Industrial hemp waterlogging tolerance comprehensive evaluation method based on entropy evaluation method and application of industrial hemp waterlogging tolerance comprehensive evaluation method

Abstract

The invention relates to the technical field of industrial hemp waterlogging tolerance comprehensive evaluation methods, in particular to an industrial hemp waterlogging tolerance comprehensive evaluation method based on an entropy evaluation method and application of the industrial hemp waterlogging tolerance comprehensive evaluation method. On the ninth day of waterlogging stress treatment, measuring morphological indexes and physiological indexes of the industrial cannabis sativa, calculating waterlogging tolerance coefficients of the indexes according to measurement results, and performing correlation analysis to screen core indexes; performing data standardization processing on the screened core indexes, and analyzing and calculating the weight of each index by using an entropy method; finally, according to the calculated index weight, a comprehensive score is calculated, waterlogging tolerance evaluation is carried out, a standardized method is provided for waterlogging disaster stress treatment through the double-sleeve basin method, and the repeatability of the experiment is ensured. The introduction of the waterlogging-resistant coefficient enables different indexes to have comparability, a foundation is laid for subsequent analysis, the step of screening the core indexes through correlation analysis effectively reduces the data dimension, and information redundancy is avoided.

Description

Technical Field

[0001] The invention relates to the technical field of methods for comprehensive evaluation of waterlogging resistance of industrial hemp, in particular to a method for comprehensive evaluation of waterlogging resistance of industrial hemp based on an entropy value method and application thereof. Background Art

[0002] Waterlogging is one of the main environmental factors affecting global agricultural productivity and poses a serious threat to crop production safety. The essence of waterlogging damage to plants is that excessive water hinders the gas exchange between plants and the atmosphere, causing the surrounding oxygen concentration to be too low to form a hypoxic or anaerobic state, resulting in hypoxia in the waterlogged plant tissues, and increased accumulation of carbon dioxide and ethylene, which hinders plant growth and reduces crop yields.

[0003] Cannabis, also known as hemp and fire hemp, belongs to the genus Cannabis of the family Cannabaceae and is a dioecious annual herb. Industrial hemp is a type of cannabis variety that does not have direct drug value. The mass fraction of the hallucinogenic component tetrahydrocannabinol (THC) in its plants is less than 0.3%. At present, industrial hemp is widely grown in Canada, the United States, Europe, Africa, and Asian countries. It is a multi-purpose, sustainable, low-environmental-impact crop that is widely used in many fields, such as textiles, clothing, food, feed, cosmetics, construction, paper, and pharmaceutical industries. Cannabis is mainly suitable for sandy soil and loam environments in temperate monsoon climate zones and subtropical monsoon climate zones. Although it requires sufficient water to achieve high yields, industrial hemp is drought-resistant but not water-resistant.

[0004] In recent years, with the global warming, glacier melting and the frequent occurrence of extreme weather, as well as the concentrated precipitation in the rainy season, the occurrence of heavy rain, rainstorm and continuous heavy rainfall has seriously affected the growth and development of industrial hemp. Most industrial hemp varieties are not resistant to waterlogging, and are susceptible to waterlogging during the process of growth and development, resulting in problems such as decreased yield and reduced quality. The impact of waterlogging on industrial hemp is mainly manifested in growth and development, physiological metabolism and stress resistance. Many scholars have focused on the research on industrial hemp stress resistance, such as drought resistance, salt stress, temperature stress, etc., while there are fewer reports on the research on industrial hemp waterlogging resistance, especially methods related to the comprehensive evaluation of industrial hemp waterlogging resistance. At present, most evaluation methods mainly use principal component analysis and membership function method, and the process is relatively complicated and cumbersome. The present invention calculates the waterlogging resistance coefficient, and uses the correlation coefficient to determine the core index, reduces the number of evaluation indicators, and then uses the entropy weight method to establish a scientific and reliable method for the comprehensive evaluation of industrial hemp waterlogging resistance, so as to screen industrial hemp waterlogging resistance germplasm resources. Summary of the invention

