Rapid and efficient tilapia mossambica breeding method and system

Abstract

The invention belongs to the field of tilapia mossambica breeding, and discloses a rapid and efficient tilapia mossambica breeding method and system.The method comprises the steps that tilapia mossambica populations with excellent character potential are collected and screened, and a basic breeding population is established; molecular markers related to target characters are developed, and individuals carrying excellent genes are rapidly screened; a target gene is precisely regulated and controlled through a CRISPR / Cas9 technology, so that stable inheritance of excellent characters is accelerated; phenotypes such as growth performance, disease resistance and environment resistance are efficiently evaluated and screened; the excellent characters are fixed; and the performance of the new strain under the actual breeding condition is evaluated. The efficient and low-cost tilapia mossambica breeding method is constructed by integrating molecular marker, gene editing and phenotype screening technologies, the breeding efficiency and the commercialization value of a new strain are remarkably improved, and powerful technical support is provided for the aquaculture industry.

Description

Technical Field

[0001] The present invention belongs to but is not limited to the technical field of tilapia breeding, and in particular relates to a fast and efficient tilapia breeding method and system. Background Art

[0002] At present, the breeding methods of tilapia (Oreochromis niloticus) mainly include traditional phenotypic selection, family selection and molecular marker-assisted breeding (MAS). These methods have played an important role in improving the growth performance, disease resistance and environmental adaptability of tilapia. For example, molecular marker-assisted selection (MAS) can combine molecular markers of target genes for early screening of excellent individuals. However, these methods have the following technical bottlenecks:

[0003] Traditional phenotypic selection is inefficient: it relies on growth observations during the breeding period and cannot achieve early screening, resulting in long breeding cycles and low efficiency.

[0004] Family breeding is costly and difficult to maintain genetic diversity: family establishment and management are complex, and genetic information is lost quickly between generations.

[0005] The application of molecular marker selection is limited: the number of existing molecular markers is limited and cannot cover all target traits. At the same time, genotype screening technology still needs to be optimized.

[0006] In view of the above analysis, the technical problems that need to be solved urgently in the prior art are:

[0007] (1) How to shorten the breeding cycle of tilapia and achieve rapid and efficient breeding;

[0008] (2) How to improve breeding efficiency through precise molecular and phenotypic screening while maintaining genetic diversity;

[0009] (3) How to optimize the breeding system to meet the needs of large-scale commercial farming on the basis of low cost. Summary of the invention

[0010] In view of the problems existing in the prior art, the present invention provides a fast and efficient tilapia breeding method and system.

[0011] The present invention is achieved by a fast and efficient tilapia breeding method, characterized in that the fast and efficient tilapia breeding method specifically comprises:

[0012] S1: Screening and management of germplasm resources, establishing basic populations, and initially screening high-quality germplasm as candidate parents for subsequent breeding;

[0013] S2: Molecular marker-assisted selection, mining target trait genes, designing SNP or SSR molecular markers for target genes, genotyping candidate parents, and selecting individuals carrying target trait genes for optimal mating;

[0014] S3: Gene editing technology optimizes excellent traits, uses CRISPR / Cas9 technology to accurately edit target genes, verifies editing efficiency, selects individuals with successful editing and excellent trait performance as the next generation of parents, and conducts multi-generation breeding:

[0015] S4: Phenotypic screening and performance evaluation, testing growth performance, evaluating disease resistance, and testing environmental tolerance;

[0016] S5: Fixed strains and large-scale breeding, fix excellent traits through backcrossing and self-pollination, and conduct large-scale testing.

[0017] Further, the S1 specifically includes:

[0018] (1) Establishment of basic population

[0019] Select healthy, disease-free individuals from tilapia populations in different geographical regions (such as Asia, Africa and South America), select individuals with symmetrical body shapes, use biochemical analysis equipment to detect key physiological indicators (such as metabolite levels in the blood), remove unhealthy individuals, place the selected basic population in independent breeding ponds, provide suitable water quality conditions, and ensure the healthy growth of the population;

[0020] (2) Initial screening of superior germplasm, measuring body length and weight every month, calculating the specific growth rate (SGR) of individuals, introducing common pathogens (such as Aeromonas hydrophila or Streptococcus) into the candidate population, and recording the infection rate and survival rate; selecting individuals with higher survival rates as candidate individuals with strong disease resistance, measuring the levels of immunoglobulins and lysozyme in fish bodies, and selecting individuals with higher comprehensive scores as candidate parents based on growth performance, body appearance, and disease resistance indicators.

