Double-screening and double-inducing technology system for building disease-resistant grass carp pure line

Abstract

The invention discloses a double-screening and double-inducing technology system for building a disease-resistant grass carp pure line, comprising the following steps of (1) performing artificial infection in a first stage and a second stage to screen out heterozygous grass carps with excellent disease-resistant gene combination; (2) selecting carp sperms which are dead after being hybridized with grass carp ova, activating the growth of disease-resistant heterozygous grass carp ova after a genetic complete inactivation process, and doubling the chromosomes by a cold shock process so as to obtain the grass carps with high homozygous gene combination; (3) performing artificial infection for the obtained female parthenogenesis homozygote grass carps in the first stage and the second stage so as to screen out homozygous grass carps inherited with the excellent disease-resistant gene combination; (4) after the obtained disease-resistant homozygous grass carps are mature in groups, selecting the grass carps which are good in bodily form and fast in growth speed to perform artificial inducing to obtain ova, activating the growth of the genetically inactivated carp sperms and performing chromosome artificial doubling process, and preparing the disease-resistant grass carp pure line with excellent growth performance. Practice proves that the average survival rate of the pure line disease-resistant grass carps reaches above 70 percent.

Description

technical field [0001] The invention is a new technology system for screening and establishing a pure line of disease-resistant grass carp with excellent production performance. Background technique [0002] Grass carp is the main freshwater aquaculture fish in my country, and occupies an important position in China's aquaculture industry and national economy. However, in the artificial cultivation of grass carp, the diseases of the first and second-year-old grass carp are very serious, and the average survival rate of commercial fish cultivation is less than 30%, which seriously reduces the economic benefits of cultivation. [0003] Long-term studies have proved that the main cause of grass carp disease is viral, so it is difficult to find effective control drugs and methods. The currently used drug treatment methods only have a certain effect on bacterial diseases, but they will pollute the environment and reduce the quality of the grass carp cultured; the vaccination met...

AI Technical Summary

Problems solved by technology

[0004] Three-year-old grass carp rarely suffers from diseases and has strong disease resistance. This phenomenon shows that grass carp has the ability to establish a complete disease resistance system, but the establishment of grass carp disease resistance system is very complicated, and it is regulated by many different genes at different levels.

Since grass carp is a large fish with a sexual maturity cycle of up to 5 years, it will take decades or even hundreds of years to establish a pure line of disease-resistant grass carp species using this traditional genetic selection method, which consumes a lot of manpower and material resources.

Due to the scale of the breeding project, it is difficult to include all possible gene combinations, and the selected lines are likely to disappear due to inbreeding depression, and the breeding goals cannot be achieved