Method for improving waterlogging tolerance of clematis

Abstract

The application discloses a method for improving waterlogging resistance of Clematis, and comprises the following steps: 1, the cultivation substrate of Clematis potted seedlings adopts peat: coconut bran: perlite: light stone in a ratio of 55:15:15:15; 2, a mixed solution of exogenous growth regulators is configured, the mixed solution comprises 50-100 muM / L mmol / L of melatonin, 1-3 mM / L of Na2SiO3.9H2O2 and 10-30 muM / L of strigolactone, or the mixed solution comprises 1-2 muM / L of brassinolide and 1-3 mM / L of Na2SiO3.9H2O2; 3, the prepared mixed solution of exogenous growth regulators is uniformly sprayed on the upper and lower surfaces of leaves. When Clematis is subjected to waterlogging stress, the method can help to enhance the waterlogging resistance of Clematis, improve the stress resistance of Clematis, promote the growth of Clematis, and lay a foundation for promoting Clematis waterlogging resistance germplasm innovation and new variety breeding.

Description

Technical Field

[0001] This invention relates to the field of agricultural cultivation technology, specifically a method for improving the waterlogging tolerance of clematis. Background Technology

[0002] Clematis, belonging to the genus Clematis in the family Ranunculaceae, is a species of vine that is mostly woody or herbaceous. It is prized for its vibrant colors, diverse flower shapes, and long flowering period, earning it the title of "Queen of Vines" due to its high ornamental value. It is widely used in vertical greening, ground cover, and garden landscaping. my country accounts for approximately 43% of the world's Clematis population, primarily concentrated in central and southwestern my country. Since 1982, wild-type Clematis and foreign cultivars have been introduced and cultivated. However, with the large-scale introduction of Clematis germplasm resources, the issue of varietal adaptability has become increasingly prominent.

[0003] Waterlogging stress has become a major limiting factor in agricultural production due to the continuous deterioration of the global climate. Clematis is most intolerant of waterlogging. Prolonged exposure to saturated or near-saturated soil will cause root rot, wilting and yellowing of leaves, stunted growth, and reduced ornamental quality. In severe cases, it can lead to large-scale plant death, seriously affecting the large-scale production and landscaping applications of clematis. Especially in the Jiangsu and Zhejiang regions, influenced by the monsoon climate, frequent rainfall occurs from April to October each year. This period coincides with the optimal viewing season for clematis. Sustained waterlogging not only drastically reduces the yield of clematis flowers but also greatly increases the likelihood of pests and diseases, even leading to plant death, significantly limiting the promotion and application of clematis.

[0004] Current academic research on waterlogging stress in Clematis is limited. Cai Jin's study on waterlogging stress in horticultural Clematis suggests that waterlogging index, chlorophyll content, MDA, relative conductivity, proline, SOD, POD, Pnmax, LSP, AQY, Pn, Gs, Fv' / Fm', and ERT parameters are strongly correlated with the waterlogging tolerance of Clematis varieties, reflecting differences in waterlogging tolerance and suitable as evaluation factors for Clematis's waterlogging tolerance. As a native species, wild Clematis resources in my country have significant potential for the development and application of resistant varieties. Current research on using exogenous hormones to improve plant resistance has also made some progress. From a practical perspective, the application of exogenous hormones to improve the adverse growth conditions of Clematis has considerable research value and development potential.

[0005] Therefore, it is urgent to develop a cultivation technique that can improve the waterlogging tolerance of clematis, explore the effects of planting conditions and exogenous hormones on the waterlogging tolerance of clematis, and lay the foundation for promoting the innovation of waterlogging-tolerant clematis germplasm and the breeding of new varieties. Summary of the Invention

[0006] The purpose of this invention is to provide a method for improving the waterlogging tolerance of clematis, thereby enhancing the waterlogging tolerance of the ornamental plant, improving its stress resistance, and promoting its growth.

