Identification method of restoration type rape variety with strong adaptability to cadmium-polluted farmland

Abstract

The invention belongs to the field of cadmium-polluted farmland remediation, and particularly relates to an identification method of a remediation type rape variety with high adaptability to a cadmium-polluted farmland. By comprehensively evaluating the adaptability of cadmium-polluted farmland, the enrichment and transfer characteristics of cadmium, the removal capacity of cadmium, the economic benefit and the absorption of various trace elements beneficial to a human body of the tested rape variety, an excellent repaired rape variety is obtained; wherein the adaptability of the rape variety to the cadmium-polluted farmland is evaluated through an adaptability index AI. The identification method provided by the invention has comprehensive indexes, and gives consideration to rape adaptability, cadmium enrichment, transfer and removal capabilities, economic benefits and trace elements beneficial to a human body; compared with a traditional method of applying a soil conditioner and the like, the method for planting the tested rape variety in the cadmium-polluted farmland has the advantages that no extra economic investment is needed, no extra cost for the conditioner is needed, rape straws are moved out of the farmland, no secondary pollution risk is caused, and the dual goals of safe production of the rape and farmland pollution remediation can be achieved.

Description

Technical Field

[0001] The invention belongs to the technical field of restoration of cadmium-contaminated farmland, and in particular relates to an identification method for rapeseed varieties with strong adaptability to restoration of cadmium-contaminated farmland. Background Art

[0002] Cadmium is the main pollutant in my country's cultivated soil. Excessive cadmium in the soil affects the safe production of crops. Commonly used cadmium hyperaccumulators include rapeseed, Viola baoshanensis, Houttuynia cordata, Phytolacca americana, Solanum nigrum, Acorus calamus, Sesquistis globulus, sunflower, tobacco, poplar, etc. Among them, rapeseed has become an ideal crop for "production and restoration" of polluted farmland due to its high absorption and low transport of cadmium, high yield, large biomass, fast growth rate and economic output. Among them, restoration rapeseed varieties with low accumulation of heavy metals in rapeseed and super / high accumulation of straw have attracted much attention. However, at this stage, the screening of restoration rapeseed varieties focuses more on safe production, ignoring the efficient production of rapeseed varieties in cadmium-contaminated farmland. Therefore, it is imperative to incorporate the adaptability of rapeseed to cadmium-contaminated farmland into the variety screening and evaluation system.

[0003] However, the current screening methods for cadmium-remediation rapeseed varieties are still imperfect. Screening technologies mostly involve phenotypic traits and gene-level screening. Either the screening indicators are not comprehensive, or the screening operation process is complicated and costly. There is a dilemma that the variety screening is completed but the variety is no longer a mainstream variety, making it difficult to promote. Therefore, there is an urgent need for a rapeseed variety that is easy to operate, has comprehensive indicators and is not costly to strongly adapt to cadmium-contaminated farmland restoration. Summary of the invention

[0004] The inventors found in their research that rapeseed is often used as a preferred crop for alternative planting in cadmium-contaminated farmland due to its high absorption of cadmium in its roots and stems and low accumulation in rapeseed. However, high-quality rapeseed varieties that can both safely produce and repair farmland contaminated by cadmium are rare on the market. Ultimately, an identification method for restoration rapeseed varieties with strong adaptability to cadmium-contaminated farmland has not been established. Therefore, it is necessary to create a method for identifying restoration rapeseed varieties with strong adaptability to cadmium-contaminated farmland in order to solve or improve the problem that there are no high-quality restoration rapeseed varieties available for cadmium-contaminated farmland.

[0005] In order to achieve the above object, the present invention provides the following technical solutions:

[0006] A method for identifying rapeseed varieties with strong adaptability to repair cadmium-contaminated farmland, comprising the following steps:

[0007] Step 1: Screening, collection and cultivation of test varieties; preliminarily screen out a list of test varieties and control varieties from existing rapeseed germplasm resources; plant each test rapeseed variety in a plot in a polluted farmland, and manage the field according to local practices until harvest; record relevant indicators of each rapeseed variety at maturity, which at least include cadmium content in stems, cadmium content in seeds, yield, biomass, plant height, oil content, growth period, number of siliques, number of branches, thousand-grain weight, number of siliques and incidence rate data;

[0008] Step 2: Obtain excellent restoration rapeseed varieties by comprehensively evaluating their adaptability to cadmium-contaminated farmland, cadmium enrichment and transport characteristics, cadmium removal capacity, economic benefits, and absorption of various trace elements beneficial to the human body;

