Pre-adaptation to climate change through topography-driven evolution of traits and their plasticity

Phenotypic data were collected in a glasshouse, in which Fragaria vesca plants originating from 11 locations were subjected to three episodes of three soil moisture treatments. The phenotypic variables include dried above-ground biomass, specific leaf area (SLA), the total number of runners produced during the second episode soil moisture treatment (counted and cut each week), number of stomata, and total number of flowers during a third episode of soil moisture treatments. SLA was measured for the most representative leaf per plant (i.e. average in size), as the ratio of “leaf area / dried leaf mass”. Stomata were counted on nail polish leaf prints using a KEYENCE light microscope at 1000 x magnification. For three replicate counts per leaf print, median stomatal density instead of averages were used to minimize the impact of counting errors. We did not measure stomatal size because image quality was insufficient for accurate size estimates. To disconnect runner and flower formation from growth, we divided runner and flower numbers by biomass. Thus, runnering and flowering were expressed per unit dry biomass (g). As a proxy for potential maternal effects, dry above-ground biomass was measured during the first soil moisture treatment (early growth).

本研究的表型数据采集于温室，供试的森林草莓（Fragaria vesca）植株源自11个采样点，所有植株均接受了三轮处理，每轮包含三种不同的土壤水分条件。本次测定的表型性状包括地上部分干生物量、比叶面积（specific leaf area, SLA）、第二轮土壤水分处理周期内产生的总匍匐茎数（每周计数并剪除）、气孔数量，以及第三轮土壤水分处理周期内的总开花数。比叶面积以单株最具代表性的叶片——即大小处于平均水平的叶片——为测量对象，计算式为叶面积与干叶质量的比值。气孔计数采用指甲油印迹法，使用基恩士（KEYENCE）光学显微镜以1000倍放大倍率进行观测。每份叶片印迹进行三次重复计数，最终采用气孔密度的中位数而非平均值，以最大程度降低计数误差的影响。由于图像质量不足以支持精准的气孔尺寸估算，因此未测定气孔大小。为消除植株生长对匍匐茎生成和开花过程的干扰，我们将匍匐茎数量和开花数除以生物量，因此匍匐茎生成量和开花量均以每克干生物量为单位进行表征。作为潜在母本效应的替代指标，我们在第一轮土壤水分处理周期（植株早期生长阶段）测定了地上部分干生物量。