Comprehensive identification model and method for wheat yield and nitrogen absorption efficiency, and application

Abstract

A comprehensive identification model and method for wheat yield and nitrogen absorption efficiency, and application, which relate to the technical field of agricultural planting. The method comprises the following steps: (1) population dynamics and yield measurement; (2) grain filling characteristic measurement; (3) grain filling parameter calculation; and (4) result analysis.

Description

A wheat yield and nitrogen absorption efficiency comprehensive identification model, method and application TECHNICAL FIELD

[0001] The present application relates to the field of agricultural planting technology, more particularly to a wheat yield and nitrogen absorption efficiency comprehensive identification model, method and application. BACKGROUND

[0002] Wheat is one of the important food crops, and the development of wheat industry is directly related to China's food security and social stability. In recent years, China's wheat production has increased year by year, but the increase is accompanied by excessive application of nitrogen fertilizer and decline in fertilizer efficiency, thereby affecting the healthy development of the ecological environment. How to reduce the nitrogen fertilizer consumption and improve the nitrogen absorption efficiency while maintaining high yield has become a hot research topic. Screening or breeding of nitrogen-efficient wheat varieties is the key to achieving high yield and efficiency and reducing environmental pollution. The grain filling process is an important physiological process that affects yield formation and nitrogen utilization efficiency. Clarifying the relationship between grain filling characteristics and wheat yield and nitrogen absorption efficiency can help promote the coordinated improvement of wheat yield and nitrogen utilization efficiency. Many studies have shown that there are differences in nitrogen efficiency among different crops or different varieties of the same crop, which in turn affect the differences in grain filling characteristics. Lv Jingyao et al. considered that different genotypes of maize have different nitrogen efficiencies, and the size of their nitrogen efficiency is different due to the different nitrogen demands of their respective genetic properties, which affects the development of maize kernels. Yang Jianchang et al. clarified that there are significant differences in grain filling characteristics among different types and varieties of rice. Li Min et al. analyzed the grain filling characteristics of strong and weak grains of different nitrogen-efficient indica rice varieties and their relationship with yield and nitrogen utilization, and proposed that an important way to promote the coordinated improvement of high yield and nitrogen efficiency of indica rice is to promote the filling of weak grains. Previous studies on crop grain filling characteristics have been more, but the study on the grain filling characteristics of different nitrogen-efficient wheat varieties is relatively less. Based on the previous research, this study selected three types of wheat varieties, high yield and nitrogen efficiency, high yield and low nitrogen efficiency, and low yield and low nitrogen efficiency, and systematically compared the grain filling characteristics of different types of wheat varieties and their relationship with yield and nitrogen efficiency under field production conditions, in order to provide a theoretical basis for variety breeding and high yield and nitrogen reduction cultivation in the region.

[0003] Therefore, it is an urgent problem for those skilled in the art to provide a wheat yield and nitrogen absorption efficiency comprehensive identification model, method and application.

[0004] SUMMARY

[0005] Therefore, the present application provides a wheat yield and nitrogen absorption efficiency comprehensive identification model, method and application.

[0006] In order to achieve the above purpose, the present application adopts the following technical scheme: a wheat yield and nitrogen absorption efficiency comprehensive identification method, comprising the following steps:

[0007] (1) Population dynamics and yield determination:

[0008] After emergence, 1 meter double row marks with uniform growth were selected in each plot, tillering situation was counted at tillering stage and green stage, and ear number and grain number per ear were counted at maturity stage, and effective ear rate was calculated;

[0009] Effective ear rate (%) = unit area effective ear number / unit area tiller number x 100;

[0010] Grain filling rate (mg / d / grain) = grain dry matter increase mass (mg) ÷ corresponding interval days (d) of each determination;

[0011] Grain yield: 1x1=1m 2 sample plot, artificial harvesting and threshing, natural drying and weighing, calculating grain yield per hectare, and determining thousand grain mass;