[0009] Among them, the adaptability of rapeseed varieties to cadmium-contaminated farmland was evaluated by the adaptability index AI; the enrichment and transport characteristics of cadmium were evaluated by the stem cadmium bioaccumulation factor BAF. 茎 , cadmium transfer coefficient TF from stem to rapeseed 茎-籽 Evaluation; the cadmium removal capacity is evaluated by the cadmium removal amount; the economic benefits of rapeseed varieties are estimated by yield, oil content, rapeseed oil and rapeseed meal market prices; beneficial trace elements are evaluated by the content of at least four trace elements in rapeseed that are beneficial to the human body;

[0010] Step 3: Select rapeseed varieties that meet the following conditions as restoration rapeseed varieties with strong adaptability to cadmium-contaminated farmland. The screening conditions are: ① Adaptability index AI>1; ② BAF 茎 >1, TF 茎-籽 <1, and the data are better than the control variety; ③ high cadmium removal; ④ high economic benefits; ⑤ the content of at least three trace elements is higher than the control variety.

[0011] Furthermore, the construction process of the adaptability index AI is:

[0012] S1. Calculate the adaptability coefficient AC of each agronomic trait:

[0013] AC i =X i ÷X ck (1);

[0014] In formula (1), X i is the test value of agronomic traits of the tested rapeseed varieties; X ck is the test value of agronomic traits of rapeseed control varieties; i = 1, 2, 3, 4, 5...n;

[0015] S2. The standard definition of adaptability index AI is:

[0016] AC 总 =AC 1+AC 2 +…+AC i …+AC n (2);

[0017]

[0018] To simplify the adaptability evaluation, correlation analysis was conducted on rapeseed yield, biomass, plant height, oil content, growth period, pod number, branch number, 1000-grain weight, seed number per pod, incidence rate, and cadmium content in grains, and four indicators with the highest correlation were selected, namely Indicator A, Indicator B, Indicator C, and Indicator D;

[0019] S3. Construct a simplified adaptability index AI model; taking the adaptability index AI as the dependent variable and the adaptability coefficients of Indicator A, Indicator B, Indicator C, and Indicator D as independent variables, linear regression fitting was performed using SPSS data software to obtain the non-standardized coefficients a, b, c, d, and the constant e; obtain the simplified adaptability index AI of each rapeseed variety for cadmium-polluted farmland,

[0020] AI = a×AC 1 + b×AC 2 + c×AC 3 + d×AC 4 + e (4);

[0021] In formula (4), AC 1 , AC 2 , AC 3 , AC 4 are the adaptability coefficients AC of Indicator A, Indicator B, Indicator C, and Indicator D of the tested rapeseed varieties for cadmium-polluted farmland respectively; AI < 0 indicates weak adaptability, 0 < AI ≤ 1 indicates medium adaptability, and AI > 1 indicates strong adaptability.

[0022] Furthermore, Indicator A, Indicator B, Indicator C, and Indicator D are the growth period, plant height, biomass, and yield respectively, and the non-standardized coefficients a, b, c, d are 0.339, 0.121, 0.301, 0.339 respectively, and the constant e is -0.063; obtain the final calculation formula of the simplified adaptability index AI:

[0023] AI = 0.339×AC 1 +0.121×AC 2 +0.301×AC 3 +0.339×AC 4 -0.063 (5).

[0024] Furthermore, the preliminary screening conditions for the test varieties are: relatively stable agronomic traits, which at least include growth period, plant height, oil content, yield, and biomass; the control variety is Rongyou 18.

[0025] Furthermore, the calculation formula for cadmium removal is:

[0026] Cadmium removal (mg / hectare) = C 籽 ×m 产 +C 茎 ×(m 生 -m 产 ) (6);

[0027] In formula (6), C 籽 is the cadmium concentration in rapeseed (mg / kg), C 茎 is the cadmium concentration in rapeseed stems (mg / kg), m 产 is rapeseed yield (kg / hectare), m 生 Biomass (kg / hectare); biomass is the weight of rapeseed plants 20 to 25 cm above the ground.

[0028] Furthermore, when evaluating the cadmium removal capacity, a cluster analysis was performed on the cadmium removal amount, which was divided into three groups: low removal amount, medium removal amount, and high removal amount.

[0029] Furthermore, when evaluating the economic benefits of rapeseed varieties, the economic benefits of each variety were calculated based on the oil content, rapeseed yield, rapeseed oil and rapeseed meal market prices of the rapeseed variety in the current year; then a cluster analysis was performed on the economic benefits, which were divided into three groups: low economic benefits, medium economic benefits and high economic benefits.

[0030] Furthermore, in step 2, the beneficial trace elements are finally evaluated; the types of beneficial trace elements used for evaluation include manganese, nickel, molybdenum, iron, and zinc.

