Data from: Local adaptation, phenotypic differentiation and hybrid fitness in diverged natural populations of Arabidopsis lyrata

Selection for local adaptation results in genetic differentiation in
ecologically important traits. In a perennial, outcrossing model plant
Arabidopsis lyrata, several differentiated phenotypic traits contribute to
local adaptation, as demonstrated by fitness advantage of the local
population at each site in reciprocal transplant experiments. Here we
compared fitness components, hierarchical total fitness and
differentiation in putatively ecologically important traits of plants from
two diverged parental populations from different continents in the native
climate conditions of the populations in Norway and in North Carolina
(NC), USA. Survival and number of fruits per inflorescence indicated local
advantage at both sites and aster life-history models provided additional
evidence for local adaptation also at the level of hierarchical total
fitness. Populations were also differentiated in flowering start date and
floral display. We also included reciprocal experimental F1 and F2 hybrids
to examine the genetic basis of adaptation. Surprisingly, the F2 hybrids
showed heterosis at the study site in Norway, likely because of a
combination of beneficial dominance effects from different traits. At the
NC site, hybrid fitness was mostly intermediate relative to the parental
populations. Local cytoplasmic origin was associated with higher fitness,
indicating that cytoplasmic genomes also may contribute to the evolution
of local adaptation.

针对本地适应的选择会导致具有生态重要性的性状产生遗传分化。在多年生异交模式植物岩生拟南芥（Arabidopsis lyrata）中，多项分化的表型性状共同促成了本地适应——互惠移植实验已证实，各站点的本地种群均具备适合度优势。本研究对比了来自不同大陆的两个分化亲本种群的适合度组分、层级总适合度，以及疑似具有生态重要性的性状差异，实验分别在两个种群的原生气候条件下开展：一处为挪威的种群原生境，另一处为美国北卡罗来纳州（NC）的种群原生境。存活率及每花序的果实数均表明，两个站点的本地种群均具有适合度优势；aster生活史模型为层级总适合度层面的本地适应提供了额外佐证。两个亲本种群在开花始期与花展示性状上同样存在分化。本研究还纳入了互惠实验得到的F1及F2代杂交种，以探究适应的遗传基础。令人意外的是，F2代杂交种在挪威的实验站点表现出杂种优势，这可能源于不同性状的有益显性效应共同作用。而在NC站点，杂交种的适合度大多介于两个亲本种群之间。本地细胞质来源与更高的适合度相关联，这表明细胞质基因组同样可能参与本地适应的演化过程。