Method for identifying resistance of rice imidazolinone herbicides

Abstract

The invention discloses a method for identifying the resistance of rice imidazolinone herbicides. The method comprises the following steps: dividing rice varieties into a treatment group and a control group; treating the treated group with imidazolinone herbicides, not treating the control group, respectively recording agronomic characters of the treated group and the control group, and calculating the difference value of the agronomic characters of the treated group and the control group; after the treatment group is treated by the imidazolone herbicides, evaluating the rice allelopathy intensity of the treatment group and the control group, and calculating the allelopathy intensity difference value; and rating the imidazolone herbicide resistance of each rice variety. According to the method, rice seeds are divided into a treatment group and a control group, the treatment group is treated by imidazolone herbicides, and the growth and allelopathy performance of rice treated by the imidazolone herbicides is obtained by combining agronomic trait observation and allelopathy strength evaluation. The resistance of the rice varieties to the imidazolone herbicides can be known more accurately.

Description

Technical Field

[0001] The invention relates to the technical field of rice, and in particular to a method for identifying resistance of rice to imidazolinone herbicides. Background Art

[0002] In modern agricultural production, imidazolinone herbicides, especially imazamox, are favored due to their excellent selectivity, wide spectrum of weed control, low dosage and environmental friendliness. This type of herbicide is mainly absorbed by the stems, leaves and roots of plants, then transmitted in the xylem and phloem, and finally accumulated in the meristem, causing plant death by inhibiting growth.

[0003] Allelopathy is an important phenomenon in ecology, in which plants release specific chemicals to affect the growth of surrounding plants. In rice cultivation, allelopathy has become a potential natural weed control mechanism. Different rice genotypes show significant differences in allelopathic potential, and this potential can be passed on to future generations through genetics.

[0004] However, the herbicide resistance of rice is not only determined by the herbicide resistance gene, but also affected by the allelopathic effect of the rice variety itself. Rice varieties with stronger allelopathic effects can effectively inhibit the growth of weeds and pests, thereby enhancing their resistance potential to herbicides. On the contrary, rice varieties with weaker allelopathic effects, even if they have herbicide resistance genes, may reduce their herbicide resistance potential because they cannot effectively inhibit the growth of weeds.

[0005] In the process of rice variety breeding, allelopathic differences have become an important factor that cannot be ignored. In order to breed better quality and more herbicide-resistant rice varieties, the impact of allelopathic effects on herbicide resistance potential must be fully considered.

[0006] Therefore, it is necessary to provide a method for identifying resistance to imidazolinone herbicides in rice to solve the above technical problems. Summary of the invention

[0007] The invention overcomes the shortcomings of the prior art and provides a method for identifying resistance to imidazolinone herbicides in rice.

[0008] To achieve the above object, the technical solution adopted by the present invention is: a method for identifying resistance to imidazolinone herbicides in rice, comprising the following steps:

[0009] S1. Prepare rice varieties and divide them into treatment group and control group;

[0010] S2. The treatment group was treated with imidazolinone herbicides, while the control group was not treated with imidazolinone herbicides. The agronomic traits of the treatment group and the control group were recorded respectively, and the difference in agronomic traits between the treatment group and the control group was calculated.

[0011] S3. After the treatment group is treated with the imidazolinone herbicide, the allelopathic intensity of rice is evaluated for the treatment group and the control group, and the difference value of the allelopathic intensity between the treatment group and the control group is calculated;

[0012] S4. Rating the resistance of each rice variety to imidazolinone herbicides based on the difference values ​​of agronomic traits and allelopathic intensity.

[0013] In a preferred embodiment of the present invention, in S1, the number of seeds and the germination rate of each rice variety are consistent, and the number of seeds and the germination rate of the treatment group and the control group in the same rice variety are consistent.

[0014] In a preferred embodiment of the present invention, in S2, the treatment group is treated with an imidazolinone herbicide, specifically: when the rice grows to the 3-leaf 1-heart stage, the treatment group is sprayed with the imidazolinone herbicide.