[0031] The beneficial effects of the present invention are:

[0032] The present invention aims at at least one of the problems that traditional plant restoration of cadmium-contaminated farmland has no economic benefits, the cost of restoration by technologies such as soil conditioners is high, and farmers have low acceptance. It provides a method for identifying rapeseed varieties with strong adaptability to restoration of cadmium-contaminated farmland, and obtains restoration rapeseed varieties by comprehensively evaluating the adaptability of the tested rapeseed varieties to cadmium-contaminated farmland, cadmium absorption and transportation characteristics, economic benefits, cadmium removal capacity, and absorption and accumulation of trace elements beneficial to the human body. Using restoration rapeseed varieties for alternative planting can achieve the dual goals of "safe production and pollution restoration" for cadmium-contaminated farmland; compared with soil passivator restoration technology, there is no need to pay extra for conditioners, rapeseed straw is removed from farmland, and there is no risk of secondary pollution. At the same time, rapeseed is a winter crop and does not compete with summer grain for land, so it can achieve a good harvest of grain and oil and ensure my country's grain and oil security.

[0033] The invention plants test rapeseed varieties in cadmium-contaminated farmland, and compared with traditional methods such as applying soil conditioners, does not require additional economic investment, is an in-situ green restoration technology, and can achieve the dual goals of safe rapeseed production and farmland pollution restoration, with a restoration efficiency comparable to that of Sedum southeasternensis. The identification method of the invention has comprehensive indicators, taking into account the adaptability of rapeseed, the ability to enrich, transport and remove cadmium, economic benefits and trace elements beneficial to the human body, and does not require complex and costly identification methods such as pot experiments, indoor experiments, and gene screening. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] The drawings constituting a part of the present application are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. Among them:

[0035] Figure 1 is a flow chart of an embodiment of the present invention.

[0036] Figure 2 This is the cluster analysis result of the cadmium removal amount of the test rapeseed according to the embodiment of the present invention.

[0037] Figure 3 This is the cluster analysis result of the economic benefits of the tested rapeseed in the embodiment of the present invention.

[0038] Figure 4 This is a heat map of the correlation between cadmium content and agronomic shape of 150 tested rapeseed varieties in the examples of the present invention.

[0039] Figure 5 It is the linear regression fitting result in the embodiment of the present invention.

[0040] Figure 6 This is a list of rapeseed varieties tested in an embodiment of the present invention. DETAILED DESCRIPTION

[0041] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field belong to the scope of protection of the present invention.

[0042] The present invention will be described in detail below with reference to the accompanying drawings and in conjunction with embodiments.

[0043] like Figure 1 As shown, a method for identifying rapeseed varieties with strong adaptability to repair cadmium-contaminated farmland includes the following steps:

[0044] Step 1: Screening, collection and cultivation of test varieties; preliminarily screen out a list of test varieties and control varieties from existing rapeseed germplasm resources; plant each test rapeseed variety in a small plot in a polluted farmland, with each variety repeated in three plots, and perform field management according to local practices until harvest; record relevant indicators of each rapeseed variety at maturity, which at least include cadmium content in stems, cadmium content in seeds, yield, biomass, plant height, oil content, growth period, number of siliques, number of branches, thousand-grain weight, number of siliques and incidence rate data;

[0045] Step 2: Obtain excellent restoration rapeseed varieties by comprehensively evaluating their adaptability to cadmium-contaminated farmland, cadmium enrichment and transport characteristics, cadmium removal capacity, economic benefits, and absorption of various trace elements beneficial to the human body;

[0046] Among them, the adaptability of rapeseed varieties to cadmium-contaminated farmland was evaluated by the adaptability index AI; the enrichment and transport characteristics of cadmium were evaluated by the stem cadmium bioaccumulation factor BAF. 茎 , cadmium transfer coefficient TF from stem to rapeseed 茎-籽 Evaluation; the cadmium removal capacity is evaluated by the cadmium removal amount; the economic benefits of rapeseed varieties are estimated by yield, oil content, rapeseed oil and rapeseed meal market prices; beneficial trace elements are evaluated by the content of at least four trace elements in rapeseed that are beneficial to the human body;

[0047] Step 3: Select rapeseed varieties that meet the following conditions as restoration rapeseed varieties with strong adaptability to cadmium-contaminated farmland. The screening conditions are: ① Adaptability index AI>1; ② BAF 茎 >1, TF 茎-籽 <1, and the data are better than the control variety; ③ high cadmium removal; ④ high economic benefits; ⑤ the content of at least three trace elements is higher than the control variety.

