A method for inducing tetraploids of a new variety of long oyster "Haida No. 2"

Abstract

The invention relates to an induction method for a 'Haida 2#' new variety tetraploid of crassostrea gigas. The induction method comprises the steps of selecting a 'Haida 2#' new variety of crassostreagigas as parent oysters, carrying out manual maturity-promoting culture until the parent oysters are mature, selecting female and male individuals with good gonad development as parent oysters, dissecting for fetching ova, filtering, putting the ova into filtered seawater for maturation, enabling the maturated ova to be fertilized with sperms in the filtered seawater, processing fertilized ova byvirtue of cytochalasin B so as to inhibit the discharging of first polar bodies, after the processing, collecting the fertilized ova, transferring the fertilized ova into an ethanol solution for soaking, finally transferring the fertilized ova into a culture container, and carrying out incubation and larva culture. According to the induction method, the discharging of the first polar bodies of the fertilized ova of the ''Haida 2#'' new variety of a diploid is inhibited by virtue of the cytochalasin B, and the living 'Haida 2#' new variety tetraploids of crassostrea gigas are directly induced,so that the survival rate is greatly increased, and a seedling culturing foundation is provided for the amplified breeding of the 'Haida 2#' new variety tetraploid of crassostrea gigas.

Description

technical field [0001] The invention belongs to the technical field of shellfish breeding, and relates to a polyploid induction method of long oyster, in particular to a tetraploid of a new variety of long oyster "Haida No. method of induction. Background technique [0002] Oyster is the economical shellfish with the widest breeding range and the highest yield in the world. Its meat is delicious and nutritious, and it is known as "milk in the sea". Oyster is one of the four major cultured shellfish in my country. In 2016, the output of oyster culture in my country reached 4.835 million tons, ranking first in the world. However, there are many problems in the long-term oyster farming process, which are mainly reflected in the reduction of genetic diversity and germplasm degradation of oyster farming populations caused by the lack of good breeds and inbreeding, and the frequent occurrence of large-scale mortality, individual miniaturization and shell shape. The decline of eco...

AI Technical Summary

Problems solved by technology

At present, there are two main ways to obtain the triploid oyster "Haida No. 2", one is to directly induce the triploid, but there are three problems in this method: the triploid induction rate is difficult to reach 100%; Toxic effects of induced stress lead to lower survival of larvae; inability to self-sustain population due to sterility of triploid individuals

[0005] At present, there are two main methods for inducing tetraploid oysters. The most commonly used method is to fertilize the sperm of diploid male Oyster oyster and the egg of triploid female, and induce the production of Tetraploids have won international patents. Studies have shown that when the tetraploids obtained by this method are used for the production of triploids, on the one hand, the gonads of the triploids will develop to a certain extent; After 1-2 generations of self-reproduction, the offspring have chromosome loss, and 100% tetraploid cannot be guaranteed, and the triploid rate of hybridization with diploid is not 100%, and it needs to be replaced regularly and re-induced to produce induce

Another method is to use the sperm and eggs of diploid oysters to directly induce oyster tetraploids. Many studies have found that the directly induced tetraploids have the problems of extremely low survival rate and cumbersome operation, but oyster diploids directly The induction of oyster tetraploid also has its irreplaceable advantages. Since the induction process does not use triploid broodstock, the triploid offspring produced by direct induction of tetraploid and diploid hybrids are more sterile, theoretically have higher triploid predominance

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