Yoko Zebadiah G, Volk Kate L, Dochtermann Ned A, Hamilton Jill A
Department of Biological Sciences, North Dakota State University, Fargo, ND, USA.
AoB Plants. 2020 Mar 7;12(2):plaa009. doi: 10.1093/aobpla/plaa009. eCollection 2020 Apr.
For widely distributed species, understanding the scale over which genetic variation correlates to landscape structure and composition is critical. Particularly within the context of restoration, the evolution of genetic differences may impact success if seeds are maladapted to the restoration environment. In this study, we used to quantify the scale over which genetic differences for quantitative traits important to adaptation have evolved, comparing the proportion of variance attributed to broad regional- and local population-level effects. is a widely distributed species spanning a range of environments, including alvar and prairie habitats, which have extreme regional differences in soil-moisture availability. Alvar habitats are regions of thin soil over limestone that experience substantial seasonal variation in water availability, from flooding to desiccation annually. This contrasts with prairie habitats, whose deeper soils mitigate irregular flood-desiccation cycles. Using a common garden experiment, we evaluated 15 traits broadly grouped into three trait classes: resource allocation, stomatal characteristics, and leaf morphological traits for individuals sourced from prairie and alvar environments. We quantified the proportion of trait variance explained by regional- and population-scale effects and compared the proportion of regional- and population-trait variances explained across trait classes. Significant regional differentiation was observed for the majority of quantitative traits; however, population-scale effects were equal or greater than regional effects, suggesting that important genetic differences may have evolved across the finer population scale. Stomatal and resource allocation trait classes exhibited substantial regional differentiation relative to morphological traits, which may indicate increased strength of selection for stomatal and resource allocation traits relative to morphological traits. These patterns point towards the value in considering the scale over which genetic differences may have evolved for widely distributed species and identify different functional trait classes that may be valuable in establishing seed transfer guidelines.
对于分布广泛的物种而言，了解遗传变异与景观结构和组成相关的尺度至关重要。特别是在恢复的背景下，如果种子对恢复环境适应不良，遗传差异的演变可能会影响恢复的成功。在本研究中，我们使用[具体方法]来量化对适应重要的数量性状的遗传差异所演变的尺度，比较归因于广泛区域和当地种群水平效应的方差比例。[物种名称]是一种分布广泛的物种，跨越一系列环境，包括阿尔瓦和草原栖息地，这些栖息地在土壤水分可利用性方面存在极端的区域差异。阿尔瓦栖息地是石灰岩上薄土层的区域，每年水分可利用性经历从洪水到干燥的大幅季节性变化。这与草原栖息地形成对比，草原栖息地更深的土壤减轻了不规则的洪水 - 干燥循环。通过一个共同花园实验，我们评估了15个性状，大致分为三个性状类别：资源分配、气孔特征和来自草原和阿尔瓦环境个体的叶片形态性状。我们量化了由区域和种群尺度效应解释的性状方差比例，并比较了跨性状类别解释的区域和种群性状方差比例。对于大多数数量性状观察到显著的区域分化；然而，种群尺度效应等于或大于区域效应，这表明重要的遗传差异可能在更精细的种群尺度上已经演变。与形态性状相比，气孔和资源分配性状类别表现出显著的区域分化，这可能表明相对于形态性状，对气孔和资源分配性状选择的强度增加。这些模式指出了考虑广泛分布物种遗传差异可能演变的尺度的价值，并确定了在制定种子转移指南中可能有价值的不同功能性状类别。