[0048] The construction process of Adaptability Index AI is:

[0049] S1. Calculate the adaptability coefficient AC of each relevant indicator:

[0050] AC i =X i ÷X ck (1);

[0051] In formula (1), X i is the test value of agronomic traits of the tested rapeseed varieties; X ck is the test value of agronomic traits of rapeseed control varieties; i = 1, 2, 3, 4, 5...n;

[0052] S2. The standard definition of adaptability index AI is:

[0053] AC 总 =AC1 +AC 2 +…+AC i …+AC n (2);

[0054]

[0055] The standard formula for the adaptability index AI needs to be calculated based on the test values of all agronomic traits and the adaptability coefficient AC, which is rather cumbersome. To simplify the adaptability evaluation, correlation analysis is performed on rape yield, biomass, plant height, oil content, growth period, silique number, branch number, 1000-grain weight, seeds per silique, incidence rate, and cadmium content in grains, and the four indicators with the highest correlation are selected to calculate the simplified adaptability index AI, namely Indicator A, Indicator B, Indicator C, and Indicator D;

[0056] S3. Construct a simplified adaptability index AI model:

[0057] Taking the adaptability index AI as the dependent variable and the adaptability coefficients of Indicator A, Indicator B, Indicator C, and Indicator D as independent variables, linear regression fitting is performed using SPSS data software to obtain the non-standardized coefficients a, b, c, d, and the constant e; the simplified adaptability index AI of each rape variety for cadmium-polluted farmland is obtained:

[0058] AI = a×AC 1 + b×AC 2 + c×AC 3 + d×AC 4 + e (4);

[0059] In formula (4), AC 1 , AC 2 , AC 3 , AC 4 are the adaptability coefficients AC of Indicator A, Indicator B, Indicator C, and Indicator D of the tested rape varieties for cadmium-polluted farmland, respectively; AI < 0 indicates weak adaptability, 0 < AI ≤ 1 indicates medium adaptability, and AI > 1 indicates strong adaptability.

[0060] In step two, beneficial trace elements are finally evaluated; the beneficial trace elements for evaluation include manganese, nickel, molybdenum, iron, and zinc, avoiding the problem of high economic cost for determining trace elements for all tested varieties.

[0061] Moreover, in the early stage of the present invention, through the rape germplasm resource library or other published rape germplasm resource information, the agronomic traits such as the growth period, plant height, oil content, yield, and biomass of rape varieties are obtained, and the economic benefits of rape varieties are preliminarily estimated, which can narrow the range of tested varieties and reduce the workload of screening tested rape varieties.

[0062] Next, the specific process of the present invention is described in conjunction with specific examples.

[0063] In this example, a rapid screening of rapeseed varieties with strong adaptability to cadmium-contaminated farmland restoration was conducted at the experimental base in Santang Town, Hengnan County, Hengyang City, Hunan Province. Multiple sampling points were taken from the fields for testing, and the total cadmium concentration in the soil of the experimental field was 0.45-0.62 mg / kg, with a pH of 5.45-6.73.

[0064] A method for identifying rapeseed varieties with strong adaptability to repair cadmium-contaminated farmland, comprising the following steps:

[0065] Step 1: Screening, collection and cultivation of test varieties;

[0066] Screening and collection of test varieties: Information on test rapeseed varieties was collected through various channels such as rapeseed planting resource libraries and agricultural research institutes. A preliminary screening was performed on agronomic traits such as yield, biomass, plant height, and growth period. Varieties with relatively stable agronomic traits were selected, and a list of test varieties was obtained after removing varieties with poor agronomic traits. The list of test varieties obtained in this example includes 150 rapeseed varieties (including one control variety), see Figure 6 As shown; Rongyou No. 18 is a control variety, which is commonly used in the national rapeseed industry technology system, and its agronomic traits are relatively stable; the seeds of the participating rapeseed varieties were collected through market purchases and agricultural research institutes in various provinces and cities, and a total of 150 participating rapeseed varieties were collected;

[0067] Cultivation of test varieties: When planting rapeseed, the "high ridge and deep furrow" planting method is adopted. Three experimental plots (plot area 20 square meters) are set up for each variety, the sowing density is 25,000 plants / mu, and field management is carried out according to local habits;

[0068] The rapeseed was tested at maturity, and the cadmium content in the stems, cadmium content in the seeds, yield, biomass, plant height, oil content, growth period, number of siliques, number of branches, 1000-grain weight, number of siliques and incidence rate of 150 rapeseed varieties were measured and recorded according to the national standard method; the biomass was simulated by machine harvesting, and only rapeseed plants above 20 to 25 cm from the ground were collected and weighed; the stem and seed samples of each rapeseed variety were collected, and the samples were pre-treated and acid-digested according to conventional methods, and the cadmium content of the samples was determined by inductively coupled plasma-mass spectrometry (ICP-MS); and the average value of the measurement data of the three plots was calculated.

[0069] Step 2: Obtain excellent restoration rapeseed varieties by comprehensively evaluating their adaptability to cadmium-contaminated farmland, cadmium enrichment and transport characteristics, cadmium removal capacity, economic benefits, and absorption of various trace elements beneficial to the human body;

[0070] Among them, the adaptability of rapeseed varieties to cadmium-contaminated farmland was evaluated by the adaptability index AI; the enrichment and transport characteristics of cadmium were evaluated by the stem cadmium bioaccumulation factor BAF. 茎 , cadmium transfer coefficient TF from stem to rapeseed 茎-籽 Evaluation; the cadmium removal capacity is evaluated by the cadmium removal amount; the economic benefits of rapeseed varieties are estimated by yield, oil content, rapeseed oil and rapeseed meal market prices; beneficial trace elements are evaluated by the content of at least four trace elements in rapeseed that are beneficial to the human body.