[0012] (2) Grain filling characteristics determination

[0013] 100 ears with consistent flowering stage were selected in each plot and marked, and after the end of flowering, 1 sample was taken every 5 days, a total of 7 times, i.e. 5, 10, 15, 20, 25, 30, 35 days after flowering, 10 ears with marked signs were randomly taken from each test plot every time, artificial threshing, killing green at 105℃ for 20 min, constant temperature drying at 75℃ until constant weight, weighing with one ten-thousandth balance and converting to thousand grain weight;

[0014] (3) Grain filling parameter calculation: taking days after flowering t as independent variable and corresponding thousand grain weight Y measured at time t as dependent variable, using Logistic equation to simulate grain growth process; Y=A / (1+Be -Kt )

[0015] In the formula, A represents the final value of growth (thousand grain weight at the end of grain filling), B and K are model parameters, and the equation fitting condition is represented by determination coefficient R2; the first and second derivatives of Logistic equation can obtain time equation V(t) of grain filling rate, maximum grain filling rate Vmax and its occurrence time Tmax, growth amount Ymax at the maximum grain filling rate, average grain filling rate, and the duration of increasing period, fast increasing period and slow increasing period (T1, T2, T3); V t =ABKe -Kt / (1+Be -Kt ) 2 V max =AK / 4 T max =(InB) / K

[0016] 2 inflection points on the grain filling rate equation; t1=-In[(2+±√3 -) / B / K t2=-In[(2+3) / B] / K

[0017] Grouting end time: t3=-[In(100 / 98-1) / B] / K;

[0018] The data are arranged and analyzed by Excel 2010, the regression analysis is carried out by SPSS18.0 software, and the equation fitting and drawing are carried out by OriginPro 8.5;

[0019] (4) Result analysis:

[0020] The wheat grain filling process is divided into the early filling stage (slow increasing stage), the middle filling stage (fast increasing stage) and the late filling stage (slow stage) by using Logistics equation, and the grain filling characteristics of the three stages are different among different types of varieties.

[0021] Before the maximum filling rate, the filling rate curves of the three varieties are arranged from top to bottom as HH, HL and LL; after reaching the maximum filling rate, the filling rate curves are arranged from top to bottom as LL, HL and HH; in the slow increasing stage, the fast increasing stage and the slow stage, the average filling rate of each stage is HH>HL>LL.

[0022] Before the maximum filling rate, the filling rate curves of the three varieties are arranged from top to bottom as HH, HL and LL;

[0023] After reaching the maximum filling rate, the filling rate curves are arranged from top to bottom as LL, HL and HH.

[0024] In the slow increasing stage, the fast increasing stage and the slow stage, the average filling rate of each stage is HH>HL>LL.

[0025] The application further provides a wheat yield and nitrogen absorption efficiency comprehensive identification method in the determination of wheat yield and nitrogen absorption efficiency.

[0026] Through the above technical solution, compared with the prior art, the beneficial effects of the present application are:

[0027] (1) The dynamic growth process of the thousand-grain weight of different nitrogen efficiency wheat conforms to the Logistics model, but the model parameters such as the ultimate grain growth and the initial grain growth rate are different, and the filling rate difference among varieties is significant. The filling rate of the high-yield and high-nitrogen efficiency wheat variety is fast, and the thousand-grain weight is high.

[0028] (2) The yield, nitrogen physiological utilization efficiency and nitrogen absorption efficiency of high yield and high nitrogen efficiency wheat varieties were significantly higher than those of high yield and low nitrogen efficiency and low yield and low nitrogen efficiency wheat varieties. The yield and nitrogen physiological utilization efficiency were significantly or extremely significantly correlated with the grain filling characteristic parameters; among them, the nitrogen absorption efficiency was significantly positively correlated with the maximum filling rate and the thousand-grain weight at the maximum filling rate, and was significantly negatively correlated with the filling duration. BRIEF DESCRIPTION OF DRAWINGS

[0029] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings needed to be used in the embodiments or prior art description will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor on the basis of the provided drawings.

[0030] Figure 1 is a grain filling Logistics fitting curve and filling rate-time change graph under different treatments (2019-2020);

[0031] Figure 2 is a grain filling Logistics fitting curve and filling rate-time change graph under different treatments (2020-2021). DETAILED DESCRIPTION

[0032] The technical solutions in the embodiments of the present application will be described clearly and completely below in combination with the drawings in the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, not all. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the present application.