[0015] In a preferred embodiment of the present invention, the spraying treatment is to dilute the imidazolinone herbicide 5% imidazolinone aqueous solution 1000 times and spray the solution on the stems and leaves of rice.

[0016] In a preferred embodiment of the present invention, in S2, after the treated group and the control group are both mature, their agronomic traits are measured and recorded, and the agronomic traits include: plant height, leaf color and yield.

[0017] In a preferred embodiment of the present invention, the leaf color is subdivided into different levels based on the yellowing degree of the leaves, and a corresponding numerical value is assigned to each level.

[0018] In a preferred embodiment of the present invention, in said S3, the method for evaluating the intensity of allelopathic effect of rice specifically comprises the following steps:

[0019] S31. Within two weeks after the treatment group is treated with the imidazolinone herbicide, the rice root secretions of the treatment group and the control group are collected, the rice root secretions are separated and purified to obtain allelopathic substances, and the allelopathic substance solutions are prepared;

[0020] S32, soaking weed seeds in a culture medium containing an allelopathic substance solution, and recording the germination rate of the weed seeds;

[0021] S33, planting the germinated weed seedlings in a culture medium containing an allelopathic substance solution, and regularly measuring and recording the plant height of the weed seedlings;

[0022] S34. According to the results recorded in steps S32 and S33, the difference value of the allelopathic intensity between the treatment group and the control group is calculated.

[0023] In a preferred embodiment of the present invention, in said S34, the calculation of the allelopathic intensity difference value between the treatment group and the control group is specifically as follows: Among them G t is the germination rate of the treatment group, G c is the germination rate of the control group, H t is the height of weed seedlings in the treatment group, H c The height of weed seedlings in the control group.

[0024] In a preferred embodiment of the present invention, in S4, the resistance of rice to imidazolinone herbicides is divided into different resistance levels, including: high resistance, medium resistance, low resistance and no resistance.

[0025] In a preferred embodiment of the present invention, in S4, the resistance of rice to imidazolinone herbicides is divided into different resistance levels, specifically, a high resistance evaluation score ≥4.0, a medium resistance evaluation score 3.0≤S<4.0, a low resistance evaluation score 1.0≤S<3.0 and a no resistance evaluation score<1.0.

[0026] In a preferred embodiment of the present invention, in said S5, the resistance of rice varieties to imidazolinone herbicides is rated, which specifically comprises the following steps:

[0027] S41, dividing each agronomic trait change value by the corresponding agronomic trait of the control group to obtain the proportion of each agronomic trait change value;

[0028] S42, setting a variation coefficient, each variation coefficient corresponding to a range of percentages of a variation value of an agronomic trait or allelopathic intensity;

[0029] S43, calculating the evaluation score by weighted average based on all the variation coefficients of the rice varieties obtained in step S42;

[0030] S44. The resistance levels to imidazolinone herbicides are divided into corresponding evaluation score intervals, and the rice varieties are divided into corresponding resistance levels according to the evaluation scores.

[0031] In a preferred embodiment of the present invention, in S43, a weight w is first assigned to each agronomic trait and allelopathic intensity difference value I. i , the weight reflects the importance of each index in the identification of imidazolinone herbicide resistance. Specifically, the weights of plant height (H), leaf color (L) and yield (Y), as well as the allelopathic intensity difference value I are w H 、w L 、w Y and w I , and w H +w L +w Y +w I=1, then the evaluation score S = w H ×c H +w L ×c L +w Y ×c Y +w I ×c I , where c H 、c L 、c Y and c I are the coefficients of variation of the difference values ​​of plant height, leaf color, yield and allelopathic intensity, respectively.

[0032] The present invention solves the defects existing in the background technology and has the following beneficial effects:

[0033] (1) The present invention provides a method for identifying resistance to imidazolinone herbicides in rice, which can be used for screening and identifying rice germplasm resistant to imidazolinone herbicides. Rice seeds are divided into a treatment group and a control group, and the treatment group is treated with imidazolinone herbicides. The growth and allelopathic performance of rice after treatment with imidazolinone herbicides are obtained by combining agronomic trait observation and allelopathic intensity assessment, which helps to more accurately understand the resistance of rice varieties to imidazolinone herbicides. Compared with the prior art, the present invention provides a new idea and method for herbicide resistance identification by integrating agronomic trait observation and allelopathic intensity assessment, which not only enriches the existing identification technical means, but also provides a useful reference and reference for related research.

