二花脸猪和大白猪产仔数加性—显性遗传模型以及基因效应的研究

对二花脸猪，大白猪及其杂交一代和回交一代4种群体共计2010窝产仔数的资料进行了加性一显性遗传模型以及基因效应的研究，方差分析结果显示，窝产仔数（总产仔数和活产仔数）具有极显的群体间差异，表明不同群体的遗传结构不同，多元回归结果表明：加性效应平方和占总产仔数和活产仔数总遗传变异平方和的比较分别为75．4％和69．8％，可见加性效应是群体间遗传变 异的主导因素，显性效应平方和占总仔数和活产仔数总遗传变异平方和的比例分别为18．3％和23．7％，表明显性效应在群体间遗传变异中是相当重要的，上位效应平方和点总产仔数和活产仔数总遗传变异平方和的比例分别为6．3％和6．5％，可见上位效应对窝产仔群体间遗传差异作用不大，猪总产仔数和活产仔数的群体平均值分别为13．01和12．42，二花脸猪总仔数和活产仔数基因加性值比大白猪分别高2．77和2．49头，二花脸猪高的总产仔数和活产仔数基因对大白猪等位基因均为显性，显性度分别为0．91和0．97，适合性检验结果表明，窝产仔数符合加性一显性遗传模式。

Study on additive-dominant genetic model and gene effects on litter size in Erhualian pigs and Large White

Study on additive dominant genetic model and gene effects was conducted on the data of 4 populations with 2 010 litters including Erhualian pigs(P 1),Large White(P 2),first cross(F 1)and backcross(B 2).The results of variance analysis indicated that litter size had extremely significant difference between populations,which showed that various populations had different genetic structure.The results of the multiple regression procedure showed that additive component accounted for 75 4% for the total number born,and 69 8% for the number born alive,which showed that additive effect played a leading role in the genetic variation between populations.Dominant component accounted for 18 3% for the total number born,and 23 7% for the number born alive,which showed that dominant effect was considerably important in the genetic variation between populations.Epistatic component accounted for 6 3% for the total number born,and 6 5% for the number born alive,which showed that epistatic effect was not important in the genetic variation between populations.The population means for the total number born and the number born alive were 13 01 and 12 42,respectively.The additive effects of the genes on the total number born and the number born alive in Erhualian pigs were 2 77 and 2 49 higher than the corresponding allele in Large White.The genes on the total number born and the number born alive in Erhualian pigs were dominant to the corresponding allele in Large White with the degree of dominance of 0 91 and 0 97.The results of fitness test indicated that additive dominant genetic model was adequate for litter size.