[0033] Embodiment 1

[0034] 1. Materials and methods

[0035] Test materials

[0036] According to the research results in 2017-2018, high yield and high nitrogen efficiency varieties (HH), high yield and low nitrogen efficiency varieties (HL) and low yield and low nitrogen efficiency varieties (LL) were screened out, which were Zhengmai 1860, Fengdeshun 5 and Zhengpinmai 8, respectively.

[0037] 1.2 Experimental design

[0038] 1.2.1 Test site overview

[0039] The test was set up at the National Long-term Monitoring Test Station of Soil Fertility and Fertilizer Efficiency (113°41'E, 35°00'N). The base is located in the Huanghuaihai Plain, in the transition zone from tropical to warm temperate zone, belongs to the continental monsoon climate, the average annual precipitation is 645 mm, the average sunshine is 12 h, the average temperature is 14.4℃, and the frost-free period is 224 d. The test soil is chao soil, the soil fertility is uniform, the soil basic fertility of 0-30 cm plough layer is: organic matter content 14.26 g·kg -1 , alkali hydrolysis nitrogen content 81.4 mg·kg -1 , available phosphorus content 14.1 mg·kg -1 , available potassium content 88.4 mg·kg -1 , total nitrogen content 0.8 g·kg -1 .

[0040] 1.2.2 Test setup

[0041] The test was carried out in 2019-2021, sowing in mid-October each year, and harvesting in June the next year, with a sowing amount of 150 kg·hm -2 . A split-plot design was used, with nitrogen fertilizer treatment as the main plot and variety as the sub-plot. The nitrogen level was 2: no nitrogen fertilizer N0 (0 kg N·hm -2 ), normal nitrogen fertilizer N1 (165 kg N·hm -2 ). The test plot was randomly arranged, with an area of 6 x 9 = 54 m 2 , row spacing 20 cm, repeated 3 times. The nitrogen fertilizer used was urea (containing N 46%), phosphorus fertilizer was calcium dihydrogen phosphate (containing P2O5 12%) 687.5 kg·hm -2 , potassium fertilizer was potassium sulfate (containing K2O 57%) 144.7 kg·hm -2 . The nitrogen fertilizer base and top-up ratio was 1:1, the top-up was applied in the ditch at the green stage, the phosphorus fertilizer and potassium fertilizer were applied as base fertilizer before sowing, and other cultivation measures were the same as general high-yield field management.

[0042] 1.3 Measuring indicators and methods

[0043] 1.3.1 Population dynamics and yield determination

[0044] After emergence, 1 meter double row marks with uniform growth were selected in each plot, tillering was counted at tillering stage and green stage, ear number and grain number per ear were counted at maturity, and effective ear rate was calculated.

[0045] Effective ear rate (%) = unit area effective ear number / unit area tillering number x 100.

[0046] Grain filling rate (mg / d / grain) = grain dry matter increased mass (mg) per determination ÷ corresponding determination interval days (d)

[0047] Grain yield: 1 m2 per plot at maturity 2 Quadrat, artificial harvesting, threshing, natural drying, weighing, calculating grain yield per hectare, measuring thousand grain mass.

[0048] 1.3.2 Grain filling characteristics determination

[0049] Select 100 spikes with consistent flowering period per plot and mark with a label. Start on the 5th day after flowering ends, take samples every 5 days, a total of 7 times, i.e. 5, 10, 15, 20, 25, 30, 35 days after flowering, randomly select 10 spikes with label marks in each test plot each time, manually thresh, kill green at 105°C for 20 min, dry at 75°C to constant weight, weigh with a millionth balance and convert to thousand grain weight.

[0050] 1.3.3 Plant total nitrogen content

[0051] Grind the above-ground dry sample in 1.3.2, use H2SO4-H2O2 digestion method (salicylic acid-zinc powder reduction method, titration after distillation) to determine plant total nitrogen content. N = (V x 0.05 x 14 x 100) / (1000 x M)

[0052] In the formula: N is the nitrogen content of the plant (%); V is the volume variable of hydrochloric acid (ml); M is the sample mass (g).

