A breeding method to increase rice yield

Abstract

This invention belongs to the field of rice breeding technology, and in particular to a breeding method for improving rice yield. The method includes: Step 1, Experimental Selection: Three types of indica cytoplasmic japonica rice were selected: Shennong 265, Shennong 9741, and Shennong 9816. Three portions of each of these japonica rice varieties were prepared. Twelve portions of Longdao 18 were also selected. Step 2, Experimental Design: Three experimental fields were planted with Longdao 18 and marked as Group 1 as a control. Using Shennong 265, Shennong 9741, and Shennong 9816 as the female parent and Longdao 18 as the male parent, a breeding method involving three generations of backcrossing followed by seven generations of self-pollination was employed. Compared with the control parent, the rice yield was increased, and plant height and panicle number showed significant differences. All agronomic traits were higher than those of the parent Longdao 18 (japonica quality and japonica kernel), with significant differences in plant height and thousand-grain weight. This indicates that under the same nuclear genetic background, indica cytoplasmic type has a promoting effect on yield improvement.

Description

Technical Field

[0001] This invention belongs to the field of rice breeding technology, specifically relating to a breeding method for increasing rice yield. Background Technology

[0002] Northeast my country is the main production area of ​​japonica rice. With the application of ideal plant type and the theory of hybrid vigor between indica and japonica rice, superior varieties bred directly or indirectly through indica-japonica hybridization have made a significant contribution to increasing my country's grain output. However, due to the narrow genetic lineage of cold-region japonica rice, the yield increase is relatively small. Therefore, increasing rice yield is a goal for breeders, necessitating a breeding method to improve rice yield. Summary of the Invention

[0003] To address the problems mentioned in the background section, this invention provides a breeding method for increasing rice yield, which has the characteristic of increasing rice production.

[0004] To achieve the above objectives, the present invention provides the following technical solution: a breeding method for increasing rice yield, comprising the following steps:

[0005] Step 1: Experimental selection: Select three types of indica cytoplasmic japonica rice, namely Shennong 265, Shennong 9741 and Shennong 9816. Prepare three portions of each of these japonica rice varieties, and then select twelve portions of Longdao 18.

[0006] Step 2, Experimental Design: Three experimental fields were selected, all planted with Longdao 18 and marked as Group 1, serving as the control. Three experimental fields were selected, all planted with a hybrid of Shennong 265 and Longdao 18 and marked as Group 2. Three experimental fields were selected, all planted with a hybrid of Shennong 9741 and Longdao 18 and marked as Group 3. Three experimental fields were selected, all planted with a hybrid of Shennong 9816 and Longdao 18 and marked as Group 4. The breeding methods for Groups 2, 3, and 4 all involved three generations of continuous backcrossing followed by seven generations of self-crossing. The construction method is described in [link to documentation]. Figure 5 See phenotype Figure 6 .

[0007] Step 3: Determination of agronomic traits of japonica rice: After rice harvest, relevant data such as panicle length, number of filled grains, number of empty grains, number of ears, and thousand-grain weight were recorded. Then, the rice grains were harvested at maturity and stored indoors for 3 months. The rice was processed using a Dazhu FC2K rice huller to determine the brown rice rate. After processing with a Kett rice milling machine, the rice was weighed to determine the milled rice rate. The head rice rate and appearance quality (chalky grain rate and chalkiness) were determined using a Wanshen SC-E rice quality analyzer. The cooking and eating quality (amylose content, protein content, and eating value) and nutritional quality (protein content) were determined using a Satake RC-TA11A rice grain taste meter.

[0008] Preferably, the planting method in step two is to plant 10 rows with a row spacing of 30cm × 13.3cm, with one seedling per hole and 45 holes per row.

[0009] Preferably, the fertilization method in step two is to apply 135 kg·hm⁻² of pure nitrogen, with a base fertilizer: tillering fertilizer: panicle fertilizer ratio of 5:4:1, 70 kg·hm⁻² of K₂O, 70 kg·hm⁻² of P₂O₅, and apply phosphate fertilizer as base fertilizer in one application, and apply potassium fertilizer at a ratio of base fertilizer: panicle fertilizer of 1:1.

[0010] Preferably, the determination method in step three specifically involves synthesizing two indica-japonica specific chloroplast primers, P1 (5'-TTGTATTTCCTTAGACTT-3') and P2 (5'-ATCTATGGGGTCACAGCC-3'), with the primer name cpDNA69.

[0011] Preferably, after DNA extraction in step three, the DNA is detected by agarose gel electrophoresis. The PCR reaction system is as follows: the total PCR amplification volume is 20 μL, including 2 μL of DNA template, 2 μL of buffer (MgCl2 2.0 mmol•L -1), 1 μL of each primer, 1 μL of dNTP, and 0.5 μL of Taq DNA polymerase. Any remaining amount is supplemented with ddH2O. The product is amplified using the amplification program.

