A method for cultivating and maintaining Acer griseum with color enhancement and color retention

Abstract

The present application relates to the technical field of plant cultivation, in particular to a kind of autumn color leaf garden tree Acer truncatum Bunge color enhancement and color maintenance cultivation method, comprising the following steps: S1.select suitable cultivation environment;S2.leaves protection;S3.leaves discoloration period maintenance.The present application significantly improves the appearance of Acer truncatum Bunge community, especially the skyline viewing effect, the outer layer of tree crown deadwood rate is reduced from the current 17% to 2.8%, the canopy layer has no obvious defect, presents red leaf canopy full, color is more bright, color phase L value increases by 21.3%, the leaf fall rate during viewing period is reduced by 18.6%, the viewing period is extended by 5-8 days, and the bark cracking on the southwest side of the trunk is reduced by 31.7%.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of plant cultivation, in particular to a color enhancement and maintenance method for Acer × freemanii. BACKGROUND

[0002] Acer × freemanii is a deciduous tree of Aceraceae, a famous autumn leaf color tree species. It can grow up to 17 meters high, with a crown diameter of up to 12 meters. It has the advantages of both parent species, Acer rubrum and A. saccharinum. Its leaves are bright red in autumn, the crown is compact, the trunk is straight, and it grows rapidly. It prefers light and has some shade tolerance. It is suitable for slightly acidic soil with good drainage and humid climate, and can be used as a street tree, a courtyard tree, a park landscape tree, and a rural landscape green tree species. It is an important landscape tree species in the autumn in North China, the southern part of Northeast China, and the northern part of East China.

[0003] Acer rubrum and its hybrid varieties are now widely used in gardens around the world. Their greatest ornamental value lies in the vibrant leaf colors they display in autumn, which are composed of chlorophyll, carotenoids, anthocyanins, and betalains. Betalains do not coexist with anthocyanins, but in the detection of pigments in green leaves, semi-red leaves, and red leaves, chlorophyll and carotenoids gradually decompose in autumn, while anthocyanins rapidly accumulate. Therefore, the leaf color of Acer is most closely related to anthocyanins, with cyanidin, delphinidin, and pelargonidin being the main anthocyanins. Anthocyanins form and accumulate anthocyanins in vacuoles by combining with sugar molecules. In natural conditions, anthocyanins exist in the leaves of living Acer plants. Anthocyanins are a type of water-soluble natural pigment that belongs to flavonoids and is divided into anthocyanin derivatives, non-acylated anthocyanin glucosides, and acylated anthocyanin glucosides.

[0004] 1.1 Biological characteristics

[0005] In North America, Acer saccharinum and its relatives Acer rubrum have been expanding their distribution and replacing Quercus rubra as the dominant tree species in forests and parks due to their better adaptation to climate change. In the forest communities surrounding the beaver ponds in Allegany State Park, New York, A. saccharinum and A. rubrum are the dominant species or even the single dominant species. In the study of the color performance of A. saccharinum and A. rubrum in Connecticut, it was found that the precipitation, temperature, drought, and minimum temperature in autumn (from September 1 to October 30) were related to the duration and beauty of the red leaf season, and the degree of high temperature stress in summer (above 35℃) was crucial to ensure the quality of the autumn leaves. In Acer garden trees, whether they are evergreen or autumn color, the expression of bright red color is closely related to the concentration of cyanidin-3-O-glucoside (C3G), and the concentration of C3G decreases from the top to the bottom of the same branch.

[0006] During the leaf coloration process, sucrose, maltose, and lactose are broken down into monosaccharides such as glucose, D-fructose, and L-rhamnose through glycolysis and galactose metabolic pathways. Anthocyanins combine with glucose, rhamnose, galactose, arabinose, and xylose to form anthocyanins, resulting in coloration. After the temperature drops in autumn, the chlorophyll content in the leaf cells of A. saccharinum decreases significantly, while the anthocyanin content increases significantly. The difference in the ratio of anthocyanin to chlorophyll content is closely related to the coloration of autumn leaves.

[0007] 1.2 Ecological characteristics

[0008] The red coloration of A. saccharinum in autumn is a typical phenological performance of deciduous trees. During the aging process of autumn leaves, chlorophyll is the first to degrade, breaking down high-activity substances into substances with no photochemical properties or stable chemical properties. This process can slow down the rapid life activities of plants to some extent. Therefore, timely degradation of chlorophyll not only leads to the phenomenon of leaf discoloration but also has important developmental biology significance. Anthocyanins promote plant reproduction, resist various abiotic and biotic stresses, and scavenge free radicals. Anthocyanins in red leaves can block part of the strong light, reduce the production of oxygen free radicals and superoxide by photosynthesis, and protect the leaves from damage. Anthocyanins also provide a layer of light curtain (Photoprotection) for the photosynthetic system, protect autumn leaves from light damage at low temperatures, extend carbon capture, and help provide the energy and osmotic control required for the phloem to export nutrients from senescent leaves. Therefore, the synthesis of anthocyanins in A. saccharinum autumn leaves is a physiological mechanism that delays aging and helps transport and store nutrients in leaves. The ecological adaptive significance of leaf color change in A. saccharinum is to reduce photosynthetic damage to leaves and facilitate the return of nutrients in old leaves. At the same time, bright leaf color is more beneficial for defense against insect infestation and reduces aphid egg laying.

