A method for estimating functional phenotype of rice leaf

Abstract

The application discloses a kind of estimation methods of rice leaf function phenotype, comprising the following steps: first, based on the situation simulation of canopy radiation transfer model, the coupling relationship of the opening proportion q L With photosynthetically active radiation I is obtained;Second, based on the close mechanism of leaf chlorophyll fluorescence SIF and electron transport rate J, combined with the above coupling relationship, accurate estimation of rice leaf J is realized based on SIF observation;Finally, based on the principle of evolution optimality, combined with the mechanism of J and maximum carboxylation rate V cmax , the accurate estimation of rice leaf V cmax Is realized.Based on the coupling relationship of q L And I, relying on the mechanism of SIF and electron transport rate and maximum carboxylation rate, the accurate estimation of rice leaf function phenotype J and V cmax Is realized, and a new rice function phenotype estimation method is constructed.

Description

Technical Field

[0001] This invention relates to a novel method for estimating crop functional phenotypes, specifically a new high-precision estimation method for rice leaf functional phenotypes (electron transport rate and maximum carboxylation rate), belonging to the field of smart agriculture technology. Background Technology

[0002] Rice fixes CO2 and generates organic matter through photosynthesis, forming the basis of global rice production. At the leaf scale, the photosynthetic rate of rice mainly depends on two processes: carboxylation and electron transport. The two most important parameters are the electron transport rate J and the maximum carboxylation rate V. cmax Based on the photosynthesis model, J and V cmax The photosynthetic rate of rice leaves is one of the two important functional phenotypic traits in rice. Improving the electron transport rate and maximum carboxylation rate of rice leaves is key to increasing light energy utilization and is also crucial for increasing national rice yield in the future. Therefore, accurately estimating the electron transport rate and maximum carboxylation rate of rice leaves is essential for studying the potential capacity of rice photosynthesis and can provide fundamental support for rice breeding.

[0003] Currently regarding J and V cmax The estimation mainly employs a linear statistical model method. The core idea is to construct a correlation between SIF and J and V based on a large number of leaf fluorescence SIF observations using statistical methods. cmax A linear model is used to estimate both. However, numerous studies have demonstrated that SIF is related to J and V. cmax The mechanistic relationship between SIF and J and V is not linear, and estimations based on simple linear statistical relationships have significant biases and uncertainties. Therefore, it is necessary to develop SIF with J and V. cmax The nonlinear mechanism is connected, and J and V are realized on this basis. cmax High-precision estimation.

[0004] J and V are implemented based on SIF and nonlinear models. cmax The core issue in estimating this is how to quantitatively calculate the open ratio q of the optical system II. L This patent clarifies q based on the radiative transfer model. L Based on the exponential function relationship between J and photosynthetically active radiation (I), a model for estimating J and V based on SIF observations was constructed. cmax The nonlinear model realizes J and V cmax Accurate estimation. Summary of the Invention

[0005] The purpose of this invention is to provide a method for estimating the functional phenotypes (electron transport rate and maximum carboxylation rate) of rice leaves, so as to achieve high-precision estimation of the functional phenotypes of rice leaves.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0007] A method for estimating the functional phenotype of rice leaves, comprising the following steps:

[0008] S1: The open ratio q of constructing optical system II L Coupling relationship with photosynthetically active radiation I;

[0009] S2: Based on the above coupling relationship, the electron transport rate J is estimated based on chlorophyll fluorescence SIF;

[0010] S3: Estimation of the maximum carboxylation rate V based on the electron transport rate J cmax .

[0011] As a further preferred embodiment of this scheme, in step S1, simulation results of a typical rice ecosystem are generated based on the radiative transfer model, and the openness ratio q of photosystem II is constructed on this basis. L The relationship between photosynthetically active radiation (I) and exponential function.

