A maple good seed breeding method based on maple leaf color evaluation

Abstract

The application discloses a maple good variety breeding method based on leaf color evaluation of colorful maple, which is to collect maple seeds of different families to breed seedlings and use the seedlings to build test forests, after the test forests are built, the test forests are determined in December every year when the maple leaves change color in the peak period; the determined indexes include leaf color indexes and growth indexes; the leaf color indexes include leaf color system, single plant color changing amount and leaf CIE-Lab color space parameters; the growth indexes include preservation rate and leaf health degree; the maple family varieties reaching the various indexes are selected as the final selected excellent color changing family, and then the maple forest is cultivated and built according to the seed propagation, seedling cultivation, afforestation land preparation, afforestation, tending, topdressing and forest land management and the like in the built test forests. The application can not only breed the excellent color changing family of maple, but also has the advantages of being convenient, effective and suitable for popularization and application.

Description

Technical Field

[0001] The invention belongs to the technical field of liquidambar breeding, and particularly relates to a liquidambar improved variety breeding method based on leaf color evaluation of colorful liquidambar. Background Art

[0002] Liquidambar formosana Liquidambar formosana Hance is a species of Liquidambar formosana of the Hamamelidaceae family ( Liquidambar Liquidambar formosana is a widely distributed deciduous tree. It is highly adaptable, resistant to wind and fire, and naturally regenerates easily. It thrives in red and yellow soils, earning it a reputation as a pioneer tree for barren and rocky mountains. In autumn, its leaves gradually change from green to red, purple, and orange-yellow, earning it the nickname "maple leaves redder than February flowers." It is highly ornamental and a prime forest landscape species, playing a vital role in cultivating colorful forests, effectively enhancing their landscape and tourism value, and promoting the development of forest tourism. Through scientific breeding, superior Liquidambar strains have been selected, demonstrating not only strong adaptability and healthy growth, but also vibrant, ornamental foliage, maximizing its ornamental value. When breeding varieties with good color-changing effects, it is necessary to study and evaluate the genetic variations among Liquidambar families, and use full-length transcriptome sequencing technology to gain an in-depth understanding of the genetic basis of the color-changing period of Liquidambar leaves, obtain the genetic factors that affect leaf color change, and then use them as a basis for breeding improved varieties. However, the research on the genetic factors of leaf color change is difficult, and there are many varieties of Liquidambar, so the research workload is large. It is still necessary to study convenient and effective methods for breeding improved Liquidambar varieties that are suitable for promotion and application. Summary of the Invention

[0003] In response to the above shortcomings, the present invention discloses a method for breeding improved varieties of Liquidambar formosana based on leaf color evaluation of colored Liquidambar formosana, which can not only breed excellent color-changing families of Liquidambar formosana, but also has the advantages of being convenient, effective and suitable for promotion and application.

[0004] The present invention is achieved by adopting the following technical solutions:

[0005] A method for breeding improved varieties of Liquidambar formosana based on leaf color evaluation of colored liquidambar formosana comprises the following steps:

[0006] S1. Collect seeds of Liquidambar formosana from different families and propagate them to obtain seedlings with a height greater than 40 cm;

[0007] S2. Using the seedlings described in step S1 to establish a test forest, which specifically includes the following:

[0008] The afforestation test is divided into three or more test points; in the test points, 15 plants of each family are planted, and 5 plants are planted in a single row as a small area; the afforestation density is 110 plants per mu, and the plant row spacing is 2 m x 3 m; the afforestation is planted in the current year from January to April, the specification of the planting hole is that the hole surface is 60 cm wide, the hole bottom is 40 cm wide, and the hole depth is 40 cm, 500 g of compound fertilizer is placed in each planting hole before planting; the survival rate is investigated one month after afforestation, and re-planting is carried out; pesticide spraying is carried out every April to prevent and control diseases and pests, and compound fertilizer is applied at a ratio of 500 g per plant every year from May to June, and the soil is loosened and weeded once every year from July to August;

[0009] S3, after the test forest is built, the test forest is measured in the period when the leaves of the test forest change color, that is, when more than 70% of the leaves of the plant are completely changed, more than 80% of the total plants are changed;

[0010] The measured indexes include leaf color indexes and growth indexes; the leaf color indexes include leaf color systems, single-plant color change amounts, and leaf CIE-Lab color space parameters (brightness L, red-green attribute a, and yellow-blue attribute b);

[0011] The leaf color systems are divided into red, yellow, orange, and green, which are determined by color comparison cards and visual observation of the leaf color of each plantamur, if the color systems of at least 3 plants in each small area of a family are consistent for 3 consecutive years, the amur variety of the family is marked as a qualified variety, and all qualified varieties form a set A1;

