 Rootstock seed collection and germination

[0041] In September 2021, early-maturing Hanluzi ordinary oil tea was selected as the rootstock seed in an oil tea base in Tianquan County, Ya'an, Sichuan. In late September, when 1 / 3 of the fruit on the whole plant cracked, the fruit was collected and naturally dried indoors. After 3 days, when the fruit shell completely cracked and the seed was completely separated from the shell, the seed was collected. The seed was placed in a beaker and soaked with 3% sodium hypochlorite for half an hour (as shown in FIG. 1). After disinfection, the seed was washed with distilled water that had been sterilized by high-pressure steam (121°C, 25 min) and naturally cooled for 3 times, and was ready for use. Figure 1

[0042] ​The seeds were divided into 5 treatments with 4 groups of repetitions, namely control group, treatment group I, treatment group II, treatment group III and treatment group IV. 50 treated seeds were randomly selected for each treatment and placed in Petri dishes lined with two layers of sterile filter paper, which had been sterilized by high-pressure steam (121°C, 25 min) and naturally cooled. The relative humidity of the filter paper was strictly controlled at about 30%. The control group was sprayed with a watering can on the surface of the seeds with sterile water. The treatment group I was sprayed with a watering can on the surface of the seeds with a mixed solution of 2 mg / L GA3 and 0.5 mg / L ZT (pH = 5.0, water was used as the solvent, the following treatments also used this solvent). The treatment group II was sprayed with a watering can on the surface of the seeds with a mixed solution of 3 mg / L GA3 and 0.5 mg / L ZT. The treatment group III was sprayed with a watering can on the surface of the seeds with a mixed solution of 5 mg / L GA3 and 0.5 mg / L ZT. The treatment group IV was sprayed with a watering can on the surface of the seeds with a mixed solution of 0.3 mol / L citric acid-sodium citrate buffer (pH = 5.0), 3 mg / L GA3, 0.5 mg / L ZT and 35 μmol / L melatonin. Two layers of sterile filter paper with the same humidity were placed on each treatment, and the Petri dishes were sealed with plastic wrap and placed in an environment at 18-20°C for 6 days of germination. During this period, the treatments were sprayed every 2 days. When spraying the germination agents, only a layer of water mist was allowed to adhere to the surface of the seeds.

[0043] Table 1 Germination status of each group of seeds after 6 days of treatment with different germination agents

[0044]

[0045] As shown in Table 1, in terms of germination time, the seeds of treatment IV germinated more concentratedly and uniformly, with a germination rate of 90% on the fourth day.

[0046] Table 2 Average germination rate of seeds after 6 days of treatment with different germination agents

[0047]

[0048] As shown in Table 2, after the seeds were treated with 3 mg / L GA3 + 0.5 mg / L ZT mixed solution (treatment group II) and 0.3 mol / L citric acid-sodium citrate buffer (pH = 5.0) + 3 mg / L GA3 + 0.5 mg / L ZT + 35 μmol / L melatonin mixed solution (treatment IV), the germination rate was significantly higher than that of the control and other treatments. All seeds in the control group did not germinate after 6 days of treatment. Compared with the two germination agents of treatment II and treatment IV, the germination rate of treatment IV was slightly higher than that of treatment II.

[0049] The 6-day germination status of the control, treatment II and treatment IV seeds is shown inFigure 2 As shown in the table, the seed germination and radicle growth of treatment IV is significantly better than that of treatment II, and the control seed has no germination.

[0050] 1.2 Seedling stock culture

[0051] A seedbed with a width of 1.2 m and a length of 8 m was prepared in a greenhouse. The bottom of the seedbed was leveled and then covered with 15 cm thick fine river sand with a particle size of about 2 mm. The sand was disinfected with 800 times of carbendazim and 1000 times of thiophanate-methyl, and then naturally dried for 15 days. When more than 2 / 3 of the seeds were white and the radicle was about 0.5 cm long, the control, treatment II and treatment IV germinated seeds were evenly laid on the seedbed. The above treatments were evenly sprayed with their respective germination promoters, and then covered with 10 cm thick disinfected fine river sand (as shown in the table), and then covered with black plastic film. The humidity of the seedbed was strictly controlled at 40%-50%. After 30 days of culture at room temperature, the hypocotyl length and thickness of different treatments were counted. The results are shown in Table 3. Figure 3

[0052] Table 3 Growth of seedling stocks of different varieties after 30 days of culture with different germination promoters

[0053]

[0054] As shown in Table 3, after the seed was treated with the germination promoter of treatment IV, the main growth indicators of the seedling and the quality indicators of the stock were significantly higher than those of treatment II, and all the seeds of the control treatment did not germinate after 30 days of sowing. It shows that the germination promoter of treatment IV can effectively promote the growth of seedlings, and short-term culture of more robust seedling stocks.

