阅读说明：本技术 一种定量植物胞内水分利用效率和相对持水时间的方法 (Method for quantifying utilization efficiency and relative water retention time of intracellular water of plant ) 是由 吴沿友 张承 于睿 苏跃 吴沿胜 方蕾 吴明开 王瑞 于 2019-10-10 设计创作，主要内容包括：本发明公开了一种定量植物胞内水分利用效率和相对持水时间的方法,属于农业工程和农作物信息检测技术领域,测定不同夹持力下植物叶片生理阻抗和生理电容,进一步计算植物叶片生理容抗；构建植物叶片的生理电容随夹持力变化、植物叶片的生理阻抗随夹持力变化、植物叶片的生理容抗随夹持力变化模型,利用上述三个模型的参数计算植物叶片的比有效厚度、固有生理阻抗、固有生理容抗,进而计算叶片相对持水量、叶片胞内水分利用效率、相对持水时间和叶片导水速率。本发明不仅可以快速、在线定量检测不同环境下不同植物对水分的持有能力和供需能力,测定的结果具有可比性,而且还可以用生物物理指标表征不同环境下不同植物对环境的适应特征。(The invention discloses a method for quantifying the utilization efficiency and the relative water retention time of intracellular water of a plant, which belongs to the technical field of agricultural engineering and crop information detection, and is used for measuring the physiological impedance and the physiological capacitance of a plant leaf under different clamping forces and further calculating the physiological capacitive impedance of the plant leaf; and (3) constructing a model of the physiological capacitance of the plant leaf changing along with the clamping force, the physiological impedance of the plant leaf changing along with the clamping force and the physiological capacitance of the plant leaf changing along with the clamping force, calculating the specific effective thickness, the inherent physiological impedance and the inherent physiological capacitance of the plant leaf by using the parameters of the three models, and further calculating the relative water holding capacity of the leaf, the intracellular water utilization efficiency of the leaf, the relative water holding time and the water diversion rate of the leaf. The method can rapidly and quantitatively detect the holding capacity and supply and demand capacity of different plants under different environments on line, the detection result is comparable, and the biophysical indexes can be used for representing the adaptive characteristics of different plants under different environments to the environments.)

1. A method for quantifying the intracellular water utilization efficiency and relative water retention time of a plant is characterized by comprising the following steps:

step one, connecting a measuring device with an LCR tester;

selecting fresh branches of the plant to be detected;

collecting leaves to be detected from the fresh branches, and soaking the leaves in distilled water;

step four, sucking water on the surface of the leaf, immediately clamping the leaf to be detected between parallel electrode plates of a detection device, setting detection voltage and frequency, setting different clamping forces by changing the mass of an iron block, and simultaneously detecting the physiological capacitance and the physiological impedance of the plant leaf under different clamping forces in a parallel mode;

calculating physiological capacitive reactance according to the physiological capacitance of the plant leaves;

constructing a model of physiological capacitance of the plant leaves changing along with the clamping force to obtain each parameter of the model;

constructing a model of the physiological impedance of the plant leaves changing along with the clamping force to obtain each parameter of the model;

step eight, constructing a model of the physiological capacitive reactance of the plant leaf changing along with the clamping force to obtain each parameter of the model;

step nine, acquiring the specific effective thickness d of the plant leaves according to the parameters in the model in the step six;

step ten, acquiring the inherent physiological impedance IZ of the plant leaf according to the parameters in the model in the step seven;

step eleven, acquiring inherent physiological capacitive reactance IXC of the plant leaves according to the parameters in the model in the step eight;

step twelve, calculating an inherent physiological capacitance ICP according to the inherent physiological capacitive reactance IXC;

step thirteen, calculating the relative water holding capacity Rqwm of the blade according to the inherent physiological capacitance ICP;

fourteen, calculating the intracellular water utilization efficiency WUecp of the leaves to be detected according to the specific effective thickness d of the plant leaves and the relative water capacity Rqwm of the leaves;

step fifteen, acquiring the relative water retention time RTwm of the plant based on the electrophysiological parameters according to the inherent physiological capacitance ICP and the inherent physiological impedance IZ of the plant leaf;

sixthly, calculating the water guide rate VT of the blade according to the relative water holding capacity Rqwm of the blade and the relative water holding time RTwm.

