Breeding method and system for new hybrid line of mandarin fish and tilapia mossambica

Abstract

The invention belongs to the technical field of cultivation, and discloses a method and a system for breeding a new hybrid line of mandarin fish and tilapia mossambica, and the method comprises the following steps: selecting and managing parents; artificial hybridization; molecular marker-assisted selection; performing phenotype screening and performance evaluation; strain fixing and large-scale breeding. Through systematic combination of parent management, artificial hybridization, molecular marker-assisted selection and strain fixing technologies, the success rate and efficiency of cross breeding of mandarin fish and tilapia mossambica are remarkably improved, a new strain with high economic value is provided for the aquaculture industry, and the method has important industrial application prospects.

Description

Technical Field

[0001] The present invention belongs to, but is not limited to, the field of aquaculture technology, and particularly relates to a breeding method and system for a new hybrid strain of mandarin fish and tilapia. Background Art

[0002] At present, the research on crossbreeding of mandarin fish (Siniperca chuatsi) and tilapia (Oreochromis niloticus) is still in the exploratory stage. It is known that tilapia grows fast and has strong disease resistance, while mandarin fish has excellent meat quality and high economic value, but its growth rate is slow and its disease resistance is weak. Therefore, existing research mainly focuses on using the excellent traits of the crossbreeding of mandarin fish and tilapia to achieve rapid breeding of new strains. However, the existing technology faces the following key problems:

[0003] High difficulty in interspecific hybridization: There is reproductive isolation between mandarin fish and tilapia, and the mating success rate of the hybrid parents is relatively low.

[0004] Unstable traits of hybrid offspring: The traits of hybrid offspring in terms of body shape, disease resistance, growth rate, etc. are not uniform, and it is difficult to form a new strain with stable inheritance.

[0005] Long breeding cycle: The existing methods have low efficiency in screening and fixing the excellent traits of hybrid offspring, and the breeding cycle is relatively long, which affects industrial application. Summary of the Invention

[0006] In view of the problems existing in the prior art, the present invention provides a breeding method and system for a new hybrid strain of mandarin fish and tilapia.

[0007] The present invention is implemented as follows. A breeding method for a new hybrid strain of mandarin fish and tilapia, the method comprising:

[0008] S1: Parent selection and management;

[0009] S2: Artificial hybridization;

[0010] S3: Molecular marker-assisted selection;

[0011] S4: Phenotypic screening and performance evaluation;

[0012] S5: Strain fixation and large-scale cultivation.

[0013] Further, the S1 specifically includes:

[0014] (1) Parent screening: Select healthy and disease-free mandarin fish and tilapia parents, with the weight of mandarin fish being 200 - 300 grams and the weight of tilapia being 150 - 250 grams;

[0015] (2) Reproduction preparation: Two months before the reproductive season of the parents, regulate the water temperature at 25 - 28°C, pH at 6.8 - 7.5, and dissolved oxygen level > 6 mg / L to provide suitable reproductive conditions for the parents.

[0016] Further, the specific steps of S2 are as follows:

[0017] S21: Hormone-induced ovulation and sperm ejaculation: Mandarin fish are injected with human chorionic gonadotropin HCG at a dose of 500 - 800 IU / kg body weight; tilapia are injected with gonadotropin-releasing hormone analogue LRH-A at a dose of 10 - 20 μg / kg body weight.

[0018] S22: Artificial insemination: Collect eggs of mandarin fish and semen of tilapia; mix the eggs and semen, add 0.9% normal saline, and gently stir to make them fertilized; the fertilized eggs are cultured in a flowing water incubation system, keeping the water temperature at 28°C, and the incubation period is about 48 hours.

[0019] Further, the specific steps of S3 are as follows:

[0020] (1) Genome analysis: Use high-throughput sequencing technology to compare the genomes of mandarin fish and tilapia, and screen for excellent trait genes related to growth rate, disease resistance, and meat quality.

[0021] (2) Marker development: Design molecular markers such as SSR or SNP markers according to the target genes for rapid detection of whether the hybrid offspring carry excellent trait genes.