[0012] The single-plant color change amount is the percentage of the number of changed leaves of each plant to the total number of leaves, if the single-plant color change amount of at least 3 plants in each small area of a family is greater than or equal to 70%, the amur variety of the family is marked as a qualified variety, and all qualified varieties form a set A2;

[0013] The leaf CIE-Lab color space parameters are selected from plants with a single-plant color change amount greater than or equal to 70% in each small area, 3 to 6 leaves are collected, then 3 leaves are randomly selected and wiped to remove surface dust, and a color difference instrument is used to measure the leaf color parameters, the measurement is performed under D65 light source and angle 10°, a 8 mm diameter window is used to measure the color of the front of the leaf, 10 positions of each leaf are measured and the average value is calculated; the leaf color parameters include brightness L value (the larger the L value, the brighter the leaf color), red-green attribute a value (the larger the a value, the more the leaf color is biased towards red), and yellow-blue attribute b value (the larger the b value, the more the leaf color is biased towards yellow);

[0014] With positive green and positive red as the standard, the lightness L value, red-green attribute a value and yellow-blue attribute b value of the leaf color parameter are converted into standardized scores, the positive green is assigned as 0 points and the positive red is assigned as 100 points, the color difference ΔE0 between the two is calculated according to the color difference calculation formula, the L i , a i , b i value of the collected leaf and the L 红 , a 红 , b 红 value of the positive red are calculated, the color difference ΔE1 is calculated, and finally the color standardization score S of the collected leaf is calculated by calculating the ratio of ΔE1 and ΔE0, wherein L 红 =41.07, a 红 =37.84, b 红 =24.17 and L 绿 =28.69, a 绿 =1.47, b 绿 =-1.55, and the specific calculation formula is as follows:

[0015] Δ E 0=[(Δ L ) 2 +(Δ a ) 2 +(Δ b ) 2 ] 0.5 ; Δ L = L 红 - L 绿 ; Δ a = a 红 - a 绿 ; Δ b = b 红 - b 绿 ;

[0016] ΔE1= [(Δ L i ) 2 +(Δ a i ) 2 +(Δ b i ) 2 ] 0.5 ; Δ L i = L 红 - L i ; Δ ai = a 红 - a i ;Δ b i = b 红 - b i ;

[0017] S =100-(ΔE1 / Δ E 0) ×100;

[0018] If the color selection standardization score S of at least 3 plants in each plot of each test site of a family is greater than or equal to 60 within 3 years, the family is taken as the independent variable, and the score is taken as the dependent variable to perform nested design variance analysis with year, test site, plot, and single plant as the independent variables. If the year, test site, plot, and single plant have no significant effect on the score, the maple variety of the family is marked as a standard variety, and all the standard varieties are combined to form a set B1.

[0019] The growth index includes the survival rate and the leaf health degree.

[0020] The survival rate is the number of surviving plants in each plot of 5 single plants. If the survival rate of a family in each plot is greater than or equal to 3, the maple variety of the family is marked as a standard variety, and all the standard varieties are combined to form a set A3.

[0021] The leaf health degree is obtained by scanning the collected leaves with a scanner, then importing the scanned pictures into a plant image analyzer to count the areas of disease spots, insect damage, and wilting, and calculating the percentage of the total area of the disease spots, insect damage, and wilting in the total leaf area. If the leaf health degree of at least 3 plants in each plot of a family is less than or equal to 10%, the maple variety of the family is marked as a standard variety, and all the standard varieties are combined to form a set B2.

[0022] S4, selecting the intersection of the set A1, the set A2, and the set A3 to form a set A, selecting the intersection of the set B1 and the set B2 to form a set B, and taking the intersection of the set A and the set B as the final selected excellent color-changing family to be cultivated according to steps S1 and S2 and to build a maple forest.

[0023] Further, in step S1, the seeds of Liquidambar formosana are collected in October to November, then the seeds are soaked in water for 48 hours in January to February of the next year, and then the seeds are placed on the sand bed after being disinfected by 0.2% potassium permanganate, and the sand bed is kept moist by spraying water regularly every day, and the seedlings are taken out and the roots are cut off after 30 to 40 days and the seedlings grow to 1 to 2 cm, and then the seedlings are transplanted into the non-woven fabric bag filled with the substrate and placed in the seedbed for cultivation.

[0024] Further, the seedlings are transplanted into the non-woven fabric bag filled with the substrate and placed in the seedbed for cultivation, and the seedlings are shaded by the shading net with a light transmittance of 40% to 50%; leaf fertilizer is applied twice a month from May to September, and the application of leaf fertilizer is stopped after October; in the rainy season when the air temperature is higher than 25°C, 0.1% thiophanate-methyl aqueous solution or 0.4% carbendazim aqueous solution is sprayed once every 15 days (to prevent the occurrence of damping-off, sudden collapse disease, root rot and other diseases), and if snails are found, 6% tetramethylene aldehyde methoxychlor granules are used for prevention and control.

