PREMISE Polyploidy may serve to contribute to range size if autopolyploid cytotypes are adapted to differing ecological conditions. This study aims to establish the geographic distribution of cytotypes within the giant goldenrod (Solidago gigantea), and to assess whether cytotypes exhibit differing ecological tolerances and morphology. METHODS A range-wide set of 629 Solidago gigantea individuals was obtained through field collecting, sampling from herbarium specimens, and incorporating existing chromosome counts. Cytotype of each unknown sample was estimated by observing allele numbers at twelve microsatellite loci, a strategy that was assessed by comparing estimated to known cytotype in 20 chromosome-counted samples. Abiotic ecological differentiation was assessed for two transitions: diploid-tetraploid and tetraploid-hexaploid. Morphological differentiation among cytotypes was assessed. RESULTS Microsatellite repeat variation accurately estimated cytotype in 85% of samples for which ploidy was known. Applying this approach to samples of unknown ploidy established that the three cytotypes are non-randomly distributed. Although niche modeling and MANOVA approaches identified significant differences in macro-climatic conditions for both cytotype transitions, the tetraploid to hexaploid transition was more substantial. Leaf length and width did not differ among cytotypes. Although leaf vestiture exhibited strong trends, no absolute differences were observed among cytotypes. CONCLUSIONS With the largest such study to date, we established niche transitions among giant goldenrod cytotypes of differing magnitudes. Collectively, this suggests that whole-genome duplication has contributed to Solidago gigantea's large range.

中文翻译：

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Solidago gigantea 中两种细胞型生态位变化的幅度不同

如果同源多倍体细胞型适应不同的生态条件，则前提多倍体可能有助于扩大范围。本研究旨在确定巨黄花（Solidago gigantea）内细胞型的地理分布，并评估细胞型是否表现出不同的生态耐受性和形态。方法 通过野外采集、植物标本馆标本取样和合并现有染色体计数，获得了 629 只大一枝花个体的范围广泛的集合。通过观察 12 个微卫星位点的等位基因数来估计每个未知样本的细胞型，该策略是通过将估计值与 20 个染色体计数样本中的已知细胞型进行比较来评估的。评估了两种转变的非生物生态分化：二倍体-四倍体和四倍体-六倍体。评估细胞型之间的形态分化。结果 微卫星重复变异准确估计了 85% 已知倍性样本的细胞类型。将这种方法应用于未知倍性的样本确定了三种细胞类型是非随机分布的。尽管生态位建模和多元方差分析方法确定了两种细胞型转变的宏观气候条件的显着差异，但四倍体到六倍体的转变更为显着。叶长和宽度在细胞型之间没有差异。尽管叶体表现出强烈的趋势，但在细胞类型之间没有观察到绝对差异。结论 通过迄今为止规模最大的此类研究，我们在不同量级的巨型金花属细胞类型之间建立了生态位转换。总的来说，