Maize leaf hydraulic conductivity and embolism curve measuring system and method based on transpiration driving method

Abstract

The invention belongs to the technical field of plant leaf hydraulic characteristic determination, and discloses a corn leaf hydraulic conductivity and embolism curve determination system and method, and the system comprises a corn leaf transpiration amount determination device in a stable state; the invention discloses a convenient leaf water potential balance, dehydration and leaf area measuring device and a dew-point water potential instrument, and the measuring system and method are not only suitable for measuring the maximum hydraulic conductance and embolism curve of the leaf in the whole growth period of corn, but also can realize the goal of simultaneously measuring the maximum hydraulic conductance and complete embolism curve of the corn leaf by using only one corn leaf. According to the method, blade mechanical damage caused by heterogeneity of blades at different positions and a pressure chamber method is avoided, and the measured maximum hydraulic conductivity and embolism curve fitting effect is better.

Description

Technical Field

[0001] This invention belongs to the field of plant leaf hydraulic property measurement technology, and in particular relates to a system and method for measuring the hydraulic conductivity and embolism curve of maize leaves based on the transpiration-driven method. Background Technology

[0002] Corn is an important food crop that requires a large supply of water during its growth. The hydraulic resistance of corn leaves accounts for a large part of the overall hydraulic resistance of the corn plant. By measuring the hydraulic conductivity of leaves and the embolism curve, we can quantify the water transport capacity of corn plants under different growth stages and environmental conditions (such as drought and humidity), and clarify the frequency and degree of leaf vascular embolism. This can serve as a basis for optimizing irrigation strategies and improving irrigation water use efficiency.

[0003] Existing devices and methods for measuring the hydraulic conductivity and embolism curve of plant leaves based on the transpiration-driven method can only be used for leaves with petioles. The unreasonable device design reduces the accuracy of the measurement data. The unstable leaf balance and dehydration environment increases the influence of the environment on the experimental results. The leaf position is unreasonable during the measurement process, the leaf area measurement is cumbersome, the differences between individual leaves have a large impact and the sampling volume is large. Summary of the Invention

[0004] The purpose of this invention is to provide a system and method for measuring the hydraulic conductivity and embolism curve of maize leaves based on the transpiration-driven method, so as to solve the problems existing in the prior art.

[0005] To achieve the above objectives, this invention provides a system for measuring the hydraulic conductivity and embolism curve of maize leaves based on the transpiration-driven method, comprising:

[0006] The transpiration measurement unit includes an induced evaporation module, an instantaneous transpiration measurement module, and a data recording module. The induced evaporation module includes an adjustable support, with a plant growth lamp mounted on the upper part of the support. A glass container is positioned below the plant growth lamp, and a water circulation cooling device is installed inside the glass container. A support plate is mounted on the lower part of the adjustable support, and the support plate has several through holes. A bayonet device is installed on the support plate, and a spiral silicone fixing connector is installed at the end of the bayonet device away from the support plate. A blade is installed inside the spiral silicone fixing connector to fix the spiral silicone. The instantaneous transpiration measurement module includes a 0.001% balance and a conical flask located above the balance. An iron stand is also provided on the balance, and a glass tube is movably mounted on the iron stand. The glass tube is connected to the spiral silicone fixing connector via a flexible hose. The 0.001% balance is connected to the data recording module.

[0007] The integrated unit for water potential regulation and rapid area measurement of maize leaves includes a cover, a perforated partition and a base plate that are fitted together from top to bottom.

[0008] The measurement system also includes a dew point potential meter for measuring the water potential of maize leaves.

[0009] Optionally, a conical bottle mouth evaporation suppression device is installed on the wall of the glass tube, and the conical bottle mouth evaporation suppression device corresponds to the position of the conical bottle.

[0010] Optionally, an vent valve is installed on the hose.

[0011] Optionally, the lid is provided with scale lines.

[0012] Optionally, the perforated partition plate has several through holes.

[0013] A method for determining the hydraulic conductance and embolism curve of maize leaves based on a transpiration-driven method, applied to the aforementioned system for determining the hydraulic conductance and embolism curve of maize leaves based on a transpiration-driven method, comprising:

[0014] Step 1: Prepare the experimental environment and prepare degassed ultrapure water;

[0015] Step 2: Obtain corn leaves and dissect and rehydrate them;

[0016] Step 3: Turn on the plant growth light, pour pure water into the glass container, turn on the cooling circulation device 3, place the conical flask on the 0.01% balance, fix the glass tube with the iron stand, pour the preset dose of degassed pure water into the conical flask, submerge the lower end of the glass tube 3-4 cm below the liquid surface of the conical flask, adjust the distance between the evaporation suppression device at the mouth of the conical flask and the conical flask to 1-2 mm, place the spiral silicone fixing connector below the degassed pure water liquid surface, connect the syringe with the exhaust valve to fill the tubing with liquid, turn off the switch on the spiral silicone fixing connector, and connect the 0.01% balance and the data recording module.