[0071] Step 3: Select rapeseed varieties that meet the following conditions as restoration rapeseed varieties with strong adaptability to cadmium-contaminated farmland. The screening conditions are: ① Adaptability index AI>1; ② BAF 茎 >1, TF 茎-籽 <1, and the data is better than the control variety; ③ high cadmium removal; ④ high economic benefits; ⑤ at least three trace elements are higher than the control variety. When evaluating, considering that trace elements beneficial to the human body require experimental detection, which has cost and time and labor costs, the evaluation of this indicator (i.e., ⑤ in the screening conditions) is placed at the end, and only the participating rapeseed varieties that have completed other evaluation indicators and met the requirements of restoration rapeseed varieties (i.e., ①③③④ in the screening conditions) are evaluated for beneficial trace elements;

[0072] In step 2 and step 3, the evaluation process of each indicator is as follows:

[0073] (I) Evaluation of the adaptability index AI requires the establishment of the adaptability index AI formula first. The construction process is as follows:

[0074] Step 1: Correlation analysis is performed on the cadmium content of grains and agronomic traits such as yield, biomass, plant height, oil content, growth period, number of siliques, number of branches, thousand-grain weight, number of siliques, and incidence, and the four indicators with the highest correlation are selected. In this embodiment, the correlation analysis is performed to obtain Figure 4 The correlation heat map shown is from Figure 4 It can be seen that the four indicators with the highest correlation with the cadmium content in grains are growth period, plant height, biomass and yield;

[0075] Step 2, calculation of adaptability coefficient AC: Substitute the test values ​​of agronomic traits such as growth period, plant height, biomass and yield into the calculation formula of adaptability coefficient AC of rapeseed to cadmium-contaminated farmland to obtain the adaptability coefficient AC of each agronomic trait of 150 rapeseed varieties; the adaptability coefficient AC of each agronomic trait is:

[0076] AC i =X i ÷X ck (1);

[0077] In formula (1), X iis the measured value of the agronomic traits of the tested rapeseed varieties; X ck is the measured value of the agronomic traits of the rapeseed control variety; i = 1, 2, 3, 4, 5... n;

[0078] Step 3: Taking the cadmium content adaptability index AI of the seeds as the dependent variable, and the adaptability coefficients of the growth period, plant height, biomass and yield as independent variables respectively, use the SPSS data software for linear regression fitting to obtain the results as shown in Figure 5 , and obtain the unstandardized coefficients a, b, c, d and the constant e;;

[0079] Step 4: Subsequently, substitute the calculated adaptability coefficients AC of the growth period, plant height, biomass and yield into the calculation formula of the cadmium-polluted farmland adaptability index AI of rapeseed (simplified adaptability index AI, formula (4)) to obtain the adaptability index of 150 rapeseed varieties to cadmium-polluted farmland. Obtain the final calculation formula of the simplified adaptability index AI of each rapeseed variety to cadmium-polluted farmland;

[0080] AI = 0.339×AC 1 +0.121×AC 2 +0.301×AC 3 +0.339×AC 4 -0.063 (5);

[0081] In formula (5), AC 1 , AC 2 , AC 3 , AC 4 are the adaptability coefficients AC of the growth period, plant height, biomass and yield of the tested rapeseed varieties to cadmium-polluted farmland respectively; AI < 0 is weak adaptability, 0 < AI ≤ 1 is medium adaptability, and AI > 1 is strong adaptability;

[0082] Rapeseed varieties with strong adaptability to cadmium-polluted farmland (AI > 1) meet the basic requirements of rapeseed varieties for remediation with strong adaptability to cadmium-polluted farmland. Statistical analysis shows that according to the calculation of formula (5), among the 150 tested rapeseed varieties, 66 varieties have an AI value greater than 1.

[0083] Using the final calculation formula of the simplified adaptability index AI in this embodiment (formula (5)), when evaluating the adaptability of rapeseed to cadmium-polluted farmland subsequently, only the four traits of the growth period, plant height, biomass and yield need to be measured to complete the adaptability evaluation, and it is not necessary to measure and calculate all the agronomic traits, and the adaptability evaluation result of rapeseed to cadmium-polluted farmland can be obtained relatively quickly through formula (3).

