CN100444725C - Breeding method of high-yielding and stress-resistant hybrid scallop varieties - Google Patents

Abstract

A breeding method for a high-yield stress-resistant hybrid scallop variety, mainly through continuous multi-generation selective breeding to obtain a high-yield chlamysalis CDS5 female parent line, and then re-crossing with the Chlamys farreri JNR group through distant crosses A high-yield and stress-resistant ZHJ male line was obtained. Using CDS5 female parent line and ZHJ male parent line to cross, solve broiler breeding, realize the simultaneous development and maturity of parental gonads, and master the seedling breeding technology of the first generation of hybrids, and cultivate the first generation of hybrids with high yield and stress resistance. The present invention is applicable to large-scale production of scallops, and the first generation of hybrids cultivated, compared with conventional scallop species for production, has a growth rate of 35% and a survival rate of more than 200% through the cultivation test. The development and application will increase the production of scallop culture by 30-50% under the existing conditions.

Description

Breeding method of high-yielding and stress-resistant hybrid scallop varieties

Technical field:

The invention belongs to the technical field of marine biology, and belongs to the compound breeding scheme combining selective breeding and distant hybrid breeding technology in the study of genetic improvement of shellfish, specifically a method for breeding high-yield and stress-resistant hybrid scallop varieties

Background technique:

Scallop has always been one of the main species in my country's mariculture industry. For many years, the scale and output of scallop cultivation in my country rank first in the world. However, since the mass death of Chlamys farreri broke out in the summer of 1997, the species structure of scallop culture in my country has undergone major changes. The aquaculture output of scallops has been around 100,000 tons. Chlamys farreri is a local scallop species naturally distributed in the coastal waters of my country. Compared with imported bay scallops, it has the advantages of tender meat, delicious taste, and rich nutrition. It conforms to the eating habits and flavor of Chinese people, and is also very popular in the international market. my country's important export aquatic products. The rejuvenation of the Chlamys farreri aquaculture industry needs to be carried out urgently, which is of great significance for improving the nutritional structure of the Chinese people's diet, improving the living standards of the Chinese people and increasing foreign exchange earnings from exports.

In the process of Chlamys farreri aquaculture, there are two outstanding problems that bother the farmers, which seriously dampens the enthusiasm of the masses, and also inhibits the development and recovery of Chlamys farreri aquaculture in my country. The first outstanding problem is the high mortality rate in summer, and mass deaths occur year after year. In spring and summer, the summer mortality rate of naturally collected seedlings in the sea area is more than 70% in the current year, and the mortality rate in the summer of the next year is more than 90%. The second outstanding problem is that the genetic stability of traits is poor, which is not convenient for the unified operation and management of production. Commercial seedlings grow slowly, have poor uniformity, and the proportion of small individuals is an important reason for their mortality rate as high as 70%. Small individual seedlings have very weak tolerance to high temperatures, and it is difficult for scallops below 5mm to survive the summer before the beginning of summer. .

In production, there is a strong demand for cultured Chlamys farreri with fast growth, high consistency of characters and high temperature resistance.

Invention content:

The purpose of the present invention is to provide a breeding method for high-yield and stress-resistant hybrid scallop varieties, to breed hybrid scallop seedlings with fast growth, high character consistency, and strong stress resistance, so as to effectively solve the outstanding problems and contradictions existing in the production of scallops in my country , to promote the development and industrial revival of my country's dominant scallop species breeding.

The present invention is accomplished according to the following operation methods:

Firstly, CDS5 female parent line and ZHJ male parent line are cultivated, then the synchronous development and maturation of the gonads of both parents are regulated, cross fertilization is carried out, and finally a generation of hybrid seedlings is cultivated.

The method for cultivating the female parent line of CDS5 is to select the growth rate of 4-7 cm/year for the Changdao population of Chlamys farreri for multiple generations of selective breeding based on the index of shell height.

The method of cultivating the ZHJ male parent line is to use the female parent of the distant hybrid progeny of Chlamys farreri and Chlamys grandis as the female parent, and then re-cross with the male shells of the breeding population of Chlamys farreri Jiaonan population to obtain high-yield resistance. Inverse ZHJ system.

