A method for promoting rooting of plant cuttings using graphene oxide

Abstract

This invention discloses a method for promoting rooting of plant cuttings using graphene oxide, belonging to the field of plant cultivation technology. The method involves immersing the base of the cuttings to be rooted in a graphene oxide solution, then transferring them to a rooting solution containing graphene oxide. After drying for 5-10 minutes, the treated cuttings are directly inserted into the substrate. This invention utilizes graphene oxide to promote the absorption of plant growth regulators by the cuttings, while reducing the influence of endogenous rooting inhibitors on root formation. Using this method, the rooting rate is increased by approximately 10-40%, and the growth is significantly improved, resulting in a well-developed and robust root system. This invention not only promotes plant rooting and root growth and development, increasing the growth of cuttings, but also reduces bacterial infection and improves survival rate. Furthermore, it is low-cost, simple to prepare, easy to use, and highly effective.

Description

Technical Field

[0001] This invention relates to the field of plant cultivation technology, and in particular to a method for promoting rooting of plant cuttings using graphene oxide. Background Technology

[0002] Graphene oxide (GO) is a type of special graphene family nanomaterial (GFNs) that has undergone surface functionalization modification. Its monolayer of carbon atoms contains π-π stacking forces on its basal planes and is connected with abundant functional groups, including hydroxyl, carboxyl, and epoxy bonds, making it an oxide form of graphene. It possesses a high specific surface area and abundant functional groups: hydroxyl and epoxy groups on the basal surface and carboxyl groups at the edges. These functional groups endow GO with excellent hydrophilicity, dispersibility, and biocompatibility. The abundant hydrophilic functional groups on the surface of GO allow it to remain stable when dispersed in water. Well-modified GO can remain stable in both high-salt solutions and physiological conditions, laying the foundation for its applications in biology. Studies have found that graphene materials exhibit strong adsorption properties for organic pollutants, heavy metal ions, macromolecules (DNA, proteins, humic acid), and other nanoparticles.

[0003] Stem cuttings are one of the most widely used methods for propagating woody plants. The survival rate and growth of cuttings depend crucially on their rooting ability; the number of roots produced by the cutting determines the success or failure of propagation. Plant growth regulators are widely used in stem cutting propagation to stimulate the formation of adventitious roots in the cuttings.

[0004] However, plant growth regulators require full absorption by the epidermal cells and cross-sectional cortical cells of the cuttings to achieve significant effects. Some difficult-to-root tree species have dense epidermal cells, resulting in poor absorption capacity. Some cuttings also have severely lignified cork cell walls, hindering the full absorption of plant growth regulators. Furthermore, some varieties contain large amounts of polyphenols, tannins, flavonoids, and other root-inhibiting substances in their cuttings, impeding root formation. For example, the white poplar is a difficult-to-root species, and its dense epidermal cells make it difficult to fully absorb plant growth regulators. The American smoke tree is a colorful-leaved species, and its cuttings contain large amounts of polyphenols and tannins, root-inhibiting substances; both species exhibit low rooting rates from cuttings. Currently, the application of graphene oxide is mostly through direct spraying onto plants or into the substrate (soil) to enhance plant growth or nitrogen fixation capacity. However, there are no literature reports on its application in plant cuttings to reduce root-inhibiting substances and promote the absorption of plant growth regulators. Summary of the Invention

[0005] The purpose of this invention is to provide a method for promoting rooting of plant cuttings using graphene oxide. Graphene oxide promotes the absorption of plant growth regulators by the cuttings, while reducing the influence of endogenous rooting inhibitors on root formation, thereby improving the rooting rate of cuttings and solving the above-mentioned problems existing in the prior art.

[0006] To achieve the above objectives, the present invention provides the following solution:

[0007] One of the technical solutions of the present invention is a method for promoting rooting of plant cuttings using graphene oxide, characterized in that the base of the cutting to be rooted is immersed in a graphene oxide solution for treatment, and then transferred to a rooting solution containing graphene oxide for treatment. After the treated cuttings are dried for 5 to 10 minutes, they are directly inserted into the substrate.

[0008] Furthermore, the concentration of graphene oxide in the graphene oxide solution is the same as the concentration of graphene oxide in the rooting solution containing graphene oxide.