[0084] (2) Calculate the cadmium bioaccumulation factor (BAF 茎 ) and the cadmium transfer coefficient from stem to seed (TF茎-籽 ), BAF>1, TF<1, and the rapeseed varieties with data better than the control varieties meet the basic requirements of restoration rapeseed varieties. Statistics show that the BAF of the 66 participating rapeseed varieties with adaptability index AI values ​​greater than 1 is 茎 Both are greater than 1, TF 茎-籽 Compared with the control varieties, the BAF values ​​of the 66 tested rapeseed varieties were 茎 Greater than the control variety BAF 茎 , and TF 茎-籽 Smaller than the control variety TF 茎-籽 There are 33 rapeseed varieties, as shown in Table 1:

[0085] Table 1 List of rapeseed varieties with high cadmium absorption and low cadmium transport

[0086] Serial number Variety name <![CDATA[BAF 茎 ]]> <![CDATA[TF 茎-籽 ]]> Serial number Variety name <![CDATA[BAF 茎 ]]> <![CDATA[TF 茎-籽 ]]> 1 HEB06 3.38 0.07 18 H06 2.09 0.06 2 HEA09 3.34 0.08 19 Cinnamon Oil 71 2.81 0.09 3 LZS12 2.33 0.06 20 Xingyou No.2 2.30 0.07 4 HEB01 3.69 0.08 21 HEA05 2.98 0.08 5 HEA10 2.90 0.07 22 17M170 2.60 0.05 6 Huayou 2133 2.35 0.07 23 HEA07 2.29 0.09 7 FY14-20 3.01 0.08 24 HEB11 3.20 0.09 8 Sunshine 972 3.74 0.07 25 HEA11 2.30 0.09 9 HEA04 3.06 0.08 26 Mianbang 2002 2.36 0.08 10 HEB02 2.56 0.08 27 Huayou Miscellaneous 2012 2.43 0.07 11 HEB10 2.79 0.08 28 J115 2.90 0.09 12 Zaoza No. 8 4.65 0.04 29 Yuyou 61 3.61 0.04 13 CPC 967 3.32 0.06 30 C09 in 21 2.84 0.07 14 HEB12 3.32 0.07 31 HEA08 2.64 0.09 15 HEA12 2.54 0.09 32 Huayou Miscellaneous 20201 2.50 0.08 16 HEA06 4.56 0.06 33 Oil 2 3.17 0.04 17 21 in C04 3.13 0.09

[0087] (III) The cadmium removed from the 150 rapeseed varieties when they were removed from the plots was calculated based on the cadmium removal amount calculation formula, and the economic benefits were estimated based on the rapeseed oil content, rapeseed yield, and the market prices of rapeseed oil and rapeseed meal; cluster analysis was performed on the cadmium removal amount and economic benefits of the 150 rapeseed varieties, and the varieties belonging to the high removal amount group and the high economic benefit group met the basic requirements for restoration rapeseed varieties;

[0088] Cadmium removal (mg / hectare) = C 籽 ×m 产 +C 茎 ×(m 生 -m 产 ) (6);

[0089] In formula (6), C 籽 is the cadmium concentration in rapeseed (mg / kg), C 茎 is the cadmium concentration in rapeseed stems (mg / kg), rapeseed yield, m 生 The biomass of rapeseed (kg / hectare) was simulated by machine harvesting, and only rapeseed plants above 20-25 cm above the ground were collected for weighing. Figure 2 , Figure 3 The results of cluster analysis of cadmium removal and economic benefits of the tested rapeseed are shown. The 12 rapeseed varieties clustered into the high removal group are HEA06, HEB06, HEB01, HEA09, Fengyou 509, 21zhong C02, Zhongyou 967, Yangguang 902, HEB12, FY14-20, HEA10, and HEA04; ​​the 6 varieties in the high economic benefit group are HEA06, JB06, JB07, Fengyou 509, Fengyou 845, and Yangguang 972. The only rapeseed varieties that meet both high removal and high economic benefits are HEA06, Fengyou 509, and Yangguang 902.

[0090] (IV) Through comprehensive evaluation of the adaptability of 150 rapeseed varieties to cadmium-contaminated farmland, cadmium enrichment and transport characteristics, cadmium removal capacity and economic benefits, the varieties that meet the characteristics of strong adaptability to cadmium-contaminated farmland, high absorption and low transport, high economic benefits and high cadmium removal are candidate varieties of restoration rapeseed. In this embodiment, there are two rapeseed varieties that can simultaneously meet the requirements of strong adaptability, high enrichment and low transport, high cadmium removal and high economic benefits, namely HEA06 and Sunshine 972. The specific information is shown in Table 2. The BAF stem of the rapeseed variety HEA06 is 4.56, which is 2.2 times that of Rongyou No. 18; the TF stem-seed is only 0.06, far below 1; the cadmium removal capacity is as high as 72.63g / hectare, which is 3.8 times that of the control variety, and the restoration effect is comparable to that of the cadmium hyperaccumulator plant Southeast Sedum; the economic benefit is 1.4 times that of the control variety, which means that farmers planting this variety can not only repair cadmium-contaminated farmland, but also increase their income by about 5,000 yuan per hectare. The BAF of Sunshine 972 茎 is 3.74, 1.8 times that of Rongyou No. 18. 茎-籽 It is only 0.07, and the cadmium removal amount is 52.82g / hectare, which is 2.7 times that of the control variety. The economic benefit is 17,764 yuan / hectare, slightly higher than HEA06.