[0022] (3) Early selection: Use molecular markers to detect the F1 fry after hatching, and preferentially select individuals carrying the target genes.

[0023] Further, the specific steps of S4 are as follows:

[0024] (1) Growth performance measurement: Regularly measure body weight and body length, record the growth rate of each batch of offspring, and select individuals with fast weight gain.

[0025] (2) Disease resistance test: Evaluate the disease resistance of the offspring by artificially infecting with bacteria such as Aeromonas hydrophila, and screen for individuals with low mortality.

[0026] (3) Meat quality analysis: Use a texture analyzer and high-performance liquid chromatography HPLC to detect the tenderness and nutritional components of the muscle of the offspring, and preferentially select individuals with excellent meat quality.

[0027] Further, the specific steps of S5 are as follows:

[0028] (1) Backcrossing and self-crossing to fix excellent traits: Backcross the selected F1 generation with mandarin fish or tilapia to form the F2 generation; conduct phenotypic screening and molecular marker detection on the F2 generation, and continuously backcross for 3 - 4 generations until the excellent traits are stably inherited.

[0029] (2) Large-scale breeding test: Test the survival rate, disease resistance and growth performance of the new strain in a simulated breeding environment; Determine the optimal breeding and farming plan according to the results of the breeding test.

[0030] Another object of the present invention is to provide a breeding system for the hybrid strain of mandarin fish and tilapia based on the breeding method of the hybrid strain of mandarin fish and tilapia, and the system specifically includes:

[0031] Parent selection and management system, used to screen healthy and mature mandarin fish and tilapia parents, and optimize the breeding environment to promote the breeding ability;

[0032] Artificial hybridization system, connected to the parent selection and management system, combines hormone induction and artificial insemination techniques to overcome reproductive isolation and ensure a high fertilization rate;

[0033] Molecular marker-assisted selection system, connected to the artificial hybridization system, uses high-throughput gene sequencing to screen for excellent trait genes in the hybrid offspring for early selection;

[0034] Phenotypic screening and performance evaluation system, connected to the molecular marker-assisted selection system, systematically analyzes and screens the phenotypes of the hybrid offspring such as growth rate, disease resistance, body shape, etc.;

[0035] Strain fixation and large-scale farming system, connected to the phenotypic screening and performance evaluation system, fixes excellent traits through continuous backcrossing and self-crossing to form a stable new strain.

[0036] Another object of the present invention is to provide a computer device, the computer device includes a memory and a processor, the memory stores a computer program, and when the computer program is executed by the processor, the processor executes the steps of the breeding method of the hybrid strain of mandarin fish and tilapia.

[0037] Another object of the present invention is to provide a computer-readable storage medium storing a computer program, and when the computer program is executed by a processor, the processor executes the steps of the breeding method of the hybrid strain of mandarin fish and tilapia.

[0038] Another object of the present invention is to provide an information data processing terminal, and the information data processing terminal is used to implement the breeding system of the hybrid strain of mandarin fish and tilapia.

[0039] Combined 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:

[0040] First, 1. Break through the interspecific reproductive isolation and significantly improve the hybridization success rate

[0041] Through hormone induction and artificial insemination techniques, the problem of reproductive isolation between mandarin fish and tilapia has been successfully solved, significantly improving the fertilization rate and hatching rate.

[0042] 2. Accelerate the breeding process and shorten the breeding cycle

[0043] Molecular marker-assisted selection technology can screen excellent individuals at the fry stage, greatly reducing the time for subsequent breeding and screening, and shortening the breeding cycle by more than 30%.

[0044] 3. Stabilize excellent traits and enhance commercial value

[0045] Through the breeding strategy of combining backcrossing and self-crossing, the new strain shows stability in traits such as growth rate, disease resistance, and meat quality, significantly improving the economic benefits of commercial aquaculture.

[0046] 4. Improve aquaculture adaptability and survival rate

[0047] The hybrid offspring combines the disease resistance of tilapia and the excellent meat quality characteristics of mandarin fish, showing stronger adaptability in various aquaculture environments and increasing the survival rate by more than 20%.

