A method for cultivating a new strain of fast-growing high-temperature-resistant hybrid triploid oysters

Abstract

The present application firstly obtains the diploid Fujian oyster common, shell gold and shell black strains with fast growth and pure shell color through population breeding. Secondly, the tetraploid Fujian oyster common, shell gold and shell black strains with high and stable tetraploid rate and stable shell color inheritance are obtained through ploidy breeding. Then, the tetraploid populations of long oyster 'Haida 1', 'Haida 2' and 'Haida 3' are obtained by using ploidy breeding technology with the pure shell color, shell type and large size of the individuals as parents. Finally, the fast-growing and high-temperature-resistant hybrid triploid oyster new strains with different shell colors are obtained through interspecific hybridization. The hybrid triploid oyster new strains obtained in the present application maintain the fast growth and strong stress resistance of long oyster, and have the excellent high-temperature-resistant traits of Fujian oyster. In addition, the shell color of the gold and black hybrid triploid oyster new strains is pure and the color is beautiful. The hybrid triploid oyster new strains obtained in the present application expand the germplasm resources of the shell color strains of the cultured oyster, provide important germplasm resources for the high-quality development and transformation and upgrading of the oyster industry to the high-end consumer market, and have a broad industrial application prospect.

Description

Technical Field

[0002] This invention belongs to the field of shellfish breeding technology, specifically relating to a method for cultivating a new fast-growing, heat-resistant hybrid triploid oyster strain. Background Technology

[0004] As an important economic shellfish, oysters are widely farmed in my country. Over the past decade, farmed oyster production has increased from 3.94 million tons in 2011 to 6.67 million tons in 2023, a growth of nearly 69%. In recent years, triploid breeding has received increasing attention. Due to the sterility of triploids, gamete development is inhibited. Therefore, during the summer, the energy used for gamete production can be used to maintain growth and development, thus preserving their excellent growth characteristics and ensuring a normal market supply during the summer.

[0005] Fujian oysters and Pacific oysters, as the two most productive economic shellfish in my country, have already achieved triploid industrialization. However, the traditional methods of obtaining Fujian oyster homologous triploids by hybridizing tetraploid and diploid Fujian oysters, and Pacific oyster homologous triploids by hybridizing tetraploid and diploid Pacific oysters, while producing fast-growing Pacific oyster homologous triploids, have resulted in poor adaptation to high summer temperatures. Meanwhile, Fujian oyster homologous triploids exhibit spawning during hot summer months, severely hindering the healthy development of the oyster farming industry. Through genetic improvement of diploid and tetraploid oyster parents, followed by ploidy breeding and interspecific hybridization, it is hoped that the rapid growth characteristics of Pacific oysters and the heat tolerance of Fujian oysters can be combined to cultivate a new fast-growing, heat-resistant hybrid triploid oyster variety.

[0006] Shell color, as a natural marker, can determine whether there is cross-contamination from wild germplasm or other strains during breeding. This feature simplifies strain management, ensures the accuracy and efficiency of genetic improvement, and improves strain purity. On the other hand, cultivating brightly colored oyster varieties can also enrich oyster germplasm resources, meet the diverse needs of the market and consumers, further increase their added value, and enhance the economic benefits of the oyster industry. Summary of the Invention

[0008] To overcome the defects and shortcomings of the traditional homologous triploid oysters in my country described in the background art, this invention develops a cultivation method for a new fast-growing, high-temperature resistant hybrid triploid oyster strain.

[0009] A method for cultivating a new fast-growing, heat-resistant hybrid triploid oyster strain, characterized by the following steps:

[0010] a. Using the diploid 'Haida No. 1' (GS-01-005-2013) oyster as the base population, triploid 'Haida No. 1' oysters were induced to form a base population. Using the triploid 'Haida No. 1' oysters as the female parent and the diploid 'Haida No. 1' oysters as the male parent, tetraploid 'Haida No. 1' oysters were induced to form a base population. After two generations of population selection, tetraploid 'Haida No. 1' oysters were obtained.

