Method for rapidly predicting initial heading stage of rice

Abstract

Disclosed is a method for rapidly predicting the initial heading stage of rice. The present invention belongs to the technical field of rice cultivation. The method in the present invention builds a mathematical model formula for the light temperature adaptability level of a rice variety, and quantizes the light temperature adaptability level of the rice variety by means of planting at three test points of different latitudes. The quantization allows for not only trans-regional prediction, but also cross-seedtime prediction, effectively improving prediction accuracy, saving much time and labor, and providing technical support for commercial breeding and market promotion of rice.

Description

A method for quickly predicting rice heading date 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.

[0005] Summary of the Invention

[0006] 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.

[0007] In order to achieve the above object, the present invention adopts the following technical solutions:

[0008] A method for rapidly predicting the heading date of rice comprises the following steps:

[0009] (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;

[0010] (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);

[0011] (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);

[0012] (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;

[0013] The mathematical modeling formula is as follows: H1=H 低纬 , H 2＝ H 中纬 , H 3＝ H 高纬 , H 4＝ 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;

[0014] (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.

[0015] Preferably, the low-latitude region in step (1) is Sanya; the mid-latitude region is Hangzhou; and the high-latitude region is Shenyang.

[0016] Preferably, the initial earing stage in step (2) is when 10% of the main ears begin to emerge.

[0017] Preferably, the rice planting process in step (1) is as follows: in Hangzhou, sowing is carried out on May 25, with a row spacing of 6 inches × 8 inches; in Shenyang, sowing is carried out on April 20, with a row spacing of 7 inches × 9 inches; and in Sanya, sowing is carried out on December 5, with a row spacing of 6 inches × 7 inches.

[0018] It can be seen from the above technical solutions that compared with the prior art, the present invention has the following beneficial effects:

[0019] The present invention determines an effective analytical model for quantifying light and temperature factors for the light and temperature adaptability levels of rice varieties. By planting at three test sites at different latitudes, the light and temperature adaptability levels of rice varieties are quantified. After quantification, not only can cross-regional predictions be made, but also cross-sowing period predictions can be made. The correlation coefficients R between the predicted results and the actual results are as high as 0.973 and 0.982, and the overall errors are controlled at an average of 6.55 days and 4.93 days, respectively. This effectively improves the accuracy of the prediction, saves time and effort, and provides technical support for the commercial breeding and market promotion of rice. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are merely embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying any creative work.

[0021] Figure 1 is a diagram showing the predicted effect of the heading period in Hangzhou on June 25, 2019;

[0022] Figure 2 shows the predicted effect of the ear-starting period in Chongqing on March 13, 2020. DETAILED DESCRIPTION

[0023] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0024] Example 1

[0025] (1) 185 representative rice varieties from each region were selected and named S1-S185 (including 113 japonica rice varieties and 72 indica rice varieties). They were planted in Fuyang, Hangzhou, Sanya, Hainan, and Shenyang, Liaoning. Their sowing dates were as follows:

[0026] Fuyang, Hangzhou (Hangzhou-0525): May 25, 2012, May 25, 2013, and May 25, 2017;

[0027] Sanya, Hainan (Sanya-1205): December 5, 2012, December 5, 2015, and December 5, 2017;

[0028] Shenyang, Liaoning (Shenyang-0420): April 20, 2016 and April 20, 2017.

[0029] (2) The heading dates (earing phenotypes) of different varieties at the three test sites over the years were integrated to obtain the average heading dates of different varieties at the three test sites. The results are shown in Table 1.

[0030] (3) The meteorological temperature and sunshine time of the three test sites from the 26th to the 70th day after sowing were integrated to obtain the average temperature T of the three test sites. n (℃), average sunshine time L n (h), the results are shown in Table 2.

[0031] (3) The average earing date of different varieties and different test points obtained in step (2); the average temperature T of different test points obtained in step (2) n (℃) and average sunshine time L n (h), substituted into the mathematical modeling formula, the corresponding light sensitivity index and temperature sensitivity index of 185 different rice varieties were calculated, and the results are shown in Table 1.

[0032] (4) The above 185 rice varieties were planted in Hangzhou (sowing date was June 25, 2019, referred to as Hangzhou-20190625) and Chongqing (sowing date was March 13, 2020, referred to as Chongqing-20200313), and the actual phenotypes at the heading stage (early heading stage) of the two places were investigated. The results are shown in Table 1; as well as the average temperature and average sunshine time from the 26th to the 70th day after sowing, the results are shown in Table 2.

[0033] (5) Based on the simulation formula, the initiation of earing of these 185 materials in Hangzhou and Chongqing was predicted. The predicted results were then compared and analyzed with the actual observation results in these two places. The results are shown in Figures 1 and 2, respectively.

[0034] Table 1: Phenotypes at the beginning of heading stage at each test site and light and temperature sensitivity indexes of each variety

[0035] Table 2: Average temperature and average sunshine time at each test site from 26th to 70th day after sowing

[0036] 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.

[0037] 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.

[0038] 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 quickly predicting the heading date of rice. It is characterized in that The steps include: (1) Determination of planting areas: Selecting areas at three 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 sites 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 points in step (1) on the 26th to 70th day after rice sowing for many years were integrated to obtain the average temperature T of the three test points on the 26th to 70th day after rice sowing. n (℃) and average sunshine time L n (h); (4) The average heading date H of the three test points in step (2) and step (3) is n , average temperature T n (℃) and average sunshine time L n (h), Substitute 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: H 1 =H 低纬 ,H 2 =H 中纬 ,H 3 =H 高纬 ,H 4 =H 待预测 ; H 2 =H 1 +H 2 ×PSI×(L 2 -L 1 ) / L 2 -H 2 ×TSI×(T 2 -T 1 ) / T 2 ; H 3 =H 1 +H 3 ×PSI×(L 3 -L 1 ) / L 3 -H 3 ×TSI×(T 3 -T 1 ) / T 3 ; H 4 =H 1 +H 4 ×PSI×(L 4 -L 1 ) / L 4 -H 4 ×TSI×(T 4 -T 1 ) / T 4 ; (5) Combining 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 heading date of rice according to claim 1, It is characterized in that The low-latitude region described 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 heading date of rice according to claim 1, It is characterized in that The initial heading stage in step (2) is when 10% of the main ears begin to emerge.

4. The method for rapidly predicting the heading date of rice according to claim 2, It is characterized in that 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; in Sanya, sowing was carried out on December 5, with a row spacing of 6 inches × 7 inches.

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