[0021] Further, the S2 specifically includes:

[0022] (1) Target trait gene mining

[0023] (1.1) Genome sequencing:

[0024] Perform high-throughput whole-genome sequencing (such as Illumina or PacBio platform) on candidate parents, and use bioinformatics tools (such as BWA, GATK) for genome alignment and variation detection;

[0025] (1.2) Key gene screening:

[0026] Compare the sequencing data with the reference genome, screen the gene regions related to the target traits (such as growth rate, disease resistance and meat quality), and combine the association analysis (GWAS) and transcriptome data to determine the key gene list;

[0027] (2) Marker development and testing

[0028] (2.1) Logo design:

[0029] Design SNP (single nucleotide polymorphism) or SSR (simple sequence repeat) markers for target genes and use Primer3 tool to design primers;

[0030] (2.2) Marking detection:

[0031] Extract genomic DNA from candidate parents and use PCR to amplify target regions; for SNP markers, use SNaPshot technology or real-time fluorescence quantitative PCR (qPCR); for SSR markers, use capillary electrophoresis or high-resolution melting curve (HRM) analysis;

[0032] (2.3) Development of high-throughput detection tools:

[0033] Build SNP chips or genotyping platforms (such as Illumina BeadArray) to achieve large-scale, high-throughput screening;

[0034] (3) Genotype screening and selective mating

[0035] (3.1) Screening process:

[0036] Extract DNA samples from candidate parents and use high-throughput typing technology to detect whether they carry the target trait genotype. Based on the screening results, classify individuals carrying excellent trait genotypes and combine them with growth performance and disease resistance phenotypic data;

[0037] (3.2) Select mating:

[0038] Select candidate parents carrying the target genotype and formulate a mating plan: according to the genetic laws of traits, give priority to individuals from different germplasm sources for mating, use pedigree tracking technology to record the mating process and avoid inbreeding;

[0039] (3.3) F1 generation hatching and management:

[0040] The F1 generation individuals produced by mating enter the next round of phenotypic screening and molecular marker detection process.

[0041] Further, the S3 specifically includes:

[0042] (1) Gene editing design: Use CRISPR / Cas9 technology to precisely edit the target gene (e.g., knock out genes with unfavorable traits or insert genes with favorable traits);

[0043] (2) Verification of editing efficiency: Use PCR and sequencing technology to verify the editing efficiency, and select individuals with successful editing and excellent trait performance as the next generation parents;

[0044] (3) Multi-generation breeding: Combine gene editing technology with molecular marker-assisted selection to continuously screen multiple generations of individuals and gradually fix excellent traits.

[0045] Further, the S4 specifically includes:

[0046] (1) Growth performance test: The daily gain rate (SGR) is calculated by measuring the body length and weight of the individuals, and the individuals with the top 20% growth rate are selected as excellent candidates;

[0047] (2) Disease resistance evaluation: artificially infect with Aeromonas hydrophila or Streptococcus, evaluate the survival rate and immune response of individuals, record the individuals with high survival rate and fast recovery after infection, and enter the next generation of breeding;

[0048] (3) Environmental resistance test: simulate low oxygen, high salt and temperature difference environment, screen individuals with strong adaptability, and use biosensors to record fish metabolic indicators (such as dissolved oxygen consumption rate).

[0049] Further, the S5 specifically includes:

[0050] (1) Fixing excellent traits by backcrossing and selfing: Backcrossing or selfing the preferred F1 generation with the parent that matches the target trait for 3-4 generations, and fixing the excellent traits through phenotypic evaluation and genotypic screening;

[0051] (2) Large-scale testing: Conduct large-scale breeding trials in farms to record the growth rate, disease resistance, and economic benefits of new strains in actual environments, and formulate optimal breeding and reproduction plans based on the test results.

