A method for breeding new large-ear wheat varieties

Abstract

The invention discloses a method for breeding a new variety of large-spike wheat, comprising the following steps: S1: selecting wheat seeds with full grains, uniform color and gloss as male and female parents; S2: marking molecules related to multi-spike traits and large-spike traits, and designing specific primers; S3: constructing a map of genetic background using the developed molecular markers; S4: selecting wheat seeds with different marker types as parents for hybridization; S5: screening individuals with different phenotypes from hybrid offspring to establish a segregating population; S6: performing molecular marker analysis on the segregating population, selecting individuals carrying the target gene, and self-pollinating them; S7: performing phenotype verification on the individuals selected by MAS, and performing continuous self-pollination to obtain a new variety. The advantages of the present invention over the existing technology are that the present invention can quickly analyze a large number of samples, greatly improve the efficiency of breeding, and accurately identify and select individuals with specific traits.

Description

Technical Field

[0001] The invention relates to the technical field of wheat breeding, and in particular to a breeding method for a new large-spike wheat variety. Background Art

[0002] Wheat is one of the most important food crops in the world. Its yield and quality are of great significance to human survival and development. Some tall-stalked wheat varieties have an excellent shape of multiple ears, but the wheat grains in the multiple-ear wheat are not full enough. It is necessary to increase the grains of the wheat ears on the basis of the multiple ears and cultivate new wheat varieties with multiple and large ears.

[0003] In the usual process of breeding new wheat varieties with multiple ears and large spikes, it is necessary to screen out excellent individual plants from the first-generation hybrid of the parents, self-pollinate the individual plants, screen out excellent individual plants, and continue to self-pollinate to finally obtain stable new wheat varieties with multiple ears and large spikes. However, the traditional screening method is based on phenotypic observation. The phenotype is greatly affected by the environment and may perform differently in different environments, resulting in unstable screening results. Secondly, the phenotype is the result of the interaction between the genotype and the environment and may not accurately reflect the genetic characteristics of the individual. Thirdly, the screening cycle is long and it takes many generations of self-pollination and observation to fix the excellent traits. Summary of the invention

[0004] The technical problem to be solved by the present invention is to overcome the above technical defects and provide a method for breeding new varieties of large-spike wheat by using molecular marker technology to assist in selecting and tracking target traits and improve breeding efficiency.

[0005] In order to solve the above problems, the technical solution of the present invention is: a method for breeding new varieties of large-eared wheat, comprising the following steps:

[0006] S1: Select Zhengmai 7698 and Chuanmai 93 wheat seeds with full grains, uniform color and glossy texture as male and female parents;

[0007] S2: Mark the molecules related to the multiple-ear traits of Zhengmai 7698 and the large-ear traits of Chuanmai 93, and design specific primers;

[0008] S3: Using the developed molecular markers, the genetic background of Zhengmai 7698 with multiple spikes and Chuanmai 93 with large spikes were mapped to determine the positional relationship between the markers and the target gene;

[0009] S4: Select wheat seeds of Zhengmai 7698 with multiple spikes and Chuanmai 93 with large spikes of different marker types as parents for hybridization;

[0010] S5: Screen out individuals with different phenotypes from the hybrid offspring and establish segregating populations;

[0011] S6: Perform molecular marker analysis on the segregating population, select individuals carrying the target gene, and make them self-fertilize;

[0012] S7: Phenotypic verification of individuals selected by MAS is performed, and continuous self-pollination is performed to obtain new improved wheat varieties with multiple and large spikes.

[0013] Furthermore, in the step S2, fresh leaves need to be collected from Zhengmai 7698 with many ears and Chuanmai 93 with large ears, total DNA is extracted using a DNA extraction kit according to the instructions, specific primers are designed according to known gene sequences using primer design software, the DNA samples are amplified using a PCR instrument, the amplification conditions include pre-denaturation, denaturation, annealing and extension steps, the amplified DNA samples are separated by an electrophoresis instrument, the electrophoresis results are observed and recorded using a gel imaging system, and the polymorphic markers are determined.

[0014] Furthermore, in step S3, the molecular marker products amplified by PCR need to be sequenced or genotyped using a molecular marker analysis system. The obtained genotype data are compared with the known genetic map through data analysis software to determine the position of each marker on the chromosome. This process may require the integration and analysis of multiple markers to construct a complete genetic map. After the map is constructed, the linkage relationship between the marker and the target trait is analyzed to provide a basis for subsequent MAS.

[0015] Furthermore, in the step S4, it is necessary to select healthy multi-spike Zhengmai 7698 and large-spike Chuanmai 93 wheat plants as parents before the wheat blooms, among which the multi-spike Zhengmai 7698 is used as the female parent and the large-spike Chuanmai 93 wheat is used as the male parent. During the flowering period of the female plant, anthers are removed using a emasculating needle to prevent self-pollination. Then, the emasculated flowers are sealed with bags. After the pollen matures, pollen is collected from the male plant and smeared on the stigma of the female plant to complete artificial hybridization. After hybridization, the flowers are bagged again to prevent contamination by other pollen, and the hybrid combination is marked for subsequent tracking.

