星斑川鲽家系建立及遗传效应分析

The family lines establishment and genetic effects analysis of the starry flounder Platichthys stellatus

星斑川鲽是优良的鲆鲽鱼类种质之一,在鲆鲽鱼类养殖产业中具有重要的地位。本研究初次收集了分布于山东半岛的4个养殖群体（日照、胶南、威海和蓬莱）的350尾亲鱼,分别测量了100尾雌雄亲鱼的体长和体质量,拟合了雌雄性亲鱼体质量和体长幂函数关系,分别为：y=0.034 2x2.843 6（R2=0.565）和y=0.075 9x2.533 4（R2=0.753 8）。利用其中成熟的55尾雄鱼和46尾雌鱼进行人工繁殖,雌鱼平均产卵次数为4.39次、雄鱼产精次数为2.36次。其中25个杂交组合繁殖成功,建立了29个半同胞和全同胞家系。在家系生长到150d时,对1 640尾鱼苗体质量、全长、体长和体宽4个性状进行测量。利用最小范数二次无偏估计法（MINQUE）对以上性状的方差组分进行估计,利用＂加-显性＂模型对生长性状遗传力进行估计,采用线性无偏预测法（Linear Unbiased Prediction,LUP）预测亲本的加性和显性遗传效应。结果显示：4个性状的遗传相关系数为0.809～0.999（P〈0.01）。体质量、全长、体长和体宽4个性状的加性、显性方差分量都达到极显著水平（P〈0.01）,狭义遗传率为0.311～0.444（P〈0.01）,广义遗传率为0.377～0.525（P〈0.01）。加性遗传效应预测显示：31个亲本中的6个在4个性状上同时具有极显著的正向效应（P〈0.01）,10个亲本具有极显著（P〈0.01）或显著（P〈0.05）的负向效应。显性随机效应预测显示：25个杂交组合中6个具极显著正向效应（P〈0.01）,8个具有极显著负向效应（P〈0.01）。研究结果首次为星斑川鲽家系建立和优良苗种培育筛选出了优良的亲本和杂交组合,同时为星斑川鲽的选择育种提供了丰富的遗传指标。

The starry flounder Platichthys stellatus is one of the superior flatfish species in China and occupies an important place in flatfish aquaculture.350 brood fish consisting of 4cultural populations were collected from Shandong Peninsula（Rizhao,Jiaonan,Weihai and Penglai）.The body length and weight of 100 male and female brood fish were measured.The relationship of the power function between body length and weight was fitted as y=0.034 2x2.843 6（R2=0.565）（female）and y=0.075 9x2.533 4（R2=0.753 8）（male）.55 male and 46 female fish were used for artificial reproduction with 4.39 times spawning and 2.36 times spermatogenesis.There were 25 successful cross combinations,which reproduced 29half-sib families and full-sib families.After 150-day culture,the weight,full length,body length and width of 1 640 fries were measured.Variance components were evaluated by using the minimum norm quadratic unbiased estimator（MINQUE）.Heritability of growth-related traits was estimated by using additive-dominance model.Heritability（additive and dominant genetic effects）was predicted by using linear unbiased prediction（LUP）.Results showed that the genetic correlations among four traits were 0.809-0.999（P〈0.01）and variance components of their additive and dominant genetic effects were significantly different（P〈0.01）.Narrow heritability was 0.311-0.444（P〈0.01）,while broad heritability was 0.377-0.525（P〈0.01）.Additive genetic effects analysis showed that 6of 31 parents were extremely significantly positive in these 4traits（P〈0.01）,while 10 parents were extremely significantly（P〈0.01）or significantly negative（P〈0.05）.Dominant random effects analysis showed that 6of 25 cross combinations were extremely significantly positive（P〈0.01）,while 8were extremely significantly negative（P〈0.01）.All these results first provided abundant genetic data for the selection of good parents and cross combinations in the family lines establishment and seed culture of the starry flounder.