Genomic Selection
Genomic Selection
复制标题
DOI：
10.1007/978-81-322-2316-0_10
复制
发表时间：
2022
期刊：
影响因子：
--
通讯作者：
Shizhong Xu
中科院分区：
文献类型：
--
作者：
Shizhong Xu
标记辅助选择(MAS)非常适合处理效应较大的寡基因和数量性状基因座(QTL)。分子标记辅助选择主要用于回交育种，包括有用基因/QTL的聚合和标记辅助轮回选择(MARS)。大多数数量性状的表达受一个或几个效应较大的QTL和几个效应较小的QTL控制。因此，MAS和MARS方案不适用于数量性状的改良，因为它们不能处理效应小的QTL。基因组选择(GS)方案就是为了弥补MAS和MARS方案的不足而提出的。GS方案是MAS的一种特殊形式，它利用来自全基因组标记数据的信息，无论它们与相关性状(S)的关联是否显著。GS方案使用训练群体来估计标记对目标性状的影响，并训练GS模型。然后，GS模型被用于根据育种群体的标记基因类型来计算育种群体的植株/品系的基因组估计育种价值(GEBV)。然后，这些GEBV估计值被用作选择优势植株/品系的基础。GS方案可以有效地利用反季节苗圃和温室设施，加快育种进程，对复杂性状的选择非常有效。本章描述了GS方案的各个方面，并讨论了它在异花授粉和自花授粉物种改良中的应用。
Marker-assisted selection (MAS) is well suited for handling oligogenes and quantitative trait loci (QTLs) with large effects. MAS has been extensively used mainly for backcross breeding, including pyramiding of useful genes/QTLs, and for marker-assisted recurrent selection (MARS). The expression of most quantitative traits is governed by one or few QTLs with relatively large effects along with several QTLs with small effects. Thus, MAS and MARS schemes are not well suited for the improvement of quantitative traits since they cannot handle QTLs with small effects. The genomic selection (GS) scheme was proposed to rectify this deficiency of MAS and MARS schemes. The GS scheme is a specialized form of MAS that utilizes information from genome-wide marker data whether or not their associations with the concerned trait(s) are significant. GS scheme uses a training population to estimate the effects associated with the marker on the target trait and to train the GS model. The GS model is then used to calculate the genomic estimated breeding values (GEBVs) of the plants/lines of the breeding population on the basis of their marker genotypes. These GEBV estimates are then used as the basis of the selection of the superior plants/lines. The GS scheme can make effective use of off-season nursery and greenhouse facilities to accelerate the breeding program and is quite effective in selection for the complex traits. This chapter describes the various aspects of the GS scheme and discusses its applications for the improvement of both cross- and self-pollinated species.