A rapid early screening method for high photosynthetic efficiency sugarcane varieties based on photosynthetic capacity

Abstract

The present invention discloses a method for early rapid screening of high photosynthetic efficiency sugarcane varieties based on photosynthetic capacity. The method uses sugarcane varieties in regional trials or variety comparison areas as materials, waits for the sugarcane varieties to grow to the early stage of jointing (9 to 11 true leaves), and rapidly and non-destructively measures the photosynthetic electron flow of functional leaves (the first fully expanded leaf at the top) under different light intensities to calculate the photosynthetic potential of a single leaf; then combines the leaf area index with the distribution of photosynthetically active radiation intensities over many years to obtain the photosynthetic capacity of different sugarcane varieties; selects 10 sugarcane varieties, establishes a correlation between their photosynthetic capacity and the theoretical yield and sugar brix obtained based on field surveys at harvest time to calculate the sugar production capacity of different sugarcane varieties, and calculates the fitting degree of the regression model to the data. R 2 =0.856; another 23 sugarcane varieties were used for verification. The results showed that the determination coefficient based on the 1:1 line ( r 2 ) and the relative regression estimate standard error ( rRMSE ) were 0.849 and 2.78% respectively, indicating that this method can be well used for the evaluation and screening of high light-efficiency sugarcane varieties.

Description

Technical Field

[0001] The invention relates to the technical field related to sugarcane breeding, and in particular to an early rapid screening method for high-light-efficiency sugarcane varieties based on photosynthetic capacity. Background Art

[0002] Sugarcane is an important sugar crop, accounting for 90% of the source of sugar. High photosynthetic efficiency is the basis for the formation of two key economic traits of sugarcane, high yield and high sugar content. Taking into account the distribution background of photosynthetically active radiation in sugarcane producing areas for many years, the photosynthetic capacity is calculated by photosynthetic efficiency and photosynthetic area, and a regression model is established with the sugar production capacity estimated at the harvest time. Then, the photosynthetic capacity is used to invert the sugar production capacity of different sugarcane varieties in the early and middle stages of sugarcane growth, so as to achieve early and rapid screening of high-photosynthetic efficiency sugarcane varieties. Compared with traditional yield measurement and chemical analysis at the harvest time, it can shorten the time of screening high-quality and high-yield sugarcane varieties from a large number of hybrid seedlings, greatly reduce breeding costs, and is of great significance for the selection and breeding of new high-yield and high-sugar sugarcane varieties. Summary of the invention

[0003] The object of the present invention is to provide a method for early rapid screening of high-light-efficiency sugarcane varieties based on photosynthetic capacity. The method calculates the photosynthetic capacity and inverts its sugar production capacity by rapid and non-destructive detection of the photosynthetic efficiency and photosynthetic area of ​​different sugarcane varieties in the early and middle stages of sugarcane growth, thereby achieving early rapid screening and evaluation of new high-light-efficiency sugarcane varieties.

[0004] To achieve the above object, the present invention provides the following technical solution: a method for early rapid screening of high photosynthetic efficiency sugarcane varieties based on photosynthetic capacity, comprising the following steps:

[0005] (1) Calculation of single leaf photosynthetic potential: A chlorophyll fluorescence instrument was used to measure the photosynthetic electron flow (E) of the functional leaves (the first fully expanded leaf at the top) in the early stage of jointing of the test sugarcane (9-11 true leaves) under different light intensities. J ) and draw the light response curve, and obtain the light response curves in different photosynthetically active radiation ranges according to the fitting curve. J The integrated area of ​​​​the photosynthetic potential of a single leaf under different light intensities J P .

[0006] (2) Determination of photosynthetically active radiation distribution: Using the minute data set obtained by the farmland microclimate monitoring system, we calculated the distribution of photosynthetically active radiation in different light intensity ranges over the past five years. PAR The proportion of PPTY ).

[0007] (3) Determination of photosynthetic area: measuring the leaf length of functional leaves of different sugarcane varieties ( L ) and leaf width ( W), and use a handheld laser leaf area meter to measure the leaf area, and calculate the empirical coefficient (θ) for converting leaf length and width to leaf area; select an average single plant in the field for each variety, measure the length and width of the leaves that can provide photosynthetic area leaf by leaf, and calculate the total leaf area based on θ; then calculate the total leaf area based on the planting density ( ρ ) and the number of effective tillers per unit area from field statistics ( N ) to calculate the leaf area index ( LAI ).

