Method and device for estimating light energy utilization efficiency of plant canopy

Abstract

The invention provides a plant canopy light energy utilization efficiency estimation method and device. The method comprises the following steps: constructing a group canopy geometric model according to a multi-view RGB image sequence of a target plant; for each single plant three-dimensional model, the specific leaf nitrogen content of each leaf surface element is calculated according to the spectral reflectivity of the corresponding wave band of the leaf surface element, and the net photosynthetic rate of each leaf surface element under the saturated light intensity is calculated according to the specific leaf nitrogen content; calculating the average instantaneous net photosynthetic rate of each blade surface element according to the instantaneous photosynthetically active radiation intensity intercepted by the blade surface element; according to the average instantaneous net photosynthetic rate and the day-by-day cumulant of the PAR interception intensity on the population, the canopy day-by-day light energy utilization efficiency of the target plant is obtained for screening of high-photosynthetic-efficiency germplasm resources or varieties. According to the method, the calculation precision of the photosynthetic productivity of the canopy is improved through surface element scale light-nitrogen fusion, and the estimation accuracy and estimation efficiency of the light energy utilization efficiency of the field plot scale canopy are improved.

Description

Technical Field

[0001] The present invention relates to the field of agricultural information technology, and in particular to a method and a device for estimating plant canopy light energy utilization efficiency. Background Art

[0002] Crop canopy RUE (Radiation Use Efficiency) refers to the ratio of the accumulated dry matter of a crop during a certain growth period to the amount of photosynthetically active radiation intercepted by the canopy during that period. It is used to characterize the photosynthetically active radiation conversion efficiency of the crop. Since there is still a lot of room for improvement in crop canopy RUE from its theoretical upper limit, crop breeding for efficient use of light energy has become an important and feasible way to increase crop yields.

[0003] In related technologies, there are three main methods for estimating RUE of canopies of crops such as corn: (1) Eddy covariance technology, which continuously measures the CO2 exchange flux between the vegetation canopy and the atmosphere and the interception of PAR (Photosynthetically Active Radiation) by the vegetation canopy to obtain the RUE of the vegetation canopy. This method uses monitoring equipment with high purchase and maintenance costs and is not suitable for measurement at the scale of small plots. (2) Slope method: The crop biomass is obtained multiple times during the growth period, and the cumulative interception of crop canopy PAR is estimated by direct instrument measurement or leaf area index. The slope of the linear regression model between the two is the RUE. If the sampling times are too small, the RUE will have a large error. Moreover, for crops with large differences in individual plant types, the above method is prone to overestimation of RUE if the heterogeneous distribution of PAR within the canopy is not considered. In addition, the growth period of crops is relatively long, so this method can only be used to evaluate the light energy utilization efficiency of new varieties, but cannot provide a reference for determining the plant type design goals before breeding. (3) Canopy photosynthetic model: using the methods of systems biology and computer simulation models to simulate crop photosynthetic production processes and predict their responses to the environment and management; this method simplifies the crop canopy into one or more large leaves, and only uses the extinction coefficient and nitrogen extinction coefficient to simulate the attenuation of photosynthetically active radiation and leaf nitrogen in the vertical direction downward along the canopy. This makes it difficult to reflect the heterogeneous distribution of the canopy in 3D space, limiting its application in the accurate quantitative evaluation of canopy light energy utilization efficiency. Summary of the invention

[0004] The present invention provides a method and device for estimating the light energy utilization efficiency of a plant canopy, so as to solve the problems of high cost and limited use scenarios when the prior art uses eddy covariance technology to estimate RUE; multiple biomass sampling is required when the slope method is used to estimate RUE, which is inefficient and prone to errors; and it is difficult to reflect the heterogeneous distribution law in the 3D space of the canopy when using a canopy photosynthesis model to estimate RUE, resulting in the defect of low RUE estimation accuracy. The method and device are used to improve the accuracy and efficiency of estimating the light energy utilization efficiency of the canopy at the scale of a field plot.

[0005] The present invention provides a method for estimating plant canopy light energy utilization efficiency, comprising: Constructing a group canopy geometry model based on a multi-view RGB image sequence of a target plant, wherein the group canopy geometry model includes a plurality of plant individual three-dimensional models, and each plant individual three-dimensional model includes a plurality of leaf face elements; For each plant three-dimensional model, the specific leaf nitrogen content SLN of each leaf element is calculated according to the spectral reflectance of the corresponding band of the leaf element, and the net photosynthetic rate of each leaf element under saturated light intensity is calculated according to SLN; Calculating the average instantaneous net photosynthetic rate of each leaf element according to the instantaneous photosynthetically active radiation PAR intensity intercepted by the leaf element and the net photosynthetic rate; According to the average instantaneous net photosynthetic rate and the daily cumulative amount of PAR interception intensity in the population, the daily light energy utilization efficiency of the canopy of the target plant is obtained for the screening of high-light-efficiency germplasm resources or varieties; wherein the daily cumulative amount of PAR interception intensity in the population is determined based on the photosynthetically active radiation interception intensity of each leaf element, and the photosynthetically active radiation interception intensity is determined based on the daily radiation data of the target plant and the area of ​​each leaf element.

