Method for breeding hybrid seed of Portuguese oyster tetraploid and Hong Kong oyster

Abstract

The present invention relates to the technical field of oyster breeding, and in particular to a method for breeding hybrid seedlings of Portuguese oyster tetraploid and Hong Kong oyster. The method comprises the following steps: crossbreeding the Portuguese oyster tetraploid with the Hong Kong oyster, culturing the hybrid fertilized eggs obtained by the breeding in a first gradient liquid, then transferring the hybrid fertilized eggs cultivated in the first gradient liquid to a second gradient liquid for cultivation, and cultivating the hybrid larvae in seawater after eye spots appear. The method uses the Portuguese oyster tetraploid as the male parent and the Hong Kong oyster as the female parent to hybridize to obtain hybrid fertilized eggs, induces the hybrid fertilized eggs twice with a calcium gluconate salt solution and a calcium chloride salt solution, and then breeds them according to a conventional breeding method. The hybrid oysters thus bred have a good growth rate in the larval stage, thereby accelerating the breeding speed of the hybrid oysters and being suitable for large-scale breeding.

Description

Technical Field

[0001] The invention relates to the technical field of oyster breeding, and in particular to a method for breeding hybrid seedlings of Portuguese oyster tetraploid and Hong Kong oyster. Background Art

[0002] The Portuguese oyster, also known as the Fujian oyster, belongs to the phylum Mollusca, class Bivalvia, order Plectranthus, family Ostreae, and genus Crassostreatus. It is an important aquaculture shellfish in South China. Not only is the Portuguese oyster delicious and nutritious, but it also possesses unique health benefits and medicinal properties, making it a highly nutritious seafood delicacy. The Hong Kong oyster is a native species of southern my country, primarily found in Guangdong and Guangxi.

[0003] A patent with patent number CN201410509937.1, "A method for breeding juvenile oysters using oviparous means," already exists. However, the oysters bred by the provided method grow slowly, which in turn affects the speed of oyster breeding. At the same time, it also restricts the scale of oyster breeding and cannot meet the users' needs for oyster breeding.

[0004] In summary, the research and development of breeding methods for tetraploid Portuguese oysters and hybrid seedlings of Hong Kong oysters remains a key issue that needs to be urgently addressed in the field of oyster breeding technology. Summary of the Invention

[0005] In view of the above-mentioned shortcomings of the prior art, the present invention provides a method for breeding hybrid seedlings of Portuguese oyster tetraploid and Hong Kong oyster. The present invention uses Portuguese oyster tetraploid as the male parent and Hong Kong oyster as the female parent to obtain hybrid fertilized eggs through hybridization. The hybrid fertilized eggs are induced for the first time with a calcium gluconate salt solution, and then the hybrid fertilized eggs after the first induction are transferred to a calcium chloride salt solution for a second induction. After the two inductions, the hybrid oysters are bred according to a conventional breeding method. The bred hybrid oysters have a good growth rate in the larval stage, thereby accelerating the breeding speed of the hybrid oysters. The method is suitable for large-scale breeding, has broad application prospects, and is worthy of promotion.

[0006] To achieve the above object, the present invention provides the following technical solutions:

[0007] A method for breeding hybrid seed of tetraploid Portuguese oysters and Hong Kong oysters, the method comprising the steps of hybridizing the tetraploid Portuguese oysters and the Hong Kong oysters, cultivating the hybrid fertilized eggs obtained by the breeding in a first gradient liquid, and then transferring the hybrid fertilized eggs cultivated in the first gradient liquid to a second gradient liquid for cultivation, and cultivating the hybrid larvae in seawater after eye spots appear.

[0008] Furthermore, the hybrid breeding is carried out by artificially hybridizing the tetraploid male parent of Portuguese oysters with the female parent of Hong Kong oysters.

[0009] Furthermore, the Portuguese oyster tetraploid is a purebred individual that is more than two years old and has a size of 8-10 cm.

[0010] In addition, the Hong Kong oysters are one-year-old purebred individuals with a size of 6-8 cm.

[0011] Wherein, the first gradient solution is a calcium gluconate solution with a salinity of 12-14 and a temperature of 23-25°C.

[0012] Furthermore, the hybrid fertilized eggs are incubated in the first gradient solution for 8-12 minutes.

[0013] Wherein, the second gradient liquid is a calcium chloride salt solution with a salinity of 10-12.

[0014] Furthermore, the hybrid fertilized eggs are incubated in the second gradient solution for 12-15 minutes at a temperature of 23-25°C.