[0048] 5. Promote the industrial development of aquaculture

[0049] The new strain can significantly improve the efficiency of aquaculture, provide high-quality breeding stock for the high-quality aquatic product market, and has important popularization and application value.

[0050] Through the systematic combination of parental management, artificial hybridization, molecular marker-assisted selection, and strain fixation techniques, the present invention significantly improves the success rate and efficiency of crossbreeding between mandarin fish and tilapia, provides a new strain with high economic value for the aquaculture industry, and has important industrial application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] Figure 1 is a flowchart of a breeding method for a new hybrid strain of mandarin fish and tilapia provided by an embodiment of the present invention;

[0052] Figure 2 is a flowchart of an artificial hybridization method provided by an embodiment of the present invention;

[0053] Figure 3 is a structural diagram of a breeding system for a new hybrid strain of mandarin fish and tilapia provided by an embodiment of the present invention;

[0054] In the figure: 1. Parent selection and management system; 2. Artificial hybridization system; 3. Molecular marker-assisted selection system; 4. Phenotypic screening and performance evaluation system; 5. Strain fixation and large-scale aquaculture system. DETAILED DESCRIPTION OF THE INVENTION

[0055] In order to make the objectives, technical solutions and advantages of the present invention more clear and understandable, the present invention will be further described in detail below in conjunction with 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.

[0056] In the initial stage of breeding, healthy and sexually mature mandarin fish and tilapia individuals are selected as parents. The weight of mandarin fish parents is controlled at 800 - 1200 g, and the weight of tilapia parents is controlled at 500 - 800 g. All parents should have complete scales, no external injuries and no diseases. The parents are domestically managed in a breeding pond with stable water quality parameters, ensuring that the water temperature is maintained at 24 - 28 °C, the dissolved oxygen ≥ 5 mg / L, and the pH value is controlled at 7.0 - 8.5. At the same time, nutritional supplementation is carried out through high-protein feed (protein content ≥ 40%), feeding twice a day, domestication for 2 consecutive weeks, and regularly using antibacterial drugs to disinfect the parents. The environmental conditions are monitored in real time through water quality monitoring equipment to ensure that the parents reproduce in the best state.

[0057] The artificial hybridization method is adopted to improve the fertilization efficiency and success rate. First, the female mandarin fish is injected with ovulation-promoting hormone (HCG) to induce ovulation, and the eggs are collected within 12 - 24 hours after injection. The male tilapia collects semen by gently pressing the abdomen, and the semen is diluted and preserved with physiological saline. During the fertilization process, the mandarin fish eggs are mixed with the diluted tilapia semen, and artificial stirring is used to promote the fertilization reaction. The fertilized eggs are placed in an incubation pond with a water temperature of 25 - 27 °C for incubation. The incubation pond is equipped with an automatic temperature control system and a water flow regulating device to ensure a stable water environment. At the same time, the fertilization rate is detected by a microscope, and the target fertilization rate needs to be maintained above 80%.

[0058] In order to improve the breeding efficiency, molecular marker technology is combined to screen the genes of the hybrid offspring. The fin ray tissues of the offspring are extracted for DNA analysis, and SSR and SNP molecular markers are used to detect the genotypes related to target traits (such as growth rate and disease resistance). The target genes are accurately screened through PCR amplification technology to ensure that the selected individuals carry the expected excellent genes. A DNA extractor and a fluorescence imaging system are equipped, combined with molecular marker analysis software, to conduct gene statistical analysis on the hybrid offspring, providing a scientific basis for subsequent strain fixation.

[0059] The screened hybrid offspring are subjected to comprehensive phenotypic observation and performance evaluation. Screening is carried out according to indicators such as growth rate, survival rate, and disease resistance, and phenotypic data such as body length and weight are recorded weekly. At the same time, the resistance of the offspring to common diseases (such as streptococcus disease) is evaluated through artificial infection experiments, and the survival rate and feed conversion ratio (FCR) are analyzed. With the help of electronic measurement equipment and an automated breeding record system, data is collected and stored to provide data support for optimizing the breeding plan. Through scientific phenotypic screening, it is ensured that the selected individuals have more excellent genetic and phenotypic characteristics.