[0009] 1.3 Autumn color leaf color modulation

[0010] Mineral nutrients can regulate the autumn color leaf color modulation, and nitrogen content can affect the leaf color change. The leaves of Acer griseum with low nitrogen content change color earlier and more completely. During the leaf color transition period of Acer griseum in autumn, the contents of phosphorus and potassium increase significantly, and the nitrogen content decreases, indicating that low nitrogen and high phosphorus and potassium are conducive to the synthesis of anthocyanins and cause the change of leaf color. Therefore, increasing the soluble sugar content in the plant body and reducing the nitrogen content by artificial methods can help improve the ornamental effect of the change of plant leaf color, and branch and trunk girdling and spraying of exogenous soluble sugar can promote the color change of Acer griseum leaves.

[0011] 1.4 Anatomical structure and environmental factors

[0012] The leaf color change process is accompanied by changes in leaf tissue, cell, subcellular structure, and pigment distribution, among which the most significant is the degradation of chloroplasts in autumn leaf color change. The pigments in yellow leaves are mainly distributed in the mesophyll cells of the palisade tissue and spongy tissue, and the pigments in red leaves are only distributed in the vacuoles of the columnar parenchyma cells of the palisade tissue.

[0013] Low temperature, especially night low temperature with large diurnal temperature difference, is conducive to the synthesis of anthocyanins; within a certain range, strong light promotes the accumulation of anthocyanins and enhances the ornamental effect of autumn color leaves; as a protective mechanism, ultraviolet radiation can stimulate the cellular synthesis of anthocyanins. Water and soil conditions also restrict the change of plant leaf color, and moderate drought can improve the purple color of Acer rubrum leaves, slightly acidic soil or neutral moist soil can promote the red color of Acer griseum leaves, and alkaline soil can inhibit the coloration of Acer griseum.

[0014] Although more than 75% of the successfully introduced tree species in China come from North America, the landscape value of Acer griseum still cannot fully reach the level of the original habitat, and the expression of its best ornamental traits is negatively affected by high summer temperature, alkaline soil pH, dry and windy weather in autumn. SUMMARY

[0015] The application provides a method for increasing and prolonging the color of Acer griseum, a garden tree with autumn color leaves, and specifically comprises the following steps: S1. selecting a suitable cultivation environment;

[0016] S11, environment selection, selecting a sandy loam soil waterfront environment with humid and cool climate, deep soil layer, requiring slightly acidic to neutral soil, good drainage in rainy season, no continuous high temperature, drought, ozone and photochemical smog superimposed stress in summer; if the above requirements cannot be met, the pseudo-environment cultivation can be realized by artificial regulation;

[0017] S2. Leaf protection, early spring with 0.4% acetamiprid protective agent for tree trunk whitening, protect the main stem bark, prevent pests; silver red maple sap flow, root irrigation: 0.1% thiamethoxam aqueous solution, 30-40 kg per plant, prevent physiological drought, prevent and control underground and boring pests, before May 1, the second time to add 0.2% transparent (new type of polysiloxane compound) to the white.

[0018] In the first two days of high temperature above 35℃, spray the leaf protection agent with stress relief effect, the first high temperature, leaf spraying 3mmol / L putrescine + 40μmol / L N-acetyl-5-methoxy tryptamine, continuous spraying for 2 days, followed by leaf spraying 15mmol / L amino acid chelated calcium iron magnesium solution.

[0019] The second high temperature, continuous 2 days of leaf spraying 0.5mmol / L salicylic acid, 3.5mmol / L proline and 4.0mmol / L γ-aminobutyric acid, followed by whole tree spraying 0.02mmol / L matrine solution.

[0020] After the high temperature stress in August, continuous 2 days of leaf spraying 100μmol / L 2,4-epibrassinolide, followed by whole tree spraying 0.02mmol / L matrine solution.

[0021] After the average temperature drops to 22℃ for 5 consecutive days, dig a ring-shaped ditch with a width of 25cm and a depth of 15cm inside the vertical projection of the crown edge of each silver red maple, and irrigate it with 10-15L of calcium trolamine (3,5-dioxo-4-propionyl cyclohexane carboxylate) effervescent granules solution with an effective content of 5%, the solution concentration is 150-170mg / L, the granules dosage is 25-35g, and then cover the soil and fill it flat; until the initial stage of discoloration, observe the leaf anatomical structure, the control plant leaf thickness is 163.2μm, the palisade tissue thickness is 57.8μm, the average leaf thickness of the plant treated with calcium trolamine is 205.8μm, and the palisade tissue thickness is 89.1μm. The palisade cells grow and widen, and the palisade tissue obviously thickens, laying the foundation for the accumulation of anthocyanins.

