A method for promoting rapid tillering and heading of hydroponic rice based on red light and far-infrared light

Abstract

The present invention discloses a method for promoting rapid tillering and heading of hydroponic rice based on red light and far-infrared light. The method comprises performing light quality treatment on hydroponic rice in a light environment to enable rapid tillering and heading of the rice. The light environment adopts a red light to far-infrared light ratio of 0.60 and a light intensity of 800 μmol·m ‑2 ·s ‑1 The present invention adopts a hydroponic method, uses LED lamps with an appropriate ratio of red light to far-red light, accurately modulates the spectral wavelength and light intensity, and combines it with the nutrient solution of the required concentration for rice seedlings at different stages to promote early heading and flowering of rice, significantly shortening the growth cycle of rice seedlings and providing new ideas for accelerated rice breeding.

Description

Technical Field

[0001] The invention relates to a method for promoting rapid tillering and heading of hydroponic rice based on red light and far-infrared light, belonging to the technical field of rice planting. Background Art

[0002] Existing technologies primarily utilize varying ratios of red and blue mixed light to regulate the rice growth cycle, achieving accelerated rice breeding. However, this reduction in growth cycle duration is limited and falls far short of current scientific research and market demands. Far-red light (FR) plays a crucial role in regulating crop growth, development, heading, flowering, and fruit quality. By shifting the effective wavelength range of plant absorption from ultraviolet light (approximately 280 nm) to FR (700-750 nm), FR regulation can induce a shift between red- and far-red-absorbing configurations in phytochromes, thereby influencing crop morphology, physiology, and biochemistry, and regulating the crop's growth cycle. Currently, there are few technologies for FR regulation in crop breeding using LEDs, and LED breeding primarily focuses on substrate cultivation. Therefore, developing novel LED light quality and hydroponic cultivation methods could promote rapid heading and flowering in rice, enabling extended breeding generations while fully utilizing the nutrient solution to provide the rice seedlings with the nutrients they need at each stage, effectively preventing pests, diseases, weeds, and pesticide damage, and improving land utilization.

[0003] Existing patents, such as a rice cultivation method using LED plant lights in the absence of natural light (CN 105766506A), a method for rapid rice generation breeding (CN 114027120A), and a method for promoting rapid rice generation (CN116267470A), disclose regulating the rice growth period by controlling the quality of mixed red, white, and blue light. While this method effectively shortens the rice growth cycle, current methods for using mixed red, white, and blue light are numerous and often employ substrate cultivation, failing to meet research and development and market needs. Therefore, there is an urgent need to develop a method that combines alternative light quality parameters with hydroponic treatment to promote rapid rice heading and flowering, shorten the traditional breeding cycle, and provide technical support for ensuring food security. Summary of the Invention

[0004] In response to the problems existing in the above-mentioned prior art, the present invention provides a method for promoting rapid tillering and heading of hydroponic rice based on red light and far-infrared light. The method uses red light and far-infrared light to precisely modulate the spectral wavelength and light intensity, and combines it with the nutrient solution required by rice seedlings at different stages to achieve the purpose of promoting rapid tillering and heading of hydroponic rice.

[0005] In order to achieve the above-mentioned purpose, the present invention adopts a method for promoting rapid tillering and heading of hydroponic rice based on red light and far-infrared light, which performs light quality treatment on hydroponic rice under a light environment to enable the rice to quickly tiller and head;

[0006] The light environment used a red light to far-red light ratio of 0.60 and a light intensity of 800 μmol·m -2 ·s -1 .

[0007] Furthermore, the rice is Huajing No. 5.

[0008] Furthermore, the method further includes the following steps:

[0009] (1) Germination: After sterilizing the rice seeds, soak them in a dark environment, spread the seeds flat on a gauze mat, and germinate them until the rice seeds turn white.

[0010] (2) Seedling-seedling stage: Place the white rice seeds in alternate rows in the hydroponic box, and place the hydroponic box under the above light environment, with a red light to far-red light ratio of 0.60 and a light intensity of 800 μmol·m -2 ·s -1 Cultivate the rice until its root length reaches 5-6 cm, plant it in a hydroponic tank filled with nutrient solution 1, and cultivate it until the rice seedling stage. During the seedling-seedling stage, the day / night photoperiod is 22 hours / 2 hours, the day / night temperature is 30°C / 25°C, and the air humidity is 85%.

