A method for screening nitrogen-efficient rice varieties

Abstract

The present invention belongs to the technical field of rice breeding, and discloses a method for screening nitrogen-efficient rice varieties, comprising: planting pretreated rice seeds of different varieties in pretreated planting lands respectively; performing field management of rice, and measuring the yields of rice seeds of different varieties under different nitrogen fertilizer treatments respectively after harvest; calculating the dry weight, nitrogen content, nitrogen absorption index and nitrogen fertilizer absorption and utilization efficiency of mature rice of different varieties; evaluating the nitrogen efficiency of different rice varieties based on the dry weight, nitrogen content, nitrogen absorption index and nitrogen fertilizer absorption and utilization efficiency of mature rice; dividing rice varieties based on the nitrogen efficiency evaluation results combined with the yields of rice under different nitrogen fertilizers; and evaluating the comprehensive excellent index of rice varieties to screen out nitrogen-efficient rice varieties. The present invention fully considers the nitrogen application amount, yield, dry weight and plant nitrogen absorption, and can provide an effective screening method for the screening and cultivation of nitrogen-efficient rice varieties.

Description

Technical Field

[0001] The invention belongs to the technical field of rice breeding, and in particular relates to a method for screening nitrogen-efficient rice varieties. Background Art

[0002] At present, rice (scientific name: Oryza sativa L.) is commonly known as rice, which is an annual aquatic herb of the Poaceae family. The culm is upright, 0.5-1.5 meters high, varying with varieties. The leaf sheath is glabrous and loose; the ligule is lanceolate; the leaf blade is linear-lanceolate, about 1 cm wide, glabrous, and rough. The panicle is large and sparse, with rough edges; the spikelet contains 1 mature flower; the lemma is very small, leaving only a half-moon-shaped mark at the tip of the spikelet stalk, which is cone-shaped; the lemma of the pregnant flowers on both sides is thick, with 5 veins, the midrib is ridged, and there are small square-shaped nipple-like protrusions on the surface, thick papery, covered with fine hairs, and the terminal hairs are dense, with awns or without awns; the palea is homogeneous with the lemma, with 3 veins, the tip is sharp and without beaks; the stamen anther is 2-3 mm long. The caryopsis is about 5 mm long and about 2 mm wide; the embryo ratio is about 1 / 4 of the caryopsis length.

[0003] Nitrogen is an important mineral nutrient element that affects plant growth and development, and is also an important component of chloroplasts, nucleic acids, proteins, and many secondary metabolites. The nitrogen fertilizer utilization rate of rice in my country is 28%-40%, showing a high fertilizer and low efficiency phenomenon. Excessive application of nitrogen fertilizer not only reduces the utilization efficiency of nitrogen, resulting in a huge waste of energy, but also increases the production cost of crops and dampens farmers' enthusiasm for production. Therefore, screening and cultivating new crop varieties that efficiently utilize nitrogen fertilizers is the key to solving the contradiction between environment and resources in my country's agricultural production.

[0004] However, the existing screening methods for nitrogen-efficient rice varieties cannot reasonably, comprehensively and accurately evaluate the nitrogen absorption of rice varieties, and the traits of the screened rice varieties are unstable.

[0005] Through the above analysis, the problems and defects of the existing technology are: the existing screening method for nitrogen-efficient rice varieties cannot reasonably, comprehensively and accurately evaluate the nitrogen absorption of rice varieties, and the traits of the screened rice varieties are unstable. Summary of the invention

[0006] In view of the problems existing in the prior art, the present invention provides a method for screening nitrogen-efficient rice varieties.