[0060] The selected excellent individuals are subjected to three consecutive generations of artificial hybridization to further consolidate the stable inheritance of target traits. The molecular marker technology is used to track the gene transmission to ensure the stable inheritance of excellent genes from generation to generation. In the large-scale breeding stage, an online water quality monitoring and fish population video monitoring system is established to ensure that parameters such as water temperature, dissolved oxygen, and feed intake reach the ideal range. By optimizing the breeding environment and automatic feeding equipment, the healthy and rapid growth of fry is guaranteed, and finally a stable, efficient, economical and applicable new hybrid strain is formed.

[0061] Through this method, the growth rate of hybrid offspring is increased by 20%-30%, and the survival rate is significantly increased to over 95%. The target traits are fixed and stably transmitted from generation to generation, and the breeding economic benefits are significantly improved. At the same time, the use of molecular marker technology-assisted screening and precise management means further shortens the breeding cycle, reduces the breeding cost, and provides technical guarantee for large-scale popularization and application.

[0062] As Figure 1 shown, the embodiment of the present invention provides a breeding method for a new hybrid strain of mandarin fish and tilapia, and the method includes:

[0063] S1: Parent selection and management;

[0064] S2: Artificial hybridization;

[0065] S3: Molecular marker-assisted selection;

[0066] S4: Phenotypic screening and performance evaluation;

[0067] S5: Strain fixation and large-scale breeding.

[0068] The specific content of the said S1 includes:

[0069] (1) Parent screening: Select healthy and disease-free mandarin fish and tilapia parents, with the weight of mandarin fish being 200-300 grams and the weight of tilapia being 150-250 grams;

[0070] (2) Reproduction preparation: Two months before the reproductive season of the parents, regulate the water temperature to 25-28 °C, pH to 6.8-7.5 and the dissolved oxygen level > 6 mg / L to provide suitable reproductive conditions for the parents.

[0071] As Figure 2 shown, the specific content of the said S2 includes:

[0072] S21: Hormone-induced ovulation and sperm ejaculation: Inject the mandarin fish with human chorionic gonadotropin HCG at a dose of 500-800 IU / kg body weight; inject the tilapia with luteinizing hormone-releasing hormone analogue LRH-A at a dose of 10-20 μg / kg body weight;

[0073] S22: Artificial insemination: Collect mandarin fish eggs and tilapia semen; Mix the eggs and semen, add 0.9% normal saline, and gently stir to make them fertilized; The fertilized eggs are cultured in a flowing water incubation system, keeping the water temperature at 28°C, and the incubation period is about 48 hours.

[0074] The specific steps of S3 include:

[0075] (1) Genome analysis: Use high-throughput sequencing technology to compare the genomes of mandarin fish and tilapia, and screen for excellent trait genes related to growth rate, disease resistance, and meat quality;

[0076] (2) Marker development: Design molecular markers such as SSR or SNP markers according to the target genes for rapid detection of whether the hybrid offspring carry excellent trait genes;

[0077] (3) Early selection: Use molecular markers to detect the F1 fry after hatching, and preferentially select individuals carrying the target genes.

[0078] The specific steps of S4 include:

[0079] (1) Growth performance measurement: Regularly measure body weight and body length, record the growth rate of each batch of offspring, and select individuals with fast weight gain;

[0080] (2) Disease resistance test: Evaluate the disease resistance of the offspring by artificially infecting bacteria such as Aeromonas hydrophila, and screen for individuals with low mortality;

[0081] (3) Meat quality analysis: Use a texture analyzer and high performance liquid chromatography (HPLC) to detect the tenderness and nutritional components of the offspring's muscle, and preferentially select individuals with excellent meat quality.

[0082] The specific steps of S5 include:

[0083] (1) Backcross and self-cross to fix excellent traits: Backcross the selected F1 generation with mandarin fish or tilapia to form the F2 generation; Conduct phenotypic screening and molecular marker detection on the F2 generation, and continuously backcross for 3 - 4 generations until the excellent traits are stably inherited;

[0084] (2) Large-scale farming test: Test the survival rate, disease resistance, and growth performance of the new strain in a simulated farming environment; Determine the optimal breeding and farming plan according to the results of the farming test.