[0008] (4) Calculation of photosynthetic capacity: The products of single leaf photosynthetic potential and the proportion of photosynthetically active radiation in different light intensity ranges were added together and then multiplied by the leaf area index to obtain the photosynthetic capacity of different sugarcane varieties.

[0009] (5) Estimation of sugar production capacity: During the harvest period, the weight of a single stem of three rows of sugarcane (10 consecutive plants in each row) was investigated. SSW )、Field sugar brix( Brix ) and effective stem number ( ES ), using the average Brix to estimate the sucrose content ( SC ), using the average single stem weight and effective stem number to calculate the theoretical yield ( Yield ), and then calculate the sugar production capacity of different sugarcane varieties through theoretical yield and sucrose content ( SPC ).

[0010] (6) Use a linear equation to describe the relationship between photosynthetic capacity and sugar production capacity of different sugarcane varieties, and calculate the degree of fit of the regression model to the data R 2 ; Different sugarcane varieties were selected for verification, and the sugar production capacity estimated by photosynthetic capacity and the sugar production capacity calculated by harvest period were determined based on the 1:1 line ( r 2 ) and the relative regression estimate standard error ( rRMSE ) to evaluate the accuracy of this method.

[0011] As a preferred method, the photosynthetic potential of a single leaf ( J P ) During the calculation process, the photosynthetic electron flow is measured at the leaf position of 1 / 4 to 1 / 2 from the tip of the leaf. The calculation method is: (1).

[0012] As a preference, the PAR distribution range is divided into 50-500, 500-1000, 1000-1500, 1500-2000, 2000-2500 μmol·m -2 ·s -1 Five intervals (a is the lower limit of the interval, b is the upper limit of the interval). Within different light intensity ranges PAR The proportion of PPTY ) is calculated as: (2).

[0013] As a preferred method, 10 functional leaves of individual plants were selected to calculate the length, width and leaf area of ​​the leaves, and 3 plants with average growth potential were selected to calculate the total leaf area. The effective tillering statistical row length was 5m, and 4 rows were selected for each variety as replicates. Leaf area index ( LAI ) is calculated as: (3).

[0014] Preferably, 50 to 500, 500 to 1000, 1000 to 1500, 1500 to 2000, 2000 to 2500 μmol·m -2 ·s -1 The photosynthetic capacity of different sugarcane varieties was obtained by multiplying and summing the photosynthetic potential of a single leaf, the proportion of photosynthetically active radiation and the photosynthetic area within the light intensity range. PC ). The calculation method is: (4).

[0015] Preferably, the average Brix is ​​used to estimate the sucrose content ( SC ), using the average single stem weight and effective stem number to calculate the theoretical yield ( Yield ), and then calculate the sugar production capacity of different sugarcane varieties through theoretical yield and sucrose content ( SPC ). The calculation method is: (5).

[0016] As a preferred method, 10 sugarcane varieties were selected, and the relationship between photosynthetic capacity and sugar production capacity was described by a linear equation, and the degree of fit of the regression model to the data was calculated. R 2 =0.856, (6).

[0017] As a preferred method, 23 varieties were selected for verification. The results showed that the determination coefficient of the sugar production capacity estimated by the photosynthetic capacity at the early jointing stage and the sugar production capacity measured at the harvest stage based on the 1:1 line was ( r 2 ) and the relative regression estimate standard error ( rRMSE ) were 0.849 and 2.78% respectively.

[0018] Compared with the prior art, the present invention has the following beneficial effects:

[0019] (1) Compared with the light response curve drawn by measuring the CO2 assimilation rate (material metabolism) using a photosynthesis meter, the light response curve drawn by measuring the photosynthetic electron flow using a portable chlorophyll fluorescence meter starts from photosynthetic energy metabolism, has a rapid response, and does not require time-consuming instrument leveling. This is conducive to the rapid measurement of more sugarcane plants during the screening of high-light-efficiency sugarcane varieties.