[0034] (2) In the present invention, imidazolinone herbicides are applied to the soil of the transplanting area of ​​the treatment group once 3-6 months in advance, and the dosage is preferably 500-1000 mL / hm 2 , or directly use a fixed area as the transplanting area for the treatment group, which can ensure that a certain amount of imidazolinone herbicides remain in the soil before transplanting, simulating the residual herbicides of the season to evaluate its potential long-term impact on rice growth. The soil of the control group needs to ensure that it has not been sprayed with imidazolinone herbicides in various ways within a year, and the soil of the treatment group and the control group should be taken from the same area to ensure the consistency of soil components except imidazolinone herbicides, and reduce the noise of rice imidazolinone herbicide resistance identification.

[0035] (3) When identifying the resistance of rice varieties to imidazolinone herbicides, the present invention measures the allelopathic intensity of the treatment group and the control group respectively, calculates the inhibition rate of the rice root secretions of the treatment group and the control group on weed seeds, and then evaluates the effect of imidazolinone herbicides on the allelopathic effect of rice, which provides an important scientific basis for the identification of the resistance of rice varieties to imidazolinone herbicides.

[0036] (4) The present invention quantifies the effect of the allelopathic substances of rice treated with imidazolinone herbicides by comparing the performance of the treatment group and the control group, which is actually manifested as the difference in the inhibitory effect on weed seed germination and seedling growth. The difference value I of the allelopathic effect intensity between the treatment group and the control group is calculated through the above steps, and the change of the allelopathic effect of rice treated with imidazolinone herbicides can be obtained, and then the inhibitory effect of rice on the growth of surrounding weeds after being treated with imidazolinone herbicides can be evaluated, so as to comprehensively evaluate the resistance of rice varieties to imidazolinone herbicides. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art are briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative work.

[0038] Figure 1 The present invention is a flow chart of a method for identifying resistance to imidazolinone herbicides in rice according to a preferred embodiment of the present invention. DETAILED DESCRIPTION

[0039] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0040] In the following description, many specific details are set forth to facilitate a full understanding of the present invention, but the present invention may also be implemented in other ways different from those described herein. Therefore, the protection scope of the present invention is not limited to the specific embodiments disclosed below.

[0041] like Figure 1 As shown, the present invention provides a method for identifying resistance to imidazolinone herbicides in rice, comprising the following steps:

[0042] S1. Prepare rice varieties and divide them into treatment group and control group.

[0043] S2. The treatment group was treated with imidazolinone herbicides, while the control group was not. The agronomic traits of the treatment group and the control group were recorded respectively, and the difference in agronomic traits between the treatment group and the control group was calculated.

[0044] S3. After the treatment group was treated with imidazolinone herbicides, the allelopathic intensity of rice was evaluated for the treatment group and the control group, and the difference in allelopathic intensity between the treatment group and the control group was calculated.

[0045] S4. Rating the resistance of each rice variety to imidazolinone herbicides based on the difference values ​​of agronomic traits and allelopathic intensity.

[0046] The present invention provides a method for identifying resistance to imidazolinone herbicides in rice, which can be used for screening and identifying rice germplasm resistant to imidazolinone herbicides. Rice seeds are divided into a treatment group and a control group, and the treatment group is treated with imidazolinone herbicides. The growth and allelopathic performance of rice after being treated with imidazolinone herbicides are obtained by combining agronomic trait observation and allelopathic intensity evaluation, which helps to more accurately understand the resistance of rice varieties to imidazolinone herbicides. Compared with the prior art, the present invention provides a new idea and method for identifying herbicide resistance by integrating agronomic trait observation and allelopathic evaluation, which not only enriches the existing identification technical means, but also provides a useful reference and reference for related research.

[0047] In step S1, the number of seeds and the germination rate of each rice variety are consistent, and the number of seeds and the germination rate of the treatment group and the control group of the same rice variety are consistent, ensuring that the number of rice seed samples in the treatment group and the control group is consistent.