[0006] According to a method for estimating plant canopy light energy utilization efficiency provided by the present invention, the specific leaf nitrogen content SLN of each leaf element is calculated according to the spectral reflectance of the corresponding band of the leaf element, which includes: The hyperspectral vegetation index CCCI is calculated based on the spectral reflectance of each band of the leaf surface element; Linear regression calculation is performed based on CCCI to obtain the relative chlorophyll content SPAD of each leaf element, and the SLN is calculated based on the SPAD.

[0007] According to a method for estimating plant canopy light energy utilization efficiency provided by the present invention, the method of calculating the average instantaneous net photosynthetic rate of each leaf element according to the instantaneous photosynthetically active radiation PAR intensity intercepted by the leaf element comprises: Calculating light distribution according to the group canopy geometry model and the daily radiation data to obtain the area of ​​each leaf element and the interception amount of photosynthetically active radiation; Calculating the photosynthetically active radiation interception intensity of each leaf element according to the area of ​​the leaf element and the photosynthetically active radiation interception amount; The average instantaneous net photosynthetic rate is determined based on the light response curve model according to the net photosynthetic rate of each leaf element under saturated light intensity and the photosynthetically active radiation interception intensity.

[0008] According to a method for estimating plant canopy light energy utilization efficiency provided by the present invention, the daily light energy utilization efficiency of the canopy of the target plant is obtained according to the daily accumulation of the average instantaneous net photosynthetic rate and the PAR interception intensity in the population, including: Obtaining the net assimilation of CO2 of each leaf element according to the area of ​​the leaf element and the average instantaneous net photosynthetic rate; Calculate the instantaneous photosynthetic rate of the plant single plant three-dimensional model according to the net CO2 assimilation of each leaf element, and then calculate the daily CO2 assimilation of the group according to the instantaneous photosynthetic rate corresponding to each plant single plant three-dimensional model; Calculate the daily dry matter accumulation of the target plant population according to the daily CO2 assimilation of the population; The daily light energy utilization efficiency of the canopy is determined based on the ratio of the daily dry matter accumulation of the population to the daily cumulative amount of the PAR interception intensity in the population.

[0009] According to a method for estimating plant canopy light energy utilization efficiency provided by the present invention, constructing a group canopy geometric model based on a multi-view RGB image sequence of a target plant comprises: Performing three-dimensional reconstruction on the multi-view RGB image sequence to obtain three-dimensional point cloud data of the plant; The plant three-dimensional point cloud data is gridded, and the group canopy geometry model is constructed based on the gridded point cloud data using a t-distributed corn group three-dimensional model method; wherein multiple plant individual three-dimensional models in the group canopy geometry model are obtained by replicating a central target group around the reconstructed target group.

[0010] According to a method for estimating plant canopy light energy utilization efficiency provided by the present invention, the spectral reflectance of the corresponding band of the leaf surface element is obtained by the following steps: Collecting a multi-view RGB image sequence and a multi-view multi-spectral image sequence of the target plant; Performing three-dimensional reconstruction on the multi-view RGB image sequence to obtain three-dimensional colored point cloud data; performing mapping processing on the multi-view multi-spectral image sequence to the multi-view RGB image to obtain multi-spectral colored point cloud data; The three-dimensional colored point cloud data and the multi-spectral colored point cloud data are fused to obtain the multi-spectral point cloud data, and the spectral reflectance is extracted from the multi-spectral point cloud data.

[0011] The present invention also provides a plant canopy light energy utilization efficiency estimation device, comprising: A model building module, used to build a group canopy geometry model according to a multi-view RGB image sequence of a target plant, wherein the group canopy geometry model includes a plurality of plant individual three-dimensional models, and each plant individual three-dimensional model includes a plurality of leaf facets; The first calculation module is used to calculate the specific leaf nitrogen content SLN of each leaf element according to the spectral reflectance of the corresponding band of the leaf element for each plant three-dimensional model, and calculate the net photosynthetic rate of each leaf element under saturated light intensity according to the SLN; The second calculation module is used to calculate the average instantaneous net photosynthetic rate of each leaf element according to the instantaneous photosynthetically active radiation PAR intensity intercepted by the leaf element and the net photosynthetic rate; The third calculation module is used to obtain the daily light energy utilization efficiency of the canopy of the target plant according to the daily cumulative amount of the average instantaneous net photosynthetic rate and the PAR interception intensity in the population, so as to screen high-light-efficiency germplasm resources or varieties; wherein the daily cumulative amount of the PAR interception intensity in the population is determined based on the photosynthetically active radiation interception intensity of each leaf surface element, and the photosynthetically active radiation interception intensity is determined based on the daily radiation data of the target plant and the area of ​​each leaf surface element.

[0012] The present invention also provides an electronic device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein when the processor executes the computer program, any of the above-mentioned methods for estimating plant canopy light energy utilization efficiency is implemented.

[0013] The present invention also provides a non-transitory computer-readable storage medium on which a computer program is stored. When the computer program is executed by a processor, the method for estimating the light energy utilization efficiency of a plant canopy as described in any one of the above is implemented.

