Rapid identification method and device for corn root nitrogen sensitivity
By isolating and culturing lateral radicles of maize seedlings in high-nitrogen and low-nitrogen nutrient solutions, the problems of inconsistent materials and prolonged time in the evaluation of maize nitrogen sensitivity were solved, and a rapid and accurate assessment of root nitrogen sensitivity was achieved.
Patent Information
- Application Number
- CN202511158409.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-08-19
- Publication Date
- 2025-11-21
AI Technical Summary
Existing methods for evaluating nitrogen sensitivity in maize suffer from differences in nitrogen stored within the kernels and inconsistent germination times, leading to wasted experimental materials, prolonged evaluation time, and increased uncertainty.
Lateral radicles of maize seedlings were cultured separately in high-nitrogen and low-nitrogen nutrient solutions. The nitrogen sensitivity of maize roots was assessed by measuring the difference in root length. The influence of differences in nitrogen stored in the kernels was eliminated using a simple device and formulated nutrient solution.
It improves the accuracy and efficiency of nitrogen sensitivity testing in maize roots, reduces material waste, shortens evaluation time, and provides stable nitrogen sensitivity assessment indicators.
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Figure CN120992852A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of crop performance testing technology, specifically to a rapid identification method and apparatus for nitrogen sensitivity of maize roots. Background Technology
[0002] Maize is one of the world's major food crops, and nitrogen is one of the essential macronutrients for maize growth, development, and final yield. Maize mainly absorbs nitrate nitrogen from the soil through its roots. Detecting and evaluating the sensitivity of target maize genotypes to nitrogen concentration provides technical and theoretical support for elucidating the nitrogen response mechanism of maize and for breeding work.
[0003] However, since corn kernels themselves contain a certain amount of nitrogen, they can compensate for insufficient external nitrogen supply for a period of time after germination, thus delaying the time for nitrogen sensitivity testing. Furthermore, even among corn varieties with the same genotype, the nitrogen content stored in different kernels often varies due to factors such as cultivation methods and environmental changes. It is necessary to select kernels with relatively consistent nitrogen content, size, and weight for testing under different nitrogen treatments. During this process, it is also necessary to observe and exclude kernels that germinated too quickly or too slowly in the early stages. This not only wastes experimental materials and delays the evaluation time but also increases the uncertainty in assessing nitrogen sensitivity.
[0004] Therefore, there is an urgent need in this field to design a method that can quickly identify the nitrogen sensitivity of maize roots. Summary of the Invention
[0005] To address the inconsistencies in individual maize nitrogen sensitivity evaluation methods regarding factors such as grain size, germination time, and growth rate, this invention provides a rapid method and apparatus for identifying nitrogen sensitivity in maize roots. This method involves culturing individual maize embryonic root pairs in nutrient solutions with different nitrogen concentrations and determining the nitrogen sensitivity of maize roots by detecting root length.
[0006] To achieve the above objectives, the present invention provides the following technical solution:
[0007] A rapid method for identifying nitrogen sensitivity in maize roots, comprising the following steps:
[0008] (a) Provide at least one single maize seedling that has germinated and grown at least one pair of lateral radicles;
[0009] (b) Provide high-nitrogen and low-nitrogen nutrient solutions;
[0010] (c) Provide an apparatus comprising two mutually isolated culture zones;
[0011] (d) Add the high-nitrogen nutrient solution to the first culture zone and add the low-nitrogen nutrient solution to the second culture zone;
[0012] (e) The root system of the single maize seedling is isolated and cultured, with at least one lateral radicle placed in the high nitrogen nutrient solution in the first culture area, and another lateral radicle of the same origin placed in the low nitrogen nutrient solution in the second culture area.
[0013] (f) After a preset culture time, the length of the lateral radicle in the high-nitrogen nutrient solution and the low-nitrogen nutrient solution is measured respectively.
[0014] (g) Assess the root nitrogen sensitivity of the maize plant based on the difference between the length of the radicle on the high-nitrogen side and the length of the radicle on the low-nitrogen side.
[0015] In step (a), corn seedlings with lateral radicles of roughly the same length are selected. If seedlings meeting the length requirement cannot be found, the length of the lateral radicles can be pre-measured as the initial length before treatment. The subsequent measured value is then subtracted from the initial length for calculation, thus making the length difference detected after the preset cultivation time more accurate.