[0025] Further, the substrate comprises the following components in parts by weight: humus soil 35 to 45 parts, rotten coconut husk 40 to 50 parts, fermented mushroom residue 4 to 6 parts, and perlite 8 to 15 parts; and the leaf fertilizer comprises the following components in mass fraction: 0.3 to 0.5% of compound fertilizer, 0.1% of nitrogen fertilizer, and the balance of water. The substrate and leaf fertilizer suitable for the growth of Liquidambar formosana are prepared to provide the required nutrients for the growth of Liquidambar formosana.

[0026] Further, the ratio of N:P2O5:K2O in the compound fertilizer is 15:15:15, and the nitrogen fertilizer is urea.

[0027] Further, in step S2, the soil is loosened and weeded once a year from July to August, and the weeds and shrubs that affect the growth of the trees in the forest land are cut off, and the soil is loosened in a range of 50 cm to the left and right, 60 cm above, 40 cm below, and 20 cm deep around the plant.

[0028] Further, in step S3, the single plant discoloration amount is the percentage of the number of discolored leaves of each Liquidambar formosana to the total number of leaves, and the single plant discoloration amount is set to 11 gradients, and each 10% is a gradient, and the single plant discoloration amount when all the leaves are not discolored (i.e. green) is 0%, and the single plant discoloration amount when all the leaves are discolored is 100%.

[0029] The technical solution has the following beneficial effects compared with the prior art:

[0030] 1、The method meets the requirements of the industry standard "Guidelines for Testing Specificity, Consistency and Stability of New Plant Varieties Acer" (LY / T 3207-2020) and the Guangxi local standard "Technical Specifications for the Approval of Ornamental Plant Varieties" (DB 45 / T 1781-2018), and through scientific breeding (including regional testing, propagation and cultivation, test forest determination, selection and evaluation of leaf color index and growth index, etc.), the selected excellent family of Acer is not only strong in adaptability and healthy in growth, but also bright in leaf color and good in ornamental effect, which can greatly play the ornamental value of Acer.

[0031] 2、The evaluation of different Acer family lines in the test forest includes leaf color index and growth index, wherein the leaf color index is composed of leaf color system, single plant color change amount and leaf CIE-Lab color space parameters, and the growth index is composed of preservation rate and leaf health degree, through the determination and analysis of the leaf color index, not only the Acer family line with good color change stability can be effectively evaluated and selected, but also the Acer family line with a score not less than 60 points can be effectively screened out according to the scoring of the leaf CIE-Lab color space parameters, which can effectively screen out the excellent Acer family line with good leaf color specificity (bright red leaf) and good ornamental effect; meanwhile, combined with the growth index, the Acer family line with strong adaptability and healthy growth can be screened out, so that the excellent Acer family line with strong adaptability, healthy growth and good color change effect is obtained, which is suitable for popularization and application in cultivating color forest and effectively improving the landscape value and tourism value of forest. BRIEF DESCRIPTION OF DRAWINGS

[0032] Figure 1 is a measurement position diagram selected on the leaf during the measurement of the leaf color parameter in step S33 in embodiment 1.

[0033] Figure 2 is a result diagram of each score node color information in the final score library in step S37 in embodiment 1.

[0034] Figure 3 is a single plant diagram of Acer with a score of 70 points during the measurement of the leaf CIE-Lab color space parameters in step S37 in embodiment 1.

[0035] Figure 4 is a single plant diagram of Acer with a score of 60 points during the measurement of the leaf CIE-Lab color space parameters in step S37 in embodiment 1.

[0036] Figure 5 is a single plant diagram of Acer with a score of 50 points during the measurement of the leaf CIE-Lab color space parameters in step S37 in embodiment 1.

[0037] Figure 6 is a picture of No. 11 Acer family line after cultivation in embodiment 1.

[0038] Figure 7 is the picture of the cultivation of No. 78 maple family in Example 1.

[0039] Figure 8 is the picture of the cultivation of No. 100 maple family in Example 1.

[0040] Figure 9 is the picture of the cultivation of No. 142 maple family in Example 1.

[0041] Figure 10 is the picture of the cultivation of No. 237 maple family in Example 1. DETAILED DESCRIPTION

[0042] The present application is further illustrated by the following examples, but not as a limitation to the present application. The specific experimental conditions and methods not specified in the following examples, and the technical means adopted are generally the conventional means familiar to those skilled in the art.