2. The method for quantifying intracellular water use efficiency and relative water retention time of a plant according to claim 1, wherein: the setting method of different clamping forces in the fourth step comprises the following steps: by adding iron blocks of different masses, according to the formula of gravilogy: calculating clamping force F as (M + M) g, wherein F is the clamping force and has the unit of N; m is the mass of the iron block, and M is the mass of the plastic rod and the electrode slice, kg; g is an acceleration of gravity of 9.8N/kg.

3. The method for quantifying intracellular water use efficiency and relative water retention time of a plant according to claim 1, wherein: in the fifth step, a calculation formula of the physiological capacitive reactance of the plant leaves is as follows:

4. The method for quantifying intracellular water use efficiency and relative water retention time of a plant according to claim 1, wherein: in the sixth step, the change equation of the physiological capacitance Cp of the plant leaf along with the clamping force F is as follows:wherein, Delta H is the internal energy of the system, U is the test voltage, and d is the specific effective thickness of the plant leaves; order to

5. The method for quantifying intracellular water use efficiency and relative water retention time of a plant according to claim 1, wherein: in the seventh step, the physiological impedance of the plant leaf changes along with the clamping force,

6. The method for quantifying intracellular water use efficiency and relative water retention time of a plant according to claim 1, wherein: in the step eight, the physiological capacitive reactance of the plant leaf changes along with the clamping force,

7. The method for quantifying intracellular water use efficiency and relative water retention time of plants according to claim 4, wherein: in the ninth step, the method for obtaining the specific effective thickness d of the plant leaf according to the parameters in the sixth model comprises the following steps: will be provided with

8. The method for quantifying intracellular water use efficiency and relative water retention time of a plant according to claim 1, wherein: in the step ten, the method for obtaining the inherent physiological impedance IZ of the plant leaf according to the parameters in the model in the step seven comprises the following steps: IZ ═ y₀+k₁(ii) a In the eleventh step, the method for obtaining the intrinsic physiological capacitive reactance IXC of the plant leaves according to the parameters in the model in the eighth step comprises the following steps: IXC ═ p₀+k₂。

9. The method for quantifying intracellular water use efficiency and relative water retention time of a plant according to claim 1, wherein: in the twelfth step, the method for calculating the intrinsic physiological capacitance ICP according to the intrinsic physiological capacitive reactance IXC includes:wherein IXC is the inherent physiological capacitive reactance of plant leaves, ICP is the inherent physiological capacitance, f is the test frequency, and pi is the circumference ratio equal to 3.1416; in the step thirteen, the method for calculating the relative water holding capacity Rqwm of the blade according to the intrinsic physiological capacitance ICP comprises the following steps:

10. the method for quantifying intracellular water use efficiency and relative water retention time of a plant according to claim 1, wherein: in the fourteenth step, the method for calculating the intracellular water utilization efficiency WUecp of the leaf to be detected according to the specific effective thickness d of the plant leaf and the relative water holding capacity Rqwm of the leaf comprises the following steps:

Technical Field

The invention belongs to the technical field of agricultural engineering and crop information detection, and particularly relates to a method for quantifying the intracellular water utilization efficiency and the relative water retention time of plants, which can rapidly and quantitatively detect the water holding capacity and the water supply and demand capacity of different plants in different environments on line, has comparable determination results, can represent the adaptive characteristics of different plants in different environments to the environment by using biophysical indexes, and provides scientific basis for accurate irrigation and water management of crops.

Background

Water is the main component of protoplasm, is a good medium for absorption and transportation of substances, and directly participates in important metabolic processes in the body. All normal life activities of plants must be coordinated under the condition that the water content is quite saturated, otherwise, the normal life activities are damaged or even stopped. Since green plants are autotrophic, efficient photosynthesis is essential to maintain normal life activities. For this reason, it must develop a large leaf area, adequately receive sunlight, and constantly exchange gas with the surrounding environment (absorb carbon dioxide and release oxygen). However, since the water potential of the atmosphere is much lower than that of the plant body, the surface receiving sunlight is necessarily the surface for water evaporation, and the gas exchange channel is also the channel for water vapor dissipation. Therefore, on one hand, the plant continuously absorbs water from the environment through the root system and is distributed to each part of the plant body through the transportation of the root and the stem so as to meet the requirement of normal life activities; on the other hand, the plant body inevitably loses a large amount of water to the environment, so that the plant body is actually in a dynamic balance of continuous water absorption and continuous water loss. When the water loss is not compensated by the water absorption capacity of the plant, the plant often has a wilting phenomenon, and leaves, flowers and fruits can fall off or even die when the plant is serious.

