Insights into the genetic architecture of sexual dimorphism from an interspecific cross between two diverging Silene (Caryophyllaceae) species

The evolution of sexual dimorphism in species with separate sexes is influenced by the resolution of sexual conflicts creating sex differences through genetic linkage or sex-biased expression. Plants with different degrees of sexual dimorphism are thus ideal to study the genetic basis of sexual dimorphism. In this study we explore the genetic architecture of sexual dimorphism between Silene latifolia and S. dioica. These species have chromosomal sex determination and differ in the extent of sexual dimorphism. To test whether QTL for sexually dimorphic traits have accumulated on the sex chromosomes and to quantify their contribution to species differences, we create a linkage map and performed QTL analysis of life history, flower and vegetative traits using an unidirectional interspecific F2 hybrid cross. We found support for an accumulation of QTL on the sex chromosomes and that sex differences explained a large proportion of the variance between species, suggesting that both natural an...

具有雌雄异株特性的物种，其性二态性（sexual dimorphism）的演化进程，会受到通过遗传连锁或性别偏向性表达来解决性冲突、进而催生性别差异的机制调控。因此，拥有不同程度性二态性的植物，是探究性二态性遗传基础的理想研究体系。本研究聚焦于白玉草（Silene latifolia）与迪氏麦瓶草（S. dioica）之间的性二态性遗传架构；这两个物种均采用染色体性别决定机制，且性二态性的表现程度存在显著差异。为验证控制性二态性状的数量性状位点（QTL）是否在性染色体上发生富集，并量化其对物种间表型差异的贡献，本研究构建了遗传连锁图谱，并通过单向种间F2杂交群体，对生活史、花部及营养性状开展QTL分析。研究发现，性染色体上确实存在QTL富集现象，且性别差异可解释物种间大部分的表型变异，这表明自然（原文后续内容未完整给出）。