Plant response to climate depends on a species’ adaptive potential. To address this, we used reciprocal gardens to detect genetic and environmental plasticity effects on phenotypic variation and combined with genetic analyses. Four reciprocal garden sites were planted with three regional ecotypes of Andropogon gerardii, a dominant Great Plains prairie grass, using dry, mesic, and wet ecotypes originating from western KS to Illinois that span 500–1,200 mm rainfall/year. We aimed to answer: (a) What is the relative role of genetic constraints and phenotypic plasticity in controlling phenotypes? (b) When planted in the homesite, is there a trait syndrome for each ecotype? (c) How are genotypes and phenotypes structured by climate? and (d) What are implications of these results for response to climate change and use of ecotypes for restoration? Surprisingly, we did not detect consistent local adaptation. Rather, we detected co‐gradient variation primarily for most vegetative responses. All ecotypes were stunted in western KS. Eastward, the wet ecotype was increasingly robust relative to other ecotypes. In contrast, fitness showed evidence for local adaptation in wet and dry ecotypes with wet and mesic ecotypes producing little seed in western KS. Earlier flowering time in the dry ecotype suggests adaptation to end of season drought. Considering ecotype traits in homesite, the dry ecotype was characterized by reduced canopy area and diameter, short plants, and low vegetative biomass and putatively adapted to water limitation. The wet ecotype was robust, tall with high biomass, and wide leaves putatively adapted for the highly competitive, light‐limited Eastern Great Plains. Ecotype differentiation was supported by random forest classification and PCA. We detected genetic differentiation and outlier genes associated with primarily precipitation. We identified candidate gene GA1 for which allele frequency associated with plant height. Sourcing of climate adapted ecotypes should be considered for restoration.

中文翻译：

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美国大平原气候梯度基础草原草 Andropogon gerardii 的适应性遗传潜力和性状变异的可塑性：对气候变化和恢复的影响


植物对气候的反应取决于物种的适应潜力。为了解决这个问题，我们使用互惠花园来检测遗传和环境可塑性对表型变异的影响，并结合遗传分析。四个互惠花园场地种植了三种区域生态型的仙草，一种主要的大平原草原草，使用源自堪萨斯州西部到伊利诺伊州的干燥、湿润和湿润生态型，每年降雨量为 500-1,200 毫米。我们的目的是回答：（a）遗传限制和表型可塑性在控制表型方面的相对作用是什么？ (b) 当种植在家乡时，每种生态型是否存在性状综合症？ (c) 气候如何构建基因型和表型？ (d) 这些结果对于应对气候变化和利用生态类型进行恢复有何影响？令人惊讶的是，我们没有检测到一致的局部适应。相反，我们主要检测到大多数植物反应的共同梯度变化。堪萨斯州西部的所有生态型都发育不良。向东，湿润生态型相对于其他生态型越来越强大。相比之下，适应性显示出湿和干生态型的局部适应证据，而湿和中湿生态型在堪萨斯州西部几乎不产生种子。干燥生态型的开花时间较早表明对季末干旱的适应。考虑到家园的生态型特征，干旱生态型的特点是冠层面积和直径减小、植株矮小、植物生物量低，并且可能适应水的限制。潮湿的生态型很健壮，高大，生物量高，叶子宽，被认为适合竞争激烈、光照有限的东部大平原。生态型分化得到随机森林分类和 PCA 的支持。 我们检测到主要与降水相关的遗传分化和异常基因。我们确定了候选基因 GA1，其等位基因频率与株高相关。应考虑采购适应气候的生态类型进行恢复。