[0007] To achieve the above objectives, the present invention provides the following technical solution:

[0008] A method to improve the waterlogging tolerance of clematis specifically includes: (1) selecting potted clematis seedlings and using a mixed substrate composed of peat, coconut coir, perlite, and pumice; (2) uniformly spraying the leaves with melatonin at a concentration of 50-100 μM / L mmol / L and 1-3 mM / L. A mixed solution of Na2SiO3·9H2O2 and an exogenous growth regulator of strigolactone at a concentration of 10-30 μM / L is prepared by first preparing solutions of the above concentrations separately and then mixing them in equal volume ratios. The method for spraying the exogenous growth regulator is as follows: spraying time is on the day of waterlogging stress, using a fine-drip sprayer to start spraying around 17:00 in the evening, ensuring even spraying on the upper and lower surfaces of the leaves. Spraying time is 3-7 days, from 17:00 to 18:00, each time until both the upper and lower surfaces of the leaves are wet and dripping with water; during this period, the air temperature is 25-35℃ and the relative humidity is 60-70%.

[0009] Furthermore, the waterlogging level under waterlogging stress should be controlled at 3-5 cm above the surface of the substrate, preferably 5 cm.

[0010] Furthermore, select three-year-old clematis potted seedlings with a pot diameter of 10-12cm and a pot height of 15-20cm.

[0011] Furthermore, a mixed matrix consisting of peat, coconut coir, perlite, and pumice in a volume ratio of 55:15:15:15:15 was adopted.

[0012] Furthermore, the leaves are uniformly sprayed with a mixed solution of exogenous growth regulators, consisting of 50 μM / L mmol / L melatonin, 1 mM / L Na2SiO3·9H2O2, and 20 μM / L strigolactone, or a mixed solution of 1 μM / L brassinolide and 1 mM / L Na2SiO3·9H2O2. The mixed solution is prepared by first preparing each of the above concentrations separately and then mixing them in equal volume proportions.

[0013] Furthermore, the method of spraying exogenous growth regulators is to spray for 7 consecutive days, during which the temperature is 30°C and the relative humidity is 60%.

[0014] This invention also provides the following technical solution: a plant growth regulator to improve the waterlogging tolerance of Clematis, wherein the plant growth regulator is a mixed solution of melatonin at a concentration of 50 μM / L mmol / L, Na₂SiO₃·9H₂O₂ at a concentration of 1 mM / L, and strigolactone at a concentration of 20 μM / L; or a mixed solution of brassinolide at a concentration of 1 μM / L and Na₂SiO₃·9H₂O₂ at a concentration of 1 mM / L. And the application of the above growth regulator in any of the following aspects:

[0015] (1) Enhance the antioxidant activity of Clematis plant leaves;

[0016] (2) Increase the chlorophyll content in the leaves of Clematis plants;

[0017] (3) Alleviate leaf damage in Clematis plants;

[0018] (4) Reduce the H2O2 content and MDA content in the leaves;

[0019] (5) Increase the content of soluble sugars and soluble proteins in the leaves of Clematis plants;

[0020] (6) Increase the fresh weight of Clematis plant roots.

[0021] The beneficial effects of this application are:

[0022] 1. Current research on the waterlogging tolerance of Clematis species remains scarce. my country is the country with the richest resources of Clematis species, but the development and utilization of wild Clematis germplasm resources are limited. Therefore, this experiment aims to evaluate the waterlogging tolerance of wild Clematis germplasm resources and horticultural varieties, expand the pool of superior waterlogging-tolerant Clematis germplasm resources, and explore waterlogging-tolerant genes in wild Clematis germplasm resources, providing important basic materials and theoretical basis for waterlogging-resistant breeding of Clematis.

[0023] 2. Studies have shown that exogenous plant regulators such as melatonin play an important role in plant responses to abiotic stress. This study investigated the effects of different concentrations of plant regulators on waterlogged Clematis plants by treating them with different concentrations, exploring the effects of using various regulators alone or in combination on the response of Clematis plants to waterlogging stress, and providing a theoretical basis for the waterlogging-tolerant cultivation and application of Clematis.