[0020] (2) According to PAR Range: 50-500, 500-1000, 1000-1500, 1500-2000, 2000-2500 μmol·m -2 ·s -1 There are two reasons for dividing the interval into standards: first, crops need a certain PAR under weak light to meet the energy required to maintain the operation of the light system, so PAR < 50 can be ignored for photosynthetic carbon assimilation; for the outdoor sunny day, the illuminance is greater than 30,000 lux, which is converted to PAR About 540 μmol·m -2 ·s -1 ; For crops, the light saturation point for sugarcane is between 80,000 and 100,000 lux, which is converted to PAR About 1500~1800 μmol·m -2 ·s -1 Taking all factors into consideration, we used a PAR interval of 500 μmol·m -2 ·s -1 is an interval, and the five intervals represent the response of sugarcane to low light, medium light, high light, saturated light, and light inhibition. Second, as the longitude, latitude and altitude change in different regions, the proportion of PAR in each interval varies greatly, and different sugarcane varieties have different light adaptability (some varieties adapt to medium light, some varieties tolerate weak light or strong light), resulting in a large difference in the area of ​​their light response curves falling in different PAR ranges. Only by combining with the environmental background of the experimental area can the environmental adaptability of different sugarcane varieties be truly reflected.

[0021] (3) Sugarcane is a large herbaceous crop. Calculating the total leaf area based on the leaf coefficient of the functional leaf and the leaf length and width can more accurately reflect the actual photosynthetic area, especially for the lower aging and yellowing leaves and the upper leaves that have not fully expanded. The photosynthetic area can only be accurately grasped during the leaf-by-leaf measurement process.

[0022] (4) The reason for measuring various indicators at the early stage of sugarcane jointing is that although the photosynthetic efficiency can be compared at the seedling stage, the effective tillering directly determines the size of the light and area of ​​sugarcane and is a key trait for the formation of sugarcane yield. The jointing stage is the period when photosynthesis is most active. The photosynthetic potential calculated at this time can more effectively reflect the photosynthetic characteristics of sugarcane varieties.

[0023] (5) The theoretical yield calculated by single stem weight and effective stem number and the sucrose content estimated by average field sugar hammer can more accurately reflect the sugar production capacity of sugarcane. Therefore, a correlation between photosynthetic capacity and sugar production capacity is established. The prediction of sugar production capacity by photosynthetic capacity has a corresponding theoretical basis and can also greatly reduce the time required to screen high photosynthetic efficiency sugarcane varieties. Implementation

[0024] The technical solutions in the present invention are fully and clearly described in conjunction with examples. The examples do not represent all examples of the present invention. All other embodiments obtained by those skilled in the art based on the contents in the examples of the present invention without making any creative work shall fall within the scope of protection of the present invention.

[0025] The present invention provides a technical solution: a method for early rapid screening of high-light-efficiency sugarcane varieties based on photosynthetic capacity, the specific operation is as follows:

[0026] (1) Calculation of single leaf photosynthetic potential: A chlorophyll fluorescence meter was used to measure the photosynthetic electron flow (E) of the functional leaf (the first fully expanded leaf on the top) at different light intensities from the tip of the leaf at 1 / 4 to 1 / 2 of the leaf position at the early stage of jointing (9 to 11 true leaves) of the test sugarcane. J ) and draw the light response curve, and obtain the light response curves in different photosynthetically active radiation ranges according to the fitting curve. J The integrated area of ​​​​the photosynthetic potential of a single leaf under different light intensities J P . (1).

[0027] Among them, [a, b] is divided into five intervals, namely 50-500, 500-1000, 1000-1500, 1500-2000, and 2000-2500 μmol·m -2 ·s -1 .

[0028] (2) Determination of photosynthetically active radiation distribution: Using the minute data set obtained by the farmland microclimate monitoring system, the distribution of photosynthetically active radiation in the past five years ( y ) 50-500, 500-1000, 1000-1500, 1500-2000, 2000-2500 μmol·m -2 ·s -1 Light intensity range PAR The proportion of PPTY ). (2).

[0029] (3) Determination of photosynthetic area: 10 plants of each variety were selected to measure the leaf length of functional leaves of different sugarcane varieties ( L ) and leaf width ( W ), and use a handheld laser leaf area meter to measure leaf area, and calculate the empirical coefficient (θ) for converting leaf length and width to leaf area; select an average of 3 individual plants in the field for each variety, measure the length and width of the leaves that can provide photosynthetic area leaf by leaf, and calculate the total leaf area based on θ; count the number of effective tillers of 10m long sugarcane rows, and calculate the number of effective tillers per unit area ( N ), and then according to the planting density ( ρ) and calculation of leaf area index ( LAI ), 4 rows were counted for each variety as replicates. (3).

