A cultivation method for improving the heat tolerance of alnus nitida

Abstract

The application provides a cultivation method for improving heat resistance of gnetum gnemon, and relates to the technical field of horticultural flower cultivation.The application comprises the following steps: layering planting of gynostemma pentaphyllum, gnetum gnemon and passionflower edulis, hanging bird's nest fern potting on a shed frame, and spraying of rare earth cerium and potassium silicate solution.The layering planting of gynostemma pentaphyllum, gnetum gnemon and passionflower edulis, and the hanging bird's nest fern potting on the shed frame can improve the soil porosity and water content of the planting area, reduce the ground surface temperature of the planting area in summer, and improve the unit area output value;on the basis of the layering planting, the spraying of the rare earth cerium and the potassium silicate solution can reduce the relative electrical conductivity and the malondialdehyde content of the gnetum gnemon leaves, improve the chlorophyll content, improve the Pn and Tr of the gnetum gnemon leaves, improve the average activities of the SOD, the POD and the CAT of the leaves, and improve the survival rate.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of horticulture, in particular to a flower cultivation method, and more particularly to a cultivation method for improving the heat tolerance of Heuchera. BACKGROUND

[0002] Heuchera is a perennial herb with high ornamental value, widely used in landscaping, flower arrangement and potted ornamental due to its rich leaf color and shade tolerance. However, Heuchera is native to the cool and humid environment of North America and is extremely sensitive to high temperature (> 30℃). It performs poorly in tropical, subtropical and temperate summer hot regions. High temperature stress can cause leaf scorching, discoloration, growth stagnation, and even whole plant death of Heuchera, severely limiting its commercial application range.

[0003] With global warming, extreme high temperature weather occurs frequently, and the survival rate and ornamental quality of Heuchera in summer have decreased significantly, causing huge economic losses to the landscaping industry. For example, in southern China, high summer temperatures (35–40℃) result in a mortality rate of Heuchera of more than 50%, severely restricting its market promotion. Therefore, improving the heat tolerance of Heuchera has become a key direction of horticultural breeding and cultivation technology research.

[0004] Currently, the main methods to improve the heat tolerance of Heuchera include variety selection, cultivation regulation and exogenous substance treatment, but these methods have obvious shortcomings:

[0005] (1) Traditional breeding cycle is long, and it is difficult to balance heat tolerance and ornamental value

[0006] It usually takes 5–8 years to screen heat-tolerant varieties through hybridization breeding, and heat-tolerant varieties often have lighter leaf color or weaker growth, affecting commercial value. For example, some heat-tolerant Heuchera varieties (such as ‘Southern Comfort’) have green leaf discoloration under high temperature, reducing ornamental value.

[0007] (2) High cost of cultivation regulation, difficult to apply on a large scale

[0008] Shading, sprinkling irrigation to reduce temperature or soil improvement (such as adding water-retaining agents) can alleviate high temperature damage, but require continuous manual intervention, consume a lot of energy and water resources, and do not meet the sustainable development needs of modern horticulture.

[0009] (3) Existing exogenous substance treatment has unstable effect or environmental risk

[0010] The exogenous substances that have been studied more include abscisic acid (ABA) and nanomaterials, but these methods have the following problems:

[0011] Concentration dependence: for example, ABA can improve heat tolerance at low concentrations (<100 μM), but high concentrations inhibit growth;

[0012] Short-term effect: repeated application is required, and the heat tolerance cannot be maintained for a long time;

[0013] Environmental risk: some nano materials (such as nano cerium oxide) may cause soil pollution.

[0014] Therefore, it is urgent to develop an efficient, stable and environmentally friendly method to improve the heat tolerance of alunite roots. SUMMARY

[0015] The technical solution adopted by the present application to solve its technical problems is:

[0016] A cultivation method for improving the heat tolerance of alunite roots, comprising the following steps:

[0017] Step one. In early March, gynostemma pentaphyllum is cut and planted in the bottom layer of the alunite root planting area according to a plant spacing of (35-50) cm x (35-50) cm.