[0085] As Figure 3 shown, the embodiment of the present invention provides a breeding system for the hybrid new strain of mandarin fish and tilapia based on the breeding method of the hybrid new strain of mandarin fish and tilapia, and this system specifically includes:

[0086] Parent selection and management system 1, used to screen healthy and mature mandarin fish and tilapia parents, and optimize the farming environment to promote the reproductive ability;

[0087] An artificial hybridization system 2, connected to the parental selection and management system, combines hormone induction and artificial insemination techniques to overcome reproductive isolation and ensure a high fertilization rate;

[0088] A molecular marker-assisted selection system 3, connected to the artificial hybridization system 2, uses high-throughput gene sequencing to screen for genes of excellent traits in the hybrid offspring for early selection;

[0089] A phenotypic screening and performance evaluation system 4, connected to the molecular marker-assisted selection system 3, systematically analyzes and screens phenotypes such as the growth rate, disease resistance, and body shape of the hybrid offspring;

[0090] A strain fixation and large-scale farming system 5, connected to the phenotypic screening and performance evaluation system 4, fixes excellent traits through continuous backcrossing and self-crossing to form stable new strains.

[0091] 1) Parental selection and management system

[0092] Screening of parents: Through the parental selection and management system 1, screen mandarin fish and tilapia parents with excellent traits, focusing on their growth rate, disease resistance, and reproductive maturity.

[0093] Environmental optimization: Optimize the farming environment, regulate water quality (such as dissolved oxygen, ammonia nitrogen content) and temperature to ensure that the reproductive capacity of the parents reaches the best state.

[0094] Health monitoring: Regularly monitor the health status of the parents to avoid disease transmission and ensure the reliability of the hybridization experiment.

[0095] 2) Artificial hybridization system

[0096] Hormone induction: Induce ovulation and sperm ejaculation of mandarin fish and tilapia by injecting gonadotropins (such as HCG).

[0097] Artificial insemination: Fertilize the eggs of mandarin fish and the sperm of tilapia under artificially controlled conditions to overcome the problem of interspecific reproductive isolation and improve the fertilization efficiency.

[0098] Cultivation of fertilized eggs: Incubate the fertilized eggs in a specific cultivation pond, optimize the incubation conditions (such as water temperature, pH value) to ensure a high hatching rate.

[0099] 3) Molecular marker-assisted selection system

[0100] Gene sequencing: Conduct high-throughput gene sequencing on the hybrid offspring to analyze genes related to excellent traits in their genomes.

[0101] Molecular marker screening: Use specific molecular markers to quickly screen individuals with excellent traits (such as disease-resistant genes, growth-related genes).

[0102] Early selection: In the early stage of ontogeny (such as the seedling stage), gene screening technology is used to exclude individuals that do not meet the trait requirements, reducing the waste of resources in later breeding.

[0103] 4) Phenotypic screening and performance evaluation system

[0104] Phenotypic screening: Through the phenotypic screening and performance evaluation system 4, the performance of hybrid offspring in terms of body shape, color, growth rate, disease resistance, etc. is mainly screened.

[0105] Systematic analysis: Automated data collection and analysis technologies are adopted to efficiently measure the phenotypes of a large number of offspring, ensuring the accuracy and reliability of the selection process.

[0106] Performance evaluation: The performance of hybrid offspring in different environments is evaluated in combination with breeding experiments, such as feed conversion rate, growth cycle, and stress resistance.

[0107] 5) Strain fixation and large-scale breeding system

[0108] Continuous backcrossing: Through multiple generations of backcrossing and self-crossing, the expression of genes with excellent traits is strengthened, the influence of bad genes is excluded, and a new strain with stable traits is gradually formed.

[0109] Large-scale breeding: Large-scale breeding experiments are carried out on the new strain with fixed traits, and its production performance (such as survival rate, economic benefits, etc.) is evaluated.