[0022] S3. Leaf discoloration period maintenance;

[0023] S31, when the first night minimum temperature ≤8.2℃ and one day light time ≤12h in autumn, spray the tree leaves with Yefuyuan No.3 microbial agent to improve the nutrient supply of leaves; the water solution concentration is 0.5g / L when the average air humidity is ≥55% on the 5th day, and 12L per tree is sprayed; the water solution concentration is 0.2g / L when the average air humidity is ≤55%, and 30L per tree is sprayed, which is sprayed twice, the air humidity is increased at the same time as the leaf fertilizer is sprayed, and the water deficit stress is reduced, the time is from 17 to 19 o'clock in the afternoon;

[0024] S32, when the 5-day average minimum temperature is ≤6.8℃ and the daily light duration is ≤11.5h, then spray the leaves with Yefuyuan No. 3 microbial agent + an equal amount of brown sugar to supplement the reducing sugar of the leaf cells, which is the raw material for the synthesis and accumulation of anthocyanin; the concentration of the aqueous solution is 1.0g / L when the 5-day average air humidity is ≥55%, and 12L of the solution is sprayed on each tree; the concentration of the aqueous solution is 0.5g / L when the 5-day average air humidity is ≤55%, and 30L of the solution is sprayed on each tree in two times, at 16-18pm.

[0025] In a possible implementation, the step S1 further comprises S12, community planting, planting two specifications of tall trees and trees with large diameters at a distance of 5-7m from the southwest side of Acer grandidentatum Batal. to provide lateral shading in the autumn leaf fall period, and the number of the trees is less than half of the number of Acer grandidentatum Batal.

[0026] In a possible implementation, the step S1 further comprises S13, optimization of soil physical and chemical properties, and the soil at the base of the tree trunk is mixed with grass peat, humus soil under pine-oak forest and original soil at a ratio of 1:1:1 within a range of 15 times of the base diameter, and the thickness is ≥20cm.

[0027] In a possible implementation, when the original soil is hard, river sand is mixed at a volume ratio of grass peat: humus soil under pine-oak forest: original soil: river sand = 1:1:0.5:0.5, and the thickness is 30cm.

[0028] In a possible implementation, for alkaline soil, the pH value is controlled and improved first, if the pH value of the soil is ≥7.4≤8.0, then ferrous sulfate is applied in a ring-shaped shallow ditch at 10 times of the base diameter, the dosage is pH×55+D×18(g); if the pH value of the soil is ≥8.0, then ferrous sulfate is applied in a ring-shaped shallow ditch at 8 times of the base diameter, the dosage is pH×36+D×9(g), and sulfur powder is applied in a ring-shaped shallow ditch at 10 times of the base diameter at the same time, the dosage is pH×52+D×16(g), wherein pH is the measured value of the soil pH value, and D is the base diameter of Acer grandidentatum Batal. measured in centimeters.

[0029] In a possible implementation, the step S3 further comprises S33, during the mottled leaf color period, a compound solution of 1mmol / L calcium fulvate, 1mol / L spermidine and 0.1μmol / L 1-methylcyclopropene is sprayed to delay the aging of the leaves and the formation and development of the leaf abscission layer.

[0030] S34, during the red peak period to the end of the red leaves, 3mmol / L potassium fulvate and 1μmol / L trans-zeatin (6-trans-4-hydroxy-3-methyl-but-2-enylaminopurine) are sprayed on the leaves to prevent leaf fall.

[0031] In one possible implementation method, before the onset of high-temperature stress, apply 5 kg of diluted vanadium fertilizer solution to the roots every two weeks, diluted 20 times, for a total of 6 applications. The fermentation formula for the vanadium fertilizer solution is ferrous sulfate: horse paw flakes: sesame paste residue: water = 5.2:1.6:9:200. The solution is placed in a large vat, covered with a black plastic film, and fermented under full light for 40 days. Two days before fertilization, add 2 kg of potassium sulfate and stir well.

[0032] In one possible implementation method, the autumn maintenance measures for the silver maple are strictly carried out according to the low temperature and photoperiod product model:

[0033] In the formula, R sen S represents the daily leaf senescence rate. sen This refers to the leaf senescence state, specifically from the date D onwards when leaf senescence begins. start R until a certain date sen The summation of S; sen The critical value S is reached on day Y. * sen At that time, autumn phenological phenomena occur; T i P represents the daily minimum temperature on day i. i Represents the number of hours of the optical cycle on day i, where

[0034]

[0035] The above-mentioned one or more technical solutions in the embodiments of the present invention have at least one of the following technical effects: The present invention significantly improves the appearance of the silver maple community, especially the viewing effect of the skyline, reduces the rate of dead shoots in the outer layer of the canopy from the current 17% to 2.8%, the canopy layer has no obvious defects, presents a full red leaf canopy, the color is brighter, the hue L value is increased by 21.3%, the leaf drop rate during the viewing period is reduced by 18.6%, the viewing period is extended by 5-8 days, and the bark cracking on the southwest side of the trunk is reduced by 31.7%.

[0036] The leaves of the silver maple are well maintained in the early part of the annual growing season. The rate of lesions and bites caused by biological hazards does not exceed 3%, and the rate of physiological diseases such as leaf scorch caused by abiotic stress is less than 7%. Before the autumn viewing period, 90% of the leaves are in a healthy state, and the maximum photometric efficiency Fv / FM is ≥0.8. Attached Figure Description

[0037] Figure 1 This is the autumn landscape effect of the red leaves of the silver maple community at the end of the season, achieved through scientific cultivation and maintenance.