[0005] In view of the deficiencies in the prior art, the present invention provides a method for comprehensive evaluation of waterlogging resistance of industrial hemp based on waterlogging resistance coefficient, correlation coefficient and entropy method and its application, which solves the problem that most evaluation methods proposed in the above-mentioned background technology are complicated and single. The present invention combines morphological indicators and physiological indicators and calculates waterlogging resistance coefficient and correlation coefficient, then screens core indicators, reduces the number of evaluation indicators, and then uses the entropy method to analyze and calculate the weight of each indicator and the comprehensive score of each variety, so as to achieve a comprehensive evaluation of the waterlogging resistance of each variety of industrial hemp. The entropy method used in the present invention is a method commonly used in multi-index decision analysis, and its calculation principle is based on information entropy theory. This method can quantify the importance of different indicators and apply them to fields such as evaluation and ranking, which can improve the efficiency and accuracy of identifying the waterlogging resistance of industrial hemp materials, and provide an objective and reliable method for identifying the strength of industrial hemp waterlogging resistance.

[0006] The present invention proposes a method for comprehensive evaluation of waterlogging resistance of industrial hemp based on entropy method. 1. The method for comprehensive evaluation of waterlogging resistance of industrial hemp based on entropy method is characterized by comprising the following steps:

[0007] First, industrial hemp materials were prepared and cultivated. When the plants grew to a height of about 70 cm in the rapid growth period, the double-pot method was used for waterlogging stress treatment, in which the perforated flower pots for planting industrial hemp were placed in flower pots without holes at the bottom. Water was replenished regularly every day to make the soil water content supersaturated, and the water level was kept 3 cm above the surface of the substrate soil;

[0008] Then, on the 9th day after waterlogging stress treatment, the morphological and physiological indices of industrial hemp were measured, wherein the morphological indices included plant height, stem diameter, aboveground dry weight and underground dry weight, and the physiological indices included chlorophyll a content, chlorophyll b content, total chlorophyll content, carotenoid content, superoxide dismutase SOD activity, peroxidase POD activity, malondialdehyde MDA content, proline content, soluble protein content, soluble sugar content, relative conductivity and root activity;

[0009] Next, the waterlogging resistance coefficient of each indicator was calculated based on the measurement results, and correlation analysis was performed to screen the core indicators;

[0010] Subsequently, the data of the selected core indicators were standardized, and the entropy method was used to analyze and calculate the weight of each indicator;

[0011] Finally, based on the calculated indicator weights, the comprehensive score was calculated and the waterlogging resistance was evaluated.

[0012] Preferably, the calculation formula of the waterlogging resistance coefficient β is:

[0013] β = measured value of waterlogging stress treatment group / measured value of control group

[0014] Among them, the control group was the normal water treatment group. The closer the β value was to 1, the less the index was affected by waterlogging and the stronger the waterlogging resistance was.

[0015] Preferably, the correlation analysis adopts a correlation coefficient heat map method, by calculating the correlation coefficients between the indicators, and selecting the physiological indicators with the greatest correlation with the morphological indicators as the core indicators, specifically including:

[0016] Calculate the correlation coefficient between plant height and other indicators, and select the physiological indicator with the largest absolute value of the correlation coefficient;

[0017] Calculate the correlation coefficient between stem diameter and other indicators, and select the physiological indicator with the largest absolute value of the correlation coefficient;

[0018] Calculate the correlation coefficient between aboveground dry weight and other indicators, and select the physiological indicator with the largest absolute value of the correlation coefficient;

[0019] Calculate the correlation coefficient between underground dry weight and other indicators, and select the physiological indicator with the largest absolute value of the correlation coefficient.

[0020] Preferably, the data standardization process adopts the following formula:

[0021] Positive indicators:

[0022] Contrarian Indicators:

[0023] Among them, X is the original value of the indicator, X min is the minimum value of the indicator, X max It is the maximum value of the indicator; the larger the positive index value, the better the indicator is, and the smaller the reverse index value, the better the indicator is.