[0016] Furthermore, in the step S5, the hybridized seeds need to be sown, cultivated to maturity, and the phenotypic characteristics of each plant, such as ear type, number of ears, etc., are observed and recorded, and individuals with multiple ears and large ears are screened out based on the phenotypic characteristics.

[0017] Furthermore, in the step S6, fresh leaves need to be collected from each plant of the separated group, DNA needs to be extracted using a DNA extraction kit, the DNA samples are amplified by a PCR instrument using previously designed specific primers, the amplified DNA samples are separated by an electrophoresis instrument, the electrophoresis results are observed using a gel imaging system, the genotype of each individual is determined based on the band pattern, and individuals carrying the target gene are selected for subsequent self-pollination or reproduction to fix the target trait.

[0018] Furthermore, in step S7, the individuals selected by MAS need to be planted in the field and subjected to conventional agricultural management. During the entire growth cycle, the phenotypic characteristics of the plants, such as growth habits, disease resistance, and yield, are observed and recorded. Through comparative experiments, the effect of molecular marker-assisted selection is verified, and individuals with excellent performance are continuously self-pollinated to fix the excellent traits. Through multiple generations of selection and self-pollination, a new variety with multiple and large ears of stable panicles is finally bred.

[0019] The advantages of the present invention over the prior art are as follows: a method for breeding new large-spike wheat varieties of the present invention uses molecular marker technology to assist in selecting and tracking target traits. The molecular marker technology can analyze a large number of samples in a short period of time, greatly improving the efficiency of breeding; the molecular markers are directly related to the genotype of the plant, so individuals with specific traits can be very accurately identified and selected; compared with traditional phenotypic selection, the molecular markers are not affected by environmental factors and can be detected at any growth stage. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 The present invention is a schematic diagram of the process of a method for breeding a new large-ear wheat variety. DETAILED DESCRIPTION

[0021] Exemplary embodiments will be described in detail herein, examples of which are shown in the accompanying drawings. When the following description refers to the drawings, the same numbers in different drawings represent the same or similar elements unless otherwise indicated. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present disclosure. Instead, they are merely examples of devices consistent with some aspects of the present disclosure as detailed in the appended claims.

[0022] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the accompanying drawings in the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0023] Embodiment 1:

[0024] like Figure 1As shown, a method for breeding new varieties of large-eared wheat is characterized by comprising the following steps:

[0025] S1: Select Zhengmai 7698 and Chuanmai 93 wheat seeds with full grains, uniform color and glossy texture as male and female parents;

[0026] S2: Mark the molecules related to the multiple-ear trait of Zhengmai 7698 and the large-ear trait of Chuanmai 93, and design specific primers; collect fresh leaves from the multiple-ear Zhengmai 7698 and the large-ear Chuanmai 93; use a DNA extraction kit to extract total DNA according to the instructions; use primer design software to design specific primers based on known gene sequences; amplify the DNA samples using a PCR instrument; the amplification conditions include pre-denaturation, denaturation, annealing and extension steps; the amplified DNA samples are separated by an electrophoresis instrument; the electrophoresis results are observed and recorded using a gel imaging system to determine the polymorphic markers.

[0027] S3: Using the developed molecular markers, a genetic background map of the multi-spike Zhengmai 7698 and the large-spike Chuanmai 93 is constructed to determine the positional relationship between the marker and the target gene. The molecular marker products amplified by PCR are sequenced or genotyped using a molecular marker analysis system. The obtained genotype data is compared with the known genetic map through data analysis software to determine the position of each marker on the chromosome. This process may require the integration and analysis of multiple markers to construct a complete genetic map. After the map is constructed, the linkage relationship between the marker and the target trait is analyzed to provide a basis for subsequent MAS.

[0028] S4: Select Zhengmai 7698 with multiple spikes and Chuanmai 93 with large spikes of different marking types as parents for hybridization. Before the wheat blooms, select healthy Zhengmai 7698 with multiple spikes and Chuanmai 93 with large spikes as parents, with Zhengmai 7698 with multiple spikes as the female parent and Chuanmai 93 with large spikes as the male parent. During the flowering period of the female plant, use an emasculating needle to remove anthers to prevent self-pollination. Then, seal the emasculated flowers with bags. After the pollen matures, collect pollen from the male plant and smear it on the stigma of the female plant to complete artificial hybridization. After hybridization, bag the plants again to prevent contamination by other pollen, and mark the hybrid combination for subsequent tracking.

[0029] S5: Screen out individuals with different phenotypes from the hybrid offspring, establish a segregating population, sow the seeds obtained from the hybridization, cultivate them to maturity, observe and record the phenotypic characteristics of each plant, such as ear type, number of ears, etc. Based on the phenotypic characteristics, screen out individuals with multiple ears and large ears.

[0030] S6: Conduct molecular marker analysis on the segregated population, select individuals carrying the target gene, and self-pollinate them. Collect fresh leaves from each plant in the segregated population, extract DNA using a DNA extraction kit, amplify the DNA sample using a PCR instrument using previously designed specific primers, separate the amplified DNA sample using an electrophoresis instrument, observe the electrophoresis results using a gel imaging system, determine the genotype of each individual based on the band pattern, and select individuals carrying the target gene for subsequent self-pollination or reproduction to fix the target trait.

