Data from: Among- and within-population variation in flowering time of Iberian Arabidopsis thaliana estimated in field and glasshouse conditions

The study of the evolutionary and population genetics of quantitative traits requires the assessment of within- and among-population patterns of variation. We carried out experiments including eight Iberian Arabidopsis thaliana populations (10 individuals per population) in glasshouse and field conditions. We quantified among- and within-population variation for flowering time and for several field life-history traits. Individuals were genotyped with microsatellites, single nucleotide polymorphisms and four well-known flowering genes (FRI, FLC, CRY2 and PHYC). Phenotypic and genotypic data were used to conduct QST–FST comparisons. Life-history traits varied significantly among- and within-populations. Flowering time also showed substantial within- and among-population variation as well as significant genotype × environment interactions among the various conditions. Individuals bearing FRI truncations exhibited reduced recruitment in field conditions and differential flowering time behavior across experimental conditions, suggesting that FRI contributes to the observed significant genotype × environment interactions. Flowering time estimated in field conditions was the only trait showing significantly higher quantitative genetic differentiation than neutral genetic differentiation values. Overall, our results show that these A. thaliana populations are genetically more differentiated for flowering time than for neutral markers, suggesting that flowering time is likely to be under divergent selection.

对数量性状的进化遗传学与群体遗传学开展研究，需要对群体内与群体间的变异模式进行评估。本研究在温室与田间两种实验条件下，开展了针对8个伊比利亚拟南芥（Arabidopsis thaliana）群体的实验，每个群体包含10个个体。我们对开花时间以及多项田间生活史性状的群体间与群体内变异进行了定量分析。实验个体通过微卫星（microsatellites）、单核苷酸多态性（single nucleotide polymorphisms）以及4个经典开花基因（FRI、FLC、CRY2与PHYC）进行基因分型。我们利用表型与基因型数据开展了QST-FST对比分析。生活史性状在群体间与群体内均存在显著变异；开花时间同样存在显著的群体内与群体间变异，且在不同实验条件下呈现出显著的基因型×环境互作效应。携带FRI截短变体的个体在田间条件下的个体补充率更低，且在不同实验条件下表现出差异化的开花时间表型，这表明FRI参与了观测到的显著基因型×环境互作效应。仅在田间条件下测定的开花时间，其数量遗传分化水平显著高于中性遗传分化水平。综上，本研究结果表明，相较于中性标记，这些拟南芥群体在开花时间性状上的遗传分化程度更高，这暗示开花时间很可能受到了歧化选择的作用。