[0043] Example 1: According to the maple elite breeding method based on the leaf color evaluation of colorful maple leaves described in the present application, the breeding of excellent maple family is carried out, and the specific process is as follows:

[0044] S1, in 2017, with the support of the Guangxi Zhuang Autonomous Region Finance Forest Tree Variety Special Project “Guangxi Indigenous Colorful Leaf Tree Species Germplasm Resource Preservation and Utilization”, 11 maple sources and 233 families were collected in Guangxi Zhuang Autonomous Region and Guizhou Province, and in January 2018, 70,000 high-quality seedling trees were cultivated in the self-built nursery of Guangxi Zhuang Autonomous Region Forestry Science Research Institute (Nanning, Guangxi), and 136 families that can be used for the design of test forest seedling trees were obtained;

[0045] The propagation process includes the following contents:

[0046] S11, in October-November, collect maple seeds and dry them in the sun, remove impurities after the seeds are removed, collect pure seeds, and store them in a 4°C refrigerator for standby;

[0047] S12, in January-February of the next year, after the seeds are soaked for 48 hours, they are then disinfected with 0.2% potassium permanganate, then spread on sand bed for germination, and keep the sand bed moist by watering regularly every day. After 30-40 days of sowing, when the seedlings are 1-2 cm long, transplant the seedlings;

[0048] S13, pick loose sand with tools to take out seedlings, cut off the main root, the main root length is reserved 2cm-4cm; with tools in the middle of the nutrient bag insert a small hole, the depth is 4cm-6cm, vertical put seedlings after from the side gently compacted substrate, spray enough rooting water; the substrate comprises the following components by weight: humus soil 40 parts, rotten coconut shell 45 parts, fermented mushroom residue 5 parts, perlite 10 parts, the substrate can also add 0.1% of the total weight of the substrate compound microbial agent;

[0049] S14, the transplanted seedlings are placed in the seedbed, and the shading net with a light transmittance of 40%-50% is used to shade in time, and the shading net is removed after October; during the fast-growing period of the seedlings, water is sprayed in time according to the water content of the substrate, and topdressing is carried out, and then water is sprayed in time; from May to September, leaf fertilizer is applied twice a month, and fertilization is stopped after October; the principle of "early removal, small removal and removal" is adopted for weeding, artificial weeding is adopted to avoid taking seedlings and damaging roots; in the rainy season when the air temperature is higher than 25℃, 0.1% thiophanate-methyl solution or 0.4% carbendazim solution is sprayed once every 15 days to prevent the occurrence of damping-off, sudden collapse disease and root rot disease; if snails and other pests are found, use snail killer (6% tetramic acid carbaryl) granules for control; the leaf fertilizer comprises the following components by mass fraction: 0.3-0.5% of compound fertilizer, 0.1% of nitrogen fertilizer, and the balance of water; the ratio of N:P2O5:K2O in the compound fertilizer is 15:15:15; the nitrogen fertilizer is urea.

[0050] S2, selecting high-quality seedlings with a height of more than 40 cm to build test forests, which specifically includes the following contents:

[0051] S21, three test points are designed, and a completely randomized block design is used for each test point; each test point has 136 families; the test forest locations and their climate and soil conditions are as follows:

[0052] The Nanning test point is located in the Dongsheng Branch of Gaofeng State-owned Forest Farm in the northern suburbs of Nanning (E 108.407515°, N 22.981340°), with an altitude of 130 m, belonging to the south subtropical monsoon climate, with an annual average temperature of 21.6 ℃ and an annual rainfall of 1350 mm; the soil is mainly yellow-red soil, and the soil layer is more than 1.0 m thick;

[0053] The Liuzhou test point is located in the Boxing Branch of Huangchuan State-owned Forest Farm in Luzhou City (E 109.884329°, N 22.780638°), with an altitude of 200 m, belonging to the subtropical monsoon climate, with an annual average temperature of 19.0 ℃ and an annual rainfall of 1750 mm; the soil is mainly yellow-red soil, and the soil layer is more than 1.0 m thick;

[0054] Hezhou test point: located in Liupai Branch of Dagui Mountain State Forest Farm in Bubu District of Hezhou City (E 111.730266°, N 24.7174602°), with an altitude of 150 m, belonging to subtropical monsoon climate, with an average annual temperature of 21.2 ℃ and an annual rainfall of 1940 mm; the soil is mainly yellow-red soil, with a soil thickness of 0.8-1.0 m;

[0055] S22, in each test point, 15 plants of each family are planted, and 5 plants are planted in a single row as a small area; the afforestation density is 110 plants per mu, and the plant row spacing is 2 m x 3 m; the three test points are all machine plowing, artificial hole planting, with a specification of 60 cm (hole surface width) x 40 cm (hole bottom width) x 40 cm (hole depth), and 500 g of compound fertilizer is put in each hole before planting;

[0056] S23, complete planting in January-April 2019, investigate survival rate one month after afforestation, and replant, complete soil loosening and weeding once in July-August; complete 500 g of compound fertilizer per plant in May-June 2020, combined with fertilization, soil loosening and weeding; spray pesticides in April 2021 for disease and pest control, complete 500 g of compound fertilizer per plant and weed in May-June; spray pesticides in April 2022 for disease and pest control, complete 500 g of compound fertilizer per plant and weed in May-June; spray pesticides in May 2023 for disease and pest control, and weed in June.