The leaf is the most important component of the leaf, is mostly a thin green flat body, has a large surface area due to the thin and flat shape, can shorten the distance between mesophyll cells and the leaf surface, and leaves for supporting and conducting are also in a network state. These features are favorable to gas exchange and light energy absorption, water, nutrients and photosynthetic product output, and are perfect adaptation to photosynthesis and transpiration. Leaves are the most sensitive organs to various metabolisms including water metabolism. The moisture status of leaves plays a crucial role in the growth and development of plants. Therefore, the water holding time and water holding amount of the leaves and the utilization efficiency of the water holding amount in the leaves have important significance on the water metabolism of plants.

Since young leaves are small in proportion, mature leaves play a decisive role in water metabolism. The leaves of fully expanded leaves are all mature leaves, their cells all have a central vacuole, in mesophyll cells, the vacuole and cytoplasm occupy most of the space in the cell, and their water absorption mode is mainly osmotic water absorption. Whether a cell or an organelle, they are externally coated with a cell membrane. The cell membrane mainly comprises lipid (mainly phospholipid) (accounting for about 50% of the total amount of the cell membrane), protein (accounting for about 40% of the total amount of the cell membrane), carbohydrate (accounting for about 2% -10% of the total amount of the cell membrane) and the like; wherein the main components are protein and lipid. The phospholipid bilayer is the basic scaffold that constitutes the cell membrane. Under an electron microscope, the membrane can be divided into three layers, namely an electronic dense band (hydrophilic part) with the thickness of about 2.5nm is respectively arranged at the inner side and the outer side of the membrane, and a transparent band (hydrophobic part) with the thickness of 2.5nm is clamped in the middle. Thus, the cell (apparatus) can be regarded as a concentric sphere capacitor, but this capacitor becomes a complex capacitor having both the inductor and the resistor functions due to the peripheral and intrinsic proteins on the membrane.

There are vacuoles of varying sizes in plant cells. Mature plant cells have a large central vacuole which typically occupies 30% of the cell volume, and more up to 90%. Whereas the vacuole volume of mature leaf cells is typically between 50% and 90%. Since the vacuole is surrounded by a single membrane unit, the major component of which is water and the protoplasm is also primarily water, the volume of leaf cells can essentially represent the water holding capacity of the leaf.

LCR can measure physiological capacitance and physiological impedance of the leaf blade, and the capacitance has obvious relation with the volume of the cell, so that the cell volume can be represented by the capacitance, and the volume of the cell (device), especially the cell (device) unfolding the leaf blade, is in direct proportion to the water holding capacity, so that the water holding capacity of the cell can be obtained. The water holding capacity supports the growth of plant cells and represents the intracellular water utilization efficiency (different from the plant water utilization efficiency in the general sense, the transpiration effect and the simultaneous water absorption transpiration effect are not considered). Then, the water holding time and the water conduction rate can be obtained through the measurement of the impedance.

Disclosure of Invention

The invention aims to provide a method for quantifying the utilization efficiency and the relative water retention time of intracellular water of a plant, which not only fills the blank that the retention capacity and the supply and demand capacity of the plant to water are represented by biophysical indexes, but also fills the blank that the biophysical indexes are used for representing the adaptive characteristics of different plants to the environment under different environments, provides an effective method for the research of the intracellular water metabolism of the plant, and provides a scientific basis for the accurate irrigation and the water management of crops.

In order to solve the technical problems, the invention adopts the following specific technical scheme:

a method for quantifying the intracellular water utilization efficiency and relative water retention time of a plant comprises the following steps:

a method for quantifying the intracellular water utilization efficiency and relative water retention time of a plant is characterized by comprising the following steps:

step one, connecting a measuring device with an LCR tester;

selecting a fresh branch of the plant to be detected, and wrapping the base of the branch;

collecting leaves to be detected from the fresh branches, and soaking the leaves in distilled water for 30 minutes;

step four, sucking water on the surface of the leaf, immediately clamping the leaf to be detected between parallel electrode plates of a detection device, setting detection voltage and frequency, setting different clamping forces by changing the mass of an iron block, and simultaneously detecting the physiological capacitance and the physiological impedance of the plant leaf under different clamping forces in a parallel mode;

calculating physiological capacitive reactance according to the physiological capacitance of the plant leaves;

constructing a model of physiological capacitance of the plant leaves changing along with the clamping force to obtain each parameter of the model;

