Phosphorus-efficient choerospondias axillaris family breeding method

Abstract

The invention discloses a phosphorus-efficient choerospondias axillaris family breeding method, and relates to the technical field of agricultural breeding, and the method comprises the following steps: step S4, index calculation, and according to the above data, selecting the choerospondias axillaris family; calculating the root-crown ratio, the total phosphorus utilization efficiency, the low-phosphorus stress resistance coefficient of each index, the membership function value of the comprehensive index, the weight of each comprehensive index, the comprehensive value of the low-phosphorus resistance efficiency, and the comprehensive value of the phosphorus efficiency under different phosphorus supply conditions; and S5, screening low-phosphorus-resistant identification key indexes, performing stepwise regression analysis by taking the low-phosphorus-resistant efficiency comprehensive evaluation value as a dependent variable and the low-phosphorus-resistant stress coefficient of the measured index as an independent variable to obtain a multiple regression equation, and screening out the low-phosphorus-resistant identification index of the choerospondias axillaris. The problems of long time consumption, large workload, no breeding system and the like of the traditional breeding method are solved. According to the method, the choerospondias axillaris families which are resistant to low phosphorus and efficient in phosphorus and aim at the problem that phosphorus in soil is generally lacked are screened out preferentially, existing germplasm resources are sequenced according to screening targets, optimal germplasm resources are screened out, and the target range is narrowed.

Description

Technical Field

[0001] The invention relates to the technical field of agricultural breeding, and in particular to a method for breeding a family of Choerospondias axillaris with high phosphorus efficiency. Background Art

[0002] The current situation of widespread lack of available phosphorus in forest soils in southern my country, especially in difficult sites, is that the large-scale application of phosphorus fertilizers has caused serious environmental problems. Under this background, in order to promote the creation of green, high-quality, high-yield and high-efficiency core seed sources, it is urgent to cultivate phosphorus-efficient varieties from the perspective of the plant itself. Choerospondia saxillaris is a large deciduous tree in the Anacardiaceae family, which has wood, fruit and medicinal value. It is an important and precious native tree species in southern my country and one of the important pioneer tree species for vegetation restoration in difficult sites such as rocky desertification areas, industrial and mining areas, and purple soils. By making full use of the inherent biological characteristics of different families of Choerospondia saxillaris, the Choerospondia saxillaris families with low phosphorus tolerance and high phosphorus nutrition efficiency were selected, which greatly improved the efficiency of cultivating new varieties with high phosphorus nutrition efficiency, which has important practical significance for vegetation restoration in difficult sites and "weight loss and efficiency increase". At present, there is still a lack of systematic breeding methods for Choerospondia saxillaris with high phosphorus nutrition. Summary of the invention

[0003] In order to solve the above technical problems, the present invention provides a method for breeding a family of Choerospondias axillaris with high phosphorus nutrition, comprising the following steps:

[0004] Step S1: selecting and breeding seed lines, selecting the Choerospondias axillaris with superior tree height, diameter at breast height, etc. and no diseases or insect pests as superior trees for registration, and harvesting the Choerospondias axillaris fruits of each superior tree; removing the pulp of the Choerospondias axillaris fruits and drying the seeds in a cool and ventilated place;

[0005] Step S2: soil selection, select rocky desertification mountain soil with poor nutrition, measure the soil pH value and nutrient content, apply urea to adjust the soil hydrolyzable nitrogen content one month before the pot experiment, and then divide the soil into two parts;

[0006] Step S3: raising seedlings, raising the seeds by stratification germination method, and hardening the seedlings 7-10 days before the seedlings grow to the transplanting standard to obtain Choerospondias australis seedlings;

[0007] Step S4: screening experiment, selecting Choerospondias axillaris seedlings with similar growth conditions in each family and transplanting them into test pots, placing the test pots in a rain shelter, and adding water appropriately according to soil humidity;

[0008] After 3-4 months of cultivation, the diameter of the ground, seedling height, root morphology, relative chlorophyll content of leaves, biomass of the root system and aboveground parts, and phosphorus content of each experimental group were investigated and measured.

