A method for inducing plants to return to their juvenile stage

Abstract

This invention belongs to the field of plant cultivation technology, specifically relating to a method for inducing plants to return to their juvenile stage. The invention provides a method for inducing plants to return to their juvenile stage, comprising the following steps: S1, pre-treating plant stem segments, then inducing root growth under strong light to obtain new shoots; S2, subjecting the new shoots to low-light acclimatization to obtain juvenile plants; the low-light acclimatization process is accompanied by topping. By combining low-light acclimatization with topping to remove apical dominance, inhibiting excessive upward growth, promoting lateral bud sprouting and branching, reducing nutrient consumption by the mature apical tissue, and allowing more nutrients to be supplied to the tender parts, further strengthening the juvenile growth of the plant, thereby obtaining plants that have returned to their juvenile stage. Therefore, the technical solution provided by this invention not only enables the preparation of sterile seedlings, improving seedling quality; but also, after tissue culture of these sterile seedlings, it helps to improve the efficiency of plant tissue culture, providing guidance for the standardized cultivation of corresponding plants.

Description

Technical Field

[0001] This invention belongs to the field of plant cultivation technology, specifically relating to a method for inducing plants to return to their juvenile stage. Background Technology

[0002] Dragon fruit belongs to the genus *Hylocereus* of the cactus family (Cactaceae). Hylocereus The fruit of a perennial climbing succulent shrub; the common species is the white-fleshed dragon fruit. Hylocereus undatus Red-fleshed dragon fruit Hylocereus costaricensis Yellow-fleshed dragon fruit Hylocereus megalanthus Dragon fruit, originally from Central America, is now widely cultivated in southern my country and tropical regions. The fruit is rich in anthocyanins, dietary fiber, and various minerals; its flesh is sweet and nutritious, making it suitable for both fresh consumption and processing. The plant is highly adaptable, drought-tolerant, and can thrive in poor soil, bearing fruit multiple times a year, resulting in stable economic benefits. Therefore, dragon fruit cultivation not only effectively increases farmers' income but also significantly contributes to enriching fruit supply, enhancing the competitiveness of agricultural products, and promoting the modernization of high-efficiency tropical agriculture.

[0003] High-quality seedlings are the core foundation for the large-scale cultivation of dragon fruit, and tissue culture is the mainstream technology for propagating high-quality seedlings. Current techniques often use mature stem segments of dragon fruit as explants for tissue culture, but this has significant drawbacks: First, mature tissues are physiologically older, with weaker dedifferentiation and redifferentiation capabilities, significantly increasing the difficulty of inducing callus and adventitious buds, prolonging the culture cycle, and resulting in a low proliferation coefficient, making it difficult to meet the demands of efficient propagation. Second, mature stem segments carry a large number of endophytic bacteria and other microorganisms, making sterilization extremely difficult and prone to contamination during culture, directly leading to tissue culture failure. Third, mature tissues easily accumulate viral pathogens, resulting in a high rate of virus-carrying seedlings, which can easily lead to varietal degeneration, weak plant growth, and other problems, failing to guarantee the uniformity of seedling quality, thus hindering the advancement of large-scale and standardized dragon fruit cultivation. Therefore, if dragon fruit could be induced to return to its juvenile stage, and the resulting sterile seedlings were used for tissue culture propagation, it would not only accelerate the efficiency of tissue culture propagation but also greatly promote the standardized cultivation of dragon fruit. Summary of the Invention

[0004] The purpose of this invention is to provide a method for inducing plants to return to their juvenile stage, thereby obtaining sterile seedlings that are beneficial to improving tissue culture efficiency.