[0007] The present invention is achieved by a method for screening nitrogen-efficient rice varieties, the method comprising:

[0008] Step 1: obtaining healthy, disease-free and insect-free seeds of multiple rice varieties, and pre-treating the obtained rice seeds; selecting a plot of land with medium soil fertility as a rice planting site, and pre-treating the planting site;

[0009] Step 2: Planting the pretreated rice seeds of different varieties in the pretreated planting land respectively; performing field management of rice, and measuring the yields of the rice seeds of different varieties under different nitrogen fertilizer treatments after harvest;

[0010] Step 3, calculating the dry weight, nitrogen content, nitrogen absorption index and nitrogen fertilizer absorption and utilization efficiency of different rice varieties after maturity; and evaluating the nitrogen efficiency of different rice varieties based on the dry weight, nitrogen content, nitrogen absorption index and nitrogen fertilizer absorption and utilization efficiency of the rice after maturity;

[0011] Step 4: classify rice varieties based on the nitrogen efficiency evaluation result and the yield of rice under different nitrogen fertilizers; and evaluate the comprehensive excellence index of rice varieties to screen out the nitrogen high-efficiency rice varieties.

[0012] Furthermore, the pre-processing of the obtained rice seeds comprises:

[0013] First, the obtained rice seeds were rinsed with clean water for 1 minute, and then the rinsed rice seeds were dried with a drying device to a moisture content of 16%;

[0014] Secondly, the dried rice seeds are treated with a microwave plasma treatment apparatus, and the microwave-treated rice seeds are soaked in warm water at 25° C.-27° C. for 30 minutes to obtain pretreated rice seeds.

[0015] Further, the pretreatment of the planting site includes:

[0016] First, the surface soil of the planting ground is cleaned and tilled with a rotary tiller, and phosphate fertilizer is applied once in combination with tillage.

[0017] Secondly, the tilled planting land was divided into four parts, and the treatments of no nitrogen fertilizer, low nitrogen fertilizer, normal nitrogen fertilizer and high nitrogen fertilizer were set respectively, and nitrogen fertilizer and potassium fertilizer were applied three times;

[0018] Finally, a split-plot setting was adopted, with fertilizer levels as the main plot and rice varieties as the split plots. The main plots were separated by stalks, and the stalks were covered with plastic film.

[0019] Furthermore, before step 2, the following steps need to be performed:

[0020] Soil samples from the planting sites in each area were collected and processed, and then the pH value, organic matter content, total nitrogen content, total phosphorus content, total potassium, alkaline-hydrolyzed nitrogen, available phosphorus and quick-acting potassium content of the soil in each area were tested.

[0021] Further, the calculation of the dry weight, nitrogen content and nitrogen fertilizer absorption and utilization efficiency of different varieties of rice after maturity includes:

[0022] The harvested rice plants are washed, roots are removed, and the rice plants are dried in a dryer, and the dry weight is measured to obtain the dry weight of the rice.

[0023] The nitrogen content of the rice plants was measured by using the semi-micro Kjeldahl method after drying.

[0024] The nitrogen fertilizer absorption and utilization efficiency was calculated using the following formula:

[0025]

[0026] Among them, Q0 represents the nitrogen application amount in kg / mu, Q1 and Q2 represent the nitrogen absorption amount of the plants under nitrogen, phosphorus and potassium treatments and the nitrogen absorption amount of the plants under phosphorus and potassium treatments in kg / mu respectively; the nitrogen absorption amount of the plants = dry weight at maturity * nitrogen content.

[0027] Further, the calculation of nitrogen absorption index of different varieties of rice after maturity includes:

[0028] Mature seeds of various rice varieties were obtained, and germination and seedling tests were carried out on mature seeds of all rice varieties under the same nitrogen level. The dry weight of total biomass was measured at the three-leaf and one-heart seedling stage, and compared one-to-one with the dry weight of total biomass of the same variety of rice in the control group under a nitrogen-free environment, and the nitrogen absorption index of each test variety was calculated respectively; the nitrogen absorption index is the percentage ratio of the dry weight of total biomass under a nitrogen environment to that under a nitrogen-free environment.

[0029] Furthermore, the classification of rice varieties includes:

[0030] Rice varieties are divided into high nitrogen and high yield, low nitrogen and high yield, high nitrogen and low yield, and low nitrogen and low yield.

[0031] Furthermore, the classification of rice varieties also includes:

[0032] When the nitrogen absorption index of the rice variety to be classified is greater than 50% and the nitrogen fertilizer absorption and utilization efficiency and nitrogen content of the rice variety to be classified are significantly higher than those of the rice variety planted without nitrogen fertilizer, the rice variety to be classified is judged to be a high-nitrogen variety.