constructing a model of the physiological impedance of the plant leaves changing along with the clamping force to obtain each parameter of the model;

step eight, constructing a model of the physiological capacitive reactance of the plant leaf changing along with the clamping force to obtain each parameter of the model;

step nine, acquiring the specific effective thickness d of the plant leaves according to the parameters in the model in the step six;

step ten, acquiring the inherent physiological impedance IZ of the plant leaf according to the parameters in the model in the step seven;

step eleven, acquiring inherent physiological capacitive reactance IXC of the plant leaves according to the parameters in the model in the step eight;

step twelve, calculating an inherent physiological capacitance ICP according to the inherent physiological capacitive reactance IXC;

step thirteen, calculating the relative water holding capacity Rqwm of the blade according to the inherent physiological capacitance ICP;

fourteen, calculating the intracellular water utilization efficiency WUecp of the leaves to be detected according to the specific effective thickness d of the plant leaves and the relative water capacity Rqwm of the leaves;

step fifteen, acquiring the relative water retention time RTwm of the plant based on the electrophysiological parameters according to the inherent physiological capacitance ICP and the inherent physiological impedance IZ of the plant leaf;

sixthly, calculating the water guide rate VT of the blade according to the relative water holding capacity Rqwm of the blade and the relative water holding time RTwm.

Further, the setting method of the different clamping forces in the fourth step is as follows: by adding iron blocks of different masses, according to the formula of gravilogy: calculating clamping force F as (M + M) g, wherein F is the clamping force and has the unit of N; m is the mass of the iron block, and M is the mass of the plastic rod and the electrode slice, kg; g is an acceleration of gravity of 9.8N/kg.

Further, in the fifth step, a calculation formula of the physiological capacitive reactance of the plant leaf is as follows:

wherein Xc is the physiological capacitive reactance of the plant leaves, C is the physiological capacitance of the plant leaves, f is the test frequency, and the circumference ratio is not equal to 3.1416.

Further, in the sixth step, the change equation of the physiological capacitance Cp of the plant leaf with the clamping force F is as follows:

wherein, Delta H is the internal energy of the system, U is the test voltage, and d is the specific effective thickness of the plant leaves; order to

The change equation may be transformed into Cp ═ x₀+ hF; wherein x₀And h is a model parameter.

Further, in the seventh step, the physiological impedance of the plant leaf changes along with the clamping force, the model is based on the Nernst equation

Derived, wherein Z is impedance, E is electromotive force, E is⁰Is a standard electromotive force, R₀Is the ideal gas constant, T is the temperature, Q_iDielectric substance concentration, Q, in response to physiological impedance within the cell membrane_oConcentration of dielectric substances in response to physiological impedance outside cell membrane, J₀Dielectric substance concentration Q being the response of physiological impedance in cell membrane_iProportional coefficient of transformation between impedance and membrane internal and external response physiological resistanceThe total amount of dielectric substance Q ═ Q_i+Q_o，F₀Is the Faraday constant, n_ZIs the number of dielectric mass transfers in response to physiological impedance; e can be used for doing work, PV is proportional to PV (a is aE), a is the coefficient of converting electromotive force into metabolic energy, V is the volume of the plant cells, P is the pressure to which the plant cells are subjected, and the pressure P is expressed by a pressure formulaCalculating F as clamping force, S as effective area under the action of the polar plate and d as specific effective thickness of the plant leaf;

the deformation is as follows:

and is further transformed into

Due to the specific effective thickness of the plant leavesTherefore, the temperature of the molten metal is controlled,

the deformation is as follows:

order to

The model of the physiological impedance of the plant leaf changing along with the clamping force can be deformed into

Wherein y is₀、k₁And b₁Are parameters of the model.

Further, in the eighth step, the plant leavesThe physiological capacitive reactance of the model is changed along with the clamping force,

the model is based on the Nernst equation

Deduced, wherein Xc is capacitive reactance, E is electromotive force, E⁰Is a standard electromotive force, R₀Is the ideal gas constant, T is the temperature, X_iConcentration of dielectric substances, X, in response to physiological capacitive impedance within cell membranes_oConcentration of dielectric substances, L, in response to physiological capacitive reactance outside the cell membrane₀Concentration X of dielectric substance responsive to physiological capacitive impedance in cell membrane_iThe ratio coefficient of conversion between the dielectric substance and the physiological capacitive reactance, and the total amount of the dielectric substance X which responds to the physiological capacitive reactance inside and outside the membrane is X_i+X_o，F₀Is the Faraday constant, n_XCIs the number of dielectric mass transfers in response to physiological capacitive reactance; e can be used for doing work, PV is proportional to PV (a is aE), a is the coefficient of converting electromotive force into metabolic energy, V is the volume of the plant cells, P is the pressure to which the plant cells are subjected, and the pressure P is expressed by a pressure formula