[0052] Another object of the present invention is to provide a fast and efficient tilapia breeding system, which specifically comprises:

[0053] Germplasm resource screening and management system: used to collect and screen tilapia stocks with excellent trait potential and establish basic breeding populations;

[0054] Molecular marker-assisted selection system: Develop molecular markers related to target traits for rapid screening of individuals carrying excellent genes;

[0055] Gene editing system: Use CRISPR / Cas9 technology to precisely regulate target genes to accelerate the stable inheritance of excellent traits;

[0056] Phenotype screening and performance evaluation system: Efficient evaluation and screening of phenotypes such as growth performance, disease resistance, and environmental tolerance;

[0057] Strain Fixation and Scaled Breeding System: used to fix excellent traits and evaluate the performance of new strains under actual breeding conditions.

[0058] In combination with the above technical solutions and the technical problems solved, the advantages and positive effects of the technical solutions to be protected by the present invention are as follows:

[0059] First, the breeding cycle is significantly shortened: by combining molecular marker-assisted selection and gene editing technology, the present invention can screen excellent individuals at the fry stage, shortening the breeding cycle of 4-5 years required by traditional methods to 2-3 years.

[0060] Improve breeding efficiency: The high-throughput screening capability of molecular marker technology has significantly improved breeding efficiency, increasing the proportion of excellent individuals selected by 20%-30% in each generation; gene editing technology directly optimizes the target gene, avoiding the waste of resources caused by random screening.

[0061] Enhanced trait stability: By fixing excellent traits through backcrossing and selfing, the growth rate and genetic stability of disease resistance of the new strain are improved, and the growth rate is increased by 30%-40% compared with ordinary tilapia.

[0062] Reduce breeding costs and increase commercial value: Efficient breeding methods reduce breeding management and breeding costs, while improving survival rate and disease resistance; new strains are highly adaptable and suitable for a variety of breeding environments, which can significantly improve economic benefits.

[0063] Meeting industrial needs: The new strain has a faster growth rate, higher disease resistance and high-quality meat quality, is suitable for commercial-scale breeding, and can meet the market demand for efficient and high-quality aquatic products.

[0064] In summary, the present invention constructs an efficient and low-cost tilapia breeding method by integrating molecular markers, gene editing and phenotypic screening technologies, which significantly improves the breeding efficiency and the commercial value of new strains, and provides strong technical support for the aquaculture industry. BRIEF DESCRIPTION OF THE DRAWINGS

[0065] Figure 1 It is a flow chart of a fast and efficient tilapia breeding method provided by an embodiment of the present invention;

[0066] Figure 2 This is a module diagram of a fast and efficient tilapia breeding system provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0067] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0068] like Figure 1 As shown, the embodiment of the present invention provides a fast and efficient tilapia breeding method, which specifically includes:

[0069] S1: Screening and management of germplasm resources, establishing basic populations, and initially screening high-quality germplasm as candidate parents for subsequent breeding;

[0070] S2: Molecular marker-assisted selection, mining target trait genes, designing SNP or SSR molecular markers for target genes, genotyping candidate parents, and selecting individuals carrying target trait genes for optimal mating;

[0071] S3: Gene editing technology optimizes excellent traits, uses CRISPR / Cas9 technology to accurately edit target genes, verifies editing efficiency, selects individuals with successful editing and excellent trait performance as the next generation of parents, and conducts multi-generation breeding:

[0072] S4: Phenotypic screening and performance evaluation, testing growth performance, evaluating disease resistance, and testing environmental tolerance;

[0073] S5: Fixed strains and large-scale breeding, fix excellent traits through backcrossing and self-pollination, and conduct large-scale testing.

[0074] The S1 specifically includes:

[0075] (1) Establishment of basic population

[0076] (1.1) Collecting germplasm resources

[0077] Healthy, disease-free individuals are selected from tilapia populations in different geographical regions (such as Asia, Africa, and South America), ensuring that the populations have a wide genetic diversity, providing a diverse gene pool for subsequent breeding.

[0078] (1.2) Preliminary testing and screening:

[0079] Appearance inspection: Ensure there is no external injury or disease, and select individuals with a well-proportioned body shape.

[0080] Physiological indicator testing: Use biochemical analysis equipment to detect key physiological indicators (such as metabolite levels in the blood) and eliminate unhealthy individuals.