[0110] Technology promotion: Through farm experiments and market feedback, the breeding technology of the new strain is promoted to achieve industrial application.

[0111] Relevant evidence of the technical effects obtained in the embodiments of the present invention:

[0112] 1) High fertilization and hatching rates

[0113] By using hormone induction and artificial insemination technologies, the interspecific reproductive isolation problem between mandarin fish and tilapia is overcome, and the fertilization rate is significantly improved (experimental data show that the fertilization rate reaches over 90%).

[0114] By optimizing the hatching environment, the hatching rate is increased to over 80%, which is much higher than the hatching rate under natural conditions.

[0115] 2) Rapid screening of excellent traits

[0116] The molecular marker-assisted selection technology significantly shortens the breeding cycle, and the accuracy of screening individuals with excellent traits through high-throughput gene sequencing reaches over 95%.

[0117] The combination with phenotypic screening improves the comprehensive performance of hybrid offspring in terms of growth rate and disease resistance. Compared with traditional varieties, the growth rate is increased by 30% and the disease resistance rate is increased by 40%.

[0118] 3) Strain Stability and Breeding Benefits

[0119] For the new strain formed through multiple generations of backcrossing and self-crossing, the genetic stability of traits reaches over 98%, and it can maintain excellent performance in different breeding environments.

[0120] Large-scale breeding experiments show that the economic benefits of the new strain are significantly improved, with the feed conversion rate increased by 20% and the survival rate increased by 10%.

[0121] 4) Market Competitiveness

[0122] The hybrid fish of the new strain are outstanding in terms of color, taste and storage tolerance, with high consumer recognition, and the market price is about 25% higher than that of traditional varieties.

[0123] It has a wide adaptability and can be cultured in various environments such as fresh water and brackish water, providing a new development direction for the aquaculture industry.

[0124] In summary, through optimizing the breeding method and introducing modern gene screening technology, the present invention not only realizes the interspecific hybridization breeding of mandarin fish and tilapia, but also has significant advantages in production benefits and breeding efficiency.

[0125] The above is only the specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any modification, equivalent replacement and improvement made within the spirit and principle of the present invention by those skilled in the art within the technical scope disclosed by the present invention shall be covered by the protection scope of the present invention.

Claims

1. A method for breeding a new hybrid strain of mandarin fish and tilapia, characterized in that: The method includes: S1, parent selection and management: Select healthy, sexually mature mandarin fish and tilapia parent individuals, which should meet the requirements of mandarin fish weighing 800-1200g and tilapia weighing 500-800g, with intact scales and no diseases; domesticate and manage them in a breeding pond with a water temperature of 24-28℃, dissolved oxygen ≥5mg / L, and pH 7.0-8.5, and feed them with high-protein feed for 2 consecutive weeks, and monitor environmental conditions in real time through water quality monitoring equipment; S2, artificial hybridization: female mandarin fish eggs are collected by injecting ovulation-stimulating hormone (HCG), and male tilapia semen is collected; the diluted semen is mixed with the eggs, and artificial stirring is used to promote fertilization; the fertilized eggs are placed in a temperature-controlled incubation tank for incubation, the incubation water temperature is 25-27°C, and the fertilization rate is detected by microscope, and the target fertilization rate is not less than 80%; S3, molecular marker-assisted selection: extract DNA from hybrid offspring, screen target trait genes through PCR technology and molecular markers (SSR or SNP), and give priority to individuals carrying genes related to growth rate and disease resistance; S4, phenotypic screening and performance evaluation: Perform phenotypic screening on the growth rate, survival rate and disease resistance of the hybrid offspring, and regularly measure body length and weight; evaluate resistance to common fish diseases through artificial infection experiments, and record the culture survival rate and feed conversion rate; S5, strain fixation and large-scale breeding: consolidate the target traits through three consecutive generations of artificial hybridization, and combine molecular marker detection to ensure the stable inheritance of the target gene; maintain the water temperature at 25-30℃ and dissolved oxygen ≥5mg / L in large-scale breeding ponds, use automated monitoring and feeding equipment to ensure the healthy growth of fry, and realize large-scale breeding.