[0033] Furthermore, the evaluation of the comprehensive quality index of rice varieties includes:

[0034] The rice yield, quality, effective tiller number, nitrogen absorption index, dry matter weight, nitrogen content, and nitrogen fertilizer absorption and utilization efficiency were used as rice evaluation indicators;

[0035] According to the entropy weight analysis method, the weight coefficients of yield, quality, effective tillering number, nitrogen absorption index, dry matter weight, nitrogen content, and nitrogen fertilizer absorption and utilization efficiency were calculated;

[0036] Constructing a rice efficacy coefficient matrix based on the rice evaluation index and the weight coefficient of each index, and calculating the comprehensive excellent index value of rice efficacy;

[0037] According to the value of the comprehensive excellent index of rice efficacy, the comprehensive characteristics of each rice variety are evaluated, and nitrogen-efficient rice varieties are screened out.

[0038] Furthermore, the weight coefficients of the nitrogen absorption index, dry matter weight, nitrogen content, and nitrogen fertilizer absorption and utilization efficiency are greater than the weight coefficients of yield, quality, and effective tillering number.

[0039] In combination with the above technical solutions and the technical problems solved, please analyze the advantages and positive effects of the technical solutions to be protected by the present invention from the following aspects:

[0040] First, in view of the technical problems existing in the above-mentioned prior art and the difficulty of solving the problems, the technical solutions to be protected by the present invention and the results and data during the research and development process are closely combined to analyze in detail and deeply how the technical solutions of the present invention solve the technical problems, and some creative technical effects brought about after solving the problems. The specific description is as follows:

[0041] The present invention plants and screens different rice varieties with the participation of different nitrogen fertilizers, and evaluates the nitrogen efficiency of rice in combination with the dry weight of mature rice plants, the nitrogen absorption index and the nitrogen fertilizer absorption efficiency, so that the evaluation result is not only accurate but also relatively objective and comprehensive; at the same time, the comprehensive evaluation and screening of rice varieties are carried out based on the yield and nitrogen efficiency parameters combined with the rice efficacy evaluation matrix, so that rice varieties with high nitrogen efficiency and high yield that can be stably inherited can be screened.

[0042] Second, considering the technical solution as a whole or from the perspective of the product, the technical effects and advantages of the technical solution to be protected by the present invention are described in detail as follows:

[0043] The invention fully considers the nitrogen application amount, yield, dry matter weight and nitrogen absorption amount of the plant, and can provide an effective screening method for the screening and cultivation of nitrogen-efficient rice varieties. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] Figure 1 is a flow chart of a method for screening nitrogen-efficient rice varieties provided by an embodiment of the present invention;

[0045] Figure 2 is a flow chart of a method for pre-processing obtained rice seeds provided by an embodiment of the present invention;

[0046] Figure 3 It is a flow chart of a method for pre-treating a planting site provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0047] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0048] like Figure 1 As shown, the method for screening nitrogen-efficient rice varieties provided in the embodiment of the present invention comprises:

[0049] S101, obtaining healthy, disease-free and insect-free seeds of multiple rice varieties, and pre-treating the obtained rice seeds; selecting a plot of land with medium soil fertility as a rice planting site, and pre-treating the planting site;

[0050] S102, planting the pretreated rice seeds of different varieties in the pretreated planting land respectively; performing field management of rice, and measuring the yields of the rice seeds of different varieties under different nitrogen fertilizer treatments after harvest;

[0051] S103, and calculating the dry weight, nitrogen content, nitrogen absorption index and nitrogen fertilizer absorption and utilization efficiency of the different varieties of rice after maturity; and evaluating the nitrogen efficiency of the different rice varieties based on the dry weight, nitrogen content, nitrogen absorption index and nitrogen fertilizer absorption and utilization efficiency of the rice after maturity;

[0052] S104, classifying rice varieties based on the nitrogen efficiency evaluation result and the yield of rice under different nitrogen fertilizers; and evaluating the comprehensive excellent index of rice varieties to screen out the nitrogen high-efficiency rice varieties.