[0014] The present invention also provides a computer program product, comprising a computer program, wherein when the computer program is executed by a processor, the method for estimating the light energy utilization efficiency of a plant canopy as described in any one of the above is implemented.

[0015] The method and device for estimating the light energy utilization efficiency of plant canopies provided by the present invention construct a group canopy geometric model through a multi-view RGB image sequence of a target plant, calculate the specific leaf nitrogen content SLN of each leaf element according to the spectral reflectance of the corresponding band of the leaf element for each plant single plant three-dimensional model, and calculate the net photosynthetic rate (A) of each leaf element under saturated light intensity according to the SLN. max); the average instantaneous net photosynthetic rate of each leaf element is calculated based on the instantaneous photosynthetically active radiation (PAR) intensity intercepted by the leaf element; the daily light energy utilization efficiency of the canopy of the target plant is obtained based on the daily accumulation of the average instantaneous net photosynthetic rate and the PAR interception intensity in the population, so as to screen high-light-efficiency germplasm resources or varieties. The calculation accuracy of canopy photosynthetic productivity is improved by fusion of light and nitrogen at the element scale, and the accuracy and efficiency of estimating canopy light energy utilization efficiency at the field plot scale are improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0017] Figure 1 It is one of the flow charts of the method for estimating the light energy utilization efficiency of plant canopy provided by the present invention.

[0018] Figure 2 This is the second flow chart of the method for estimating plant canopy light energy utilization efficiency provided by the present invention.

[0019] Figure 3 It is a structural schematic diagram of a device for estimating plant canopy light energy utilization efficiency provided by the present invention.

[0020] Figure 4 It is a structural schematic diagram of the electronic device provided by the present invention. DETAILED DESCRIPTION

[0021] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in conjunction with the drawings of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0022] Combine the following Figure 1-Figure 3 The present invention describes a method and device for estimating plant canopy light energy utilization efficiency.

[0023] Figure 1 is one of the flow charts of the method for estimating the light energy utilization efficiency of plant canopy provided by the present invention, such as Figure 1 As shown, the method comprises the following steps: Step 110: construct a group canopy geometry model based on the multi-view RGB image sequence of the target plant, wherein the group canopy geometry model includes a plurality of plant individual three-dimensional models, and each plant individual three-dimensional model includes a plurality of leaf facets.

[0024] In this step, target plants include but are not limited to crops such as corn or sorghum.

[0025] In this step, the user can synchronously obtain the corn 3D plant type and leaf photosynthetic parameters through a professional camera or a crop single-plant pipeline phenotyping platform, that is, the above-mentioned multi-view RGB image sequence can be obtained through the crop single-plant pipeline phenotyping acquisition platform.

[0026] Step 120: for each plant single three-dimensional model, the specific leaf nitrogen content SLN of each leaf element is calculated according to the spectral reflectance of the corresponding band of the leaf element, and the net photosynthetic rate of each leaf element under saturated light intensity is calculated according to the SLN.

[0027] In this step, the average instantaneous net photosynthetic rate of each leaf element is obtained by analyzing the photosynthetic parameters of the leaf element of each plant three-dimensional model in the group canopy geometric model; Taking corn as an example, the average instantaneous net photosynthetic rate of the leaf element corresponding to the corn three-dimensional model can be achieved by the following steps: (1) The hyperspectral vegetation index (CCCI) is calculated based on the spectral reflectance of each band of the leaf surface element.

[0028] In this embodiment, the spectral reflectance of each band of each facet is extracted, and the CCCI spectral index is calculated using the following formula: ; The NDRE index is calculated using the following formula: ; in, R nir and R re Represent the reflectivity of the near-infrared and red-edge bands, respectively.

[0029] In this embodiment, the reflectivity of the near-infrared band and the reflectivity of the red-edge band can be extracted from the multi-spectral point cloud data of the plant.

[0030] Specifically, the spectral reflectance of the corresponding band of the leaf surface element is obtained through the following steps: collecting a multi-view RGB image sequence and a multi-view multi-spectral image sequence of the target plant; performing three-dimensional reconstruction on the multi-view RGB image sequence to obtain three-dimensional colored point cloud data; mapping the multi-view multi-spectral image sequence to the multi-view RGB image to obtain multi-spectral colored point cloud data; fusing the three-dimensional colored point cloud data and the multi-spectral colored point cloud data to obtain multi-spectral point cloud data, and extracting the spectral reflectance from the multi-spectral point cloud data.

[0031] (2) Linear regression calculation was performed based on CCCI to obtain the relative chlorophyll content SPAD of each leaf element, and SLN was calculated based on SPAD.

[0032] In this embodiment, the association between CCCI and SPAD is shown in Table 1 below: Table 1. Correlation between CCCI and SPAD of corn at different growth stages

[0033] In this embodiment, the specific leaf nitrogen content SLN (unit: g N m) of the leaf surface element is calculated by the following formula: -2 ): .

[0034] (3) Calculate the net photosynthetic rate of each leaf element under saturated light intensity based on SLN.