[0005] This invention provides a method for inducing plants to return to their juvenile stage, comprising the following steps: S1. Pre-treat the plant stem segments, then induce root growth under strong light to obtain new shoots; S2. The new shoots are subjected to low light acclimatization to obtain plants in their juvenile stage; the low light acclimatization process is accompanied by topping treatment; The plant in question is dragon fruit; In step S2, when the new shoots grow to 1-2cm, they are subjected to low light acclimatization. The light intensity for low light acclimatization is 1500-3000 lux, the light duration is 14-16h / d, and the air humidity is 70%-85%. The temperature during light is 25-30℃, and the temperature during darkness is 20-24℃. In step S2, the low-light acclimatization ends when the areoles of the branches are velvety and do not contain erect thorns. In step S2, each time the topping treatment is performed, the new branches that have grown to 4-10cm are the targets for topping. The branches are cut flat 2-6 buds away from the base of the new branches to remove the top of the new branches.

[0006] Preferably, the dragon fruit varieties include one or more of JTB32, Thornless Red, and Golden Dragon.

[0007] Preferably, in step S1, the pretreatment method includes: ventilating and drying the wounds on the stem segment, immersing and disinfecting the base of the stem segment, and then drying it to obtain the pretreated stem segment; The stem segment is 4-10 cm long and contains 3-4 complete buds; The base of the stem segment is the base after oblique cutting.

[0008] Preferably, in step S1, the light intensity of the strong light is 6000-8000 Lux; during the induction of rooting, the air humidity is 80%-90%, the light duration is 12-16 h / d; the temperature during light is 26-28℃, and the temperature during darkness is 20-24℃.

[0009] This invention provides the application of the method described in the above technical solution in improving the efficiency of dragon fruit tissue culture and / or preparing sterile dragon fruit seedlings.

[0010] Beneficial effects: This invention provides a method for inducing plants to return to their juvenile stage, comprising the following steps: S1, pre-treating plant stem segments and then inducing root growth under strong light to obtain new shoots; S2, subjecting the new shoots to low-light acclimatization to obtain plants in their juvenile stage; the low-light acclimatization process includes topping; the plant is dragon fruit; in step S2, when the new shoots grow to 1-2 cm, low-light acclimatization is performed, and the light intensity for low-light acclimatization is 1500-3000 ppm. The light exposure duration is 14-16 hours / day, and the air humidity is 70%-85%. The temperature during light exposure is 25-30°C, and the temperature during darkness is 20-24°C. In step S2, the low light acclimatization ends when the areoles of the branches are velvety and do not contain upright thorns. In step S2, each time the topping treatment is performed, the new branches that have grown to 4-10cm are the targets for topping. The branches are cut horizontally 2-6 buds away from the base of the new branches to remove the top of the new branches.

[0011] Compared with existing technologies, the advantages of this invention are: (1) This invention pre-treats plant stem segments and induces root growth under strong light, which helps to improve the photosynthetic efficiency of the stem segments, enabling them to accumulate nutrients quickly, providing sufficient energy for root growth, shortening the root growth time, and laying the foundation for subsequent weak light acclimatization.

[0012] (2) In the later stages, the new shoots that have taken root are subjected to low light acclimatization, which can not only significantly reduce the transpiration of the stem segments and reduce water loss, but also prevent wilting due to water loss from affecting survival and help the new tender stems remain tender. During the low light acclimatization process, topping is combined to remove apical dominance, inhibit the upward growth of the plant, promote the germination of lateral buds and the formation of branches, reduce the nutrient consumption of the mature tissue at the top, and allow more nutrients to be supplied to the tender parts, further strengthening the juvenile growth of the plant. Attached Figure Description