[0053] like Figure 2 As shown, the pretreatment of the obtained rice seeds provided in the embodiment of the present invention includes:

[0054] S201, washing the obtained rice seeds with clean water for 1 minute, and then drying the washed rice seeds with a drying device to a moisture content of 16%;

[0055] S202, treating the dried rice seeds using a microwave plasma treatment apparatus, and soaking the microwave-treated rice seeds in warm water at 25° C.-27° C. for 30 minutes to obtain pretreated rice seeds.

[0056] like Figure 3 As shown, the pretreatment of the planting site provided by the embodiment of the present invention includes:

[0057] S301, removing impurities from the surface soil of the planting ground, plowing the soil with a rotary tiller, and applying phosphorus fertilizer once in combination with the plowing;

[0058] S302, dividing the tilled planting land into four equal parts, setting no nitrogen fertilizer application, low nitrogen application, normal nitrogen application and high nitrogen application treatment respectively, and applying nitrogen fertilizer and potassium fertilizer three times;

[0059] S303 adopts split-zone setting, with fertilizer level as the main zone and rice variety as the split zone. The main zone is separated by stems, and the stems are covered with plastic film.

[0060] Before step S102 provided in the embodiment of the present invention, the following steps need to be performed:

[0061] Soil samples from the planting sites in each area were collected and processed, and then the pH value, organic matter content, total nitrogen content, total phosphorus content, total potassium, alkaline-hydrolyzed nitrogen, available phosphorus and quick-acting potassium content of the soil in each area were tested.

[0062] The method for calculating the dry weight, nitrogen content and nitrogen fertilizer absorption and utilization efficiency of different varieties of rice after maturity provided by the embodiment of the present invention includes:

[0063] The harvested rice plants are washed, roots are removed, and the rice plants are dried in a drying machine. The dry weight is measured to obtain the dry weight of the rice.

[0064] The nitrogen content of the rice plants was measured by using the semi-micro Kjeldahl method after drying.

[0065] The nitrogen fertilizer absorption and utilization efficiency was calculated using the following formula:

[0066]

[0067] Among them, Q0 represents the nitrogen application amount in kg / mu, Q1 and Q2 represent the nitrogen absorption amount of the plants under nitrogen, phosphorus and potassium treatments and the nitrogen absorption amount of the plants under phosphorus and potassium treatments in kg / mu respectively; the nitrogen absorption amount of the plants = dry weight at maturity * nitrogen content.

[0068] The method for calculating the nitrogen absorption index of different varieties of rice after maturity provided in an embodiment of the present invention includes:

[0069] Mature seeds of various rice varieties were obtained, and germination and seedling tests were carried out on mature seeds of all rice varieties under the same nitrogen level. The dry weight of total biomass was measured at the three-leaf and one-heart seedling stage, and compared one-to-one with the dry weight of total biomass of the same variety of rice in the control group under a nitrogen-free environment, and the nitrogen absorption index of each test variety was calculated respectively; the nitrogen absorption index is the percentage ratio of the dry weight of total biomass under a nitrogen environment to that under a nitrogen-free environment.

[0070] The classification of rice varieties provided in the embodiment of the present invention includes: classifying rice varieties into high nitrogen and high yield, low nitrogen and high yield, high nitrogen and low yield, and low nitrogen and low yield.

[0071] The rice variety classification provided by the embodiment of the present invention further includes:

[0072] When the nitrogen absorption index of the rice variety to be classified is greater than 50% and the nitrogen fertilizer absorption and utilization efficiency and nitrogen content of the rice variety to be classified are significantly higher than those of the rice variety planted without nitrogen fertilizer, the rice variety to be classified is judged to be a high-nitrogen variety.