[0030] Among them, n is the number of selected plants for each variety, and m is the number of repeated rows.

[0031] (4) Calculation of photosynthetic capacity: 50-500, 500-1000, 1000-1500, 1500-2000, 2000-2500 μmol·m -2 ·s -1 The photosynthetic capacity of different sugarcane varieties was obtained by multiplying and summing the photosynthetic potential of a single leaf, the proportion of photosynthetically active radiation and the photosynthetic area within the light intensity range. PC ). (4).

[0032] (5) Estimation of sugar production capacity: During the harvest period, the weight of a single stem of three rows of sugarcane (10 consecutive plants in each row) was investigated. SSW )、Field sugar brix( Brix ) and effective stem number ( ES ), using the average Brix to estimate the sucrose content ( SC ), using the average single stem weight and effective stem number to calculate the theoretical yield ( Yield ), and then calculate the sugar production capacity of different sugarcane varieties through theoretical yield and sucrose content ( SPC ). (5).

[0033] (6) A linear equation was used to describe the relationship between photosynthetic capacity and sugar production capacity of 10 sugarcane varieties (see Figure 1 ), calculate the degree of fit of the regression model to the data R 2 =0.856; (6).

[0034] Another 23 varieties were used for verification, and the results showed that the determination coefficient of the sugar production capacity estimated by the photosynthetic capacity at the early jointing stage and the sugar production capacity measured at the harvest stage based on the 1:1 line ( r 2 ) and the relative regression estimate standard error ( rRMSE ) were 0.849 and 2.78% respectively (see Figure 2 ).

[0035] This shows that this method can be well used for the evaluation and screening of high light-efficiency sugarcane varieties.

[0036] Description of the drawings.

[0037] Figure 1. Relationship between photosynthetic capacity and sugar production capacity of different sugarcane varieties.

[0038] Figure 2 . The sugar production capacity of the model-independent varieties estimated based on the photosynthetic capacity at the early jointing stage and the sugar production capacity calculated based on the actual measurements at the harvest stage were verified based on a 1:1 line.

[0039] In addition, in the examples of the present application, each functional module can be freely integrated or exist independently.

[0040] If the function is implemented in the form of a software function module and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present application is essentially 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, which is stored in a storage medium and includes several instructions to enable 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 application. 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. It should be noted that in this article, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations.

[0041] The above description is only the preferred embodiment of the present application and is not intended to limit the present application. For those skilled in the art, the present application may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

[0042] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any person skilled in the art who is familiar with the present technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims

1. A method for rapid early screening of high-efficiency sugarcane varieties based on photosynthetic capacity, the main steps of which include: (1) Calculation of single leaf photosynthetic potential: A chlorophyll fluorescence instrument was used to measure the photosynthetic electron flow of the functional leaves of the test sugarcane with 9 to 11 true leaves at the early stage of jointing at 6:00 am to 12:00 pm. The photosynthetic electron flow of the upper leaf of the first fully expanded leaf under different light intensities was selected. J And draw the light response curve, and calculate the light response curve in different photosynthetically active radiation ranges according to the fitting curve. J The integrated area of ​​​​the photosynthetic potential of a single leaf under different light intensities J P ; (2) Determination of photosynthetically active radiation distribution: Using the minute data set obtained by the farmland microclimate monitoring system, the different light intensity ranges in the past five years were calculated. PAR The proportion of PPTY ; (3) Determination of photosynthetic area: measuring the leaf length of functional leaves of different sugarcane varieties L Kazuha Hiro W The leaf area was measured with a handheld laser leaf area meter, and the empirical coefficient θ for converting leaf length and width to leaf area was calculated. For each variety, the average single plant in the field was selected, and the length and width of the leaves that could provide photosynthetic area were measured leaf by leaf, and the total leaf area was calculated based on θ. Then, according to the planting density, the leaf area was calculated based on the leaf length and width. ρ and the number of effective tillers per unit area from field statistics N Calculate leaf area index LAI ; (4) Calculation of photosynthetic capacity: The products of single leaf photosynthetic potential and photosynthetically active radiation ratio in different light intensity ranges were added together and then multiplied by the leaf area index to obtain the photosynthetic capacity of different sugarcane varieties. (5) Estimation of sugar production capacity: During the harvest period, three rows of sugarcane were surveyed, with 10 plants in each row. The weight of a single stem was investigated. SSW , Field sugar brix Brix and effective stem number ES , using the average Brix to estimate sucrose content SC , using the average single stem weight and effective stem number to calculate the theoretical yield Yield , and then calculate the sugar production capacity of different sugarcane varieties through theoretical yield and sucrose content SPC ; (6) Use a linear equation to describe the relationship between photosynthetic capacity and sugar production capacity of different sugarcane varieties, and calculate the degree of fit of the regression model to the data R 2 Different sugarcane varieties were selected for verification, and the sugar production capacity estimated by photosynthetic capacity and the sugar production capacity calculated by harvest period were based on the determination coefficient of 1:1 line r 2 and the relative regression estimate standard error rRMSE Evaluate the accuracy of this method.