[0012] Preferably, the amplification program is as follows: pre-denaturation at 94 ℃ for 4 min, followed by 94 ℃ for 0.5 min, 55 ℃ for 40 s, 72 ℃ for 1 min, for 40 cycles; and finally extension at 72 ℃ for 7 min. The amplification products are detected by 3% agarose gel electrophoresis and finally by ultraviolet gel imaging.

[0013] Preferably, in step one, the band patterns of Shennong 265, Shennong 9741, and Shennong 9816 are consistent with the band pattern of typical indica rice 9311, while the bands of typical japonica rice Nipponbare lag behind the indica type cpDNA, indicating that the chloroplasts of these three conventionally cultivated japonica rice varieties are of the indica type (see...). Figure 4 ).

[0014] Compared with the prior art, the beneficial effects of the present invention are:

[0015] 1. This invention utilizes Shennong 265, Shennong 9741, and Shennong 9816 as female parents and Longdao 18 as male parent. Through a breeding method of three generations of backcrossing followed by seven generations of self-pollination, the rice yield is increased compared to the control parent. The plant height and panicle number show significant differences, and all agronomic traits are higher than those of the parent Longdao 18 (japonica quality and japonica kernel). The plant height and thousand-grain weight show significant differences, indicating that under the same nuclear genetic background, indica-type cytoplasm has a promoting effect on yield improvement. Attached Figure Description

[0016] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used in conjunction with embodiments of the invention to explain the invention and do not constitute a limitation thereof. In the drawings:

[0017] Figure 1 This is a schematic diagram of the cultivation method of the present invention;

[0018] Figure 2 This is a schematic diagram illustrating the production output of the present invention;

[0019] Figure 3 This is a schematic diagram of rice quality according to the present invention;

[0020] Figure 4 This is a schematic diagram of the PCR detection results of chloroplast DNA according to the present invention;

[0021] Figure 5 This is a schematic diagram illustrating the construction method of the indica japonica core material such as Shennong 265 of the present invention;

[0022] Figure 6 This is a schematic diagram of the phenotype of the isonuclear heterogeneous material of the present invention. Detailed Implementation

[0023] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0024] Example 1

[0025] Please see Figure 1-6 The present invention provides the following technical solution: a breeding method for increasing rice yield, comprising the following steps:

[0026] Step 1: Experimental selection: Three types of indica cytoplasmic japonica rice, namely Shennong 265, Shennong 9741 and Shennong 9816, were selected as female parents. Three portions of each of the above japonica rice were prepared, and twelve portions of Longdao 18 were selected as male parents.

[0027] Step 2, Experimental Design: Three experimental fields were selected, all planted with Longdao 18 and marked as Group 1, as a control. Three experimental fields were selected, all planted with a hybrid variety of Shennong 265 and Longdao 18 and marked as Group 2. Three experimental fields were selected, all planted with a hybrid variety of Shennong 9741 and Longdao 18 and marked as Group 3. Three experimental fields were selected, all planted with a hybrid variety of Shennong 9816 and Longdao 18 and marked as Group 4. The breeding method for Groups 2, 3 and 4 was to continuously backcross for 3 generations and then selfcross for 7 generations.

[0028] Step 3: Agronomic Trait Determination of Japonica Rice: After rice harvest, relevant data such as panicle length, number of filled grains, number of empty grains, number of ears, and thousand-grain weight were recorded. Then, the rice grains were harvested at maturity and stored indoors for 3 months. The rice was processed using a Dazhu FC2K rice huller to determine the brown rice rate. After processing with a Kett rice milling machine, the rice was weighed to determine the milled rice rate. The head rice rate and appearance quality (chalky grain rate and chalkiness) were determined using a Wanshen SC-E rice quality analyzer. The cooking and eating quality (amylose content, protein content, and eating value) and nutritional quality (protein content) were determined using a Satake RC-TA11A rice grain taste meter.

[0029] Specifically, the planting method in step two is to plant 10 rows with a row spacing of 30cm × 13.3cm, with one seedling per hole, and 45 holes per row.

[0030] Specifically, the fertilization method in step two is to apply 135 kg·hm⁻² of pure nitrogen, with a base fertilizer: tillering fertilizer: panicle fertilizer ratio of 5:4:1, 70 kg·hm⁻² of K₂O, 70 kg·hm⁻² of P₂O₅, and apply phosphate fertilizer as a base fertilizer in one application. Potassium fertilizer is applied at a ratio of base fertilizer: panicle fertilizer of 1:1.

[0031] Specifically, the determination method in step three involves synthesizing two indica- and japonica-specific chloroplast primers: P1 (5'-TTGTATTTCCTTAGACTT-3') and P2 (5'-ATCTATGGGGTCACAGCC-3'), with the primer name cpDNA69.