[0011] b. Using the diploid of the new Pacific oyster variety "Haida No. 2" (GS-01-007-2016) as the base population, triploid Pacific oysters "Haida No. 2" were induced to form a base population. Using the triploid Pacific oyster "Haida No. 2" as the female parent and the diploid Pacific oyster "Haida No. 2" as the male parent, a tetraploid Pacific oyster "Haida No. 2" was induced to form a base population. After four generations of population selection, the tetraploid Pacific oyster "Haida No. 2" was obtained.

[0012] c. Using the diploid 'Haida No. 3' (GS-01-007-2018) oyster as the base population, triploid 'Haida No. 3' oysters were induced to form a base population. Using the triploid 'Haida No. 3' oysters as the female parent and the diploid 'Haida No. 3' oysters as the male parent, tetraploid 'Haida No. 3' oysters were induced to form a base population. Through four generations of population selection, tetraploid 'Haida No. 3' oysters were obtained.

[0013] d. Select diploid Fujian oysters with common shell color, gold and black as parents, and obtain diploid Fujian oyster strains with common shell, gold shell and black shell through two consecutive generations of population selection;

[0014] e. Using the diploid Fujian oyster common shell color strain as the base population, induce the production of the triploid Fujian oyster common shell color strain. Using the triploid Fujian oyster common shell color strain as the female parent and the diploid Fujian oyster common shell color strain as the male parent, induce the production of the tetraploid Fujian oyster common shell color strain as the base population. Through two consecutive generations of population selection, obtain the tetraploid Fujian oyster common shell color strain.

[0015] f. Using the diploid Fujian oyster shell gold line as the base population, induce the formation of the triploid Fujian oyster shell gold line. Using the triploid Fujian oyster shell gold line as the female parent and the diploid Fujian oyster shell gold line as the male parent, induce the formation of the tetraploid Fujian oyster shell gold line as the base population. Select and breed the population for two consecutive generations to obtain the tetraploid Fujian oyster shell gold line.

[0016] g. Using the diploid Fujian oyster shell black strain as the base population, induce the formation of the triploid Fujian oyster shell black strain. Using the triploid Fujian oyster shell black strain as the female parent and the diploid Fujian oyster shell black strain as the male parent, induce the formation of the tetraploid Fujian oyster shell black strain as the base population. After two consecutive generations of population selection, obtain the tetraploid Fujian oyster shell black strain.

[0017] h. Using the diploid Fujian oyster common, golden-shelled, and black-shelled varieties described in step (d) as the female parent, and the tetraploid Pacific oyster “Haida No. 1,” “Haida No. 2,” and “Haida No. 3” described in steps (a), (b), and (c) as the male parent, hybridization can yield new Fujian-Pacific hybrid triploid varieties with three shell colors; using Pacific oyster “Haida No. 1,” “Haida No. 2,” and “Haida No. 4” as the female parent, and the tetraploid Fujian oyster common, golden-shelled, and black-shelled varieties described in steps (e), (f), and (g) as the male parent, hybridization can yield new Fujian-Pacific hybrid triploid varieties with three shell colors.

[0018] Furthermore, in steps (a), (b), (c), (e), (f), and (g), triploid Crassostrea gigas oysters “Haida No. 1,” “Haida No. 2,” and “Haida No. 3” are induced, as are triploid Crassostrea gigas common, shell gold, and shell black strains. After fertilization for 15 minutes, 0.75 mg / L of cytochalasin B is added and treated for another 15 minutes. Then, the eggs are washed with 2 mg / L dimethyl sulfoxide solution. The groups with a ploidy retention rate of over 95% in the larvae are selected. The larvae are then raised and the adult oysters are grown using conventional methods, thus obtaining the triploid induced groups of the above six strains.

[0019] Furthermore, in steps (a), (b), (c), (e), (f), and (g), tetraploid oysters “Haida No. 1,” “Haida No. 2,” and “Haida No. 3” are induced, as are tetraploid Fujian oysters of common, golden, and black shell varieties. After fertilization for 8-10 minutes, 1 mg / L of cytochalasin B is added and the treatment is continued for 8-10 minutes. The tetraploid induced groups of the above six varieties are obtained when the ploidy retention rate of larvae is above 80%.

[0020] Furthermore, in steps (a), (b), (c), (e), (f), and (g), when conducting population selection for the above six tetraploid strains, individuals with the top 10% shell height and total weight are selected, and more than 100 males and 100 females are selected in each generation, and high-intensity selection is carried out for 2 to 4 generations.

