A method for quickly predicting the rice heading date

Abstract

The application discloses a method for quickly predicting the initial heading stage of rice. The method belongs to the technical field of rice cultivation. The method constructs a mathematical model formula according to the light-temperature adaptability level of rice varieties, quantifies the light-temperature adaptability level of the rice varieties through planting in three test points with different latitudes, and can not only cross-regionally predict, but also cross-periodically predict after quantification, thereby effectively improving the prediction accuracy, saving time and labor, and providing technical support for commercial breeding and market popularization of the rice.

Description

Technical Field

[0001] The invention relates to the technical field of rice cultivation, and more particularly to a method for rapidly predicting the rice heading stage. Background Art

[0002] Rice is one of the world's most important food crops, playing a vital role in modern agricultural production and social development. Heading date is a key agronomic trait of rice. The length of the heading date directly reflects the length of the rice variety's growing season, which in turn affects photosynthesis and biomass accumulation, ultimately directly or indirectly affecting rice yield. The heading date also determines the regional and seasonal adaptability of a rice variety. Therefore, the heading date is a crucial factor in determining a rice variety's regional and seasonal adaptability, as well as its yield. In practical production and basic research, the more accurate heading date is often used instead of the heading date. Therefore, predicting the heading date plays a crucial role in the screening and promotion of rice varieties.

[0003] At present, the prediction of rice heading date is mainly based on multi-environment planting. Through manual experience, the heading date phenotype in adjacent areas and different sowing periods is roughly estimated. However, this method cannot quantify the impact of light and temperature factors on the heading date, the prediction accuracy is limited, and direct prediction across ecological regions cannot be achieved. In addition, at least 3-5 representative test points must be selected in an ecological region, and then 2-3 different sowing periods must be selected for each test point. Only in this way can the basic adaptability level of the variety in this ecological region be preliminarily determined. If cross-ecological planting is to be achieved, 3-5 test points and 2-3 different sowing periods must be selected in the target ecological region, which is labor-consuming and time-consuming, and the investment cost is relatively high.

[0004] Therefore, providing a method that can quantify the light and temperature adaptability level of rice varieties and predict the rice heading date across ecological regions and sowing periods is a technical problem that those skilled in the art urgently need to solve. Summary of the Invention

[0005] In view of this, the present invention provides a method for quickly predicting the heading date of rice. In the method, a mathematical model formula is constructed for the light and temperature adaptability levels of rice varieties. The light and temperature adaptability levels of rice varieties are quantified through planting in three environments. After quantification, the accuracy of prediction can be improved, and the heading date of rice can be predicted across regions and sowing periods.

[0006] In order to achieve the above object, the present invention adopts the following technical solutions:

[0007] A method for rapidly predicting the heading date of rice comprises the following steps:

[0008] (1) Determination of planting areas: Three regions with different latitudes, namely, middle, low and high, were selected as rice planting test sites for rice planting;

[0009] (2) Determination of the heading date: The heading date phenotypes of rice grown for many years at the test site described in step (1) were integrated to obtain the average heading date H of rice varieties at the three test sites. n (d);

[0010] (3) Determination of average temperature and average sunshine time: The meteorological temperature and sunshine time of the test site for many years from the 26th to the 70th day after rice sowing in step (1) were integrated to obtain the average temperature T of the three test sites from the 26th to the 70th day after rice sowing. n (℃) and average sunshine time L n (h);

[0011] (4) The average earing period H of the three test points in step (2) and step (3) is calculated as follows: n , average temperature T n (℃) and average sunshine time L n (h) Substitute the mathematical modeling formula to calculate the photosensitivity index (PSI) and temperature sensitivity index (TSI) of rice varieties;

[0012] The mathematical modeling formula is as follows:

[0013] H1=H 低纬 , H 2＝ H 中纬 , H 3＝ H 高纬 , H 4＝ H 待预测 ;

[0014] H2=H1+H2×PSI×(L2-L1) / L2-H2×TSI×(T2-T1) / T2;

[0015] H3=H1+H3×PSI×(L3-L1) / L3-H3×TSI×(T3-T1) / T3;

[0016] H4=H1+H4×PSI×(L4-L1) / L4-H4×TSI×(T4-T1) / T4;

[0017] (5) Combine the photosensitivity index (PSI) and temperature sensitivity index (TSI) of the rice variety obtained in step (3) and the average temperature T of the rice to be predicted on the 26th to 70th day after sowing. n (℃) and average sunshine time L n (h) Predict the heading date of the rice variety in different regions and sowing periods.