[0055] 1.3 Autumn seedling stock grafting

[0056] ​In early November 2021, when the hypocotyls of the seedlings of the rootstock were about 8 cm long, the woodiness summer shoots and autumn shoots with less flower buds of the Camellia oleifera variety 'Changlin 3' were collected in the Camellia oleifera base in Tianquan County, Ya'an, Sichuan, as scions. The bud seedling rootstocks that were well cultured were gently taken out from the rootstock culture bed, washed with clean water to remove the surface substrate, and the straight and strong bud seedling rootstocks were selected. The cotyledon and epicotyl were cut off by making a horizontal cut at the hypocotyl near the cotyledon, and the root tip was also cut off. Only the 5-6 cm hypocotyl was retained. A 1 cm deep incision was made in the central longitudinal direction of the horizontal cut surface of the hypocotyl cotyledon end for standby use. The axillary buds of the scions were selected, which were comparable in thickness to the rootstock, and the middle bud body of the scion was full. A horizontal cut was made at a distance of 0.5 cm from the upper part of the axillary bud. Two inclined surfaces were cut at a distance of 0.5 cm from the lower part of the axillary bud, which were perpendicular to the stem side of the axillary bud and had a wedge shape with a wedge surface length of 1.2 cm. Half of the leaf was also cut off. The cut scion was inserted into the incision of the rootstock, and was wrapped tightly with an aluminum foil with a width of 1.0 cm and a length of 3 cm. The grafted seedlings were placed in a container covered with a wet towel to keep them moist, and were transplanted on the same day. The above process is shown in Figure 4 .

[0057] 1.4 Seedling transplanting and seedling stage management

[0058] A seedbed was prepared in advance. The seedbed substrate was acidic red soil or yellow soil original soil (pH = 5.0-5.5): nutrient soil: mature organic fertilizer: vermiculite = 5:3:1:1, which was mixed thoroughly and laid to form a seedbed for use. The grafted seedlings were planted in the prepared seedbed at a plant spacing of 5x5 cm. After transplanting, enough water was poured to fix the roots, and a small arched shed with a width of 1.2 m and a height of 60 cm was built. The shed was sealed around to keep warm and humid. The relative air humidity in the shed was controlled to be more than 80% without regular watering. The shed was removed when the seedlings grew to about 10 cm in length in April of the next year. The seedlings were continued to be cultured. The states of the seedlings cultured for 100 days, 8 months, and one and a half years are shown in Figure 5 .

[0059] At the same time, a traditional grafting method (conventional summer grafting method) was used as a control (CK). The traditional grafting method was as follows: In September 2020, the same year-old wild Camellia oleifera seeds as in Example 1 were collected. After natural air drying, the seeds were directly buried in the rootstock culture bed without treatment with a germination agent, according to the method of Example 1. In mid-May 2021, grafting was performed. The semi-wooded spring shoots of the Camellia oleifera variety 'Changlin 3' were collected in the Camellia oleifera base in Tianquan County, Ya'an, Sichuan, as scions. The other treatments were the same as in Example 1. In October 2022, the growth indexes of CK and treatment IV in Example 1 were counted at the same time.

[0060] From CK and treatment IV in Example 1, 1 m 2Area seedling bed 400 seedlings, statistics CK and the survival of seedlings, the survival rate of grafting, root and rhizome germination quantity (each seedling germination root and rhizome branch number), seedling height and thickness (grafting axillary bud germination branch base thickness). The results are shown in Table 4. Different capital letters represent significant difference, P < 0.01.