[0011] (3) Tillering-heading and flowering period: When the rice treated with the light environment in step (2) begins to tiller, add nutrient solution 2 to the hydroponic tank. At this time, the day / night photoperiod during the tillering period is regulated to 10 / 14 h, the day / night temperature is 33°C / 28°C, and the air humidity is 70%. When the rice begins to head and flower, the day / night temperature is regulated to 30°C / 25°C and the air humidity is 65%.

[0012] Furthermore, in step (1), the rice seeds are soaked in clean water at 30° C. in a dark environment.

[0013] Furthermore, in step (2), the whitened rice seeds are placed in alternate rows in a 96-well plate hydroponic box, and the hydroponic box is cultured with clean water.

[0014] Furthermore, the nutrient solution 1 in step (2) is obtained by diluting the nutrient solution mother solution 1 by 1000 times;

[0015] The nutrient solution mother solution 1 includes the following raw materials:

[0016] First component: 246.9 g / L Ca(NO3)2·4H2O, 161.5 g / L KNO3, 47.9 g / L NH4H2PO4, 144.8 g / L MgSO4·7H2O, 35.1 g / L (NH4)2SO4, 55.99 g / L EDTA-FeNa, 0.568 g / L Na2SiO3·9H2O;

[0017] Second component: 0.99 g / L MnCl2·7H2O, 1.86 g / L H3BO3, 1.24 g / L (NH4)6·MO7O 24 ·4H2O, 1.15 g / L ZnSO4, 0.518 g / L CuSO4.

[0018] Furthermore, the nutrient solution 2 in step (3) is obtained by diluting the nutrient solution mother solution 2 by 1000 times;

[0019] The nutrient solution mother solution 2 includes the following raw materials:

[0020] First component: 369.9g / L Ca(NO3)2·4H2O, 242.3g / L KNO3, 62.27g / L NH4H2PO4, 215.2g / L MgSO4·7H2O, 50.68g / L (NH4)2SO4, 55.99g / L EDTA-FeNa, 0.901g / L Na2SiO3·9H2O;

[0021] Second component: 0.99 g / L MnCl2·7H2O, 1.86 g / L H3BO3, 1.24 g / L (NH4)6·MO7O 24 ·4H2O, 1.15 g / L ZnSO4, 0.518 g / L CuSO4.

[0022] Furthermore, during the tillering-heading and flowering period of step (3), the nutrient solution three is sprayed on the rice leaves every 7 days, and the nutrient solution three is obtained by diluting the nutrient solution mother solution three 1000 times;

[0023] The nutrient solution mother solution three includes the following raw materials:

[0024] The first component: 1.5 g / L CH4N2O, 1 g / L Ca(H2PO4)2·H2O, 1.5 g / L KH2PO4;

[0025] Second component: 0.05 g / L MnCl2·7H2O, 0.1 g / L H3BO3, 0.05 g / L (NH4)6·MO7O 24·4H2O, 0.2 g / L ZnSO4, 0.05 g / L CuSO4.

[0026] Furthermore, the hydroponic tanks in step (2) and step (3) both use a circulating water tank, and the circulating water tank circulates the nutrient solution according to a procedure of 2 hours of circulation and 1 hour of rest.

[0027] Principle of the Invention: This invention is based on far-red light (FR). By regulating FR, the invention can induce the conversion of phytochrome between red-light absorbing and far-red-light absorbing configurations, thereby affecting crop morphology, physiology, and biochemistry, and regulating crop growth cycles. Furthermore, to ensure uniform light quality, the cultivation racks were completely shaded on all sides. The height of the LED lights was controlled at 1 m, and light intensity was measured using a spectroradiometer (PS-300, Apogee Instruments Inc., Logan, UT, USA). The target light intensity was allowed to vary within a range of no more than 20 μmol·m -2 ·s -1 .

[0028] Compared with the existing technology, the present invention adopts a hydroponic method, uses LED lamps with an appropriate red light to far-red light ratio, accurately modulates the spectral wavelength and light intensity, and combines it with the nutrient solution of the required concentration for rice seedlings at different stages, thereby promoting the early heading and flowering of rice, significantly shortening the growth cycle of rice seedlings, and providing new ideas for accelerated rice breeding. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the embodiments of the present application 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 only some embodiments of the present application. For those skilled in the art, other drawings can be obtained based on these drawings without paying any creative work.