[0035] In this example, the net photosynthetic rate at the saturation light intensity of each bin is A max (Unit, μmol CO2m -2 s -1 ) can be calculated by the following formula: .

[0036] Step 130: Calculate the average instantaneous net photosynthetic rate of each leaf element based on the instantaneous photosynthetically active radiation PAR intensity and the net photosynthetic rate intercepted by the leaf element.

[0037] In this step, after obtaining the net photosynthetic rate of each leaf element under saturated light intensity, the photosynthetically active radiation interception intensity of each leaf element can be further calculated using the group canopy geometry model and the measured daily radiation data.

[0038] In this embodiment, there are two main ways to obtain daily radiation data: (1) collecting from national meteorological monitoring stations near the crops; (2) collecting from self-purchased automatic meteorological observation stations.

[0039] Specifically, (4) light distribution is calculated based on the group canopy geometry model and daily radiation data to obtain the area and photosynthetically active radiation interception of each leaf element; and the photosynthetically active radiation interception intensity of each leaf element is calculated based on the area and photosynthetically active radiation interception of the leaf element.

[0040] In this embodiment, the reconstructed 3D corn population grid model and daily radiation data are input into the light distribution calculation software Shine3DCrops, and the area of ​​each surface element is output ( L i,j,k , m 2 ) and photosynthetically active radiation interception ( PAR i,j,k,t , mmol).

[0041] In this embodiment, the photosynthetically active radiation interception intensity I i,j,k,t (Unit, μmol m -2 s -1 ) can be calculated by the following formula: ; Among them, the i Plant j The first leaf k The area of ​​a face is L i,j,k , which is in t The cumulative intercepted PAR in the hour is PAR i,j,k,t (Unit, mmol h -1 ).

[0042] (5) The average instantaneous net photosynthetic rate is determined based on the net photosynthetic rate of each leaf element and the intercepted photosynthetic active radiation intensity based on the light response curve model.

[0043] In this embodiment, the above I i,j,k,t Substituting into the light response curve model, we can get i Plant j The leaves are t Average instantaneous net photosynthetic rate per hour A i,j,k,t (Unit, μmol m -2 s -1 ), calculated as follows: ; in, α is the apparent quantum efficiency (can be set to 0.05), θ Empirical parameters that determine the shape of the curve (can be set according to actual user needs, for example, θis 0.8), A max,i,j,k For leaves i The net photosynthetic rate under saturated light intensity is calculated from the above-mentioned leaf element photosynthetic phenotypic parameter analysis part.

[0044] In this embodiment, in the constructed canopy 3D structure, the light cutoff and nitrogen content are added as triangular surface element attribute parameters, and the instantaneous net photosynthetic rate of the leaves is calculated at the surface element scale, that is, the calculation accuracy of the canopy photosynthetic productivity is improved by surface element scale light and nitrogen fusion.

[0045] Step 140, according to the daily accumulation of the average instantaneous net photosynthetic rate and the PAR interception intensity in the population, obtain the daily light energy utilization efficiency of the canopy of the target plant for the screening of high light efficiency germplasm resources or varieties; wherein the daily accumulation of the PAR interception intensity in the population is determined based on the photosynthetically active radiation interception intensity of each leaf element, and the photosynthetically active radiation interception intensity is determined based on the daily radiation data of the target plant and the area of ​​each leaf element.

[0046] In this embodiment, after obtaining the average instantaneous net photosynthetic rate of the leaf element of the corn three-dimensional model, the canopy daily light energy utilization efficiency of the corn three-dimensional model is obtained by the following steps: (6) The net CO2 assimilation of each leaf element is obtained based on the leaf element area and the average instantaneous net photosynthetic rate.

[0047] In this embodiment, the above average instantaneous net photosynthetic rate A i,j,k,t Multiply by the corresponding blade surface area L i,j,k , and obtain the net CO2 assimilation of the surface element.

[0048] (7) Calculate the instantaneous photosynthetic rate of the three-dimensional model of a single plant based on the net CO2 assimilation of each leaf element, and then calculate the daily CO2 assimilation of the group based on the instantaneous photosynthetic rate corresponding to each three-dimensional model of the single plant.

[0049] In this embodiment, the first i Plants in t Instantaneous photosynthetic rate per plant per hour A plant,i,t (Unit, μmol plant -2 s -1 ): ; in, N i For the i The total number of facets of the strain, For the i The plantj The leaves are t The average instantaneous net photosynthetic rate per hour, For the i The plant j The area of ​​a leaf.

[0050] In this embodiment, the number of plants M (e.g., 9 plants) in the middle of the selected group is averaged and multiplied by the planting density D (unit: plants m -2 ), that is, the following formula is used to calculate the t Average instantaneous photosynthetic rate of corn canopy per unit land area per hour A can,t (Unit, μmol m -2 s -1 ): .

[0051] In this embodiment, the hourly canopy instantaneous photosynthetic rate calculated above is A can,t The cumulative sum can be used to obtain the daily CO2 assimilation of the group. A canDAY,d (Unit, μmol m -2 d -1 ), which is expressed by the following formula: .

[0052] (8) Calculate the daily dry matter accumulation of the target plant population based on the daily CO2 assimilation of the population.

