三疣梭子蟹生长性状的遗传力评估

Estimates for the Heritability of Economically Important Growth-traits in Portunus trituberculatus

准确可靠的遗传力是育种实践的前提,本研究采用不平衡巢式设计和室内定向交尾技术完成亲蟹交配,交配模式为1个雄性三疣梭子蟹配3个雌性三疣梭子蟹,建立100组上述交配组合;经过交尾、越冬,次年春天成功构建了37个三疣梭子蟹全同胞家系,其中13个半同胞家系;80和120日龄时每个家系随机选取30个左右个体,测量其全甲宽、甲长、体高3个生长性状。通过SPSS 11.5一般线性模型（GL.M）,计算表型变量的方差组分,评估全甲宽、甲长、体高等重要经济性状的遗传力。结果表明,三疣梭子蟹80日龄3项生长性状总平均值分别为（77.99±11.42）、（35.90±5.84）、（20.13±7.77）mm,80日龄遗传力估计值为0.51-0.69;120日龄3项生长性状总平均值分别为（122.73±12.80）、55.（13±5.39）、（29.99±3.34）mm,120日龄遗传力估计值在0.27-0.70之间。通过t检验发现只有基于全同胞方差组分估计的遗传力达到极显著水平,而基于母系半同胞、父系半同胞方差组分估计的遗传力均未达到显著水平。因此三疣梭子蟹2个发育阶段狭义遗传力的无偏估计值为全同胞方差组分估计的遗传力,估计值分别为0.53-0.60和0.45-0.50。研究结果表明三疣梭子蟹3项重要经济性状属于高度遗传力,说明对其选择具有较大的潜力。

In China,farming of P.trituberculatus produces annual yields of up to 100 000 tons.With the expansion and intensification of P.trituberculatus,various questions such as diseases,bad quality of larvas and less natural resources,have occurred and been serious,causing economic losses.At last,these questions are resolved by provided excellent breeds provided by using the selecting breeding program.It is an important way of selecting breeding.We must know the heritability of the species,first.So,the heitability of economic traits in P.trituberculatus were estimated by means of intra group correlation of full-sibs on day 80 and 120.A total of 400 maturing crab were from the base populations,which was established at the Yellow Sea Fisheries Research Institute using four wild,geographically distinct,Chinese populations（Laizhou Gulf,Zhousha,Yalvjiangkou,and Haizhou Gulf）.One hundred sires and three hundred dams were mated by 1♂ ×3♀,producing 37full-sib families including 13 halfsib families.Families were hatched and reared separately under identical conditions until they reached the second crab stage.The outdoor pond was divided with netting into several equally-sized ponds and a total of 1 500randomly-selected second-stage crabs from each family were moved to these separate small ponds.Families were reared and managed under identical conditions of feeding and drug administration.The full carapace width,carapace length,body height of about 30 individuals from each family were measured on 80 and 120days.Causal components of phenotypic variance were calculated with the GLM procedure of SPSS software.The results showed full carapace width,carapace length,body height on day 80 and 120of age were（77.99±11.42）,（35.90±5.84）,（20.13±7.77）and（122.73±12.80）,（55.13±5.39）,（29.99±3.34）mm respectively.The heritabilities of economic traits on day 80 and 120of age 0.51-0.69 and 0.27-0.70 respectively.There were no significant difference in heritabilities estimates obtained from maternal and paternal genetic variance.But there was significant difference in heritability estimates obtained from components of variance of full-sibs within sires and dams.So it was concluded that heritability estimates（0.53-0.60,0.45-0.50）obtained from components of variance of full-sibs within sires and dams were precise and unbiased for body weight on day 80 and 120,which suggested that the heritabilities of growth traits（e.g.,full carapace width,carapace length,body height）were high.