[0013] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0014] Figure 1 This is an experimental diagram of stem segment pretreatment and root induction provided by the present invention, wherein... Figure 1 Figure A shows stem cuttings; Figure B shows the induction of buds from stem cuttings; Figure C shows the transplanting of stem cuttings after budding. Figure 2 This is an experimental diagram of low-light environment acclimatization provided by the present invention, wherein... Figure 2 A shows the topping treatment; 2B shows the plant morphology after multiple toppings; 2C shows a display image without upright areoles. Figure 3 The above are plants that have recovered from juvenile stage after being acclimatized to low light, as provided in Embodiment 1 of the present invention. 3A represents the morphology of the plant after the second topping; 3B represents the plant that has recovered from juvenile stage. Figure 4 The plantlets that have recovered from juvenile stage after being subjected to low light acclimatization, as provided in Embodiment 2 of the present invention; Figure 5 The diagram showing the relationship between the number of times the needle was struck and the shape of the sarcophagus provided by this invention, wherein... Figure 5 A shows the areole morphology of the plant before topping; 5B shows the areole morphology of the plant after the first topping; 5C shows the areole morphology of the plant after the second topping; 5D shows the areole morphology of the plant after the third topping. Figure 6These are experimental diagrams illustrating the induction culture of explants provided by this invention, where 6A shows the bacterial contamination status; 6B shows the browning status; and 6C shows the failure of induced differentiation. Figure 1 6D indicates failed induced differentiation. Figure 2 ; Figure 7 This is a comparison diagram of the induction of explants in Comparative Example 1 and Example 1 provided by the present invention. Detailed Implementation

[0015] In this invention, unless otherwise specified, the raw materials, equipment and methods used are all conventional selections.

[0016] The plant juvenile stage described in this invention refers to the growth and development stage from seed germination until the plant acquires reproductive capacity (the ability to form flower buds), during which flowering cannot be induced. During this period, even with the most suitable photoperiod, temperature, and other flowering induction conditions, the plant will not flower. Essentially, it is the plant's internal "immature period," a time of physiological and morphological preparation for reproduction.

[0017] The JTB32 described in this invention is a multi-generational seedling offspring of the dragon fruit (F3 generation), that is, a phenotypic segregated seedling propagated from dragon fruit seeds. It is available for purchase by the public.

[0018] To further illustrate the present invention, the solutions provided by the present invention will be described in detail below with reference to the accompanying drawings and embodiments, but these should not be construed as limiting the scope of protection of the present invention.

[0019] Example 1 The dragon fruit variety used in the experiment was JTB32. The specific experimental steps are as follows: I. Stem segment pretreatment and root induction; some experimental procedures are detailed below. Figure 1 (exist Figure 1 In the image (A shows stem cuttings; B shows the induction of buds from stem cuttings; C shows the transplanting of stem cuttings after budding),... 1. Stem segment selection: Cut mature dragon fruit branches to 5-10 cm, ensuring that each branch has 3 buds and exposes the central column to obtain dragon fruit stem segments; cut the base of the stem segment obliquely to increase the water absorption area, and cut the top flat to reduce water evaporation, to obtain stem segments to be disinfected; 2. Drying and disinfection: Place the wounds of the stem segments to be disinfected in a cool and ventilated place to air dry naturally. After 48-72 hours, the cuts will be completely healed, resulting in dried stem segments. Soak the base of the dried stem segments in a 1000-fold dilution of 50% carbendazim wettable powder for 5 minutes, then remove and air dry the surface moisture again to obtain disinfected stem segments (i.e., pre-treated stem segments). 3. Rooting Induction by Cuttings: Introduce the disinfected stem segments into the dragon fruit mixed substrate for rooting induction. (The depth of the stem segments should be 3-5cm. During rooting induction, the light intensity (strong light) should be 8000 lux, the daily light duration should be 12 hours, the temperature should be 26℃ when there is light and 24℃ when there is no light, and the air humidity should be maintained at 80%). The mixed substrate is prepared by mixing peat moss, vermiculite, and perlite in a volume ratio of 2:1:1. After mixing, the substrate is sprayed with 50% carbendazim powder (diluted 1000 times) for disinfection. The moisture level of the mixed substrate is such that it can be formed into a ball when squeezed in the hand, but crumbles when released. During the rooting period, the moisture level of the mixed substrate should be maintained by replenishing water.

[0020] 4. Sprouting: About 25-35 days after cutting, the stem segments will begin to sprout new buds. When the new buds grow to 1-2 cm, they will be transplanted to obtain stem segments that will be acclimatized to low light (these stem segments will have completed rooting and grown new buds of 1-2 cm).