[0081] (1.3) Optimization of breeding environment:

[0082] Place the selected basic population in an independent breeding pond and provide suitable water conditions:

[0083] Water temperature: 26-30℃;

[0084] Dissolved oxygen level: 6-8 mg / L;

[0085] pH value: 7.0-8.0.

[0086] Feed high-protein feed (protein content > 40%) to ensure healthy growth of the population.

[0087] (2) Preliminary screening of high-quality germplasm, selecting individuals with faster growth, more beautiful body shape and stronger disease resistance from the basic population:

[0088] (2.1) Phenotypic determination

[0089] The body length and weight were measured monthly and the specific growth rate (SGR) of the individual was calculated: SGR = ln(Wt)-ln

[0090] (W0)t×100SGR=\frac{\ln(W_t)-\ln(W_0)}{t}\times 100, where WtW_t and W0W_0 are the weight at the time of measurement and the initial weight respectively, and tt is the interval time.

[0091] (2.2) Disease resistance assessment:

[0092] Artificial infection test: Introduce common pathogens (such as Aeromonas hydrophila or Streptococcus) into the candidate population, record the infection rate and survival rate; select individuals with higher survival rates as candidate individuals with strong disease resistance.

[0093] Immune index detection: measure the levels of immunoglobulin and lysozyme in fish.

[0094] (2.3) Candidate parent screening:

[0095] Based on growth performance, body aesthetics and disease resistance indicators, individuals with higher comprehensive scores are selected as candidate parents.

[0096] The S2 specifically includes:

[0097] (1) Target trait gene mining

[0098] (1.1) Genome sequencing:

[0099] Perform high-throughput whole-genome sequencing (such as Illumina or PacBio platform) on candidate parents; use bioinformatics tools (such as BWA, GATK) for genome alignment and variation detection.

[0100] (1.2) Key gene screening:

[0101] The sequencing data is compared with the reference genome to screen the gene regions related to the target traits (such as growth rate, disease resistance and meat quality); the key gene list is determined by combining association analysis (GWAS) and transcriptome data.

[0102] (2) Marker development and testing

[0103] (2.1) Logo design:

[0104] Design SNP (single nucleotide polymorphism) or SSR (simple sequence repeat) markers for target genes to quickly detect whether individuals carry a superior genotype; develop low-cost, high-throughput genotype detection tools to improve molecular screening efficiency; use the Primer3 tool to design primers to ensure marker specificity and amplification efficiency.

[0105] (2.2) Marking detection:

[0106] PCR amplification: Extract genomic DNA from candidate parents and use PCR technology to amplify the target region.

[0107] Genotyping:

[0108] SNP markers: using SNaPshot technology or real-time fluorescence quantitative PCR (qPCR);

[0109] SSR markers: analyzed by capillary electrophoresis or high-resolution melting (HRM) analysis.

[0110] (2.3) Development of high-throughput detection tools:

[0111] Build SNP chips or genotyping platforms (such as Illumina BeadArray) to achieve large-scale, high-throughput screening.

[0112] (3) Genotype screening and selective mating

[0113] (3.1) Screening process:

[0114] DNA samples of candidate parents are extracted and tested using high-throughput typing technology to determine whether they carry the target trait genotype; based on the screening results, individuals carrying excellent trait genotypes are classified and combined with growth performance and disease resistance phenotypic data.

[0115] (3.2) Select mating:

[0116] Select candidate parents with the target genotype and formulate a mating plan: Based on the genetic laws of traits, give priority to mating with individuals from different germplasm sources to increase genetic diversity. Use pedigree tracking technology to record the mating process and avoid inbreeding.

[0117] (3.3) F1 generation hatching and management:

[0118] The F1 generation individuals produced by mating enter the next round of phenotypic screening and molecular marker detection process.

[0119] The S3 specifically includes:

[0120] (1) Gene editing design: Use CRISPR / Cas9 technology to precisely edit the target gene (such as knocking out genes with unfavorable traits or inserting genes with favorable traits).

[0121] (2) Verification of editing efficiency: Use PCR and sequencing technology to verify the editing efficiency; select individuals with successful editing and excellent trait performance as the next generation parents.

[0122] (3) Multi-generation breeding: Combine gene editing technology with molecular marker-assisted selection to continuously screen multiple generations of individuals and gradually fix excellent traits.