[0017] Step 4: Take out a rehydrated corn leaf, weigh it, and place it on the support board. Adjust the height of the adjustable support so that the plant growth light and glass container are 10-20cm away from the tip of the leaf. Perform light induction treatment on the corn leaf.

[0018] Step 5: Remove the corn leaves after the light-induced treatment and insert them into the spiral silicone fixing connector of the leaf fixing spiral silicone underwater. Adjust the spiral silicone fixing connector to ensure full contact between the leaf fixing spiral silicone and the spiral silicone fixing connector. Adjust the support plate to vent the hose. Fix the spiral silicone fixing connector to the bayonet device. Fix the bayonet device to the support plate and adjust the angle of the bayonet device so that the tilt angle of the corn leaves is consistent with the growth state. Adjust the height of the support plate so that the center point of the bayonet device is level with the water level of the balance. At the same time, take out the next rehydrated leaf and place it on the support plate for light-induced treatment under a plant growth lamp and glass container.

[0019] Turn on the switch on the bayonet device to start recording time. The conical bottle mouth anti-evaporation device records the balance data every 10 seconds. Stop the measurement when the water flow rate obtained from the last 10 recorded data is constant.

[0020] Step 6: Remove the measured corn leaf and place it on the upper layer of the perforated partition. The bottom plate is filled with pure water wipes. Take a picture from directly above the perforated partition using a photographic device. Process the obtained image to obtain the area of ​​the corn leaf.

[0021] Place the corn leaf water potential control and area rapid measurement integrated unit containing corn leaves in a dark environment and allow the corn leaves to balance for about 20 minutes. Use an ultrasonic cleaner to cut 1cm wide corn leaves from the base of the leaves and place them in the corn leaf water potential control and area rapid measurement integrated unit to measure the water potential of the leaves. Then dry them and measure the dry weight. Fix the remaining corn leaves to the leaf fixing spiral silicone and connect them to the spiral silicone fixing connector. Record the reading of the balance at 0.01%.

[0022] Step 7: Calculate the hydraulic conductivity of the corn leaf;

[0023] Step 8: Calculate the degree of loss of hydraulic conductivity of corn leaves relative to the maximum hydraulic conductivity;

[0024] Step 9: Repeat steps 6 to 8. Stop measuring when the loss is greater than 50%, and dry and weigh the remaining leaves.

[0025] Step 10: Calculate the relative water content of corn leaves under different degrees of dehydration;

[0026] Step 11: Plot the graph of hydraulic conductivity and the corresponding water potential and relative water content of the leaf. If the number of points corresponding to hydraulic conductivity and water potential is too few or too many, the leaf drying time can be changed by analyzing the quantitative relationship between relative water content of the leaf and water potential to reduce or increase the leaf dehydration time.

[0027] Step 12: Fit the hydraulic conductivity embolism curve using different functional relationships, compare and analyze the fitting effects, and select the functional relationship with the best fitting effect.

[0028] Optionally, the specific formula for calculating the hydraulic conductivity of corn leaves is as follows:

[0029] K leaf =-v i / (S i ·ψ i )

[0030] In the formula, K leaf For hydraulic conductivity, v i S represents the water flow velocity. i Let ψ be the area of ​​the corn leaf. i The force of the water.

[0031] Optionally, the specific formula for calculating the loss of hydraulic conductivity of corn leaves relative to their maximum hydraulic conductivity is as follows:

[0032] PLC = 100 × (1 - K) leafi / K max )

[0033] In the formula, PLC represents the degree of loss, and K represents the loss level. leaf For hydraulic conductivity, K max This represents the maximum hydraulic conductivity.

[0034] Optionally, the specific formula for calculating the relative water content of corn leaves under different degrees of dehydration is as follows:

[0035] RWC i =[M i -M i+1 -mi] / [MM i+1 -m i -m i-1 -…-m]*100%

[0036] In the formula, RWC i M represents the relative water content of the leaves. i m is the weight of the remaining leaves after drying. i The dry weight after the water potential is measured.