[0024] 3. Experimental results showed that the activities of antioxidant enzymes (APX, CAT, POD) in Clematis tiantai under waterlogging stress were significantly increased. Melatonin treatment further increased the antioxidant enzyme activity, proline content, and chlorophyll content of Clematis leaves, as well as reduced the relative electrical conductivity of the leaves, with a concentration of 50 μmol·L⁻¹. -1Melatonin treatment resulted in the highest activity. Waterlogging stress caused damage to the leaves of *Clematis tiantaiensis* after flooding, leading to yellowing and leaf drop. Exogenous application of melatonin could alleviate this damage to some extent. In practical observations, we found that applying only one type of melatonin resulted in significant differences in waterlogging tolerance among different *Clematis tiantaiensis* varieties. For example, varieties with strong waterlogging tolerance required higher melatonin concentrations; *Clematis tiantaiensis* and *Clematis bononia*, which are relatively waterlogged-tolerant, required melatonin concentrations around 200 μmol·L⁻¹. -1 For varieties like the hairy-leafed and wind-forest types that are not tolerant of waterlogging, the melatonin concentration is 50-100 μmol·L⁻¹. -1 Ideally, we should further explore suitable methods to improve the waterlogging tolerance of most clematis varieties.

[0025] 4. From the perspective of leaf appearance, the leaves of Clematis 'Golden Buddha' and Clematis 'Ice Beauty' suffered some damage after waterlogging stress, turning yellow and falling off. Exogenous spraying of melatonin, brassinolide, and strigolactone was effective. However, we unexpectedly found that the combined application of silicon treatment significantly alleviated the damage caused by waterlogging stress. In contrast, the effects of phosphorus and potassium on alleviating waterlogging stress were not significant. The combination of 50 μM / L melatonin + 20 μM / L strigolactone + 1 mM / L Na2SiO3·9H2O2, or the combination of 1 μM / L brassinolide + 1 mM / L Na2SiO3·9H2O2, showed better results.

[0026] 5. Physicochemical analysis of leaves showed that under waterlogging stress, the combined application of plant growth regulators in Clematis chinensis significantly increased the total antioxidant capacity (T-AOC) activity, growth regrowth (GR) activity, and the content of soluble sugars and proteins. Simultaneously, it reduced the H2O2 and MDA content in the leaves. The combination of 1 μM / L brassinolide + 1 mM / L Na2SiO3·9H2O2 showed the best effect; the combination of 50 μM / L melatonin + 20 μM / L strigolactone + 1 mM / L Na2SiO3·9H2O2 showed the highest activity, superior to any single or two applications.

[0027] 6. In addition to the combined application of exogenous plant growth regulators, we also improved the root growth environment by adjusting the mixed substrate ratio, waterlogging level, air temperature and humidity, and the number of days of stress, thereby promoting the root growth of Clematis under waterlogging stress. Combined with the combined application of growth regulators, it has a good effect on increasing the fresh weight of Clematis roots under waterlogging stress. The mixed substrate composed of peat, coconut coir, perlite, and pumice in a volume ratio of 55:15:15:15; waterlogging stress for 7 days, with the waterlogging level controlled at 5cm above the surface of the substrate; the highest fresh weight of Clematis roots was achieved when the air temperature was 30℃ and the relative humidity was 60%. Attached Figure Description

[0028] Figure 1 Effects of different melatonin gradients on the activities of APX, CAT, and POD in Clematis tiantaiensis;

[0029] Figure 2 Effects of different melatonin gradients on proline content and relative conductivity of Clematis tsao-tai;

[0030] Figure 3 The effect of different melatonin gradients on the chlorophyll content of Clematis tsao-tai leaves;

[0031] Figure 4 The effect of different melatonin gradients on the degree of leaf damage in Clematis tiantai after flooding stress;

[0032] Figure 5 The effects of different plant growth regulators on the degree of leaf damage in Clematis 'Ice Beauty' after flooding stress;

[0033] Figure 6 The effects of different plant growth regulators on the degree of leaf damage in Clematis jinfoenum after flooding stress;

[0034] Figure 7 The effects of different plant growth regulators on the physicochemical properties of Clematis jinfoenum-graecum leaves after flooding stress; Detailed Implementation

[0035] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0036] Example 1

[0037] A method to improve the waterlogging tolerance of clematis includes: (1) selecting three-year-old potted clematis seedlings and using a mixed substrate composed of peat moss, coconut coir, perlite, and pumice in a volume ratio of 55:15:15:15; (2) controlling the waterlogging level to be 5cm above the surface of the substrate during waterlogging stress; and uniformly spraying the leaves with a concentration of 50μM / L. A mixed solution of melatonin at mmol / L, Na2SiO3·9H2O2 at 1M / L, and strigolactone at 20μM / L was prepared by first preparing the solutions of the above concentrations separately and then mixing them in equal volume ratios. The method for spraying the exogenous growth regulator was as follows: spraying was carried out on the day of waterlogging stress, using a fine-drip sprayer starting at around 17:00 in the evening, ensuring even spraying on the upper and lower surfaces of the leaves. Spraying continued for 7 days, from 17:00 to 18:00, each time ensuring that both the upper and lower surfaces of the leaves were wetted and dripping with water; the temperature during this period was 30℃ and the relative humidity was 60%.

