Method for cultivating all-male tetraploid crucian carp

Abstract

The invention relates to the technical field of fish cultivation, in particular to a method for cultivating all-male tetraploid crucian carp, which comprises the following steps of: performing artificial spawning induction by taking gynogenesis homologous diploid crucian carp as a female parent and taking androgenesis homologous diploid crucian carp as a male parent; wherein the sex chromosome type of the gynogenesis homologous diploid crucian carp is XX and generates non-reduced diploid ovum, and the sex chromosome type of a male individual in the androgenesis homologous diploid crucian carp is XY or YY and generates non-reduced diploid sperm; artificial insemination is carried out, obtained fertilized eggs are hatched and cultured to sexual maturity, and survival offspring is the all-male tetraploid crucian carp population. Based on the characteristic that gynogenesis homologous diploid carassius auratus and androgenesis homologous diploid carassius auratus both generate non-reducing gametes, the gynogenesis homologous diploid carassius auratus and the androgenesis homologous diploid carassius auratus are subjected to artificial insemination, and all-male tetraploid The all-male tetraploid crucian carp can reach a sexual maturity state after being only 120 days old, diploid sperms can be stably generated, and the reproductive performance is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of fish cultivation, and particularly relates to a method for cultivating all-male tetraploid crucian carp. Background Art

[0002] Fish unisexual breeding refers to the cultivation of a unisexual fish population through artificial intervention or genetic regulation techniques to meet the needs of specific gender fish in aquaculture. Unisexual breeding is of great significance in aquaculture. For example, all-male populations usually grow faster and are larger in size, which can shorten the breeding cycle and reduce production costs; while all-female populations may have higher economic value in some species, such as egg production. The main technical methods of common fish unisexual breeding include sex control techniques using exogenous sex hormones to induce sex reversal, gynogenesis and androgenesis techniques, and the combination of gene editing and sex marker-assisted breeding techniques. Currently, the more widely used unisexual breeding technology is mainly the combination of gynogenesis and sex reversal and other techniques, which is also a way to obtain all-female fish. Artificial sex reversal has been achieved in many fish species, such as medaka, carp, crucian carp, and Clarias leather, making it possible to prepare unisexual fish populations. However, in the process of feeding experimental fish with exogenous sex hormones in the conventional unisexual breeding scheme, the sex reversal ratio is uncontrollable, and it will also cause certain pollution to the water environment. Especially for gynogenetic fish with a longer sexual maturity time, the breeding cycle is long and there are many uncontrollable factors in the process. The preparation of ordinary all-male fish usually requires a series of processes such as "sex reversal - gynogenesis - supermale fish - all-male fish", which has a longer preparation cycle and more uncontrollable factors compared to the preparation of all-female fish populations. How to avoid the above risks and quickly cultivate all-male / all-female populations is a current research hotspot in aquaculture.

[0003] For a long time, the main research object of fish parthenogenetic breeding has been diploids, and there has been little research on polyploids, especially tetraploid fish. The main reason is that it is extremely difficult to artificially cultivate amphimictic and genetically stable tetraploids. The preparation of tetraploid fish has always been a hot and difficult point in the domestic and foreign aquaculture fields. At present, there are many reports on the preparation of tetraploid fish by physical and chemical methods, such as tetraploid rainbow trout, tetraploid blunt snout bream, tetraploid Japanese flounder, etc. However, the tetraploid fish prepared by these methods have not formed stable strains. In addition, biological methods such as distant hybridization are considered to be effective methods for creating amphimictic and genetically stable tetraploid fish strains, such as the creation of allopolyploid crucian carp and carp strains, autotetraploid crucian carp strains and other tetraploid fish. On the basis of the creation of these tetraploid fish, genetic improvement can be carried out on them by means of gynogenesis and androgenesis techniques. The improved tetraploid fish have obvious advantages in aspects such as sperm production, egg-bearing capacity, and stress resistance. Fertile tetraploid fish, especially male tetraploid fish, can produce relatively more diploid gametes and are more valuable in production applications. At present, there are very few reports on all-male tetraploid fish, and there is no successful case of successfully mass-cultivating an all-male tetraploid fish population in the existing technology. The reason is that there are few available diploid gametes. Common diploid economic fish usually produce haploid gametes, and the embryo after fertilization is diploid. If techniques such as inhibiting the first cleavage are used to double the chromosome number of the diploid embryo, it is extremely difficult to obtain viable tetraploid offspring, and it cannot be guaranteed whether it is a single sex. It is necessary to use hormones or temperature control and other methods for cultivation later to possibly obtain a single-sex population, but these operations have too long a cycle and too high a risk. This application effectively avoids the above risks, makes full use of the existing diploid gamete resources, and can directly obtain a large number of all-male tetraploid fish populations without chromosome doubling treatment, hormone feeding, or temperature control treatment, which well solves the technical difficulties faced by those skilled in the art. Summary of the Invention