[0021] II. Low-light environment acclimatization: The low-light environment acclimatization process involved topping treatment; some experimental procedures can be found in [link to experimental procedures]. Figure 2 (exist Figure 2 In the diagram, A represents topping treatment; B shows the plant's morphology after multiple topping treatments; and C shows a plant without erect areoles.

[0022] 1. Transplanting and Low-Light Cultivation: Transfer the stem segments to new cultivation pots (containing a mixed substrate, which is a mixture of peat moss, vermiculite, and perlite in a volume ratio of 2:1:1; after mixing, the substrate is disinfected by spraying with 50% carbendazim powder (diluted 1000 times)) for individual cultivation (i.e., low-light acclimatization cultivation). During individual cultivation, the environmental parameters are: light intensity 2000 lux, daily light duration 16 h (temperature 30℃ during light cultivation), and dark cultivation for 8 h (temperature 20℃); air circulation: slight ventilation, wind speed 0.2-0.4 m / s; air humidity 85%. After 15-30 days of individual cultivation, new shoots will develop into weak seedlings 5-10 cm long.

[0023] 2. Pinching: Pinching is performed on the weak seedlings that are 5-10 cm long. This involves cutting off the top of the seedling 5-6 buds from the base (the scissors used for pinching should be disinfected with 75% alcohol beforehand to prevent infection). This results in the first pinched seedling. The seedlings after the first pinching are then cultured individually in a low-light environment (environmental parameters: light intensity 2000 lux, 16 hours of light per day (temperature 30℃ during light cultivation), 8 hours of dark cultivation (temperature 20℃); air circulation: slight ventilation, wind speed 0.2-0.4 m / s; air humidity 85%). After approximately 15-30 days, secondary buds will sprout from the top of the seedlings after the first pinching (the secondary buds will be 5-10 cm long). Cut off the top of the secondary shoot 5-6 buds away from the base of the secondary shoot (cm) for a second topping. After topping 5 times in the above manner, the areoles of the new branches will be velvety and will not contain any upright thorns, thus obtaining a plant that has recovered to its juvenile stage.

[0024] Example 2 The dragon fruit variety used in the experiment was: Thornless Red. The specific experimental steps are as follows: I. Stem segment pretreatment and root induction: 1. Stem segment selection: Select mature, thornless red seedlings with plump internodes and no mechanical damage. Cut the seedlings into stem segments of 4-8 cm in length, ensuring that each segment contains 3-4 intact buds and exposes the central column to promote callus formation. Make a slanted cut at the base of the stem segment to obtain the stem segment to be disinfected.

[0025] 2. Drying and disinfection: The steps of drying and disinfection are the same as in Example 1, to obtain disinfected stem segments (i.e., pre-treated stem segments). 3. Rooting Induction by Cuttings: Introduce the disinfected stem segments into the dragon fruit mixed substrate for rooting induction. During this process, the base needs to be compacted (the depth of the stem segment insertion is 4-6 cm; during rooting induction, the light intensity (strong light) is 6000-7000 lux, the daily light duration is 14 hours, the temperature is 26℃ when there is light and 24℃ when there is no light, and the air humidity is maintained at 80%). The mixed substrate is obtained by mixing peat, vermiculite, and perlite in a volume ratio of 3:1:1. After mixing, the substrate is sprayed with 50% carbendazim powder (diluted 1000 times) for disinfection. The moisture level of the mixed substrate is such that it can be formed into a ball when squeezed in the hand, but crumbles when released. During the rooting period, the moisture level of the mixed substrate is maintained by replenishing water.

[0026] 5. Sprouting: After about 15-20 days, the induced rooted stem segments will begin to sprout new buds. When the new buds grow to about 1 cm-2 cm, they will be transplanted to obtain stem segments ready for low light acclimatization.