During the cross fertilization process of CDS5 female parent line and ZHJ male parent line, the number of individuals of ZHJ male parent line is guaranteed to be more than 100.

The method of regulating the simultaneous development and maturation of parental gonads is that the ZHJ male line should be cultivated in the pond one week earlier than the CDS5 female line, and entered the pond successively in the middle and early March. After stabilizing for 2-3 days, raise the temperature by 0.5-1°C every day, and finally cultivate broodstock at a stable temperature of 14-16°C. In the middle stage of culture, you should often observe the progress of gonad development, and take measures such as adjusting temperature, light, and feeding bait to achieve synchronous maturation of parents. In the first 2-3 days, the daily change of the water temperature is within 0.5°C. It is forbidden to pour the pond and change the water. The bait should be fed gently, and the remaining bait and feces at the bottom of the pond should be sucked frequently; After the ejaculation of this system, add sperm to the spawning pool, and the number of sperm should be 3-5 visible around each egg under the microscope;

The breeding method of the first-generation hybrid seedlings is that when the fertilized eggs develop into D-shaped larvae after about 28 hours after hybridization, they are selected and transferred to the larvae culture tank for cultivation. The water temperature for larvae cultivation should be stable at 20-22°C, and golden algae are used as their opening bait. , in the middle and late stages of cultivation, it can be fed with Chrysophytes, diatoms and flat algae and other single-celled algae, and other management during the hybrid scallop larvae is the same as that of Chlamys farreri.

Practice has proved that the CDS5 female parent line bred by multi-generation selective breeding is crossed with the ZHJ male parent line obtained by crossing the distant crosses of Chlamys farreri and Chlamys grandis. The morphology and nutritional components of the hybrid scallop obtained are similar to those of the wild Chlamys farreri in natural sea areas. The outstanding advantages are bright red shell color, fast growth, high consistency of traits, and high temperature resistance. Has the following characteristics:

Compared with the existing technology, the scallop bred by the technology of the present invention combines the accumulation of growth genes and the utilization of heterosis; by virtue of the selective breeding of the long island population of Chlamys farreri for multiple generations, the shell color is bright red, the growth rate is fast, and the fecundity is high. Strong female parent line with high consistency of traits; on the basis of selective breeding, through distant hybridization and compound hybridization techniques of Chlamys farreri and Chlamysgui scallops, a red shell color, strong stress resistance, fast growth, The male parent line with a high degree of genetic consistency; the obtained female parent line and the duplicate line can be crossed to facilitate the production of commercial seedlings of hybrid scallops. After about 70 days of cultivation (from fertilization), the commercial seedlings obtained are the smallest The specification can reach 5mm, with an average of more than 7mm.

Management is convenient in the cultivation process of the present invention, and when annual summer survival rate (to spring seedling) is more than 70% (conventional seedling≤30%), next year summer survival rate can reach 30-40% (conventional seedling≤30%) 10%); the 14-month-old scallop shell can reach more than 6.5cm in height, and can reach more than 7cm in some sea areas (conventional seedlings vary in the range of 3-6cm, with an average of ≤5cm).

Detailed ways

The specific operation process of the best embodiment: the key operation process includes parent-child culture, hybrid fertilization, and larvae culture.

The female parent CDS5 line and the male parent ZHJ line can be purchased from the national "863" project scallop original seed breeding base (Yantai and Qingdao).

1 brood culture

Parents should be cultured in the pool 15 to 25 days before the planned spawning. Because the gonad development of the ZHJ male line is relatively slow, it is advisable to enter the pool one week before the CDS5 female line.

1) Culture conditions:

(1) Cultivation pool: cement pool or FRP water tank, 10-30m ³ , water depth 1.1-1.5m; (2) Water quality: water source complies with the regulations of GB 11607, cultivation water complies with the regulations of NY 5052; (3) Water temperature: from its The water temperature of the habitat is gradually increased to 14-16°C for cultivation; (4) salinity: 25-32; (5) light: 500-10001x; (6) cultivation density: 100-120/m ³ , using multi-layer nets Cages or single-layer floating cages are used as cultivation containers.