[0024] Preferably, the entropy analysis comprises the following steps:

[0025] First, calculate the proportion P of the i-th sample value under the j-th indicator to the total value of the indicator ij :

[0026]

[0027] Among them, X ij is the standardized value of the i-th sample under the j-th indicator;

[0028] Then, calculate the information entropy e of each indicator j :

[0029]

[0030] in, n is the number of samples;

[0031] Next, calculate the information utility value d of each indicator j :

[0032] d j =1-e j

[0033] Finally, calculate the weight coefficient W of each indicator j :

[0034]

[0035] Preferably, the comprehensive score is calculated as follows:

[0036] Multiply the waterlogging resistance coefficient of each indicator by the corresponding weight coefficient, and then add them up to get the final comprehensive score. The higher the comprehensive score, the stronger the waterlogging resistance of the industrial hemp material.

[0037] Preferably, the method for determining the morphological index comprises:

[0038] Use a tape measure to measure the height of the cannabis stalk starting at the base and ending at the tip;

[0039] The diameter of the main stem at 3 cm above the soil surface was measured using a vernier caliper as the stem diameter;

[0040] The aboveground parts of the plants were baked at 60°C for 72 h and then weighed to obtain the aboveground dry weight;

[0041] The roots of the plants were washed and baked at 60°C for 72 h, and then weighed to obtain the dry weight of the underground part.

[0042] Preferably, the method for measuring the physiological index comprises:

[0043] The ethanol extraction method was used to determine the contents of chlorophyll a, chlorophyll b, total chlorophyll and carotenoids; the nitroblue tetrazolium NBT photoreduction method was used to determine the SOD activity; the guaiacol colorimetric method was used to determine the PO D activity; the thiobarbituric acid TBA colorimetric method was used to determine the MDA content; the acid ninhydrin method was used to determine the proline content; the Coomassie brilliant blue method was used to determine the soluble protein content; the anthrone colorimetric method was used to determine the soluble sugar content; the immersion method was used to determine the relative conductivity; and the TTC method was used to determine the root activity.

[0044] Preferably, the industrial hemp material includes different varieties of industrial hemp, and by evaluating the waterlogging resistance of different varieties, industrial hemp varieties with stronger waterlogging resistance can be screened out.

[0045] The method is applied in industrial hemp breeding, and by evaluating the waterlogging resistance of different industrial hemp varieties or breeding materials, varieties or individuals with strong waterlogging resistance are screened out for further breeding work.

[0046] The beneficial effects of the present invention are mainly reflected in the following aspects:

[0047] The method of the present invention cleverly combines multiple innovative points to form a systematic and efficient evaluation system. The double-pot method provides a standardized method for waterlogging stress treatment and ensures the repeatability of the experiment. The introduction of the waterlogging resistance coefficient makes different indicators comparable, laying the foundation for subsequent analysis. The step of correlation analysis to screen core indicators effectively reduces the data dimension and avoids information redundancy. The application of the entropy method solves the objectivity problem of determining the indicator weights. There is a close logical relationship and synergy between these steps, which together constitute a complete and reliable evaluation system.

[0048] Different from the evaluation methods of other crops, the present invention is based on the waterlogging resistance coefficient and the correlation coefficient, and uses the entropy method to conduct a comprehensive evaluation of the waterlogging resistance of industrial hemp germplasm resources: first, the growth physiology of industrial hemp and other indicators are converted by the waterlogging resistance coefficient, and then the core indicators are screened by the correlation coefficient. The entropy method is used to analyze and calculate the weight of each indicator, and the data of each indicator is multiplied by the corresponding weight and then added up, which is the "comprehensive score" of each material. The waterlogging resistance ranking of each material is obtained according to the comprehensive score; the evaluation results of the present invention are basically consistent with the observation of external morphological characteristics, which has guiding significance for the screening of waterlogged industrial hemp germplasm.

