Knotek Adam, Konečná Veronika, Wos Guillaume, Požárová Doubravka, Šrámková Gabriela, Bohutínská Magdalena, Zeisek Vojtěch, Marhold Karol, Kolář Filip
Department of Botany, Charles University, Prague, Czechia.
Institute of Botany, The Czech Academy of Sciences, Průhonice, Czechia.
Front Plant Sci. 2020 Dec 8;11:561526. doi: 10.3389/fpls.2020.561526. eCollection 2020.
Parallel evolution provides powerful natural experiments for studying repeatability of evolution and genomic basis of adaptation. Well-documented examples from plants are, however, still rare, as are inquiries of mechanisms driving convergence in some traits while divergence in others. , a predominantly foothill species with scattered morphologically distinct alpine occurrences is a promising candidate. Yet, the hypothesis of parallelism remained untested. We sampled foothill and alpine populations in all regions known to harbor the alpine ecotype and used SNP genotyping to test for repeated alpine colonization. Then, we combined field surveys and a common garden experiment to quantify phenotypic parallelism. Genetic clustering by region but not elevation and coalescent simulations demonstrated parallel origin of alpine ecotype in four mountain regions. Alpine populations exhibited parallelism in height and floral traits which persisted after two generations in cultivation. In contrast, leaf traits were distinctive only in certain region(s), reflecting a mixture of plasticity and genetically determined non-parallelism. We demonstrate varying degrees and causes of parallelism and non-parallelism across populations and traits within a plant species. Parallel divergence along a sharp elevation gradient makes a promising candidate for studying genomic basis of adaptation.
平行进化为研究进化的可重复性和适应的基因组基础提供了有力的自然实验。然而，来自植物的有充分记录的例子仍然很少，对某些性状趋同而另一些性状分化的驱动机制的探究也很少。，一种主要分布在山麓的物种，在高山地区有形态上不同的分散分布，是一个很有前途的候选对象。然而，平行性假说仍未得到验证。我们在所有已知有高山生态型的地区对山麓和高山种群进行了采样，并使用单核苷酸多态性（SNP）基因分型来测试重复的高山定殖情况。然后，我们结合实地调查和一个共同花园实验来量化表型平行性。按区域而非海拔进行的遗传聚类以及溯祖模拟表明，高山生态型在四个山区有平行起源。高山种群在高度和花部性状上表现出平行性，这种平行性在种植两代后仍然存在。相比之下，叶部性状仅在某些区域有差异，这反映了可塑性和基因决定的非平行性的混合。我们证明了一个植物物种内不同种群和性状的平行性和非平行性的不同程度及原因。沿着陡峭海拔梯度的平行分化使成为研究适应的基因组基础的一个有前途的候选对象。