[0057] S3, after the establishment of the test forest, the test forest is measured at the peak of leaf color change in December every year, that is, when more than 80% of the plants with more than 70% of the leaves completely changed account for more than 80% of the total plants; the measured indexes include leaf color index and growth index; the leaf color index includes leaf color system, single plant color change amount, and leaf CIE-Lab color space parameters (brightness L, red-green attribute a, yellow-blue attribute b); the growth index includes survival rate and leaf health degree;

[0058] The test forest is measured in December 2019, mainly to determine the appropriate measurement period of the liquidambar formosana plant and the breeding standard, therefore, the measurement data do not participate in the breeding analysis; then the liquidambar formosana test forest of the three test points is measured for three consecutive years in 2020, 2021 and 2022, the specific measurement indexes, measurement steps and requirements are as follows:

[0059] S31, leaf color system: the leaf color system is divided into red, yellow, orange and green, the color of each liquidambar formosana plant is determined by visual observation using a color comparison card;

[0060] S32, single plant discoloration amount: the single plant discoloration amount is the percentage of the number of discolored leaves of each plant to the total number of leaves, and the single plant discoloration amount is set to 11 gradients, every 10% is a gradient, the single plant discoloration amount when all leaves are not discolored (i.e. green) is 0%, and the single plant discoloration amount when all leaves are discolored is 100%; if the single plant discoloration amount is between 50% and 70%, 3 people need to observe and determine the discoloration amount after statistics;

[0061] S33, leaf CIE-Lab color space parameters: in the expression of color range, Lab mode is the most complete in the current color expression mode, the defined color is the most, and is independent of light and equipment, which is a color system based on physiological characteristics; therefore, selecting CIE-Lab color space can accurately and objectively quantify the color of maple leaves;

[0062] The leaf CIE-Lab color space parameters are that in each plot, plants with a single plant discoloration amount greater than or equal to 70% are selected, 3-6 leaves are collected, then 3 leaves are randomly selected and wiped to remove surface dust, and a color difference meter (Hangzhou Color Spectrum Spectrophotometer CS-650) is used to measure the leaf color parameters. When measuring, use a 8 mm diameter window under D65 light source and angle 10° to measure the front color of the leaf, measure 10 positions of each leaf (such as Figure 1 ) and calculate the average value; the leaf color parameters include lightness L value (the larger the L value, the brighter the leaf color), red-green attribute a value (the larger the a value, the more the leaf color is biased towards red), and yellow-blue attribute b value (the larger the b value, the more the leaf color is biased towards yellow);

[0063] S34, survival rate: the survival rate is the number of surviving plants in each plot of 5 plants in a single row;

[0064] S35, leaf health degree: the collected leaves are scanned by a scanner, and then the scanned picture is imported into a plant image analyzer (Wandep LA-S series plant image analyzer) to count the area of leaf lesions, insect damage and wilting, and calculate the percentage of the total area of lesions, insect damage and wilting to the total leaf area, i.e. the leaf health degree.

[0065] According to the above determination standard, excellent maple family varieties are screened, and the specific process is as follows:

[0066] S36, evaluate the single plant growth adaptability with the 2022 preservation rate, if the preservation rate of a family in each plot is greater than or equal to 3, it indicates that the family adaptability is better, mark the maple variety of the family as a standard variety, and all the standard varieties form a set A3; the single plant color change amount determination data is screened, if the single plant color change amount of at least 3 plants of a family in each plot is greater than or equal to 70%, the maple variety of the family is marked as a standard variety, and all the standard varieties form a set A2; at the same time, if at least 3 plants of a family in each plot are consistent in color system for 3 consecutive years (2020, 2021 and 2022), the maple variety of the family is marked as a standard variety, and all the standard varieties form a set A1;

[0067] S37, after 3 years of determination, the maple leaf color system is green, red, yellow and orange. Among them, yellow and orange are both mixed from green and red, and are between green and red in the international general color library;

