Data from: Solidago altissima differs with respect to ploidy frequency and clinal variation across the prairie-forest biome border in Minnesota

PREMISE OF THE STUDY: Although our awareness of ploidy diversity has expanded with the application of flow cytometry, we still know little about the extent to which cytotypes within mixed-ploidy populations are genetically differentiated across environmental gradients. METHODS: To address this issue, we reared 14 populations of Solidago altissima spanning the prairie–forest ecotone in Minnesota in a common garden with a watering treatment. We assessed ploidy frequencies and measured survival, flowering phenology, and plant architectural traits for 4 years. KEY RESULTS: All populations harbored multiple cytotypes; prairie populations were dominated by tetraploids, forest populations by hexaploids. Diploids and polyploids differed significantly for 84% of the traits. Beyond average differences, the slope of trait values covaried with latitude and longitude, but this relationship was stronger for diploids than the other two polyploid cytotypes as indicated by numerous ploidy × latitude and ploidy × longitude interactions. For example, the timing of flowering of the cytotypes overlapped in populations sampled from the northeastern hemiboreal forest but differed significantly between cytotypes sampled from populations in the southwestern prairie. The watering treatments had weak effects, and there were no ploidy differences for phenotypic plasticity. CONCLUSIONS: Our data show that diploids have diverged genetically to a greater extent than polyploids along the environmental clines sampled in this study. Moreover, different environments favor phenotypic convergence over divergence among cytotypes for some traits. Differences in ploidy frequency and phenotypic divergence among cytotypes across gradients of temperature and precipitation are important considerations for restoration in an age of climate change.研究背景：尽管随着流式细胞术（Flow Cytometry）的应用，人们对倍性多样性的认知不断拓展，但我们对混合倍性种群内的细胞型在环境梯度下的遗传分化程度仍知之甚少。 材料与方法：为解决这一科学问题，我们种植了采自明尼苏达州草原-森林交错带的14个高一枝黄花（Solidago altissima）种群，设置浇水处理开展同质园（Common Garden）实验，并连续4年对其倍性频率、存活率、开花物候及植株形态性状进行测定。 主要结果：所有种群均携带多种细胞型；草原种群以四倍体（Tetraploids）为优势类群，森林种群则以六倍体（Hexaploids）占主导。二倍体（Diploids）与多倍体（Polyploids）在84%的性状上存在显著差异。除整体平均水平的差异外，性状值的变化斜率随纬度与经度呈现协同变异，但二倍体的这种关联强度显著高于另外两种多倍体细胞型，这一结论可通过大量的倍性×纬度、倍性×经度交互作用得到验证。例如，采自东北部半寒带森林的种群中，不同细胞型的开花时间相互重叠；而采自西南部草原的种群中，不同细胞型的开花时间则存在显著差异。浇水处理对性状的影响较弱，且不同倍性间的表型可塑性无显著差异。 结论：本研究数据显示，在所采样的环境梯度下，二倍体的遗传分化程度高于多倍体。此外，针对部分性状而言，不同环境更倾向于促进细胞型间的表型趋同而非分化。在气候变化时代，温度与降水梯度下的倍性频率差异及细胞型间的表型分化，是开展生态修复工作的重要考量因素。