[0009] Furthermore, the rooting solution containing graphene oxide has one of the following two components: (1) a mixture of 200-500 mg / L LABT1 rooting powder + 1 g / L mineral potassium humate + 25-50 mg / L graphene oxide; (2) a mixture of rooting powder diluted 100-500 times + 25-50 mg / L graphene oxide.

[0010] Treatment with graphene oxide solution can reduce the impact of endogenous rooting inhibitors on root formation, and has a good effect on colorful-leaved woody plants. In addition, graphene oxide can stimulate the absorption of rooting powder by epidermal cells and cork cells, promote plant rooting and root growth and development, and increase the growth of cuttings. Graphene oxide also has a bactericidal effect, which can reduce bacterial infection and improve the survival rate.

[0011] ABT Rooting Powder is a novel, broad-spectrum, and highly effective plant growth regulator. It breaks through the traditional method of simply providing exogenous hormones needed for plant growth and development. By strengthening and regulating the content of endogenous plant hormones and the activity of important enzymes, it promotes the synthesis of biomolecules, induces the morphogenesis of adventitious roots, and regulates the intensity of plant metabolism, thereby improving seedling survival rates, crop yield, quality, and resistance. Rooting Powder is a compound of indolebutyric acid (IBA) and naphthaleneacetic acid (NAA). IBA induces a large number of adventitious roots, while NAA induces robust taproots, but fewer roots. The combined use of both promotes rapid root growth, resulting in numerous, strong roots, a well-developed root system, improved nutrient absorption, and more vigorous growth.

[0012] Furthermore, the soaking time in the graphene oxide solution is 4-8 minutes, and the soaking time in the rooting solution containing graphene oxide is 10-20 minutes.

[0013] Furthermore, the graphene oxide solution contains graphene oxide with an average thickness of 2–4 nm, a sheet diameter of 40–60 nm, 4–6 layers, and a purity >90%.

[0014] The graphene oxide in the rooting solution containing graphene oxide has the same properties as the graphene oxide in the graphene oxide solution.

[0015] Furthermore, the plant is either white poplar or American smoke tree.

[0016] Furthermore, the cuttings are either softwood cuttings or hardwood cuttings.

[0017] Furthermore, when the plant is white poplar, softwood cuttings or hardwood cuttings are selected; when the plant is smoke tree, softwood cuttings are selected.

[0018] Furthermore, when the cutting is softwood cutting, select healthy, well-developed branches that are free from pests and diseases, and cut branches with a length of 14-16cm as cuttings to be rooted; when the cutting is hardwood cutting, select semi-lignified branches of the plant that are in the current year, and cut branches with a length of 14-16cm, a uniform diameter, and two leaves as cuttings to be rooted.

[0019] Furthermore, for hardwood cuttings, the selection (collection) of cuttings should be carried out in spring, preferably early, before the leaf buds sprout. Cuttings should be planted immediately after collection, and there is no need to store them in trenches. For softwood cuttings, the selection (collection) of cuttings should be carried out in early June, and cuttings should be planted immediately after collection. Cuttings do not need to be stored in trenches. When taking cuttings, if the leaves are too large, they can be cut off in half.

[0020] Furthermore, the substrate is composed of one or more of peat moss, perlite, vermiculite, and river sand, and is disinfected with potassium permanganate solution before cutting.

[0021] Furthermore, the specific operations for post-cutting management are as follows: water thoroughly immediately after cutting; greenhouse management requirements are a temperature of 20-28℃ and a relative humidity of 60-90%; disinfect every 3 days; gradually ventilate, reduce humidity and increase light after 15 days of cutting.

[0022] Furthermore, as ventilation progresses, the humidity gradually decreases until it reaches the outdoor natural humidity level.

[0023] Furthermore, disinfection is carried out every 3 days, specifically using an 800-fold dilution of carbendazim solution.

[0024] Furthermore, the specific operation for disinfecting the substrate is as follows: spray a 0.5-1.0 wt.% potassium permanganate solution onto the solid substrate, mix it evenly with the substrate, then wrap the substrate with plastic sheeting for 20-30 minutes, and then rinse it clean with water.

[0025] Furthermore, when propagating softwood cuttings, the relative humidity should be controlled at 70-90% after the cuttings are taken, and when propagating hardwood cuttings, the relative humidity should be controlled at 60-80% after the cuttings are taken.

