主基因-多基因混合遗传分析中的EM算法  

EM Algorithm in the Analysis of Major Gene and Polygene Mixed Inheritance

作　　者：王建康[1] 盖钧镒[2] 

机构地区：[1]河南省农科院工作 [2]南京农业大学大豆研究所,南京210095

出　　处：《生物数学学报》1997年第S1期540-548,共9页Journal of Biomathematics

基　　金：国家高新技术863资助

摘　　要：大量试验数据和QTL作图结果表明：控制数量性状的基因中既有遗传效应较大的主基因，又有遗传效应较小的多基因，其分离世代表现出多峰性，即出现多个分布混合的特征．本文研究利用混合分布理论鉴定和分析主基因-多基因混合遗传模型的具体方法，推导了鉴定主基因存在和多基因存在的EM算法．以大豆开花期性状为例说明了该方法的应用，在所分析的两个杂交组合的F_2世代数据中均发现有主基因的存在、骨绿豆×泰兴黑豆杂交组合中主基因几乎不存在显性，骨绿豆×上海红芒早杂交组合中主基因（晚开花）表现出完全显性，并且有多基因存在.It has been proved by many field experiments and QTL mapping results that among genes affecting some quantitative traits there are some major genes with 1arger genetic effect and some polygenes with smaller gentic effect.For such traits,the distribution of segregating progeny demonstrates multimodality，that is the characteristic of the mixture of more than one distributions．Mixtrue distribution models have been used extensively as models in a wide variety of practical situations where data can be viewed as arising from two or more populations mixed in varying proportions，This paper shows the way to identify and analyze the major gene-polygenemixed inheritance by usiong the theory of mixture model.The EM algorithm is deduced for identi-fying the existance of major genes in F_2 population．Under the existance of major genes，the EM algorithm for identifying the existance of polygene is also educed．In the end，inheritance of soyhean flowering date was analyzed.Major genes were all found in the two F_2 populations derived by Guludou×Taishingheidou and Guludo×Shanghaihongmangzao．

关 键 词：主基因-多基因混合遗传 混合模型 极大似然估计 EM算法 

分 类 号：Q348[生物学—遗传学]