[0068] Taking positive green and positive red as the standard, the lightness L value, red-green attribute a value and yellow-blue attribute b value of the leaf color parameter are converted into standardized scores, the positive green color is assigned as 0 points, and the positive red color is assigned as 100 points, according to the L, a, b values of the positive green and positive red colors, the color difference ΔE0 between the two is calculated according to the color difference calculation formula, and the L i 、a i 、b i value of the collected leaf and the L 红 、a 红 、b 红 value of the positive red color are calculated to calculate the color difference ΔE1, and finally the color standardization score S of the collected leaf is calculated by calculating the ratio of ΔE1 and ΔE0;

[0069] The L 红 =54, a 红 =81, b 红 =70 and L 绿 =88, a 绿 =-79, b 绿 =81 in the positive green and positive red parameters in the international general color library are determined, and the specific calculation formula is as follows:

[0070] Δ E 0=[(Δ L ) 2 +(Δ a ) 2 +(Δ b ) 2 ] 0.5 =[(-34) 2 +(160) 2 +(-11) 2 ] 0.5 =163.94

[0071] Δ L = L 红 - L 绿 =54-88;Δ a = a 红 - a 绿 =81-(-79);Δ b = b 红 - b 绿 =70-81

[0072] ΔE1= [(Δ L i ) 2 +(Δ a i ) 2 +(Δ b i ) 2 ] 0.5

[0073] Δ L i = L 红 - L i =54- L i ;Δ a i = a 红 - a i =81- a i ;Δ b i = b 红 - b i =70- b i

[0074] S =100-(ΔE1 / Δ E 0) ×100=100-(ΔE1 / 163.94) ×100;

[0075] The color standardization scores of all collected leaves were calculated according to the above formula to obtain the color standardization score library of maple leaves. However, since both positive green and positive red are one of the three primary colors, it is difficult to achieve in nature. Therefore, in order to facilitate comparison, the highest score (60.80, L=41.07, a=37.84, b=24.17) and the lowest score (32.94, L=28.69, a=1.47, b=-1.55) in the color standardization score library of maple leaves were selected to replace the positive red and the positive green respectively. The scores of the collected leaf colors were recalculated according to the above formula to obtain the final score library, and ranking was performed. The color information of each score node is shown in Table 1 and Figure 2 The photos of maple leaves corresponding to some scores are shown in Figures 3-5 ;

[0076] Table 1 Color information of each score node in the final score library

[0077]

[0078] According to the industry standard "Guidelines for Specificity, Uniformity and Stability Test of New Plant Varieties Maple", the difference constant is used to evaluate the trait specificity, that is, the difference between the test material and the similar variety is very clear. As can be seen from Table 1 and Figures 2-5 , the leaf color with a final score of ≥60 is red and bright, and the ornamental effect is better than that of the leaf color with a score of less than 50. Therefore, the leaf color with a score of ≥60 is regarded as the specificity of maple leaf color. The scores of some families and the analysis are shown in Table 2 and Table 3 (Y represents year, S represents test site, R represents test plot, and I represents individual. I(R(S(Y))) represents that I is nested in R, R is nested in S, and S is nested in Y);

[0079] Table 2 Leaf color scores of some families in each test site in three years

[0080]

[0081] Table 3 Variance analysis of nested design of some families

[0082]

[0083] After ranking the scores of the collected leaves in each plot, the final score of ≥60 was selected. Then, taking year, test site, plot, and individual as independent variables, and taking the final score as dependent variable, multi-factor variance analysis was performed on each selected family. If the year, test site, plot, and individual have no significant effect on the score of the family number, the family number meets the stability and uniformity principles, and is further selected to form a selected subset B1.

[0084] S38, if the health of the leaves of at least 3 plants in each plot is less than 10%, the maple variety of the family is marked as a qualified variety, and all qualified varieties form a set B2;

[0085] S4, by analyzing the growth data of the maple test forest in 2023 and the single plant discoloration data of 3 years, the intersection of set A1, set A2 and set A3 is selected to form set A, which includes 11, 78, 87, 100, 105, 142, 228, 237, 8 families; The intersection of set B1 and set B2 forms set B, which includes 11, 78, 100, 142, 237, 5 families; The intersection of set A and set B is the final selected excellent discoloration family, which is 11, 78, 100, 142, 237, 5 families of maple varieties, and the cultivation pictures of the test forest of the 5 families are as follows Figures 6-10 ;

[0086] S5, take 11, 78, 100, 142, 237, 5 families of maple varieties for cultivation, the cultivation afforestation process includes the following contents:

[0087] S51, afforestation site preparation: the planting method is to plant in clear ridge, the plant spacing is 2m x 3m, and the ridge density is 110 plants per mu; The ridge specification is 30cm x 30cm x 30cm; 0.5kg of organic-inorganic compound fertilizer per plant is used as base fertilizer;

[0088] S52, planting: choose the environment with sufficient rain and moist forest soil for afforestation, complete the survival rate investigation within 30 days after planting, and appropriately supplement the planting;