[0018] Each alunite root planting area is equipped with two seedbeds with a length of (4-5) m x a width of (1-2) m and a height of 60-80 cm. Three-year-old alunite roots with a crown width of 12-18 cm are placed in the seedbeds for cultivation in early March, and the plant spacing is (18-25) cm x (18-25) cm. Passiflora edulis is cultivated in a greenhouse in early March. Each alunite root planting area has a size of (4-5) m x (4-5) m.

[0019] Step two. The Passiflora edulis cultivated in the greenhouse is transplanted to the alunite root planting area in mid-to-late April. One Passiflora edulis is planted in each alunite root planting area. The length of the vine is 40-60 cm. The spacing between the support posts of the Passiflora edulis trellis is (4.5-5.5) m x (4.5-5.5) m, and the height is 2.3-2.7 m. Angle steel is used for welding the top crossbeam, and a net with a mesh size of (8-12) cm x (8-12) cm is hung on the crossbeam.

[0020] Bird's nest ferns are hung on the trellis. The pot diameter is 18-25 cm, the pot height is 18-25 cm, the crown width is 40-60 cm, and the seedling height is 40-60 cm. The hanging spacing is (1.8-2.2) m x (1.8-2.2) m, calculated from the center of the bird's nest fern plant. The distance from the pot bottom to the ground is 1.2-1.5 m.

[0021] Step three. Rare earth cerium solution is sprayed on the alunite roots in summer. The spraying conditions of the rare earth cerium solution are as follows: after the average daily temperature exceeds 30℃ for 7 consecutive days, the spraying is carried out in the morning of the next day. First, uniformly spray 200-400 mg / L potassium silicate solution on the leaves of the alunite roots until the leaves are wet but not dripping. After 3-5 hours, spray 50-200 mg / L rare earth cerium solution.

[0022] Further, in step one, the garden in the bottom layer of the alunite root planting area is weeded and plowed. Every 100 m 2Apply 140-160 kg of sheep manure and 250-350 kg of peat soil for base improvement, evenly spread on the ground surface; deep plowing 20-40 cm, fully mix sheep manure, peat soil and plowing layer soil; flatten the soil surface, break the soil clumps, and prepare for seedling transplanting.

[0023] Further, during the planting of the alum root, water and fertilizer integration planting is adopted, an automatic irrigation nozzle is arranged on the top layer of the shed frame, uniform irrigation from the top layer to the bottom layer is ensured, irrigation is carried out twice a day in winter and spring, and irrigation is carried out three times a day in summer and autumn.

[0024] Further, in step two, the alum root variety is one or a combination of "Golden Zebra", "Berry Fruit" and "Eternal Purple".

[0025] Further, in step three, the rare earth cerium solution is a cerium nitrate solution.

[0026] Further, in step three, the rare earth cerium solution is sprayed on the leaf surface of the alum root.

[0027] The effects of the invention in planting gynostemma in the bottom layer include:

[0028] (1) Improve soil structure: gynostemma as a bottom layer cover plant, combined with sheep manure and peat soil deep plowing 30 cm, its root system can increase soil porosity and improve water retention capacity. (2) Reduce ground temperature: gynostemma grows creeping, forms a dense litter layer, reduces sunlight direct radiation to the soil, thereby reducing the ground temperature of the planting area in summer, and indirectly alleviating the heat stress on the alum root. (3) Water regulation: through stratified planting and water and fertilizer integrated irrigation, gynostemma can help maintain soil humidity and avoid excessive water loss due to high temperature and drought.

