基于多态基因座位的数量性状遗传方差估计

对数量性状基于多态位点的遗传变异进行了研究，并给出了其方差组分的估计方法。数量性状相对多态座位的加性方差和遗传性方差分别为VA=2βp和VG＝p′Xp－G^2，其中p′和p分别表示多态等位基因频率的行向量和列向量，X表示以基因型值平方为元素的矩阵，β表示以基因均效平方为元素的行向量，G为群体均数。纯合子效应等于零时，利用最小二乘分析从观察值中估计多态座位的基因型值。对皖南花猪的主要经济性状基于多态座位的方差组分进行了估计和分析，结果显示Tf和Am座位对繁殖性状变异的影响微弱。6－PGD座位是影响肌肉的pH（VA为主导）和日增重（VD为主导）性状变异的重要座位；PO2是影响肉嫩度、失水率、pH和日增重性状变异的重要座位，并且对日增重和失水率是以加必方差为主导，而对嫩度是以显性方差为主导；除肌肉的嫩度外，PHI对胴体品质性状的变异的影响较小。

Estimation of Genetic Variance of Quantitative Trait Based on Polymorphic Gene Locus

Based on polymorphic gene locus, a plan to analyze the genetic variation of quantitative trait has been found in this paper. At polymorphic gene locus, the variance components of quantitative trait was described as follows：VA=2βp and VG=p′Xp-G2 in which p=column vector of polymorphic allele frequencies,β=row vector of (gene average effect)2,X=［a2ij］i×i matrix,aij=genotype value,and G=population mean (deviation).The genotypic value from the observed value of quantitative trait was estimated by least square model with the restriction Σ(aii)=0.The variance components of some quantitative traits were estimated based on serum enzyme Tf,Amy, 6-PGD,PHI,and Postalbumin-2 (PO2) loci.The results showed that the effects of Tf and Am locus to reproductive traits and carcass quality characters were faintness. The 6-PGD loci was very important in the effect on the variation of meat pH (dominated by VA) and daily gain (dominated by VD).The PO2 locus was also important in the effect on tenderness, water-holding capacity,pH and daily gain.The leading variation was VD in PO2 to meat tenderness, compared with VA to daily gain and water-holding capacity. The effect of PHI locus to carcass character variation, but to tenderness, was faintness.