[0053] Plant nitrogen accumulation (kg·hm -2 ) = total nitrogen content x plant above-ground biomass.

[0054] Nitrogen absorption efficiency = (plant nitrogen accumulation in nitrogen application area - plant nitrogen accumulation in non-nitrogen application area) / nitrogen application amount x 100%.

[0055] Nitrogen physiological utilization efficiency = (yield in nitrogen application area - yield in non-nitrogen application area) / (plant nitrogen accumulation in nitrogen application area - plant nitrogen accumulation in non-nitrogen application area) x 100%.

[0056] 1.4 Data processing

[0057] Grain filling parameter calculation: take the number of days after flowering t as the independent variable, and the measured thousand grain weight Y corresponding to a certain time t as the dependent variable, use the Logistic equation to simulate the grain growth process. Y = A / (1 + Be -Kt )

[0058] Where A represents the final value of growth (thousand-grain weight at the end of grain filling), B and K are model parameters, and the equation fitting is represented by the determination coefficient R2. The first and second derivatives of the Logistic equation can be used to obtain the time equation of grain filling rate V(t), the maximum grain filling rate Vmax and its occurrence time Tmax, the growth amount Ymax at the maximum grain filling rate, the average grain filling rate, and the duration of the gradual increase period, the fast increase period, and the slow increase period (T1, T2, T3). t = ABKe -Kt / (1+Be -Kt ) 2 V max =AK / 4 T max =(InB) / K

[0059] Two inflection points on the grain filling rate equation t1=-In[(2+±√3 - ) / B / K t2=-In[(2+3) / B] / K

[0060] The end time of grain filling t3=-[In(100 / 98-1) / B] / K.

[0061] The data were arranged and analyzed using Excel 2010, the regression analysis was performed using SPSS 18.0 software, and the equation fitting and mapping were performed using OriginPro 8.5.

[0062] Results and Analysis

[0063] 2.1 Analysis of Logistic model parameters of different types of wheat

[0064] The dynamic growth process of the thousand-grain weight of winter wheat was fitted by the Logistics model, the fitting equation and the determination coefficient are shown in Table 1, and the grain growth process is shown in Figure 1. As shown in Table 1 and Figure 1-A, the determination coefficients R2 of the fitting process were all greater than 0.99, reaching a highly significant level, indicating that the Logistics equation can well simulate the grain filling process of winter wheat, and the fitting curves of the grain filling process all showed a “slow-fast-slow” growth trend.

[0065] The final growth amount A of HH grain was higher than that of LL grain between two years, and the trend of final growth amount of different types of wheat varieties was HH > HL > LL in 2019-2020 (see Table 1, parameter A), and HL > HH > LL in 2020-2021. Compared with LL, the theoretical thousand-grain weight of HH increased by 2.21 g and 3.1 g (P < 0.05) than HL and LL in 2019-2020; in 2020-2021, HH and HL had no significant difference, and increased by 2.5 g and 2.7 g (P < 0.05) than LL, respectively; the difference between HL and LL was not significant. It showed that HH had greater yield potential and better high yield, and was suitable for planting in high-fertilizer and high-water growth conditions.

[0066] The initial parameter (B) represents the growth potential of the ovary after fertilization, and the larger the B value, the faster the endosperm cell division, the shorter the division cycle, and the faster the initial growth rate of the grain. The B value of HH (53.225-56.159) was significantly higher than that of HL and LL (45.245-52.607). The parameter K of grain filling rate also showed HH > HL > LL, and there was a significant difference between varieties.

[0067] Table 1 Logistics model parameters under different treatments

[0068] 2.2 Grain filling characteristic parameters of different types of wheat

[0069] As can be seen from Table 2, there are obvious differences in the grain filling characteristics of the tested varieties calculated according to the Logistics model. The average duration of grain filling of HH is 34.318 days, which is shortened by 4.408 days compared with HL and 7.613 days compared with LL. The active grain filling period is also shortened by 2.460 days and 4.350 days compared with HL and LL. The grain filling rate trends of two years are the same, first increasing and then decreasing, and the curve vertex corresponds to the Vmax and Tmax values in Table 2 (Figure 1-B). The average grain filling rate of HH within 35 days after flowering is 0.739 g / d, which is significantly higher than that of HL and LL 0.095 g / d and 0.167 g / d; the maximum grain filling rate of HH appears at 17.356 days and 17.438 days after flowering, which is 2.015 days and 3.382 days earlier than that of HL and LL, respectively. The active grain filling period of HH is also significantly 2.460-4.350 days earlier than that of HL and LL.