[0053] In this embodiment, the daily CO2 assimilation of the group obtained above is A canDAY,d Multiply by the molar mass of CO2 (44, constant), then multiply by the CO2-dry matter conversion coefficient of corn C r (0.41, constant), the daily dry matter accumulation of the group can be obtained (unit, DM d , gm -2 d -1 ), which is specifically expressed by the following formula: .

[0054] (9) The daily light energy utilization efficiency of the canopy is determined based on the ratio of the daily dry matter accumulation of the colony to the daily accumulation of PAR interception intensity in the colony.

[0055] In this embodiment, the blade PAR interception intensity I i,j,t Converted into the daily accumulation of PAR interception intensity in the population IPAR DAY,d (MJ m -2 d -1 ), which is specifically expressed by the following formula: ; .

[0056] In this embodiment, the canopy daytime light energy utilization efficiency RUE DAY,d (Unit, g MJ -1 ) can be calculated according to the following formula: .

[0057] In this embodiment, the above step 130 uses a 3D canopy photosynthesis model to scale the instantaneous net photosynthetic rate and light interception of the leaves, obtain the daily dry matter and light interception accumulation of the corn canopy, and then obtain the daily RUE of the canopy through the ratio of the two, providing a basis for the accurate identification of the light energy utilization efficiency of corn at the variety level throughout the growth period.

[0058] The method for estimating the light energy utilization efficiency of plant canopies provided by the embodiment of the present invention constructs a group canopy geometric model through a multi-view RGB image sequence of a target plant, calculates the specific leaf nitrogen content SLN of each leaf element according to the spectral reflectance of the corresponding band of the leaf element for each plant single plant three-dimensional model, and calculates the net photosynthetic rate (A) of each leaf element under saturated light intensity according to the SLN. max ); the average instantaneous net photosynthetic rate of each leaf element is calculated based on the instantaneous photosynthetically active radiation (PAR) intensity intercepted by the leaf element; the daily light energy utilization efficiency of the canopy of the target plant is obtained based on the daily accumulation of the average instantaneous net photosynthetic rate and the PAR interception intensity in the population, so as to screen high-light-efficiency germplasm resources or varieties. The calculation accuracy of canopy photosynthetic productivity is improved by fusion of light and nitrogen at the element scale, and the accuracy and efficiency of estimating canopy light energy utilization efficiency at the field plot scale are improved.

[0059] In some embodiments, constructing a group canopy geometry model based on a multi-perspective RGB image sequence of a target plant includes: performing three-dimensional reconstruction on the multi-perspective RGB image sequence to obtain plant three-dimensional point cloud data, gridding the plant three-dimensional point cloud data, and constructing a group canopy geometry model based on the gridded point cloud data based on a method of a t-distributed corn group three-dimensional model; wherein multiple plant individual three-dimensional models in the group canopy geometry model are obtained by replicating a central target group around the reconstructed target group.

[0060] In this embodiment, a method for a three-dimensional model of a corn population based on t distribution is described: first, a t distribution function of the main plant type parameters is constructed through corn leaf parameters, and the main plant type parameters of each plant in the population are generated under this constraint; specifically, this is achieved through the following steps: (1) Constructing the t-distribution function: Using measured data, construct the t-distribution function of the main plant type parameters of the corn population (such as plant height, total number of leaves, first leaf index, etc.); (2) Generate plant type parameters: Under the constraints of the t distribution function, randomly generate the main plant type parameters of each plant in the population; (3) Generate a population geometry model: By constructing a plant type parameter similarity measurement function, the corresponding organ geometry template is called from the corn organ 3D template resource library, and then the two sets of population structure information, namely the growth position of each plant and the plant orientation plane angle extracted by manual interaction or image extraction, are combined to generate a corn population geometry model.

[0061] In this embodiment, in the process of generating the group geometric model, a Structure From Motion (SFM) method can be used to process the acquired multi-view RGB images, and the reconstructed three-dimensional point cloud of the corn plant can be gridded.

[0062] In this embodiment, in the process of constructing a three-dimensional model of a corn population canopy (e.g., 3 rows × 3 columns) using a method of a three-dimensional model of a corn population based on t-distribution, the leaf angle and azimuth of each plant are randomly selected within the normal distribution range.

[0063] In this embodiment, the central target group is replicated around the reconstructed target group to form a group canopy of 900 plants (30 rows×30 columns), which can avoid the calculation error of light distribution in the canopy caused by the edge row effect.

[0064] The method for estimating the light energy utilization efficiency of a plant canopy provided in an embodiment of the present invention grids multispectral point cloud data and constructs a population canopy geometric model based on the gridded point cloud data using a method of a three-dimensional model of a corn population based on t distribution. This can reduce the calculation error of the light distribution in the canopy caused by the edge row effect, improve the accuracy of the area of ​​the face element and the amount of photosynthetically active radiation intercepted, and thus improve the accuracy of the daily light energy utilization efficiency of the plant canopy.