[0027] II. Acclimatization to Low-Light Environments 1. Transplanting and Low-Light Acclimation: Transplant the stem segments to be acclimated to low light into new culture pots (10 cm × 10 cm, containing a mixed substrate, which is a mixture of peat, vermiculite, and perlite in a volume ratio of 2:1:1, and disinfected by spraying with 50% carbendazim powder (diluted 1000 times)) for individual cultivation (i.e., low-light acclimation cultivation). During individual cultivation, the environmental parameters are: light intensity 1500 lux, daily light duration 14 h (at a temperature of 28℃), dark cultivation for 10 h (at a temperature of 22℃), air circulation: slight ventilation, wind speed 0.2-0.4 m / s; air humidity 85%. After 10-12 days of individual cultivation, the stem segments will develop into weak seedlings 6-8 cm long.

[0028] 2. Topping: For the weak seedlings that are 6-8 cm long, perform the first topping treatment, retaining 5 buds from the base upwards, and cut off the top horizontally (the scissors used for topping should be disinfected with 75% alcohol beforehand to avoid wound infection). This results in the weak seedlings after the first topping. These seedlings are then cultured individually in a low-light environment (environmental parameters: light intensity 1800 lux, 14 hours of light per day (temperature 28℃), 10 hours of dark culture (temperature 22℃), air circulation: slight ventilation, wind speed 0.2-0.4 m / s; air humidity 85%). After 10-15 days of cultivation, secondary buds will grow from the top of the seedlings after the first topping. When these secondary buds reach 5-6 cm in length, retain 4 buds from the base upwards and perform a second topping treatment by cutting off the top horizontally. This results in the weak seedlings after the second topping treatment. After the second topping treatment, the environmental parameters are: light intensity 1500 lux. Lux, 14 hours of light per day (at 28℃), 10 hours of dark culture (at 22℃), air circulation: slight ventilation, wind speed 0.2-0.4 m / s; air humidity 85%, inducing the gradual weakening of weak seedlings after the second topping, when the areoles of new branches show velvety protrusions until there are no upright hard thorns, resulting in plants that have recovered to juvenile stage (e.g. Figure 3 As shown, in Figure 3 In the image, A represents the morphology of the plant after the second topping; B represents the plant after it has recovered to its juvenile stage.

[0029] Example 3 The dragon fruit variety used in the experiment was: Jindu. The specific experimental steps are as follows: I. Stem segment pretreatment and root induction: The process is exactly the same as the stem segment pretreatment and root induction process in Example 2.

[0030] II. Acclimatization to Low-Light Environments The only difference from Example 2 is that Example 3 involved three topping treatments to obtain plants that had recovered to juvenile stage. The areoles of these plants were densely covered with downy hairs, lacking any erect thorns. The stem nodes turned yellowish-green, and the internode length was 3.5-4.2 cm. The shape of the recovered juvenile plant was as follows: Figure 4 The number of times the areoles were struck and the changes in the shape of the areoles are shown in the figure. Figure 5 (exist Figure 5 In the diagram, A represents the areole morphology of the plant before topping; B represents the areole morphology of the plant after the first topping; C represents the areole morphology of the plant after the second topping; and D represents the areole morphology of the plant after the third topping.

[0031] Comparative Example 1 The dragon fruit variety used in the experiment was JTB32. Select new shoots 5-10cm long from dragon fruit branches grown under natural conditions as explants.

[0032] Comparative Example 2 The only difference from Example 1 is that when Comparative Example 2 was subjected to low-light environment acclimatization, the light intensity was 800 lux.

[0033] Comparative Example 3 The only difference from Example 1 is that when Comparative Example 3 was subjected to low-light environment acclimatization, the light intensity was 3500 lux.

[0034] Comparative Example 4 The only difference from Example 1 is that the topping process in Example 4 is as follows: 2. Topping: Perform the first topping treatment on the weak seedlings that are 5-10 cm tall. Keep 5 buds from the base upwards and cut off the top horizontally (the scissors used for topping should be disinfected with 75% alcohol beforehand to avoid wound infection). The weak seedlings after the first topping will grow new branches with areoles that are velvety protrusions but have upright hard thorns, resulting in plants that have initially recovered from their juvenile stage.