Calculating F as clamping force, S as effective area under the action of the polar plate and d as specific effective thickness of the plant leaf;

the deformation is as follows:

and is further transformed into

Due to the specific effective thickness of the plant leaves

Therefore, the temperature of the molten metal is controlled,

the deformation is as follows:

order toThe model of the physiological capacitance of the plant leaf changing along with the clamping force can be deformed into

Wherein p is₀、k₂And b₂Are parameters of the model.

Further, in the ninth step, the method for obtaining the specific effective thickness d of the plant leaf according to the parameters in the sixth model comprises the following steps: the process as claimed in claim 6

Is deformed into

And calculating the specific effective thickness d of the plant leaf according to the h and the test voltage U.

Further, in the step ten, the method for obtaining the inherent physiological impedance IZ of the plant leaf according to the parameters in the model in the step seven comprises the following steps: IZ ═ y₀+k₁。

Further, in the eleventh step, the method for obtaining the intrinsic physiological capacitive reactance IXC of the plant leaf according to the parameters in the model in the eighth step comprises the following steps: IXC ═ p₀+k₂。

Further, in the step twelve, the method for calculating the intrinsic physiological capacitance ICP according to the intrinsic physiological capacitance IXC includes:

wherein IXC is the inherent physiology of plant leavesCapacitive reactance, ICP is the intrinsic physiological capacitance, f is the test frequency, and π is the circumferential ratio equal to 3.1416.

Further, in the thirteenth step, a method for calculating the relative water holding capacity RQwm of the blade according to the intrinsic physiological capacitance ICP in the thirteenth step is as follows:

further, in the fourteenth step, the method for calculating the intracellular water utilization efficiency WUecp of the leaf to be detected according to the specific effective thickness d of the plant leaf and the relative water capacity Rqwm of the leaf comprises the following steps:

further, in the fifteenth step, according to the intrinsic physiological capacitance ICP and the intrinsic physiological impedance IZ of the plant leaf, a calculation formula of the relative water retention time RTwm of the plant based on the electrophysiological parameter is obtained as follows: RTwm ═ ICP × IZ.

Further, in the sixteenth step, a calculation formula for calculating the water guide rate VT of the blade according to the relative water holding capacity RQwm and the relative water holding time RTwm of the blade is as follows:

the invention has the following beneficial effects:

1. the invention can rapidly and quantitatively detect the specific effective thickness, the inherent physiological impedance, the inherent physiological capacitive reactance, the inherent physiological capacitance, the relative water holding capacity of the leaves, the intracellular water utilization efficiency of the leaves, the relative water holding time of the plants and the water guide rate of the leaves in different environments on line, and the detection result is not changed due to the change of the detection condition and has comparability.

2. According to the invention, the water holding capacity and the water supply and demand capacity of different plants are represented by electrophysiological indexes through quantitative determination of the relative water holding capacity and the water guide rate of the leaves.

3. According to the invention, the utilization efficiency of intracellular water of the leaves and the relative water retention time of the plants are measured, and the electricity physiological indexes are used for representing the adaptive characteristics of different plants in different environments to the environment, so that an effective method is provided for the research of the intracellular water metabolism of the plants, and a scientific basis is provided for the accurate irrigation and water management of crops.

4. The invention is simple and convenient, has wide applicability and low price of required instruments.

Drawings

FIG. 1 is a schematic view of the structure of an assay device according to the present invention;

in the figure: 1. a support; 2. a foam board; 3. an electrode plate; 4. an electrical lead; 5. an iron block; 6. a plastic rod; 7. and (4) fixing clips.

Detailed Description

The invention is further described with reference to the following figures and examples.

The basic principle of the invention is as follows:

from the formula of gravimetry:

F＝(M+m)g (1)

wherein F is gravity (clamping force), N; m is the mass of the iron block, and M is the mass of the plastic rod and the electrode slice, kg; g is the acceleration of gravity of 9.8, N/kg.