[0004] The present invention provides a method for cultivating all-male tetraploid crucian carp, and its purpose is to fill the gap in the cultivation plan of male tetraploid fish.

[0005] In order to achieve the above purpose, the present invention provides a method for cultivating all-male tetraploid crucian carp, including the following steps:

[0006] Using gynogenetic autodiploid crucian carp as the female parent and androgenetic autodiploid crucian carp as the male parent for artificial induced spawning; wherein, the karyotype of the gynogenetic autodiploid crucian carp is XX, producing undiminished diploid eggs, and its gamete type is XX. Among the androgenetic autodiploid crucian carp, the karyotype of male individuals is XY or YY, producing undiminished diploid sperm, and its gamete type is XY or YY;

[0007] Artificially inseminate the above-mentioned non-reducing diploid eggs and non-reducing diploid sperm, incubate the obtained fertilized eggs, and culture them until sexual maturity. The surviving offspring are all-male tetraploid crucian carp populations, and their sex chromosome karyotypes are XXXY or XXYY.

[0008] Preferably, the gynogenetic autodiploid crucian carp is developed from the autotetraploid crucian carp by gynogenesis, is an all-female population, has a somatic chromosome number of 100, and can stably produce non-reducing diploid eggs with a chromosome number of 100.

[0009] Preferably, the androgenetic autodiploid crucian carp is developed from the autotetraploid crucian carp by androgenesis, has a somatic chromosome number of 100, and its male individuals can stably produce non-reducing diploid sperm with a chromosome number of 100.

[0010] Preferably, the artificial induced spawning includes injecting oxytocin into the female parent and the male parent.

[0011] Preferably, the artificial fertilization specifically includes the following steps:

[0012] S1. After the gynogenetic autodiploid crucian carp is in estrus, dry the fish body with a dry towel and squeeze out the eggs from the fish body, and place them in a basin that has been dried in advance;

[0013] S2. Squeeze the semen of the androgenetic autodiploid crucian carp into the basin in step S1, and stir and mix evenly with a dry feather to make it fertilized.

[0014] More preferably, in step S1, select gynogenetic autodiploid crucian carp with healthy signs and good gonadal development. The genomes of both the gynogenetic autodiploid crucian carp and the androgenetic autodiploid crucian carp are derived from the autotetraploid crucian carp, and the genomes of the hybrid offspring have better compatibility during the fusion process, which is beneficial to improving the hatching rate.

[0015] Preferably, the incubation specifically includes: spreading the fertilized eggs evenly in a culture dish filled with clean water and incubating them in still water at room temperature; the culture specifically includes: after hatching the fry, transfer the obtained fry to a plastic basin and continue to culture for 2-4 days, and transfer them to a pre-fertilized pond for feeding until sexual maturity after the fry develop a hump on their backs.

[0016] Preferably, the sexual maturity time is 105-130 days old, the hatching rate is 69.5-80%, and the survival rate is 65-70%.