[0089] S53, tending: tending once a year from July to August, cutting grass and expanding ridge, cutting off weeds and shrubs in the forest land that affect the growth of trees, taking the plant as the center, 50cm to the left and right, 60cm above, 40cm below, and 20cm deep, and loosening the soil;

[0090] S54, topdressing: topdressing once a year from May to July, and continuous fertilization for 3 years. Dig a fertilization ditch at a suitable position from the tree root, evenly apply 0.15-0.25kg of fertilizer in the fertilization ditch, and mainly use compound fertilizer as the type of fertilizer. Cover the soil after fertilization to prevent fertilizer loss;

[0091] S55, forest management: safety training, construction training, safety drug distribution, propaganda slogans, banner pasting and other work for construction personnel; Collect relevant data and do a good job in archiving. At the same time, do a good job in forest fire prevention, disease and pest control, and human damage control.

[0092] Furthermore, it should be understood that although the specification is described in terms of embodiments, not every embodiment includes every feature described. The specification can include implicit combinations of explicitly mentioned features and / or explicit combinations of implicitely mentioned features. Each embodiment depends on the explicit combinations of features and / or the implicit combinations of features made specifically within that embodiment, and each such embodiment can be combined with every other such embodiment to create further embodiments.

Claims

1. A method for breeding improved varieties of Liquidambar formosana based on leaf color evaluation of colored liquidambar formosana, characterized by: The following steps are involved: S1. Collect seeds of Liquidambar formosana from different families and propagate them to obtain seedlings with a height greater than 40 cm; S2. Using the seedlings described in step S1 to establish a test forest, which specifically includes the following: The afforestation experiment was divided into three or more test sites. Within each test site, each family planted 15 trees, with each plot consisting of 5 trees in a single row. The planting density was 110 trees per mu, with a row spacing of 2 m × 3 m. Planting took place from January to April of the same year, with a planting hole size of 60 cm wide, 40 cm wide at the bottom, and 40 cm deep. Before planting, 500 g of compound fertilizer was applied to each hole. One month after planting, the survival rate was assessed, and replanting was carried out. Pesticides were sprayed for pest and disease control in April each year, and compound fertilizer was applied at a rate of 500 g per plant from May to June each year. The soil was loosened and weeded once a year from July to August. S3. After the experimental forest is established, measurements will be conducted in December each year when the leaves of Liquidambar formosana are at their peak color change, that is, when more than 70% of the plants with fully changed leaves account for more than 80% of the total plants. The measured indicators include leaf color indicators and growth indicators; the leaf color indicators include leaf color system, single plant color change amount, and leaf CIE-Lab color space parameters; The leaf color is divided into red, yellow, orange and green. The leaf color of each sweetgum plant is determined by visual observation using a color chart. If at least three plants in a family in each plot have the same color for three consecutive years, the sweetgum varieties of that family are marked as meeting the standard. All the varieties meeting the standard are grouped into set A1. The individual plant discoloration rate is calculated by counting the percentage of discolored leaves of each Liquidambar variety relative to the total number of leaves. If the individual plant discoloration rate of at least three plants in each plot of a family is greater than or equal to 70%, the Liquidambar varieties of the family are marked as meeting the standard, and all the varieties meeting the standard are grouped into set A2. The leaf CIE-Lab color space parameters are as follows: in each plot, plants with a color change of greater than or equal to 70% are selected, 3 to 6 leaves are collected, and then 3 leaves are randomly selected to wipe the surface dust and use a colorimeter to measure the leaf color parameters. During the measurement, the front color of the leaf is measured using an 8 mm diameter window under a D65 light source and an angle of 10°. Ten positions on each leaf are measured and the average value is calculated. The leaf color parameters include lightness L value, red-green attribute a value, and yellow-blue attribute b value. Taking true green and true red as the standard, the lightness L value, red-green attribute a value, and yellow-blue attribute b value of the leaf color parameters are converted into standardized scores, with true green being assigned 0 points and true red being assigned 100 points. According to the L, a, and b values ​​of true green and true red, the color difference ΔE0 between the two is calculated according to the color difference calculation formula to collect leaf L i 、a i 、b i Value and positive red L 红 、a 红 、b 红 The color difference ΔE1 is calculated, and finally the color standardization score S of the collected leaves is calculated by calculating the ratio of ΔE1 to ΔE0, where L 红 =41.07, a 红 =37.84, b 红 =24.17 and L 绿 =28.69, a 绿 =1.47, b 绿 =-1.55, the specific calculation formula is as follows: D E 0=[(D L ) 2 +(D a ) 2 +(D b ) 2 ] 0.5 ; D L = L 红 - L 绿 ;D a = a 红 - a 绿 ;D b = b 红 - b 绿 ; ΔE1= [(Δ L i ) 2 +(D a i ) 2 +(D b i ) 2 ] 0.5 ; D L i = L 红 - L i ;D a i = a 红 - a i ;D b i = b 红 - b i ; S =100-(ΔE1 / Δ E 0) ×100; If a family has at least three plants with a color selection standardized score S greater than or equal to 60 in each plot at each test site within three years, a nested design variance analysis is conducted on the family with year, test site, plot, and individual plant as independent variables and score as the dependent variable. If the effects of year, test site, plot, and individual plant on the score are not significantly different, the Liquidambar varieties of the family are marked as meeting the standard, and all the varieties meeting the standard are grouped into set B1. The growth indicators include preservation rate and leaf health; The survival rate is the number of surviving plants in a single row of 5 plants in each plot. If the survival rate of a family in each plot is greater than or equal to 3, the liquidambar varieties of the family are marked as meeting the standards, and all the varieties meeting the standards are grouped into set A3. The leaf health is determined by scanning the collected leaves with a scanner, then importing the scanned images into a plant image analyzer to count the areas of leaf lesions, insect damage, and rot, and calculating the percentage of the sum of the areas of lesions, insect damage, and rot to the total leaf area. If the leaf health of at least three plants in each plot of a family is below 10%, the liquidambar varieties of that family are marked as meeting the standards, and all the varieties meeting the standards are grouped into set B2. S4. Select the intersection of set A1, set A2 and set A3 to form set A, select the intersection of set B1 and set B2 to form set B, and then use the intersection of set A and set B as the final selected excellent color-changing family to cultivate and build a liquidambar forest according to steps S1 and S2.