[0009] Step S5: Indicator calculation, based on the above data, the root-to-shoot ratio, total phosphorus utilization efficiency, the low-phosphorus stress tolerance coefficient of each indicator, the membership function value of the comprehensive indicator, the weight of each comprehensive indicator and the comprehensive value of low-phosphorus tolerance efficiency are calculated;

[0010] Step S6: screening key indicators for low-phosphorus tolerance identification, taking the comprehensive evaluation value of low-phosphorus tolerance efficiency as the dependent variable and the low-phosphorus tolerance coefficient of the measured indicator as the independent variable, performing stepwise regression analysis to obtain a multiple regression equation, and screening out the identification indicators for low-phosphorus tolerance of Choerospondias axillaris;

[0011] Step S7: analysis and classification, calculating the comprehensive values ​​of low phosphorus tolerance efficiency of seedlings of different families under normal phosphorus levels and low phosphorus stress, and performing scatter plot analysis to classify their low phosphorus tolerance efficiency into four categories, namely, category I low phosphorus high efficiency and normal phosphorus high efficiency type, category II low phosphorus high efficiency and normal phosphorus low efficiency type, category III low phosphorus low efficiency and normal phosphorus low efficiency type, and category IV low phosphorus low efficiency and normal phosphorus high efficiency type;

[0012] Step S8: Field trials and final screening, combining the comprehensive value of low-phosphorus tolerance efficiency and the scatter point analysis of the comprehensive value of low-phosphorus tolerance efficiency to determine the phosphorus-efficient germplasm resources, raising seedlings of the screened out phosphorus-efficient Choerospondias axillaris families and conducting field trials, and conducting afforestation trials on the selected one-year-old Choerospondias axillaris family seedlings in difficult rocky desertification sites and general hilly and mountainous areas, regularly observing their growth traits such as tree height, breast diameter, crown width, and tree shape, and determining the Choerospondias axillaris families with high phosphorus nutrition after layers of screening and verification.

[0013] Furthermore, in step S1, the seeds are dried in a cool and ventilated place for 2 to 4 days until the seed coat turns white and then stored in a 4°C refrigerator or in sand.

[0014] Furthermore, in step S2, the soil hydrolyzable nitrogen content is adjusted to 60.0 mg kg -1 .

[0015] Furthermore, in step S2, one of the two soils is added with potassium dihydrogen phosphate to adjust the effective phosphorus content of the soil to 16.0-20 mg kg -1 .

[0016] Further, the selected seeds are surface disinfected by soaking them in 0.1%-0.2% potassium permanganate solution for 15-30 minutes, or 0.5%-1% copper sulfate solution for 10-20 minutes, and then rinsed with clean water to remove germs and impurities on the seed surface and reduce the occurrence of seedling diseases;

[0017] Using the stratification method, the sterilized seeds are mixed with moist river sand or perlite in a volume ratio of 1:3-1:5. The mixed seeds and substrate are placed in a low temperature environment (0

[0018] -5℃) for stratification, which usually takes 60-90 days. During the stratification process, check the humidity of seeds and substrate regularly, and keep the substrate moist but not waterlogged to promote the completion of seed ripening and improve germination rate;

[0019] Furthermore, in step S4, the sowed jujube seedlings are sown in mid-March and transplanted when the sowed jujube seedlings reach a height of 10-12 cm in late April.

[0020] Furthermore, in step S4, the experimental pots are round-bottomed flower pots with a diameter of 20.0 cm and a height of 18.0 cm, and each pot is filled with 3.0 kg of experimental soil.

[0021] Furthermore, in step S4, water is added once every 2 to 3 days, with 0.3-0.5 L of water being added to each pot each time.

[0022] Furthermore, in step S7, the Class I low-phosphorus, high-efficiency, and normal-phosphorus high-efficiency types are selected as the preferred phosphorus high-efficiency germplasm resources, followed by the Class II low-phosphorus, high-efficiency, and normal-phosphorus low-efficiency types.