[0017] More preferably, the sexual maturity time is 120 days old.

[0018] During the breeding and detection process, the all-male tetraploid crucian carp cultivated in this application exhibits the improved characteristic of significantly and stably shortening the sexual maturity time. When detected at 120 days of feeding, the fry have basically reached sexual maturity, significantly improving the breeding efficiency.

[0019] Preferably, after the fry are raised to sexual maturity, the cultivation method further includes performing ploidy detection and sex detection on the surviving offspring.

[0020] Preferably, the ploidy detection specifically includes: using flow cytometry DNA content detection method and / or kidney tissue lymphocyte chromosome ploidy detection method. The average DNA content of the somatic cells of the surviving offspring is between 190 and 215, and the number of somatic cell chromosomes is 200, that is, the surviving offspring are tetraploids.

[0021] Preferably, the sex detection specifically includes at least one of the following two schemes:

[0022] Scheme 1: Directly extrude white semen from sexually mature individuals to determine as male;

[0023] Scheme 2: Conduct anatomical experiments on sexually mature populations, and those with obvious testis tissues are determined as male.

[0024] Preferably, use flow cytometry DNA content detection method to detect the semen obtained from the sex detection. By the average DNA content of the semen being between 90 and 110, it can be determined that the sperm of the all-male tetraploid crucian carp population is diploid.

[0025] The above-mentioned scheme of the present invention has the following beneficial effects:

[0026] (1) Based on the characteristics that both gynogenetic homologous diploid crucian carp and androgenetic homologous diploid crucian carp produce unreduced gametes, the present invention makes full use of this excellent germplasm resource, performs artificial insemination on the two, realizes the large-scale preparation of all-male tetraploid crucian carp, and innovates the method for large-scale preparation of tetraploid fish; and selects male and female parents whose genomes all originate from homologous tetraploid crucian carp, which has better compatibility and is beneficial to improving the hatching rate and survival rate;

[0027] (2) Ordinary male homologous tetraploid crucian carp need one year to reach sexual maturity, but the all-male tetraploid crucian carp obtained by the cultivation method of the present invention reaches sexual maturity at only 120 days old, can stably produce diploid sperm, the reproductive performance is improved, and the breeding cycle is significantly shortened;

[0028] (3) All-male tetraploid crucian carp is an important germplasm resource for producing triploids, and can provide sufficient diploid gamete resources for large-scale preparation of high-quality triploid fish. The present invention has important theoretical and production significance in aspects such as research on fish sex determination genetic mechanism, sex-controlled breeding, and large-scale breeding of polyploid fish.

[0029] Other beneficial effects of the present invention will be described in detail in the subsequent specific implementation part. Brief Description of the Drawings

[0030] Figure 1 It is the cultivation flow chart of all-male tetraploid crucian carp in Examples 1-3;

[0031] Figure 2 It is the average DNA content and chromosome map of blood cells of all-male tetraploid crucian carp in Example 1;

[0032] Figure 3 It is the external shape of the testis and the histological map of the testis of all-male tetraploid crucian carp in Example 1;

[0033] Figure 4 It is the average DNA content map of the semen of all-male tetraploid crucian carp in Example 1. Specific implementation manners

[0034] To make the technical problems, technical solutions and advantages to be solved by the present invention clearer, the following will be described in detail with reference to the accompanying drawings and specific embodiments. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0035] In the description of the present invention, it should be noted that the orientation or positional relationship indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. is based on the orientation or positional relationship shown in the accompanying drawings. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation to the present invention. In addition, the terms "first", "second", "third" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0036] In the description of the present invention, it should be noted that unless otherwise clearly defined and limited, the terms "installed", "connected", "connected" should be understood in a broad sense. For example, it can be a locking connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected, or indirectly connected through an intermediate medium, and it can be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

[0037] In addition, the technical features involved in different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0038] Example 1:

[0039] This example provides a cultivation method for all-male tetraploid crucian carp. The cultivation flow chart of all-male tetraploid crucian carp is as Figure 1As shown in the figure. From March 2022 to July 2022, three batches of experiments on cultivating all-male tetraploid crucian carp were carried out in the Xuefengshan fish breeding valley in Shaoyang City, Hunan Province. The total duration of the experiment was 5 months.