[0048] Furthermore, the rice seeds in the treatment group and the control group were soaked and germinated, and then sown in a 60 cm×30 cm×3.5 cm seedling tray. The seedling tray was marked to distinguish the treatment group and the control group, and placed under the same growth environment conditions.

[0049] In step S2, the treatment group is treated with an imidazolinone herbicide, specifically: when the rice grows to the 3-leaf 1-heart stage, the treatment group is sprayed with an imidazolinone herbicide. When the rice seedlings grow to 3 leaves 1 heart, that is, when there are already 3 fully expanded leaves on the seedlings, and the 4th leaf begins to grow but has not yet expanded, the rice seedlings at this stage already have a certain resistance and their adaptability to the external environment has also been enhanced. Therefore, choosing this period to use an imidazolinone herbicide can ensure the weeding effect while reducing damage to the crops themselves.

[0050] Further spraying treatment is to dilute the imidazolinone herbicide 5% imidazolinone aqueous solution 1000 times and spray it on the rice stems and leaves. The preferred dosage is 1500mL / hm 2Choose appropriate weather and time for spraying, avoid spraying in high temperature, strong wind or rainy days, ensure the efficacy of the drug and reduce the drift of the drug solution, ensure that the drug solution is evenly sprayed on the stems and leaves of rice seedlings, and reduce errors caused by uneven spraying due to human operation, which affects the results of rice imidazolinone herbicide resistance identification.

[0051] Furthermore, two weeks after the rice seedlings in the treatment group were sprayed, the rice seedlings in the treatment group and the control group were transplanted separately, with a plot area of ​​10m 2 When transplanting, single seedlings are planted, with a row spacing of 20cm-25cm and a plant spacing of 12cm-15cm. There is a 50cm-80cm gap between every three rows to facilitate subsequent observation of the growth of rice.

[0052] It is worth noting that the soil in the transplanting area of ​​the treatment group was treated with imidazolinone herbicides once 3-6 months in advance, and the dosage was preferably 500-1000mL / hm 2 , or directly use a fixed area as the transplanting area for the treatment group, which can ensure that a certain amount of imidazolinone herbicides remain in the soil before transplanting, simulating the residual herbicides of the season to evaluate its potential long-term impact on rice growth. The soil of the control group needs to ensure that it has not been sprayed with imidazolinone herbicides in various ways within a year, and the soil of the treatment group and the control group should be taken from the same area to ensure the consistency of soil components except imidazolinone herbicides, and reduce the noise of rice imidazolinone herbicide resistance identification.

[0053] In step S2, after the treated group and the control group are both mature, their agronomic traits are measured and recorded, and the agronomic traits include: plant height, leaf color and yield.

[0054] Plant height is a direct reflection of the growth status of rice and can directly show the overall growth trend of rice plants. The mechanism of action of imidazolinone herbicides such as imidazolinone includes blocking the action of acetohydroxyacid synthase, affecting the biosynthesis of amino acids, thereby destroying proteins and inhibiting the growth of weeds (including rice). Therefore, by measuring plant height, it is possible to preliminarily determine whether rice is inhibited by herbicides.

[0055] Leaf color is a direct reflection of the chlorophyll content in rice leaves, and chlorophyll is a key substance for photosynthesis in plants. Imidazolinone herbicides may affect the metabolic process of rice, resulting in the obstruction of chlorophyll synthesis or accelerated degradation, thereby changing leaf color. Therefore, leaf color changes can be used as an important indicator of the physiological effects of herbicides on rice.

[0056] Yield is the ultimate goal of rice cultivation and a direct reflection of economic benefits. The impact of imidazolinone herbicides on rice growth will ultimately be reflected in yield. If the herbicide severely inhibits or damages rice growth, it will lead to a decrease in yield. Therefore, by measuring yield, the impact of herbicides on rice growth and economic output can be fully evaluated.

[0057] In the present invention, the performance of three agronomic traits of rice, namely plant height, leaf color and yield, is selected to express the effect of imidazolinone herbicides on rice growth.