[0029] The effects of the invention in planting passion fruit in the top layer include: (1) Physical shading and cooling: passion fruit shed frame is high, and the vines cover form a light-blocking layer to block strong light direct radiation and reduce the leaf surface temperature of the middle layer alum root. (2) Microclimate regulation: passion fruit leaf transpiration increases air humidity, alleviates the stomatal closure pressure of the alum root caused by high temperature and dryness, and creates a suitable shady microclimate for the growth of the alum root. (3) Economic and space utilization: passion fruit as an economic crop has the characteristics of climbing growth, fully utilizes the vertical space, and the stratified planting mode (bottom layer gynostemma / middle layer alum root / top layer bird nest fern+passion fruit) improves the output efficiency per unit area.

[0030] The effect of the invention of hanging bird nest fern potted includes: hanging bird nest fern potted on the shed, creating a distance, uniform coverage "sun umbrella" type shade, combined with the upper layer of passion fruit, the lower layer of gynostemma and alum root, forming a high-efficiency complex ecosystem. Not only can it directly filter strong light, but also can significantly increase humidity through the combined transpiration of plant communities, and can produce a synergistic effect with the spraying of rare earth cerium, and jointly act on reducing the membrane lipid peroxidation level of alum root cells, and comprehensively improve the heat resistance.

[0031] The effect of the invention of spraying rare earth cerium includes: (1) relieving membrane system damage: reducing the relative electrical conductivity and malondialdehyde (MDA) content of leaves, indicating that rare earth cerium can reduce the cell membrane lipid peroxidation caused by high temperature, and protect the integrity of cell membrane. (2) Enhancing photosynthetic capacity: increasing chlorophyll content, promoting light energy capture; at the same time, improving net photosynthetic rate (Pn), transpiration rate (Tr), and improving photosynthetic efficiency under high temperature. (3) Activating antioxidant enzyme system: improving the activities of superoxide dismutase (SOD), peroxidase (POD) and catalase (CAT), enhancing the ability of alum root to remove active oxygen, and reducing high temperature oxidative stress.

[0032] The invention of spraying potassium silicate can strengthen the cell wall, reduce the mechanical damage caused by high temperature, form silicified cells, increase the mechanical strength of plant cell wall, and play a natural "mechanical or physical barrier" role. It can effectively shield water or water vapor penetration, maintain the stability of cell membrane structure and function, reduce plant wilting and transpiration, and maintain the stability of cell membrane structure and function, so as to reduce leaf water consumption and reduce respiration rate. Potassium silicate is a strong base, and separate use can easily burn the leaves. Rare earth ions can combine with the phospholipid of cell membrane, regulate calcium metabolism, and replace Ca 2+ related to Ca 2+ , participate in many physiological processes related to Ca , so rare earth ions can maintain the permeability and stability of cell membrane, improve the protection function of cell membrane, and enhance the resistance of crops to adverse environment. Rare earth cerium element can promote the stability of cell wall and membrane structure, enhance the protection ability of plant cells to external environment, also can improve the activity of antioxidant enzyme, reduce the degree of oxidative damage, thereby slow down the occurrence of cell oxidative stress. Through inducing stress information transmission and regulating the expression of stress resistance genes, the plant can make more effective physiological response under stress conditions. Rare earth cerium treatment slows down the damage to cell membrane caused by high temperature stress; can promote the accumulation of permeating substances and stabilize the osmotic regulation balance; promotes the photosynthetic rate under high temperature stress. Since potassium silicate has reduced leaf temperature and water loss by physical means, otherwise the plant has been severely dehydrated and the cell has been damaged due to high temperature, the effect of cerium will be greatly reduced. The two are used together to form a complementary and synergistic mechanism of "physical defense + biochemical reaction".

[0033] Compared with the background art, the technical scheme of the present application has the following advantages:

[0034] Currently, there is no report on the research of rare earth elements improving the heat resistance of alum root. The present application proposes to treat alum root with cerium nitrate, significantly improve its heat resistance by regulating the antioxidant system, photosynthesis and heat shock protein expression. The core advantages of the present application include: high efficiency: compared with the traditional method, the survival rate of the tested alum root variety at 30 DEG C can be increased by 30%-50% by layering planting and rare earth treatment; low cost: cerium is a high-abundance rare earth element, and the raw material is cheap, which can be suitable for large-scale application; environmental protection: avoiding the use of high-concentration chemical hormones or transgenic technology, which meets the green agricultural development trend.