[0012] As a further preferred embodiment of this scheme, in step S1, the opening ratio q L The steps for establishing the coupling relationship with photosynthetically active radiation I are as follows:

[0013] First, based on remote sensing data, the average leaf parameters of rice-growing areas were obtained; then, based on a radiative transfer model, the q values ​​of typical rice production systems under different light conditions were simulated. L The changes; finally, based on the exponential function on q L The coupling relationship with I is quantitatively fitted; the formula is as follows:

[0014] q L =0.2618·e -0.001276·I .

[0015] As a further preferred option of this scheme, the parameters of rice leaves obtained include, but are not limited to, leaf area index and chlorophyll content; the radiative transfer model used is the SCOPE model.

[0016] As a further preferred embodiment of this scheme, in step S2, based on the close mechanistic relationship between leaf chlorophyll fluorescence (SIF) and electron transport rate J, and combined with the above-mentioned coupling relationship, an accurate estimation of J in rice leaves is achieved based on SIF observation; wherein, the specific formula for estimating the electron transport rate J based on leaf chlorophyll fluorescence (SIF) is as follows:

[0017]

[0018] In the formula, SIF represents chlorophyll fluorescence observation, and NIRv and FPAR represent near-infrared reflectance and photosynthetically active radiation components, respectively, which can be obtained based on ground-based multispectral observations.

[0019] As a further preferred embodiment of this scheme, in step S3, based on the principle of evolutionary optimality, J is combined with the maximum carboxylation rate V. cmax The mechanism link to achieve V in rice leaves cmax Accurate estimation; among which, V based on the principle of optimality. cmax The calculation formula is:

[0020]

[0021] In the formula, Where C i Γ represents the intercellular CO2 concentration. * K is the CO2 compensation point. m It is a constant.

[0022] The beneficial effects of this invention are: Based on SIF observations, this invention achieves high-precision estimation of functional phenotypes (electron transport rate and maximum carboxylation rate) in rice leaves. Compared with the original linear model method, the new method of this invention can effectively improve V cmax The high accuracy of the estimation is beneficial for systematically describing the changes in rice functional phenotypes and their responses to environmental factors, and helps to accurately assess and predict national rice yield. Attached Figure Description

[0023] Figure 1 For q L The fitting formula for I, where the X-axis represents photosynthetically active radiation I, in units of W / m². 2 The Y-axis is q L (No unit)

[0024] Figure 2 The graph shows the J calculation results based on this invention (line graph), where the X-axis represents the accumulated days of the year, and the Y-axis represents J and SIF, with units of μmol / m², respectively. -2 s -1 mWm -2 nm -1 sr -1 .

[0025] Figure 3 Based on the present invention V cmax Calculation results (line graph), where the X-axis represents the accumulated days of the year, and the Y-axis represents the volume of days. cmax The unit is μmolm -2 s -1 The two broken lines in the figure represent the estimated and observed results, respectively.

[0026] Figure 4 Based on the present invention V cmax Calculation results (scatter plot), where the X-axis represents the observed V. cmax The Y-axis represents the estimated V. cmax The units are all μmol / m -2 s -1 The straight line in the figure represents the estimated V. cmax With observation V cmax The linear fitting relationship. Detailed Implementation

[0027] The technical solution of the present invention will be further described below with reference to specific embodiments.

[0028] A method for estimating the functional phenotype of rice leaves, which is used in constructing q L Based on the coupling relationship with I, and relying on the mechanistic link between SIF observations and electron transport rate and maximum carboxylation rate, the J and V of rice leaves were realized. cmax The model provides an accurate estimate and compares the accuracy of nonlinear and linear estimates. The detailed model construction process is described below:

[0029] 1) Constructing the open ratio q of optical system II L Coupling relationship with photosynthetically active radiation I;

[0030] First, based on remote sensing data, the average leaf parameters of rice-growing areas worldwide were obtained; then, based on the SCOPE radiative transfer model, the q values ​​of typical rice production systems under different light conditions were simulated. L The changes; finally, based on the exponential function on q L The coupling relationship with I is quantitatively fitted, and the formula is: q L =0.2618·e -0.001276·I .