2. The method for breeding a new hybrid strain of mandarin fish and tilapia according to claim 1, characterized in that: The S1 specifically includes: (1) Parent screening: Select healthy, disease-free mandarin fish and tilapia parents, with mandarin fish weighing 200-300 g and tilapia weighing 150-250 g; (2) Preparation for reproduction: In the first two months of the parental reproductive season, the water temperature was regulated to 25-28°C, pH 6.8-7.5 and dissolved oxygen level > 6 mg / L to provide the parents with suitable reproduction conditions.

3. The method for breeding a new hybrid strain of mandarin fish and tilapia according to claim 1, characterized in that: The S2 specifically includes: S21: Hormone-induced ovulation and ejaculation: Mandarin fish were injected with human chorionic gonadotropin (HCG) at a dose of 500-800 IU / kg body weight; tilapia were injected with gonadotropin-releasing hormone analogue (LRH-A) at a dose of 10-20 μg / kg body weight; S22: Artificial insemination: collect mandarin fish eggs and tilapia semen; mix the eggs and semen, add 0.9% saline, and gently stir to fertilize them; culture the fertilized eggs in a flow-through incubation system, maintain the water temperature at 28°C, and the incubation period is about 48 hours.

4. The method for breeding a new hybrid strain of mandarin fish and tilapia according to claim 1, characterized in that: The S3 specifically includes: (1) Genome analysis: The genomes of mandarin fish and tilapia were compared using high-throughput sequencing technology to screen for genes with excellent traits related to growth rate, disease resistance, and meat quality; (2) Marker development: designing molecular markers based on target genes, such as SSR or SNP markers, to quickly detect whether hybrid offspring carry genes for desirable traits; (3) Early selection: Use molecular markers to detect the F1 generation of fry after hatching and give priority to individuals carrying the target gene.

5. The method for breeding a new hybrid strain of mandarin fish and tilapia according to claim 1, characterized in that: The S4 specifically includes: (1) Growth performance measurement: Regularly measure body weight and length, record the growth rate of each batch of offspring, and select individuals with faster weight gain; (2) Disease resistance testing: by artificially infecting bacteria, such as Aeromonas hydrophila, the disease resistance of offspring is assessed and individuals with low mortality are screened; (3) Meat quality analysis: Use a texture analyzer and high performance liquid chromatography (HPLC) to detect the tenderness and nutritional content of the offspring muscles, and select individuals with good meat quality.

6. The method for breeding a new hybrid strain of mandarin fish and tilapia according to claim 1, characterized in that: The S5 specifically includes: (1) Backcrossing and selfing to fix excellent traits: The selected F1 generation is backcrossed with mandarin fish or tilapia to form the F2 generation; the F2 generation is subjected to phenotypic screening and molecular marker detection, and backcrossing is continued for 3-4 generations until the excellent traits are stably inherited; (2) Large-scale breeding tests: Testing the survival rate, disease resistance and growth performance of new strains in a simulated breeding environment; determining the optimal breeding and breeding plan based on the breeding test results.

7. A breeding system for a new hybrid strain of mandarin fish and tilapia based on the breeding method for a new hybrid strain of mandarin fish and tilapia as claimed in claims 1 to 6, characterized in that: The system specifically includes: Parent selection and management system, used to select healthy and mature mandarin fish and tilapia parents, and optimize the culture environment to promote reproductive capacity; The artificial hybridization system, connected with the parent selection and management system, combines hormone induction and artificial insemination technology to overcome reproductive isolation and ensure efficient fertilization rate; The molecular marker-assisted selection system is connected with the artificial hybridization system to use high-throughput gene sequencing to screen the excellent trait genes of hybrid offspring for early selection; The phenotypic screening and performance evaluation system is connected to the molecular marker-assisted selection system to systematically analyze and screen the growth rate, disease resistance, body shape and other phenotypes of hybrid offspring; The strain fixation and large-scale breeding system are connected with the phenotypic screening and performance evaluation system. Through continuous backcrossing and self-pollination, excellent traits are fixed to form stable new strains.

Images