[0070] Table 2 Grain filling characteristic parameters of winter wheat under different treatments Note: T-duration of grain-filling, Vmax-maximum grain-filling rate, Tmax-time reaching the maximum grain-filling rate, Ymax-weight of grain at the time of maximum grain-filling rate, V(g / d)-mean grain-filling rate.

[0071] 2.3 Distribution characteristics of different types of wheat grain-filling at each stage

[0072] The grain-filling process of wheat was divided into three stages: early grain-filling stage (slowly increasing stage), mid grain-filling stage (rapidly increasing stage) and late grain-filling stage (slowly stage) by using Logistics equation. As shown in Fig. 1, the characteristics of grain-filling in the three stages were different among different types of varieties. Before the maximum grain-filling rate, the grain-filling rate curves of the three varieties were HH on the top, HL in the middle and LL on the bottom. After reaching the maximum grain-filling rate, the grain-filling rate curves were LL, HL and HH from top to bottom. However, in the slowly increasing stage, rapidly increasing stage and slowly stage, the average grain-filling rate of each stage was HH > HL > LL. Due to the difference in varieties, the grain-filling time was different. The duration of the rapidly increasing stage of LL was 2.024 days and 0.819 days longer than that of HL and HH, respectively; the duration of the slowly stage was 2.800 days and 1.217 days longer than that of HL and HH, respectively (Table 3).

[0073] Table 3 Characteristics of grain-filling in three stages Note: T1-slow grain-filling period, T2-rapid grain-filling period, T3-slow grain-filling period.

[0074] 2.4 Yield and nitrogen use efficiency of different types of wheat varieties

[0075] The yield and nitrogen use efficiency of different types of wheat varieties in 2019-2020 and 2020-2021 showed the same trend (Table 4). Taking the results of 2019-2020 as an example, the yield of HH and HL was significantly higher than that of LL by 29.38% and 15.16%, respectively; the nitrogen physiological utilization efficiency was significantly increased by 20.65% and 7.79%, respectively; the nitrogen absorption efficiency was significantly increased by 55.04% and 9.45%, respectively; as high-yield varieties, the yield, nitrogen physiological utilization efficiency and nitrogen absorption efficiency of HH were significantly higher than those of HL by 12.35%, 11.93% and 33.24%, respectively.

[0076] Table 4 Yield and nitrogen use efficiency of different types of wheat varieties Note: Different lowercase letters in the same column indicate that the difference between different varieties in the same year is statistically significant at the P<0.05 level.

[0077] 2.5 Yield components of different types of wheat varieties

[0078] The yield components of different wheat varieties showed some differences (Table 5). In 2019-2020, compared with LL, the number of grains per spike and the number of effective spikes of HH were significantly increased by 9.76% and 7.23%, respectively, and the increase of HL was not obvious; the effective spike rate of HH and LL was significantly higher than that of HL by 21.39% and 10.34%, respectively; the thousand-grain weight of HH was significantly higher than that of HL and LL by 11.76% and 6.24%, respectively, and the difference between HL and LL was not obvious. The results of yield components of different varieties in 2020-2021 showed the same trend.

[0079] Table 5 Yield components and factors of different types of wheat varieties Note: Different lowercase letters in the same column indicate that the difference between different varieties in the same year is statistically significant at the P<0.05 level.

[0080] 2.6 Grain filling characteristics of different types of wheat varieties and the relationship between yield, nitrogen use efficiency and grain filling characteristics

[0081] The results of correlation analysis of yield, nitrogen use efficiency and grain filling characteristics of different types of wheat varieties showed (Table 6) that,

[0082] Yield and nitrogen physiological utilization efficiency were significantly or extremely significantly correlated with grain filling characteristics parameters, and were extremely significantly positively correlated with Vmax and Vmean, significantly positively correlated with Ymax, and extremely significantly negatively correlated with T(d) and Tmax; nitrogen absorption efficiency was significantly positively correlated with Vmax and Ymax, extremely significantly positively correlated with Vmean, and extremely significantly negatively correlated with T(d) and Tmax.