[0023] The present invention provides a method for breeding a family of Choerospondias axillaris with high phosphorus nutrition, which has the following beneficial effects:

[0024] The method for selecting and breeding a family of Choerospondias axillaris with high phosphorus nutrition of the present invention makes up for the problems of the traditional breeding method, such as long time consumption, large workload, and no breeding system. In the specific implementation process, the method of the present invention is used to preferentially screen out a family of Choerospondias axillaris with low phosphorus tolerance and high phosphorus efficiency for the problem of general lack of soil phosphorus, and the existing germplasm resources are sorted according to the screening target, the preferred germplasm resources are screened out, the target range is narrowed, and the selected family seedlings are used to carry out afforestation experiments in difficult sites such as rocky desertification and general forest land, and surveys are carried out in the 3rd to 5th year. After layers of screening and verification, a family with high phosphorus nutrition efficiency is determined. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 This is a scatter plot of the comprehensive value of phosphorus efficiency of the Choerospondias axillaris family under the two phosphorus supply conditions of the present invention. DETAILED DESCRIPTION

[0026] The present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments. The examples of the present invention are given for the purpose of illustration and description, and are not intended to be exhaustive or to limit the present invention to the disclosed forms. Many modifications and variations will be apparent to those of ordinary skill in the art. The embodiments are selected and described in order to better illustrate the principles and practical applications of the present invention, and to enable those of ordinary skill in the art to understand the present invention and design various embodiments with various modifications suitable for specific uses.

[0027] Example 1: In the initial stage of breeding, we conducted a survey and collection of resources of Achyranthes spinulosus in Hunan, Jiangxi, Hubei and other areas suitable for Achyranthes spinulosus, and selected Achyranthes spinulosus with good tree height, diameter at breast height, and no pests and diseases as superior trees for registration and seed collection. A total of 28 excellent germplasm resources were collected and the fruits of each superior tree were harvested.

[0028] Remove the pulp from the fruit of the Chinese jujube, and air the seeds in a cool and ventilated place for 2 to 4 days. When the seed coat turns white, they can be stored. The seeds should be stored in a refrigerator at 4°C or in sand. They should be sown and raised in March. The seedling raising medium can be made of peat soil, vermiculite, perlite, etc. mixed in a certain proportion. Generally, the ratio of peat soil: vermiculite: perlite = 3:1:1 is more suitable. This mixed medium has good air permeability, water retention and fertility, which is conducive to the germination of seeds and the growth of seedlings of Chinese jujube.

[0029] Add appropriate amount of organic fertilizer and microbial agent to the substrate, such as 10-15 kg of decomposed chicken manure or cow manure and 1-2 kg of biological fertilizer per cubic meter of substrate, to provide nutrients required for seed germination and seedling growth, improve the microbial environment of the substrate, and promote root development;

[0030] After sowing, water thoroughly by spraying to keep the substrate moist. Before the seeds germinate, cover the nursery bed with a layer of plastic film or shade net to maintain temperature and humidity and promote seed germination. When the seeds begin to emerge, remove the covering in time to prevent the seedlings from growing too tall.

[0031] 7-10 days before the seedlings grow to the transplanting standard, start hardening the seedlings, gradually reduce the number and amount of watering, let the seedling medium gradually dry, promote the root system of the seedlings to grow deep, and enhance the root absorption capacity and drought resistance. At the same time, gradually increase the ventilation volume, reduce the humidity of the seedling environment, and make the seedlings adapt to the humidity conditions of the external natural environment.

[0032] Gradually remove shading facilities such as sunshade nets, increase light intensity and duration, adapt seedlings to natural light conditions, and enhance photosynthesis and stress resistance. During the hardening process, pay attention to the growth of seedlings. If abnormal phenomena such as wilting and yellowing are found in seedlings, take timely measures to remedy them, such as appropriate watering and shading. When the seedlings of Choerospondias australis are 10-12 cm tall in late April, carry out phosphorus stress experiments.

[0033] The potting soil was taken from a typical rocky desertified mountain area. The original soil pH was 6.0, the total nitrogen content was 0.05%, the total phosphorus content was 0.03%, and the organic matter content was 6.08 g kg -1 , the effective phosphorus content is 0.2 mg kg -1 , hydrolyzable nitrogen content is 17.0 mg kg -1In the early stage of the study, the effect of different phosphorus concentrations on the growth of Choerospondias axillaris seedlings was studied and it was shown that when the available phosphorus content in the soil reached 16.0 mg kg -1 The comprehensive growth condition of Choerospondias australis seedlings was most ideal when the soil was treated with normal phosphorus supply. Therefore, the soil available phosphorus content in this study was set at 16.0 mg kg -1 , while the available phosphorus content of the soil treated with low phosphorus supply remained at the level of the original rocky desertification soil, i.e. 0.2 mg kg -1 .