[0026] Furthermore, seedling trays and nutrient pots are used for propagation, and the cuttings are planted immediately after treatment. The planting depth should be such that the base of the bud on the cutting is just above the ground, and the cuttings should be planted vertically.

[0027] The present invention discloses the following technical effects:

[0028] This invention utilizes graphene oxide to promote the absorption of plant growth regulators in rooting solution by cuttings, while simultaneously reducing the impact of endogenous rooting inhibitors on root formation. Using this method, the rooting rate is increased by approximately 10-40%, and the growth is significantly enhanced, resulting in well-developed and robust root systems. This invention not only promotes plant rooting and root growth and development, increasing the growth of cuttings, but also reduces bacterial infection and improves survival rate. Furthermore, it is low-cost, simple to manufacture, convenient to use, and highly effective. Detailed Implementation

[0029] Various exemplary embodiments of the present invention will now be described in detail. This detailed description should not be considered as a limitation of the present invention, but rather as a more detailed description of certain aspects, features, and embodiments of the present invention.

[0030] It should be understood that the terminology used in this invention is merely for describing particular embodiments and is not intended to limit the invention. Furthermore, with respect to numerical ranges in this invention, it should be understood that each intermediate value between the upper and lower limits of the range is also specifically disclosed. Every smaller range between any stated value or intermediate value within a stated range, and any other stated value or intermediate value within said range, is also included in this invention. The upper and lower limits of these smaller ranges may be independently included or excluded from the range.

[0031] Unless otherwise stated, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. While only preferred methods and materials have been described herein, any methods and materials similar or equivalent to those described herein may be used in the implementation or testing of this invention. All references to this specification are incorporated by way of citation to disclose and describe methods and / or materials associated with those references. In the event of any conflict with any incorporated reference, the content of this specification shall prevail.

[0032] Various modifications and variations can be made to the specific embodiments described in this specification without departing from the scope or spirit of the invention, as will be apparent to those skilled in the art. Other embodiments derived from this specification will also be obvious to those skilled in the art. This application specification and embodiments are merely exemplary.

[0033] The terms “include,” “including,” “have,” “contain,” etc., used in this article are all open-ended terms, meaning that they include but are not limited to.

[0034] The graphene oxide used in the following examples and comparative examples is from the School of Chemical Engineering / Institute of Carbon Materials, Datong University, Shanxi Province. Its average thickness is 2-4 nm; the sheet diameter is 40-60 nm; the number of layers is about 5; it can form a stable dispersion in water; and its purity is 95%.

[0035] The root-protecting agent (Guoguang root-protecting indole·naphthaleneacetic acid) used in the following examples and comparative examples was purchased from Sichuan Guoguang Agrochemical Co., Ltd., pesticide registration certificate number: PD20110559; pesticide production approval document number: HNP51053-E0770; product approval number: Q / 20686114-8·65-2016; it is a yellowish-brown soluble agent.

[0036] The ABT1 rooting powder used in the following examples and comparative examples was purchased from Beijing Aibiti Biotechnology Co., Ltd., pesticide registration certificate number: PD20081125; product standard number: Q / CPABT0001-2012; it is a white powder.

[0037] The potassium humate used in the following examples and comparative examples was purchased from Shanghai Hulian Biopharmaceutical (Xiayi) Co., Ltd., and is a black powder with a potassium humate content of ≥99.9%.

[0038] The cutting containers used in the following examples and comparative examples are seedling trays and nutrient pots.

[0039] Example 1

[0040] The hardwood cuttings of Populus tomentosa include the following steps:

[0041] (1) Cuttings collection: Cuttings are taken in a greenhouse in mid-April. The cuttings are taken from the one-year-old shoots of mature and superior Populus tomentosa trees. The branches with a length of 15cm and a uniform diameter are cut as cuttings to be rooted.

[0042] (2) Substrate treatment: River sand is selected as the cutting substrate. Potassium permanganate solution is used for disinfection. The specific operation is as follows: spray 1.0 wt.% potassium permanganate solution on the solid substrate and mix it evenly with the substrate. Then wrap the substrate with plastic sheeting for 30 minutes, rinse it with clean water, and let it dry for 2 days before use.