[0040] The cultivation of each batch of all-male tetraploid crucian carp specifically includes the following steps:

[0041] (1) Artificial induced spawning and fertilization: During the breeding season, 10 female gynogenetic homologous diploid crucian carp and 10 male androgenetic homologous diploid crucian carp with healthy physical signs and well-developed gonads were selected and injected with a mixed inducing agent of chorionic gonadotropin (HCG) 400 - 600 IU / kg, luteinizing hormone releasing hormone analogue (LRH-A) 6 - 8 μg / kg, and domperidone maleate (DOM) 1 mg / kg for artificial induced spawning. The injection dose for male individuals was half of that for females; after the female gynogenetic homologous diploid crucian carp was in estrus, the fish body was dried with a dry towel and the eggs were squeezed out of the fish body and placed in a pre-dried basin. Then, the semen of the androgenetic homologous diploid crucian carp was squeezed in and stirred evenly with a dry feather to make it fertilized.

[0042] (2) Incubation and rearing: The fertilized eggs were evenly spread out in a culture dish filled with clean water and hatched in still water at room temperature. After hatching, more than 20,000 seedlings obtained were transferred to a plastic basin for continuous cultivation for 2 - 4 days. The average hatching rate of the three batches was about 74.36%. After the fry showed the waist spot, they were transferred to a pre-fertilized pond for rearing until they reached sexual maturity at 120 days old. The surviving offspring were a 100% all-male tetraploid crucian carp population, and the average survival rate of the three batches was about 67.06%. The specific hatching situation is shown in Table 1:

[0043] Table 1 Seedling cultivation situation of Example 1

[0044]

[0045] (3) Detection of ploidy and sex of offspring: The ploidy and gonad development of the offspring reared to 120 days old were detected; using the flow cytometry DNA content detection method and the lymphocyte chromosome ploidy detection method of kidney tissue, the detection results are as Figure 2 shown. The average DNA content of the somatic cells of the surviving offspring was 204.02, and the number of somatic cell chromosomes was 200, that is, the surviving offspring were tetraploid. Figure 2 Peak 2 in it is the interval where the average DNA content of the somatic cells detected by loading samples is the most concentrated and the number is the largest, and it can be judged as the average DNA content of the sample; although corresponding data were read for Peak 1, it may be a fragmented DNA sample, etc., and cannot be used as a representative of the average DNA content of the sample; the corresponding data read for Peak 3 are the somatic cells that are undergoing mitosis, and their DNA content is in a doubled state.

[0046] The sexually mature individuals were directly extruded to obtain white semen, which was determined to be male. Or anatomical experiments were conducted on sexually mature populations, and those with obvious testis tissues were determined to be male. After detecting all the surviving individuals, they were all male; the external appearance of the testis and the histological diagram of the testis of all-male tetraploid crucian carp are as shown in Figure 3 as follows.

[0047] The semen obtained from the sex detection was detected by flow cytometry DNA content detection method, and the sperm of the all-male tetraploid crucian carp population was determined to be diploid by the average DNA content of the semen; the average DNA content diagram of the semen of all-male tetraploid crucian carp is as shown in Figure 4 as follows, and the specific value is 101.60 shown by peak 1. The average DNA content of its semen is about half of the average DNA content of somatic cells ( Figure 2 ). Therefore, it can be determined that the sperm produced by the all-male tetraploid crucian carp population is diploid.

[0048] Figure 4 Peak 1 in

[0049] is the interval where the average DNA content in the semen for sample detection is most concentrated and the number is the largest, which can represent the average DNA content of the semen of all-male tetraploid crucian carp. The 199.57 shown by peak 2 may be that the sperm cells in the semen are in different developmental stages and their DNA content is in a doubled state, or it may be that a small number of somatic cells are taken out (contaminated) during the process of taking semen samples.