[0021] Furthermore, in step (d), when selecting and breeding the above-mentioned diploid Fujian oyster common, golden-shelled and black-shelled strains, oysters with good vitality, beautiful shell shape and no damage and pure shell color are selected as parent oysters, and the top 10% of individuals in shell height and wet weight are selected and continuously intensively selected for 2 to 3 generations.

[0022] Furthermore, in step (h), individuals with uniform development, ≥15 million eggs, deep yolk color, and pure shell color are selected from different diploid populations as maternal parents, and individuals with pure shell color and vigorous sperm motility are selected from different tetraploid populations as paternal parents. By using conventional methods for larval rearing and adult oyster cultivation, a new fast-growing, heat-resistant hybrid triploid oyster strain can be obtained.

[0023] Beneficial effects of the present invention

[0024] The technical solution provided by this invention has the following advantages compared with known technologies.

[0025] (1) After more than ten generations of family and population selection, the new varieties of Pacific oyster “Haida No. 1”, “Haida No. 2” and “Haida No. 3” have accumulated a large amount of additive genetic variation. Through ploidy breeding, corresponding tetraploid populations were obtained. Both tetraploid and diploid populations have the characteristics of rapid growth, strong resistance, and rich shell color. (2) Through population selection, three diploid strains of Fujian oyster with rich shell color (ordinary, golden and black) and stable genetics and improved growth traits were obtained. Through ploidy breeding, ordinary, golden and black tetraploid improved strains of Fujian oyster were obtained, enriching the tetraploid germplasm resources of Fujian oyster. (3) Through ploidy breeding and interspecific hybridization, a new strain of fast-growing and heat-resistant hybrid triploid oyster was cultivated. The offspring maintain the rapid growth and strong resistance of Pacific oyster while also maintaining the heat resistance of Fujian oyster. It has broad prospects for industrial application. Meanwhile, the newly cultivated golden and black hybrid triploid oyster strains also exhibit noble colors, providing a possibility for promoting my country's oyster industry to the high-end consumer market. Attached Figure Description

[0027] Figure 1 This is a technical roadmap for the cultivation method of a new fast-growing, high-temperature resistant hybrid triploid oyster strain according to the present invention. Detailed Implementation

[0028] The present invention will be further illustrated by specific embodiments below, but these are not intended to limit the invention.

[0029] I. Breeding of new triploid oyster strains with common shell color

[0030] (1) Cultivation of the tetraploid strain of the Pacific oyster “Haida No. 1”

[0031] a. Select 500 large and aesthetically pleasing Pacific oysters ("Haida No. 1"), dissect and distinguish their sexes. Select 50 individuals with well-developed eggs, ≥20 million eggs, and dark yolk color as maternal parents, and select 50 individuals with full gonads and vigorous sperm motility as paternal parents. After fertilization for 15 minutes, add 0.75 mg / L of cytochalasin B and continue treatment for 15 minutes. Soak the eggs in 2 mg / L dimethyl sulfoxide solution and wash them with filtered seawater. Use flow cytometry to detect larval ploidy. Retain the treatment group with a triploid rate of over 95%. Use conventional methods to cultivate larvae and raise juveniles to obtain the triploid induced group of Pacific oyster "Haida No. 1".

[0032] b. Select 50 oysters from the triploid induction group of Crassula 'Haida No. 1' as the female parent and 50 oysters from Crassula 'Haida No. 1' as the male parent. After fertilization for 10-15 minutes, add 1 mg / L of cytochalasin B and continue treatment for 8-10 minutes. For the treatment group where the ploidy retention rate of larvae is above 80%, carry out larval cultivation and juvenile rearing using conventional methods to obtain the triploid induction group of Crassula 'Haida No. 1'.

[0033] c. Using the tetraploid "Haida No. 1" oyster with beautiful shell shape and large size as the parent, with a selection pressure of 10%, 200 tetraploid "Haida No. 1" oysters are selected from each generation. After 2-3 generations of high-intensity population selection, the tetraploid strain of "Haida No. 1" oyster (NGGGG) is obtained.