[0049] In addition, most of the existing waterlogging resistance evaluation methods use a single indicator evaluation or a combination of principal component analysis and membership function method, which have the disadvantages of too many measurement indicators, complicated processes, and lack of intuitiveness. The present invention provides a method for waterlogging resistance evaluation, which is to calculate the waterlogging resistance coefficient and correlation coefficient by measuring various indicators, screen out the core indicators, and use the entropy method to calculate the weights and comprehensive scores according to the core indicators, and then make an evaluation of whether it has high waterlogging resistance. Compared with the existing technology, the method is simpler, more intuitive, and has certain advancement. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] Figure 1 This is a heat map of correlation analysis between various indicators of different industrial hemp varieties under waterlogging stress of the present invention. The numbers in the upper right area of ​​the figure are the correlation coefficients between various indicators. The darker the font color, the stronger the correlation, and the lighter the font color, the weaker the correlation; the darker the color of the square in the lower left area, the stronger the correlation, and the lighter the color, the weaker the correlation. Red indicates positive correlation, and blue indicates negative correlation. * indicates significant correlation (p < 0.05), and ** indicates extremely significant correlation (p < 0.01).

[0051] Figure 2 This is a schematic diagram of a process for evaluating waterlogging resistance of industrial hemp according to an embodiment of the present invention;

[0052] Figure 3This is a schematic diagram of the overall morphology of different industrial hemp varieties on the 9th day of waterlogging stress in an embodiment of the present invention.

[0053] Note: CK is normal water treatment; WS is waterlogging stress treatment. DETAILED DESCRIPTION

[0054] In order to further explain the technical means and effects adopted by the present invention to achieve the predetermined invention purpose, the specific implementation methods, structures, features and effects thereof are described in detail below in conjunction with the accompanying drawings and preferred embodiments. In the following description, different "one embodiment" or "another embodiment" does not necessarily refer to the same embodiment. In addition, specific features, structures or characteristics in one or more embodiments may be combined in any suitable form.

[0055] Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs.

[0056] See also Figure 1-3 In this example, five industrial hemp varieties were used as research objects, and the "double pot method" was used for waterlogging stress treatment. The morphological and physiological indicators were combined to analyze the changes in four morphological indicators of plant height, stem diameter, aboveground dry weight and underground dry weight, and 12 physiological indicators of chlorophyll a content, chlorophyll b content, total chlorophyll content, carotenoid content, superoxide dismutase (SOD) activity, peroxidase (POD) activity, malondialdehyde (MDA) content, proline content, soluble protein content, soluble sugar content, relative conductivity and root activity (TTC reduction intensity). The waterlogging resistance coefficient was calculated and the correlation coefficient was analyzed. The morphological indicators and the physiological indicators with the greatest correlation with each morphological indicator were selected, and the entropy method was used for weight calculation and ranking to comprehensively evaluate the waterlogging resistance of industrial hemp.

[0057] The invention provides a method for comprehensively evaluating the waterlogging resistance of industrial hemp based on an entropy method and an application thereof.

[0058] The method comprises the following steps:

[0059] 1. Prepare industrial hemp materials and cultivate them:

[0060] In one embodiment of the present invention, four industrial hemp varieties mainly promoted in Yunnan, namely, 'Yunma No. 1', 'Yunma No. 7', 'Yunma No. 8', 'Yunma No. 10' and one industrial hemp variety mainly promoted in Guangxi, 'Bama Huoma', were selected as test materials. The five industrial hemp varieties collected above were subjected to waterlogging stress tests at the Institute of Plant Resources / College of Agriculture of Yunnan University. These varieties represent the currently mainly promoted industrial hemp varieties and have good representativeness.