[0018] Preferably, the low-latitude region in step (1) is Sanya; the mid-latitude region is Hangzhou; and the high-latitude region is Shenyang.

[0019] Preferably, the heading stage in step (2) is recorded as the heading stage when 10% of the main panicles begin to sprout.

[0020] Preferably, the rice planting process in step (1) is as follows: in Hangzhou, sowing on May 25, with a plant spacing of 6 inches by 8 inches; in Shenyang, sowing on April 20, with a plant spacing of 7 inches by 9 inches; and in Sanya, sowing on December 5, with a plant spacing of 6 inches by 7 inches.

[0021] According to the technical solution described above, compared with the prior art, the present application has the following beneficial effects:

[0022] The present application determines an effective quantitative light and temperature factor analysis model for the light and temperature adaptability level of rice varieties, quantifies the light and temperature adaptability level of rice varieties through planting in three different latitude test points, can not only predict across regions after quantization, but also predict across sowing periods, the correlation coefficient R of the prediction results and the actual results is as high as 0.973 and 0.982, the overall error is controlled at an average of 6.55 days and 4.93 days, effectively improves the accuracy of the prediction, saves time and effort, and provides technical support for commercial breeding and market promotion of rice. BRIEF DESCRIPTION OF DRAWINGS

[0023] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or the prior art description. Obviously, the drawings in the following description are only some embodiments of the present application, and for those skilled in the art, other drawings can be obtained without creative labor on the basis of the provided drawings.

[0024] Figure 1 The drawing is: prediction effect diagram of heading stage in Hangzhou-20190625;

[0025] Figure 2 The drawing is: prediction effect diagram of heading stage in Chongqing-20200313. DETAILED DESCRIPTION

[0026] The technical solutions in the embodiments of the present application will be described in detail below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only some embodiments of the present application, not all embodiments. 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.

[0027] Embodiment 1

[0028] (1) 185 representative rice varieties from different regions were selected and named S1-S185 (including 113 japonica rice and 72 indica rice), which were planted in Fuyang, Hangzhou, Sanya, Hainan and Shenyang, Liaoning, respectively, and the planting dates were as follows:

[0029] Fuyang, Hangzhou (Hangzhou-0525): May 25, 2012, May 25, 2013 and May 25, 2017;

[0030] Sanya, Hainan (Sanya-1205): December 5, 2012, December 5, 2015 and December 5, 2017;

[0031] Shenyang, Liaoning (Shenyang-0420): April 20, 2016, April 20, 2017.

[0032] (2) The heading dates (phenotype of heading date) of different varieties in the above three test sites for many years were integrated together to obtain the average heading date of different varieties in the three test sites, and the results are shown in Table 1;

[0033] (3) The meteorological temperature and sunshine duration from the 26th to the 70th day after sowing in the above three test sites for many years were integrated together to obtain the average temperature T n (℃) and average sunshine duration L n (h) of the three test sites, and the results are shown in Table 2.

[0034] (3) The average heading date of different varieties in different test sites obtained in step (2); the average temperature T n (℃) and average sunshine duration L n (h) of different test sites obtained in step (2) were substituted into the mathematical modeling formula to calculate the corresponding photoperiod sensitivity index and thermosensitivity index of 185 different rice varieties, and the results are shown in Table 1.