[0037] Optionally, fitting the hydraulic conductivity embolism curve using different functional relationships specifically includes:

[0038] Linear function: K leaf =aψ leaf +b

[0039] S-shaped function:

[0040] Logical functions:

[0041] Exponential function:

[0042] In the formula, K leaf For hydraulic conductivity, ψ leaf Let be the corresponding blade water potential, and a, b, x0, and y0 be the fitting parameters of the function.

[0043] The technical effects of this invention are as follows:

[0044] The system and method provided by this invention are not only applicable to the determination of the maximum hydraulic conductance and embolism curve of maize leaves throughout the entire growth period, but also can achieve the goal of simultaneously measuring the maximum hydraulic conductance and complete embolism curve of maize leaves using only one maize leaf. This invention not only avoids the mechanical damage to leaves caused by leaf heterogeneity at different locations and pressure chamber method, but also makes the measured maximum hydraulic conductance and embolism curve fit better. Attached Figure Description

[0045] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0046] The accompanying drawings, which form part of this application, are used to provide a further understanding of this application. The illustrative embodiments and descriptions of this application are used to explain this application and do not constitute an undue limitation of this application. In the drawings:

[0047] Figure 1 This is a schematic diagram of the measurement system structure in an embodiment of the present invention;

[0048] Figure 2 This is a schematic diagram of the spiral silicone fixing joint in an embodiment of the present invention;

[0049] Figure 3 This is a schematic diagram of the structure of the angle adjustment joint bayonet device for adjusting corn leaves in an embodiment of the present invention;

[0050] Figure 4 This is a schematic diagram of the structure of the device for measuring water potential balance, dehydration, and leaf area of ​​corn leaves in an embodiment of the present invention.

[0051] Labeling Explanation: 1. Plant grow light; 2. Glass container; 3. Water circulation cooling device; 4. Adjustable bracket; 5. Spiral silicone for leaf fixing; 6. Spiral silicone fixing connector; 7. Bayonet device; 8. Perforated plate; 9. Exhaust valve; 10. Hose; 11. 0.001% balance; 12. Glass tube; 13. Iron stand; 14. Conical flask; 15. Conical flask mouth anti-evaporation device; 16. PC end; 17. Ultrasonic cleaner; 18. Ultrasonic cleaning machine; 19. Scalpel; 20. Beaker. Detailed Implementation

[0052] Various exemplary embodiments of the present invention will now be described in detail. This detailed description should not be considered as a limitation of the present invention, but rather as a more detailed description of certain aspects, features, and embodiments of the present invention.

[0053] It should be understood that the terminology used in this invention is merely for describing particular embodiments and is not intended to limit the invention. Furthermore, with respect to numerical ranges in this invention, it should be understood that each intermediate value between the upper and lower limits of the range is also specifically disclosed. Every smaller range between any stated value or intermediate value within a stated range, and any other stated value or intermediate value within said range, is also included in this invention. The upper and lower limits of these smaller ranges may be independently included or excluded from the range.

[0054] Various modifications and variations can be made to the specific embodiments described in this specification without departing from the scope or spirit of the invention, as will be apparent to those skilled in the art. Other embodiments derived from this specification will also be obvious to those skilled in the art. This application specification and embodiments are merely exemplary.

[0055] The terms “include,” “including,” “have,” “contain,” etc., used in this article are all open-ended terms, meaning that they include but are not limited to.

[0056] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. This application will now be described in detail with reference to the accompanying drawings and embodiments.

[0057] like Figure 1 - Figure 4 As shown, this embodiment provides a system for measuring the hydraulic conductivity and embolism curve of maize leaves based on the transpiration-driven method, including:

[0058] The transpiration measurement unit includes an induced evaporation module, an instantaneous transpiration measurement module, and a data recording module. The induced evaporation module includes an adjustable support, with a plant growth lamp mounted on the upper part of the support. A glass container is positioned below the plant growth lamp, and a water circulation cooling device is installed inside the glass container. A support plate is mounted on the lower part of the adjustable support, and the support plate has several through holes. A bayonet device is installed on the support plate, and a spiral silicone fixing connector is installed at the end of the bayonet device away from the support plate. A blade is installed inside the spiral silicone fixing connector to fix the spiral silicone. The instantaneous transpiration measurement module includes a 0.001% balance and a conical flask located above the balance. An iron stand is also provided on the balance, and a glass tube is movably mounted on the iron stand. The glass tube is connected to the spiral silicone fixing connector via a flexible hose. The 0.001% balance is connected to the data recording module.

