大黄鱼22个微卫星标记在F1家系中的分离方式及与生长性状的相关分析

研究了1个大黄鱼F1家系150个个体22个微卫星位点的基因型分布,并分析了标记位点与生长性状的相关性。结果显示,22个位点共检测到60个等位基因,平均等位基因数为2.73,平均有效等位基因数为2.37;平均观测杂合度与期望杂合度分别为0.75和0.73,部分位点基因型分布严重偏离孟德尔定律,暗示其可能与适应性基因相连锁,其中LYC0446位点附近可能存在隐性纯合致死基因。LYC0077位点与体质量、体长和体高均呈显著相关(P<0.05),其中等位基因A(165 bp)对应的生长性状表型值最大,可以作为选育快长性状的有效分子标记;LYC0015和LYC0243与体高呈显著相关(P<0.05),与体长、体质量的相关不显著(P>0.05),LYC0015位点的等位基因C(110 bp)和LYC0243位点的等位基因A(160 bp)为有利的等位基因。对LYC0015、LYC0077和LYC0243进行不同基因型个体表型值的多重比较,找到3种对生长性状有利的基因型,分别为BC、AA和AB。同时,以体质量性状为参照,对3个位点不同基因型组合进行比较,找到一个最优基因型组合(BC/AA/AB),与3个位点单独分析对应的最优基因型完全一致,符合加性作用模型。

The segregation patterns of 22 microsatellite markers in an F1 family of large yellow croaker(Larimichthys crocea)and correlation analysis with growth-related traits

The large yellow croaker Larimichthys crocea is one of the most important fish species in Chinese mariculture,and the research about correlation analysis between growth-related traits and microsatellite markers is very rare.In this study,the genotype distribution of twenty-two microsatellite markers was investigated in an F1 family of large yellow croaker Larimichthys crocea of 20-month old,and the correlation between growth-related traits and microsatellite markers was also analyzed using statistical method.The results are as follows:A total of 60 alleles were detected,and the average number of alleles and effective number of alleles were 2.73 and 2.37,respectively.The average observed heterozygosity(Ho)and expected heterozygosity(He)were 0.75 and 0.73,respectively.The genotype distribution of partly loci deviated severely from Mendel’s Laws,which suggested these loci might link with the adaptive gene,and LYC0446 may link with recessive homozygous lethal genes.We discovered that LYC0077 had significant impact on body weight,body length and body height(P<0.05),and the allele A(165 bp)had highest phenotype value and can be used as a molecular marker in selection breeding;LYC0015 and LYC0243 had significant impact on body height(P<0.05),and no significant effect on body length and body weight,and the allele C(110 bp)for LYC0015 and the allele A(160bp)for LYC0243 have positive effect on growth-related traits.Three genotypes of these loci with favorable effect on growth-related traits were also determined,BC for LYC0015,AA for LYC0077 and AB for LYC0243 respectively.The best genotype combinations(BC/AA/AB)for LYC0015,LYC0077 and LYC0243 were also selected according to body weight,which conformed to the Additive Effects Model.The results presented here provide a starting point for the eventual mapping of economically important genes and marker-assistant selection(MAS)in large yellow croaker.