[0035] Verification Example 1 Plants (5-10 cm) that had recovered to juvenile stage obtained in Examples 1-3 were selected as explants to be verified (labeled as explants of Example 1, Example 2, and Example 3, respectively). Explants from Comparative Example 1 (labeled as explants of Comparative Example 1) and plants (5-10 cm) acclimatized to low-light environments from Comparative Examples 2-4 were also selected as explants to be verified (labeled as explants of Comparative Example 2, Comparative Example 3, and Comparative Example 4, respectively) for the following operations: The explants (each with areoles) were disinfected as follows: the explants were placed in a container and rinsed with running water for 15 minutes (the small spines and soft hairs on the areoles were retained during rinsing); the rinsed explants were transferred to a clean bench, rinsed once with sterile water, and then soaked in 75% alcohol for 10 seconds; then placed in a 3% sodium hypochlorite solution (the 3% sodium hypochlorite solution is a sterile aqueous solution with an effective chlorine mass-volume fraction of 3%, used for plant surface disinfection) for disinfection with continuous stirring to ensure thorough disinfection; after disinfection, the explants were rinsed 5 times with sterile water for 3 minutes each time to obtain the disinfected explants.

[0036] Induction of adventitious shoots: The above-sterilized explants were cut into small segments (specifically: the dried parts at both ends of the explant stem segments were cut off, and the sterilized explants were cut into small segments of 1-3 cm in length with 2-3 areoles), and then inoculated into adventitious shoot induction medium for induction culture (30 samples of each type of explant, each sample was inoculated into 1 culture bottle for induction culture). The induction medium was MS medium containing 3.5 mg / L 6-BA, 0.15 mg / L NAA, 35 g / L sucrose, and 7 g / L agar. The induction conditions were: temperature 25 ± 2℃, light intensity 12-14 h / d, and light intensity 5000 Lux. Observations and statistics were performed during the 30-45 days of induction culture. Specifically: the number of explants contaminated with bacteria was counted on day 7 of culture; the number of explants showing browning was counted on day 21 of culture; and the number of explants differentiating (i.e., the number of successfully induced adventitious shoots) was counted on day 42 of culture. The results are shown in Table 1. The experimental diagram of the induction culture using explants from Comparative Example 1 is shown below. Figure 6 (exist Figure 6 In the diagram, A shows the bacterial contamination status; B shows the browning status; and C shows the failure of induced differentiation. Figure 1 D indicates failed induced differentiation. Figure 2 (See the comparison diagram of explant induction in Example 1 and Example 1). Figure 7 (exist Figure 7 In the middle, the left figure shows the induction of explants in Comparative Example 1; the right figure shows the induction of explants in Example 1.

[0037] After explants were inoculated into the culture medium and cultured for 42 days, the adventitious shoot proliferation coefficient (i.e., the number of robust new adventitious shoots of 3-5 cm / the number of inoculated explants) for each treatment was calculated. The results are shown in Table 2.

[0038] Table 1 Effects of different treatments on induction culture

[0039] As can be seen from the data in Table 1, when using mature dragon fruit branches as explants for adventitious bud induction in Comparative Example 1, the plants were prone to fungal infection and browning during the culture process. After induction culture, the two explants in Comparative Example 1 that did not turn brown failed to differentiate. Similarly, in Comparative Examples 2-4, modifying the low-light acclimatization conditions or the topping treatment also resulted in easy fungal infection and browning during the culture process, both of which were detrimental to the successful induction of explant differentiation. In contrast, when plants that had recovered to juvenile stage were cultured using the methods described in Examples 1-3, the induction rate using these plants as explants for induction culture was as high as 90% or more.

