八向杂交设计的QTL区间作图方法  

Interval mapping method of QTL for eight-way cross design

作　　者：敖雁[1] 胡治球[1] 王学枫[1] 徐辰武[1] 

机构地区：[1]扬州大学江苏省作物遗传生理重点实验室,江苏扬州225009

出　　处：《扬州大学学报（农业与生命科学版）》2007年第4期36-41,共6页Journal of Yangzhou University：Agricultural and Life Science Edition

基　　金：国家自然科学基金资助项目(30270724;30370758)

摘　　要：用8个纯系亲本杂交衍生的八向杂交设计分离群体进行QTL作图的新方法,先建立八向杂交设计的数量遗传模型及其基因型的两点概率转移矩阵,以此计算基因组任一假定座位QTL基因型的条件概率;然后根据混合分布理论建立基于EM(Expectation-maximization)算法实现的QTL区间作图的极大似然估计方法。方法的有效性通过计算机模拟分析加以验证,结果表明:对于信息完全的QTL位置和效应估计的准确度和精确度,除5个QTL位置的估计均很准确外,其余均表现为样本容量越大、QTL遗传力越高,其准确度和精确度越高,表现出令人满意的结果。对于信息不完全的QTL,其统计功效未因信息不完全而受影响。此外,在该模拟设置下,标记偏分离未使QTL的统计功效、位置和效应估计的准确度和精确度显著降低。In this paper a quantitative genetic model of eight-way cross design was proposed,then the two-locus probabilities transition matrix of this design was educed and a new approach of QTL interval mapping was developed.In the study,the conditional probabilities of QTL genotypes at a putative position were first calculated by using all of marker genotypes along the chromosome;and then a maximum likelihood method implemented via EM algorithm was developed based on the theory of mixture distribution.Validity of t...

关 键 词：八向杂交设计 QTL作图 极大似然估计 EM算法 

分 类 号：S334[农业科学—作物遗传育种]