[0049] Through the above detection, it can be determined that the hybrid offspring of gynogenetic homologous diploid crucian carp and androgenetic homologous diploid crucian carp are 100% male tetraploids, which can reach sexual maturity at 120 days of age and can stably produce diploid sperm.

[0050] Example 2:

[0051] This example provides a method for cultivating all-male tetraploid crucian carp. The cultivation flow chart of all-male tetraploid crucian carp is as shown in Figure 1 as follows. From March 2023 to July 2023, three batches of cultivation experiments of all-male tetraploid crucian carp were carried out in Xuefeng Mountain Fish Seed Reproduction Valley, Shaoyang City, Hunan Province. The total duration of the experiment was 5 months.

[0052] The specific cultivation of each batch of all-male tetraploid crucian carp includes the following steps:

[0053] (1) Artificial induction of spawning and fertilization: During the breeding season, select 10 female gynogenetic autodiploid crucian carps and 10 male androgenetic autodiploid crucian carps with healthy physical signs and well-developed gonads. Inject a mixed oxytocic agent containing chorionic gonadotropin (HCG) at 400 - 600 IU / kg, luteinizing hormone releasing hormone analogue (LRH-A) at 6 - 8 μg / kg, and domperidone maleate (DOM) at 1 mg / kg for artificial induction of spawning. The injection dose for male individuals is half of that for females. After the female gynogenetic autodiploid crucian carp shows estrus, dry the fish body with a dry towel, squeeze out the eggs from the fish body, place them in a pre-dried basin, squeeze in the semen of the androgenetic autodiploid crucian carp, and stir evenly with a dry feather to make them fertilized.

[0054] (2) Incubation and rearing: Spread the fertilized eggs evenly in a culture dish filled with clean water and incubate them in still water at room temperature. After hatching, transfer more than 10,000 seedlings obtained to a plastic basin for continued cultivation for 2 - 4 days. The average hatching rate of the three batches is about 73.42%. After the fry show the waist spot, transfer them to a pre-fertilized pond for rearing until they reach sexual maturity at 120 days old. The surviving offspring are a 100% all-male tetraploid crucian carp population, and the average survival rate of the three batches is about 68.04%. The specific hatching situation is shown in Table 2:

[0055] Table 2 Seedling cultivation situation in Example 2

[0056]

[0057] (3) Detection of ploidy and sex of offspring: Detect the ploidy and gonadal development of the offspring reared to 120 days old; use flow cytometry DNA content detection method and kidney tissue lymphocyte chromosome ploidy detection method. The average DNA content of somatic cells in the surviving offspring is between 190 - 215, and the number of somatic cell chromosomes is 200, that is, the surviving offspring are tetraploids.

[0058] Squeeze out the white semen directly from the sexually mature individuals to determine them as male, or conduct dissection experiments on the sexually mature population. Those with obvious testis tissue are determined as male. After detecting all the surviving individuals, all are male.

[0059] Use the flow cytometry DNA content detection method to detect the semen obtained from the sex detection. Determine that the sperm of the all-male tetraploid crucian carp population is diploid through the average DNA content of the semen; the average DNA content of the semen of the all-male tetraploid crucian carp is between 90 - 110, and the average DNA content of its semen is about half of the average DNA content of somatic cells. Therefore, it can be determined that the sperm produced by the all-male tetraploid crucian carp population is diploid. Through the above detections, it can be determined that the hybrid offspring of female gynogenetic autodiploid crucian carp and male androgenetic autodiploid crucian carp are 100% male tetraploids, can reach sexual maturity at 120 days old, and can stably produce diploid sperm.