[0038] Figure 2 It is a community landscape of silver maple in the initial stage of color change under scientific cultivation and protection.

[0039] Figure 3 is the peak red leaf community landscape of Acer truncatum under scientific cultivation and conservation.

[0040] Figure 4 is the tree crown state of Acer truncatum at the end of red leaf period under scientific cultivation and conservation.

[0041] Figure 5 is the tree crown state of Acer truncatum at the end of red leaf period under ordinary cultivation and conservation.

[0042] Figure 6 is the healthy leaf of Acer truncatum at the vigorous growth period.

[0043] Figure 7 is the tree crown state of Acer truncatum at the peak red leaf period under ordinary cultivation and conservation.

[0044] Figure 8 is the peak red leaf community landscape of Acer truncatum under ordinary cultivation and conservation. DETAILED DESCRIPTION

[0045] In order to make the above objectives, characteristics and advantages of the present application more apparent and easy to understand, the specific embodiments of the present application are described in detail below in conjunction with the drawings. In the following description, a large number of specific details are set forth in order to fully understand the present application. However, the present application can be implemented in many other ways different from those described below, and those skilled in the art can make similar improvements without departing from the concept of the present application, so the present application is not limited by the specific embodiments disclosed below.

[0046] A color-enhancing and color-keeping cultivation and conservation method for Acer truncatum, a garden tree with autumn color leaves, specifically includes the following steps:

[0047] S1. Selecting a suitable cultivation environment

[0048] S11. In the warm temperate southern region of Northeast China, the semi-humid region with more than 500 mm of rainfall in North China, the cool and humid region of hilly and mountainous areas in Central China, the sandy loam soil site with deep soil layer, near the pond or stream, requiring slightly acidic to neutral soil, good drainage in the rainy season, no continuous high temperature and drought in summer, no serious physiological drought in winter and spring; if the above requirements cannot be met, the pseudo-environment cultivation can be achieved through artificial regulation.

[0049] S12. Garden landscape plant community planting method, select the same autumn color leaf landscape tree species such as Ginkgo biloba, Fraxinus, Catalpa, Tilia, etc. Early deciduous tree species, do not assist tree species, do not crown large shade, should be planted in the southwest to northwest side of Acer truncatum, which can block part of the sunlight during high temperature period, reduce wind speed during dry period, and reduce the diurnal temperature difference of tree trunk to reduce bark cracking.

[0050] S13. Soil physical and chemical properties are optimized, and the soil in the main area of capillary root distribution is made weakly acidic to neutral and well ventilated by soil conditioner, with a bulk density of ≤1.2 g / cm 3 The content of organic matter is more than 2.0%. The herbaceous ground cover plants are used to protect the ground surface and regulate the temperature and humidity of the surface soil. The ornamental herbaceous cover plants such as purpleleaf wintergreen, white clover, Chinese smilax, alfalfa, bluegrass, Japanese leatleaf, and top flower bench fruit can be planted under the Acer truncatum var. rubrum forest.

[0051] S2. Leaf protection in the growing season

[0052] S21. Cultivating tree vigor, early spring, using a protective agent containing 0.4% nitenpyram for tree trunk whitening to protect the main trunk bark and prevent pests; when the Acer truncatum var. rubrum sap starts to flow, root irrigation is carried out: 30-40 kg of 0.1% thiamethoxam aqueous solution per plant to prevent physiological drought and control underground and boring pests; the tree trunk bark cracking rate is reduced from 17.3% to less than 2.6%, and the boring pest incidence is reduced from 28.6% to 1.3%; before May 1, the second whitening is added with 0.2% trans-copper (a new type of polysiloxane compound), and the dieback disease index is investigated, which is reduced from 29.1 to 13.7 compared with the control.

[0053] Disease index calculation method: disease index = 100 x [Σ (number of plants at each level x corresponding level representative value)] / (total number of plants surveyed x highest level representative value of disease); wherein the disease classification representative value is shown in Table 1.

[0054] Table 1: Acer truncatum var. rubrum physiological disease classification table

[0055] Disease rating Incidence Representative value Ⅰ No disease 0 Ⅱ Number of diseased shoots < 1 / 4 1 Ⅲ 1 / 4 < number of diseased shoots < 1 / 2 2 Ⅳ 1 / 2 < number of diseased shoots < 3 / 4 3 Ⅴ Disease incidence ≥ 3 / 4 of the shoots 4

[0056] S22. Relieve high temperature stress in North China and south of it, from late June to mid-August, it is easy to have high temperature weather above 35℃, causing high temperature stress, even superimposed with drought and ozone, causing leaf damage of Acer truncatum var. rubrum, showing leaf margin chlorosis, leaf surface appearing scorching spots, and scorching spots continuously appearing as scorched leaves, through the use of special vanadium fertilizer water of the application, to improve the stress resistance of Acer truncatum var. rubrum, wherein the fermentation process of the vanadium fertilizer water is: ferrous sulfate, horseshoe pieces, sesame cake residue and water are placed in a large jar in the ratio of 5.2:1.6:9:200, covered with black plastic film, placed in full light for 40 days, 2 kg of potassium sulfate is added two days before fertilization, and stirred uniformly.