2) Daily management

(1) Treatment of broccoli entering the pond: before entering the pond, the attached organisms and floating mud on the shells should be removed. Before entering the pool, the sex should be preliminarily selected, and the male shellfish in the SDS5 female parent line and the female shellfish in the ZHJ male parent line that can be clearly identified should be eliminated. In the middle stage of the cultivation process, the male shellfish in the SDS5 female parent line and the female shellfish in the ZHJ male parent line should be selected again and eliminated. (2) Feeding: Feed diatoms, chrysophytes or flat algae and other unicellular algae or starch, spirulina powder, egg yolk and other substitute baits. When the water temperature is lower than 10°C, the daily feeding amount is (12-15)×10 ⁴ cells/ml; when the water temperature is above 10°C, gradually increase the feeding amount, and when it reaches 14°C, the daily feeding amount is (35-40)×10 ⁴ cells/ml . Feed 6-12 times a day. In the middle and late stages of broiler breeding, the feeding amount should be adjusted appropriately according to the development progress of the parents to achieve the simultaneous maturation of the parents. (3) Water change: 2-3 times a day in the early and mid-term, 100% of the daily water change; 1-2 times a day in the late stage, 1/3 of the daily water change, if conditions permit, try to drain water from the bottom of the pool, and keep the water temperature constant . (4) Pond pouring: In the early and middle stages, the pond is poured every other day to clear the bottom; the pond is not poured before the eggs are collected. (5) Bottom absorption: In the early and middle stages, the bottom is sucked once a day in the morning and in the evening; in the late stage, the number of bottom suctions should be appropriately increased. (6) Heating: After the broodstock enters the pond, keep it stable for 2-3 days in the water temperature close to the broodstock habitat, and then raise it by 0.5-1.0°C to 14-16°C every day, and cultivate at this temperature. (7) Inflation: continuous micro-inflation. (8) Effective accumulated temperature: the range of effective accumulated temperature in the stable culture stage is 150-200°C per day.

2 cross fertilization

In order to maintain the level of genetic diversity of scallops, the number of ZHJ male lines involved in breeding and fertilization in the process of large-scale hybrid production should be guaranteed to be more than 100. ; The ZHJ male parent line should be cultivated in the pond one week earlier than the CDS5 female parent line. Generally, it is advisable to enter the pond successively in the middle of March and last month (it can ensure that the scallops can get eggs in April); The water temperature in the broodstock environment is similar. After stabilizing for 2-3 days, the temperature rises by 0.5-1°C every day, and finally stabilizes at 14-16°C to cultivate broodstock. In the middle stage of cultivation, the progress of gonad development should be observed frequently, and measures such as adjusting temperature, light and feeding bait should be taken to achieve Both parents mature at the same time. When the daily change of water temperature is within 0.5°C for 2-3 days before delivery, it is forbidden to pour the pond and change the water. After more ZHJ male parent lines ejaculate sperm, add sperm to the spawning pool. The number of sperm should be 3-5 visible around each egg by microscopic examination. On the day of spawning, the sex of the brood shells can be accurately selected again when drying in the shade, and the males or suspicious females in the SDS5 female line and the females or suspicious males in the ZHJ male line are discarded.

3. Larval Culture

The hybrid embryos develop into D-shaped larvae after about 28 hours. They should be selected and transferred to the larvae culture tank for cultivation. The water temperature for larvae cultivation should be stable at 20-22°C. Golden algae should be used as their opening bait. It can be fed in the middle and late stages of cultivation Single-cell algae such as golden algae, diatoms, and flat algae. Other management methods are the same as that of Chlamys farreri.

Breeding of CDS5 female parent line and ZHJ male parent line and test results of hybrid scallop production

Breeding process of CDS5 female parent line: Selective breeding of scallop high-yield and stress-resistant traits was carried out on the wild population of Chlamys farreri from Changdao to form a scallop population with high-yield, stress resistance, red shell color and basically stable genetic performance.

The breeding process of ZHJ male parent line: Selected and bred individuals with specific production traits of rapid growth, strong stress resistance, and red shell color from the distant hybrid progenies of part of the scallop breeding line and the scallop scallop. Then it was combined with Jiaonan selection group, and the complex hybrid male parent group (ZHJ complex male parent line) was established through the selection of offspring.