[0091] Table 2 List of candidate rapeseed varieties with strong adaptability to restoration of cadmium-contaminated farmland

[0092]

[0093] (V) Various trace elements beneficial to the human body, such as nickel, molybdenum, iron, and zinc, in the rapeseed of the candidate varieties of the repair class rapeseed are measured. With reference to the control varieties, the varieties in which the beneficial trace elements in the rapeseed are not reduced are the varieties of the repair class rapeseed with strong adaptability to cadmium-contaminated farmland. In the present embodiment, the various trace elements beneficial to the human body, such as manganese, nickel, molybdenum, iron, and zinc in Table 2 are measured. The overall performance of HEA06 and Sunshine 972 is to remove manganese, and nickel, molybdenum, iron, and zinc all show an upward trend (Table 3). After analysis, the reason for the decline of manganese is that the cadmium element in the rapeseed is transported through the manganese element transport channel, and the two are related to a competitive relationship. One of the characteristics of the repair class rapeseed variety is high absorption of cadmium, so the manganese content will decrease. Compared with the control variety Rongyou No. 18, the absorption of nickel by HEA06 and Sunshine 972 increased by about 10 times, the absorption of molybdenum increased by about 2 times, and the absorption of iron and zinc was also slightly improved. HEA06 and Sunshine 972 are the rape varieties with strong adaptability to cadmium-contaminated farmland restoration that were finally screened out in this embodiment. In other implementations, the element contents of various trace elements (manganese, nickel, molybdenum, iron, zinc, copper, selenium, iodine, chromium, and cobalt) that are beneficial to the human body can be measured.

[0094] Table 3 List of beneficial trace elements in rapeseed (unit: mg / kg)

[0095] Variety name manganese nickel molybdenum iron Zinc Rong oil No. 18 80.48±1.66 2.67±0.07 0.32±0.01 47.53±12.2 36.20±0.96 HEA06 41.25±1.88 25.11±0.72 0.73±0.08 51.37±0.89 38.91±0.67 Sunshine 972 39.69±8.04 25.54±2.06 0.59±0.11 65.37±11.36 42.17±4.30

[0096] The identification method of the present invention has comprehensive indicators, taking into account the adaptability of rapeseed, the ability of cadmium to enrich, transport and remove, economic benefits and trace elements beneficial to the human body, and does not require pot tests, indoor tests, gene screening and other complex and costly identification methods; the optimized simplified adaptability index AI is used to evaluate the adaptability of the participating rapeseed varieties to cadmium-contaminated farmland. Only 4 agronomic shape test values ​​are needed as parameters to obtain the adaptability evaluation results of the participating rapeseed varieties, and there is no need to measure and calculate all agronomic traits. The amount of measurement data and data calculation is small, which is convenient for rapid identification of rapeseed varieties with strong adaptability to cadmium-contaminated farmland restoration.

[0097] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention are within the scope of protection of the pending claims of the present invention.

Claims

1. A method for identifying rapeseed varieties with strong adaptability to repair cadmium-contaminated farmland, characterized in that: It includes the following steps: Step 1: Screening, collecting and cultivating test varieties; initially screening a list of test varieties and control varieties from existing rapeseed germplasm resources; planting each test rapeseed variety in small plots in cadmium-polluted farmland, and conducting field management according to local customs until harvest; recording relevant indicators of each rapeseed variety at maturity, and these relevant indicators at least include cadmium content in stems, cadmium content in grains, yield, biomass, plant height, oil content, growth period, number of pods, number of branches, 1000-grain weight, number of grains per pod and incidence data; Step 2: Obtaining excellent rapeseed varieties for remediation by comprehensively evaluating the adaptability of rapeseed varieties to cadmium-polluted farmland, the characteristics of cadmium enrichment and translocation, the cadmium removal ability, economic benefits, and the absorption of various beneficial trace elements for the human body; Among them, the adaptability of rapeseed varieties to cadmium-contaminated farmland was evaluated by the adaptability index AI; the enrichment and transport characteristics of cadmium were evaluated by the stem cadmium bioaccumulation factor BAF. 茎 , cadmium transfer coefficient TF from stem to rapeseed 茎-籽 Evaluation; the cadmium removal capacity is evaluated by the cadmium removal amount; the economic benefits of rapeseed varieties are estimated by yield, oil content, rapeseed oil and rapeseed meal market prices; beneficial trace elements are evaluated by the content of at least four trace elements in rapeseed that are beneficial to the human body; Step 3: Select rapeseed varieties that meet the following conditions as restoration rapeseed varieties with strong adaptability to cadmium-contaminated farmland. The screening conditions are: ① Adaptability index AI>1; ② BAF 茎 >1, TF 茎-籽 <1, and the data are better than the control variety; ③ high cadmium removal; ④ high economic benefits; ⑤ the content of at least three trace elements is higher than the control variety.