[0057] S23. In late June, according to the weather forecast, spray the leaf protection agent with stress relief effect two days before the occurrence of high temperature above 35℃, before the first occurrence of high temperature above 35℃, spray 3mmol / L putrescine + 40μmol / L N-acetyl-5-methoxytryptamine (melatonin) on the leaves, continuously spray for 2 days, then spray 15mmol / L calcium, iron and magnesium amino acid chelate solution on the leaves.

[0058] S24. The second high temperature, i.e. the second occurrence of weather above 35℃, continuously spray 0.5mmol / L salicylic acid, 3.5mmol / L proline and 4.0mmol / L γ-aminobutyric acid on the leaves, then spray 0.02mmol / L matrine solution on the whole tree.

[0059] S25. High temperature stress occurring after August, continuously spray 100μmol / L 2,4-epibrassinolide on the leaves for 2 days, then spray 0.02mmol / L matrine solution on the whole tree.

[0060] S26. After the average temperature continuously drops to 22℃ for 5 days, dig a ring-shaped ditch with a width of 25cm and a depth of 15cm inside the vertical projection of the crown of each tree, irrigate each tree with 10-15L of water solution of calcium trolamine effervescent granules with an effective content of 5%, the solution concentration is 150-170mg / L, the granule dosage is 25-35g, then cover the soil and fill it flat, until the initial observation of leaf dissection structure, the leaf thickness of the control plant is 163.2μm, the palisade tissue thickness is 57.8μm, the average leaf thickness of the plant treated with calcium trolamine is 205.8μm, the palisade tissue thickness is 89.1μm; the palisade cells grow and widen, the palisade tissue is obviously thickened, which lays a foundation for the accumulation of anthocyanins.

[0061] S3. Leaf color change period maintenance

[0062] S31. When the first occurrence of night minimum temperature ≤8.2℃ and one-day light duration ≤12h in autumn, spray the leaves with Yefuyuan No.3 microbial agent to improve the nutrient supply of the leaves; the water solution concentration is 0.5g / L when the average air humidity is ≥55% on the 5th day, 12L per tree; the water solution concentration is 0.2g / L when the average air humidity is ≤55%, 30L per tree, sprayed twice, increase the air humidity and reduce water deficit stress at the same time of spraying the leaf fertilizer, the time is from 17:00 to 19:00.

[0063] S32. When the 5-day average minimum temperature is ≤ 6.8℃ and the daily light duration is ≤ 11.5h, spray the leaves with Ye Fuyuan No. 3 microbial agent + an equal amount of brown sugar to supplement the reducing sugar for anthocyanin synthesis and accumulation of raw materials; the water solution concentration is 1.0g / L when the 5-day average air humidity is ≥ 55%, and 12L is sprayed per tree; the water solution concentration is 0.5g / L when the 5-day average air humidity is ≤ 55%, and 30L is sprayed per tree in two times, at 16-18pm.

[0064] S33. During the mottled leaf color period, spray 1mmol / L of calcium fulvic acid, 1mol / L of spermidine and 0.1μmol / L of 1-methylcyclopropene complex solution to delay leaf senescence and delay the formation and development of leaf abscission layer.

[0065] S34. From the red peak period to the end of red leaves, spray 3mmol / L of potassium fulvic acid and 1μmol / L of trans-zeatin (6-trans-4-hydroxy-3-methyl-but-2-enyl aminopurine) on the leaves to prevent leaf abscission and extend the ornamental period by 4-8 days.

[0066] S35. Randomly select 50 test plants and 50 control plants, select moderate branches, and record the color and morphology data of 30 leaves (leaf scars), and calculate according to the beauty degree evaluation regression model:

[0067] SBE = 6.871*H + 6.650*S + 4.282*B + 4.121*C - 4.991*D - 32.49

[0068] Wherein, H is hue, S is saturation, B is brightness, C is colorful leaves, and D is fallen leaves

[0069] The average beauty degree of a single plant of scientifically cultivated and maintained Acer griseum is 91.67, and that of the control is 38.16.

[0070] Table 2: Beauty degree related factor survey table of Acer griseum

[0071]

[0072] In addition, select standard branches in the crown and select moderate leaves for determination:

[0073] ① Use a color difference meter to measure the color difference value of the leaves, mainly record the a value.

[0074] ② Measure chlorophyll, anthocyanin and carotenoid, and calculate the ratio of anthocyanin to chlorophyll.