2. The method for early rapid screening of high photosynthetic efficiency sugarcane varieties based on photosynthetic capacity according to claim 1, characterized in that: The photosynthetic electron flow measurement time is the early stage of sugarcane jointing, that is, the stage of 9 to 11 true leaves, and the leaf position selected for measurement is the functional leaf, that is, the first fully expanded leaf on the upper part, which is 1 / 4 to 1 / 2 of the leaf position from the leaf tip; and PAR - J The curve fitting calculation is different PAR Light intensity range within the interval J The integrated area of ​​​​the photosynthetic potential of a single leaf under different light intensities J P , the calculation method is: (1) Among them, [a, b] is divided into five intervals, namely 50-500, 500-1000, 1000-1500, 1500-2000, and 2000-2500 μmol·m -2 ·s -1 .

3. The method for early rapid screening of high photosynthetic efficiency sugarcane varieties based on photosynthetic capacity according to claim 1, characterized in that: Using the minute data set obtained by the farmland microclimate monitoring system, the y 50-500, 500-1000, 1000-1500, 1500-2000, 2000-2500 μmol·m -2 ·s -1 Light intensity range PAR The proportion of PPTY: (2)。 4. The method for early rapid screening of high photosynthetic efficiency sugarcane varieties based on photosynthetic capacity according to claim 1, characterized in that: In the calculation of θ, ≥5 individual plants of each sugarcane variety were selected, ≥3 individual plants of each sugarcane variety were selected in the calculation of total leaf area, the effective tillering statistical row length was ≥3m, and the number of repeated rows of each variety was ≥3. Then, according to the effective tillering number per unit area, N and planting density ρ Calculate leaf area index LAI: (3) Among them, n is the number of selected plants for each variety, and m is the number of repeated rows.

5. The method for early rapid screening of high photosynthetic efficiency sugarcane varieties based on photosynthetic capacity according to claim 1, characterized in that: 50-500, 500-1000, 1000-1500, 1500-2000, 2000-2500 μmol·m -2 ·s -1 The photosynthetic capacity of different sugarcane varieties was obtained by multiplying and summing the photosynthetic potential of a single leaf, the proportion of photosynthetically active radiation and the photosynthetic area within the light intensity range. PC: (4)。 6. The method for early rapid screening of high photosynthetic efficiency sugarcane varieties based on photosynthetic capacity according to claim 1, characterized in that: During the harvest period, three rows of sugarcane were surveyed, with 10 plants in each row, and the weight of a single stem was investigated. SSW , Field sugar brix Brix and effective stem number ES , using the average Brix to estimate sucrose content SC , using the average single stem weight and effective stem number to calculate the theoretical yield Yield , and then calculate the sugar production capacity of different sugarcane varieties through theoretical yield and sucrose content SPC: (5)。 7. The method for early rapid screening of high photosynthetic efficiency sugarcane varieties based on photosynthetic capacity according to claim 1, characterized in that: There shall be no less than 5 representative sugarcane varieties used for establishing the empirical model, and no less than 10 independent sugarcane varieties used for model verification.

8. The method for early rapid screening of high photosynthetic efficiency sugarcane varieties based on photosynthetic capacity according to claim 1, characterized in that: A linear equation was used to describe the relationship between photosynthetic capacity and sugar production capacity of 10 sugarcane varieties, and the degree of fit of the regression model to the data was calculated. R 2 =0.856; (6) The results of the validation of 23 other varieties showed that the determination coefficient of the sugar production capacity estimated by the photosynthetic capacity at the early jointing stage and the sugar production capacity measured at the harvest stage was based on the 1:1 line. r 2 and the relative regression estimate standard error rRMSE They are 0.849 and 2.78% respectively.

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