[0016] In step (e), the main root of the corn seedling is placed in a low-nitrogen nutrient solution.
[0017] In step (f), the root length is measured and recorded multiple times at different time points after root division culture, and the average value of the length difference is calculated as the final nitrogen sensitivity index.
[0018] Furthermore, it also includes step (h), which involves periodically replacing the high-nitrogen nutrient solution and the low-nitrogen nutrient solution.
[0019] The high-nitrogen nutrient solution formula is as follows: 5 mmol potassium nitrate (KNO3), 5 mmol / L calcium chloride (CaCl2), 2 mmol / L magnesium chloride (MgCl2), 0.05 mmol / L EDTA-Fe-Na Salt, 0.5 mmol / L potassium dihydrogen phosphate (KH2PO4), 50 μmol / L boric acid (H3BO4), 10 μmol / L manganese chloride (MnCl2), 1 μmol / L zinc sulfate (ZnSO4), 0.3 μmol / L copper sulfate (CuSO4), and 0.5 μmol / L sodium molybdate (Na2MoO4).
[0020] The low-nitrogen nutrient solution formula is as follows: 0.2 mmol / L potassium nitrate (KNO3), 4.8 mmol / L potassium chloride (KCl), 5 mmol / L calcium chloride (CaCl2), 2 mmol / L magnesium chloride (MgCl2), 0.05 mmol / L EDTA iron-sodium salt (EDTA-Fe-NaSalt), 0.5 mmol / L potassium dihydrogen phosphate (KH2PO4), 50 μmol / L boric acid (H3BO4), 10 μmol / L manganese chloride (MnCl2), 1 μmol / L zinc sulfate (ZnSO4), 0.3 μmol / L copper sulfate (CuSO4), and 0.5 μmol / L sodium molybdate (Na2MoO4).
[0021] This invention also provides a rapid identification device for nitrogen sensitivity of maize roots, comprising two culture boxes that can independently contain nutrient solutions, the two culture boxes being placed side by side; a high-nitrogen nutrient solution and a low-nitrogen nutrient solution are respectively added to the two culture boxes. The root system of a maize seedling is separated and placed in the two culture boxes respectively.
[0022] Compared with the prior art, the beneficial effects of the present invention are:
[0023] The rapid identification method for nitrogen sensitivity of maize roots in this invention requires simple equipment and readily available materials, does not require professional assembly technology, eliminates the influence of differences in nitrogen storage among maize kernels of the same genotype on the determination of high and low nitrogen sensitivity, improves measurement accuracy, reduces the time to obtain results, saves kernel usage, reduces waste of the tested material, and improves the efficiency of nitrogen sensitivity determination of maize roots. Attached Figure Description
[0024] Figure 1 This is a front view of the rapid identification device for nitrogen sensitivity of maize roots according to the present invention during use;
[0025] Figure 2 This is a top view of the rapid identification device for nitrogen sensitivity of maize roots in this invention during use;
[0026] Figure 3 This is a schematic diagram showing the dimensions of the rapid identification device for nitrogen sensitivity of maize roots according to the present invention.
[0027] Figure 4 The root lengths of B73 and Mo17 under high-nitrogen and low-nitrogen treatments are shown. Detailed Implementation
[0028] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.
[0029] Example 1
[0030] A rapid method for identifying nitrogen sensitivity in maize roots, comprising the following steps:
[0031] (1) Germinate corn kernels on germination paper.
[0032] Select plump corn kernels to be tested, soak the kernels in a 5% sodium hypochlorite solution for 15-20 minutes for disinfection, rinse the kernels repeatedly with purified water 5 times, and spread the washed kernels evenly on germination paper moistened with water for germination.
[0033] (2) Prepare high-nitrogen and low-nitrogen nutrient solutions according to the modified Hoadland formula, and divide them into two hydroponic boxes, filling about 1 / 3 of the boxes.
[0034] The specific recipe is as follows:
[0035] The high-nitrogen nutrient solution formula is as follows: 5 mmol potassium nitrate (KNO3), 5 mmol / L calcium chloride (CaCl2), 2 mmol / L magnesium chloride (MgCl2), 0.05 mmol / L EDTA-Fe-Na Salt, 0.5 mmol / L potassium dihydrogen phosphate (KH2PO4), 50 μmol / L boric acid (H3BO4), 10 μmol / L manganese chloride (MnCl2), 1 μmol / L zinc sulfate (ZnSO4), 0.3 μmol / L copper sulfate (CuSO4), and 0.5 μmol / L sodium molybdate (Na2MoO4).