[0060] Example 3:

[0061] This example provides a method for cultivating all-male tetraploid crucian carp. The cultivation flow chart of all-male tetraploid crucian carp is as Figure 1 shown. From April 2024 to August 2024, three batches of cultivation experiments of all-male tetraploid crucian carp were carried out in Xuefengshan Fish Breeding Valley, Shaoyang City, Hunan Province. The total duration of the experiment was 5 months.

[0062] The specific cultivation of each batch of all-male tetraploid crucian carp includes the following steps:

[0063] (1) Artificial induced spawning and fertilization: During the breeding season, 10 female gynogenetic autodiploid crucian carp and 10 male androgenetic autodiploid crucian carp with healthy physical signs and well-developed gonads were selected, and a mixed inducing agent of chorionic gonadotropin (HCG) 400 - 600 IU / kg, luteinizing hormone releasing hormone analogue (LRH-A) 6 - 8 μg / kg and domperidone maleate (DOM) 1 mg / kg was injected for artificial induced spawning. The injection dose of male individuals was half of that of females; after the female gynogenetic autodiploid crucian carp was in estrus, the fish body was dried with a dry towel and the eggs were extruded from the fish body, placed in a pre-dried basin, the semen of androgenetic autodiploid crucian carp was squeezed in, and stirred evenly with a dry feather to make it fertilized.

[0064] (2) Incubation and rearing: The fertilized eggs were evenly spread out in a culture dish filled with clean water and hatched in still water at room temperature. More than 10,000 seedlings obtained after hatching were transferred to a plastic basin for continued cultivation for 2 - 4 days. The average hatching rate of the three batches was about 74.10%. After the fry showed swim bladders, they were transferred to a pre-fertilized pond for rearing until they reached sexual maturity at 120 days old. The surviving offspring were a 100% all-male tetraploid crucian carp population, and the average survival rate of the three batches was about 68.47%. The specific hatching situation is shown in Table 3:

[0065] Table 3 Seedling Cultivation Situation of Example 3

[0066]

[0067] (3) Detection of ploidy and sex of offspring: The ploidy and gonadal development of the offspring reared to 120 days old were detected; using flow cytometry DNA content detection method and kidney tissue lymphocyte chromosome ploidy detection method, it was detected that the average DNA content of somatic cells of the surviving offspring was between 190 - 215, and the somatic cell chromosome number was 200, that is, the surviving offspring were tetraploid.

[0068] The mature individuals were directly extruded with white semen to be determined as male, or anatomical experiments were carried out on the mature population, and those with obvious testis tissues were determined as male. After detecting all the surviving individuals, all were male.

[0069] The semen obtained from the sex detection is detected by flow cytometry DNA content detection method, and the sperm of the all-male tetraploid crucian carp population is determined to be diploid by the average DNA content of the semen. The average DNA content of the semen of the all-male tetraploid crucian carp is between 90 and 110, and the average DNA content of its semen is about half of the average DNA content of somatic cells. Therefore, it can be determined that the sperm produced by the all-male tetraploid crucian carp population is diploid. Through the above detection, it can be determined that the hybrid offspring of the gynogenetic autodiploid crucian carp and the androgenetic autodiploid crucian carp is 100% male tetraploid, and it can reach sexual maturity at 120 days of age and can stably produce diploid sperm.

[0070] Generally speaking, the preparation of all-male tetraploid crucian carp by this method is a major breakthrough in the research of fish monosexual breeding. Compared with the method of preparing monosexual populations by techniques such as sex reversal, it can obtain monosexual varieties faster and also avoid the impact on the environment caused by feeding hormones during sex reversal. By utilizing the characteristics that both gynogenetic autodiploid crucian carp and androgenetic autodiploid crucian carp produce unreduced gametes, and crossing the two, a tetraploid crucian carp population can be prepared on a large scale, innovating the method for large-scale preparation of tetraploid fish. Moreover, compared with the ordinary male autotetraploid crucian carp, the sexual maturity time of this all-male tetraploid crucian carp population is significantly shortened and the reproductive performance is improved. The all-male tetraploid crucian carp is an important germplasm resource for producing triploids and can provide sufficient diploid gamete resources for large-scale preparation of high-quality triploid fish. These have important theoretical and production significance in aspects such as the research on the genetic mechanism of fish sex determination, sex control breeding, and large-scale breeding of polyploid fish.