[0059] The integrated unit for water potential regulation and rapid area measurement of maize leaves includes a cover, a perforated partition and a base plate that are fitted together from top to bottom.

[0060] The measurement system also includes a dew point potential meter for measuring the water potential of maize leaves.

[0061] This embodiment optimizes the design of the environmental control device, leaf balancing and dehydration device, leaf area acquisition device, evaporation suppression device, leaf position control device, and leaf area acquisition device to achieve rapid and accurate measurement of the hydraulic conductivity and embolism curve of corn leaves.

[0062] To achieve the above objectives, this embodiment provides a system for measuring the hydraulic conductivity and embolism curve of maize leaves based on the transpiration-driven method, comprising:

[0063] I. Apparatus for measuring corn leaf transpiration under steady-state conditions: 1. 200W LED plant growth lamp; 2. Glass container; 3. Water circulation cooling device inside the glass container; 4. Adjustable support; 5. Spiral silicone for fixing leaves; 6. Spiral silicone fixing connector; 8. Perforated plate for fixing leaf connectors; 7. Adjustable blade angle fixing device on perforated plate 8; 9. Exhaust valve; 10. 6mm diameter connecting hose; 11. 0.001g balance; 12. Hollow glass tube with an outer diameter of 5mm; 13. Iron stand; 14. 100ml conical flask; 15. Conical flask mouth transpiration suppression device; 16. PC end for continuous recording of balance weighing mass.

[0064] II. Convenient measurement device for leaf water potential balance, dehydration and leaf area: A device that can conveniently collect the leaf area of ​​corn and provide the leaf water potential balance environment and leaf dehydration environment.

[0065] III. Dew point potential meter;

[0066] IV. Other items used for processing or storing corn leaf samples: ultrasonic cleaner 18, scalpel 19 and 200ml beaker 20.

[0067] The device for measuring the transpiration of corn leaves under steady-state conditions includes a device for inducing stable evaporation of corn leaves under natural conditions, a device for measuring the instantaneous transpiration of corn leaves, and a device for recording balance data on a PC.

[0068] The device for inducing stable evaporation of corn leaves under simulated natural conditions includes a plant growth lamp 1, a glass container 2, a water circulation cooling device inside the glass container 3, an adjustable support 4, a spiral silicone leaf fixing device 5, a spiral silicone fixing connector 6, a bayonet device 7, and a perforated plate 8. The maximum photosynthetically active radiation of the LED plant growth lamp 1 is not less than 2000 μmol m² / s. -2 s -1 The glass container 2 is fixed to the uppermost part of the adjustable bracket 4 with screws, and is 2cm away from the bottom of the plant growth lamp 1. The glass container 2 is 5cm high, 5mm thick, and has a liquid depth of 3cm. The inlet and outlet of the water circulation cooling device 3 inside the glass container are located on the left and right sides of the glass container 2. The inlet (1cm from the liquid surface) and outlet (1cm lower than the inlet) are connected to the glass container 2 and distributed on both sides of the glass container 2. The water is circulated by a small pump (5V, 0.18A, 0.91W, 100L / H). The water heated by the plant growth lamp 1 enters the connecting pipe through the pump, is cooled, and then flows back. The adjustable bracket consists of three parts: upper, middle, and lower. The position of the screws can be adjusted to adjust the spiral silicone fixing joint 6 according to the height of the platform and the height of the plant growth lamp 1 and the glass container 2 from the corn leaves. The material is acrylic sheet. The leaf fixing spiral silicone 5 is made of ultra-soft silicone (such as... Figure 2As shown in the figure, the design method is to inscribe a circle with an inner diameter of 3cm, with the center of the circle as the center point, and the inner radius of 15mm and the outer radius of 25mm. The number of turns is designed as two spiral lines with zero height. Copy and rotate 180°, and with the center of the circle with a diameter of 3cm as the center point, draw a circle with a diameter of 5cm based on the two spiral curves. After trimming the part of the circle with a diameter of 3cm and 5cm that overlaps with the spiral line, stretch it to a thickness of 3cm. The spiral silicone fixing connector 6 is made of silicone, with an inner diameter of 20.5mm and a wall thickness of 2mm, and is tightened with a stainless steel tightening clamp. The bayonet device 7, fixed to the perforated plate 8, has one end fixed to the spiral silicone fixing connector 6 and the other end fixed to the perforated plate 8. The bayonet device 7 is connected in the middle with a screw, and the angle of the spiral silicone fixing connector 6 can be adjusted by the screw. The perforated plate 8 is made of acrylic sheet, with evenly distributed circular holes of 1cm in diameter and a center-to-center distance of 4cm between the holes. The exhaust valve 9 is located in the middle of the hose and is a three-way valve. It can be connected to an external syringe to eliminate air bubbles in the hose 10 and to inject water into the hose 10. The hose 10 has one end connected to the spiral silicone fixing connector 6 and the other end connected to the glass tube 12. The hose is made of transparent silicone and has a diameter of 6mm.