[0035] The cultivation method of the present application constructs a microenvironment regulation system by layering planting (Gynostemma pentaphyllum-alum root-Asparagus fern-passion fruit), and combines the physiological regulation of rare earth cerium and potassium silicate solution to synergistically improve the heat resistance, photosynthetic efficiency and antioxidant capacity of alum root, form a "physical-physiological" heat resistance defense system, and realize stable yield and high quality in high temperature season. The popularization and application of the present application can significantly expand the planting range of alum root in high temperature areas. DETAILED DESCRIPTION

[0036] Example 1

[0037] 1. The test design of the nursery (Xiamen) is as follows: the nursery area is 100 m 2 , the length and width are 10 m respectively, two longitudinal and transverse garden roads with a width of 0.8 m are set, the nursery is evenly divided into four 4.6 m x 4.6 m test plots, weeds are removed, the land is prepared, 150 kg of sheep manure and 300 kg of peat soil are applied, deep plowing is performed to a depth of 30 cm, and seedlings are leveled. Remove field weeds to ensure a clean surface; apply 150 kg of decomposed sheep manure and 300 kg of peat soil as base application, evenly spread on the ground; deep plowing to a depth of 30 cm, mix the sheep manure, peat soil and plowing layer soil thoroughly; level the soil surface, break up the soil clods, and prepare for seedling transplanting. Water and fertilizer integration planting is adopted, spray heads with a spray diameter of 30 m are set on the top shelf to automatically irrigate, the interval is 10 m, to ensure uniform irrigation from the top to the bottom, 2 times a day in winter and spring, and 3 times a day in summer and autumn. The sprayed fertilizer is "Manxu" intelligent farm water-soluble fertilizer (microelement type) of Bosengyuan Company, and the concentration is according to the recommended method on the package.

[0038] 2. In early March, gynostemma pentaphyllum is cut and planted in the bottom layer of the test area according to a plant spacing of 40 cm x 40 cm, the cutting depth is about 5 cm, the leaves are oriented uniformly, and the cuttings are irrigated thoroughly after cutting.

[0039] Each test plot is installed with 2 4.6m*1.6m seedbeds, 70cm high, taking three-year-old crown width of about 15cm Gmelina hainanensis 'Golden Zebra', 'Berry' and 'Eternal Purple' as the research object, placed in the seedbed in early March, and the plant spacing is 20cm*20cm.

[0040] In early March, the passion fruit was cultivated in the greenhouse, and in mid-to-late April, it was transplanted to the test area. Each test plot planted one passion fruit with a vine length of 50cm. The spacing between the support posts of the passion fruit trellis was 5m*5m, and the height was 2.5m. Angle steel was used to weld the top crossbeam, and a net with a mesh size of 10cm*10cm was hung on the crossbeam.

[0041] Bird's nest ferns were hung on the trellis, with a pot diameter of 20cm and a pot height of 20cm. The crown width was about 50cm, and the seedling height was about 50cm. The hanging distance was 2m*2m, calculated from the center of the bird's nest fern plant, providing shade while ensuring adequate light. The pot was placed 1.4m above the ground, which was suitable for bird's nest fern leaf picking. A "sun umbrella" type shade was created with a moderate distance and uniform coverage, which combined with the upper layer of passion fruit and the lower layer of gynostemma pentaphyllum and gmelina hainanensis to form a high-efficiency complex ecological system.