[0083] Table 6 Correlation of grain filling characteristics with yield, nitrogen absorption efficiency and nitrogen physiological efficiency Note: * and ** represent statistical significance at P<0.05 and P<0.01 levels, respectively.

[0084] Discussion

[0085] 3.1 Grain filling characteristics and wheat yield formation

[0086] Wheat yield is composed of ear number, grain number per ear and 1000-grain weight. In this study, the yield and three elements of different types of wheat varieties were analyzed, and it was found that the key to high yield of wheat was the size of 1000-grain weight when the ear number and grain number per ear were constant. This was similar to the research results of Yang Jinyu and Wang Lina.

[0087] Grain filling period is the key growth period for wheat to increase grain weight and improve yield. Yield is greatly affected by dry matter accumulation during grain filling. In this experiment, the dry matter weight of different types of varieties after flowering showed S-type curve growth with the advancement of grain filling time, and the grain filling process was well fitted by Logistics equation, which truly reflected the grain filling process of wheat. This was consistent with the research results of Yang Jinyu. Different genotypes of varieties have different grain filling characteristics. Previous studies have shown that the yield and grain filling characteristics of different types of wheat are related to the genotype and consistent environment of cultivation. Guo Yanyan believed that wheat grain weight was mainly determined by the maximum grain filling rate. Li Ziyuan believed that grain weight was mainly related to the duration of grain filling. Due to differences in varieties, climate and cultivation conditions, the conclusions of scholars were not consistent. In this study, through the study of high-yield nitrogen-efficient, high-yield nitrogen-inefficient, and low-yield nitrogen-inefficient wheat varieties, it was found that the grain filling of high-yield nitrogen-efficient wheat varieties started early, filled rapidly, and the final grain growth was the largest. This further verified the research results of Li Min et al.

[0088] 3.2 Analysis of the synergistic formation of high yield and nitrogen efficiency of wheat based on grain filling characteristics

[0089] The results showed that the nitrogen efficiency of different genotypes of the same high-yielding wheat variety was significantly different. Nitrogen efficiency mainly refers to nitrogen absorption and utilization efficiency. The difference in nitrogen absorption and utilization efficiency exists not only between different species, but also between different varieties of the same species. The results of two years of research showed that, under the same high-yielding cultivation measures, the yield of nitrogen-efficient varieties was significantly higher than that of nitrogen-inefficient varieties, and the nitrogen absorption and utilization efficiency was significantly correlated with the yield. Many studies have shown that grain filling affects yield formation and nitrogen absorption and utilization. It is not only the process of photosynthetic products transportation, assimilation and accumulation, but also the process of nitrogen allocation, transportation and recombination to grains. High-yielding nitrogen-efficient genotypes usually have high nitrogen absorption and utilization capacity, that is, strong nitrogen transportation and recombination capacity. The grain filling and filling characteristics of HH (high yield and high nitrogen efficiency) were higher than those of HL (high yield and low nitrogen efficiency) and LL (low yield and low nitrogen efficiency). Therefore, the filling and filling characteristics may be an important reason for limiting the further improvement of nitrogen absorption and utilization rate, and thus affecting the yield of wheat.

[0090] The main reason for poor grain filling and filling is the large capacity of the variety and the lack of filling material. For example, HH and HL are both high-yielding wheat varieties. Due to the low nitrogen efficiency of HL, its root system's ability to absorb nitrogen and photosynthetic production capacity will decrease in the late growth period, and it is difficult to meet the needs of large-capacity filling, resulting in a lag in grain filling time, a decrease in grain filling rate, and a decrease in effective ear rate and grain weight. However, high-yielding nitrogen-efficient varieties have high root activity, high nitrogen accumulation, and strong photosynthetic capacity in the late growth period, forming a balanced system of efficient utilization of photosynthetic substances and nitrogen nutrition, which not only promotes grain filling and filling, but also promotes the efficient absorption and utilization of nitrogen. The results of this study also confirm this point.