[0069] The aforementioned device for measuring instantaneous transpiration of leaves includes a 0.01% balance 11, a glass tube 12, an iron stand 13, a conical flask 14, and a conical flask mouth transpiration suppression device 15. The glass tube 12 is a hollow glass tube with an outer diameter of 5mm and a length of 30cm. The iron stand 13 is used to adjust and fix the glass tube 12 to a suitable position. The conical flask mouth transpiration suppression device 15 is made of acrylic sheet with a 5mm diameter hole in the center. It can be fixed at any position on the glass tube 12. The conical flask mouth transpiration suppression device 15 has a diameter of 5cm and an outermost extension of 2cm. When placing it, the position of the conical flask mouth transpiration suppression device 15 is adjusted so that it is located 1-2mm away from the conical flask mouth but not in contact with it.

[0070] The PC terminal 16, which records the balance data, is connected to the 1 / 10,000 balance 11 and can record the instantaneous reading of the 1 / 10,000 balance 11.

[0071] This embodiment also provides an integrated device for rapid measurement of corn leaf water potential regulation and area, which can conveniently collect corn leaf area and provide a leaf water potential balance environment and a corn leaf dehydration environment. It includes a cover with graduation lines, a perforated partition with holes, and a base plate (such as...). Figure 4(As shown). The lid, perforated partition, and base plate are all made of 100cm long, 15cm wide, and 2mm thick acrylic sheets. The lid and perforated partition, as well as the base plate and perforated partition, are fitted together for closure. The lid is 6mm from the top of the perforated partition, and the base plate is 6mm from the bottom of the perforated partition. The perforated partition has 2cm diameter holes, with the centers of the holes spaced 2.5cm apart, and the holes are evenly distributed on the partition. In use, place the corn leaves on the top of the partition, cover with the lid, and place a damp cloth or desiccant underneath to provide a humid, sealed environment for water potential balance of the corn leaves or a stable drying environment for dehydration. Alternatively, the base plate can be omitted, and a photo can be taken directly with a mobile phone. ImageJ software can then be used to process the image to obtain an accurate leaf area.

[0072] The dew point water potential meter is used to measure the water potential of corn leaves.

[0073] The measurement method provided in this embodiment specifically includes:

[0074] 1. Maintain an indoor environment that is windless, with an ambient temperature of 25℃ and no other significant disturbances.

[0075] 2. Preparation of degassed ultrapure water: Place the ultrapure water in an ultrasonic cleaner at 17 (maximum power) for 30 minutes to remove air bubbles from the ultrapure water.

[0076] 3. Preparation of Corn Samples: At least 2 hours after dark, select the corn plants to be measured. Using the base of the leaf at the measurement position as the center, cut off 10cm of the leafy stem. After bringing it back to the laboratory, use a scalpel and ultrasonic cleaner (18mm) to slowly cut open the corn leaves from the base, below the surface of degassed ultrapure water. Place the treated leaves in a container filled with 10-15cm of degassed ultrapure water and cover with a black plastic bag. Rehydrate for at least 5 hours.

[0077] 4. Turn on the plant growth lamp 1, pour pure water into the glass container 2, turn on the cooling circulation device 3 of the plant growth lamp, place the 100ml conical flask 14 on the balance 11, fix the glass tube 12 with the iron stand 13, pour an appropriate amount of degassed pure water into the conical flask 14, and submerge the lower end of the glass tube 12 3-4cm below the liquid surface in the conical flask 14. Adjust the height of the anti-evaporation device 15 at the mouth of the conical flask 14, maintaining it at 1-2mm. Place the spiral silicone fixing connector 6 below the degassed pure water liquid surface, connect the syringe with the exhaust valve 9 to fill the tubing with liquid, and close the switch on the spiral silicone fixing connector 6.