[0034] Two months before transplanting, the soil hydrolyzable nitrogen content was adjusted to 60.0 mg kg by applying urea. -1 Random sampling and testing, if the hydrolyzable nitrogen content exceeds 60.0 mg kg -1 , the original rocky desertification soil was added to adjust the hydrolyzable nitrogen content of the test soil. Subsequently, part of the soil was reserved for backup, and the remaining soil was divided into two parts, one of which was adjusted to 16.0 mg kg by adding potassium dihydrogen phosphate. -1 , stir the soil evenly to chelate it, and randomly sample the soil to test the available phosphorus content. If the available phosphorus content is lower than 16.0 mg kg -1 , then potassium dihydrogen phosphate is added for adjustment; if the effective phosphorus content is higher than 16.0 mg kg -1 , then add spare soil to reduce it to the target content to ensure that the experimental design standards are met.

[0035] The experimental pots were round-bottomed pots with a diameter of 20.0 cm and a height of 18.0 cm, and each pot was filled with 3.0 kg of experimental soil. Selected seedlings of Choerospondias australis with similar growth conditions and transplanted into the experimental pots. The experimental pots were placed in a rain shelter, and water was appropriately supplemented according to the soil moisture. Water was poured once every 2 to 3 days, and 0.3-0.5 L of water was poured into each pot each time. After 3 to 4 months of cultivation, the ground diameter, seedling height, root morphology, relative chlorophyll content of leaves, root and aboveground biomass, and total phosphorus content of Choerospondias australis in each experimental group were investigated and measured.

[0036] It was calculated that root-to-shoot ratio = underground dry weight / aboveground dry weight;

[0037] Total phosphorus utilization efficiency = total dry matter mass / total phosphorus accumulation;

[0038] Low phosphorus stress tolerance coefficients of various indicators:

[0039]

[0040] In the formula, X and CK are the measured values ​​of the i-th index under low phosphorus stress and normal phosphorus treatment;

[0041] Comprehensive indicator membership function value:

[0042]

[0043] Where j = 1, 2, 3, n, μ(X j ) represents the membership function value of the jth comprehensive index, X j represents the jth comprehensive index value; X max , X min They represent the maximum and minimum values ​​of the j-th comprehensive index respectively.

[0044] The weight of each comprehensive indicator (W j ):

[0045]

[0046] Where, j = 1, 2, 3, ..., n, W j represents the importance and weight of the jth comprehensive indicator among all comprehensive indicators; P j is the contribution rate of the jth comprehensive indicator of each variety.

[0047] Comprehensive evaluation value of low phosphorus tolerance (D):

[0048]

[0049] In the formula, j = 1, 2, 3, ..., n, according to the comprehensive index membership function value μ (X j) and its weight (W j ), calculate the comprehensive evaluation value D of phosphorus efficiency.

[0050] The comprehensive evaluation value of low phosphorus tolerance efficiency (D) and the comprehensive value of phosphorus efficiency of different Achyranthes axillaris families were calculated. The low phosphorus tolerance of 28 Achyranthes axillaris families was ranked according to the D value: R43>LF001>L46>C46>L56>R32>L49>Y33>L27>Y60>Y34>R36>L33>L37>D double>D single>C35>L43>C56>R27>L45>C44>C2>C51>N single>L44>R5>C52.