[0038] Example 2

[0039] A plant growth regulator to improve the waterlogging tolerance of clematis, wherein the plant growth regulator is a mixed solution of melatonin at a concentration of 50 μM / L mmol / L, Na2SiO3·9H2O2 at a concentration of 1 mM / L, and strigolactone at a concentration of 20 μM / L.

[0040] Example 3

[0041] A plant growth regulator to improve the waterlogging tolerance of Clematis, wherein the plant growth regulator is a mixed solution of brassinolide at a concentration of 1 μM / L and Na2SiO3·9H2O2 at a concentration of 1 mM / L.

[0042] Experiment 1: Effect of melatonin on the waterlogging tolerance of Clematis chinensis

[0043] Experimental Methods: Wild-type Clematis germplasm resources from Tiantai were selected. Waterlogging treatment was performed using the method described in Example 1, with the plant growth regulators replaced as follows. The waterlogging level was controlled to be 5 cm above the topsoil. Five control groups were set up: blank control (CK), melatonin 0 μmol·L⁻¹, and control group 2.5. -1 (T0), melatonin 50 μmol·L -1 (T1), melatonin 100 μmol·L -1 (T2), melatonin 200 μmol·L -1(T3). During the treatment period, water was replenished regularly to maintain the water level, while the control group received normal water management. Melatonin was applied via foliar spraying, and the treatment period was from the start of stress to day 7. Ten pots were treated in each group, and the experimental period was 28 days. Physiological indicators were sampled at 7:00 AM, and intact, healthy leaves from the plants were selected and mixed for sampling and brought back to the laboratory for physiological indicator measurement. The study investigated the effects of different concentrations of exogenous melatonin on the physiological indicators of Clematis clematis after waterlogging stress; corresponding to the blank control group and waterlogging stress group of Clematis clematis in the experiment, 5 plants were sampled in each group, and each sample was replicated in 3 triplicates.

[0044] Experimental results:

[0045] Figure 1 As shown, the experimental results indicate that the activities of antioxidant enzymes (APX, CAT, POD) in Clematis tiantai under waterlogging stress were significantly increased. Melatonin treatment further enhanced the activity of antioxidant enzymes, with a concentration of 50 μmol·L⁻¹. -1 Melatonin treatment resulted in the highest activity.

[0046] Figure 2 As shown, waterlogging stress led to an increase in proline content in the leaves of Clematis tiantaiensis (50 μmol·L⁻¹). -1 Melatonin treatment further increased proline content, but proline content decreased significantly with increasing melatonin concentration. Waterlogging stress led to an increase in leaf relative conductivity. The relative conductivity of leaf cells in the melatonin-treated group was lower than that in the waterlogging-only treatment group, with T1 (50 μmol·L⁻¹) being the highest. -1 The group with the lowest relative conductivity is group ).

[0047] Figure 3 As shown, waterlogging stress significantly reduced the chlorophyll content in the leaves of Clematis tiantaiensis, and melatonin treatment could increase the chlorophyll content, with T1 (50 μmol·L⁻¹) being the most effective. -1 The highest chlorophyll content was observed in the leaves under the first treatment group.

[0048] Figure 4 As shown, waterlogging stress caused some damage to the leaves of Clematis tiantaiensis after flooding, resulting in yellowing and leaf drop. Exogenous application of melatonin could alleviate the damage caused by waterlogging stress to some extent, with T1 (50 μmol·L⁻¹) being the most effective. -1 The leaf damage was minimal under the treatment group )

[0049] Experiment 2: Effects of different plant growth regulators on the waterlogging tolerance of Clematis