The CDS5 female parent line is then crossed with the ZHJ male parent line, and the hybrid progeny has the characteristics of rapid growth, outstanding stress resistance, bright red shell color, and a genetic stability of more than 95%. The cross fertilization rate of CDS5 female parent line and ZHJ line is over 90%, and the hatching rate is over 85%. The offspring of the hybrid are excellent in character and bright red in shell color, and are called Haida Penglai Red Scallop by farmers. The test results in 2003-2004 are shown in Table 1 and Table 2.

Table 1 Comparison of control test results of hybrid scallop production and seedling attachment for 60 days (2003)

The control is seedlings obtained from natural seedling collection in the Taozi Bay sea area of Yantai. The shell color is the result of 1000 individuals, and the shell height is the statistical result of random observation of 100 individuals. Table 2 Comparison of observation results of hybrid scallop production control growth test (2003-2004)

The control was cultivated from natural seedlings collected in the sea area of Taozi Bay, Yantai. The shell color is the result of 1000 individuals, and the shell height and live weight are the average value of 100 individuals observed randomly, which are the results of 14-month-old records. Random observation of mortality in ten scallop growing cages

Claims (6)

1. A breeding method for a high-yield stress-resistant hybrid scallop variety, which is characterized in that firstly cultivating CDS5 female parent line and ZHJ male parent line, then regulating the synchronous development and maturation of the gonads of both parents, carrying out cross fertilization, and finally cultivating a generation of hybrid seedlings. 2. The method for breeding high-yield and stress-resistant hybrid scallop varieties according to claim 1, characterized in that the method of cultivating the CDS5 female parent line is the long island population of Chlamys farreri, and the growth rate is selected to be 4-7cm/year based on the shell height index , obtained by continuous multi-generation selection breeding. 3. The method for breeding high-yielding and stress-resistant hybrid scallop varieties according to claim 1, characterized in that the method for cultivating the ZHJ male parent line is to use the female shellfish in the distant hybrid progeny of the CDS5 line of Chlamys farreri and Chlamys chinensis as The female parent was re-crossed with the male clamshell in the breeding group of Chlamys farreri Jiaonan population to obtain the high-yielding and stress-resistant ZHJ line. 4. The method for breeding high-yield and stress-resistant hybrid scallop varieties according to claim 1, characterized in that in the process of hybridization and fertilization of CDS5 female parent line and ZHJ male parent line, the number of individuals of ZHJ male parent line is guaranteed to be more than 100. 5. The method for breeding high-yield and stress-resistant hybrid scallop varieties according to claim 1, characterized in that the method of regulating the synchronous development and maturation of the gonads of both parents is that the ZHJ male parent line should be cultivated in the pond one week earlier than the CDS5 female parent line. Enter the pool successively in the middle and early ten days, and the gonads are cultivated by raising the temperature. The water temperature in the pool is consistent with the water temperature of the broodstock habitat. After 2-3 days of stability, the temperature is raised by 0.5-1°C every day, and finally stabilized at 14-16°C to cultivate the broodstock. Observe the development progress of the gonads, and take conventional measures of adjusting temperature, light and feeding bait to realize the simultaneous maturation of both parents. The daily change of water temperature is within 0.5°C 2-3 days before delivery. It is forbidden to pour the pond and change the water, and the bait should be fed gently. Frequently suck the remaining bait and feces at the bottom of the pond; the temperature of the induced spawning water is 20-22°C. After more ZHJ male lines have ejaculated, add sperm to the spawning pond. The number of sperm can be seen around each egg by microscopic examination. 3-5 sperm. 6. The method for breeding high-yield and stress-resistant hybrid scallop varieties according to claim 1, characterized in that the breeding method of the first-generation hybrid seedlings is that when the fertilized eggs develop into D-shaped larvae after about 28 hours after hybridization, they are selected and transferred to larval culture Cultivate in the pond, the water temperature for larvae cultivation should be stable at 20-22°C, use golden algae as their opening bait, and feed them with golden algae, diatoms or flat algae in the middle and late stages of cultivation, and other species during the hybridization period of scallop larvae Managed with Chlamys farreri.