Method for screening high-photosynthetic-efficiency crop filial generation based on photosynthetic parameters of normal distribution

Abstract

The invention relates to a high-photosynthetic-efficiency crop filial generation screening method based on normal-distribution photosynthetic parameters, and the method specifically comprises the following steps: determining the photosynthetic parameters on a large scale under a unified condition, analyzing and setting a screening threshold by combining normal-distribution characteristics, and rapidly screening out excellent filial generation with high-photosynthetic-efficiency characters. The method is scientific, efficient and suitable for breeding of grapes and other crops.

Description

[Technical field]

[0001] The invention relates to the technical field of crop breeding, and in particular to a method for screening high-photosynthetic-efficiency crop hybrid offspring based on normally distributed photosynthetic parameters. [Background technology]

[0002] In the process of crop breeding, high photosynthetic efficiency traits are important indicators that determine yield, quality and stress resistance. Traditional crop breeding methods rely on field trials and later phenotypic observations to screen excellent offspring. This method has a long cycle, low efficiency, and is easily affected by environmental interference. Photosynthetic parameters (such as net photosynthetic rate A and stomatal conductance gs) are core physiological indicators that reflect the photosynthetic capacity of crops. They are highly stable and reproducible, and can therefore be used for early screening of hybrid offspring. However, there is currently a lack of rapid and accurate methods for screening high-photosynthetic-efficiency hybrid offspring based on photosynthetic parameters.

[0003] The invention proposes a scientific and efficient screening method based on the normal distribution characteristics of photosynthetic parameters in hybrid offspring, which is used for screening high photosynthetic efficiency offspring in the early stage of breeding. [Summary of the invention]

[0004] In view of the above, it is necessary to provide a method for screening hybrid offspring of high-light-efficiency crops based on photosynthetic parameters of normal distribution. By large-scale determination of photosynthetic parameters under unified conditions and combining the analysis of normal distribution characteristics to set the screening threshold, excellent hybrid offspring with high-light-efficiency traits can be quickly screened out, which is suitable for the breeding of grapes and other crops.

[0005] In order to achieve the above object, the technical solution adopted by the present invention is:

[0006] A method for screening high-photosynthetic-efficiency crop hybrid offspring based on normal distribution of photosynthetic parameters, the method comprising the following steps:

[0007] (1) Determination of photosynthetic parameters: Under uniform environmental conditions, the photosynthetic parameters of crop hybrid offspring were measured, including net photosynthetic rate (A) and stomatal conductance (gs); and the water use efficiency (WUE) was calculated, where WUE = A / gs;

[0008] (2) Data statistical analysis: Calculate the mean (μ) and standard deviation (σ) of photosynthetic parameters of the hybrid offspring population and verify their normal distribution characteristics;

[0009] (3) Screening threshold setting: Based on the normal distribution characteristics, the screening threshold is set as:

[0010] a. Net photosynthetic rate (A) screening threshold: A = μ A +k A ·σ A ;

[0011] b. Stomatal conductance (gs) screening threshold: gs = μ gs +k gs ·σ gs ;

[0012] Among them, k A and k gs is an adjustment factor used to control the stringency of the screening criteria;

[0013] (4) Screening: According to the setting of step (3), the hybrid offspring that simultaneously meets the following conditions (conditions ac) are screened, that is, the hybrid offspring individuals of the high light-efficiency crop;

[0014] Among them, condition a: net photosynthetic rate A>max(μ A +k A ·σ A ,max(A 母本 ,A 父本 ));

[0015] Condition b: Stomatal conductance gs>μ gs +k gs ·σ gs ;

[0016] Condition c: Water use efficiency WUE>μ WUE .

[0017] Furthermore, the period for measuring the photosynthetic parameters in step (1) is when the leaves of the parents and the hybrid offspring are 30-50 days old.

[0018] Furthermore, the conditions for determining the photosynthetic parameters in step (1) are: the light intensity is 1500 μmol·m -2 ·s - 1. Temperature is 28℃, CO 2 The concentration is 400ppm.

[0019] Furthermore, the method also includes the construction of hybrid offspring, specifically selecting suitable parents and hybrid breeding to obtain an offspring group with a rich genetic background.

[0020] Furthermore, the crop is specifically grapes.

[0021] Furthermore, the step (3) adjusts the factor k A The value range is: 0.3≤k A ≤1.5, the value is flexibly adjusted according to the crop population data distribution, breeding objectives and the strictness of net photosynthetic rate screening.

