Method for determining carbon dioxide response characteristics of photosynthetic rate in plants

Abstract

The present invention discloses a method for measuring the carbon dioxide response characteristics of plant population photosynthetic rate, which includes performing closed-loop detection on the photosynthesis of a plant population in an isolation container, and recording the corresponding detection time point, the measured CO2 concentration, the pressure and temperature in the isolation container, and drawing a trend graph of the CO2 concentration value changing over time and a trend line fitting based on the measured data; selecting a number of data points on the fitted trend line for derivation, calculating the trend line slope k at the selected point position, importing the slope k of the corresponding data point, the pressure, the volume of the isolation container and the plant area into a population photosynthesis calculation model, and calculating the population photosynthetic rate; drawing a carbon dioxide response curve of the plant population photosynthetic rate based on the obtained population photosynthetic rate and the corresponding CO2 concentration. The method of the present invention can accurately measure the relationship between the plant population photosynthetic rate and the CO2 concentration, and the method can be applied to the plant variety breeding process to help select plant varieties with high light efficiency.

Description

Technical Field

[0001] The present invention relates to the technical field of photosynthesis, and in particular to a method for determining the relationship between the photosynthetic rate of a plant population and the concentration of carbon dioxide. Background Art

[0002] The photosynthesis of a single plant or a group of plants is called plant photosynthesis. The group photosynthetic rate measures the photosynthetic carbon assimilation capacity of a plant per unit area of ​​land or per unit area of ​​plant leaves. Compared to individual leaves, the group photosynthetic rate more accurately reflects the photosynthetic capacity of a plant and has a more direct and significant regulatory effect on plant yield. Plant photosynthesis requires carbon dioxide, but the relationship between the group photosynthesis rate and the carbon dioxide concentration in the plant's surrounding environment remains under investigation. Summary of the Invention

[0003] In view of this, the purpose of the present invention is to provide a method for measuring the carbon dioxide response characteristics of plant population photosynthetic rate, so as to solve the technical problem of accurately measuring the relationship between the photosynthetic rate of plant population and carbon dioxide concentration.

[0004] The method for determining the carbon dioxide response characteristics of plant population photosynthetic rate of the present invention comprises the following steps:

[0005] 1) Place the test plant population in an isolation container, and allow outside air to enter the isolation container while simultaneously discharging the gas in the isolation container to the outside environment, so that the isolation container forms a stable air intake and exhaust;

[0006] 2) Light-induce the plant population and record the CO2 concentration, temperature, and pressure in the isolation container;

[0007] 3) After the CO2 concentration in the isolation container stabilizes, carbon dioxide gas is injected into the isolation container to rapidly raise the CO2 concentration in the isolation container to the required range, and then the air inlet and exhaust port of the isolation container are closed to form a closed space;

[0008] 4) Conducting a closed-loop test of the photosynthesis of the plant population in the isolation container: Using an air pump, extract the gas from the isolation container and send it into a photosynthesis detector. Return the gas discharged from the photosynthesis detector to the isolation container. During the detection process of the photosynthesis detector, the corresponding detection time point, the measured CO2 concentration, the pressure and temperature in the isolation container are recorded. The closed-loop test continues until the CO2 concentration stabilizes.

[0009] 5) Based on the CO2 concentration and the corresponding time obtained in step 4), a trend graph of the CO2 concentration value changing over time is drawn, and a trend line is fitted for the CO2 concentration from the maximum value to the minimum value;

[0010] 6) Select several data points on the fitted trend line and perform derivative calculation to calculate the slope k of the trend line at the selected points. The absolute value of the slope k is the CO2 decrease rate per unit time.

[0011] 7) Importing the slope k of the corresponding data point, the pressure within the isolation container, the volume of the isolation container, and the plant area into a population photosynthesis calculation model to calculate the population photosynthetic rate; the plant area is the actual area occupied by the plant population or the sum of the areas of all leaves in the plant population;

[0012] 8) Based on the calculated group photosynthetic rate and the corresponding CO2 concentration, a carbon dioxide response curve of the plant group photosynthetic rate is drawn, that is, the response relationship between the plant group photosynthetic rate and the carbon dioxide concentration is obtained.

