Among-year variation in selection during early life stages and the genetic basis of fitness in Arabidopsis thaliana

Incomplete information regarding both selection regimes and the genetic basis of fitness limits our understanding of adaptive evolution. Among-year variation in the genetic basis of fitness is rarely quantified, and estimates of selection are typically based on single components of fitness, thus potentially missing conflicting selection acting during other life-history stages. Here, we examined among-year variation in selection on a key life-history trait and the genetic basis of fitness covering the whole life cycle in the annual plant Arabidopsis thaliana. We planted freshly-matured seeds of >200 recombinant inbred lines (RILs) derived from a cross between two locally-adapted populations (Italy and Sweden), and both parental genotypes at the native site of the Swedish population in three consecutive years. We quantified selection against the nonlocal Italian genotype, mapped quantitative trait loci (QTL) for fitness and its components, and quantified selection on timing of germinat...

对于选择模式（selection regimes）与适合度（fitness）遗传基础的认知缺口，制约了我们对适应性进化的理解。适合度遗传基础的年际变异极少被量化，而选择强度的估计通常仅基于适合度的单一组分，因此可能遗漏了在其他生活史阶段发挥作用的冲突性选择。本研究以一年生植物拟南芥（Arabidopsis thaliana）为研究对象，探究了关键生活史性状所受选择的年际变异，以及覆盖全生活史周期的适合度遗传基础。我们连续三年在瑞典种群的原生境中，种植了由两个本地适应种群（意大利种群与瑞典种群）杂交得到的200余个重组自交系（recombinant inbred lines, RILs）的新鲜成熟种子，以及两个亲本的基因型材料。我们量化了针对非本地意大利基因型的选择强度，定位了适合度及其组分的数量性状位点（quantitative trait loci, QTL），并量化了萌发时间所受的选择……