[0058] Furthermore, leaf color is subdivided into different levels based on the degree of yellowing of the leaves, and each level is assigned a corresponding value, specifically: Level 0 (normal leaf color, uniform green, no obvious changes), Level 1 (the leaves maintain their natural green, with only slight yellow spots or changes, indicating that the leaf color is minimally affected), Level 2 (the leaf color is light yellow, with more obvious yellow spots or areas, but the overall green still dominates, reflecting that the leaf color is slightly affected), Level 3 (moderate yellow covers most of the leaves, and the green is significantly reduced, indicating that the leaf color is moderately affected), Level 4 (most of the leaves turn dark yellow, and the green area is significantly reduced, indicating that the leaf color is severely affected) and Level 5 (the leaves are almost completely turned into yellow or withered yellow, and the green is almost invisible, indicating that the leaf color is severely affected).

[0059] Furthermore, each leaf color grade was assigned a value as shown in Table 1, reflecting the severity of its impact by imidazolinone herbicides, thereby providing an intuitive and quantitative reference for evaluating the resistance of rice to imidazolinone herbicides.

[0060] Table 1. Leaf color grade assignment table

[0061] grade 0 1 2 3 4 5 Assignment 10 8 6 4 2 0

[0062] In step S2, the difference values ​​of agronomic traits between the treatment group and the control group include: plant height, leaf color and yield of the control group minus the treatment group, indicating the changes in agronomic traits of the same rice variety after being treated with imidazolinone herbicides.

[0063] In step S3, the method for evaluating the intensity of rice allelopathic effect specifically comprises the following steps:

[0064] S31. Within two weeks after the treatment group was treated with the imidazolinone herbicide, the rice root exudates of the treatment group and the control group were collected respectively, the rice root exudates were separated and purified to obtain allelopathic substances, and the allelopathic substance solutions were prepared.

[0065] S32. Soak the weed seeds in a culture medium containing an allelopathic substance solution and record the germination rate of the weed seeds.

[0066] S33. Plant the germinated weed seedlings in a culture medium containing an allelopathic substance solution, and regularly measure and record the plant height of the weed seedlings.

[0067] S34. According to the results recorded in steps S32 and S33, the difference value of the allelopathic intensity between the treatment group and the control group is calculated.

[0068] When the resistance of rice varieties to imidazolinone herbicides is identified, the allelopathic intensity of the treatment group and the control group is measured respectively, and the inhibition rate of the rice root secretions of the treatment group and the control group on weed seeds is calculated to indicate the allelopathic intensity of the treatment group and the control group, and then the influence of the imidazolinone herbicide on the allelopathic effect of rice is evaluated, thereby providing an important scientific basis for the resistance identification of rice varieties to imidazolinone herbicides.

[0069] In step S31, the collection of rice root exudates specifically includes the following steps:

[0070] S311. After 2 hours of morning light exposure, the seedlings of the treatment group and the control group were taken out from the seedling tray, and the roots of the rice seedlings were gently washed with sterile deionized water to remove soil particles and other impurities attached to the root surface.

[0071] S312, placing the washed rice seedling roots in 200 ml of sterile deionized water, allowing the roots to secrete for 12 hours under natural conditions, and obtaining a root washing solution, ensuring that sufficient root secretions are collected in the root washing solution.

[0072] S313, filtering the root washing liquid with a 0.45 um microporous filter membrane to remove solid particles and microorganisms therein to obtain root exudates, and collecting the root exudates in a 150 mm plate, freezing the root exudates with liquid nitrogen, and drying and concentrating the frozen root exudates with a vibrating freeze dryer to obtain allelopathic substances.

[0073] S314, adding the allelopathic substance into water to prepare an allelopathic substance solution.

[0074] Through the above steps, allelopathic substances are separated and purified from the root exudates of rice in the treatment group and the control group, and are prepared into allelopathic substance solutions for subsequent analysis.

[0075] In step S32, the concentration of the allelopathic substance solution is in the range of 0.1 mM to 1.0 mM. Further, multiple concentration gradients can be set to explore the allelopathic effect intensity at different concentrations.