[0075] The content of chlorophyll and carotenoid in leaves was detected by spectrophotometer method: 30 pieces of leaf round pieces with a diameter of 5 mm were taken by puncher, mixed and weighed 0.2 g, then ground into homogenate with quartz sand and 80% acetone, and made up to 10 mL in a volumetric flask, and placed in the dark for 48 h, and fully extracted until the green color of the leaves disappeared. The supernatant was extracted, and 80% acetone solution was used as blank control. The absorbance was measured at 664 nm, 647 nm and 470 nm, respectively. The pigment content was calculated according to the following formula (Porra R J, Thompson WA, Kriedemann P E. Determination of accurate extinction coefficients and simultaneous equations for assaying chlorophyllsa and b extracted with four different solvents. Biochim biophys acta, 1989, 975: 384-394):

[0076] Chlorophyll a concentration = 9.78 x A 664 -0.99 x A 647

[0077] Chlorophyll b concentration = 22.39 x A 647 -5.42 x A 664

[0078] Carotenoid concentration = (1000 x A 470 -3.23 x chlorophyll a concentration - 104 x chlorophyll b concentration) / 229

[0079] Content formula = (c x v x n) / 1000 x m

[0080] In the formula, c: pigment concentration; v: volume of measured liquid (mL); n: dilution multiple; m: mass (g).

[0081] The anthocyanin content was determined by spectrophotometer method: leaf round pieces with a diameter of 5 mm were punched, mixed and weighed 0.2 g, and then cut into pieces and extracted with 20 mL of 0.1% (by volume) hydrochloric acid methanol solution in the dark for 24 h. The extraction process was stirred and shaken at regular intervals. After 24 h, the supernatant was obtained by centrifugation at 1000 r·min -1 for 10 min at room temperature, and the D530 and D650 values were measured by spectrophotometer. The anthocyanin content calculation formula is:

[0082] Anthocyanin content (mg / g FW) = (D 530 -0.25 x D 650) x volume of extraction liquid / 0.0462 / fresh leaf mass

[0083] The soluble sugar content of the leaf blade is determined by anthrone colorimetry: 0.2 g of fresh leaves is weighed and added into 20 mL of distilled water in a test tube, and then boiled in a water bath for 30 minutes, centrifuged at 3000 r / min for 10 minutes, and the operation is repeated twice, and the supernatant of the two times of extraction is combined and diluted to 50 mL. 10 mL of the supernatant is diluted to 100 mL, and 3 test tubes are taken, and 1 mL of the sample stock solution and 5 mL of anthrone reagent are added into the test tubes, respectively; another test tube is taken, and the same amount of distilled water is added into the test tube instead of the extraction liquid and the anthrone reagent, and then mixed, which is used as a control. The test tubes are fully shaken, and then placed in a water bath at 100 ℃ for 10 minutes, and then the absorbance value at 630 nm is measured after cooling, and then the soluble sugar content is calculated.

[0084] The chlorophyll fluorescence parameters are determined by using a HANDYPEA plant efficiency analyzer to determine the health state of the leaf blade of Acer truncatum Batal., and Fv / Fm≥0.8 is a normal health state.

[0085] According to the above four groups of data, the coloring process of the autumn leaf blade of Acer truncatum Batal. is divided into: a discoloration initial stage, at which the leaf blade starts to present a light red color; a mottled leaf color stage, at which the leaf blade surface presents a red and green mottled color, and 20-30 % of the leaf blade presents a color; a red color peak stage, at which 50-60 % of the leaf blade turns red; a red leaf final stage, at which almost all of the leaf blade is bright and deep red; and a red leaf falling stage, at which more than 30 % of the leaf blade falls off.

[0086] The SPAD chlorophyll relative value is measured by using a handheld chlorophyll meter (SPAD-502, KONICA MINOLTA): the discoloration initial stage is 28-32; the mottled leaf color stage is 25-27; the red color peak stage is 21-23.5; the red leaf final stage is 18-20; and the red leaf falling stage is 7-13. The chlorophyll content of the leaf blade of Acer truncatum Batal. in the coloring period of the autumn leaf blade presents a downward trend, and the chlorophyll content is relatively slow in the red leaf final stage (19-21) and the red leaf falling stage (9-13) by using the application, so that the leaf blade maintains a longer time of vitality and prolongs the viewing period.

[0087] L*, a*, b* values of the fruit peel chroma were measured by using a CR-400 portable colorimeter, and chroma (C*) and hue angle (h°) values were calculated. In the color index of Acer truncatum Bunge autumn leaves, L* value represents the brightness of the leaves, with a value range of 0-100, and the larger the L* value, the brighter the leaves. The a* value represents the red-green color difference of the leaves, and the process of a* value changing from -a* to +a* represents the fading of green and the enhancement of red. The larger the a* value, the deeper the red color, and the smaller the a* value, the deeper the green color. The b* value represents the yellow-blue color difference of the leaves, and the process of b* value changing from -b* to +b* represents the fading of blue and the enhancement of yellow. The larger the b* value, the deeper the yellow color, and the smaller the b* value, the deeper the blue color. The larger the chroma C* value, the purer the color. The h° value represents the hue of the leaves.

[0088] The a* value of Acer truncatum Bunge measured by the colorimeter at the initial stage of color change is -5-10, 11-25 at the mottled leaf color stage, 26-35 at the red color peak stage, 36-40 at the end of red leaf stage, and 20-40 at the red leaf falling stage. At this time, the leaves become dull, and the corresponding L* value decreases to 0-9.