[0030] Figure 1 This is a light processing spectrum distribution diagram of Example 1 of the present invention; in the figure, the ratio of red light to far-red light (R / FR) is 0.60;

[0031] Figure 2 In Example 1 of the present invention, the expression levels of key genes for rice flowering were affected by six different light treatments to screen out suitable light environment parameters for promoting rice heading and flowering. In the figure, T1 is the full spectrum, T2 is R:B=1:3, T3 is R:B=1:3, T4 is the red light to far-red light ratio (R / FR)=0.60, T5 is R / FR=3.0, and T6 is R / FR=6.7.

[0032] Figure 3The phenotypes of rice under suitable light treatment for 7 days and 43 days were screened for Example 1 of the present invention; in the figure, T1 is the full spectrum, T2 is R / FR=6.7, T3 is R / FR=0.60, and T4 is R / FR=3.0; Figures A and B respectively represent the phenotypes of rice under light treatment for 7 days and 43 days;

[0033] Figure 4 The rice grain phenotype under suitable light treatment was screened for Example 1 of the present invention; in the figure, T1 is the full spectrum, T2 is R / FR=6.7, T3 is R / FR=0.60, and T4 is R / FR=3.0; Figures A and B respectively represent the rice panicle length and grain set phenotypes under light treatment. DETAILED DESCRIPTION

[0034] The following embodiments are further descriptions of the present invention to illustrate the technical content of the present invention, but the essential content of the present invention is not limited to the following embodiments. Ordinary technicians in this field can and should know that any simple changes or replacements based on the essential spirit of the present invention should fall within the scope of protection required by the present invention.

[0035] In the description of the present invention, it should be understood that the ratio of R to FR is calculated using the formula R / FR = the sum of photon flux density from (655-665 nm) / (725-735 nm).

[0036] Example 1

[0037] A method for promoting rapid tillering and heading of hydroponic rice based on red light and far-infrared light was developed. The japonica rice variety "Huajing 5" was used as the research material. The hydroponic method was used. The red light to far-infrared light ratio was 0.60 and the light intensity was 800 μmol·m -2 ·s -1 Under the light environment of , the light quality of hydroponic rice was treated;

[0038] To ensure that the grafted seedlings grow in a suitable light environment and uniform light quality, the cultivation racks were completely shaded on all sides. The height of the LED lights was controlled at 1 m, and the light intensity was measured using a spectroradiometer (PS-300, Apogee Instruments Inc., Logan, UT, USA) to measure the spectral distribution ( Figure 1 );

[0039] The specific steps include:

[0040] (1) Dark soaking and germination: After disinfection, select "Huajing No. 5" rice seeds and soak them in clean water at 30℃ in the dark for 5 hours. After soaking, spread the seeds with gauze as a cushion and keep them moist. Then continue germination for 24 hours until the rice seeds turn white.

[0041] (2) Seedling-seedling stage: Place high-quality white rice seeds in alternate rows in a 96-well plate hydroponic box, and place the hydroponic box in an environment with a red light to far-red light ratio (R / FR) of 0.60 and a light intensity of 800 μmol·m -2 ·s -1 Cultivate in clear water for 2 days under LED light. When the rice root system reaches 5-6 cm in length, use planting baskets and planting cotton to plant the rice in a hydroponic tank (with a circulation function, such as a circulating water tank) using liquid nutrient solution 1 (pH = 5.5-6.0, EC = 1.5-1.8). Cultivate for about 6-7 days, and the rice seedling stage ends and the early tillering stage begins. During the seedling-seedling stage, the facility environmental parameters are controlled as follows: a 22 / 2 h day / night photoperiod, a day / night temperature of 30°C / 25°C, and an air humidity of 85%.

[0042] Among them, the preparation and use of the mother solution of nutrient solution 1:

[0043] Dissolve Ca(NO3)2·4H2O 246.9g, KNO3 161.5g, NH4H2PO4 47.9g, MgSO4·7H2O 144.8g, (NH4)2SO4 35.1g, EDTA-FeNa 55.99g, Na2SiO3·9H2O 0.568g (macroelements); MnCl2·7H2O 0.99g, H3BO3 1.86g, (NH4)6·MO7O 24 4H2O 1.24g, ZnSO4 1.15g, CuSO4 0.518g (trace elements).