[0091] Wheat in Henan Province is easily affected by drought, dry and hot wind and other climate conditions during the grain filling period, resulting in a decrease in grain filling rate, a decrease in effective grain filling time, and a decrease in thousand-grain weight. Therefore, when selecting varieties, high-yielding nitrogen-efficient wheat varieties with early grain filling start time and fast grain filling rate should be considered.

[0092] Conclusion

[0093] (1) The dynamic growth process of thousand-grain weight of different nitrogen-efficient wheat varieties conforms to the Logistics model, but the model parameters such as grain ultimate growth and initial growth rate are different, and the grain filling rate is significantly different between varieties. High-yielding nitrogen-efficient wheat varieties have early grain filling start time, fast grain filling rate, and high thousand-grain weight.

[0094] (2) The yield, nitrogen physiological utilization efficiency and nitrogen absorption efficiency of high yield and high efficiency wheat varieties were significantly higher than those of high yield and low efficiency and low yield and low efficiency wheat varieties. The yield and nitrogen physiological utilization efficiency were significantly or extremely significantly correlated with the grain filling characteristics parameters. The nitrogen absorption efficiency was significantly positively correlated with the maximum filling rate and the thousand-grain weight at the maximum filling rate, and significantly negatively correlated with the filling duration.

[0095] The above description of disclosed embodiments enables one of ordinary skill in the art to make or use the application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein can be applied to other embodiments without departing from the spirit or scope of the application. Thus, the present application is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for comprehensive evaluation of wheat yield and nitrogen uptake efficiency, characterized in that, Comprising the following steps: (1) Population dynamics and yield determination: After emergence, 1 meter double row markers with uniform growth were selected in each plot, tillering was counted at tillering stage and green stage, and ear number and grain number per ear were counted at maturity, and effective ear rate was calculated; Effective ear rate (%) = unit area effective ear number / unit area tiller number x 100; Grain filling rate (mg / d / grain) = grain dry matter increase mass (mg) ÷ corresponding interval days (d); Grain yield: 1 x 1 = 1 m2 per plot at maturity 2 Quadrats, artificial harvesting, natural drying, weighing, calculating grain yield per hectare, measuring thousand-grain mass; (2) Grain filling characteristics determination 100 ears were selected in each plot and marked at consistent flowering stage, 1 sample was taken every 5 days after 5 days after flowering, a total of 7 times, i.e. 5, 10, 15, 20, 25, 30, 35 days after flowering, 10 ears with marked signs were randomly selected in each test plot every time, artificial threshing was performed, and the grains were killed at 105°C for 20 min, and then dried at 75°C to constant weight, and weighed with a hundredth balance and converted to thousand-grain weight; (3) Grain filling parameter calculation: take the post-flowering days t as the independent variable, and the thousand-grain weight Y measured at a certain time t as the dependent variable, use the Logistic equation to simulate the grain growth process; Y = A / (1 + Be -Kt ) In the formula, A represents the final value of growth (thousand-grain weight at the end of grain filling), B and K are model parameters, and the equation fitting condition is represented by the determination coefficient R2; the first derivative and the second derivative of the Logistic equation are obtained, and the time equation V(t) of the grain filling rate, the maximum grain filling rate Vmax and its occurrence time Tmax, the growth Ymax at the maximum grain filling rate, the average grain filling rate, the duration of the increasing period, the fast increasing period and the slow increasing period (T1, T2, T3) are obtained; V t = ABKe -Kt / (1+Be -Kt ) 2 V max = AK / 4 T max = (In B) / K Two inflection points on the grain filling rate equation; t2 = -In[(2+3) / B] / K Grain filling end time: t3 = -[In(100 / 98-1) / B] / K; The data were arranged and analyzed by Excel 2010, regression analysis was performed by SPSS18.0 software, equation fitting and mapping were performed by OriginPro 8.5; (4) Result analysis.

2. The application of the wheat yield and nitrogen absorption efficiency comprehensive identification method of claim 1 in the determination of wheat yield and nitrogen absorption efficiency.

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