[0035] (4) The above 185 rice varieties were planted in Hangzhou (sowing date: June 25, 2019, referred to as Hangzhou-20190625) and Chongqing (sowing date: March 13, 2020, referred to as Chongqing-20200313), and the actual phenotype of the heading date (heading date) and the average temperature and average sunshine duration from the 26th to the 70th day after sowing were investigated, and the results are shown in Table 1 and Table 2.

[0036] (5) According to the simulation formula, the heading dates of the 185 materials in Hangzhou and Chongqing were predicted, and then the prediction results were compared with the actual observation results in the two places, and the results are shown in Figure 1 and Figure 2 the accompanying drawings, respectively.

[0037] Table 1: Phenotypes at the beginning of heading stage at each test site and light and temperature sensitivity indexes of each variety

[0038]

[0039]

[0040]

[0041]

[0042]

[0043] Table 2: Average temperature and average sunshine time at each test site from 26th to 70th day after sowing

[0044] Test Point Average sunshine time / h Average temperature / ℃ Sanya-1205 11.234 20.630 Hangzhou-0525 13.924 29.510 Shenyang-0420 15.086 21.390 Hangzhou-20190625 13.342 29.340 Chongqing-20200313 13.253 21.190

[0045] Result analysis: The results showed that by applying this method to predict the heading date phenotypes of Hangzhou-20190625 and Chongqing-20200313, the correlation coefficients R reached 0.973 and 0.982, respectively, and the overall errors were controlled within an average of 6.55 days and 4.93 days, respectively, achieving the expected purpose.

[0046] The various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referenced to each other.

[0047] The above description of the disclosed embodiments is intended to enable one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be readily apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not limited to the embodiments shown herein but is intended to conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for rapidly predicting the heading date of rice, characterized in that: The steps include: (1) Determination of planting areas: Selecting three areas with different latitudes, namely, middle, low and high, as rice planting test sites for rice planting; (2) Determination of the heading date: The heading date phenotypes of rice grown for many years at the test site described in step (1) were integrated to obtain the average heading date H of rice varieties at the three test sites. n , d; (3) Determination of average temperature and average sunshine time: The meteorological temperature and sunshine time of the test site in step (1) on the 26th to 70th day after rice sowing were integrated to obtain the average temperature T of the three test sites on the 26th to 70th day after rice sowing. n ,℃ and average sunshine time L n , h; (4) The average earing date H of the three test points in steps (2) and (3) is calculated as n , d, average temperature T n ,℃ and average sunshine time L n , h, substituted into the mathematical modeling formula to calculate the photosensitivity index PSI and temperature sensitivity index TSI of rice varieties; The mathematical modeling formula is as follows: H1=H 低纬 ,H2=H 中纬 ,H3=H 高纬 ,H4=H 待预测 ; H2=H1+H2×PSI×(L2-L1) / L2-H2×TSI×(T2-T1) / T2; H3=H1+H3×PSI×(L3-L1) / L3-H3×TSI×(T3-T1) / T3; H4=H1+H4×PSI×(L4-L1) / L4-H4×TSI×(T4-T1) / T4; Combined with the photosensitivity index PSI and temperature sensitivity index TSI of the rice variety obtained in step (4), and the average temperature T of the rice to be predicted 26-70 days after sowing, n ,℃ and average sunshine time L n ,h, predict the heading date of the rice variety in different regions and sowing periods.

2. The method for rapidly predicting the rice heading date according to claim 1, wherein: The low-latitude region mentioned in step (1) is Sanya; the mid-latitude region is Hangzhou; and the high-latitude region is Shenyang.

3. The method for rapidly predicting the rice heading date according to claim 1, wherein: The initial earing stage described in step (2) is recorded as the initial earing stage when 10% of the main ears begin to emerge.

4. The method for rapidly predicting the rice heading date according to claim 2, wherein: The rice planting processes in step (1) are as follows: in Hangzhou, sowing was carried out on May 25, with a row spacing of 6 inches × 8 inches; in Shenyang, sowing was carried out on April 20, with a row spacing of 7 inches × 9 inches; and in Sanya, sowing was carried out on December 5, with a row spacing of 6 inches × 7 inches.

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