[0051] Taking the comprehensive evaluation value of low phosphorus tolerance efficiency (D) as the dependent variable and the low phosphorus tolerance coefficients of the 13 measured indicators as independent variables, a stepwise regression analysis was performed to obtain the multiple regression equation of the dependent variable D value and the 6 independent variables:

[0052] D=0.233+0.19X1+0.082X2-0.334X3+0.099X4+0.082X5+0.04X6;

[0053] (X1 is aboveground weight, X2 is root surface area, X3 is root tissue phosphorus content, X4 is seedling height, X5 is ground diameter, and X6 is total root length) (R2 =0.993, P < 0.01), and the aboveground weight, root surface area, root tissue phosphorus content, seedling height and ground diameter, and total root length were screened out as identification indicators for evaluating the low-phosphorus tolerance of different Choerospondias axillaris families at the seedling stage. This equation can be used to evaluate the low-phosphorus tolerance of different Choerospondias axillaris families.

[0054] The comprehensive values ​​of phosphorus efficiency under different phosphorus supply conditions are plotted as scatter plots, and the phosphorus efficiency is divided into four categories: Figure 1 ): Class I low-phosphorus, high-efficiency, normal phosphorus, high-efficiency type, Class II low-phosphorus, high-efficiency, normal phosphorus, low-efficiency type, Class III low-phosphorus, low-efficiency, normal phosphorus, low-efficiency type, Class IV low-phosphorus, low-efficiency, normal phosphorus, high-efficiency type.

[0055] Table 1 Comprehensive values ​​of phosphorus efficiency of Choerospondias axillaris seedlings under two phosphorus supply levels

[0056]

[0057]

[0058] Through the evaluation of the comprehensive values ​​of phosphorus efficiency and low-phosphorus tolerance of different families, Y34, L27, R32, L56, C46, ​​L46, LF001, R43, D double, L37, and L33 were preliminarily selected to carry out the next afforestation screening test.

[0059] Afforestation experiments were carried out in the rocky desertified mountainous areas of Lianyuan, with a planting density of 56 plants / mu (3*4m). In the third year of afforestation, the afforestation results of each family were investigated, and the high-phosphorus-efficient Choerospondias axillaris family was further selected for afforestation in difficult sites such as rocky desertification.

[0060] Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field and related fields without creative work should fall within the scope of protection of the present invention. The structures, devices and operating methods not specifically described and explained in the present invention are implemented according to the conventional means in the field unless otherwise specified and limited.

Claims

1. A method for breeding a family of Choerospondias axillaris with high phosphorus nutrition, characterized in that: The following steps are included: Step S1: selection and breeding of seed lines, selecting Choerospondias axillaris with superior tree height, diameter at breast height, etc. and no diseases or insect pests as superior trees for registration, and harvesting Choerospondias axillaris fruits from each superior tree; removing the pulp from Choerospondias axillaris fruits and planting seeds in a cool and ventilated place; Step S2: Soil selection: select rocky desertification mountain soil with poor nutrition, apply urea to adjust the soil hydrolyzable nitrogen content one month before the pot experiment, and then divide the soil into two parts; Step S3: raising seedlings, raising the seeds by stratification germination method, and hardening the seedlings 7-10 days before the seedlings grow to the transplanting standard to obtain Choerospondias australis seedlings; Step S4: screening experiment, selecting Choerospondias axillaris seedlings with similar growth conditions in each family and transplanting them into test pots, placing the test pots in a rain shelter, and adding water appropriately according to soil humidity; After 3-4 months of cultivation, the diameter of the ground, seedling height, root morphology, relative chlorophyll content of leaves, biomass of the root system and aboveground parts, and phosphorus content of each experimental group were investigated and measured. Step S5: Indicator calculation, based on the above data, the root-to-shoot ratio, total phosphorus utilization efficiency, the low-phosphorus stress tolerance coefficient of each indicator, the membership function value of the comprehensive indicator, the weight of each comprehensive indicator and the comprehensive value of low-phosphorus tolerance efficiency are calculated; Step S6: screening key indicators for low-phosphorus tolerance identification, taking the comprehensive evaluation value of low-phosphorus tolerance efficiency as the dependent variable and the low-phosphorus tolerance coefficient of the measured indicator as the independent variable, performing stepwise regression analysis to obtain a multiple regression equation, and screening out the identification indicators for low-phosphorus tolerance of Choerospondias axillaris; Step S7: analysis and classification, calculating the comprehensive values ​​of low phosphorus tolerance efficiency of seedlings of different families under normal phosphorus levels and low phosphorus stress, and performing scatter plot analysis to classify their low phosphorus tolerance efficiency into four categories, namely, category I low phosphorus high efficiency and normal phosphorus high efficiency type, category II low phosphorus high efficiency and normal phosphorus low efficiency type, category III low phosphorus low efficiency and normal phosphorus low efficiency type, and category IV low phosphorus low efficiency and normal phosphorus high efficiency type; Step S8: Field trials and final screening, combining the comprehensive value of low-phosphorus tolerance efficiency and the scatter point analysis of the comprehensive value of low-phosphorus tolerance efficiency to determine the phosphorus-efficient germplasm resources, raising seedlings of the screened out phosphorus-efficient Choerospondias axillaris families and conducting field trials, and conducting afforestation trials on the selected one-year-old Choerospondias axillaris family seedlings in difficult rocky desertification sites and general hilly and mountainous areas, regularly observing their growth traits such as tree height, breast diameter, crown width, and tree shape, and determining the Choerospondias axillaris families with high phosphorus nutrition after layers of screening and verification.