[0061] 2. "Double-pot method" to simulate waterlogging stress:

[0062] The seeds of the five materials were sown in plastic flower pots, the specifications of which were holes at the bottom, and the outer diameter, inner diameter, bottom diameter, and height were 32, 27, 17, and 20 cm, respectively. The planting matrix was a mixed matrix of peat nutrient soil: garden soil: perlite = 5:4:1 (v:v:v), with a mass of about 0.8 kg of peat nutrient soil, 3.75 kg of garden soil, and 0.1 kg of perlite, and 10 g of compound fertilizer (N+P2O5+K2O≥38.0%) was mixed in each pot as base fertilizer. This ratio can provide a good growth environment for industrial hemp seedlings. Plant 6 pots of each variety, sow 18 seeds in each pot, and thin out the seedlings when the seedlings grow to 3 pairs of true leaves after germination, and set 6 seedlings in each pot. This ensures that each plant has enough growth space to avoid affecting the experimental results due to overcrowding of plants. During the period, normal management, watering at 9 am every day, 500 ml per pot (depending on the situation in rainy weather), to ensure that the surface of the matrix soil is moist but not waterlogged. After thinning, compound fertilizer or urea was used for topdressing depending on the condition of the hemp. During the rapid growth period of industrial hemp (about 70 cm high), five industrial hemp varieties were treated with waterlogging stress.

[0063] Each test material was divided into a normal water treatment group (CK) and a waterlogging stress treatment group (WS). CK was watered normally at 9 am every day, with 500 ml per pot. WS used the "double pot method" to place the perforated flower pots for growing industrial hemp into flower pots without holes at the bottom (outer diameter, inner diameter, bottom diameter, and height were 34, 29, 18, and 22 cm, respectively) for waterlogging stress treatment. Water was replenished at 9 am and 6 pm every day to make the soil water content supersaturated and keep the water surface 3 cm above the surface of the substrate soil. This treatment method can ensure that the plant roots are always in an over-humid environment, thereby inducing a waterlogging response.

[0064] 3. Determination of sampling time after waterlogging stress:

[0065] On the 9th day of waterlogging stress treatment, the morphological and physiological indicators of industrial hemp were measured. The 9th day was chosen for measurement because most plants have already shown varying degrees of waterlogging symptoms, such as leaf wilting or yellowing, but have not yet died. This time point can well reflect the differences in tolerance of different varieties to waterlogging.

[0066] 4. Index determination:

[0067] The morphological and physiological indices of each industrial hemp variety were measured. Before the index measurement, one pot of plants under different varieties and different treatment conditions were randomly selected for photographing, and three test plants under different varieties and different treatment conditions were selected for the measurement of various morphological and physiological indices. Among them, the physiological indices were measured by randomly selecting the 2nd to 5th pairs of unfolded leaves (avoiding leaf veins) or roots of three cannabis plants in each group, and the results were averaged.

[0068] The morphological indicators include plant height, stem diameter, aboveground dry weight, and underground dry weight. The plant height is measured with a tape measure starting from the bottom of the hemp stem and ending at the tip; the stem diameter is measured with a vernier caliper (accuracy 0.01cm) to measure the main stem diameter 3cm from the soil surface; the aboveground dry weight is measured by placing the aboveground part of the plant in an oven at 60℃ for 72h, and then taking it out and weighing it; the underground dry weight is measured by digging out the roots of the plant, gently washing the soil with clean water, using filter paper to absorb the surface moisture, placing it in an oven at 60℃ for 72h, and then taking it out and weighing it. These morphological indicators can intuitively reflect the growth status of plants under waterlogging conditions.

[0069] Physiological indicators include chlorophyll a content, chlorophyll b content, total chlorophyll content, carotenoid content, superoxide dismutase (SOD) activity, peroxidase (POD) activity, malondialdehyde (MDA) content, proline content, soluble protein content, soluble sugar content, relative conductivity, and root activity (TTC reduction intensity). Among them, chlorophyll a, chlorophyll b, total chlorophyll content, and carotenoid content were determined by ethanol extraction method, SOD activity was determined by nitroblue tetrazolium (NBT) photoreduction method, POD activity was determined by guaiacol colorimetry, MDA content was determined by thiobarbituric acid (TBA) colorimetry, proline content was determined by acid ninhydrin method, soluble protein content was determined by Coomassie brilliant blue method, soluble sugar content was determined by anthrone colorimetry, relative conductivity was determined by immersion method, and root activity was determined by TTC method. These physiological indicators can reflect the physiological responses of plants under waterlogging stress from different angles, providing a rich data basis for the comprehensive evaluation of waterlogging tolerance.