[0015] Furthermore, the artificial hybridization is to mix the sperm of the Portuguese oyster tetraploid with the eggs of the Hong Kong oyster in a ratio of 20:1 for fertilization, and then manually select the successfully fertilized eggs.

[0016] Furthermore, the cultivation and shaping is to cultivate the hybrid larvae with eyespots into adult oysters according to the common cultivation method.

[0017] Beneficial effects

[0018] Compared with the known public technology, the technical solution provided by the present invention has the following beneficial effects:

[0019] The invention uses a Portuguese oyster tetraploid as the male parent and a Hong Kong oyster as the female parent to obtain hybrid fertilized eggs through hybridization, performs a first induction on the hybrid fertilized eggs through a calcium gluconate salt solution, and then transfers the hybrid fertilized eggs after the first induction into a calcium chloride salt solution for a second induction. After the two inductions, the hybrid oysters are bred according to a conventional breeding method. The bred hybrid oysters have a good growth rate in the larval stage, thereby accelerating the breeding speed of the hybrid oysters, and are suitable for large-scale breeding. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 This is a statistical histogram of the shell length of hybrid oysters on the second day in Example 4 of the present invention;

[0021] Figure 2 This is a statistical histogram of the shell length of hybrid oysters on the 8th day in Example 4 of the present invention;

[0022] Figure 3This is a statistical histogram of the shell length of the hybrid oysters in Example 4 of the present invention on the 12th day. DETAILED DESCRIPTION

[0023] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts are within the scope of protection of the present invention.

[0024] The present invention will be further described below with reference to the embodiments.

[0025] Example 1: Breeding of the Portuguese tetraploid and Hong Kong oyster hybrid oysters of the present invention

[0026] (1) Purebred Portuguese oyster tetraploids over two years old were selected, and individuals with a size of 8-10 cm were selected from them. At the same time, purebred Hong Kong oysters over one year old were selected, and individuals with a size of 6-8 cm were selected from them. The selected Portuguese oyster tetraploids and Portuguese oysters were synchronously matured and cultured indoors;

[0027] (2) Take the sperm of the tetraploid male of Portuguese oyster and the eggs of the female of Portuguese oyster, select the sperm and eggs with vitality under a microscope, and then soak the eggs in seawater for 30 minutes to ripen;

[0028] (3) artificially hybridizing the sperm and egg in step (2) in a ratio of 20:1 for fertilization, and selecting the successfully fertilized hybrid zygotes under a microscope;

[0029] (4) When 40-50% of the first polar bodies of the hybrid fertilized eggs appear, the hybrid fertilized eggs are subjected to the first induction, that is, the fertilized eggs are cultured in a gluconate calcium salt solution for 8-12 minutes, wherein the salinity of the gluconate calcium salt solution to be tested is 12-14 and the temperature is 23-25°C;

[0030] (5) The hybrid fertilized eggs that have undergone the first induction in step (4) are subjected to a second induction, that is, the hybrid fertilized eggs that have undergone the first induction are moved to a calcium chloride salt solution and incubated for 12-15 minutes, wherein the salinity of the calcium chloride salt solution is 10-12 and the temperature is 23-25°C;

[0031] (6) The hybrid fertilized eggs induced for the second time in step (5) are hatched in normal seawater, and D-shaped larvae are collected after hatching. After the larvae have eyespots, they are cultivated into hybrid oyster body groups with shell fry according to conventional oyster artificial seedling operations, and are cultured on suspended ropes at sea until they reach adulthood.

[0032] Example 2: Effect of two inductions on hybrid oyster breeding

[0033] Hybrid oysters were bred using the method of Example 1 as the experimental group. Meanwhile, steps (4) and (5) in Example 1 were removed, i.e., no secondary induction was performed, and hybrid oysters were bred according to the method of Example 1 as the control group 1. Step (4) in Example 1 was removed, i.e., no first induction was performed, and hybrid oysters were bred according to the method of Example 1 as the control group 2. Step (5) in Example 1 was removed, i.e., no second induction was performed, and hybrid oysters were bred according to the method of Example 1 as the control group 3. The data of the shell length of the hybrid oysters in the larval stage in each group are recorded in Table 1.

[0034] Table 1 Shell length records of each group of hybrid oyster larvae

[0035]

[0036] It can be seen from the relevant data in Table 1 that when no two inductions are performed, the first induction is performed, and the second induction is performed, the shell length of the bred hybrid oysters does not increase significantly during the larval stage. However, after two inductions, the shell length of the bred hybrid oysters increases significantly during the larval stage. Therefore, the present invention can accelerate the breeding speed of hybrid oysters by inducing twice.