[0022] Furthermore, the step (3) adjusts the factor k gs The value range is: -0.5≤k gs≤1, the value is flexibly adjusted according to the crop population data distribution, breeding objectives and the strictness of stomatal conductance screening.

[0023] The present invention has at least the following beneficial effects:

[0024] The present invention provides a method for screening high-photosynthetic-efficiency crop hybrid offspring based on normal distribution of photosynthetic parameters. Through large-scale photosynthetic parameter determination under unified conditions, combined with normal distribution characteristic analysis to set a screening threshold, excellent hybrid offspring with high-photosynthetic-efficiency traits can be quickly screened out. The method is scientific, efficient, and accurate, and is suitable for the breeding of grapes and other crops. Unlike traditional field experiments that rely on long time periods and are easily affected by the environment, this method is based on the normal distribution characteristics of photosynthetic parameters, and can quickly screen high-photosynthetic-efficiency excellent offspring in the early stages of breeding, reducing time costs and management costs, and improving screening efficiency.

Brief Description of the Drawings

[0025] Figure 1 are the photosynthetic parameter values ​​of the parent and its five hybrid offspring superior strains;

[0026] Figure 2 It is the soluble solid content of the parent and its five hybrid offspring superior strains;

[0027] In the figure, different lowercase letters above the columns indicate that the photosynthetic parameters are significantly different at the P < 0.05 level. [Specific implementation method]

[0028] In order to make the above-mentioned purpose, features and advantages of the present invention more obvious and easy to understand, the specific implementation of the present invention is described in detail below. In the following description, many specific details are set forth to facilitate a full understanding of the present invention. However, the present invention can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without violating the connotation of the present invention, so the present invention is not limited by the specific implementation disclosed below.

[0029] Example:

[0030] This embodiment is a method for screening high-photosynthetic-efficiency crop hybrid offspring based on normal distribution of photosynthetic parameters. In this embodiment, the specific crop is grapes, and the implementation steps include:

[0031] 1. Test materials

[0032] Hybrid combination: Sunshine Rose (female parent) × Ruidu Ruby (male parent).

[0033] Hybrid population: 158 hybrid lines.

[0034] Measurement conditions: light (1500 μmol·m -2 ·s -1), temperature 28℃, CO 2 Concentration 400ppm.

[0035] Measurement instrument: LI-6800F photosynthesis-fluorescence meter (LI-COR, USA).

[0036] 2. Filter results

[0037] A total of 22 high-light-efficiency hybrid offspring were screened out in this screening.

[0038] 3. Screening specific process

[0039] (1) Data Collection

[0040] Under uniform measurement conditions, the net photosynthetic rate (A) and stomatal conductance (gs) of the hybrid offspring population and parents were measured during the leaf age of 30-50 days.

[0041] (2) Statistical analysis

[0042] Verify that the net photosynthetic rate (A) and stomatal conductance (gs) of the hybrid offspring population are normally distributed, and calculate the mean (μ) and standard deviation (σ) of the photosynthetic parameters of the hybrid offspring population:

[0043] Net photosynthetic rate A: mean μ A =21.61 μmol·m -2 ·s -1 , standard deviation σ A =2.79 μmol·m -2 ·s -1 ;

[0044] Stomatal conductance gs: mean μ gs =0.557mol·m -2 ·s -1 , standard deviation σ gs =0.098mol·m -2 ·s -1 ;

[0045] Water use efficiency WUE: mean μ WUE =39.51 μmol·m -2 ·s -1 / mol·m -2 ·s -1 .

[0046] (3) Screening threshold setting

[0047] According to the distribution of population data, as well as the breeding goal of focusing on high light efficiency and ensuring moderate opening of stomatal conductance while taking into account water use efficiency, the strategy of strict screening for A and relaxing the screening criteria for gs was implemented, and the k value was adjusted to: k A=0.8, k gs =-0.5, the screening thresholds are as follows:

[0048] a. Net photosynthetic rate (A) screening threshold: A = μ A +k A ·σ A =23.84 μmol·m -2 ·s -1 ;

[0049] b. Stomatal conductance (g s ) Screening threshold: g s =μ gs +k gs ·σ gs =0.508mol·m -2 ·s -1 .

[0050] (4) Data screening

[0051] The hybrid offspring that simultaneously meets the following conditions are selected as the hybrid offspring individuals of high light-efficiency crops.