[0070] 5. Calculation of waterlogging resistance coefficient:

[0071] Microsoft Excel 2021 was used to process and statistically analyze the selected 16 morphological and physiological indicators, and the waterlogging resistance coefficient (β) was calculated based on the measured values ​​of the normal water treatment group (CK) and the waterlogging stress treatment group (WS).

[0072] Calculation of waterlogging resistance coefficient (β):

[0073] Waterlogging tolerance coefficient (β) = measured value of waterlogging stress treatment group / measured value of control group.

[0074] The control group is the normal water treatment group. The closer the β value is to 1, the less the index is affected by waterlogging and the stronger the waterlogging resistance is. This treatment method can standardize the data of different indicators, which is convenient for subsequent comparison and analysis.

[0075] Table 1 Waterlogging resistance coefficient (β) of each index

[0076]

[0077]

[0078] 6. Correlation coefficient analysis:

[0079] Origin2021 was used to draw a correlation coefficient heat map. Correlation analysis was performed on 16 indicators of five industrial hemp varieties under waterlogging stress, and physiological indicators with high correlation coefficients with morphological indicators were screened. The results showed that plant height was extremely significantly correlated with underground dry weight (p < 0.01, the same below), with a correlation coefficient of 0.99, and significantly correlated with carotenoid content (p < 0.05, the same below), with a correlation coefficient of 0.96; the correlation between stem thickness and various physiological indicators did not reach a significant level, but the correlation coefficient between stem thickness and proline content was the highest, at 0.77; the aboveground dry weight was significantly correlated with the underground dry weight, with a correlation coefficient of 0.91, and was extremely significantly correlated with the chlorophyll b content, with a correlation coefficient of -0.97; the underground dry weight was significantly correlated with the chlorophyll b and carotenoid contents, with correlation coefficients of -0.88 and 0.93, respectively ( Figure 1 ). This method can effectively reduce the number of indicators, avoid information redundancy, and improve the efficiency and accuracy of evaluation.

[0080] In summary, in addition to the four morphological indices, a total of three physiological indices with high correlation coefficients with the morphological indices were selected for comprehensive evaluation of waterlogging tolerance, namely, carotenoid content, proline content, and chlorophyll b content.

[0081] 7. Comprehensive evaluation of waterlogging resistance: entropy analysis

[0082] Based on the morphological indicators of each industrial hemp variety and the waterlogging resistance coefficient of physiological indicators screened out by correlation coefficient analysis, Excel2021 and SPSSAP-online SPSS analysis software were used to complete the weight calculation, and the entropy method was used to analyze the waterlogging resistance coefficients of four morphological indicators and three physiological indicators of five industrial hemp varieties under waterlogging stress.

[0083] 7.1 Direction and dimension processing:

[0084] Positive indicators:

[0085] Contrarian Indicators:

[0086] Among them, positive indicators refer to indicators with larger data, the better, and negative indicators refer to indicators with smaller data, the better; X min Indicates the minimum value of the indicator, X max Indicates the maximum value of the indicator. This processing can eliminate the dimensional differences between different indicators and make the data comparable.

[0087] 7.2 Entropy value calculation formula:

[0088] (1) Information entropy value e:

[0089] ① Calculate the proportion of the i-th sample value under the j-th indicator:

[0090] ② Calculate the information entropy of each indicator: in,

[0091] (2) Information utility value d j d j =1-e j ;

[0092] (3) Weight coefficient value W j :

[0093] The advantage of the entropy method is that it can objectively determine the weight of each indicator and avoid the influence of subjective factors.