[0013] Furthermore, in step 3), carbon dioxide gas is injected into the isolation container to rapidly increase the CO2 concentration in the isolation container to above 2000 ppm.

[0014] Furthermore, in step 6), 20, 40, and 60 data points in the trend line are used for derivation to explore the optimal number of data points.

[0015] Beneficial effects of the present invention:

[0016] The method for measuring the carbon dioxide response characteristics of plant population photosynthetic rate of the present invention can accurately measure the relationship between the photosynthetic rate of the plant population and the CO2 concentration; during the plant cultivation process, the carbon dioxide response curve of the plant population photosynthetic rate obtained by this method can be used to regulate the CO2 concentration of the plant growth environment to promote the growth and development of the plants; in the work of plant variety breeding, the carbon dioxide response curve of the plant population photosynthetic rate obtained by this method can also be used to help select plant varieties with high light efficiency characteristics. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 The figure is a trend line graph showing the change of CO2 concentration over time after the experiment was performed according to the method described in the embodiment;

[0018] Figure 2 For Figure 1 Schematic diagram of the derivation of the data points on the fitted trend line;

[0019] Figure 3 This is the carbon dioxide response curve of the plant population photosynthetic rate, where A, B, and C are the calculation and graph of population photosynthesis using 20, 40, and 60 data points, respectively. DETAILED DESCRIPTION

[0020] The present invention will be further described below with reference to the accompanying drawings and examples.

[0021] The method for measuring the carbon dioxide response characteristics of plant population photosynthetic rate in this embodiment comprises the following steps:

[0022] 1) Place the test plant colony in an isolation container. By introducing outside air into the isolation container and simultaneously discharging the gas within the isolation container to the outside environment, the isolation container forms a stable air intake and exhaust. The isolation container can adopt the detection box disclosed in the utility model patent application number 202120876723.3, entitled "Artificial Simulation of Natural Light Plant Colony Gas Exchange Detection Box and Detection System"; of course, other types of isolation containers can also be used in different embodiments.

[0023] 2) Perform light induction on the plant population and record the CO2 concentration, temperature, and pressure in the isolation container.

[0024] 3) After the CO2 concentration in the isolation container stabilizes, carbon dioxide gas is filled into the isolation container to rapidly increase the CO2 concentration in the isolation container to above 2000 ppm, and then the air inlet and exhaust port of the isolation container are closed to form a closed space.

[0025] 4) Conduct closed-loop detection of the photosynthesis of the plant population in the isolation container: Use an air pump to extract the gas in the isolation container and send it into a photosynthesis detector, then send the gas discharged from the photosynthesis detector back into the isolation container, and record the corresponding detection time point, measured CO2 concentration, pressure and temperature in the isolation container during the detection process of the photosynthesis detector; the closed-loop detection continues until the CO2 concentration stabilizes.

[0026] 5) Based on the CO2 concentration and the corresponding time obtained in step 4), a trend graph of the CO2 concentration value changing with time is drawn, and a trend line is fitted for the CO2 concentration from the maximum value to the minimum value.

[0027] 6) Select several data points on the fitted trend line and take the derivative to calculate the slope k of the trend line at the selected point, k = dC / dt; the absolute value of the slope k is the CO2 decrease rate per unit time.

[0028] 7) The slope k of the corresponding data point, the pressure in the isolation container, the volume of the isolation container, and the plant area are introduced into a population photosynthesis calculation model to calculate the population photosynthetic rate; the plant area is the actual area occupied by the plant population or the sum of the areas of all leaves in the plant population.

[0029] 8) Based on the calculated group photosynthetic rate and the corresponding CO2 concentration, a carbon dioxide response curve of the plant group photosynthetic rate is drawn, that is, the response relationship between the plant group photosynthetic rate and the carbon dioxide concentration is obtained.

[0030] As an improvement to the above embodiment, in step 6), 20, 40, and 60 data points in the trend line are used for derivation to explore the optimal number of data points to be selected, thereby improving the accuracy of the carbon dioxide response curve of the photosynthetic rate of the plant population.