[0034] (2) Cultivation of diploid Fujian oyster common shell color strain

[0035] Five thousand diploid Fujian oysters were collected from Putian, Fujian. Based on shell height and wet weight as target traits, 50 females and 50 males with the largest shell height and wet weight were selected as parents with a selection intensity of 1.7 to construct a common shell color strain of diploid Fujian oysters. Subsequently, the same method was used to carry out population selection for 2 to 3 consecutive generations to obtain the common shell color breeding strain of diploid Fujian oysters (NAA).

[0036] (3) Cultivation of tetraploid Fujian oyster strains with common shell color

[0037] a. Select 500 large, aesthetically pleasing diploid Fujian oysters with common shell color. Dissect and distinguish between males and females. Select 50 individuals with well-developed eggs, ≥20 million eggs, and dark yolk color as females. Select 50 individuals with full gonads and vigorous sperm motility as males. After fertilization for 15 minutes, add 0.75 mg / L of cytochalasin B and continue treatment for 15 minutes. Soak in 2 mg / L dimethyl sulfoxide solution and wash with filtered seawater. Use flow cytometry to detect larval ploidy. Retain the treatment group with a triploid rate of over 95%. Use conventional methods to cultivate larvae and raise juveniles to obtain the triploid Fujian oyster common shell color induction group.

[0038] b. Select 50 oysters from the triploid Fujian oyster common shell color induction group as the female parent, and select 50 oysters from the diploid Fujian oyster common shell color breeding line as the male parent. After fertilization for 10-15 minutes, add 1 mg / L of cytochalasin B and continue treatment for 8-10 minutes. The treatment group with a ploidy retention rate of more than 80% of the larvae was tested. The larvae were cultured and the juveniles were raised using conventional methods to obtain the tetraploid Fujian oyster common shell color induction group.

[0039] c. Using tetraploid Fujian oysters with beautiful shell shape and large size as parents, 200 tetraploid Fujian oysters with common shell color are selected from each generation with a 10% selection pressure. After 2-3 generations of continuous high-intensity population selection, a tetraploid Fujian oyster common shell color breeding line (NAAAA) is obtained.

[0040] (4) Breeding of new triploid oyster strains with common shell color

[0041] Fifty individuals with full gonads and high sperm motility were selected from the tetraploid strain "Haida No. 1" (NGGGG) of the Pacific oyster as paternal parents. Thirty individuals with uniformly developed eggs, ≥20 million eggs, and deep yolk color were selected from the common shell color breeding line of the diploid Fujian oyster (NAA) as maternal parents. Hybridization yielded a new common shell color, fast-growing, heat-resistant Fujian-Pacific hybrid triploid oyster strain (NAGG). The common shell color breeding line of the tetraploid Fujian oyster (NAAAA) was also selected. Fifty individuals with full gonads and vigorous sperm motility were selected from the oysters to serve as the male parent, and 300 individuals with uniformly developed eggs, ≥20 million eggs, and dark yolk color were selected from the Pacific oyster “Haida No. 1” (NGG) to serve as the female parent. By hybridization, a new triploid oyster strain with ordinary shell color, fast growth, and high temperature resistance (NGAA) can be obtained. At the same time, a triploid control group of Pacific oyster “Haida No. 1” (NGGG) and a triploid Fujian oyster ordinary shell color control group (NAAA) were constructed.

[0042] II. Cultivation of New Golden-Shelled Hybrid Triploid Oyster Strains

[0043] (1) Cultivation of the tetraploid strain of the Pacific oyster “Haida No. 2”

[0044] a. Select 500 large and aesthetically pleasing Pacific oysters ("Haida No. 2"), dissect and distinguish their sexes. Select 50 individuals with well-developed eggs, ≥20 million eggs, and dark yolk color as females, and 50 individuals with full gonads and vigorous sperm motility as males. After fertilization for 15 minutes, add 0.75 mg / L of cytochalasin B and continue treatment for 15 minutes. Soak the eggs in 2 mg / L dimethyl sulfoxide solution and wash them with filtered seawater. Use flow cytometry to detect larval ploidy. Retain the treatment group with a triploid rate of over 95%. Use conventional methods to cultivate larvae and raise juveniles to obtain the triploid induced group of Pacific oyster "Haida No. 2".