[0042] 3. The spraying conditions of the rare earth cerium solution are as follows: in summer, spray in the morning when the average daily temperature exceeds 30℃ for 7 consecutive days (i.e. after the average daily temperature exceeds 30℃ for 7 consecutive days in summer, spray in the morning of the next day). First, uniformly spray the gmelina hainanensis leaves with a 300mg / L potassium silicate solution until the leaves are wet but not dripping. After 4 hours, spray the rare earth cerium solution. The rare earth cerium solution is a cerium nitrate solution. The concentration of the rare earth cerium solution for gmelina hainanensis leaf spraying is 100mg / L.

[0043] After 3 months of high temperature, the soil-related indicators were measured; after 5 days of spraying the rare earth cerium solution, the leaf physiological indicators were measured. The measurement methods are as follows:

[0044] Malondialdehyde (MDA) content determination (thiobarbituric acid method), conductivity determination (conductivity meter method), soluble protein content determination (Coomassie brilliant blue method), soluble sugar content determination (anthrone method), chlorophyll content determination (spectrophotometric method), catalase (CAT) activity determination (ultraviolet absorption method), peroxidase (POD) activity determination (guaiacol method), superoxide dismutase (SOD) activity determination (nitro blue tetrazolium (NBT) method), and average net photosynthetic rate (Pn) and average transpiration rate (Tr) of leaves were determined using a Yaxin-1105 portable photosynthesis fluorometer

[0045] The control group was not treated, and the control group plot also installed 2 4.6m x 1.6m seedbeds, 70cm high, with three-year-old crown width of about 15cm "Golden Zebra", "Berry" and "Eternal Purple" potted roots as research objects, placed in the seedbed in early March, with a plant spacing of 20cm x 20cm. But the control group did not plant Gynostemma pentaphyllum, bird nest fern, passion fruit, and did not spray cerium solution and potassium silicate solution, and other garden treatment, water and fertilizer treatment and management methods were the same as the test group.

[0046] Experimental results:

[0047] The test area ground soil porosity increased by 2-4%, the average soil moisture content increased by 1-2%, and the surface temperature of the test area decreased by 4-6℃ in summer.

[0048] "Golden Zebra" potted root: see Table 1, the average malondialdehyde (MDA) content of the leaf decreased by about 5.6%, the average relative conductivity decreased by about 20.8%, the average soluble protein content increased by about 18.6%, and the average soluble sugar content increased by about 26.5%. The average chlorophyll a content of the leaf increased by about 7.8%, and the average chlorophyll b content increased by about 8.2%. The average net photosynthetic rate (Pn) of the leaf increased by about 9.5%, and the average transpiration rate (Tr) increased by about 16.2%. The average catalase (CAT) activity of the leaf increased by about 10.2%, the average peroxidase (POD) activity increased by about 35.5%, and the average superoxide dismutase (SOD) activity increased by about 23.9%.

[0049] Table 1 "Golden Zebra" experimental results

[0050]

[0051] "Berry" potted root: see Table 2, the average malondialdehyde (MDA) content of the leaf decreased by about 7.2%, the average relative conductivity decreased by about 21.2%, the average soluble protein content increased by about 17.5%, and the average soluble sugar content increased by about 28.6%. The average chlorophyll a content of the leaf increased by about 8.9%, and the average chlorophyll b content increased by about 7.6%. The average net photosynthetic rate (Pn) of the leaf increased by about 20.3%, and the average transpiration rate (Tr) increased by about 36.6%. The average catalase (CAT) activity of the leaf increased by about 15.6%, the average peroxidase (POD) activity increased by about 20.5%, and the average superoxide dismutase (SOD) activity increased by about 21.6%.