[0078] 5. Connect the 1 / 10,000 balance 11 and the conical bottle mouth anti-evaporation device 15 to ensure that the balance reading changes can be recorded normally.

[0079] 6. Take out a rehydrated corn leaf, weigh it (M), and quickly place it in a scalpel 19 containing 10cm of deaerated pure water. Place it on the perforated plate 8, adjust the height of the adjustable support 4 so that the plant growth light 1 and the glass container 2 are 10-20cm away from the tip of the leaf, and perform light induction on the corn leaf for at least 25 minutes.

[0080] 7. After the corn leaf has been photoinduced, quickly insert it into the spiral silicone fixing connector of the leaf fixing spiral silicone 5 underwater. Adjust the screw on the spiral silicone fixing connector 6 to ensure full contact between the leaf fixing spiral silicone 5 and the spiral silicone fixing connector 6. Adjust the perforated plate 8 to vent the hose. Fix the spiral silicone fixing connector 6 onto the bayonet device 7. Fix the bayonet device 7 in a suitable position on the perforated plate 8 and adjust the angle of the bayonet device 7 so that the tilt angle of the corn leaf is consistent with the growth state. Adjust the height of the perforated plate 8 so that the water level at the center point of the bayonet device 7 is level with the 0.01% balance 11. At the same time, take out a new rehydrated leaf and place it on the perforated plate 8 for photoinduced light under the plant growth lamp 1 and the glass container 2.

[0081] 8. Adjust the adjustable bracket 4 to adjust the distance between the plant growth light 1, the glass container 2 and the corn leaves, and control the height to 10-20cm.

[0082] 9. Turn on the switch on the bayonet device 7 to start recording time. The conical bottle mouth anti-evaporation device 15 records the balance data every 10 seconds. Stop the measurement when the water flow velocity (v) obtained from the last 10 recorded data remains unchanged (or is stable).

[0083] 10. Remove the corn leaf to be measured and quickly place it on the upper layer of the perforated partition. The bottom plate is filled with a wet wipe of pure water. Take a picture of the corn leaf water potential control and area rapid measurement integrated device with your mobile phone directly above it, and process it with ImageJ software to obtain the area (S) of the corn leaf.

[0084] 11. Place the corn leaf into the integrated device for controlling water potential and rapidly measuring area of ​​corn leaves, which has a dryer on the bottom plate. After placing it in a dark environment for 3 minutes, place it in the integrated device for controlling water potential and rapidly measuring area of ​​corn leaves, which has a wet towel on the bottom plate, for 20 minutes to balance. Take out the corn leaf and weigh it (M1). Cut a 1cm wide piece of corn leaf from the base of the corn leaf underwater using an ultrasonic cleaner 18, and put it into the integrated device for controlling water potential and rapidly measuring area of ​​corn leaves to measure the water potential (ψ1). Then dry it and measure the dry weight (m1). At the same time, quickly fix the remaining corn leaf onto the leaf fixing spiral silicone 5 and connect it to the spiral silicone fixing connector 6. Start recording the reading (v1) of the balance 11 at a ratio of 0.01% through the conical bottle mouth evaporation suppression device 15.

[0085] 12. Calculate K leafmax K leafmax=-v / (S·ψK) leafmax ).

[0086] 13. Calculate the hydraulic conductivity K of the corn leaf using the data from each measurement. leaf =-v i / (S i ·ψ i (v: mmol / s; S: m) 2 ; ψ: MPa; K: (μmol m- 2 s- 1 MPa); i = 1, 2, 3…). Where, K leaf For hydraulic conductivity, v i S represents the water flow velocity. i Let ψ be the area of ​​the corn leaf. i For water flow;

[0087] 14. Calculate the hydraulic conductivity (K) of maize leaves. leaf ) relative to the maximum hydraulic conductivity (K max The degree of loss (%) is calculated using the formula: PLC = 100 × (1 - K) leafi / K max ), i = 1, 2, 3...

[0088] 15. Repeat steps 10, 11, 12, 13, and 14. Stop the measurement when the latest calculated PLC value is greater than 50%, and dry and weigh the remaining blades (M). i+1 ).

[0089] 16. Calculate the relative water content (RWC) of corn leaves under different degrees of dehydration. i =[M i -M i+1 -mi] / [MM i+1 -m i -m i-1 -…-m]*100%.