[0073] The evaluation of the comprehensive quality index of rice varieties provided in the embodiment of the present invention includes:

[0074] The rice yield, quality, effective tiller number, nitrogen absorption index, dry matter weight, nitrogen content, and nitrogen fertilizer absorption and utilization efficiency were used as rice evaluation indicators;

[0075] According to the entropy weight analysis method, the weight coefficients of yield, quality, effective tillering number, nitrogen absorption index, dry matter weight, nitrogen content, and nitrogen fertilizer absorption and utilization efficiency were calculated;

[0076] Constructing a rice efficacy coefficient matrix based on the rice evaluation index and the weight coefficient of each index, and calculating the comprehensive excellent index value of rice efficacy;

[0077] According to the value of the comprehensive excellent index of rice efficacy, the comprehensive characteristics of each rice variety are evaluated, and nitrogen-efficient rice varieties are screened out.

[0078] The weight coefficients of the nitrogen absorption index, dry matter weight, nitrogen content, and nitrogen fertilizer absorption and utilization efficiency provided by the embodiments of the present invention are greater than the weight coefficients of yield, quality, and effective tillering number.

[0079] The calculation method of the entropy weight analysis method provided by the embodiment of the present invention is as follows: Assuming that m evaluation objects and n evaluation indicators are given, the original data matrix X of each evaluation indicator is established. ij} m×n (i=1,2,3,..., m;j=1,2,3,...,n), press Calculate the standardized data and determine the standardized data P = {p ij} m×n (i=1,2,3,...,m;j=1,2,3,...,n), according to Calculate the information entropy of the evaluation index according to Calculate the weight coefficient of each indicator.

[0080] The method for establishing the efficacy coefficient matrix provided by the embodiment of the present invention is as follows: or Calculate the coefficient value bij of each index membership function to determine the efficacy coefficient matrix B = {b ij} m×n(i=1,2,3,...,m;j=1,2,3,...,n), and then according to Calculate the comprehensive excellent index value of efficacy.

[0081] It should be noted that the embodiments of the present invention can be implemented by hardware, software, or a combination of software and hardware. The hardware part can be implemented using dedicated logic; the software part can be stored in a memory and executed by an appropriate instruction execution system, such as a microprocessor or dedicated design hardware. It can be understood by a person of ordinary skill in the art that the above-mentioned devices and methods can be implemented using computer executable instructions and / or contained in a processor control code, such as a carrier medium such as a disk, CD or DVD-ROM, a programmable memory such as a read-only memory (firmware), or a data carrier such as an optical or electronic signal carrier. Such code is provided on the carrier medium. The device and its modules of the present invention can be implemented by hardware circuits such as very large-scale integrated circuits or gate arrays, semiconductors such as logic chips, transistors, etc., or programmable hardware devices such as field programmable gate arrays, programmable logic devices, etc., can also be implemented by software executed by various types of processors, and can also be implemented by a combination of the above-mentioned hardware circuits and software, such as firmware.

[0082] The above description is only a specific implementation mode of the present invention, but the protection scope of the present invention is not limited thereto. Any modifications, equivalent substitutions and improvements made by any technician familiar with the technical field within the technical scope disclosed by the present invention and within the spirit and principle of the present invention should be covered by the protection scope of the present invention.