[0052] Table 2 "Berry" experimental results

[0053]

[0054] Alum root "eternal purple": see Table 3, the average malondialdehyde (MDA) content of the leaves is reduced by 6.9%, the average relative conductivity is reduced by 23.9%, the average soluble protein content is increased by 19.6%, and the average soluble sugar content is increased by 27.1%. The average chlorophyll a content of the leaves of the alum root is increased by 8.8%, and the average chlorophyll b content is increased by 7.1%. The average net photosynthetic rate (Pn) of the leaves is increased by 38.1%, and the average transpiration rate (Tr) is increased by 25.2%. The catalase (CAT) activity of the leaves is increased by 19.8%, the average peroxidase (POD) activity is increased by 28.5%, and the average superoxide dismutase (SOD) activity is increased by 25.6%.

[0055] Table 3 "eternal purple" experimental results

[0056]

[0057] After the summer, the survival rate was measured, wherein the "golden zebra" survival rate was about 83%, which was increased by about 31 percentage points compared with the control group (the survival rate of the golden zebra control group was about 52%); the "berry" survival rate was about 75%, which was increased by about 33 percentage points compared with the control group (the survival rate of the berry control group was about 42%); the "eternal purple" survival rate was about 69%, which was increased by about 41 percentage points compared with the control group (the survival rate of the "eternal purple" control group was about 28%).

[0058] In summary, the present application combines complex ecological system construction and exogenous substance regulation through a "physical-physiological" synergistic mechanism, forming a set of efficient, stable and environmentally friendly comprehensive cultivation scheme for improving the heat resistance of alum root. The advantages mainly lie in the synergistic effect of the following three aspects:

[0059] I. Synergy of spatial structure and microclimate regulation: the present application establishes a three-dimensional layered planting mode of "gynostemma (bottom layer)-alum root (middle layer)-bird nest fern + passion fruit (top layer)". This mode is not a simple stacking of plants, but a high-efficiency complex ecological system, achieving the synergy of physical shading and microclimate regulation. The upper layer of passion fruit shelf and suspended bird nest fern together form an adjustable "sunshade umbrella", effectively filtering strong light and reducing the leaf surface temperature of the middle layer of alum root. At the same time, the transpiration of plants in each layer produces a synergistic effect, significantly improving the air humidity of the planting area, and together creating a cool and humid microclimate suitable for the growth of alum root. The lower layer of gynostemma reduces water evaporation and soil temperature by covering the ground, and cooperates with soil improvement measures to further optimize the rhizosphere environment. This multi-level spatial layout realizes the whole environmental regulation from the ground to the underground, laying a solid physical foundation for the alum root to resist high temperature stress.

[0060] II. Timing synergy of "physical defense" and "biochemical activation" of exogenous substances: At the physiological regulation level, the invention designs a sequential spraying strategy of potassium silicate and rare earth cerium (cerium nitrate), which are complementary in action and form a timing synergy. The first sprayed potassium silicate solution forms a natural silicified protective layer on the leaf surface, playing a "physical barrier" role, which can strengthen the cell wall and reduce water loss, thereby stabilizing the cell structure under high temperature and creating a good foundation for subsequent treatment. The rare earth cerium solution sprayed after several hours focuses on "biochemical activation": it can effectively penetrate into the plant body, enhance the activities of key antioxidant enzymes such as superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT), enhance the ability of root to remove reactive oxygen species, and reduce membrane lipid peroxidation damage (manifested as significant decrease in malondialdehyde MDA content and relative conductivity). At the same time, rare earth cerium can also promote the synthesis of photosynthetic pigments and improve gas exchange parameters (increase net photosynthetic rate Pn and transpiration rate Tr), ensuring energy supply under high temperature. This strategy of first establishing physical defense and then starting biochemical protection achieves a synergistic protection effect from the outside to the inside and layer by layer.

[0061] III. Synergy of ecological and economic benefits: Compared with traditional single shading or chemical treatment, this method has significant comprehensive advantages. In terms of ecological benefits, it avoids the use of high-concentration chemical hormones or potential environmental risk materials, meeting the requirements of green agriculture; the layered planting mode improves the biodiversity and output value (such as economic benefits of passion fruit) per unit of land area. In terms of application benefits, the method has stable and lasting effects, reducing energy consumption and costs of continuous manual intervention through self-regulation of the ecosystem; the rare earth cerium element used is widely available and low-cost, facilitating large-scale application. Ultimately, this method can significantly improve the survival rate of roots under continuous high temperature, effectively expanding their planting range in hot regions such as southern China, and has important industrial application value.