[0090] 17. Plot the graphs of hydraulic conductivity K, corresponding water potential ψ, and corresponding relative water content RWC of the leaf, and analyze the relationship between them. If the number of points corresponding to K and ψ is too small or too large, the leaf drying time can be changed by analyzing the quantitative relationship between RWC and ψ to reduce or increase the leaf dehydration time.

[0091] 18. Fit the hydraulic conductivity embolism curve using four different functional relationships:

[0092] Linear function: K leaf =aψ leaf +b

[0093] S-shaped function:

[0094] Logical functions:

[0095] Exponential function:

[0096] In the formula, K leaf For hydraulic conductivity, ψ leaf Let be the corresponding blade water potential, and a, b, x0, and y0 be the fitting parameters of the function.

[0097] 19. Compare and analyze the fitting effects of the four hydraulic conductivity embolism curves in step 18, and select the function relationship with the best fitting effect to fit the other data.

[0098] This embodiment solves the problems of maize leaves being difficult to fix due to the lack of petioles, the impact of LED light source cooling fans on the measurement environment, errors caused by the evaporation of liquid in the bottle on the balance, individual differences between different maize leaves, unstable leaf equilibrium water potential and dehydration environment, unreasonable leaf placement, cumbersome leaf area measurement, and large sampling volume. It realizes the measurement of maize leaves throughout the entire growth period, eliminates experimental errors caused by individual differences in maize leaves, reduces the impact of the environment on maize leaves, and is suitable for the rapid and accurate measurement of hydraulic conductivity and embolism curves of maize leaves.

[0099] The above description is merely a preferred embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A system for measuring the hydraulic conductivity and embolism curve of maize leaves, characterized in that, include: The transpiration measurement unit includes an induced evaporation module, an instantaneous transpiration measurement module, and a data recording module. The induced evaporation module includes an adjustable bracket (4). A plant growth lamp (1) is installed on the upper part of the adjustable bracket (4). A glass container (2) is placed below the plant growth lamp (1). A water circulation cooling device (3) is installed inside the glass container (2). A support plate is installed on the lower part of the adjustable bracket (4). Several through holes are opened on the support plate. A bayonet device (7) is installed on the support plate. The bayonet device (7) is located away from the support plate. A spiral silicone fixing connector (6) is installed at one end of the plate, and a blade fixing spiral silicone (5) is provided inside the spiral silicone fixing connector (6); the instantaneous evapotranspiration measurement module includes a balance (11) of 1 / 10,000 and a conical flask (14) located above the balance (11), and an iron stand (13) is also provided on the balance (11), and a glass tube (12) is movably installed on the iron stand (13); the glass tube (12) is connected to the spiral silicone fixing connector (6) through a flexible tube (10); the balance (11) of 1 / 10,000 is connected to the data recording module; The integrated unit for water potential regulation and rapid area measurement of corn leaves includes a cover, a perforated partition and a base plate that are fitted together from top to bottom. The measurement system also includes a dew point potential meter for measuring the water potential of maize leaves.

2. The system according to claim 1, characterized in that, A conical bottle mouth evaporation suppression device (15) is installed on the wall of the glass tube (12), and the conical bottle mouth evaporation suppression device (15) corresponds to the position of the conical bottle (14).