[0036] The low-nitrogen nutrient solution formula is as follows: 0.2 mmol / L potassium nitrate (KNO3), 4.8 mmol / L potassium chloride (KCl) (potassium chloride is used to supplement potassium ions in the low-nitrogen nutrient solution formula), 5 mmol / L calcium chloride (CaCl2), 2 mmol / L magnesium chloride (MgCl2), 0.05 mmol / L EDTA-Fe-Na Salt, 0.5 mmol / L potassium dihydrogen phosphate (KH2PO4), 50 μmol / L boric acid (H3BO4), 10 μmol / L manganese chloride (MnCl2), 1 μmol / L zinc sulfate (ZnSO4), 0.3 μmol / L copper sulfate (CuSO4), and 0.5 μmol / L sodium molybdate (Na2MoO4).
[0037] (3) Place the new germination paper between the two hydroponic boxes.
[0038] Cut the germination paper to the size that fits the hydroponic box, and stick it to the inside of the high and low nitrogen hydroponic boxes respectively. Place the hydroponic boxes side by side so that the sides with the germination paper are touching.
[0039] (4) Place the seeds that have sprouted a taproot and lateral seminal roots of the same length on the germination paper between the two boxes, and place each pair of lateral seminal roots of the same length on one side of the high-nitrogen and low-nitrogen nutrient solutions respectively.
[0040] In this method, seeds with lateral radicles of uniform length are selected and placed between two boxes. The taproot and one lateral radicle are placed on the low-nitrogen side, and the other lateral radicle is placed on the high-nitrogen side. If there is an odd number of lateral radicles, an additional lateral radicle is placed on the low-nitrogen side.
[0041] Place the cut germination paper on the outside of the germination box relative to the root, ensuring that the root is between the two germination papers, and secure it with nylon netting (place the nylon netting on the outermost side to prevent the seedling from falling off), so that the germination paper absorbs the nutrient solution and keeps the root in the nutrient solution.
[0042] (5) Change the nutrient solution every two days;
[0043] (6) Determine the growth length of the radicle on the high- and low-nitrogen sides.
[0044] The lengths of the radicles on both sides were recorded on the third and sixth days after root division treatment. The length difference between the corresponding radicle pairs on the high-nitrogen and low-nitrogen sides was recorded. A T-test was used to detect whether there was a significant difference in the length of the low-nitrogen and high-nitrogen radicles of the tested genotypes. The length differences measured at different time points were evaluated, and the mean value was taken as the root nitrogen sensitivity index for the corresponding genotype.
[0045] Example 2
[0046] like Figure 1-3 As shown, a rapid identification device for nitrogen sensitivity of maize roots includes two culture boxes (10cm long × 7cm wide × 10cm high) that can independently hold nutrient solution, placed side by side; a high-nitrogen nutrient solution and a low-nitrogen nutrient solution are added to the two culture boxes respectively. The root system of a maize seedling is separated and placed in the two culture boxes respectively.
[0047] Place two culture boxes in an incubator. The incubator has an upper base length of 24cm, a lower base length of 20cm, a width of 16cm, and a height of 16cm.
[0048] Example 3
[0049] The method of Example 1 and the apparatus of Example 2 were used to rapidly identify the nitrogen sensitivity of maize roots of B73 and Mo17.
[0050] The results are as follows Figure 4 As shown, it can be seen that the difference in root growth response to high and low nitrogen levels between the two maize genotypes (B73 and Mo17) can be observed after 3 days of cultivation. Specifically, the radicle of B73 grows faster under low nitrogen conditions compared to the lateral radicle under high nitrogen conditions, while the lateral radicle of Mo17 shows similar growth rates in both nitrogen concentration nutrient solutions (no significant difference). Therefore, it can be concluded that the roots of B73 are more sensitive to external nitrogen concentration. Furthermore, since each pair of radicles in this invention comes from the same plant (hereinafter referred to as radicle pairs), the influence of differences in stored nutrients between different kernels of the same genotype is eliminated. Therefore, the difference in radicle pair lengths can be used to quantitatively evaluate the differences in maize root sensitivity to nitrogen concentration. Figure 4 The results showed that the differences in radicle pairs between B73 and Mo17 were significantly greater at 3 and 6 days after treatment. However, the differences in lateral radicle pairs within the same genotype were not significant at 3 and 6 days after treatment, indicating that the differences in lateral radicle pairs within the same genotype were relatively stable and could be used to quantify the root nitrogen sensitivity of the target genotype. Therefore, the rapid identification method for maize root nitrogen sensitivity of this invention can identify nitrogen-sensitive and insensitive maize plants within 3-6 days, and the sensitivity of maize roots to nitrogen concentration can be quantified by the difference in length between each radicle pair.