Claims

1. A method for screening nitrogen-efficient rice varieties, characterized in that: The method for screening nitrogen-efficient rice varieties comprises: Step 1: obtaining healthy, disease-free and insect-free seeds of multiple rice varieties, and pre-treating the obtained rice seeds; selecting a plot of land with medium soil fertility as a rice planting site, and pre-treating the planting site; Step 2: Planting the pretreated rice seeds of different varieties in the pretreated planting land respectively; performing field management of rice, and measuring the yields of the rice seeds of different varieties under different nitrogen fertilizer treatments after harvest; Step 3, calculating the dry weight, nitrogen content, nitrogen absorption index and nitrogen fertilizer absorption and utilization efficiency of different rice varieties after maturity; and evaluating the nitrogen efficiency of different rice varieties based on the dry weight, nitrogen content, nitrogen absorption index and nitrogen fertilizer absorption and utilization efficiency of the rice after maturity; Step 4: classifying rice varieties based on the nitrogen efficiency evaluation results and the yields of rice under different nitrogen fertilizers; and evaluating the comprehensive excellent index of rice varieties to screen out the nitrogen high-efficiency rice varieties; The obtained rice seeds are pre-treated including: First, the obtained rice seeds were rinsed with clean water for 1 minute, and then the rinsed rice seeds were dried with a drying device to a moisture content of 16%; Secondly, the dried rice seeds are treated with a microwave plasma treatment apparatus, and the microwave-treated rice seeds are soaked in warm water at 25° C. to 27° C. for 30 minutes to obtain pretreated rice seeds; The pretreatment of the planting site comprises: First, the surface soil of the planting ground is cleaned and tilled with a rotary tiller, and phosphate fertilizer is applied once in combination with tillage. Secondly, the tilled planting land was divided into four parts, and the treatments of no nitrogen fertilizer, low nitrogen fertilizer, normal nitrogen fertilizer and high nitrogen fertilizer were set respectively, and nitrogen fertilizer and potassium fertilizer were applied three times; Finally, a split-plot setting was adopted, with fertilizer levels as the main plot and rice varieties as the split plots, with the main plots separated by stems and plastic film used to cover the stems; Before step 2, the following steps must be performed: Collecting soil samples from planting sites in various regions, and after processing the planting site samples, testing the pH value, organic matter content, total nitrogen content, total phosphorus content, total potassium, alkaline nitrogen, available phosphorus and available potassium content of the soil in various regions; The calculation of the dry weight, nitrogen content and nitrogen fertilizer absorption and utilization efficiency of different varieties of rice after maturity includes: The harvested rice plants are washed, roots are removed, and the rice plants are dried in a drying machine. The dry weight is measured to obtain the dry weight of the rice. The nitrogen content of the rice plants was measured by using the semi-micro Kjeldahl method after drying. The nitrogen fertilizer absorption and utilization efficiency was calculated using the following formula: Wherein, Q0 represents the nitrogen application amount kg / mu, Q1 and Q2 represent the nitrogen absorption amount of the plant under the treatment of nitrogen, phosphorus and potassium and the nitrogen absorption amount of the plant under the treatment of phosphorus and potassium respectively. The nitrogen absorption amount of the plant = dry weight at maturity * nitrogen content; The calculation of nitrogen absorption index of different varieties of rice after maturity comprises: Obtain mature seeds of various rice varieties, and conduct germination and seedling tests on mature seeds of all rice varieties at the same nitrogen level, measure the dry weight of total biomass at the three-leaf and one-heart seedling stage, and compare the dry weight of total biomass of rice of the same variety in the control group under a nitrogen-free environment one by one, and calculate the nitrogen absorption index of each test variety; the nitrogen absorption index is the percentage ratio of the dry weight of total biomass under a nitrogen environment to that under a nitrogen-free environment; The rice varieties are divided into: Rice varieties are divided into high nitrogen and high yield, low nitrogen and high yield, high nitrogen and low yield, and low nitrogen and low yield; The rice varieties are divided into: When the nitrogen absorption index of the rice variety to be classified is greater than 50% and the nitrogen fertilizer absorption and utilization efficiency and nitrogen content of the rice variety to be classified are significantly higher than those of the rice variety planted without nitrogen fertilizer, the rice variety to be classified is judged to be a high-nitrogen variety; The evaluation of the comprehensive quality index of rice varieties includes: The rice yield, quality, effective tiller number, nitrogen absorption index, dry matter weight, nitrogen content, and nitrogen fertilizer absorption and utilization efficiency were used as rice evaluation indicators; According to the entropy weight analysis method, the weight coefficients of yield, quality, effective tillering number, nitrogen absorption index, dry matter weight, nitrogen content, and nitrogen fertilizer absorption and utilization efficiency were calculated; Constructing a rice efficacy coefficient matrix based on the rice evaluation index and the weight coefficient of each index, and calculating the comprehensive excellent index value of rice efficacy; According to the value of the comprehensive excellent index of rice efficacy, the comprehensive characteristics of each rice variety are evaluated, and nitrogen-efficient rice varieties are screened out; The weight coefficients of the nitrogen absorption index, dry matter weight, nitrogen content, and nitrogen fertilizer absorption and utilization efficiency are greater than the weight coefficients of yield, quality, and effective tillering number.

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