3. The system according to claim 1, characterized in that, An exhaust valve (9) is installed on the hose (10).

4. The system according to claim 1, characterized in that, The lid has graduation lines.

5. The system according to claim 1, characterized in that, The perforated partition has several through holes.

6. A method for determining the hydraulic conductivity and embolism curve of maize leaves, applied to the maize leaf hydraulic conductivity and embolism curve determination system according to any one of claims 1-5, characterized in that, include: Step 1: Prepare the experimental environment and prepare degassed ultrapure water; Step 2: Obtain corn leaves and dissect and rehydrate them; Step 3: Turn on the plant growth lamp (1), inject pure water into the glass container (2), turn on the cooling circulation device, place the conical flask (14) on the balance (11), fix the glass tube (12) with the iron stand (13), inject the preset dose of degassed pure water into the conical flask (14), submerge the lower end of the glass tube (12) 3-4 cm below the liquid surface of the conical flask (14), adjust the height of the evaporation suppression device (15) at the mouth of the conical flask (14) to 1-2 mm, place the spiral silicone fixing connector (6) below the degassed pure water liquid surface, connect the syringe with the exhaust valve (9), fill the tubing (10) with liquid, turn off the switch on the spiral silicone fixing connector (6), and connect the balance (11) and the data recording module. Step 4: Take out a rehydrated corn leaf, weigh it, and place it on the support plate. Adjust the height of the adjustable bracket (4) so ​​that the plant growth lamp (1) and glass container (2) are 10-20cm away from the top of the leaf. Perform light induction treatment on the corn leaf. Step 5: Take out the corn leaves after the light-induced treatment, and insert them into the spiral silicone fixing connector (6) of the leaf fixing spiral silicone (5) under the water surface. Adjust the spiral silicone fixing connector (6) so that the leaf fixing spiral silicone (5) and the spiral silicone fixing connector (6) are in full contact. Adjust the support plate to vent the hose (10). Fix the spiral silicone fixing connector (6) on the bayonet device (7). Fix the bayonet device (7) on the support plate and adjust the angle of the bayonet device (7) so that the tilt angle of the corn leaves is consistent with the growth state. Adjust the height of the support plate so that the water surface height of the center point of the bayonet device (7) is level with the 1 / 10,000 balance (11). At the same time, take out the next rehydrated leaf and place it on the support plate for light-induced treatment under the plant growth lamp (1) and glass container (2). Turn on the switch on the bayonet device (7) and start recording time. The conical bottle mouth anti-evaporation device (15) records the balance data every 10 seconds. Stop the measurement when the water flow rate obtained from the last 10 recorded data remains unchanged. Step 6: Remove the measured corn leaf and place it on the upper layer of the perforated partition. The bottom plate is filled with pure water wipes. Take a picture from directly above the perforated partition using a photographic device. Process the obtained image to obtain the area of ​​the corn leaf. Place the corn leaf water potential control and area rapid measurement integrated unit containing corn leaves in a shaded environment and allow the corn leaves to balance for about 20 minutes. Use an ultrasonic cleaner (18) to cut a 1cm wide corn leaf from the base of the corn leaf, put it into the corn leaf water potential control and area rapid measurement integrated unit to measure the water potential of the leaf, and then dry it to measure the dry weight. Fix the remaining corn leaves to the leaf fixing spiral silicone (5) and connect it to the spiral silicone fixing connector (6). Record the reading of the balance (11) of 1 / 10,000. Step 7: Calculate the hydraulic conductivity of the corn leaf; Step 8: Calculate the degree of loss of hydraulic conductivity of corn leaves relative to the maximum hydraulic conductivity; Step 9: Repeat steps 6 to 8. Stop measuring when the loss is greater than 50%, and dry and weigh the remaining leaves. Step 10: Calculate the relative water content of corn leaves under different degrees of dehydration; Step 11: Plot the graph of hydraulic conductivity and the corresponding water potential and relative water content of the leaf. If the number of points corresponding to hydraulic conductivity and water potential is too few or too many, the leaf drying time can be changed by analyzing the quantitative relationship between relative water content of the leaf and water potential to reduce or increase the leaf dehydration time. Step 12: Fit the hydraulic conductivity embolism curve using different functional relationships, compare and analyze the fitting effects, and select the functional relationship with the best fitting effect.

7. The method according to claim 6, characterized in that, The specific formula for calculating the hydraulic conductivity of corn leaves is as follows: K leaf =-v i / (S i ·ψ i ) In the formula, K leaf For hydraulic conductivity, v i S represents the water flow velocity. i Let ψ be the area of ​​the corn leaf. i The force of the water.

8. The method according to claim 6, characterized in that, The specific formula for calculating the loss of hydraulic conductivity of corn leaves relative to their maximum hydraulic conductivity is as follows: PLC=100×(1-K leafi / K max ) In the formula, PLC represents the degree of loss, and K represents the loss level. leaf For hydraulic conductivity, K max This represents the maximum hydraulic conductivity.

9. The method according to claim 6, characterized in that, The specific formula for calculating the relative water content of corn leaves under different degrees of dehydration is as follows: RWC i =[M i -M i+1 -mi] / [M-M i+1 -m i -m i-1 -…-m]*100% In the formula, RWC i M represents the relative water content of the leaves. i m is the weight of the remaining leaves after drying. i The dry weight after the water potential is measured.

10. The method according to claim 6, characterized in that, The fitting of the hydraulic conductivity embolism curve using different functional relationships specifically includes: Linear function: K leaf =aψ leaf +b S-shaped function: Logical functions: Exponential function: In the formula, K leaf For hydraulic conductivity, ψ leaf Let be the corresponding blade water potential, and a, b, x0, and y0 be the fitting parameters of the function.

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