[0045] b. Select 50 oysters from the triploid induction group of Crassula 'Haida No. 2' as the female parent and 50 oysters from the triploid induction group of Crassula 'Haida No. 2' as the male parent. After fertilization for 10-15 minutes, add 1 mg / L of cytochalasin B and continue treatment for 8-10 minutes. For the treatment group where the ploidy retention rate of larvae is above 80%, carry out larval cultivation and juvenile rearing using conventional methods to obtain the triploid induction group of Crassula 'Haida No. 2'.

[0046] c. Using the tetraploid 'Haida No. 2' oyster with beautiful shell shape and large size as the parent, with a selection pressure of 10%, 200 tetraploid 'Haida No. 2' oysters are selected from each generation. After 2-3 generations of continuous high-intensity population selection, the tetraploid strain of 'Haida No. 2' oyster (GGGGG) is obtained.

[0047] (2) Cultivation of diploid Fujian oyster shell gold strain

[0048] Five thousand diploid Fujian oysters with golden shells were collected from Putian, Fujian. Based on shell color, shell height, and wet weight as target traits, 50 females and 50 males with the largest shell height and wet weight, both with pure golden shells, were selected as parents with a selection intensity of 1.7 to construct a diploid Fujian oyster golden shell strain. Subsequently, the same method was used to conduct 2-3 generations of population selection to obtain the diploid Fujian oyster golden shell breeding line (GAA).

[0049] (3) Cultivation of tetraploid Fujian oyster shell gold strain

[0050] a. Select 500 large, aesthetically pleasing diploid Fujian oysters with golden shells. Dissect and distinguish between males and females. Select 50 individuals with well-developed eggs, ≥20 million eggs, and deep yolk color as females. Select 50 individuals with full gonads and vigorous sperm motility as males. After fertilization for 15 minutes, add 0.75 mg / L of cytochalasin B and continue treatment for 15 minutes. Soak in 2 mg / L dimethyl sulfoxide solution and wash with filtered seawater. Use flow cytometry to detect ploidy of larvae. Retain the treatment group with a triploid rate of over 95%. Use conventional methods to cultivate larvae and raise juveniles to obtain the triploid Fujian oyster golden shell strain induction group.

[0051] b. Select 50 oysters from the triploid Fujian oyster shell gold induction group as the female parent and select 50 oysters from the diploid Fujian oyster shell gold breeding line as the male parent. After fertilization for 10-15 minutes, add 1 mg / L of cytochalasin B and continue treatment for 8-10 minutes. The treatment group with a ploidy retention rate of more than 80% of the larvae is tested. The larvae are cultured and the juveniles are raised using conventional methods to obtain the tetraploid Fujian oyster shell gold induction group.

[0052] c. Using tetraploid Fujian oysters with beautiful shells and large size and golden shell color as parents, 200 tetraploid Fujian oysters with golden shell color are selected from each generation with a 10% selection pressure. After 2-3 generations of high-intensity population selection, a tetraploid Fujian oyster golden shell color breeding line (GAAAA) is obtained.

[0053] (4) Cultivation of new golden-shelled hybrid triploid oyster strains

[0054] Fifty individuals with full gonads and high sperm motility were selected from the tetraploid strain "Haida No. 2" (GGGGG) of the Pacific oyster as male parents. Thirty individuals with uniformly developed eggs, ≥20 million eggs, and deep yolk color were selected from the diploid Fujian oyster golden shell breeding line (GAA) as female parents. Hybridization yields a new golden-shelled, fast-growing, heat-resistant Fujian Pacific oyster hybrid triploid strain (GAGG). A new strain was obtained from the tetraploid Fujian oyster golden shell breeding line (GAAAA). Fifty individuals with full gonads and vigorous sperm motility were selected as male parents, and 300 individuals with uniformly developed eggs, ≥20 million eggs, and deep yolk color were selected as female parents from the Pacific oyster “Haida 2” (GGG). By hybridization, a new golden-shelled, fast-growing, heat-resistant, long-term hybrid triploid oyster strain (GGAA) was obtained. At the same time, a triploid control group of Pacific oyster “Haida 2” (GGGG) and a triploid Fujian oyster golden-shell control group (GAAA) were constructed.