[0050] Experimental Methods: After establishing the effect of melatonin in alleviating waterlogging stress in Clematis chinensis, to further investigate the effects of different plant growth regulators on the waterlogging tolerance of Clematis chinensis, and to identify the most suitable environmental factors and different regulators or combinations thereof for improving the waterlogging tolerance of Clematis chinensis, we further selected wild-type Clematis chinensis (Golden Buddha Clematis) and horticultural cultivar Clematis chinensis (Ice Beauty) for waterlogging treatment using the method described in Example 1, with the plant growth regulators replaced as shown in Table 1 below. Ten pots were used in each treatment group. During the treatment period, water was replenished regularly to maintain the water level, while the control group received normal water management. Different plant growth regulators were applied via foliar spraying, and the treatment period lasted from the start of stress to day 7. External morphological observations were recorded on days 7, 14, 21, and 28 of treatment, and mature leaves from the upper and middle parts of the plants were also measured until the end of the experimental period. The experiment lasted for 28 days. Physiological indicators were sampled at 7:00 am. Intact and healthy leaves of the plants were selected and mixed for sampling and brought back to the laboratory for physiological indicator measurement to explore the effects of different exogenous regulators on the physiological indicators of Clematis clematis after waterlogging stress. Corresponding to the blank control group and waterlogging stress group of Clematis clematis in the experiment, 5 plants were sampled in each group, and each sample was replicated 3 times.

[0051] Table 1 Experimental groups with different exogenous plant growth regulators

[0052] serial number deal with Spraying exogenous plant growth regulators A control group none B Flooding Distilled water instead of exogenous growth regulators C Flooding 1 μM / L brassinolide D Flooding 50μM / L melatonin E Flooding 20 μM / L strigolactone F Flooding 50 μM / L salicylic acid G Flooding <![CDATA[1 mM / L Na2SiO3·9H2O2 (silicon treatment)]]> H Flooding <![CDATA[0.3 mM / L KH2PO4 (phosphorus treatment)]]> I Flooding <![CDATA[1 mM / L K2O4 (Potassium treatment)]]> J Flooding <![CDATA[50 μM / L melatonin + 20 μM / L strigolactone + 1 mM / L Na2SiO3·9H2O2]]> K Flooding <![CDATA[50 μM / L melatonin + 1 mM / L Na2SiO3·9H2O2]]> L Flooding 50 μM / L melatonin + 20 μM / L strigolactone M Flooding <![CDATA[1 mM / L Na2SiO3·9H2O2 + 20 μM / L strigolactone]]> N Flooding <![CDATA[1 μM / L brassinolide + 1 mM / L Na2SiO3·9H2O2]]>

[0053] Experimental results:

[0054] Figure 5-6 As shown, different plant growth regulators have different effects on the waterlogging tolerance of Clematis 'Golden Buddha' and 'Ice Beauty'. The leaves of Clematis 'Golden Buddha' and 'Ice Beauty' suffered some damage after waterlogging stress, turning yellow and falling off. Exogenous spraying of melatonin, strigolactone, and silicon treatment can alleviate the damage caused by waterlogging stress to some extent. Phosphorus and potassium have no significant effect on alleviating waterlogging stress. The combination of 50 μM / L melatonin + 20 μM / L strigolactone + 1 mM / L Na2SiO3·9H2O2, or the combination of 1 μM / L brassinolide + 1 mM / L Na2SiO3·9H2O2, showed better results.

[0055] Figure 7As shown, the physicochemical analysis data of the leaves indicated that, under waterlogging stress, the combined application of plant growth regulators significantly increased the total antioxidant capacity (T-AOC) activity (U / mgprot), GR growth activity (U / gprot), soluble sugar (mg / g), and soluble protein (mg / g) content in Clematis jinfoenum-graecum. This suggests that the treatment with plant growth regulators can further enhance the activity of antioxidant enzymes in Clematis jinfoenum-graecum ... The combination of 50 μM / L melatonin, 20 μM / L strigolactone, and 1 mM / L Na2SiO3·9H2O2 showed the highest activity after treatment, which was better than any one or two of them. The combination of 1 μM / L brassinolide and 1 mM / L Na2SiO3·9H2O2 was also more effective than either of them alone.

[0056] Experiment 3: Effects of different environmental conditions on improving the waterlogging tolerance of Clematis chinensis

[0057] Experimental method: The Wind Forest Clematis variety was selected and waterlogging treatment was carried out using the method in Example 1. At the same time, the corresponding environmental parameters were replaced. The specific treatment is shown in the table below. Each group consisted of 10 pots, and the experimental period was 28 days. Plant samples were collected at 7:00 am on the day the period ended.