[0044] Before use, dilute the mother liquor of nutrient solution 1 1000 times, stir it thoroughly and inject it into the circulating water tank at the bottom of the cultivation rack. Open the circulating water tank and circulate it according to the program of 2 hours per cycle and 1 hour of rest.

[0045] (3) Tillering-heading and flowering period: During the tillering-heading and flowering period of rice, the R / FR ratio was 0.60 and the light intensity was 800 μmol·m -2 ·s -1 Cultivation was carried out under an LED light environment, with a 10 / 14 h day / night photoperiod. The day / night temperature during the tillering stage was 33°C / 28°C, and the air humidity was 70%. The day / night temperature during the heading and flowering stage was 30°C / 25°C, and the air humidity was 65%. Rice was planted in hydroponic tanks on cultivation racks and cultivated with liquid nutrient solution II (pH 5.5-6.0, EC 2.5-3.0). To promote tillering and heading, nutrient solution III was sprayed on the rice leaves every 7 days. The tillering, heading, and flowering stages of rice were completed after about 38-43 days of cultivation.

[0046] Among them, the preparation and use of the mother solution of nutrient solution 2 during the tillering-heading and flowering period:

[0047] Dissolve Ca(NO3)2·4H2O 369.9g, KNO3 242.3g, NH4H2PO4 62.27g, MgSO4·7H2O 215.2g, (NH4)2SO4 50.68g, EDTA-FeNa 55.99g, Na2SiO3·9H2O 0.901g (macroelements); MnCl2·7H2O 0.99g, H3BO3 1.86g, (NH4)6·MO7O 24 4H2O 1.24g, ZnSO4 1.15g, CuSO4 0.518g (trace elements);

[0048] The method of diluting the mother solution of nutrient solution 2 and using the nutrient solution in the water tank is the same as the above step (2).

[0049] Preparation and use of mother solution for foliar spraying of nutrient solution 3:

[0050] Dissolve CH4N2O 1.5g, Ca(H2PO4)2·H2O 1g, KH2PO41.5g (macroelements); MnCl2·7H2O 0.05g, H3BO30.1g, (NH4)6·MO7O in 1L of water. 24 4H2O 0.05g, ZnSO4 0.2g, CuSO4 0.05g (trace elements).

[0051] Dilute the mother solution of nutrient solution 3 1000 times, stir and dissolve it thoroughly, and then spray it evenly on rice leaves with a spray bottle every 7 days.

[0052] Depend on Figure 2 It can be seen that treating rice with red light and far-red light at an appropriate ratio can promote the expression levels of key genes involved in rice flowering. qPCR analysis of genes reported to be involved in controlling rice heading and flowering found that adding far-red light can promote the expression levels of genes related to rice heading and flowering. Compared with other light treatments, T4 treatment can significantly promote the expression levels of genes related to rice heading and flowering, such as Hd1, EHd1, Hd3a, and RFT1. In short, supplementing far-red light and controlling the red light / far-red light ratio can increase the expression levels of genes related to rice heading and flowering, promote rice heading and flowering, and shorten the reproductive cycle.

[0053] From Table 1 and Figure 3 It can be seen that after 7 days of light treatment ( Figure 3 A) and 43 days ( Figure 3Observations of the rice phenotypes (Figure 2B) revealed that adding far-red light promoted early tillering (7 days) in all rice varieties. The T3 treatment significantly promoted tillering and improved seedling growth at 7 days. At 43 days, the T3 treatment significantly accelerated heading and flowering compared to the other light treatments. Furthermore, the germination-heading-flowering period for "Huajing No. 5" under natural conditions is 88 days. However, adding far-red light, which reduces the red light to far-red light ratio, shortened the germination-heading-flowering period by 45 days to 43 days.

[0054] Depend on Figure 4 It can be seen that by observing the rice grain phenotype under light treatment, it was found that adding far-infrared light can promote the elongation of rice panicle length ( Figure 4 A), and will not affect the fruiting of rice grains ( Figure 4 B).

[0055] Therefore, the present invention adopts far-infrared light and nutrient solution in combination, which can significantly and quickly promote the tillering and heading effect of rice.