[0055] III. Cultivation of New Black-Shelled Triploid Oyster Strains

[0056] (1) Cultivation of the tetraploid strain of the Pacific oyster “Haida No. 3”

[0057] a. Select 500 large and aesthetically pleasing Pacific oysters ("Haida No. 3"), dissect and distinguish their sexes. Select 50 individuals with well-developed eggs, ≥20 million eggs, and dark yolk color as females, and 50 individuals with full gonads and vigorous sperm motility as males. After fertilization for 15 minutes, add 0.75 mg / L of cytochalasin B and continue treatment for 15 minutes. Soak the eggs in 2 mg / L dimethyl sulfoxide solution and wash them with filtered seawater. Use flow cytometry to detect larval ploidy. Retain the treatment group with a triploid rate of over 95%. Use conventional methods to cultivate larvae and raise juveniles to obtain the triploid induced group of Pacific oyster "Haida No. 3".

[0058] b. Select 50 oysters from the triploid induction group of Crassula 'Haida No. 3' as the female parent and 50 oysters from the triploid induction group of Crassula 'Haida No. 3' as the male parent. After fertilization for 10-15 minutes, add 1 mg / L of cytochalasin B and continue treatment for 8-10 minutes. For the treatment group where the ploidy retention rate of larvae is above 80%, carry out larval cultivation and juvenile rearing using conventional methods to obtain the triploid induction group of Crassula 'Haida No. 3'.

[0059] c. Using the tetraploid 'Haida No. 3' oyster with beautiful shell shape and large size as the parent, 200 tetraploid 'Haida No. 3' oysters were selected from each generation with a 10% selection pressure. After 2-3 generations of continuous high-intensity population selection, the tetraploid strain of 'Haida No. 3' oyster (BGGGG) was obtained.

[0060] (2) Cultivation of diploid Fujian oyster black-shelled strain

[0061] a. Five thousand diploid Fujian oysters with black shells were collected from Putian, Fujian. Using shell color, shell height, and wet weight as target traits, 50 females and 50 males with the highest shell height and wet weight (both shells being pure black) were selected as parents at a selection intensity of 1.7 to construct a diploid Fujian oyster black-shelled strain. Subsequently, this process was repeated for 2-3 generations to obtain the diploid Fujian oyster black-shelled breeding line (BAA).

[0062] (3) Cultivation of tetraploid Fujian oyster black-shelled strain

[0063] a. Select 500 large, aesthetically pleasing diploid Fujian oysters with black shells. Dissect and distinguish between males and females. Select 50 individuals with well-developed eggs, ≥20 million eggs, and dark yolk color as females. Select 50 individuals with full gonads and vigorous sperm motility as males. After fertilization for 15 minutes, add 0.75 mg / L of cytochalasin B and continue treatment for 15 minutes. Soak in 2 mg / L dimethyl sulfoxide solution and wash with filtered seawater. Use flow cytometry to detect ploidy of larvae. Retain the treatment group with a triploid rate of over 95%. Use conventional methods to cultivate larvae and raise juveniles to obtain the triploid Fujian oyster black-shelled strain induction group.

[0064] b. Select 50 oysters from the triploid Fujian oyster shell black induction group as the female parent and select 50 oysters from the diploid Fujian oyster shell black breeding line as the male parent. After fertilization for 10-15 minutes, add 1 mg / L of cytochalasin B and continue treatment for 8-10 minutes. The treatment group with a ploidy retention rate of more than 80% of the larvae was tested. The larvae were cultured and the juveniles were raised using conventional methods to obtain the tetraploid Fujian oyster shell black strain induction group.

[0065] c. Using large, aesthetically pleasing tetraploid Fujian oysters with black shells as parents, and with a 10% selection pressure, 200 tetraploid Fujian oysters with black shells are selected from each generation. This process is repeated for 2-3 generations of high-intensity population selection to obtain the tetraploid Fujian oyster black-shelled breeding line (BAAAA).