[0037] Example 3: Effects of different saline solutions on hybrid oyster breeding

[0038] Hybrid oysters were bred using the method in Example 1 as the experimental group; the calcium gluconate salt solution in the first induction was replaced by potassium chloride and sodium chloride, respectively, while other conditions remained unchanged, and hybrid oysters were bred according to the method in Example 1 as comparative group 1 and comparative example 2; the calcium chloride salt solution in the second induction was replaced by calcium dihydrogen phosphate and seawater, respectively, while other conditions remained unchanged, and hybrid oysters were bred according to the method in Example 1 as comparative group 3 and comparative example 4, and the data of the shell length of the hybrid oysters in each group during the larval stage are recorded in Table 2.

[0039] Table 2 Shell length records of each group of hybrid oyster larvae

[0040]

[0041] It can be seen from the relevant data in Table 2 that the calcium gluconate salt solution used for the first induction and the calcium chloride salt solution used for the second induction of the present invention, compared with potassium chloride or sodium chloride used for the first induction and calcium dihydrogen phosphate or seawater used for the second induction, the calcium gluconate salt solution used for the first induction and the calcium chloride salt solution used for the second induction of the present invention can effectively accelerate the speed of hybrid oyster breeding.

[0042] Example 4: Comparison of the breeding method of the present invention with the prior art method

[0043] The method in Example 1 was used to breed hybrid oysters as the experimental group; and the method of patent application number CN201410509937.1 was used to breed hybrid oysters as the control group. The data of the larval shell length of the hybrid oysters in each group on the 2nd, 8th and 12th days were recorded in Table 3, and the data bar graph was statistically analyzed. Figure 1-3 .

[0044] Table 3 Shell length records of each group of hybrid oyster larvae

[0045]

[0046] Depend on Figure 1-3 As can be seen from the relevant data in Table 3, compared with the traditional breeding method, the method of the present invention can effectively speed up the breeding of hybrid oysters, thereby reducing the breeding cost and is suitable for large-scale breeding.

[0047] The invention uses a Portuguese oyster tetraploid as the male parent and a Hong Kong oyster as the female parent to obtain hybrid fertilized eggs through hybridization, performs a first induction on the hybrid fertilized eggs through a calcium gluconate salt solution, and then transfers the hybrid fertilized eggs after the first induction into a calcium chloride salt solution for a second induction. After the two inductions, the hybrid oysters are bred according to a conventional breeding method. The bred hybrid oysters have a good growth rate in the larval stage, thereby accelerating the breeding speed of the hybrid oysters, and are suitable for large-scale breeding.

[0048] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements will not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims

1. A method for breeding hybrid seedlings of Portuguese oyster tetraploid and Hong Kong oyster, characterized in that: The method comprises hybridizing Portuguese oyster tetraploids with Hong Kong oysters, culturing the hybrid fertilized eggs obtained from the breeding in a first gradient medium, then transferring the hybrid fertilized eggs cultivated in the first gradient medium to a second gradient medium for cultivation, and culturing the hybrid larvae in seawater after the eyespots appear. The hybrid breeding is carried out by artificially hybridizing the tetraploid male parent of Portuguese oysters with the female parent of Hong Kong oysters; The artificial hybridization is to mix the sperm of Portuguese oyster tetraploid and the eggs of Hong Kong oyster in a ratio of 20:1 for fertilization, and manually select the fertilized eggs that are successfully fertilized; The first gradient solution is a calcium gluconate solution with a salinity of 12-14 and a temperature of 23-25°C; The incubation time of hybrid fertilized eggs in the first gradient solution is 8-12 minutes; The second gradient solution is a calcium chloride salt solution with a salinity of 10-12; The hybrid fertilized eggs are incubated in the second gradient solution for 12-15 minutes at a temperature of 23-25°C.

2. The method for breeding hybrid seedlings of Portuguese oyster tetraploid and Hong Kong oyster according to claim 1, characterized in that: The Portuguese oyster tetraploid is a purebred individual over two years old and has a size of 8-10 cm.

3. The method for breeding hybrid seedlings of Portuguese oyster tetraploid and Hong Kong oyster according to claim 1, characterized in that: The Hong Kong oysters are one-year-old purebred individuals with a size of 6-8 cm.

4. The method for breeding hybrid seedlings of Portuguese oyster tetraploid and Hong Kong oyster according to claim 1, characterized in that: The cultivation and shaping is to cultivate the hybrid larvae with eye spots into adult oysters according to a common cultivation method.

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