The cytosol in the leaf is used as a dielectric medium, and the leaf is clamped between two parallel plate capacitor plates of a parallel plate capacitor to form the parallel plate capacitance sensor. The physiological capacitance of the plant leaf under different clamping forces is obtained by adding iron blocks with certain mass, and different pressure can lead to different changes of the concentration of the cytosol in the leaf, so that the elasticity and plasticity of leaf cells are changed, the change of the cytosol dielectric constant of leaf tissue between two capacitor plates is caused, and the electrophysiological indexes of plant physiological capacitance, impedance and the like are influenced.

The calculation formula of the physiological capacitive reactance of the plant leaves is as follows:

wherein Xc is the physiological capacitive reactance of the plant leaves, C is the physiological capacitance of the plant leaves, f is the test frequency, and pi is the circumference ratio equal to 3.1416.

The water content of the plant cells is related to the elasticity of the plant leaf cells, and under different clamping forces, different plant physiological capacitances are different.

The gibbs free energy equation is expressed as Δ G ═ Δ H + PV, and the energy equation of the capacitor is expressed as

W is the energy of the capacitor, equal to the work converted by gibbs free energy Δ G, i.e., W ═ Δ G; Δ H is the internal energy of the system (plant leaf system consisting of cells), P is the pressure to which the plant cells are subjected, V is the plant cell volume, U is the test voltage, C is the physiological capacitance of the plant leaf;

the pressure P to which the plant cells are subjected can be determined by a pressure formula:

wherein F is the clamping force, and S is the effective area under the action of the polar plate;

the change model of the physiological capacitance C of the plant leaf along with the clamping force F is as follows:

assuming that d represents the specific effective thickness of the plant leaf, then(2) The formula can be deformed into:

order to

(3) The formula can be deformed into:

C＝x₀+hF (4)

(4) formula (II) is a linear model, where x₀And h is a model parameter.

Due to the fact that

Thus, it is possible to provide

In the impedance measurement of the same object under the same environment, the impedance mainly depends on the concentration of dielectric substances responding to physiological impedance inside and outside the membrane, so the permeability and the water content of the membrane to various dielectric substances responding to physiological impedance determine the cell impedance, and for the leaf, the impedance further depends on the concentration of the dielectric substances responding to physiological impedance inside and outside the membrane. The external excitation changes the membrane permeability of the dielectric substance, the concentration of the dielectric substance responding to the physiological impedance inside and outside the membrane is influenced, the concentration difference of the dielectric substance responding to the physiological impedance inside and outside the membrane also obeys Nernst equation, and when the concentration of the dielectric substance responding to the physiological impedance outside the membrane is constant, the physiological impedance is inversely proportional to the concentration of the dielectric substance responding to the physiological impedance inside the cell, so that the relation between the physiological impedance of the cell and the external excitation can be deduced.

The water content of plant cell is related to the elasticity of plant leaf cell, and under different clamping forces, the permeability of dielectric substance responding to physiological impedance of different plant cell membranes is changed differently, so that the physiological impedance is different.

The expression of the nernst equation is as shown in equation (5):

wherein E is electromotive force, E⁰Is a standard electromotive force, R₀Is an ideal gas constant equal to 8.314570J.K^-1.mol^-1(ii) a T is temperature, in K; q_iDielectric substance concentration, Q, in response to physiological impedance within the cell membrane_oThe total amount of dielectric substance Q ═ Q in response to physiological impedance outside the cell membrane_i+Q_o，F₀Is the Faraday constant, equal to 96485C.mol^-1；n_ZIs the number of dielectric mass transfers in mol in response to physiological impedance.

The internal energy of electromotive force E can be converted into pressure to do work, and PV is proportional to PV ═ aE, namely:

wherein: p is the pressure to which the plant cell is subjected, a is the electromotive force conversion energy coefficient, and V is the plant cell volume;

the pressure P to which the plant cells are subjected can be determined by a pressure formula:

wherein F is the clamping force and S is the effective area under the action of the polar plate;

in mesophyllic cells, the vacuole and the cytoplasm occupy the vast majority of the intracellular space. For mesophyll cells, Q_oAnd Q_iThe sum is constant and equal to the total amount of dielectric substances Q, Q responding to physiological impedance inside and outside the membrane_iIt is proportional to the conductivity of the dielectric substance in response to the physiological impedance, which is the inverse of the impedance Z, and, therefore,can be expressed asZ is the impedance, J₀Dielectric substance concentration Q being the response of physiological impedance in cell membrane_iAnd impedance, and therefore (6) can become:

(7) is transformed to obtain

(8) Can become:

(9) the two sides of the formula are taken as indexes and can be changed into:

further modified, it is possible to obtain:

z in formula (11) is physiological impedance due to

The formula can be deformed into:

for the same blade to be measured in the same environment, the formula (12) is shown in the specification, wherein d, a and E⁰、R₀、T、n_Z、F₀、Q、J₀Are all constant values, orderThus, equation (12) can be transformed as:

(13) in the formula y₀、k₁And b₁Are parameters of the model. When F is 0 and is substituted into the formula (13), the plant leaf intrinsic physiological impedance IZ is obtained: IZ ═ y₀+k₁。

In the capacitive reactance measurement of the same object under the same environment, the capacitive reactance mainly depends on the concentration of dielectric substances responding to physiological capacitive reactance inside and outside the membrane, so the permeability of the membrane to various dielectric substances responding to physiological capacitive reactance determines the size of the cellular capacitive reactance, and for the leaf, the capacitive reactance further depends on the concentration of the dielectric substances responding to physiological capacitive reactance inside and outside the membrane. The external excitation changes the membrane permeability of the dielectric substance, the concentration of the dielectric substance responding to the physiological capacitive reactance inside and outside the membrane is influenced, the concentration difference of the dielectric substance responding to the physiological capacitive reactance inside and outside the membrane also obeys Nernst equation, and when the concentration of the dielectric substance responding to the physiological capacitive reactance outside the membrane is constant, the physiological capacitive reactance is inversely proportional to the concentration of the dielectric substance responding to the physiological capacitive reactance inside the cell, so that the relation between the physiological capacitive reactance inside the cell and the external excitation can be deduced.

The water content of plant cell is related to the elasticity of plant leaf cell, and under different clamping forces, the permeability of dielectric substance responding to physiological capacitive reactance of different plant cell membranes is changed differently, so that the physiological capacitive reactance is different.

The expression of the nernst equation is as in equation (14):

wherein E is electromotive force, E⁰Is a standard electromotive force, R₀Is an ideal gas constant equal to 8.314570J.K^-1.mol^-1(ii) a T is temperature, in K; x_iConcentration of dielectric substances, X, in response to physiological capacitive impedance within cell membranes_oThe total amount of dielectric substances X ═ X for responding to physiological capacitive impedance outside the cell membrane and responding to physiological capacitive impedance outside the cell membrane_i+X_o，F₀Is the Faraday constant, equal to 96485C.mol^-1；n_XCIs the number of dielectric material transitions in mol in response to physiological capacitive reactance.

The internal energy of electromotive force E can be converted into pressure to do work, and PV is proportional to PV ═ aE, namely:

wherein: p is the pressure to which the plant cell is subjected, a is the electromotive force conversion energy coefficient, and V is the plant cell volume;

the pressure P to which the plant cells are subjected can be determined by a pressure formula:

wherein F is the clamping force and S is the effective area under the action of the polar plate;

in mesophyllic cells, the vacuole and the cytoplasm occupy the vast majority of the intracellular space. For mesophyllic cells, X_oAnd X_iThe sum is certain and is equal to the total amount of dielectric substances X, X responding to physiological capacitive reactance inside and outside the membrane_iIs proportional to the conductivity of the dielectric material responsive to the physiological capacitive impedance, which is the inverse of the capacitive impedance Xc, and, therefore,can be expressed as

Xc is capacitive reactance, L₀Concentration X of dielectric substance responsive to physiological capacitive impedance in cell membrane_iThe proportionality coefficient for the conversion between the physiological capacitive reactance, therefore, (15) can become:

(16) is transformed to obtain

(17) Can become:

(18) the two sides of the formula are taken as indexes and can be changed into:

further modified, it is possible to obtain:

xc in formula (20) is a physiological capacitive reactance due to the specific effective thickness of the plant leaves(20) The formula can be deformed into:

for the same blade to be measured in the same environment, the formula (21) is shown in the specification, wherein d, a and E⁰、R₀、T、n_XC、F₀、X、L₀Are all constant values, order

Therefore, equation (21) can be transformed into:

(22) in the formula p₀、k₂And b₂Are parameters of the model. When F is 0 and is substituted into the formula (22), the plant leaf intrinsic physiological capacitive reactance IXC is obtained: IXC ═ p₀+k₂At this time, the capacitance converted from the intrinsic physiological capacitive reactance IXC of the plant leaf is the intrinsic physiological capacitance ICP. The formula for converting the intrinsic physiological capacitive reactance into the intrinsic physiological capacitance is as follows:

wherein IXC is the inherent physiological capacitive reactance of the plant leaves, ICP is the inherent physiological capacitance, f is the test frequency, and pi is the circumference ratio equal to 3.1416.