[0043] (3) Cutting treatment and propagation: Prepare solution A: graphene oxide solutions with concentrations of 25, 50, 75 and 100 mg / L respectively; solution B (rooting solution containing graphene oxide): 300 mg / L ABT1 rooting powder + 1 g / L mineral potassium humate + 25 / 50 / 75 / 100 mg / L graphene oxide mixture (four solutions with different graphene oxide concentrations); the graphene oxide concentrations in solutions A and B are the same, and each solution is placed in a plastic basin for later use, with purified water used as a control group. Soak the base of the rooting cuttings in solution A for 5 minutes, then transfer them to solution B with the same graphene oxide concentration as solution A for 15 minutes. After drying the treated cuttings for 5 minutes, insert them into the substrate. Before inserting the cuttings, make holes in the prepared substrate with bamboo chopsticks or a metal rod, and then insert the cuttings into the substrate. The insertion depth should be such that the base of the bud on the cutting is just above the ground. Insert the cuttings vertically.

[0044] (4) Post-cutting management: Water thoroughly immediately after cutting to ensure close contact between the cutting and the substrate. Greenhouse management requirements after cutting: Temperature in the greenhouse should be 20-28℃, relative humidity 60-80%, and light and temperature should be controlled with shade netting. Disinfect with an 800-fold dilution of carbendazim solution every 3 days; gradually ventilate, reduce humidity, and increase light after 15 days of cutting.

[0045] (5) After 70 days, the rooting rate and growth were investigated. Each group had 50 cuttings, and the average value was taken.

[0046] The survey results are shown in Table 1:

[0047] Table 1. Effects of different concentrations of graphene oxide on rooting of Populus tomentosa hardwood cuttings (70 days)

[0048]

[0049] Note: A graphene oxide concentration of 0 means that solution A is replaced with pure water, and solution B does not contain graphene oxide. The following examples are the same as this example.

[0050] Example 2

[0051] Same as Example 1, except that the solution B used in step (3) for cutting treatment is different from that in Example 1. Solution B (rooting solution containing graphene oxide) in this example is a mixture of 200 times diluted root extract + 25 / 50 / 75 / 100 mg / L graphene oxide (four solutions with different graphene oxide concentrations).

[0052] The survey results of this embodiment are shown in Table 2:

[0053] Table 2. Effects of different concentrations of graphene oxide on rooting of Populus tomentosa hardwood cuttings (70 days)

[0054]

[0055] Example 3

[0056] Populus tomentosa softwood cuttings include the following steps:

[0057] (1) Cuttings collection: Cuttings are taken in a greenhouse in early June. The cuttings are taken from the current year's semi-lignified branches of Populus tomentosa. Cuttings with a length of 15cm and a diameter of the same size with two leaves are used as cuttings to be rooted. If the leaves are too large, half of them can be cut off.

[0058] (2) Substrate treatment: The cutting substrate is a mixture of river sand, peat moss and perlite in a ratio of 7:2:1. It is disinfected with potassium permanganate solution. The specific operation is as follows: spray the solid substrate with 1.0 wt.% potassium permanganate solution and mix it evenly with the substrate. Then wrap the substrate with plastic sheeting for 30 minutes, rinse it with clean water, and let it dry for 2 days before use.

[0059] (3) Cutting treatment and propagation: Prepare solution A: graphene oxide solutions with concentrations of 25, 50, 75 and 100 mg / L respectively; solution B (rooting solution containing graphene oxide): 200 mg / L ABT1 rooting powder + 1 g / L mineral potassium humate + 25 / 50 / 75 / 100 mg / L graphene oxide mixture (four solutions with different graphene oxide concentrations); the graphene oxide concentrations in solutions A and B are the same, and each solution is placed in a plastic basin for later use, with purified water used as a control group. Soak the base of the rooting cuttings in solution A for 5 minutes, then transfer them to solution B with the same graphene oxide concentration as solution A for 10 minutes. After drying the treated cuttings for 5 minutes, insert them into the substrate. Before inserting the cuttings, make holes in the prepared substrate with bamboo chopsticks or a metal rod, and then insert the cuttings into the substrate. The insertion depth should be such that the base of the bud on the cutting is just above the ground. Insert the cuttings vertically.

