Local adaptation occurs along altitudinal gradient despite the existence of gene flow in the alpine plant species Festuca eskia
Local adaptation occurs along altitudinal gradient despite the existence of gene flow in the alpine plant species Festuca eskia
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DOI：
10.1111/j.1365-2745.2009.01509.x
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发表时间：
2009-07-01
影响因子：
5.5
通讯作者：
Hazard, Laurent
中科院分区：
文献类型：
--
作者：
Gonzalo-Turpin, Heloise;Hazard, Laurent
1.高山植物物种特别容易受到气候变化的影响。因此，估计高山物种的适应潜力是至关重要的，以确定其未来的生存能力。在高山植物中，适应潜力取决于（i）种群间的海拔遗传分化，以及沿着海拔梯度的基因流动;（ii）选择性状的表型可塑性;（iii）遗传和环境对这些性状的影响之间的共梯度变异.对比利牛斯山地区常见的多年生高山禾草-羊茅（Festuca eskia Ramond）的适应潜力进行了研究。在沿着3个海拔梯度（1500 ~ 2500 m）上进行了180个个体的相互移植试验，记录了移植后的存活、功能和繁殖性状。此外，还选择了4个中性序列标记位点和简单重复序列标记来估计群体间的基因流动.尽管存在限制性基因流，但在沿着海拔梯度的种群间的所有性状中均检测到选择引起的遗传分化。对于与适合度直接相关的性状，当地海拔适应性明显。当地的适应模式表明，选择模式不同沿着海拔梯度。在低海拔地区，对生殖产量的选择占主导地位，而在高海拔地区，则观察到不同的存活率.随着海拔的升高，遗传分化导致植株高度和生殖产量降低，但比叶面积（SLA）增加。这种在更高海拔的SLA增加被解释为一种资源获取策略。在群体水平上，所有性状均表现出表型可塑性。除SLA外，所有性状的遗传分化和可塑性反应之间均存在共梯度变异，表明适应性表型可塑性在F。eskia.6.合成. F.埃斯基亚。根据海拔高度的不同，它涉及不同的适应特性。尽管存在基因流和表型可塑性，但这种分化沿着海拔梯度在小范围内发生。沿着海拔梯度遗传分化、基因流动和表型可塑性的共存为F. eskia成功适应气候变化。
1. Alpine plant species are particularly vulnerable to climate change. Therefore, estimating the adaptive potential of alpine species is of vital importance for determining their future viability. In alpine plants, adaptive potential depends on (i) altitudinal genetic differentiation among populations, combined with gene flow along an altitudinal gradient; (ii) phenotypic plasticity for the traits under selection and (iii) co-gradient variation between genetic and environmental influences on these traits.2. The adaptive potential of Festuca eskia Ramond (Poaceae), a perennial alpine grass common in the Pyrenean Mountains, was examined in this study. A reciprocal transplant experiment involving 180 individuals along three altitudinal gradients (from 1500 to 2500 m) was established, and survival, functional and reproductive traits were recorded. In addition, four neutral sequence-tagged site and simple sequence repeat molecular markers were chosen to estimate gene flow among populations.3. Genetic differentiation attributable to selection was detected in all traits between populations along the altitudinal gradient despite the existence of restricted gene flow. For traits directly related to fitness, local altitudinal adaptation was clearly evident. The patterns of local adaptation suggested that selection patterns differed along an altitudinal gradient. Selection for reproductive output was predominant at low altitudes, whereas differential survivorship was observed at higher altitudes.4. Genetic differentiation with increasing altitude resulted in reduced plant stature and reproductive output but increased specific leaf area (SLA). This increased SLA at higher altitude is interpreted as a resource acquisition strategy.5. Phenotypic plasticity was seen in all traits at the population level. Evidence of co-gradient variation between genetic differentiation and plastic response was found for all traits except SLA, suggesting that adaptive phenotypic plasticity operates in F. eskia.6. Synthesis. Local adaptation occurs in F. eskia. It involves different adaptive traits according to the altitude. Such differentiation occurs at a small scale along altitudinal gradients despite the existence of gene flow and phenotypic plasticity. The coexistence of genetic differentiation, gene flow and phenotypic plasticity along altitudinal gradients provides an adaptive potential for F. eskia to successfully adapt to climate change.