[0089] The fresh leaf chlorophyll content of Acer truncatum Bunge at the initial stage of color change is 1.91-2.28 (mg / g FW), 1.63-1.86 (mg / g FW) at the mottled leaf color stage, rapidly decreases to 1.17-1.49 (mg / g FW) at the red color peak stage, 0.52-0.82 (mg / g FW) at the end of red leaf stage, and very little 0-0.45 (mg / g FW) at the red leaf falling stage. The above unit is the number of milligrams of chlorophyll contained in 1 gram of fresh leaves. By using the maintenance technology of the present application, the chlorophyll content of Acer truncatum Bunge leaves decreases slowly at the end of red leaf stage (0.73-0.82 mg / g FW) and at the red leaf falling stage (0.38-0.45 mg / g FW), maintaining a longer time of leaf photosynthetic activity.

[0090] The anthocyanin content of Acer truncatum Bunge at the initial stage of color change is 0.61 (mg / g FW), 0.92-1.82 (mg / g FW) at the mottled leaf color stage, the anthocyanin content increases to 2.17-5.09 (mg / g FW) at the red color peak stage, reaches a peak of 8.69-14.28 (mg / g FW) at the end of red leaf stage, and slightly decreases to 13.27-14.06 (mg / g FW) at the red leaf falling stage. The above unit is the number of milligrams of anthocyanin contained in 1 gram of fresh leaves. The red color of Acer truncatum Bunge autumn leaves has a significant positive correlation with the anthocyanin content of the leaf cells. The scientific maintenance technology of the present application can significantly improve the anthocyanin content at the mottled leaf color stage, and prolong the duration of the red color peak stage by 2-3 days.

[0091] The carotenoid content of fresh leaves in the initial discoloration period is 0.34-0.38 (mg / g FW), the mottled leaf color period is 0.31-0.35 (mg / g FW), the red peak period is 0.23-0.28 (mg / g FW), the red leaf end period is 0.16-0.19 (mg / g FW), and the red leaf litter period is 0.06-0.13 (mg / g FW). The above unit is milligrams of carotenoids contained in 1 gram of fresh leaves. After the implementation of the maintenance technology of the present application, the carotenoid content in the autumn leaves decreases slowly, but the total number is relatively small, and the carotenoid has little to do with the color of the autumn leaves of Acer pseudosieboldianus.

[0092] The soluble sugar content of fresh leaves in the initial discoloration period is 0.3-0.5 (mg / g FW), the mottled leaf color period is 0.6-0.8 (mg / g FW), the red peak period is 0.9-1.3 (mg / g FW), the red leaf end period is 1.4-2.0 (mg / g FW), and the red leaf litter period is 1.1-1.6 (mg / g FW). The above unit is milligrams of soluble sugar contained in 1 gram of fresh leaves. The change of the content of soluble sugar shows a rhythm consistent with the change of the color of the autumn leaves of Acer pseudosieboldianus. When the holding temperature is lower than 6.8℃ and the photoperiod is less than 11.5h, the application of red sugar promotes the synthesis of soluble sugar in leaf cells to anthocyanins, and to a certain extent, increases the content of anthocyanins and a* value.

[0093] The anthocyanin mass / chlorophyll mass in the initial discoloration period is 0.05-0.09, the mottled leaf color period is 0.14-0.78, the red peak period is 1.66-5.52, the red leaf end period is 6.82-22.58, and the red leaf litter period is 21.39-28.92.

[0094] The embodiments of the specific implementation are the preferred embodiments of the present application, not limited to the protection scope of the present application, so: any equivalent changes made according to the structure, shape, principle of the present application should be covered within the protection scope of the present application.

Claims

1. A kind of autumn color leaf garden tree Acer griseum color enhancement and color retention cultivation and maintenance method, it is characterized by: Specifically comprising the following steps: S1. Selecting a suitable cultivation environment; S11, environment selection, selecting a sandy loam soil by the waterfront environment with humid and cool climate, requiring slightly acidic to neutral soil, good drainage in the rainy season, no continuous high temperature, drought, ozone and photochemical smog superimposed stress in summer; if not meet the above requirements, then through artificial regulation to achieve the quasi-natural cultivation; S2. Leaf protection, two days before the occurrence of high temperature weather above 35℃, spraying leaf protection agent with stress relief effect, the first high temperature, leaf spraying 3mmol / L putrescine + 40μmol / L N-acetyl-5-methoxy tryptamine, continuous spraying for 2 days, then spraying 15mmol / L calcium iron magnesium amino acid chelate solution on the leaves; The second high temperature, continuous 2 days of spraying 0.5mmol / L salicylic acid, 3.5mmol / L proline and 4.0mmol / L gamma-aminobutyric acid on the leaves, then spraying 0.02mmol / L matrine solution on the whole tree; After the occurrence of high temperature stress in August, spraying 100μmol / L 2,4-epibrassinolide on the leaves for 2 days, then spraying 0.02mmol / L matrine solution on the whole tree; After the average temperature drops to 22℃ for 5 consecutive days, dig a ring ditch with a width of 25cm and a depth of 15cm inside the vertical projection of the tree crown, irrigate each Acer truncatum with 10-15L of calcium (3,5-dioxo-4-propionylcyclohexanecarboxylic acid) effervescent granules solution with effective content of 5%, the solution concentration is 150-170mg / L, the granules dosage is 25-35g, then cover the soil and fill it flat; S3. Leaf discoloration period maintenance.