[0066] (4) Cultivation of new black-shelled hybrid triploid oyster strains

[0067] Fifty individuals with full gonads and high sperm motility were selected from the tetraploid strain "Haida No. 3" (BGGGG) of the Pacific oyster as male parents. Thirty individuals with uniformly developed eggs, ≥20 million eggs, and deep yolk color were selected from the diploid Fujian oyster black-shelled breeding line (BAA) as female parents. Hybridization yielded a new black-shelled, fast-growing, heat-resistant Fujian Pacific oyster hybrid triploid strain (BAGG). A new strain was obtained from the tetraploid Fujian oyster black-shelled breeding line (BAAAA). Fifty individuals with full gonads and vigorous sperm motility were selected as male parents, and 300 individuals with uniformly developed eggs, ≥20 million eggs, and dark yolk color were selected as female parents from the Pacific oyster “Haida 3” (BGG). By hybridization, a new black-shelled, fast-growing, heat-resistant, long-term hybrid triploid oyster strain (BGAA) was obtained. At the same time, a triploid control group of Pacific oyster “Haida 3” (BGGG) and a triploid Fujian oyster black-shell control group (BAAA) were constructed.

[0068] The six new hybrid strains and six control groups obtained above were transferred to the main breeding sites in Rushan, Shandong for trial breeding. Statistical analysis showed that, compared with the control groups, the shell height of the hybrid groups increased by 23-36%, the wet weight increased by 26-42%, and the survival rate increased by 15-29%. The production data of each group are recorded in Table 1.

[0069] Table 1. Comparison of production performance between fast-growing, heat-resistant hybrid triploid oyster strains and the control group.

[0070] Shell height (mm) Wet weight (g) Survival rate (%) NGGG 25 24.17 56.15 NGGA 34.5 33.21 72.56 NAGG 37.06 35.26 75.18 NAAA 30.97 28.39 60.25 BGGG 33.29 30.51 40.95 BGGA 43.34 40.26 52.26 BAGG 39.54 39.56 55.26 BAAA 30.15 26.14 49.55 GGGG 31.81 25.65 47.56 GGGA 42.26 32.45 59.65 GAGG 41.88 33.98 65.26 GAAA 33.26 23.38 53.11

[0071] The above description is only used to illustrate the technical solutions and features of the present invention, and is not intended to limit the scope of protection of the present invention. Any simple modifications or equivalent substitutions made by those skilled in the art to the technical solutions of the present invention should fall within the scope of protection of the technical solutions of the present invention.

Claims

1. A method for breeding a new strain of fast-growing high-temperature-resistant hybrid triploid oysters, characterized in that, Includes the following steps: a. Using the diploid 'Haida No. 1' (GS-01-005-2013) Pacific oyster as the base population, triploid 'Haida No. 1' Pacific oysters were induced to form a base population. Using the triploid 'Haida No. 1' Pacific oysters as the female parent and the diploid 'Haida No. 1' Pacific oysters as the male parent, tetraploid 'Haida No. 1' Pacific oysters were induced to form a base population. After two generations of population selection, tetraploid 'Haida No. 1' Pacific oysters were obtained. b. Using the diploid 'Haida No. 2' (GS-01-007-2016) Pacific oyster as the base population, triploid 'Haida No. 2' Pacific oysters were induced to form a base population. Using the triploid 'Haida No. 2' Pacific oysters as the female parent and the diploid 'Haida No. 2' Pacific oysters as the male parent, tetraploid 'Haida No. 2' Pacific oysters were induced to form a base population. Through four generations of population selection, tetraploid 'Haida No. 2' Pacific oysters were obtained. c. Using the diploid 'Haida No. 3' (GS-01-007-2018) Pacific oyster as the base population, triploid 'Haida No. 3' Pacific oysters were induced to form a base population. Using the triploid 'Haida No. 3' Pacific oysters as the female parent and the diploid 'Haida No. 3' Pacific oysters as the male parent, tetraploid 'Haida No. 3' Pacific oysters were induced to form a base population. Through four generations of population selection, tetraploid 'Haida No. 3' Pacific oysters were obtained. d. Select diploid Fujian oysters with common shell color, gold and black as parents, and obtain diploid Fujian oyster strains with common shell, gold shell and black shell through two consecutive generations of population selection; e. Using the diploid Fujian oyster common shell color strain as the base population, induce the production of the triploid Fujian oyster common shell color strain. Using the triploid Fujian oyster common shell color strain as the female parent and the diploid Fujian oyster common shell color strain as the male parent, induce the production of the tetraploid Fujian oyster common shell color strain as the base population. Through two consecutive generations of population selection, obtain the tetraploid Fujian oyster common shell color strain. f. Using the diploid Fujian oyster shell gold line as the base population, induce the formation of the triploid Fujian oyster shell gold line. Using the triploid Fujian oyster shell gold line as the female parent and the diploid Fujian oyster shell gold line as the male parent, induce the formation of the tetraploid Fujian oyster shell gold line as the base population. Select and breed the population for two consecutive generations to obtain the tetraploid Fujian oyster shell gold line. g. Using the diploid Fujian oyster shell black strain as the base population, induce the formation of the triploid Fujian oyster shell black strain. Using the triploid Fujian oyster shell black strain as the female parent and the diploid Fujian oyster shell black strain as the male parent, induce the formation of the tetraploid Fujian oyster shell black strain as the base population. After two consecutive generations of population selection, obtain the tetraploid Fujian oyster shell black strain. h. Using the diploid Fujian oyster common, shell gold and shell black strains described in step (d) as the female parent, and the tetraploid Pacific oysters "Haida No. 1", "Haida No. 2" and "Haida No. 4" described in steps (a), (b) and (c) as the male parent, hybridization can yield a new Fuchang hybrid triploid oyster strain; using the Pacific oysters "Haida No. 1", "Haida No. 2" and "Haida No. 4" as the female parent, and the tetraploid Fujian oyster common, shell gold and shell black strains described in steps (e), (f) and (g) as the male parent, hybridization can yield a new Changfu hybrid triploid oyster strain.