[0060] (4) Post-cutting management: Water thoroughly immediately after cutting to ensure close contact between the cutting and the substrate. Greenhouse management requirements after cutting: Temperature in the greenhouse should be 20-28℃, relative humidity 70-90%, and light and temperature should be controlled with shade netting. Disinfect with an 800-fold dilution of carbendazim solution every 3 days; gradually ventilate, reduce humidity, and increase light after 15 days of cutting.

[0061] (5) After 35 days, the rooting rate and growth were investigated. Each group had 50 cuttings, and the average value was taken.

[0062] The survey results are shown in Table 3:

[0063] Table 3. Effects of different concentrations of graphene oxide on rooting of Populus tomentosa cuttings (35 days)

[0064]

[0065] Example 4

[0066] Same as Example 3, except that the solution B used in step (3) for treating the cuttings is different from that in Example 3. Solution B (rooting solution containing graphene oxide) in this example is a mixture of 500 times diluted root extract + 25 / 50 / 75 / 100 mg / L graphene oxide (four solutions with different graphene oxide concentrations).

[0067] The survey results of this embodiment are shown in Table 4:

[0068] Table 4. Effects of different concentrations of graphene oxide on rooting of Populus tomentosa cuttings (35 days)

[0069]

[0070] Example 5

[0071] Propagation of American smoke tree (Cotinus coggygria) by softwood cuttings includes the following steps:

[0072] (1) Cuttings collection: Cuttings are taken in a greenhouse. In early June, or on a cloudy or rainy day, cuttings are collected. The cuttings are taken from the current year's semi-lignified branches of American red smoke tree. Cuttings with a length of 15cm and a diameter of the same size, with two leaves, are used as cuttings to be rooted.

[0073] (2) Substrate treatment: The cutting substrate is a mixture of river sand, peat moss and perlite in a ratio of 7:2:1. It is disinfected with potassium permanganate solution. The specific operation is as follows: spray the solid substrate with 1.0 wt.% potassium permanganate solution and mix it evenly with the substrate. Then wrap the substrate with plastic sheeting for 30 minutes, rinse it with clean water, and let it dry for 2 days before use.

[0074] (3) Cutting treatment and propagation: Prepare solution A: graphene oxide solutions with concentrations of 25, 50, 75 and 100 mg / L respectively; solution B (rooting solution containing graphene oxide): 500 mg / L ABT1 rooting powder + 1 g / L mineral potassium humate + 25 / 50 / 75 / 100 mg / L graphene oxide mixture (four solutions with different graphene oxide concentrations); the graphene oxide concentrations in solutions A and B are the same, and each solution is placed in a plastic basin for later use, with purified water used as a control group. Soak the base of the rooting cuttings in solution A for 5 minutes, then transfer them to solution B with the same graphene oxide concentration as solution A for 10 minutes. After drying the treated cuttings for 5 minutes, insert them into the substrate. Before inserting the cuttings, make holes in the prepared substrate with bamboo chopsticks or a metal rod, and then insert the cuttings into the substrate. The insertion depth should be such that the base of the bud on the cutting is just above the ground. Insert the cuttings vertically.

[0075] (4) Post-cutting management: Water thoroughly immediately after cutting to ensure close contact between the cutting and the substrate. Greenhouse management requirements after cutting: Temperature in the greenhouse should be 20-28℃, relative humidity 70-90%, and light and temperature should be controlled with shade netting. Disinfect with an 800-fold dilution of carbendazim solution every 3 days; gradually ventilate, reduce humidity, and increase light after 15 days of cutting.

[0076] (5) After 35 days, the rooting rate and growth were investigated. Each group had 50 cuttings, and the average value was taken.

[0077] The survey results are shown in Table 5:

[0078] Table 5. Effects of different concentrations of graphene oxide on rooting of *Cotinus coggygria* cuttings (35 days)

[0079]

[0080] Example 6

[0081] Same as Example 5, except that the solution B used in step (3) for cutting treatment is different from that in Example 5. Solution B (rooting solution containing graphene oxide) in this example is a mixture of 100 times diluted root extract + 25 / 50 / 75 / 100 mg / L graphene oxide (four solutions with different graphene oxide concentrations).