2. The method for breeding a family of Choerospondias axillaris with high phosphorus nutrition according to claim 1, characterized in that: In step S1, the seeds are dried in a cool and ventilated place for 2 to 4 days until the seed coat turns white, and then stored in a refrigerator at 4°C or in sand.

3. The method for breeding a family of Choerospondias axillaris with high phosphorus nutrition according to claim 1, characterized in that: In step S2, the soil hydrolyzable nitrogen content is adjusted to 60.0 mg·kg -1 .

4. The method for breeding a family of Choerospondias axillaris with high phosphorus nutrition according to claim 1, characterized in that: In step S2, one of the two soils is treated with potassium dihydrogen phosphate to adjust the effective phosphorus content of the soil to 16.0-20 mg kg -1 .

5. The method for breeding a family of Choerospondias axillaris with high phosphorus nutrition according to claim 1, characterized in that: In step S4, the sowed jujube seedlings are sown in mid-March and transplanted when the sowed jujube seedlings reach a height of 10-12 cm in late April.

6. The method for breeding a family of Choerospondias axillaris with high phosphorus nutrition according to claim 1, characterized in that: In step S4, the experimental pots are round-bottomed flower pots with a diameter of 20.0 cm and a height of 18.0 cm, and each pot is filled with 3.0 kg of experimental soil.

7. The method for breeding a family of Choerospondias axillaris with high phosphorus nutrition according to claim 1, characterized in that: In step S4, water is added by watering once every 2 to 3 days, with 0.3 to 0.5 L of water per pot each time.

8. The method for breeding a family of Choerospondias axillaris with high phosphorus nutrition according to claim 1, characterized in that: In step S5, root-to-crown ratio = underground dry weight / aboveground dry weight; Total phosphorus utilization efficiency = total dry matter mass / total phosphorus accumulation; Low phosphorus stress tolerance coefficients of various indicators: In the formula, X and CK are the measured values ​​of the i-th index under low phosphorus stress and normal phosphorus treatment; Comprehensive indicator membership function value: Where, j = 1, 2, 3, ... n, μ(X j ) represents the membership function value of the jth comprehensive index, X j represents the jth comprehensive index value; X max , X min They represent the maximum and minimum values ​​of the j-th comprehensive index respectively. The weight of each comprehensive indicator (W j ): Where, j = 1, 2, 3, ..., n, W j represents the importance and weight of the jth comprehensive indicator among all comprehensive indicators; P j is the contribution rate of the jth comprehensive indicator of each variety. Comprehensive evaluation value of low phosphorus tolerance (D): In the formula, j = 1, 2, 3, ..., n, according to the comprehensive index membership function value μ (X j) and its weight (W j ), calculate the comprehensive evaluation value D of phosphorus efficiency.

9. The method for breeding a family of Choerospondias axillaris with high phosphorus nutrition according to claim 1, characterized in that: In step S7, the Class I low-phosphorus, high-efficiency, and normal-phosphorus high-efficiency types are selected as the preferred phosphorus high-efficiency germplasm resources, followed by the Class II low-phosphorus, high-efficiency, and normal-phosphorus low-efficiency types.

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