[0061] Table 4 Growth of Camellia oleifera seedlings under different seedling raising methods

[0062] Grafting method Survival seedling number Grafting survival rate Average root number Seedling height (cm) Seedling stem diameter (mm) CK 315 78.70％ 4.73±2.14A 26.3±7.36A 2.53±0.36A Autumn promotion autumn grafting 333 83.30％ 0.35±0.08B 25.5±2.13A 2.61±0.11A

[0063] Table 4 compares the growth of seedlings after grafting by the conventional summer seedling raising method and the autumn promoting autumn grafting method of the present application. It can be seen that the grafting survival rate of the method of the present application is slightly higher than that of the traditional method. It is worth noting that in terms of root and rhizome growth, the number of roots of the method of the present application is significantly lower than that of the conventional method. At the same time, under the premise of cultivating the seedlings half a year later than the conventional method, the seedling height and stem thickness cultivated by the method of the present application have no significant difference with the traditional method. It shows that the method of the present application can shorten the seedling raising period by more than half a year, save the cost of seedling raising, and effectively reduce the root sprouting of the rootstock.

[0064] The above is only the preferred embodiment of the present application, it should be noted that for ordinary skilled in the art, without departing from the principles of the present application, can make a number of improvements and refinements, these improvements and refinements should also be considered as the protection scope of the present application.

Claims

1. A method for grafting buds onto Camellia oleifera seedlings to promote rapid seedling growth in autumn, characterized in that... Includes the following steps: (1) Select early-maturing camellia seeds in autumn, remove or break the seed coat, spray with germination promoter, seal and germinate to obtain germinated seeds; (2) Transfer the germinated seeds to a rootstock and cultivate them until the hypocotyl reaches 7 cm in length. 9cm, to obtain a bud rootstock for grafting; (3) Select lignified summer or autumn shoots of Camellia oleifera as scions, and graft them using the hypocotyl cleft grafting method in late autumn. Transplant the grafted seedlings on the same day. The formulation of the sprouting agent mentioned in step (1) is as follows: pH 4.5 5.5, final concentration 0.2 0.4 mol / L citric acid Sodium citrate buffer contains the following final concentration: 2.5 3.5 mg / L GA3, 0.4 0.6 mg / L ZT, 30 40 μmol / L melatonin.

2. The method for grafting Camellia oleifera seedlings to promote rapid seedling growth in autumn according to claim 1, characterized in that, The early-maturing camellia mentioned in step (1) is the common camellia with cold dew seeds, which matures from the end of September to the beginning of October.

3. The method for grafting Camellia oleifera seedlings to promote rapid seedling growth in autumn according to claim 1, characterized in that, The camellia seeds are placed on a sterile damp towel or sterile filter paper, sprayed with the germination promoter once, and then covered with a sterile damp towel or sterile filter paper of the same humidity. During the sealed germination period, this process is repeated every 2 days. Spray the germination promoter once every 3 days, and the sealed germination time is 5 days. The sealed germination temperature was 18°C ​​for 7 days. At 20°C, the humidity of the damp towel or filter paper is 25%. 35%.

4. The method for grafting Camellia oleifera seedlings to promote rapid seedling growth in autumn according to claim 1, characterized in that, The radicle length of the germinated seed in step (2) is 0.4 cm. 0.6cm; the anvil bed uses particles with a diameter of 1.

5. Use 2.5mm fine river sand as a substrate, transfer the seeds to the rootstock, spray the seeds with a germination promoter again, and then cover with 4... 6cm substrate and black mulch, temperature 18 25℃, humidity maintained at 40% 50% are cultured.

5. The method for grafting Camellia oleifera seedlings to promote rapid seedling growth in autumn according to claim 1, characterized in that, After transplanting the grafted seedlings in step (3), water them thoroughly to help them establish roots, and build a small arched shed to maintain a relative humidity of 80% inside. 85%, and by April of the following year, the seedlings had grown to 8... Remove the small arched frame when the height reaches 12cm.

6. The method for grafting Camellia oleifera seedlings to promote rapid seedling growth in autumn according to claim 1, characterized in that... The seedling substrate formula for transplanting described in step (3) is: acidic red or yellow soil: nutrient soil: well-rotted organic fertilizer: vermiculite = (4 6): (2 4):1:1.

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