[0082] The survey results are shown in Table 6:

[0083] Table 6. Effects of different concentrations of graphene oxide on rooting of *Cotinus coggygria* cuttings (35 days)

[0084]

[0085] Comparative Example 1

[0086] The hardwood cuttings of Populus tomentosa include the following steps:

[0087] (1) Cuttings collection: Cuttings are taken in a greenhouse in mid-April. The cuttings are taken from the one-year-old shoots of mature and superior Populus tomentosa trees. The branches with a length of 15cm and a uniform diameter are cut as cuttings to be rooted.

[0088] (2) Substrate treatment: River sand is selected as the cutting substrate. Potassium permanganate solution is used for disinfection. The specific operation is as follows: spray 1.0 wt.% potassium permanganate solution on the solid substrate and mix it evenly with the substrate. Then wrap the substrate with plastic sheeting for 30 minutes, rinse it with clean water, and let it dry for 2 days before use.

[0089] (3) Cutting treatment and propagation: Prepare solution A: graphene oxide solutions with concentrations of 25, 75, and 100 mg / L; solution B (rooting solution containing graphene oxide): a mixture of 300 mg / L ABT1 rooting powder + 1 g / L mineral potassium humate + 50 mg / L graphene oxide; each solution is placed in a plastic basin for later use. Soak the base of the cuttings to be rooted in solution A for 5 minutes, then transfer them to solution B for 15 minutes. After the treated cuttings have been dried for 5 minutes, they are then propagated. Before propagation, make holes in the prepared substrate with bamboo chopsticks or a metal rod, and then insert the cuttings into the substrate. The propagation depth should be such that the base of the bud on the cutting is just above the ground. The cuttings should be planted vertically.

[0090] (4) Post-cutting management: Water thoroughly immediately after cutting to ensure close contact between the cutting and the substrate. Greenhouse management requirements after cutting: Temperature in the greenhouse should be 20-28℃, relative humidity 60-80%, and light and temperature should be controlled with shade netting. Disinfect with an 800-fold dilution of carbendazim solution every 3 days; gradually ventilate, reduce humidity, and increase light after 15 days of cutting.

[0091] (5) After 70 days, the rooting rate and growth were investigated. A total of 50 cuttings were inserted, and the average value of the results was taken.

[0092] The survey results are shown in Table 7.

[0093] Table 7. Effects of different concentrations of graphene oxide on rooting of Populus tomentosa cuttings (70 days)

[0094]

[0095] Comparative Example 2

[0096] The hardwood cuttings of Populus tomentosa include the following steps:

[0097] (1) Cuttings collection: Cuttings are taken in a greenhouse in mid-April. The cuttings are taken from the one-year-old shoots of mature and superior Populus tomentosa trees. The branches with a length of 15cm and a uniform diameter are cut as cuttings to be rooted.

[0098] (2) Substrate treatment: River sand is selected as the cutting substrate. Potassium permanganate solution is used for disinfection. The specific operation is as follows: spray 1.0 wt.% potassium permanganate solution on the solid substrate and mix it evenly with the substrate. Then wrap the substrate with plastic sheeting for 30 minutes, rinse it with clean water, and let it dry for 2 days before use.

[0099] (3) Cutting treatment and propagation: Prepare solution B (rooting solution containing graphene oxide): a mixture of 300 mg / L ABT1 rooting powder + 1 g / L potassium humate + 50 mg / L graphene oxide, placed in a plastic basin for later use. Immerse the base of the cuttings to be rooted in solution B for 15 minutes. After the treated cuttings have dried for 5 minutes, proceed with propagation. Before propagation, make holes in the prepared substrate with bamboo chopsticks or a metal rod, then insert the cuttings into the substrate. The propagation depth should be such that the base of the bud on the cutting is just above the ground, and the cuttings should be planted vertically.

[0100] (4) Post-cutting management: Water thoroughly immediately after cutting to ensure close contact between the cutting and the substrate. Greenhouse management requirements after cutting: Temperature in the greenhouse should be 20-28℃, relative humidity 60-80%, and light and temperature should be controlled with shade netting. Disinfect with an 800-fold dilution of carbendazim solution every 3 days; gradually ventilate, reduce humidity, and increase light after 15 days of cutting.

[0101] (5) After 70 days, the rooting rate and growth were investigated. A total of 50 cuttings were inserted, and the average value of the results was taken.