[0094] As can be seen from Table 2, the entropy method was used to calculate the weights of plant height, stem diameter, aboveground dry weight, underground dry weight, chlorophyll b content, carotenoid content, and proline content, and the weights were 0.198, 0.080, 0.167, 0.198, 0.091, 0.160, and 0.106, respectively. And the weights of each indicator are relatively uniform, all around 0.143. These weights reflect the relative importance of each indicator in evaluating the waterlogging resistance of industrial hemp.

[0095] Table 2 Summary of weight calculation results using entropy method

[0096]

[0097]

[0098] 8. Calculate the comprehensive score:

[0099] The comprehensive score is the decisive indicator used by the entropy method for the final comprehensive evaluation. After obtaining the weight of each indicator, the data of each indicator is multiplied by the corresponding weight and then added up to get the "comprehensive score". The higher the comprehensive score, the better the variety's waterlogging resistance.

[0100] The results showed that the ranking of waterlogging resistance of the five industrial hemp varieties was 'Yunma No. 7' > 'Yunma No. 8' > 'Yunma No. 10' > 'Yunma No. 1' > 'Bama Huoma'. Among the five varieties, 'Yunma No. 7' had the highest comprehensive score of 0.812, so it had the strongest waterlogging resistance, while 'Bama Huoma' had the lowest comprehensive score of 0.222, and had the weakest waterlogging resistance (Table 3).

[0101] Table 3 Comprehensive scores and waterlogging resistance rankings of industrial hemp varieties calculated by entropy method

[0102] variety Comprehensive score Ranking Yunma No.1 0.242 4 Yunma No.7 0.812 1 Yunma No.8 0.669 2 Yunma No.10 0.372 3 Bama Hemp 0.222 5

[0103] An important application of the method of the present invention is to screen varieties or individuals with strong waterlogging resistance in industrial hemp breeding. By evaluating the waterlogging resistance of different industrial hemp varieties or breeding materials, breeders can quickly and accurately identify materials with strong waterlogging resistance for further breeding work. This is of great significance for improving the stress resistance of industrial hemp, especially improving its adaptability in the context of climate change.

[0104] In general, the comprehensive evaluation method for waterlogging resistance of industrial hemp based on the entropy method provided by the present invention has the following advantages: first, it comprehensively considers morphological and physiological indicators, and comprehensively reflects the waterlogging resistance characteristics of plants; second, by introducing waterlogging resistance coefficient and correlation analysis, the evaluation process is effectively simplified; third, the entropy method is used to determine the index weight, avoiding the influence of subjective factors; finally, the method is simple to operate, the evaluation results are intuitive, and it is easy to apply in actual breeding work. These characteristics make this method have broad application prospects in the field of industrial hemp waterlogging resistance evaluation and breeding.

[0105] It should be noted that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for comprehensive evaluation of waterlogging resistance of industrial hemp based on entropy method, characterized in that: The following steps are involved: First, industrial hemp materials were prepared and cultivated. When the plants grew to a height of about 70 cm in the rapid growth period, the double-pot method was used for waterlogging stress treatment, in which the perforated flower pots for planting industrial hemp were placed in flower pots without holes at the bottom. Water was replenished regularly every day to make the soil water content supersaturated, and the water level was kept 3 cm above the surface of the substrate soil; Then, on the 9th day after waterlogging stress treatment, the morphological and physiological indices of industrial hemp were measured, wherein the morphological indices included plant height, stem diameter, aboveground dry weight and underground dry weight, and the physiological indices included chlorophyll a content, chlorophyll b content, total chlorophyll content, carotenoid content, superoxide dismutase SOD activity, peroxidase POD activity, malondialdehyde MDA content, proline content, soluble protein content, soluble sugar content, relative conductivity and root activity; Next, the waterlogging resistance coefficient of each indicator was calculated based on the measurement results, and correlation analysis was performed to screen the core indicators; Subsequently, the data of the selected core indicators were standardized, and the entropy method was used to analyze and calculate the weight of each indicator; Finally, based on the calculated indicator weights, the comprehensive score was calculated and the waterlogging resistance was evaluated.

