主基因-多基因混合遗传数量性状的单性状选择模型

Single character selective model of major gene and polygene mixed inheritance model of quantitative trait

【目的】分别估计分离世代数量性状主基因-多基因混合遗传中的多基因效应方差和环境方差,为育种工作者提供一种简单易行的单性状选择方法。【方法】利用正态分布的极限误差,将混合正态分布数据划分到多个单一正态分布对应的区间,每一区间代表一种主基因型,采用有重复观测数据的单因素多元方差分析方法,分别估计各主基因型间的主基因效应协方差阵、多基因效应协方差阵和环境协方差阵,然后结合混合正态分布中各成分分布的比例,计算该数量性状的表型方差、遗传方差、环境方差和遗传力等遗传参数,并进行实例分析。【结果】在相同选择强度下,遗传效率为110.3760%,较作为单一正态分布的普通数量性状选择效率提高了10.3760%。当选择强度i=0.5时,遗传增益GS=28.41。【结论】应用建立的主基因-多基因混合遗传数量性状单性状选择模型计算,遗传效率有很大提高,表明该方法具有实用性。

[Objective] The study was done to estimate the variance of polygene effect and environmental variance separately in the major gene and polygene mixed inheritance model of quantitative traits from segregating generation and provide a simple single character selective method for breeding operators. [Method] This paper used normal distribution＇s limit error to plot out the data of mixed normal distribution into the multiple sections which correspond single normal distribution,each section representing one major gene genotype, and the one-way analysis of variance of repeated data was applied to estimate the eovariance matrix of major gene effect among major gene genotypes, covariance matrix of polygene effect and environmental covarianee matrix, then the genetic parameters, namely the phenotypic variance, genetic variance and heritability of the quantitative trait ,were calculated combining the proportion of the component distribution of the mixed normal distribution and an example was taken to analyse. [Result] Under the same selection intensity, the genetic efficiency was 110.376 0% ,it was improved by 10. 376 0% companred with the common quantitative trait which corre-sponds single normal distribution. The genetic gain GS was 28.41 when the selection intensity was 0.5. [Conclusion] Using the single character selective model of major gene and polygene mixed inheritance model of quantitative trait to calculate, the selection efficiency was higher, showing practicability of this method.