标记辅助回交育种中所需最小样本容量的近似估计

回交育种是把有利基因从供体亲本向受体亲本转移的一种有效方法，标记辅助选择可加速其进程。为了制定合理的标记辅助选择计划，育种家必须知道所需的后代群体大小。该文提出了一种估算在标记辅助回交育种中同时进行前景选择和背景选择所需群体大小的方法。在假定所需转移的目标基因座与遗传背景之间为相互独立的简化假设下，可以通过将解析方法（针对前景选择）与基于回交亲本图示基因型的模拟方法（针对背景选择）相结合，近似地估计出在每一世代中选到所需基因型的概率，进而估算出在一定概率水平下至少获得一个符合要求的个体所需的最小样本容量，用假想的例子演示了该方法的使用情况。该方法可以很方便地应用于实际的回交育种。

Approximate Estimation of Minimal Sample Size Required for Marker-Assisted Backcross Breeding

Backcross breeding is a useful method to transfer favorable alleles from a donor parent into a recipient parent.Marker assisted selection (MAS) can speed up the process.To make an appropriate plan before using MAS in a breeding program,breeders need to know the minimal sample size of the progeny generation required.A method to estimate the minimal sample size required for marker assisted backcross breeding when both foreground selection and background selection are conducted is proposed.On the basis of a simplified assumption that the target loci are introgressed and the genetic background are independent,the probability of selecting individuals with desired genotypes in each generation is approximately estimated combining analytical approach (for foreground selection) and simulation according to the graphic genotypes of backcrossing parents (for background selection).The minimal sample size required to obtain at least one desired individual with a given probability is estimated.Application of the method is demonstrated with hypothesized examples.The method can be conveniently applied to practical backcross breeding programs.