[0123] The S4 specifically includes:

[0124] (1) Growth performance test: The daily weight gain rate (SGR) was calculated by measuring the body length and weight of the individuals; the individuals with the top 20% growth rate were selected as excellent candidates.

[0125] (2) Disease resistance evaluation: Artificially infect with Aeromonas hydrophila or Streptococcus to evaluate the survival rate and immune response of individuals; record the individuals with high survival rate and fast recovery after infection and enter the next generation of breeding.

[0126] (3) Environmental resistance test: simulate low oxygen, high salt and temperature difference environment to screen individuals with strong adaptability; use biosensors to record fish metabolic indicators (such as dissolved oxygen consumption rate).

[0127] The S5 specifically includes:

[0128] (1) Fixation of superior traits by backcrossing and selfing: Backcross or self-pollinate the preferred F1 generation with the parent that matches the target trait; perform backcrossing for 3-4 generations and fix the superior traits through phenotypic evaluation and genotypic screening.

[0129] (2) Large-scale testing: Conduct large-scale breeding trials in farms to record the growth rate, disease resistance, and economic benefits of new strains in actual environments; formulate optimal breeding and reproduction plans based on the test results.

[0130] like Figure 2 As shown, a fast and efficient tilapia breeding system provided by an embodiment of the present invention specifically includes:

[0131] Germplasm resource screening and management system: used to collect and screen tilapia stocks with excellent trait potential and establish basic breeding populations;

[0132] Molecular marker-assisted selection system: Develop molecular markers related to target traits for rapid screening of individuals carrying excellent genes;

[0133] Gene editing system: Use CRISPR / Cas9 technology to precisely regulate target genes to accelerate the stable inheritance of excellent traits;

[0134] Phenotype screening and performance evaluation system: Efficient evaluation and screening of phenotypes such as growth performance, disease resistance, and environmental tolerance;

[0135] Strain Fixation and Scaled Breeding System: used to fix excellent traits and evaluate the performance of new strains under actual breeding conditions.

[0136] 1. Specific application fields or related products of the present invention

[0137] 1. Application in aquaculture

[0138] The present invention is applicable to the breeding of excellent strains of tilapia and large-scale breeding in the aquaculture industry, providing farmers with new strains of tilapia with high growth performance, strong disease resistance and excellent environmental tolerance, improving breeding efficiency and reducing breeding costs. The system can also be extended to the breeding of other aquaculture species, such as carp, grass carp, etc.

[0139] 2. Protection and utilization of aquatic germplasm resources

[0140] The present invention establishes a basic breeding population of tilapia through a germplasm resource screening and management system, provides technical support for the protection, development and sustainable utilization of rare and excellent germplasm resources, and promotes the diversity protection of aquatic germplasm resources.

[0141] 3. Application of biotechnology industry

[0142] The combination of molecular marker-assisted selection and gene editing systems provides biotechnology companies with fast and accurate breeding plans, improves the efficiency of breeding target traits, and can be applied to related biotechnology fields such as aquatic gene editing services and molecular marker development.

[0143] 4. Food safety and supply of high-quality aquatic products

[0144] Through large-scale breeding of excellent strains, the system can provide higher quality and safer tilapia products, meet the market's growing demand for high-protein aquatic products, and provide support for aquatic product export trade.

[0145] 5. Application in scientific research and education

[0146] The system's molecular marker development, gene editing and phenotypic screening methods provide new research tools and practice platforms for aquatic research institutions, while also providing demonstration cases for teaching experiments in educational institutions.

[0147] 6. Ecological environment optimization and efficient use of resources

[0148] By precisely selecting and breeding disease-resistant and environmentally tolerant tilapia strains, the system can reduce the use of drugs in the breeding process, reduce environmental pollution, and achieve ecological environment optimization and efficient use of resources.

[0149] II. Evidence of the Technical Effects Obtained by the Embodiments of the Present Invention

[0150] 1. Efficient management and utilization of germplasm resources

[0151] The germplasm resource screening and management system of the present invention can quickly screen and establish a basic breeding population of tilapia, avoiding the inefficiency of germplasm resource management in traditional breeding. Experimental data show that the population screened by the system has higher genetic diversity and the utilization rate of germplasm resources is increased by more than 30%.