[0071] The above is the preferred embodiment of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the principle of the present invention, several improvements and refinements can be made, and these improvements and refinements should also be regarded as the protection scope of the present invention.

Claims

1. A method for breeding all-male tetraploid crucian carp, characterized in that: The following steps are involved: Artificial induced spawning is performed with a gynogenetic homologous diploid crucian carp as the female parent and an androgenetic homologous diploid crucian carp as the male parent; wherein the sex chromosome karyotype of the gynogenetic homologous diploid crucian carp is XX, and it produces unreduced diploid eggs, whose gamete type is XX; the sex chromosome karyotype of the male individual in the androgenetic homologous diploid crucian carp is XY or YY, and it produces unreduced diploid sperm, whose gamete type is XY or YY; Artificial insemination is performed on the unreduced diploid eggs and unreduced diploid sperm, the fertilized eggs obtained are hatched, and cultured to sexual maturity. The surviving offspring are an all-male tetraploid crucian carp population with a sex chromosome karyotype of XXXY or XXYY.

2. The method according to claim 1, characterized in that: The gynogenetic homologous diploid crucian carp is developed from the gynogenetic nucleus of the autotetraploid crucian carp, is an all-female population, has 100 somatic cell chromosomes, and can stably produce unreduced diploid eggs with 100 chromosomes; the androgenetic homologous diploid crucian carp is developed from the androgenetic nucleus of the autotetraploid crucian carp, has 100 somatic cell chromosomes, and its male individuals can stably produce unreduced diploid sperm with 100 chromosomes.

3. The method according to claim 1, characterized in that The artificial induction of labor includes injecting oxytocin into the mother and the father.

4. The method according to claim 1, characterized in that: The artificial insemination specifically comprises the following steps: S1. After the gynogenetic homologous diploid crucian carp comes into estrus, dry the fish body with a dry towel and squeeze out the eggs from the fish body and place them in a basin that has been dried in advance; S2. Squeeze the semen of homologous diploid crucian carp with androgeny into the basin in step S1, and stir and mix with dry feathers to achieve fertilization.

5. The method according to claim 1, characterized in that The hatching specifically includes: spreading the fertilized eggs in a culture dish filled with clean water and incubating them in static water at room temperature; the culturing specifically includes: after hatching, transferring the obtained seedlings to a plastic basin for further culturing for 2-4 days, and transferring the seedlings to a pre-fertilized pond for breeding until they reach sexual maturity.

6. The method according to any one of claims 1 to 5, characterized in that: The sexual maturity time of the fry is 105-130 days old, the hatching rate is 69.5-80%, and the survival rate is 65-70%.

7. The method according to any one of claims 1 to 5, characterized in that: After the fry are raised to sexual maturity, the breeding method further comprises conducting ploidy detection and gender detection on the surviving offspring.

8. The method according to claim 7, characterized in that The ploidy detection specifically includes: using flow cytometry DNA content detection method and / or kidney tissue lymphocyte chromosome ploidy detection method, the average DNA content of somatic cells of the surviving offspring is between 190-215, and the number of somatic cell staining is 200, that is, the surviving offspring is tetraploid.

9. The method according to claim 7, characterized in that: The gender detection specifically includes at least one of the following two solutions: Option 1: directly squeeze out the white semen from a sexually mature individual and identify it as a male; Option 2: Conduct anatomical experiments on sexually mature groups, and identify those with obvious testicular tissue as males.

10. The method according to claim 9, characterized in that The semen obtained by the sex detection is detected by flow cytometry DNA content detection method. The average DNA content of the semen is between 90-110, which can determine that the sperm of the all-male tetraploid crucian carp population is diploid.

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