---- Shellfish polyploid sports research direction 1 How to use efficient and economical methods to cultivate triploid seedlings, has a production value, which is what people are concerned about. At present, the induction of shellfish triploid is mainly using CB. This drug is very effective but expensive, has a variety of strong effects, and must be used with great caution. The potential impact of the use process on the environment of workers and their waste fluids is currently unable to predict the likelihood of future problems. Therefore, finding a new method that can efficiently produce triploids is an important topic for future research.
2 In triploid studies, the use of biological methods such as crossbreeding, interspecific hybridization or sperm fusion is relatively rare, and conducting research in this area is very meaningful both theoretically and practically. Tetraploids hybridize with diploids to produce triploid l00%, which has been confirmed in Pacific oysters [15]. Therefore, the breeding technology of autotetraploid shellfish has become one of the hotspots in polyploid studies. Hybridization between tetraploids and diploids is simple and efficient. It is able to efficiently and stably produce triploids and is three times more efficient. The best way of industrialization. But so far only viable tetraploids have been induced in a few species of shellfish such as Pacific oysters and mussels, and it has been difficult to induce viable tetraploids in other mussels, and how fertile autotetraploids are capable of reproduction. Whether or not a stable tetraploid strain can be established is a problem that must be solved for shellfish polyploid breeding in the future. In addition, the research on allopolyploidy is also the future development direction of polyploidy. In theory, the induction of allopolyploidy may combine the advantages of hybrid breeding and multiple breeding, expand the research field of polyploid breeding, and breed new varieties that meet people's needs. Due to the high fertility of allotetraploids, it is possible to overcome the problem of poor homogeneity of the four-fold homologous and self-reproduction of the parent population, and it is expected that the tetraploid and the diploid can be effectively crossed to solve the production of triploid seedlings. The source of the way.
3 Among the various methods for artificially inducing shellfish triploids, cold stimulation has some disadvantages in comparison with CB treatment when the triploid induction rate is similar, that is, the embryo has a higher mortality and hatching. The rate is lower, and the frequency of aneuploidy is higher, and the number of aneuploids increases with the increase of the low temperature treatment intensity. However, the cost required for cold stimulation is low and the operation is simple. If the polyploid induction rate is further increased, this method is suitable for large-scale application in production practice. Therefore, it is very necessary for in-depth research and discussion.
4 The sterility of shellfish triploid is what people expect, but there are some species. (eg, C. macrophylla and S. scallop.) Triploid gonad development is inhibited. A few individuals still have fine spermatophores and oocyte oligopod development, spermatogenesis, and egg formation, accompanied by spawning and ovulation. Fine phenomenon. Therefore, it is necessary to further study the mechanism of triploid infertility or suppressive cell production, grasp the "degree" of infertility and the period of sexual cell formation.
5 It is generally believed that the growth prominence of shellfish triploids is obvious, but triploids have no effect on longevity and survival rate, performance rules and energy distribution of growth superiority, triploidy on high water temperature, low water temperature, oxygen, and With low specific gravity tolerance, etc., the heart needs to be studied in depth.
2 In triploid studies, the use of biological methods such as crossbreeding, interspecific hybridization or sperm fusion is relatively rare, and conducting research in this area is very meaningful both theoretically and practically. Tetraploids hybridize with diploids to produce triploid l00%, which has been confirmed in Pacific oysters [15]. Therefore, the breeding technology of autotetraploid shellfish has become one of the hotspots in polyploid studies. Hybridization between tetraploids and diploids is simple and efficient. It is able to efficiently and stably produce triploids and is three times more efficient. The best way of industrialization. But so far only viable tetraploids have been induced in a few species of shellfish such as Pacific oysters and mussels, and it has been difficult to induce viable tetraploids in other mussels, and how fertile autotetraploids are capable of reproduction. Whether or not a stable tetraploid strain can be established is a problem that must be solved for shellfish polyploid breeding in the future. In addition, the research on allopolyploidy is also the future development direction of polyploidy. In theory, the induction of allopolyploidy may combine the advantages of hybrid breeding and multiple breeding, expand the research field of polyploid breeding, and breed new varieties that meet people's needs. Due to the high fertility of allotetraploids, it is possible to overcome the problem of poor homogeneity of the four-fold homologous and self-reproduction of the parent population, and it is expected that the tetraploid and the diploid can be effectively crossed to solve the production of triploid seedlings. The source of the way.
3 Among the various methods for artificially inducing shellfish triploids, cold stimulation has some disadvantages in comparison with CB treatment when the triploid induction rate is similar, that is, the embryo has a higher mortality and hatching. The rate is lower, and the frequency of aneuploidy is higher, and the number of aneuploids increases with the increase of the low temperature treatment intensity. However, the cost required for cold stimulation is low and the operation is simple. If the polyploid induction rate is further increased, this method is suitable for large-scale application in production practice. Therefore, it is very necessary for in-depth research and discussion.
4 The sterility of shellfish triploid is what people expect, but there are some species. (eg, C. macrophylla and S. scallop.) Triploid gonad development is inhibited. A few individuals still have fine spermatophores and oocyte oligopod development, spermatogenesis, and egg formation, accompanied by spawning and ovulation. Fine phenomenon. Therefore, it is necessary to further study the mechanism of triploid infertility or suppressive cell production, grasp the "degree" of infertility and the period of sexual cell formation.
5 It is generally believed that the growth prominence of shellfish triploids is obvious, but triploids have no effect on longevity and survival rate, performance rules and energy distribution of growth superiority, triploidy on high water temperature, low water temperature, oxygen, and With low specific gravity tolerance, etc., the heart needs to be studied in depth.