Since the cells (organs) are spherical structures, the growth and the volume growth of the cells are closely related, the volume of the cells of the same plant organ, especially leaves, is positively related to the volume of the vacuoles in the plant organ, and the main component of the vacuoles is water. The capacitance of the plant cell can be calculated by the formula of a concentric spherical capacitor:

where π is the circumference ratio equal to 3.1416, C is the capacitance of the concentric sphere capacitor, ε is the dielectric constant of the electrolyte, R₁、R₂The radii of the outer and inner spheres, respectively. In the cell (apparatus), R₂-R₁As thickness of the film, R₁≈R₂The same kind of cells (device) of the same plant tissue and organ, the thickness of the membrane is constant, epsilon is constant, so that the volume of the cells (device) has the following relation with the capacitance C of the cells:

(24) in the formula, the alpha of the same type of cells (device) of the same plant tissue and organ is fixed, and the volume of the cells (device), especially the cells (device) of the unfolded leaf blade, is in direct proportion to the water holding capacity, namely the water holding capacity of the cells and the water holding capacity of the leaves

Is proportional, therefore, can use

The method for representing the water holding capacity of the plant leaves and calculating the relative water holding capacity Rqwm of the leaves according to the inherent physiological capacitance ICP is as follows:

the specific effective thickness d of the plant leaf, which represents the growth of the cell, and the water holding capacity Rqwm supporting the growth of the plant cell d can be characterized as the intracellular water utilization efficiency WUecp of the leaf, and the calculation method is as follows:

according to ohm's law: current I_ZWhere U is the measurement voltage and IZ is the physiological current. Z is impedance; at the same time, the current is equal to the capacitance multiplied by the differential of the voltage over time, and the time t is the product of the capacitance and the impedance after integral conversion, so that the ICP and the impedance are based on the intrinsic physiological capacitanceThe inherent physiological impedance IZ of the plant leaf and the calculation formula of the relative water retention time RTwm of the plant based on the electrophysiological parameters are as follows: RTwm ═ ICP × IZ. According to the relative water holding capacity Rqwm and the relative water holding time RTwm of the blade, the water guiding rate VT of the blade can be calculated, and the calculation formula is as follows:

a device for measuring the utilization efficiency of intracellular water of plants and the relative water holding time of the plants is shown in figure 1 and comprises a bracket 1, a foam plate 2, an electrode plate 3, an electric lead 4, an iron block 5, a plastic rod 6 and a fixing clamp 7; the bracket 1 is of a rectangular frame structure, one side of the bracket is open, the upper end of the bracket 1 is provided with a through hole for a plastic rod 6 to extend into, the inward side of the lower end of the bracket 1 and the bottom end of the plastic rod 6 are respectively adhered with two foam plates 2, electrode plates 3 are embedded in the foam plates 2, a lead 4 is respectively led out from the two electrode plates 3 and used for being connected with an LCR tester (HIOKI 3532-50 type, Japan day place), an iron block 5 with fixed mass can be placed on the foam plates 2 of the plastic rod 6, and the physiological impedance and the physiological capacitance of the plant leaves are measured in a parallel mode; one end of the plastic rod 6, which is positioned in the bracket, is fixed by a fixing clamp 7, and when the lower end of the plastic rod is combined with the end of the bracket, the two electrode plates 3 are completely and correspondingly combined together; the electrode plate 3 is a circular electrode plate made of copper to reduce the edge effect of the electrode.

The method comprises the following steps: when the device is used, two wires 4 of the device are connected with a 9140 four-terminal test probe of an LCR tester, then the plastic rod 6 is lifted, two electrode plates 3 clamp plant leaves to be measured, the diameter of each electrode plate is 10mm, the measurement voltage is set to be 1.5V, the measurement frequency is 3000Hz, the mass of the plastic rod and the electrode plates and the mass of the iron block 5 are calibrated, and the physiological impedance and the physiological capacitance of the plant leaves under different clamping forces are measured in a parallel mode.