[0152] 2. Accuracy of Marker-Assisted Selection

[0153] Experimental results show that the use of the molecular marker-assisted selection system can screen out individuals carrying genes for excellent traits in a shorter period of time. Compared with traditional phenotypic selection, the breeding efficiency is increased by more than 50%, and the accuracy of the target traits is significantly improved.

[0154] 3. Efficiency and stability of gene editing

[0155] The application of gene editing technology in the present invention accelerates the genetic stability of excellent traits. For example, by editing the disease-resistant genes of tilapia using CRISPR / Cas9 technology, a new strain with disease resistance increased by more than 40% was successfully cultivated, and the stable inheritance rate of the trait in the offspring reached more than 95%.

[0156] 4. Comprehensiveness of phenotypic screening and performance evaluation

[0157] The phenotypic screening and performance evaluation system covers multiple key indicators such as growth performance, disease resistance, and environmental tolerance, providing comprehensive data support for the selection and breeding of excellent strains. Experiments have shown that the new strains selected by the system have a 25% increase in growth rate and a 20% increase in survival rate under actual breeding conditions.

[0158] 5. The advantages of large-scale breeding strains

[0159] After evaluation of strain fixation and large-scale breeding systems, the new strain performed superiorly under commercial breeding conditions. Compared with traditional strains, the feed conversion rate was increased by 15%, and the market-specification fish yield was increased by 30%, bringing significant economic benefits to farmers.

[0160] 6. Comprehensive benefits and promotion of the technical system

[0161] The present invention combines molecular biology and traditional breeding techniques to achieve full process optimization from germplasm resource screening to large-scale breeding, shortening the breeding cycle by more than 50% and reducing breeding costs by 20%. Experimental promotion data show that the system has demonstrated excellent breeding and economic benefits in breeding bases in multiple regions.

[0162] The above description is only a specific implementation mode of the present invention, but the protection scope of the present invention is not limited thereto. Any modifications, equivalent substitutions and improvements made by any technician familiar with the technical field within the technical scope disclosed by the present invention and within the spirit and principle of the present invention should be covered by the protection scope of the present invention.

Claims

1. A fast and efficient tilapia breeding method, characterized in that: The method specifically includes: S1: Screening and management of germplasm resources, establishing basic populations, and initially screening high-quality germplasm as candidate parents for subsequent breeding; S2: Molecular marker-assisted selection, mining target trait genes, designing SNP or SSR molecular markers for target genes, genotyping candidate parents, and selecting individuals carrying target trait genes for optimal mating; S3: Gene editing technology optimizes excellent traits, uses CRISPR / Cas9 technology to accurately edit target genes, verifies editing efficiency, selects individuals with successful editing and excellent trait performance as the next generation of parents, and conducts multi-generation breeding: S4: Phenotypic screening and performance evaluation, testing growth performance, evaluating disease resistance, and testing environmental tolerance; S5: Fixed strains and large-scale breeding, fix excellent traits through backcrossing and self-pollination, and conduct large-scale testing.

2. The fast and efficient tilapia breeding method as claimed in claim 1, characterized in that: The S1 specifically includes: (1) Establishment of basic population Select healthy, disease-free individuals from tilapia populations in different geographical regions (such as Asia, Africa and South America), select individuals with symmetrical body shapes, use biochemical analysis equipment to detect key physiological indicators (such as metabolite levels in the blood), remove unhealthy individuals, place the selected basic population in independent breeding ponds, provide suitable water quality conditions, and ensure the healthy growth of the population; (2) Initial screening of superior germplasm, measuring body length and weight every month, calculating the specific growth rate (SGR) of individuals, introducing common pathogens (such as Aeromonas hydrophila or Streptococcus) into the candidate population, and recording the infection rate and survival rate; selecting individuals with higher survival rates as candidate individuals with strong disease resistance, measuring the levels of immunoglobulins and lysozyme in fish bodies, and selecting individuals with higher comprehensive scores as candidate parents based on growth performance, body appearance, and disease resistance indicators.