[0031] S7: Conduct phenotype verification on individuals selected through MAS and conduct continuous self-pollination to obtain improved new wheat varieties with multiple ears and large spikes. Plant individuals selected through MAS in the field and carry out conventional agricultural management. Observe and record phenotypic characteristics such as plant growth habits, disease resistance, and yield throughout the growth cycle. Verify the effect of molecular marker-assisted selection through comparative experiments. Conduct continuous self-pollination on individuals with excellent performance to fix excellent traits. Finally, develop stable new varieties with multiple ears and large spikes through multiple generations of selection and self-pollination.

[0032] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A method for breeding new varieties of large-eared wheat, characterized in that: The following steps are involved: S1: Select Zhengmai 7698 and Chuanmai 93 wheat seeds with full grains, uniform color and glossy texture as male and female parents; S2: Mark the molecules related to the multiple-ear traits of Zhengmai 7698 and the large-ear traits of Chuanmai 93, and design specific primers; S3: Using the developed molecular markers, the genetic background of Zhengmai 7698 with multiple spikes and Chuanmai 93 with large spikes were mapped to determine the positional relationship between the markers and the target gene; S4: Select wheat seeds of Zhengmai 7698 with multiple spikes and Chuanmai 93 with large spikes of different marker types as parents for hybridization; S5: Screen out individuals with different phenotypes from the hybrid offspring and establish segregating populations; S6: Perform molecular marker analysis on the segregating population, select individuals carrying the target gene, and make them self-fertilize; S7: Phenotypic verification of individuals selected by MAS is performed, and continuous self-pollination is performed to obtain new improved wheat varieties with multiple and large spikes.

2. The method for breeding new varieties of large-eared wheat according to claim 1, characterized in that: In the step S2, fresh leaves need to be collected from Zhengmai 7698 with multiple ears and Chuanmai 93 with large ears, total DNA is extracted using a DNA extraction kit according to the operating procedures in the instruction manual, specific primers are designed according to known gene sequences using primer design software, the DNA samples are amplified using a PCR instrument, the amplification conditions include pre-denaturation, denaturation, annealing and extension steps, the amplified DNA samples are separated by an electrophoresis instrument, the electrophoresis results are observed and recorded using a gel imaging system, and the polymorphic markers are determined.

3. The method for breeding new varieties of large-eared wheat according to claim 1, characterized in that: In step S3, the molecular marker products amplified by PCR need to be sequenced or genotyped using a molecular marker analysis system. The obtained genotype data are compared with the known genetic map through data analysis software to determine the position of each marker on the chromosome. This process may require the integration and analysis of multiple markers to construct a complete genetic map. After the map is constructed, the linkage relationship between the marker and the target trait is analyzed to provide a basis for subsequent MAS.

4. The method for breeding new varieties of large-eared wheat according to claim 1, characterized in that: In the step of S4, it is necessary to select healthy multi-spike Zhengmai 7698 and large-spike Chuanmai 93 wheat plants as parents before the wheat blooms, wherein the multi-spike Zhengmai 7698 is used as the female parent and the large-spike Chuanmai 93 wheat is used as the male parent. During the flowering period of the female plant, anthers are removed using a emasculating needle to prevent self-pollination. Then, the emasculated flowers are sealed with bags. After the pollen matures, pollen is collected from the male plant and smeared on the stigma of the female plant to complete artificial hybridization. After hybridization, the flowers are bagged again to prevent contamination by other pollen, and the hybrid combination is marked for subsequent tracking.

5. The method for breeding new varieties of large-eared wheat according to claim 1, characterized in that: In the step S5, the hybridized seeds need to be sown, cultivated to maturity, and the phenotypic characteristics of each plant, such as ear type, number of ears, etc., are observed and recorded, and individuals with multiple ears and large ears are screened out based on the phenotypic characteristics.

6. The method for breeding new varieties of large-eared wheat according to claim 1, characterized in that: In the step S6, fresh leaves need to be collected from each plant of the separated group, DNA needs to be extracted using a DNA extraction kit, the DNA samples are amplified by a PCR instrument using previously designed specific primers, the amplified DNA samples are separated by an electrophoresis instrument, the electrophoresis results are observed using a gel imaging system, the genotype of each individual is determined based on the band pattern, and individuals carrying the target gene are selected for subsequent self-pollination or reproduction to fix the target trait.

7. The method for breeding new varieties of large-eared wheat according to claim 1, characterized in that: In the step S7, the individuals selected by MAS need to be planted in the field and subjected to conventional agricultural management. During the entire growth cycle, the phenotypic characteristics of the plants, such as growth habits, disease resistance, and yield, are observed and recorded. Through comparative experiments, the effect of molecular marker-assisted selection is verified, and individuals with excellent performance are continuously self-pollinated to fix the excellent traits. Through multiple generations of selection and self-pollination, a new variety with multiple and large ears of stable panicles is finally bred.

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