2. The method according to claim 1, characterized in that The calculation formula of the waterlogging resistance coefficient β is: β = measured value of waterlogging stress treatment group / measured value of control group Among them, the control group was the normal water treatment group. The closer the β value was to 1, the less the index was affected by waterlogging and the stronger the waterlogging resistance was.

3. The method according to claim 1, characterized in that The correlation analysis adopts the correlation coefficient heat map method, and by calculating the correlation coefficients between the indicators, the physiological indicators with the greatest correlation with the morphological indicators are selected as the core indicators, including: Calculate the correlation coefficient between plant height and other indicators, and select the physiological indicator with the largest absolute value of the correlation coefficient; Calculate the correlation coefficient between stem diameter and other indicators, and select the physiological indicator with the largest absolute value of the correlation coefficient; Calculate the correlation coefficient between aboveground dry weight and other indicators, and select the physiological indicator with the largest absolute value of the correlation coefficient; Calculate the correlation coefficient between underground dry weight and other indicators, and select the physiological indicator with the largest absolute value of the correlation coefficient.

4. The method according to claim 1, characterized in that: The data standardization process uses the following formula: Positive indicators: Contrarian Indicators: Among them, X is the original value of the indicator, X min is the minimum value of the indicator, X max It is the maximum value of the indicator; the larger the positive index value, the better the indicator is, and the smaller the reverse index value, the better the indicator is.

5. The method according to claim 1, characterized in that The entropy analysis includes the following steps: First, calculate the proportion P of the i-th sample value under the j-th indicator to the total value of the indicator ij : Among them, X ij is the standardized value of the i-th sample under the j-th indicator; Then, calculate the information entropy e of each indicator j : in, n is the number of samples; Next, calculate the information utility value d of each indicator j : d j =1-e j Finally, calculate the weight coefficient W of each indicator j :

6. The method according to claim 1, characterized in that The calculation method of the comprehensive score is: Multiply the waterlogging resistance coefficient of each indicator by the corresponding weight coefficient, and then add them up to get the final comprehensive score. The higher the comprehensive score, the stronger the waterlogging resistance of the industrial hemp material.

7. The method according to claim 1, characterized in that The method for determining the morphological index comprises: Use a tape measure to measure the height of the cannabis stalk starting at the base and ending at the tip; The diameter of the main stem at 3 cm above the soil surface was measured using a vernier caliper as the stem diameter; The aboveground parts of the plants were baked at 60°C for 72 h and then weighed to obtain the aboveground dry weight; The roots of the plants were washed and baked at 60°C for 72 h, and then weighed to obtain the dry weight of the underground part.

8. The method according to claim 1, characterized in that The method for measuring the physiological index comprises: The ethanol extraction method was used to determine the contents of chlorophyll a, chlorophyll b, total chlorophyll and carotenoids; the nitroblue tetrazolium NBT photoreduction method was used to determine the SOD activity; the guaiacol colorimetric method was used to determine the PO D activity; the thiobarbituric acid TBA colorimetric method was used to determine the MDA content; the acid ninhydrin method was used to determine the proline content; the Coomassie brilliant blue method was used to determine the soluble protein content; the anthrone colorimetric method was used to determine the soluble sugar content; the immersion method was used to determine the relative conductivity; and the TTC method was used to determine the root activity.

9. The method according to any one of claims 1 to 8, characterized in that The industrial hemp materials include different varieties of industrial hemp. By evaluating the waterlogging resistance of different varieties, industrial hemp varieties with stronger waterlogging resistance can be screened out.

10. Application of the method according to any one of claims 1 to 9 in industrial hemp breeding, characterized in that: By evaluating the waterlogging resistance of different industrial hemp varieties or breeding materials, varieties or individuals with strong waterlogging resistance can be screened out for further breeding work.

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