[0076] Furthermore, soaking at least 20 weed seeds in each culture medium, and selecting local common weed species that are sensitive to allelopathic effects, such as barnyard grass and foxtail grass, can more accurately reflect the actual effect of rice allelopathic substances. The germination rate of weed seeds is counted within 7 to 14 days after soaking. Further, germination experiments of multiple groups of weed seeds are conducted, the germination rate is counted at the same time, and the average value is calculated, which more accurately reflects the inhibitory effect of rice allelopathic substances on weed seeds.

[0077] In step S33, allelopathic substance solutions of the same concentration are added to the culture medium, and weed seedlings with good germination and uniform growth are selected from step S32 for transplantation, and the number of transplanted weed seedlings in the culture medium is ensured to be the same. A growth experiment lasting 20 to 30 days is carried out. At the end of the experiment, the plant height of each weed seedling is accurately measured using a ruler or measuring instrument, and the corresponding data is recorded to calculate the average plant height of the weed seedlings in the culture medium.

[0078] The calculation of the allelopathic intensity difference value between the treatment group and the control group in step S34 is specifically as follows: Among them G t is the germination rate of the treatment group, G c is the germination rate of the control group, H t is the average height of weed seedlings in the treatment group, H c The average height of weed seedlings in the control group.

[0079] The above steps are calculated by It represents the ratio of germination rate of the treatment group to that of the control group, reflecting the effect of imidazolinone herbicide treatment on weed seed germination. The germination rate of the treated group is lower than that of the control group, that is, the reduction ratio of the germination rate. It represents the ratio of the average plant height of the treatment group to the average plant height of the control group, reflecting the effect of imidazolinone herbicide treatment on the growth of weed seedlings. The average plant height of the treated group is lower than that of the control group, that is, the reduction ratio of the average plant height. The calculation formula generally represents the difference in the intensity of allelopathic effect between the treated group and the control group, specifically the difference in the inhibitory effect of rice allelopathic substances on weed seed germination and seedling growth caused by the treatment of imidazolinone herbicides.

[0080] The performance of the treatment group and the control group are compared through the above steps, and the influence of the allelopathic substances of rice treated with imidazolinone herbicides is quantified, which is actually manifested as the difference in the inhibitory effect on weed seed germination and seedling growth. The difference value I of the allelopathic effect intensity between the treatment group and the control group is calculated through the above steps, and the change of the allelopathic effect of rice treated with imidazolinone herbicides can be obtained, and then the inhibitory effect of rice on the growth of surrounding weeds after being treated with imidazolinone herbicides can be evaluated, so as to comprehensively evaluate the resistance of rice varieties to imidazolinone herbicides.

[0081] In step S4, the resistance of rice to imidazolinone herbicides is divided into different resistance levels, including: high resistance, medium resistance, low resistance and no resistance.

[0082] In step S4, the resistance of rice varieties to imidazolinone herbicides is rated, which specifically includes the following steps:

[0083] S41. Divide each agronomic trait change value by the corresponding agronomic trait of the control group to obtain the proportion of each agronomic trait change value; wherein the leaf color change is calculated using the leaf color grade assignment.

[0084] S42. Setting a variation coefficient, each variation coefficient corresponds to a range of percentages of a change value of an agronomic trait or allelopathic intensity.

[0085] S43. Calculate the evaluation score by weighted average based on all the variation coefficients of the rice varieties obtained in step S42.

[0086] S44. The resistance levels to imidazolinone herbicides are divided into corresponding evaluation score intervals, and the rice varieties are divided into corresponding resistance levels according to the evaluation scores.

[0087] In step S42, the variation coefficient is specifically set as follows: a positive number indicates an improvement relative to the control group, and a negative number indicates a decrease relative to the control group.

[0088] Plant height: -10% to -6% (-3), -6% to -3% (-2), -3% to 0 (-1), 0 to 3% (1), 3% to 6% (2), 6% to 10% (3). Compared with the control group, the increase or decrease exceeded 10%, and the corresponding coefficient of variation was 4 / -4.