2. The color enhancement and color retention method for Acer griseum Batal. according to claim 1, characterized in that: The step S1 also includes S12, community planting, planting two specifications of tall trees and large diameter trees with early autumn leaf fall period in the southwest side of Acer truncatum 5-7 meters away to provide lateral shade, the number of which is less than half of the number of Acer truncatum.

3. The method for cultivating and maintaining Acer grandidentatum Hanel in autumn color according to claim 1, characterized in that: The step S1 also includes S13, soil physical and chemical property optimization, the soil at the base of the tree trunk within 15 times of the base diameter is mixed with grass charcoal soil, pine and oak forest humus soil and original soil in the ratio of 1:1:1, with a thickness of ≥20cm.

4. The color enhancement and color retention method for Acer griseum according to claim 3, characterized in that: When the original soil is hard, then mix with river sand, the volume ratio of grass charcoal soil: pine and oak forest humus soil: original soil: river sand is 1:1:0.5:0.5, with a thickness of 30cm.

5. The color enhancement and color retention method for Acer griseum according to claim 3, wherein the method further comprises the step of: For alkaline soil, acid-base regulation and improvement should be carried out first, if the soil pH value is ≥7.4≤8.0, then at 10 times of the base diameter, open ring-shaped shallow ditch and apply ferrous sulfate, the dosage is pH×55+D×18(g); if the soil pH is ≥8.0, then at 8 times of the base diameter, open ring-shaped shallow ditch and apply ferrous sulfate, the dosage is pH×36+D×9(g), at the same time, at 10 times of the base diameter, open ring-shaped shallow ditch and apply sulfur powder, the dosage is pH×52+D×16(g), where pH is the measured soil pH value, D is the base diameter of Acer truncatum in centimeters. ​ 6. The method for cultivating and maintaining the autumn-colored maple (Acer spp.) to enhance and prolong its color in gardens, as described in claim 1, is characterized in that: The step S3 comprises S31, when the first night minimum temperature in autumn is ≤8.2℃ and the light time in a day is ≤12h, then the tree leaves are sprayed with Ye Fuyuan No.3 microbial agent to improve the nutrient supply of the leaves; the water solution concentration is 0.5g / L when the average air humidity in 5 days is ≥55%, and 12L is sprayed to each tree; the water solution concentration is 0.2g / L when the average air humidity in 5 days is ≤55%, and 30L is sprayed to each tree in two times, the air humidity is increased at the same time of spraying the leaf fertilizer, the water deficit stress is reduced, and the time is from 17 to 19 o'clock in the afternoon; S32, when the average minimum temperature in 5 days is ≤6.8℃ and the light time in a day is ≤11.5h, then the tree leaves are sprayed with Ye Fuyuan No.3 microbial agent + equal amount of brown sugar to supply the reducing sugar for anthocyanin synthesis; the water solution concentration is 1.0g / L when the average air humidity in 5 days is ≥55%, and 12L is sprayed to each tree; the water solution concentration is 0.5g / L when the average air humidity in 5 days is ≤55%, and 30L is sprayed to each tree in two times, and the time is from 16 to 18 o'clock in the afternoon.

7. The color enhancement and color retention method for Acer griseum according to claim 6, wherein the method further comprises the step of: The step S3 further comprises S33, during the mottled leaf color period, 1mmol / L of calcium fulvic acid, 1mol / L of spermidine and 0.1μmol / L of 1-methylcyclopropene are sprayed to delay the leaf senescence and the formation and development of the leaf petiole abscission layer; ​ S34, from the red peak period to the end of the red leaves, 3mmol / L of potassium fulvic acid and 1μmol / L of trans-zeatin (6-trans-4-hydroxy-3-methyl-but-2-enylaminopurine) are sprayed to prevent the leaf fall.

8. The method for cultivating and maintaining the autumn-colored maple (Acer rubrum) to enhance and prolong its color according to claim 1, characterized in that: Before the high temperature stress appears, the vanadium fertilizer water diluted by 20 times is used to fertilize the roots every 2 weeks, 5kg of thin liquid fertilizer is used each time, and the fertilization is performed 6 times; the fermentation and retting formula of the vanadium fertilizer water is ferrous sulfate: hoof piece: sesame cake residue: water = 5.2: 1.6: 9: 200, which is placed in a large jar, covered with black plastic film, and placed in full light for retting for 40 days, 2kg of potassium sulfate is added two days before the fertilization, and stirred uniformly.

9. The method for cultivating and maintaining the autumn-colored maple (Acer spp.) to enhance and prolong its color in gardens, as described in claim 1, is characterized in that: The implementation of the autumn maintenance measures of the silver-red maple is strictly in accordance with the low temperature and photoperiod product model: where R sen is the daily leaf senescence rate; S sen is the leaf senescence status, i.e. the sum of R start from the leaf senescence start date D sen to a certain date; when S sen reaches a critical value S * sen on day Y, the autumnal phenology occurs; T i denotes the daily minimum temperature on day i, P i denotes the photoperiod hours on day i; wherein,

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