2. The method for identifying rapeseed varieties with strong adaptability to repair cadmium-contaminated farmland according to claim 1, characterized in that: The construction process of the adaptability index AI is as follows: S1. Calculate the adaptability coefficient AC of each agronomic trait: AC i = X i ÷ X ck (1); In formula (1), X i is the test value of agronomic traits of the tested rapeseed varieties; X ck is the test value of agronomic traits of rapeseed control varieties; i = 1, 2, 3, 4, 5...n; S2. The standard formula of the adaptability index AI is defined as: AC 总 =AC1+AC2+…+AC i …+AC n (2); To simplify the adaptability evaluation, correlation analysis is performed on rapeseed yield, biomass, plant height, oil content, growth period, number of pods, number of branches, 1000-grain weight, number of grains per pod, incidence and cadmium content in grains, and the four indicators with the highest correlation are selected, namely indicator A, indicator B, indicator C and indicator D; S3. Construct a simplified adaptability index AI model; use the adaptability index AI as the dependent variable, and the adaptability coefficients of indicator A, indicator B, indicator C and indicator D as independent variables, and use SPSS data software for linear regression fitting to obtain the non-standardized coefficients a, b, c, d and the constant e; obtain the simplified adaptability index AI of each rapeseed variety to cadmium-polluted farmland, AI = a×AC1 + b×AC2 + c×AC3 + d×AC4 + e (4); In formula (4), AC1, AC2, AC3, AC4 are the adaptability coefficients AC of indicator A, indicator B, indicator C and indicator D of the test rapeseed varieties to cadmium-polluted farmland respectively; AI < 0 indicates weak adaptability, 0 < AI ≤ 1 indicates medium adaptability, and AI > 1 indicates strong adaptability.

3. The method for identifying rapeseed varieties with strong adaptability to repair cadmium-contaminated farmland according to claim 2, characterized in that: Indicator A, indicator B, indicator C and indicator D are the growth period, plant height, biomass and yield respectively, and the non-standardized coefficients a, b, c, d are 0.339, 0.121, 0.301, 0.339 respectively, and the constant e is -0.063; obtain the final calculation formula of the simplified adaptability index AI: AI = 0.339×AC1 + 0.121×AC2 + 0.301×AC3 + 0.339×AC4 - 0.063 (5).

4. The method for identifying rapeseed varieties with strong adaptability to repair cadmium-contaminated farmland according to claim 1, characterized in that: The preliminary screening conditions for test varieties are: relatively stable agronomic traits, and these agronomic traits at least include growth period, plant height, oil content, yield, biomass; the control variety is Rongyou 18.

5. The method for identifying rapeseed varieties with strong adaptability to repair cadmium-contaminated farmland according to claim 1, characterized in that: The calculation formula for cadmium removal amount is: Cadmium removal (mg / hectare) = C 籽 ×m 产 +C 茎 ×(m 生 -m 产 )(6); In formula (6), C 籽 is the cadmium concentration in rapeseed (mg / kg), C 茎 is the cadmium concentration in rapeseed stems (mg / kg), m 产 is rapeseed yield (kg / hectare), m 生 Biomass (kg / hectare); biomass is the weight of rapeseed plants 20 to 25 cm above the ground.

6. The method for identifying rapeseed varieties with strong adaptability to repair cadmium-contaminated farmland according to claim 5, characterized in that: When evaluating the cadmium removal ability, cluster analysis is performed on the cadmium removal amount, which is divided into 3 groups: low removal amount, medium removal amount and high removal amount.

7. The method for identifying rapeseed varieties with strong adaptability to repair cadmium-contaminated farmland according to claim 1, characterized in that: When evaluating the economic benefits of rapeseed varieties, the economic benefits of each variety were calculated based on the oil content of the rapeseed variety, rapeseed yield, and the market prices of rapeseed oil and rapeseed meal in the current year. Then, a cluster analysis was performed on the economic benefits, which were divided into three groups: low economic benefit, medium economic benefit, and high economic benefit.

8. The method for identifying rapeseed varieties with strong adaptability to repair cadmium-contaminated farmland according to claim 1, characterized in that: In step two, the beneficial trace elements are finally evaluated; the types of beneficial trace elements used for evaluation include manganese, nickel, molybdenum, iron, and zinc.

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