摘要
综述了多倍体贝类的生物学特性。由于诱导剂的毒性作用或致死基因纯合等原因，多倍体贝类在胚胎及幼虫期的存活率明显低于正常二倍体，但在成体期间则差异不明显。一般认为三倍体由于其不育性而比二倍体生长速度快，个体大，品质好。然而，三倍体并非完全不育，在繁殖期间性腺也有一定程度的发育，能够产生少量体积较大的精卵；在大多数诱导的多倍体贝类中，雌雄比例与二倍体是接近的；多倍体贝类的抗逆性并不高于二倍体，在恶劣环境条件下，三倍体的生长及存活能力甚至低于正常二倍体；三倍体贝类的耗氧率、氨氮排泄率以及生化组成等与二倍体无明显差异；在繁殖季节，三倍体的醣原含量明显高于二倍体，其能量收支处于正平衡，而二倍体则处于负平衡。
The biological characteristics of polyploid shellfish are reviewed in this paper. The survival rate of polyploid shellfish at embryo and larval stage is significantly lower than that of diploid because of the toxicity of the inducer or the expression of lethal recessive genes due to high levels of homozygosity. But there is no significant difference between the survival of diploids and triploids at adult stage. It is commonly considered that triploid shellfish grow faster than diploid and have better quality because of sterility. However, triploids are not absolutely sterile, their gonads can develop to a certain extent in the reproductive season, and produce a small quantity of larger eggs and sperm. In most induced polyploid shellfish, the sex ratio of the male and female is nearly the same as that of diploid. Little is known about sex determination. The growth and survival ability of triploid is even lower than that of diploid in bad condition. There is no significant difference between diploid and triploid in rates of oxygen consumption and ammonia excretion and biochemical content, but the glycogen content of triploids is much higher than that of diploids in the reproductive season. Ripe yearling diploids are in negative energy balance while triploid siblings remain in a state of positive energy balance.
基金
国家高技术发展计划
关键词
贝类
多倍体
生物学特性
shellfish
polyploid
biological characteristics