[0056] Table 1 The growth cycle of rice from germination to heading and flowering under different methods

[0057]

[0058] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions or improvements made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A method for promoting rapid tillering and heading of hydroponic rice based on red light and far-infrared light, characterized in that: Treating the hydroponic rice with light quality under the light environment can make the rice tiller and ear quickly; The light environment used a red light to far-red light ratio of 0.60 and a light intensity of 800 μmol·m -2 ·s -1 ; The following steps are involved: (1) Germination: After sterilizing the rice seeds, soak them in a dark environment, spread the seeds flat on a gauze mat, and germinate them until the rice seeds turn white. (2) Seedling-seedling stage: Place the white rice seeds in alternate rows in the hydroponic box, and place the hydroponic box under the above light environment, with a red light to far-red light ratio of 0.60 and a light intensity of 800 μmol·m -2 ·s -1 Cultivate the rice until its root length reaches 5-6 cm, plant it in a hydroponic tank filled with nutrient solution 1, and cultivate it until the rice seedling stage. During the seedling-seedling stage, the day / night photoperiod is 22 hours / 2 hours, the day / night temperature is 30°C / 25°C, and the air humidity is 85%. The nutrient solution 1 is obtained by diluting the nutrient solution mother solution 1 by 1000 times; the nutrient solution mother solution 1 comprises the following raw materials: a first component: 246.9 g / L Ca(NO3)2·4H2O, 161.5 g / L KNO3, 47.9 g / L NH4H2PO4, 144.8 g / LMgSO4·7H2O, 35.1 g / L (NH4)2SO4, 55.99 g / L EDTA-FeNa, and 0.568 g / L Na2SiO3·9H2O; a second component: 0.99 g / L MnCl2·7H2O, 1.86 g / L H3BO3, and 1.24 g / L (NH4)6·MO7O 24 ·4H2O, 1.15 g / LZnSO4, 0.518 g / L CuSO4; (3) Tillering-heading and flowering period: When the rice treated with the light environment in step (2) begins to tiller, add nutrient solution 2 to the hydroponic tank. At this time, the day / night photoperiod during the tillering period is regulated to 10 / 14 h, the day / night temperature is 33°C / 28°C, and the air humidity is 70%. When the rice begins to head and flower, the day / night temperature is regulated to 30°C / 25°C and the air humidity is 65%. The nutrient solution II is obtained by diluting the nutrient solution mother solution II by 1000 times; the nutrient solution mother solution II comprises the following raw materials: a first component: 369.9 g / L Ca(NO3)2·4H2O, 242.3 g / L KNO3, 62.27 g / L NH4H2PO4, 215.2 g / LMgSO4·7H2O, 50.68 g / L (NH4)2SO4, 55.99 g / L EDTA-FeNa, and 0.901 g / L Na2SiO3·9H2O; a second component: 0.99 g / L MnCl2·7H2O, 1.86 g / L H3BO3, and 1.24 g / L (NH4)6·MO7O 24 ·4H2O, 1.15 g / LZnSO4, 0.518 g / L CuSO4; During the tillering-heading and flowering stages, nutrient solution III was sprayed on the rice leaves every 7 days. The nutrient solution III was obtained by diluting nutrient solution mother solution III 1000 times. The nutrient solution mother solution III included the following raw materials: first component: 1.5 g / L CH4N2O, 1 g / L Ca(H2PO4)2·H2O, 1.5 g / L KH2PO4; second component: 0.05 g / L MnCl2·7H2O, 0.1 g / L H3BO3, 0.05 g / L (NH4)6·MO7O 24 ·4H2O, 0.2 g / L ZnSO4, 0.05 g / L CuSO4.

2. The method for promoting rapid tillering and heading of hydroponic rice based on red light and far-infrared light according to claim 1, characterized in that: The rice is Huajing No.

5.

3. The method for promoting rapid tillering and heading of hydroponic rice based on red light and far-infrared light according to claim 1, characterized in that: In the step (1), the rice seeds are soaked in clean water at 30° C. in a dark environment.

4. The method for promoting rapid tillering and heading of hydroponic rice based on red light and far-infrared light according to claim 1, characterized in that: In the step (2), the whitened rice seeds are placed in alternate rows in a 96-well plate hydroponic box, and the hydroponic box is cultured with clean water.

5. The method for promoting rapid tillering and heading of hydroponic rice based on red light and far-infrared light according to claim 1, characterized in that: The hydroponic tanks in step (2) and step (3) both use a circulating water tank, and the circulating water tank circulates the nutrient solution according to a procedure of 2 hours of circulation and 1 hour of rest.

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