CN101518215A

CN101518215A - Method for cultivating cold-resistance gift tilapia

Info

Publication number: CN101518215A
Application number: CN200910024531A
Authority: CN
Inventors: 何杰; 徐跑; 朱健; 董在杰; 朱志强
Original assignee: Freshwater Fisheries Research Center of Chinese Academy of Fishery Sciences
Current assignee: Freshwater Fisheries Research Center of Chinese Academy of Fishery Sciences
Priority date: 2009-02-10
Filing date: 2009-02-10
Publication date: 2009-09-02
Anticipated expiration: 2029-02-10
Also published as: CN101518215B

Abstract

The invention discloses a method for cultivating cold-resistance gift tilapia. The method adopts the establishment of a plurality of pedigrees and selects a pedigree of which an average cold-resistance variance is higher than a total variance as a primitive pedigree through a cold-resistance test. In the May of the following year, a female and a male of the primitive pedigree mate for propagation. After emergency from eggs, fish fry passes through growth selection and cold-resistance selection as well as a growth comparison test to select a pedigree growing faster than a reference gift tilapia and having a cold-resistance variance higher than a cold-resistance total variance of the time as the first pedigree. The selection and the test are both carried in a mesh box. The first pedigree is protected as parent stock in winter and passes the selection of a second pedigree in the same way in the following year. Researches show that the total variance of the cold-resistance selection is obviously higher year by year. Through selection generation by generation, gift tilapia which grows fast and is fully improved in cold resistance can be obtained.

Description

The breeding method of cold-resistance gift tilapia

Technical field

The invention belongs to the fish breeding technical field, specifically is the cold-resistant strain development technology of Tilapia mossambica.

Background technology

The tool growth vigor of lucky rich strain Tilapia mossambica, but cold-resistant proterties than present main breed variety Buddhist nun difficult to understand hybridize Tilapia mossambica a little less than, the improvement of its cold performance can become the alternative kind that Tilapia mossambica is cultured.The cold-resistant proterties of fish is the emphasis of fish breeding research, also is the bottleneck of restriction fish industry development.At present, few to the cold-resistant aspect of fish report, only limit to fish to the temperature adaptation mechanism, low temperature is to the influence of Tilapia mossambica, and the cold performance of existing strain Tilapia mossambica relatively, with by domestication by low temperature or the continuous low temperature selection improvement Tilapia mossambica possibility of low temperature resistant proterties not, also do not work out method and measure that the cold-resistant proterties of Tilapia mossambica is improved.Aspect molecular biology, at present cold-resistant gene has been done some explorations, go but be difficult to be applied in a short time in the production reality.

Summary of the invention

The purpose of this invention is to provide a kind of breeding method, unite selection for many generations by a plurality of familys, can not only effectively solve the reorganization issues of purification of the cold-resistant gene of lucky rich strain Tilapia mossambica, guarantee that also selected cold-resistant strain has the merit of fast growth simultaneously.

The technical solution adopted for the present invention to solve the technical problems:

1, the foundation of original family: use existing common gift tilapia family, or set up several gift tilapia familys, set up several original familys through cold-resistant selection again with the method that genetics is set up family.

The method of cold-resistant selection: get a part of fish in the family of carrying out cold-resistant selection, put into respectively in the identical net cage that pre-sets, each family is placed on two (or three) net cages respectively, one cubic metre of size of net cage, each net cage is put the fish (general 20 to 30 tails) of equal number, all net cages are arranged in the same pond of the same terms, carry out unified management.Dark 100 centimetres of net cage, in the case depth of water 50-70 centimetre, put in each net cage the identical inflation of aeration quantity first, keep that dissolved oxygen keeps water quality good and as clear as crystal so that observe in the case more than 5 mg/litre.A plurality of familys through natural temperature-fall period in cold period, write down the mean value of each family percentage survival under the otherwise limit temperature condition under the same conditions.Calculate the variance of total variance and each family, compare, keep the family that is higher than total variance and do further seed selection.

2, to two reselection procedure of original family: the selection of female, individual size of male parent of original family and fry growth period speed during by breeding, and the screening of cold-resistant test, original family is grown and cold-resistant double selection, select the good family of growth rate and cold performance.

The first step: growth is selected.5-6 month, when water temperature rises to 25 ℃, from original family select individual big, gonad development is female preferably, the individual breeding of carrying out between family of pairing one to one of male parent, every pair of fish is put into a net cage, carries out numbering and record, checks after three days that raun is (under the natural situation, raun can be in the fertilized egg suction side, in the oral cavity, hatch), from female lymphogranuloma inguinale, in hatching pail, carry out artificial incubation behind the taking-up ovum grain, the rauns that general body weight reaches 150 grams lay eggs can be more than 1000.The fry that hatches is cultured in net cage, and regularly carries out growth rate and select, and selects individual bigger and healthy and strong fry, and selection intensity about 30% (promptly eliminating 70%) is generally selected three times (selecting for the first time to keep 1000-1200 tail fry).In breeding process, carry out the growth comparative trial between family.

Second step: cold-resistant selection.Culture to low temperature season and carry out cold-resistant selection between family again, the result keeps growth and all higher family of cold-resistant value, i.e. first generation family, first generation family are protected and kind survived the winter, and carry out the foundation of the second generation family coming year.In cold-resistant test, hybridize Tilapia mossambica in contrast with Buddhist nun difficult to understand, find to have the approaching or better family existence of cold-resistant effect and control group, be the target strain of selection.