[0058] Table 2. Effects of different environmental conditions on Clematis leaves and roots under flood stress.

[0059]

[0060]

[0061] Experimental results:

[0062] In combination with the application of two different formulations of exogenous plant growth regulators (Examples 2 and 3), we also studied the effects of substrate ratio, waterlogging height, air temperature and humidity, and number of days of stress on improving the waterlogging resistance of Clematis cultivars. The main study focused on the effects of the above cultivation and management conditions on the root growth of Clematis after flooding. By adjusting the mixed substrate ratio, waterlogging height, air temperature and humidity, the root growth of Clematis could be alleviated. Combined with the combined application of the growth regulator, it had a good effect on improving the fresh weight of Clematis roots under waterlogging stress. The mixed substrate composed of peat, coconut coir, perlite, and pumice in a volume ratio of 55:15:15:15 was more effective in improving the water absorption and permeability of the Clematis substrate. This substrate formulation could promote the growth of Clematis root biomass. After 7 days of waterlogging stress (waterlogging height 5cm) + application of the growth regulator, the Clematis roots showed significant drought and waterlogging resistance, and the fresh weight of the plant roots was comparable to that of the CK control.

[0063] Furthermore, during waterlogging stress, adjusting the temperature and humidity in the greenhouse can further promote clematis root development. The highest fresh weight of clematis roots was observed when the air temperature was maintained at 30℃ and the relative humidity at 60% during the stress period. Both excessively low temperatures and excessively high humidity are detrimental to clematis root growth under waterlogging stress.

[0064] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A method of increasing the fresh weight of Clematis root under waterlogging stress, characterized in that, Specifically comprising (1) selecting Clematis potted seedlings, adopting a mixed substrate composed of peat, coconut husk, perlite and light stone, with a volume ratio of 55:15:15:15; (2) controlling the waterlogging position to be 5 cm higher than the surface of the substrate during waterlogging stress; uniformly spraying the leaf surface with a mixed solution of exogenous growth regulators with a concentration of 1 μM / L of brassinolide and 1 mM / L of Na2SiO3·9H2O2, wherein the mixed solution is prepared by mixing the solutions with the above-mentioned concentrations in equal proportions; ensuring the water level by supplementing water at regular intervals during the treatment; and spraying the exogenous growth regulators by spraying at 17:00 in the evening on the day of encountering waterlogging stress using a fine droplet sprayer, uniformly spraying the upper and lower surfaces of the leaves, spraying for 7 days, spraying at 17:00-18:00, and ensuring that the leaf surface and back are wet and dripping each time; the air temperature is 30°C, and the air relative humidity is 60% during the spraying.

2. A method of improving the waterlogging tolerance of Clematis, characterized by, Specifically comprising (1) selecting Clematis potted seedlings, adopting a mixed substrate composed of peat, coconut husk, perlite and light stone; (2) uniformly spraying the leaf surface with a mixed solution of exogenous growth regulators with a concentration of 50 μM / L of melatonin, 1 mM / L of Na2SiO3·9H2O2 and 20 μM / L of strigolactone, wherein the mixed solution is prepared by mixing the solutions with the above-mentioned concentrations in equal proportions; ensuring the water level by supplementing water at regular intervals during the treatment; and spraying the exogenous growth regulators by spraying at 17:00 in the evening on the day of encountering waterlogging stress using a fine droplet sprayer, uniformly spraying the upper and lower surfaces of the leaves, spraying for 7 days, spraying at 17:00-18:00, and ensuring that the leaf surface and back are wet and dripping each time; the air temperature is 30°C, and the air relative humidity is 60% during the spraying; and the improved waterlogging resistance of Clematis specifically refers to improving the total antioxidant capacity (T-AOC) activity, GR growth activity, chlorophyll content, soluble sugar content and soluble protein content of the leaves of Clematis, and simultaneously reducing the H2O2 content and MDA content of the leaves.

3. A method as claimed in claim 1 or 2, characterised in that, Three-year-old Clematis potted seedlings are selected, with a pot diameter of 10-12 cm and a pot height of 15-20 cm.

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