[0102] According to statistics, the rooting rate was 62%, the diameter of the new shoots was 0.78±0.1mm, and the height of the new shoots was 31.35±2.2cm.

[0103] Comparative Example 3

[0104] The hardwood cuttings of Populus tomentosa include the following steps:

[0105] (1) Cuttings collection: Cuttings are taken in a greenhouse in mid-April. The cuttings are taken from the one-year-old shoots of mature and superior Populus tomentosa trees. The branches with a length of 15cm and a uniform diameter are cut as cuttings to be rooted.

[0106] (2) Substrate treatment: River sand is selected as the cutting substrate. Potassium permanganate solution is used for disinfection. The specific operation is as follows: spray 1.0 wt.% potassium permanganate solution on the solid substrate and mix it evenly with the substrate. Then wrap the substrate with plastic sheeting for 30 minutes, rinse it with clean water, and let it dry for 2 days before use.

[0107] (3) Cutting treatment and propagation: Prepare solution A: a graphene oxide solution with a concentration of 25 mg / L; solution B (rooting solution containing graphene oxide): a mixture of 300 mg / L ABT1 rooting powder and 25 mg / L graphene oxide; each solution is placed in a plastic basin for later use. Soak the base of the cuttings to be rooted in solution A for 5 minutes, then transfer them to solution B for 15 minutes. After the treated cuttings have been dried for 5 minutes, they are then planted. Before planting, make holes in the prepared substrate with bamboo chopsticks or a metal rod, and then insert the cuttings into the substrate. The planting depth should be such that the base of the bud on the cutting is just above the ground. Plant the cuttings vertically.

[0108] (4) Post-cutting management: Water thoroughly immediately after cutting to ensure close contact between the cutting and the substrate. Greenhouse management requirements after cutting: Temperature in the greenhouse should be 20-28℃, relative humidity 60-80%, and light and temperature should be controlled with shade netting. Disinfect with an 800-fold dilution of carbendazim solution every 3 days; gradually ventilate, reduce humidity, and increase light after 15 days of cutting.

[0109] (5) After 70 days, the rooting rate and growth were investigated. A total of 50 cuttings were inserted, and the average value of the results was taken.

[0110] According to statistics, the rooting rate was 74%, the diameter of the new shoots was 1.01±0.07mm, and the height of the new shoots was 35.55±3.15cm.

[0111] Comparative Example 4

[0112] The hardwood cuttings of Populus tomentosa include the following steps:

[0113] (1) Cuttings collection: Cuttings are taken in a greenhouse in mid-April. The cuttings are taken from the one-year-old shoots of mature and superior Populus tomentosa trees. The branches with a length of 15cm and a uniform diameter are cut as cuttings to be rooted.

[0114] (2) Substrate treatment: River sand is selected as the cutting substrate. Potassium permanganate solution is used for disinfection. The specific operation is as follows: spray 1.0 wt.% potassium permanganate solution on the solid substrate and mix it evenly with the substrate. Then wrap the substrate with plastic sheeting for 30 minutes, rinse it with clean water, and let it dry for 2 days before use.

[0115] (3) Cutting treatment and propagation: Prepare solution A: a graphene oxide solution with a concentration of 25 mg / L; solution B (rooting solution containing graphene oxide): a mixture of 1 g / L potassium humate and 25 mg / L graphene oxide; each solution is placed in a plastic basin for later use. Soak the base of the cuttings to be rooted in solution A for 5 minutes, then transfer them to solution B for 15 minutes. After the treated cuttings have been dried for 5 minutes, they are then propagated. Before propagation, make holes in the prepared substrate with bamboo chopsticks or a metal rod, and then insert the cuttings into the substrate. The depth of insertion should be such that the base of the bud on the cutting is just above the ground. The cuttings should be inserted vertically.

[0116] (4) Post-cutting management: Water thoroughly immediately after cutting to ensure close contact between the cutting and the substrate. Greenhouse management requirements after cutting: Temperature in the greenhouse should be 20-28℃, relative humidity 60-80%, and light and temperature should be controlled with shade netting. Disinfect with an 800-fold dilution of carbendazim solution every 3 days; gradually ventilate, reduce humidity, and increase light after 15 days of cutting.

[0117] (5) After 70 days, the rooting rate and growth were investigated. A total of 50 cuttings were inserted, and the average value of the results was taken.