[0052] Condition a.: Net photosynthetic rate A>23.84 μmol·m -2 ·s -1 ;

[0053] Condition b: Stomatal conductance gs>0.508mol·m -2 ·s -1 ;

[0054] Condition c: Water use efficiency WUE>39.51 μmol·m -2 ·s -1 / mol·m -2 ·s -1 .

[0055] (5) Filter results

[0056] Finally, 22 hybrid offspring that met the screening criteria were screened out.

[0057] The representative high light-efficiency hybrid offspring individuals screened out are shown in Table 1:

[0058] Table 1 Photosynthetic parameters of parents and representative high-light-efficiency hybrid offspring selected

[0059]

[0060] 3. Field verification

[0061] Methods: The selected candidate offspring were transplanted to the field for growth. After the hybrid offspring bore fruit, the photosynthetic parameters of the leaves at 35 leaf age (net photosynthetic rate (A), stomatal conductance (gs), actual photochemical quantum efficiency of photosynthetic system II (ΦPSⅡ), electron transfer rate (ETR), etc.) were uniformly measured. After the fruits were ripe, the soluble solids content was measured to verify the high photosynthetic efficiency trait in the natural environment of the hot zone.

[0062] The photosynthetic efficiency and soluble solid content of the above-mentioned parents and five high-light-efficiency excellent strains are shown in Table 2:

[0063] Table 2 Photosynthetic efficiency and soluble solids of the parents and five high-efficiency strains

[0064]

[0065] The photosynthetic parameter values ​​of the superior strains of the parent and its five hybrid offspring are as follows: Figure 1 As shown in Figure 2, the soluble solid content values ​​of the parent and its five hybrid offspring are as follows: Figure 2 As shown in the figure, different lowercase letters above the columns indicate that the photosynthetic parameters are significantly different at the P < 0.05 level.

[0066] Results: Combined with the above data results, it was shown that the selected candidate offspring all exhibited significant high photosynthetic efficiency traits under the natural environment of the hot zone, and were significantly better than their parents in terms of net photosynthetic rate (A), actual photochemical quantum efficiency (ΦPSⅡ), electron transfer rate (ETR) and other indicators, and had excellent quality, further verifying the feasibility and effectiveness of the screening method described in this application.

[0067] The above examples only express several embodiments of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the present invention. It should be pointed out that, for those of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the attached claims.

Claims

1. A method for screening high-photosynthetic-efficiency crop hybrid offspring based on normal distribution of photosynthetic parameters, characterized in that: The method comprises the following steps: (1) Determination of photosynthetic parameters: Under uniform environmental conditions, the photosynthetic parameters of crop hybrid offspring were measured, including net photosynthetic rate A and stomatal conductance gs, and water use efficiency WUE was calculated, where WUE = A / gs; (2) Data statistical analysis: Calculate the mean μ and standard deviation σ of the photosynthetic parameters of the hybrid offspring population and verify their normal distribution characteristics; (3) Screening threshold setting: Based on the normal distribution characteristics, the screening threshold is set as: a. Net photosynthetic rate (A) screening threshold: A = μ A +k A ·σ A ; b. Stomatal conductance (gs) screening threshold: gs = μ gs +k gs ·σ gs ; Among them, k A and k gs is an adjustment factor used to control the stringency of the screening criteria; (4) Screening: According to the setting of step (3), screening hybrid offspring that simultaneously meet the following conditions, i.e., hybrid offspring individuals of high light-efficiency crops; Among them, condition a: net photosynthetic rate A>max(μ A +k A ·σ A ,max(A 母本 ,A 父本 )); Condition b: Stomatal conductance gs>μ gs +k gs ·σ gs ; Condition c: Water use efficiency WUE>μ WUE .

2. The method according to claim 1, characterized in that The period for measuring the photosynthetic parameters in step (1) is when the leaves of the parents and the hybrid offspring are 30-50 days old.

3. The method according to claim 1, characterized in that The conditions for determining the photosynthetic parameters in step (1) are: the light intensity is 1500 μmol·m -2 ·s - 1. The temperature is 28°C and the concentration of CO2 is 400ppm.

4. The method according to claim 1, characterized in that: The method also includes the construction of hybrid offspring, specifically selecting suitable parents and cross-breeding to obtain an offspring group with a rich genetic background.

5. The method according to claim 1, characterized in that: The crop is grapes.

6. The method according to claim 1, characterized in that The step (3) adjusts the factor k A The value range is: 0.3≤k A ≤1.

5.

7. The method according to claim 1, characterized in that The step (3) adjusts the factor k gs The value range is: -0.5≤k gs ≤1.

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