Beneficial effect: this invention is based upon growth rate to the selection of cold-resistant strain carries out between family faster, has guaranteed that selected cold-resistant strain of coming out must possess growth and the combination of cold-resistant proterties height.Avoided present fish to select to select several characteristic indexs simultaneously in the breeding process like this, often attended to one thing and lose sight of another, on the index, another index has really been gone down, length consuming time, select difficulty, the process complexity also is difficult to reach problems such as growth and cold-resistant merit high unity.The present invention also takes into full account the effect that two aspects are renderd a service in the heredity of gene genetic and environment, and operation is simple and feasible and practical, and method is comparatively comprehensive, can comparatively fast reach the target of selection.The improvement of lucky rich strain Tilapia mossambica cold tolerance can improve overwintering survival rate greatly, saves cost, improves output, enlarges it and cultures promoted extension.

Embodiment

Embodiment:

1, sets up the original family of cold-resistant breeding

In November, first, we have selected 30 from existing gift tilapia family, carried out cold-resistant selection.Each family is got fish 40 tails, and every urosome weighs about 160 grams, divides two groups, and every group 20 tail divides in two net cages that are placed in the greenhouse, and all net cages are arranged in the identical pond of condition.1 cubic metre of net cage size, the depth of water is 60 centimetres in the case, and each net cage is put into and is inflated first, and dissolved oxygen reaches 8 mg/litre in the net cage, keeps water quality as clear as crystal so that observe, and carries out the management under the same terms.When water temperature is reduced near 12 ℃ of the limiting values, observe and write down the survival rate under the different temperatures situation, survival rate to last family is zero, calculate the average variance and the population mean variance of each family, the family that is higher than population mean is kept, the result has kept 13 familys, promptly original family.Then, carry out further over wintering.

2, with growth selection and cold-resistant selection original family is carried out two reselection procedure:

The first step: growth is selected.In May, second is when rising to 25 ℃ of left and right sides when water temperature, selects individual big, female preferably, the male individuality of gonad development from 13 original familys and carries out male and female between original family and match breeding one to one.Consider situations such as the individual gonad development of the scale of breeding and male and female, the result has joined 32 pairs, is less than theoretical value 2C ₁₃ ²=156 pairs.The net cage that the every pair of fish is put into same 1 cubic metre of size is bred, and carries out numbering and record, and the depth of water is 70 centimetres in the net cage, and all net cages are located in the same pond.(this moment, water temperature was 25.5 ℃) take out fertilized egg after 3 days from female lymphogranuloma inguinale, and the every tail 180-210 gram of raun size is got the ovum amount at 1300-3000 grain/tail, and the fertilized egg of taking-up is carried out artificial incubation in hatching pail.Fry hatches the back to be cultured in net cage, and body reached about 3 centimetres in 10 days, and each family is selected zero defect, individual bigger and healthy and strong fry 1000 tails, has selected twice again every 15 days, to 300 tails, and 100 tails, selection intensity is 30%.Each family is still cultured respectively in net cage.

In culturing, the comparative trial of growing: hybridize Tilapia mossambica in contrast with Buddhist nun difficult to understand, test is carried out in net cage, each family is got each 40 tail of fry about 25 grams, put into two net cages respectively by equal number, 1 cubic metre of size of net cage, 70 centimetres of the depth of waters of submerging, under identical raising condition, cultured 20 days, found that have 28 familys of growth rate faster than control group.

Second step: cold-resistant selection.Then December, from 28 gift tilapia familys that growth is selected to remain, each family is got 40 fishes and is divided into two groups, every group 20 tail, put into respectively in the identical net cage that pre-sets, one cubic metre of size of net cage, and hybridize Tilapia mossambica in contrast with Buddhist nun difficult to understand.All net cages are arranged in the same pond of the same terms, carry out unified management, and the depth of water is 60 centimetres in the case, put in each net cage the identical inflation of aeration quantity first, dissolved oxygen reaches 8 mg/litre in the net cage, keeps water quality as clear as crystal so that observe.Cooling through under the nature when water temperature drops to 12 ℃, has fish to begin death, writes down the mean value of each test family percentage survival under different extreme temperature conditions.Calculate the variance of total variance and each family, found that the family that is higher than total variance has 14 (being first generation family).The cold-resistant total variance of first generation family increases significant difference than original family.The total variance of first generation family than original family near control group.After 14 first generation family guarantors plant and survive the winter,, carry out the foundation of the second generation family coming year again as further seed selection.

Claims

1, a kind of breeding method of cold-resistance gift tilapia is characterized in that may further comprise the steps:

A. the foundation of original family: use existing common gift tilapia family, or set up several gift tilapia familys, set up several original familys through cold-resistant selection again with the method that genetics is set up family;

B. to two reselection procedure of original family: the selection of female, individual size of male parent of original family and fry growth period speed during by breeding, and the screening of cold-resistant test, original family is grown and cold-resistant dual selecting, select the good family of growth rate and cold performance.

2, the breeding method of cold-resistance gift tilapia as claimed in claim 1, it is characterized in that described cold-resistant selection be a plurality of familys under the same conditions, through natural temperature-fall period in cold period, write down the mean value of each family percentage survival under the otherwise limit temperature condition, calculate total variance and each family variance, keep the family that is higher than total variance and do further seed selection.

3, the breeding method of cold-resistance gift tilapia as claimed in claim 1, it is characterized in that it is that individual bigger and healthy and strong fry is selected in female between family, the male individual breeding of pairing one to one back that described growth is selected, selection intensity is 30%, select three times, each family keeps about 100 tails at last.