[0032] Specifically, after extracting DNA using the method described in step three, the DNA is detected by agarose gel electrophoresis. The PCR reaction system is as follows: the total PCR amplification volume is 20 μL, including 2 μL of DNA template, 2 μL of buffer (MgCl2 2.0 mmol•L -1), 1 μL of each primer, 1 μL of dNTP, and 0.5 μL of Taq DNA polymerase. Any remaining amount is supplemented with ddH2O. The products are amplified using the amplification program.

[0033] Specifically, the amplification program was as follows: pre-denaturation at 94 ℃ for 4 min, followed by 94 ℃ for 0.5 min, 55 ℃ for 40 s, and 72 ℃ for 1 min, for 40 cycles; finally, extension at 72 ℃ for 7 min. The amplification products were detected by 3% agarose gel electrophoresis and finally by UV gel imaging.

[0034] Specifically, in step one, the banding patterns of Shennong 265, Shennong 9741, and Shennong 9816 are consistent with the banding pattern of typical indica rice 9311, indicating that the chloroplasts of these three conventionally cultivated japonica rice varieties are of the indica type.

[0035] Finally, it should be noted that the above descriptions are merely preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A breeding method for increasing rice yield, characterized in that: Includes the following steps: Step 1: Experimental selection: Three types of indica cytoplasmic japonica rice, namely Shennong 265, Shennong 9741 and Shennong 9816, were selected as female parents. Three portions of each of the above japonica rice were prepared, and twelve portions of Longdao 18 were selected as male parents. Step 2, Experimental Design: Three experimental fields were selected, all planted with Longdao 18 and marked as Group 1, as a control. Three experimental fields were selected, all planted with a hybrid variety of Shennong 265 and Longdao 18 and marked as Group 2. Three experimental fields were selected, all planted with a hybrid variety of Shennong 9741 and Longdao 18 and marked as Group 3. Three experimental fields were selected, all planted with a hybrid variety of Shennong 9816 and Longdao 18 and marked as Group 4. The breeding methods for Groups 2, 3 and 4 were all based on three consecutive backcrosses followed by seven self-crosses. Step 3: Rice Quality Determination: After rice harvest, data on panicle length, number of filled grains, number of empty grains, number of ears, and thousand-grain weight were recorded. The mature rice grains were then stored indoors for 3 months. The rice was processed using a Daitake FC2K rice milling machine to determine the brown rice rate. After processing with a Kett rice milling machine, the rice was weighed to determine the polished rice rate. The head rice rate and appearance quality were determined using a Wanshen SC-E rice quality analyzer. Cooking, eating, and nutritional quality were determined using a Satake RC-TA11A rice grain taste meter. The specific determination method in step three involves synthesizing two indica-japonica specific chloroplast primers, P1 and P2. P1 is 5'-TTGTATTTCCTTAGACTT-3', and P2 is 5'-ATCTATGGGGTCACAGCC-3'. The primer name is cpDNA69. In step one, the banding patterns of Shennong 265, Shennong 9741, and Shennong 9816 are consistent with the banding pattern of typical indica rice 9311, indicating that the chloroplasts of these three conventionally cultivated japonica rice varieties are of the indica type.

2. The breeding method for increasing rice yield according to claim 1, characterized in that: The planting method in step two is to plant 5 rows with a row spacing of 30cm × 13.3cm, with one seedling per hole and 10 holes per row.

3. The breeding method for increasing rice yield according to claim 1, characterized in that: The fertilization method in step two is to apply 135 kg·hm⁻² of pure nitrogen, with a base fertilizer: tillering fertilizer: panicle fertilizer ratio of 5:4:1, 70 kg·hm⁻² of phosphorus fertilizer as a base fertilizer applied once, and potassium fertilizer applied at a base fertilizer: panicle fertilizer ratio of 1:

1.

4. The breeding method for increasing rice yield according to claim 1, characterized in that: After DNA extraction in step three, the DNA is detected by agarose gel electrophoresis. The PCR reaction system is as follows: the total PCR amplification volume is 20 uL, including 2 uL of DNA template, 2 uL of buffer (MgCl2 20 Mm), 1 uL of each primer, 1 uL of dNTP, 0.5 uL of Taq DNA polymerase, and any insufficient part is supplemented with ddH2O. The product is amplified using the amplification program.

5. The breeding method for increasing rice yield according to claim 4, characterized in that: The amplification program was as follows: pre-denaturation at 94 °C for 4 min, followed by 94 °C for 0.5 min, 55 °C for 40 s, 72 °C for 1 min, for 40 cycles; and finally extension at 72 °C for 7 min. The amplification products were detected by 3% agarose gel electrophoresis and finally by ultraviolet gel imaging.

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