[0065] Figure 2 This is the second flow chart of the method for estimating the light energy utilization efficiency of plant canopy provided by the present invention. Figure 2In the illustrated embodiment, a method for screening corn germplasm resources or varieties includes: (1) obtaining multispectral point cloud data of corn plants; (2) constructing a corn population geometric model based on a multi-view RGB image sequence; (3) parsing leaf surface element photosynthetic phenotypic parameters based on the corn population geometric model combined with the corn plant multispectral point cloud data; (4) calculating 3D canopy light energy utilization rate based on the leaf surface element photosynthetic phenotypic parameters; (5) obtaining the canopy light energy utilization efficiency of large-scale corn germplasm resources or varieties based on the 3D canopy light energy utilization rate; and (6) ultimately achieving the screening of corn germplasm resources or varieties.

[0066] The plant canopy light energy utilization efficiency estimation device provided by the present invention is described below. The plant canopy light energy utilization efficiency estimation device described below and the plant canopy light energy utilization efficiency estimation method described above can be referenced to each other.

[0067] Figure 3 Schematic diagram of the structure of the device for estimating the light energy utilization efficiency of plant canopy provided by the present invention. Figure 3 As shown, the plant canopy light energy utilization efficiency estimation device includes: a model building module 310, a first calculation module 320, a second calculation module 330 and a third calculation module 340.

[0068] A model building module 310 is used to build a group canopy geometry model according to a multi-view RGB image sequence of a target plant, wherein the group canopy geometry model includes a plurality of plant individual three-dimensional models, and each plant individual three-dimensional model includes a plurality of leaf facets; The first calculation module 320 is used to calculate the specific leaf nitrogen content SLN of each leaf element according to the spectral reflectance of the corresponding band of the leaf element for each plant three-dimensional model, and calculate the net photosynthetic rate of each leaf element under saturated light intensity according to the SLN; The second calculation module 330 is used to calculate the average instantaneous net photosynthetic rate of each leaf element according to the instantaneous photosynthetically active radiation PAR intensity and the net photosynthetic rate intercepted by the leaf element; The third calculation module is used to obtain the daily light energy utilization efficiency of the canopy of the target plant based on the daily cumulative amount of the average instantaneous net photosynthetic rate and the PAR interception intensity in the population, so as to screen high-light-efficiency germplasm resources or varieties; wherein the daily cumulative amount of the PAR interception intensity in the population is determined based on the photosynthetically active radiation interception intensity of each leaf surface element, and the photosynthetically active radiation interception intensity is determined based on the daily radiation data of the target plant and the area of ​​each leaf surface element.

[0069] The plant canopy light energy utilization efficiency estimation device provided by the embodiment of the present invention constructs a group canopy geometric model according to a multi-view RGB image sequence of a target plant, calculates the specific leaf nitrogen content SLN of each leaf element according to the spectral reflectance of the corresponding band of the leaf element for each plant single plant three-dimensional model, and calculates the net photosynthetic rate (A) of each leaf element under saturated light intensity according to the SLN. max ); the average instantaneous net photosynthetic rate of each leaf element is calculated based on the instantaneous photosynthetically active radiation (PAR) intensity intercepted by the leaf element; the daily light energy utilization efficiency of the canopy of the target plant is obtained based on the daily accumulation of the average instantaneous net photosynthetic rate and the PAR interception intensity in the population, so as to screen high-light-efficiency germplasm resources or varieties. The calculation accuracy of canopy photosynthetic productivity is improved by fusion of light and nitrogen at the element scale, and the accuracy and efficiency of estimating canopy light energy utilization efficiency at the field plot scale are improved.

[0070] Figure 4 is a schematic diagram of the structure of the electronic device provided by the present invention, such as Figure 4 As shown, the electronic device may include: a processor 410, a communication interface 420, a memory 430 and a communication bus 440, wherein the processor 410, the communication interface 420 and the memory 430 communicate with each other through the communication bus 440. The processor 410 may call the logic instructions in the memory 430 to execute a method for estimating the light energy utilization efficiency of a plant canopy, the method comprising: constructing a group canopy geometry model according to a multi-view RGB image sequence of a target plant, the group canopy geometry model comprising a plurality of plant individual three-dimensional models, each plant individual three-dimensional model comprising a plurality of leaf facets; for each plant individual three-dimensional model, calculating the specific leaf nitrogen content SLN of each leaf facet according to the spectral reflectance of the corresponding band of the leaf facet, and calculating the net photosynthetic rate of each leaf facet under saturated light intensity according to the SLN; The average instantaneous net photosynthetic rate of each leaf element is calculated based on the instantaneous photosynthetically active radiation PAR intensity and the net photosynthetic rate intercepted by the leaf element; the daily light energy utilization efficiency of the canopy of the target plant is obtained based on the daily accumulation of the average instantaneous net photosynthetic rate and the PAR interception intensity in the population, so as to screen high-light-efficiency germplasm resources or varieties; wherein the daily accumulation of the PAR interception intensity in the population is determined based on the photosynthetically active radiation interception intensity of each leaf element, and the photosynthetically active radiation interception intensity is determined based on the daily radiation data of the target plant and the area of ​​each leaf element.