2. The method for breeding improved varieties of Liquidambar formosana based on leaf color evaluation of colored liquidambar formosana according to claim 1, characterized in that: In step S1, seeds are collected from a single Liquidambar formosana plant in October or November, and then the seeds are soaked in water for 48 hours in January or February of the following year. The seeds are then disinfected with 0.2% potassium permanganate and spread on a sand bed for germination. Watering is performed regularly every day to keep the sand bed moist. When the seedlings grow to 1 to 2 cm 30 to 40 days after sowing, the seedlings are removed and their roots are cut, with the main root length retained at 2 to 4 cm. The seedlings are then transplanted and placed in a non-woven bag filled with a substrate, and then placed in a seedbed for cultivation.

3. The method for breeding improved varieties of Liquidambar formosana based on leaf color evaluation of colored liquidambar formosana according to claim 1, characterized in that: Transplant the seedlings into a non-woven bag filled with substrate, and then place them in the seedbed for cultivation, using a shade net with a light transmittance of 40% to 50% for shading; apply foliar fertilizer twice a month from May to September of the same year, and stop applying foliar fertilizer after October; in the rainy season when the temperature is above 25°C, spray once every 15 days with a 0.1% thiophanate-methyl aqueous solution or a 0.4% carbendazim aqueous solution. If snails are found, use 6% metaldehyde and carbaryl granules for prevention and control.

4. The method for breeding improved varieties of Liquidambar formosana based on leaf color evaluation of colored liquidambar formosana according to claim 3, characterized in that: The matrix comprises the following components in parts by weight: 35-45 parts of humus soil, 40-50 parts of decomposed coconut husks, 4-6 parts of fermented mushroom residues, and 8-15 parts of perlite; the foliar fertilizer comprises the following components in parts by mass: 0.3-0.5% of compound fertilizer, 0.1% of nitrogen fertilizer, and the balance being water.

5. The method for breeding improved varieties of Liquidambar formosana based on leaf color evaluation of colored liquidambar formosana according to claim 4, characterized in that: The ratio of N:P2O5:K2O in the compound fertilizer is 15:15:15; and the nitrogen fertilizer is urea.

6. The method for breeding improved varieties of Liquidambar formosana based on leaf color evaluation of colored liquidambar formosana according to claim 1, characterized in that: In step S2, the soil is loosened and weeded once in July and August every year. Specifically, the weeds and shrubs that affect the growth of trees in the woodland are cut down, and the soil is loosened within an area of ​​50 cm to the left and right, 60 cm above, 40 cm below, and 20 cm deep, centered on the plant.

7. The method for breeding improved varieties of Liquidambar formosana based on leaf color evaluation of colored liquidambar formosana according to claim 1, characterized in that: In step S3, the color change amount of a single plant is the percentage of the number of colored leaves of each Liquidambar formosana plant to the total number of leaves, and the color change amount of a single plant is set to 11 gradients, with each 10% being a gradient. The color change amount of a single plant when all leaves have not changed color is 0%, and the color change amount of a single plant when all leaves have changed color is 100%.

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