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作物在长期进化过程中,除自然选择外,还经历了两次大的人工选择,即人工驯化选择和育种选择,使栽培种与野生种之间、现代品种与古老的地方品种之间在群体遗传结构及性状上形成了很大的差异;在基因组中,一些承受强选择作用的基因在群体中的多样性显著降低,同时这些基因附近区域的遗传多样性也明显下降。在遗传学中将这种对个别基因的选择导致其侧翼区域遗传多样性降低的现象称之为选择牵连效应(Hitchhikingeffect,也称选择搭载效应)。通过大群体多位点的扫描分析,可找到一些发生选择牵连效应的基因组区段,利用标记/性状关联分析(Marker/Traitassociationanalysis),就可发现这些区段所控制的重要性状;对这些区段进行精细扫描和分析,即可找到一些决定重要农艺性状的基因,并发现优异等位变异,从而为重要基因的克隆和作物品种的分子设计奠定基础。各大作物高密度分子标记连锁图谱的绘制完成、高通量基因型分析技术体系的建立,为利用选择牵连效应分析、通过标记/性状之间的关联,寻找和定位一些重要基因奠定了基础。本文在查阅文献的基础上,结合作者的研究,以小麦株高、千粒重、磷的吸收和利用等性状为例,就选择牵连效应分析的基本思路、方法进行了讨论,以起到抛砖引玉之作用。
In the course of long-term evolution of crops, in addition to natural selection, it has also undergone two major artificial choices, that is, artificial domestication and breeding options, so that between cultivars and wild species, between modern varieties and ancient landraces, Genetic structure and traits formed a very big difference; in the genome, some bear a strong selection of gene diversity in the group significantly reduced, at the same time, the genetic diversity of the vicinity of these genes also decreased significantly. In genetics, the selection of individual genes leads to the reduction of the genetic diversity of the flanking regions. This is called the selective bridging effect (Hitchhikingeffect). A large group of multi-loci scans can be used to find out some genomic segments in which selection-induced effects occur. Marker / Traitassociation analysis can identify important traits controlled by these segments. For these segments Fine scanning and analysis can find genes that determine important agronomic traits and find excellent allelic variations that lay the foundation for the cloning of important genes and the molecular design of crop varieties. The mapping of high-density molecular marker linkage map of major crops was completed. The establishment of high-throughput genotyping technology system laid the foundation for finding and locating some important genes by means of the selection-induced effect analysis through the association between markers / traits. Based on the literature review and the author’s study, this paper takes the wheat plant height, 1000-grain weight, phosphorus uptake and utilization as an example to discuss the basic ideas and methods of selecting implicated effect analysis in order to promote .