[0040] Table 2. Proliferation coefficients of adventitious buds under different treatments

[0041] As can be seen from the data in Table 2, since the explants in the comparative examples were all undergoing differentiation, there was no proliferation coefficient available for statistical analysis. However, after adopting the technical solutions in Examples 1-3, the proliferation coefficient of dragon fruit adventitious buds was as high as 6.67-9.5. This indicates that after obtaining plants that have recovered from juvenile stage using the technical solution of this invention, using these plants as explants for tissue culture is more conducive to their differentiation and culture.

[0042] Verification Example 2 Following the method described in Verification Example 1, adventitious buds were induced and cultured using the rejuvenated plants obtained in Examples 1-3 as explants, resulting in adventitious buds for Examples 1, 2, and 3, respectively. These adventitious buds were then subcultured (the culture medium used for subculture was: MS + 6-BA 3.5 mg / L + NAA 0.15 mg / L + sucrose 35 g / L + agar 7 g / L; the induction culture conditions were: temperature 25 ± 2℃, light 12-14 h / d, light intensity 5000 Lux, culture for 30-40 days), yielding subcultured adventitious buds (corresponding to the subcultured adventitious buds of Examples 1, 2, and 3, respectively).

[0043] Subcultured adventitious shoots of 2-3 cm in length were selected and transferred to rooting medium for rooting culture. For rooting culture, 30 samples of each subcultured adventitious shoot were prepared, with each sample inoculated into one culture flask. The rooting medium consisted of 1 / 2 MS medium + IBA 0.8 mg / L + NAA 0.1 mg / L + activated charcoal 0.5 g / L + agar 7 g / L. The rooting conditions were: temperature 25±2℃, light intensity 12-14 h / d, and light intensity 5000 Lux. After 30 days of culture, the rooting rate of each treatment was calculated, and the results are shown in Table 3.

[0044] Table 3. Rooting rate of adventitious buds under different treatments

[0045] As can be seen from the data in Table 3, the rooting rate of adventitious buds from dragon fruit subcultures reached 90%-93% after adopting the technical solution of this invention. Therefore, the technical solution of this application is beneficial for improving the survival rate of explants and increasing tissue culture efficiency.

[0046] Although the above embodiments have provided a detailed description of the present invention, they are only some embodiments of the present invention, and not all embodiments. People can obtain other embodiments based on these embodiments without creative effort, and these embodiments all fall within the protection scope of the present invention.

Claims

1. A method for inducing plants to revert to juvenile stage, characterized in that, Includes the following steps: S1. Pre-treat the plant stem segments, then induce root growth under strong light to obtain new shoots; S2. The new shoots are subjected to low light acclimatization to obtain plants in their juvenile stage; The process of acclimatizing to low light is accompanied by a topping treatment. The plant is dragon fruit; the varieties of dragon fruit include one or more of JTB32, Thornless Red, and Golden Dragon. In step S2, when the new shoots grow to 1-2cm, they undergo low-light acclimatization. The light intensity for low-light acclimatization is 1500-3000 lux, the light duration is 14-16h / d, and the air humidity is 70%-85%. The temperature during light exposure is 25-30℃, and the temperature during darkness is 20-24℃. In step S2, the low-light acclimatization ends when the areoles of the branches are velvety and do not contain erect thorns. In step S2, each time the topping treatment is performed, the new branches that have grown to 4-10cm are the targets for topping. The branches are cut flat 2-6 buds away from the base of the new branches to remove the top of the new branches. In step S1, the intensity of the strong light is 6000-8000 Lux; during the induction of rooting, the air humidity is 80%-90% and the light duration is 12-16 h / d; the temperature during the light is 26-28℃ and the temperature during the darkness is 20-24℃.

2. The method according to claim 1, characterized in that, In step S1, the pretreatment method includes: air-drying the wounds of the stem segment, immersing and disinfecting the base of the stem segment, and then air-drying it to obtain the pretreated stem segment; The stem segment is 4-10cm in length and contains 3-4 complete buds; The base of the stem segment is the base after oblique cutting.

3. The application of the method according to claim 1 or 2 in improving the efficiency of dragon fruit tissue culture and / or preparing sterile dragon fruit seedlings.

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