[0062] The above description is only for the preferred embodiments of the present application, and therefore cannot limit the scope of the present application. Any equivalent changes and modifications made in accordance with the scope and content of the present patent should still be within the scope of the present application.

Claims

1. A cultivation method for improving heat tolerance of Alnus nitida, characterized by, Comprising the following steps: Step one. In early March, the bottom layer of the Alum root planting area is cut and grafted Gynostemma pentaphyllum according to the plant spacing of (35-50) cm x (35-50) cm; Each Alum root planting area is equipped with two seedbeds with a length of (4-5) m x a width of (1-2) m, a height of 60-80 cm, and a crown width of 12-18 cm of three-year-old Alum roots placed in the seedbed for cultivation in early March, with a plant spacing of (18-25) cm x (18-25) cm; Passiflora edulis is cultivated in a greenhouse in early March; each Alum root planting area is (4-5) m x (4-5) m; Step two. The Passiflora edulis cultivated in the greenhouse is transplanted to the Alum root planting area in mid-to-late April, with one Passiflora edulis planted in each Alum root planting area, a vine length of 40-60 cm, a shelf support spacing of (4.5-5.5) m x (4.5-5.5) m, a height of 2.3-2.7 m, a top crossbeam made of angle steel, and a mesh with a hole diameter of (8-12) cm x (8-12) cm hung on the crossbeam; Bird's nest ferns are hung on the shelf, with a pot diameter of 18-25 cm, a pot height of 18-25 cm, a crown width of 40-60 cm, and a seedling height of 40-60 cm; the hanging spacing is (1.8-2.2) m x (1.8-2.2) m, with the center of the bird's nest fern plant as the reference; the pot bottom is 1.2-1.5 m away from the ground; Step three. Rare earth cerium solution is sprayed on the Alum roots in summer; the spraying conditions are as follows: after the daily average temperature has been above 30°C for 7 consecutive days, spraying is performed in the morning of the next day; first, 200-400 mg / L potassium silicate solution is uniformly sprayed on the leaves of the Alum roots until the leaves are wet but not dripping, and 50-200 mg / L rare earth cerium solution is sprayed after 3-5 hours.

2. The cultivation method for improving heat tolerance of alnus nitida according to claim 1, wherein: In step one, the bottom layer of the plot in the Alum root planting area is weeded and plowed, 100m 2 Apply 140-160 kg of sheep manure and 250-350 kg of peat soil for base application and improvement, evenly spread on the ground; plow 20-40 cm deep, mix sheep manure, peat soil and plowing layer soil thoroughly; level the soil surface, break up the soil clumps, and prepare for seedling transplanting.

3. The cultivation method for improving heat tolerance of alnus nitida according to claim 1, wherein: During the planting of the Alum roots, water and fertilizer integration planting is adopted, automatic irrigation nozzles are arranged on the top shelf to ensure uniform irrigation from the top layer to the bottom layer, and irrigation is performed twice a day in winter and spring and three times a day in summer and autumn.

4. The cultivation method for improving heat tolerance of alnus nitida according to claim 1, wherein: In step two, the Alum root variety is one or a combination of multiple of "Golden Zebra", "Berry", and "Eternal Purple".

5. The method for cultivating Alnus nepalensis with improved heat tolerance according to claim 1, wherein: In step three, the rare earth cerium solution is a cerium nitrate solution.

6. The method for cultivating Alnus nepalensis with improved heat tolerance according to claim 1, wherein: In step three, the rare earth cerium solution is sprayed on the leaves of the Alum roots.

Images