[0089] Leaf color: -100%~-50% (-3), -50%~-20% (-2), -20%~0 (-1), 0~20% (1), 20%~50% (2), 50%~100% (3).

[0090] Yield: -10% to -6% (-3), -6% to -3% (-2), -3% to 0 (-1), 0 to 3% (1), 3% to 6% (2), 6% to 10% (3), increased or decreased by more than 10% relative to the control group, and the corresponding coefficient of variation is 4 / -4.

[0091] The difference value of allelopathic intensity I: -10%~-6%(-3), -6%~-3%(-2), -3%~0(-1), 0~3%(1), 3%~6%(2), 6%~10%(3), which is increased or decreased by more than 10% compared with the control group, and the corresponding coefficient of variation is 4 / -4.

[0092] By setting the coefficient of variation, the changes in agronomic traits and allelopathic intensity are quantified while maintaining consistency and comparability, thereby comprehensively evaluating the resistance of rice varieties to imidazolinone herbicides.

[0093] In step S43, firstly, a weight w is assigned to each agronomic trait and allelopathic intensity difference value I. i , the weight reflects the importance of each index in the identification of imidazolinone herbicide resistance. Specifically, the weights of plant height (H), leaf color (L) and yield (Y), as well as the allelopathic intensity difference value I are w H 、w L 、w Y and w I , and w H +w L +w Y +w I =1, then the evaluation score S = w H ×c H +w L ×c L +w Y ×c Y +w I ×c I , where c H 、c L 、c Y and c I are the coefficients of variation of the difference values ​​of plant height, leaf color, yield and allelopathic intensity, respectively.

[0094] Based on a method for identifying rice resistance to imidazolinone herbicides, a resistance identification experiment was designed to identify the resistance of six rice varieties, namely, Huruanyu No. 1, Zhefengnuo No. 188, Yingxiang No. 1, Shangnongjing No. 927, Shangnongjing No. 219 and Guangmingnuo No. 6, to imidazolinone herbicides.

[0095] Experimental steps: First, ensure that the number of seeds of each variety is consistent and that the number of seeds in the treatment group and the control group is equal; soak the seeds for germination; sow the seeds in seedling trays, mark them and place them in the same growth environment; spray the treatment group with herbicides when the rice grows to the 3-leaf 1-heart stage; two weeks after spraying, transplant the seedlings of the treatment group and the control group into the plot respectively; record plant height, leaf color and yield after maturity; collect root secretions to evaluate the effects on weed seed germination and seedling growth.

[0096] The test varieties were arranged in completely randomized blocks, repeated three times, with a plot area of ​​0.2 mu and harvested in the whole area. Field management was slightly higher than the local field production level. Experimental management should include timely fertilization, pest control, intertillage and weeding, and no use of various plant growth regulators. Ensure that the management measures of various varieties and blocks in the same pilot are consistent (including sowing date, density, fertilizer amount and method, etc.), and the same management measures in the same repetition should be completed on the same day. During the experiment, effective protective measures should be taken in time to prevent and control the harm of people, rats, birds, livestock, poultry, etc. to the experiment.

[0097] The data summary table of the agronomic trait change values ​​and allelopathic intensity difference values ​​I of the above experimental rice varieties is shown in Table 2.

[0098] Table 2. Data summary table

[0099]

[0100]

[0101] According to prior experience, weights are assigned to each indicator and the evaluation score S = 0.265 × c is calculated. H +0.225×c L +0.330×c Y +0.18×c I , the evaluation scores are calculated as shown in Table 3:

[0102] Table 3. Resistance evaluation table

[0103]

[0104] Among them, the resistance of rice to imidazolinone herbicides is divided into different resistance levels, specifically, high resistance evaluation score ≥4.0, medium resistance evaluation score 3.0≤S<4.0, low resistance evaluation score 1.0≤S<3.0 and no resistance evaluation score <1.0.

[0105] The above is based on the ideal embodiment of the present invention. Through the above description, relevant personnel can make various changes and modifications without departing from the technical concept of the present invention. The technical scope of the present invention is not limited to the content in the specification, and the technical scope must be determined according to the scope of the claims.