[0031] The carbon dioxide response characteristic experiment of the plant population photosynthetic rate was carried out according to the method described in the above embodiment. The experimental results showed that with the increase of CO2 concentration, the photosynthetic rate (CAP) of the plant population increased rapidly, especially in the range of 200-400 ppm, the rate of increase of the population photosynthetic rate was relatively high; when the CO2 concentration was higher than 400, the photosynthetic rate of the plant population still increased with the increase of CO2 concentration, but the growth rate of the photosynthetic rate of the plant population was lower than that in the CO2 concentration stage of 200-400 ppm.

[0032] Under different sampling point numbers, the more data points collected, the more accurate the population photosynthetic rate calculation and the smaller the data dispersion. Experimental results show that selecting 60 data points for population photosynthesis calculation is optimal. When measuring photosynthetic light response curves of large plant populations, a 60-point sampling mode can be selected under different CO2 concentration gradients to achieve both high measurement efficiency and accuracy.

[0033] Furthermore, the measurement and calculation of plant photosynthetic rates under different CO2 concentrations show that CO2 concentration has a significant effect on the photosynthetic rate of plant populations. Therefore, measuring plant photosynthetic rates under a unified environmental standard can better ensure the accuracy and comparability of measurements.

[0034] The method for measuring the carbon dioxide response characteristics of plant population photosynthetic rate described in this embodiment can accurately measure the relationship between the photosynthetic rate of a plant population and the CO2 concentration; during the plant cultivation process, the carbon dioxide response curve of the plant population photosynthetic rate obtained by this method can be used to regulate the CO2 concentration of the plant growth environment to promote the growth and development of the plants; in the plant variety breeding work, plant varieties with high light efficiency characteristics can also be selected based on the carbon dioxide response curve of the plant population photosynthetic rate obtained by this method.

[0035] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not limiting. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the purpose and scope of the technical solutions of the present invention, and should be included in the scope of the claims of the present invention.

Claims

1. A method for determining the carbon dioxide response characteristics of plant population photosynthetic rate, characterized by: The following steps are involved: 1) Place the test plant population in an isolation container, and allow outside air to enter the isolation container while simultaneously discharging the gas in the isolation container to the outside environment, so that the isolation container forms a stable air intake and exhaust; 2) Light-induce the plant population and record the CO2 concentration, temperature, and pressure in the isolation container; 3) After the CO2 concentration in the isolation container stabilizes, carbon dioxide gas is injected into the isolation container to rapidly raise the CO2 concentration in the isolation container to the required range, and then the air inlet and exhaust port of the isolation container are closed to form a closed space; 4) Conducting a closed-loop test of the photosynthesis of the plant population in the isolation container: Using an air pump, extract the gas from the isolation container and send it into a photosynthesis detector. Return the gas discharged from the photosynthesis detector to the isolation container. During the detection process of the photosynthesis detector, the corresponding detection time point, the measured CO2 concentration, the pressure and temperature in the isolation container are recorded. The closed-loop test continues until the CO2 concentration stabilizes. 5) Based on the CO2 concentration and the corresponding time obtained in step 4), a trend graph of the CO2 concentration value changing over time is drawn, and a trend line is fitted for the CO2 concentration from the maximum value to the minimum value; 6) Select several data points on the fitted trend line and perform derivative calculation to calculate the slope k of the trend line at the selected points. The absolute value of the slope k is the CO2 decrease rate per unit time. 7) Importing the slope k of the corresponding data point, the pressure within the isolation container, the volume of the isolation container, and the plant area into a population photosynthesis calculation model to calculate the population photosynthetic rate; the plant area is the actual area occupied by the plant population or the sum of the areas of all leaves in the plant population; 8) Based on the calculated group photosynthetic rate and the corresponding CO2 concentration, a carbon dioxide response curve of the plant group photosynthetic rate is drawn, that is, the response relationship between the plant group photosynthetic rate and the carbon dioxide concentration is obtained.

2. The method for determining the carbon dioxide response characteristics of plant population photosynthetic rate according to claim 1, wherein: In step 3), carbon dioxide gas is injected into the isolation container to rapidly increase the CO2 concentration in the isolation container to above 2000 ppm.

3. The method for determining the carbon dioxide response characteristics of plant population photosynthetic rate according to claim 1, wherein: In step 6), 20, 40, and 60 data points in the trend line are used for derivation to explore the optimal number of data points.

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