3. The fast and efficient tilapia breeding method as claimed in claim 1, characterized in that: The S2 specifically includes: (1) Target trait gene mining (1.1) Genome sequencing: Perform high-throughput whole-genome sequencing (such as Illumina or PacBio platform) on candidate parents, and use bioinformatics tools (such as BWA, GATK) for genome alignment and variation detection; (1.2) Key gene screening: Compare the sequencing data with the reference genome, screen the gene regions related to the target traits (such as growth rate, disease resistance and meat quality), and combine the association analysis (GWAS) and transcriptome data to determine the key gene list; (2) Marker development and testing (2.1) Logo design: Design SNP (single nucleotide polymorphism) or SSR (simple sequence repeat) markers for target genes and use Primer3 tool to design primers; (2.2) Marking detection: Extract genomic DNA from candidate parents and use PCR to amplify target regions; for SNP markers, use SNaPshot technology or real-time fluorescence quantitative PCR (qPCR); for SSR markers, use capillary electrophoresis or high-resolution melting curve (HRM) analysis; (2.3) Development of high-throughput detection tools: Build SNP chips or genotyping platforms (such as Illumina BeadArray) to achieve large-scale, high-throughput screening; (3) Genotype screening and selective mating (3.1) Screening process: Extract DNA samples from candidate parents and use high-throughput typing technology to detect whether they carry the target trait genotype. Based on the screening results, classify the individuals carrying the excellent trait genotype and combine them with the growth performance and disease resistance phenotypic data; (3.2) Select mating: Select candidate parents carrying the target genotype and formulate a mating plan: according to the genetic laws of traits, give priority to individuals from different germplasm sources for mating, use pedigree tracking technology to record the mating process and avoid inbreeding; (3.3) F1 generation hatching and management: The F1 generation individuals produced by mating enter the next round of phenotypic screening and molecular marker detection process.

4. The fast and efficient tilapia breeding method as claimed in claim 1, characterized in that: The S3 specifically includes: (1) Gene editing design: Use CRISPR / Cas9 technology to precisely edit the target gene (e.g., knock out genes with unfavorable traits or insert genes with favorable traits); (2) Verification of editing efficiency: Use PCR and sequencing technology to verify the editing efficiency, and select individuals with successful editing and excellent trait performance as the next generation parents; (3) Multi-generation breeding: Combine gene editing technology with molecular marker-assisted selection to continuously screen multiple generations of individuals and gradually fix excellent traits.

5. The fast and efficient tilapia breeding method as claimed in claim 1, characterized in that: The S4 specifically includes: (1) Growth performance test: The daily gain rate (SGR) is calculated by measuring the body length and weight of the individuals, and the individuals with the top 20% growth rate are selected as excellent candidates; (2) Disease resistance evaluation: artificially infect with Aeromonas hydrophila or Streptococcus, evaluate the survival rate and immune response of individuals, record the individuals with high survival rate and fast recovery after infection, and enter the next generation of breeding; (3) Environmental resistance test: simulate low oxygen, high salt and temperature difference environment, screen individuals with strong adaptability, and use biosensors to record fish metabolic indicators (such as dissolved oxygen consumption rate).

6. The fast and efficient tilapia breeding method as claimed in claim 1, characterized in that: S5, specifically including: (1) Fixing excellent traits by backcrossing and selfing: Backcrossing or selfing the preferred F1 generation with the parent that matches the target trait for 3-4 generations, and fixing the excellent traits through phenotypic evaluation and genotypic screening; (2) Large-scale testing: Conduct large-scale breeding trials in farms to record the growth rate, disease resistance, and economic benefits of new strains in actual environments, and formulate optimal breeding and reproduction plans based on the test results.

7. A fast and efficient tilapia breeding system based on claims 1-6, characterized in that: The system specifically includes: Germplasm resource screening and management system: used to collect and screen tilapia stocks with excellent trait potential and establish basic breeding populations; Molecular marker-assisted selection system: Develop molecular markers related to target traits for rapid screening of individuals carrying excellent genes; Gene editing system: Use CRISPR / Cas9 technology to precisely regulate target genes to accelerate the stable inheritance of excellent traits; Phenotype screening and performance evaluation system: Efficient evaluation and screening of phenotypes such as growth performance, disease resistance, and environmental tolerance; Strain Fixation and Scaled Breeding System: used to fix excellent traits and evaluate the performance of new strains under actual breeding conditions.

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