2. The method for breeding a new strain of fast-growing high-temperature-resistant hybrid triploid oysters according to claim 1, characterized in that: In steps (a), (b), (c), (e), (f), and (g), the triploid Crassostrea gigas oysters “Haida No. 1,” “Haida No. 2,” and “Haida No. 3” are induced, as are the triploid Crassostrea gigas common, shell gold, and shell black strains. After fertilization for 15 minutes, 0.75 mg / L of cytochalasin B is added and treated for another 15 minutes. Then, the eggs are washed with 2 mg / L dimethyl sulfoxide solution. The groups with a ploidy retention rate of over 95% in the larvae are tested. The larvae are then raised and the adult oysters are grown using conventional methods, thus obtaining the triploid induced groups of the above six strains.

3. The method for breeding a new strain of fast-growing high-temperature-resistant hybrid triploid oysters according to claim 1, characterized in that: In steps (a), (b), (c), (e), (f), and (g), the tetraploid oysters "Haida No. 1", "Haida No. 2", and "Haida No. 3" are induced, and the tetraploid Fujian oysters common, shell gold, and shell black strains are induced. After fertilization for 8-10 minutes, 1 mg / L of cytochalasin B is added and the treatment is continued for 8-10 minutes. The tetraploid induced groups of the above six strains are obtained when the ploidy retention rate of the larvae is above 80%.

4. The method for breeding a new strain of fast-growing high-temperature-resistant hybrid triploid oysters according to claim 1, characterized in that: In steps (a), (b), (c), (e), (f), and (g), when selecting individuals from the six tetraploid strains mentioned above, the top 10% of individuals in terms of shell height and total weight are selected, and more than 100 males and 100 females are selected in each generation. This high-intensity selection process is carried out for 2 to 4 generations.

5. The method for breeding a new strain of fast-growing high-temperature-resistant hybrid triploid oysters according to claim 1, characterized in that: In step (d), when selecting populations for the above-mentioned diploid Fujian oyster common, golden-shelled and black-shelled strains, oysters with good vitality, beautiful shell shape and no damage and pure shell color are selected as parent oysters. The top 10% of individuals in shell height and wet weight are selected and continuously selected for 2 to 3 generations with high intensity.

6. The method for breeding a new strain of fast-growing high-temperature-resistant hybrid triploid oysters according to claim 1, characterized in that: In step (h), individuals with uniform development, ≥15 million eggs, deep yolk color, and pure shell color are selected from different diploid populations as maternal parents, and individuals with pure shell color and vigorous sperm motility are selected from different tetraploid populations as paternal parents. By using conventional methods for larval rearing and adult oyster cultivation, a new fast-growing, heat-resistant hybrid triploid oyster strain can be obtained.

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