[0071] In addition, the logic instructions in the above-mentioned memory 430 can be implemented in the form of a software functional unit and can be stored in a computer-readable storage medium when it is sold or used as an independent product. Based on this understanding, the technical solution of the present invention, in essence, or the part that contributes to the prior art or the part of the technical solution, can be embodied in the form of a software product, and the computer software product is stored in a storage medium, including a number of instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the method described in each embodiment of the present invention. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), disk or optical disk, etc. Various media that can store program codes.

[0072] On the other hand, the present invention also provides a computer program product, which includes a computer program. The computer program can be stored on a non-transitory computer-readable storage medium. When the computer program is executed by a processor, the computer can execute the plant canopy light energy utilization efficiency estimation method provided by the above methods. The method includes: constructing a group canopy geometry model based on a multi-view RGB image sequence of the target plant, the group canopy geometry model includes a plurality of plant individual three-dimensional models, and each plant individual three-dimensional model includes a plurality of leaf face elements; for each plant individual three-dimensional model, calculating the leaf ratio of each leaf face element according to the spectral reflectance of the corresponding band of the leaf face element The nitrogen content SLN is calculated, and the net photosynthetic rate of each leaf element under saturated light intensity is calculated according to the SLN; the average instantaneous net photosynthetic rate of each leaf element is calculated according to the instantaneous photosynthetically active radiation PAR intensity and the net photosynthetic rate intercepted by the leaf element; the daily light energy utilization efficiency of the canopy of the target plant is obtained according to the daily accumulation of the average instantaneous net photosynthetic rate and the PAR interception intensity in the population, so as to screen high light efficiency germplasm resources or varieties; wherein, the daily accumulation of the PAR interception intensity in the population is determined based on the photosynthetically active radiation interception intensity of each leaf element, and the photosynthetically active radiation interception intensity is determined based on the daily radiation data of the target plant and the area of ​​each leaf element.

[0073] On the other hand, the present invention also provides a non-transitory computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, is implemented to execute the plant canopy light energy utilization efficiency estimation method provided by the above-mentioned methods, the method comprising: constructing a group canopy geometry model according to a multi-view RGB image sequence of a target plant, the group canopy geometry model comprising a plurality of plant individual three-dimensional models, each plant individual three-dimensional model comprising a plurality of leaf face elements; for each plant individual three-dimensional model, calculating the specific leaf nitrogen content SLN of each leaf face element according to the spectral reflectance of the corresponding band of the leaf face element, and calculating the specific leaf nitrogen content SLN according to the SLN. Calculate the net photosynthetic rate of each leaf element under saturated light intensity; calculate the average instantaneous net photosynthetic rate of each leaf element according to the instantaneous photosynthetically active radiation PAR intensity and the net photosynthetic rate intercepted by the leaf element; obtain the daily light energy utilization efficiency of the canopy of the target plant according to the daily accumulation of the average instantaneous net photosynthetic rate and the PAR interception intensity in the population, so as to screen high light efficiency germplasm resources or varieties; wherein, the daily accumulation of the PAR interception intensity in the population is determined based on the photosynthetically active radiation interception intensity of each leaf element, and the photosynthetically active radiation interception intensity is determined based on the daily radiation data of the target plant and the area of ​​each leaf element.

[0074] The device embodiments described above are merely illustrative, wherein the units described as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units, that is, they may be located in one place, or they may be distributed on multiple network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the scheme of this embodiment. Ordinary technicians in this field can understand and implement it without paying creative labor.

[0075] Through the description of the above implementation methods, those skilled in the art can clearly understand that each implementation method can be implemented by means of software plus a necessary general hardware platform, and of course, can also be implemented by hardware. Based on this understanding, the above technical solution is essentially or the part that contributes to the prior art can be embodied in the form of a software product, and the computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, a disk, an optical disk, etc., including a number of instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to execute the methods described in each embodiment or some parts of the embodiments.

[0076] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for estimating plant canopy light energy utilization efficiency, characterized in that: include: Constructing a group canopy geometry model based on a multi-view RGB image sequence of a target plant, wherein the group canopy geometry model includes a plurality of plant individual three-dimensional models, and each plant individual three-dimensional model includes a plurality of leaf face elements; For each plant three-dimensional model, the specific leaf nitrogen content SLN of each leaf element is calculated according to the spectral reflectance of the corresponding band of the leaf element, and the net photosynthetic rate of each leaf element under saturated light intensity is calculated according to SLN; Calculating the average instantaneous net photosynthetic rate of each leaf element according to the instantaneous photosynthetically active radiation PAR intensity intercepted by the leaf element and the net photosynthetic rate; According to the daily accumulation of the average instantaneous net photosynthetic rate and the PAR interception intensity in the population, the daily light energy utilization efficiency of the canopy of the target plant is obtained for the screening of high-light-efficiency germplasm resources or varieties; wherein the daily accumulation of the PAR interception intensity in the population is determined based on the photosynthetically active radiation interception intensity of each leaf element, and the photosynthetically active radiation interception intensity is determined based on the daily radiation data of the target plant and the area of ​​each leaf element.

