Laboratoire de Génétique et Evolution des Populations Végétales, UMR CNRS 8016, Université des Sciences et Technologies de Lille, Bâtiment SN2, F-59655 Villeneuve d'Ascq Cedex, France.
New Phytol. 2010 Jan;185(1):130-42. doi: 10.1111/j.1469-8137.2009.03062.x. Epub 2009 Oct 23.
We estimated the level of quantitative polymorphism for zinc (Zn) tolerance in neighboring metallicolous and nonmetallicolous populations of Arabidopsis halleri and tested the hypothesis that divergent selection has shaped this polymorphism. A short-term hydroponic test was used to capture the quantitative polymorphism present between edaphic types, among and within populations. We measured six morphological and physiological traits on shoots and roots to estimate the response of A. halleri to Zn. In order to assess the adaptive value of Zn tolerance polymorphism, we compared differentiation of quantitative traits with that of molecular markers. Zinc tolerance of metallicolous populations was, on average, higher than that of nonmetallicolous populations according to the morphological and physiological traits measured. Phenotypic variability within edaphic types was very high and mainly explained by polymorphism among individuals within populations. Genetic differentiation for photosystem II yield of leaves (a measure of photosynthetic efficiency) was greater than the differentiation for microsatellite and thus, probably shaped by divergent selection. Overall, these results suggest that, in the sampled populations, Zn tolerance has been increased in metallicolous populations through selection on standing genetic variation within local nonmetallicolous ancestral populations.
我们估计了拟南芥近缘种金属矿区和非金属矿区种群锌（Zn）耐性的定量多态性水平，并检验了选择是否导致了这种多态性的形成。我们采用短期水培试验来捕获土壤类型、种群内和种群间存在的定量多态性。我们测量了地上部和根部的六个形态和生理性状，以估计 A. halleri 对 Zn 的响应。为了评估 Zn 耐性多态性的适应价值，我们比较了定量性状的分化与分子标记的分化。根据所测量的形态和生理性状，金属矿区种群的 Zn 耐性平均高于非金属矿区种群。土壤类型内的表型变异性非常高，主要由个体间的多态性解释。叶片的光合系统 II 产量（衡量光合作用效率的指标）的遗传分化大于微卫星的分化，因此可能是由分歧选择形成的。总的来说，这些结果表明，在所采样的种群中，金属矿区种群的 Zn 耐性是通过对当地非金属矿区祖先种群的遗传变异进行选择而增加的。