[0051] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.
Claims
1. A rapid method for identifying nitrogen sensitivity in maize roots, characterized in that... This includes the following steps: (a) Provide at least one single maize seedling that has germinated and grown at least one pair of lateral radicles; (b) Provide high-nitrogen and low-nitrogen nutrient solutions; (c) Provide an apparatus comprising two mutually isolated culture zones; (d) Add the high-nitrogen nutrient solution to the first culture zone and add the low-nitrogen nutrient solution to the second culture zone; (e) The root system of the single maize seedling is isolated and cultured, with at least one lateral radicle placed in the high nitrogen nutrient solution in the first culture area, and another lateral radicle of the same origin placed in the low nitrogen nutrient solution in the second culture area. (f) After a preset culture time, the length of the lateral radicle in the high-nitrogen nutrient solution and the low-nitrogen nutrient solution is measured respectively. (g) The root nitrogen sensitivity of the maize plant is assessed based on the difference between the lateral radicle length in the high-nitrogen nutrient solution and the lateral radicle length in the low-nitrogen nutrient solution.
2. The rapid identification method for nitrogen sensitivity of maize roots according to claim 1, characterized in that: In step (a), corn seedlings with basically uniform lateral radicle lengths are selected. If seedlings that meet the requirement of uniform length cannot be found, the length of the lateral radicle can be measured in advance before treatment as the initial length, and the subsequent measured value is calculated by subtracting the initial length.
3. The rapid identification method for nitrogen sensitivity of maize roots according to claim 1, characterized in that: In step (e), the taproot of the corn seedling is placed in a low-nitrogen nutrient solution.
4. The rapid identification method for nitrogen sensitivity of maize roots according to claim 1, characterized in that: In step (f), the root length is measured and recorded multiple times at different time points after root division culture, and the average value of the length difference is calculated as the final nitrogen sensitivity index.
5. The rapid identification method for nitrogen sensitivity of maize roots according to claim 1, characterized in that: It also includes step (h), which involves periodically replacing the high-nitrogen nutrient solution and the low-nitrogen nutrient solution.
6. The rapid identification method for nitrogen sensitivity of maize roots according to claim 1, characterized in that: The high-nitrogen nutrient solution formula is as follows: 5 mmol / L potassium nitrate, 5 mmol / L calcium chloride, 2 mmol / L magnesium chloride, 0.05 mmol / L EDTA iron-sodium salt, 0.5 mmol / L potassium dihydrogen phosphate, 50 μmol / L boric acid, 10 μmol / L manganese chloride, 1 μmol L–1 zinc sulfate, 0.3 μmol / L copper sulfate, and 0.5 μmol / L sodium molybdate.
7. The rapid identification method for nitrogen sensitivity of maize roots according to claim 1, characterized in that: The low-nitrogen nutrient solution formula is as follows: 0.2 mmol / L potassium nitrate, 4.8 mmol / L potassium chloride, 5 mmol / L calcium chloride, 2 mmol / L magnesium chloride, 0.05 mmol / L EDTA iron-sodium salt, 0.5 mmol / L potassium dihydrogen phosphate, 50 μmol / L boric acid, 10 μmol / L manganese chloride, 1 μmol / L zinc sulfate, 0.3 μmol / L copper sulfate, and 0.5 μmol / L sodium molybdate.
8. A rapid identification device for nitrogen sensitivity of maize roots using the method described in any one of claims 1-7, characterized in that: It includes two culture boxes that can independently contain nutrient solutions, and the two culture boxes are placed side by side and close together; high-nitrogen nutrient solution and low-nitrogen nutrient solution are added to the two culture boxes respectively.
9. The rapid identification device for nitrogen sensitivity of maize roots according to claim 8, characterized in that: The root system of a corn seedling was separated and placed in the two culture boxes respectively.