Claims

1. A method for identifying resistance to imidazolinone herbicides in rice, characterized in that: The following steps are involved: S1. Prepare rice varieties and divide them into treatment group and control group; S2. The treatment group was treated with imidazolinone herbicides, while the control group was not treated with imidazolinone herbicides. The agronomic traits of the treatment group and the control group were recorded respectively, and the difference in agronomic traits between the treatment group and the control group was calculated. S3. After the treatment group is treated with the imidazolinone herbicide, the allelopathic intensity of rice is evaluated for the treatment group and the control group, and the difference value of the allelopathic intensity between the treatment group and the control group is calculated; S4. Rating the resistance of each rice variety to imidazolinone herbicides based on the difference values ​​of agronomic traits and allelopathic intensity.

2. A method for identifying resistance to imidazolinone herbicides in rice according to claim 1, characterized in that: In S1, the number of seeds and the germination rate of each rice variety are consistent, and the number of seeds and the germination rate of the treatment group and the control group in the same rice variety are consistent.

3. The method for identifying resistance to imidazolinone herbicides in rice according to claim 1, characterized in that: In S2, the treatment group is treated with an imidazolinone herbicide, specifically: when the rice grows to the 3-leaf 1-heart stage, the treatment group is sprayed with the imidazolinone herbicide.

4. A method for identifying resistance to imidazolinone herbicides in rice according to claim 3, characterized in that: The spraying treatment is to dilute the imidazolinone herbicide 5% imidazolinone aqueous solution 1000 times and spray it on the rice stems and leaves.

5. The method for identifying resistance to imidazolinone herbicides in rice according to claim 1, characterized in that: In S2, after the treated group and the control group are both mature, their agronomic traits are measured and recorded, and the agronomic traits include: plant height, leaf color and yield.

6. A method for identifying resistance to imidazolinone herbicides in rice according to claim 5, characterized in that: The leaf color is subdivided into different levels based on the degree of yellowing of the leaves, and a corresponding numerical value is assigned to each level.

7. The method for identifying resistance to imidazolinone herbicides in rice according to claim 1, characterized in that: In S3, the method for evaluating the intensity of rice allelopathic effect specifically comprises the following steps: S31. Within two weeks after the treatment group is treated with the imidazolinone herbicide, the rice root secretions of the treatment group and the control group are collected, the rice root secretions are separated and purified to obtain allelopathic substances, and the allelopathic substance solutions are prepared; S32, soaking weed seeds in a culture medium containing an allelopathic substance solution, and recording the germination rate of the weed seeds; S33, planting the germinated weed seedlings in a culture medium containing an allelopathic substance solution, and regularly measuring and recording the plant height of the weed seedlings; S34. According to the results recorded in steps S32 and S33, the difference value of the allelopathic intensity between the treatment group and the control group is calculated.

8. A method for identifying resistance to imidazolinone herbicides in rice according to claim 7, characterized in that: In the above S34, the calculation of the difference value of allelopathic effect intensity between the treatment group and the control group is as follows: Among them G t is the germination rate of the treatment group, G c is the germination rate of the control group, H t is the height of weed seedlings in the treatment group, H c The height of weed seedlings in the control group.

9. A method for identifying resistance to imidazolinone herbicides in rice according to claim 1, characterized in that: In the S4, the resistance of rice to imidazolinone herbicides is divided into different resistance levels, including: high resistance, medium resistance, low resistance and no resistance.

10. A method for identifying resistance to imidazolinone herbicides in rice according to claim 9, characterized in that: In S4, the resistance of rice varieties to imidazolinone herbicides is rated, which specifically includes the following steps: S41, dividing each agronomic trait change value by the corresponding agronomic trait of the control group to obtain the proportion of each agronomic trait change value; S42, setting a variation coefficient, each variation coefficient corresponding to a range of percentages of a variation value of an agronomic trait or allelopathic intensity; S43, calculating the evaluation score by weighted average based on all the variation coefficients of the rice varieties obtained in step S42; S44. The resistance levels to imidazolinone herbicides are divided into corresponding evaluation score intervals, and the rice varieties are divided into corresponding resistance levels according to the evaluation scores.

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