[0031] 2) Estimation of electron transport rate J based on chlorophyll fluorescence SIF;

[0032] Based on the close mechanistic relationship between leaf chlorophyll fluorescence (SIF) and electron transport rate (J), and combining the above coupling relationship, accurate estimation of J in rice leaves is achieved based on SIF observations. The specific formula for estimating electron transport rate J based on leaf chlorophyll fluorescence (SIF) is as follows:

[0033]

[0034] In the formula, SIF represents chlorophyll fluorescence observation, and NIRv and FPAR represent near-infrared reflectance and photosynthetically active radiation components, respectively, which can be obtained based on ground-based multispectral observations.

[0035] 3) Estimating the maximum carboxylation rate V based on the electron transport rate Jcmax ;

[0036] Based on the principle of evolutionary optimality, and combining J with the maximum carboxylation rate (V) cmax The mechanism of ) is related to the realization of V in rice leaves. cmax Accurate estimation; among which, V based on the principle of optimality. cmax The calculation formula is:

[0037]

[0038] In the formula, Where C i Γ represents the intercellular CO2 concentration. * K is the CO2 compensation point. m It is a constant.

[0039] 4) Comparison of the accuracy of nonlinear calculation results with linear calculation results.

[0040] V above cmax The accuracy of the nonlinear calculation results was compared with that of the linear calculation results, using the square of the correlation coefficient (R²). 2 The mean absolute error (MAE) and root mean square error (RMSE) are used as evaluation criteria.

[0041] Table 1. Comparison of accuracy between nonlinear and linear calculation results.

[0042]

[0043] As can be seen from Table (1), compared with the calculation results of the linear method, the nonlinear estimation method of rice functional phenotype (maximum carboxylation rate) based on fluorescence observation can significantly improve V cmax The estimation accuracy is improved. The root mean square error of the nonlinear method is 38.48% higher than that of the linear method.

[0044] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the above embodiments do not limit the scope of protection of the present invention in any way, and all technical solutions obtained by equivalent substitution or other means fall within the scope of protection of the present invention.

[0045] All parts not covered in this invention are the same as or can be implemented using existing technologies.

Claims

1. A method for estimating the functional phenotype of rice leaves, characterized in that... Includes the following steps: S1: The open ratio q of constructing optical system II L Coupling relationship with photosynthetically active radiation I; Based on the radiative transfer model, simulation results of a typical rice ecosystem were generated. On this basis, the openness ratio q of photosystem II was constructed. L The exponential function relationship between photosynthetically active radiation (I) and radiation. The specific steps for establishing the coupling relationship are as follows: First, based on remote sensing data, the average leaf parameters of rice-growing areas were obtained; then, based on a radiative transfer model, the q values ​​of typical rice production systems under different light conditions were simulated. L The changes; finally, based on the exponential function on q L The coupling relationship with I is quantitatively fitted; the formula is as follows: q L =0.2618·e -0.001276·I ; S2: Combining the above coupling relationship, the electron transport rate J is estimated based on chlorophyll fluorescence SIF; the specific formula for estimating the electron transport rate J based on leaf chlorophyll fluorescence SIF is as follows: In the formula, SIF represents chlorophyll fluorescence observation, and NIRv and FPAR represent near-infrared reflectance and photosynthetically active radiation components, respectively, which can be obtained based on ground-based multispectral observations. S3: Estimation of the maximum carboxylation rate V based on the electron transport rate J cmax .

2. The method for estimating the functional phenotype of rice leaves according to claim 1, characterized in that, Rice leaf parameters, including leaf area index and chlorophyll content, were obtained; the radiative transfer model used was the SCOPE model.

3. The method for estimating the functional phenotype of rice leaves according to claim 1, characterized in that: In step S3, based on the principle of evolutionary optimality, J is combined with the maximum carboxylation rate V. cmax The mechanism link to achieve V in rice leaves cmax Accurate estimation; among which, V based on the principle of optimality. cmax The calculation formula is: In the formula, Where C i Γ represents the intercellular CO2 concentration. * K is the CO2 compensation point. m It is a constant.

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