Bioclimatic regions influence genetic structure of four Jordanian Stipa species
Bioclimatic regions influence genetic structure of four Jordanian Stipa species
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DOI：
10.1111/j.1438-8677.2012.00689.x
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发表时间：
2013-09-01
期刊：
影响因子：
3.9
通讯作者：
Hensen, I.
中科院分区：
文献类型：
--
作者：
Hamasha, H. R.;Schmidt-Lebuhn, A. N.;Hensen, I.
强烈的环境梯度可以影响植物种群的遗传结构，但对于近亲物种是否对生态地理变异有相似或特殊的反应，人们知之甚少。我们分析了温度和降雨梯度对约旦4个生物气候区4种针虫种遗传结构的影响程度。利用扩增片段长度多态性（AFLP）分子标记对针茅属植物的遗传多样性、分化和结构进行了研究。对四个研究物种中的每一个，我们从不同生物气候区域的10个种群中取样120个个体，并评估了种群内和种群间的遗传多样性和遗传分化程度。广布分布的草原针茅（Stipa capensis）和小花针茅（S. parviflora）的遗传多样性高于受地理限制的半荒漠物种阿拉比卡针茅（S. arabica）和lagascae。其中3种的遗传多样性随降水量的增加而急剧下降，而随温度的升高而增加。遗传多样性主要集中在半荒漠种（S. arabica/lagascae的Phi(ST) = 0.572/0.595）和野生种（S. capensis/parviflora的Phi(ST) = 0.355/0.387）居群内。主坐标分析（PCoA）和结构分析（STRUCTURE）表明，各种针蚜种群在生态地理上呈聚类。基因组扫描显示，在特定AFLP位点上的不同选择有助于遗传分化。无论其不同的生活史，针茅物种对约旦生物气候梯度的响应相似。我们的结论是，除了主要的随机过程，陡峭的气候梯度可能塑造植物种群的遗传结构。
Strong environmental gradients can affect the genetic structure of plant populations, but little is known as to whether closely related species respond similarly or idiosyncratically to ecogeographic variation. We analysed the extent to which gradients in temperature and rainfall shape the genetic structure of four Stipa species in four bioclimatic regions in Jordan. Genetic diversity, differentiation and structure of Stipa species were investigated using amplified fragment length polymorphism (AFLP) molecular markers. For each of the four study species, we sampled 120 individuals from ten populations situated in distinct bioclimatic regions and assessed the degree of genetic diversity and genetic differentiation within and among populations. The widespread ruderals Stipa capensis and S. parviflora had higher genetic diversity than the geographically restricted semi-desert species S. arabica and S. lagascae. In three of the four species, genetic diversity strongly decreased with precipitation, while genetic diversity increased with temperature in S. capensis. Most genetic diversity resided among populations in the semi-desert species (Phi(ST) = 0.572/0.595 in S. arabica/lagascae) but within populations in the ruderal species (Phi(ST) = 0.355/0.387 S. capensis/parviflora). Principal coordinate analysis (PCoA) and STRUCTURE analysis showed that Stipa populations of all species clustered ecogeographically. A genome scan revealed that divergent selection at particular AFLP loci contributed to genetic differentiation. Irrespective of their different life histories, Stipa species responded similarly to the bioclimatic gradient in Jordan. We conclude that, in addition to predominant random processes, steep climatic gradients might shape the genetic structure of plant populations.