[0118] According to statistics, the rooting rate was 70%, the diameter of the new shoots was 0.92±0.09mm, and the height of the new shoots was 34.44±3.23cm.

[0119] The data from Examples 1-6 show that the concentration of graphene oxide in solutions A and B has a significant impact on the rooting rate of plant cuttings. Higher graphene oxide concentrations are not necessarily better. A graphene oxide concentration in solutions A and B within the range of 25–50 mg / L has a good effect on promoting rooting of plant cuttings, resulting in a higher rooting rate. Furthermore, the data from Example 1 and Comparative Example 1 show that the same graphene oxide concentration in solutions A and B promotes rooting better. However, different concentrations result in a weaker rooting effect. This is because a high concentration of solution A can damage the cells of the plant cuttings, affecting the effectiveness of solution B; while a low concentration of solution A can still have some effect, it is slightly less effective than a uniform concentration. As can be seen from the data of Example 1 and Comparative Example 2, treatment with graphene oxide solution followed by treatment with a mixed solution of graphene oxide, ABT1 rooting powder, and potassium humate in Example 1 better promotes rooting of cuttings. However, in Comparative Example 2, treatment with a mixed solution of graphene oxide, ABT1 rooting powder, and potassium humate directly, even with increased graphene oxide concentration, could not achieve the same effect as Example 1. This is because the initial treatment with graphene oxide reduces the influence of endogenous rooting inhibitors on root formation. Only then can graphene oxide promote the absorption of rooting solution by the cuttings. As can be seen from the data of Example 1 and Comparative Examples 3-4, the best rooting effect can only be achieved by the combination of graphene oxide, ABT1 rooting powder and mineral-derived potassium humate in solution B. Without ABT1 rooting powder or mineral-derived potassium humate, the rooting effect will be greatly reduced. This is because graphene oxide has a strong adsorption capacity for large organic molecules, ABT1 rooting powder has a small molecular weight and is relatively simple, and mineral-derived potassium humate can make up for this deficiency. The three work together to promote the rooting of plant cuttings.

[0120] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Various modifications and improvements made by those skilled in the art to the technical solutions of the present invention without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.

Claims

1. A method for promoting rooting of plant cuttings using graphene oxide, characterized in that, Immerse the base of the cuttings to be rooted in a graphene oxide solution, then transfer them to a rooting solution containing graphene oxide. After drying for 5-10 minutes, insert the treated cuttings directly into the substrate. The concentration of graphene oxide in the graphene oxide solution is the same as the concentration of graphene oxide in the rooting solution containing graphene oxide. The rooting solution containing graphene oxide has one of the following two components: (1) 200-500 mg / L LABT1 rooting powder + 1 g / L mineral potassium humate + 25-50 mg / L graphene oxide mixture; (2) 100-500 times diluted rooting powder + 25-50 mg / L graphene oxide mixture. The plant in question is either white poplar or American red smoke tree.

2. The method as described in claim 1, characterized in that, The soaking time in the graphene oxide solution is 4–8 min, and the soaking time in the rooting solution containing graphene oxide is 10–20 min.

3. The method as described in claim 1, characterized in that, The graphene oxide solution contains graphene oxide with an average thickness of 2–4 nm, a sheet diameter of 40–60 nm, 4–6 layers, and a purity >90%.

4. The method as described in claim 1, characterized in that, The cuttings are either softwood cuttings or hardwood cuttings.

5. The method as described in claim 1, characterized in that, The substrate is composed of one or more of peat moss, perlite, vermiculite and river sand. The substrate is disinfected with potassium permanganate solution before cutting.

6. The method as described in claim 1, characterized in that, The specific management procedures after cutting are as follows: water thoroughly immediately after cutting; greenhouse management requirements are a temperature of 20-28℃ and a relative humidity of 60-90%; disinfect every 3 days; gradually ventilate, gradually reduce humidity and increase light after 15 days of cutting.

7. The method as described in claim 5, characterized in that, The specific procedure for disinfecting the substrate is as follows: spray a 0.5-1.0 wt.% potassium permanganate solution onto the solid substrate, mix it evenly with the substrate, then wrap the substrate with plastic sheeting for 20-30 minutes, and then rinse it clean with water.

Images