2. The method for estimating plant canopy light energy utilization efficiency according to claim 1, characterized in that: The method of calculating the specific leaf nitrogen content SLN of each leaf element according to the spectral reflectance of the corresponding band of the leaf element comprises: The hyperspectral vegetation index CCCI is calculated based on the spectral reflectance of each band of the leaf surface element; Linear regression calculation is performed based on CCCI to obtain the relative chlorophyll content SPAD of each leaf element, and the SLN is calculated based on the SPAD.

3. The method for estimating plant canopy light energy utilization efficiency according to claim 1, characterized in that: The method of calculating the average instantaneous net photosynthetic rate of each leaf element according to the instantaneous photosynthetically active radiation PAR intensity intercepted by the leaf element and the net photosynthetic rate comprises: Calculating light distribution according to the group canopy geometry model and the daily radiation data to obtain the area of ​​each leaf element and the interception amount of photosynthetically active radiation; Calculating the photosynthetically active radiation interception intensity of each leaf element according to the area of ​​the leaf element and the photosynthetically active radiation interception amount; The average instantaneous net photosynthetic rate is determined based on the light response curve model according to the net photosynthetic rate of each leaf element under saturated light intensity and the photosynthetically active radiation interception intensity.

4. The method for estimating plant canopy light energy utilization efficiency according to claim 1, characterized in that: The daily light energy utilization efficiency of the canopy of the target plant obtained according to the daily accumulation of the average instantaneous net photosynthetic rate and the PAR interception intensity in the population includes: Obtaining the net assimilation of CO2 of each leaf element according to the area of ​​the leaf element and the average instantaneous net photosynthetic rate; Calculate the instantaneous photosynthetic rate of the plant single plant three-dimensional model according to the net CO2 assimilation of each leaf element, and then calculate the daily CO2 assimilation of the group according to the instantaneous photosynthetic rate corresponding to each plant single plant three-dimensional model; Calculate the daily dry matter accumulation of the target plant population according to the daily CO2 assimilation of the population; The daily light energy utilization efficiency of the canopy is determined based on the ratio of the daily dry matter accumulation of the population to the daily PAR interception of the population.

5. The method for estimating plant canopy light energy utilization efficiency according to claim 1, characterized in that: The method of constructing a group canopy geometric model based on a multi-view RGB image sequence of a target plant comprises: Performing three-dimensional reconstruction on the multi-view RGB image sequence to obtain three-dimensional point cloud data of the plant; The plant three-dimensional point cloud data is gridded, and the group canopy geometry model is constructed based on the gridded point cloud data using a t-distributed corn group three-dimensional model method; wherein multiple plant individual three-dimensional models in the group canopy geometry model are obtained by replicating a central target group around the reconstructed target group.

6. The method for estimating plant canopy light energy utilization efficiency according to claim 1, characterized in that: The spectral reflectance of the blade surface element corresponding to the waveband is obtained by the following steps: Collecting a multi-view RGB image sequence and a multi-view multi-spectral image sequence of the target plant; Performing three-dimensional reconstruction on the multi-view RGB image sequence to obtain three-dimensional colored point cloud data; performing mapping processing on the multi-view multi-spectral image sequence to the multi-view RGB image to obtain multi-spectral colored point cloud data; The three-dimensional colored point cloud data and the multi-spectral colored point cloud data are fused to obtain the multi-spectral point cloud data, and the spectral reflectance is extracted from the multi-spectral point cloud data.

7. A device for estimating plant canopy light energy utilization efficiency, characterized in that: include: A model building module, used to build a group canopy geometry model according to a multi-view RGB image sequence of a target plant, wherein the group canopy geometry model includes a plurality of plant individual three-dimensional models, and each plant individual three-dimensional model includes a plurality of leaf facets; The first calculation module is used to calculate the specific leaf nitrogen content SLN of each leaf element according to the spectral reflectance of the corresponding band of the leaf element for each plant three-dimensional model, and calculate the net photosynthetic rate of each leaf element under saturated light intensity according to the SLN; The second calculation module is used to calculate the average instantaneous net photosynthetic rate of each leaf element according to the instantaneous photosynthetically active radiation PAR intensity intercepted by the leaf element and the net photosynthetic rate; The third calculation module is used to obtain the daily light energy utilization efficiency of the canopy of the target plant based on the daily cumulative amount of the average instantaneous net photosynthetic rate and the PAR interception intensity in the population, so as to screen high-light-efficiency germplasm resources or varieties; wherein the daily cumulative amount of the PAR interception intensity in the population is determined based on the photosynthetically active radiation interception intensity of each leaf surface element, and the photosynthetically active radiation interception intensity is determined based on the daily radiation data of the target plant and the area of ​​each leaf surface element.

8. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein: When the processor executes the computer program, the method for estimating plant canopy light energy utilization efficiency as described in any one of claims 1 to 6 is implemented.

9. A non-transitory computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the method for estimating plant canopy light energy utilization efficiency as claimed in any one of claims 1 to 6 is implemented.

10. A computer program product, comprising a computer program, characterized in that When the computer program is executed by a processor, the method for estimating plant canopy light energy utilization efficiency as claimed in any one of claims 1 to 6 is implemented.

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