Botanic Gardens Conservation International, 1000 Lake Cook Road, Glencoe, IL 60022, USA.
Am J Bot. 2011 Jan;98(1):109-21. doi: 10.3732/ajb.1000229. Epub 2010 Dec 23.
Despite rapid growth in the field of landscape genetics, our understanding of how landscape features interact with life history traits to influence population genetic structure in plant species remains limited. Here, we identify population genetic divergence in three species of Penstemon (Plantaginaceae) similarly distributed throughout the Great Basin region of the western United States but with different pollination syndromes (bee and hummingbird). The Great Basin's mountainous landscape provides an ideal setting to compare the interaction of landscape and dispersal ability in isolating populations of different species.
We used eight highly polymorphic microsatellite loci to identify neutral population genetic structure between populations within and among mountain ranges for eight populations of P. deustus, 10 populations of P. pachyphyllus, and 10 populations of P. rostriflorus. We applied traditional population genetics approaches as well as spatial and landscape genetics approaches to infer genetic structure and discontinuities among populations.
All three species had significant genetic structure and exhibited isolation by distance, ranging from high structure and low inferred gene flow in the bee-pollinated species P. deustus (F(ST) = 0.1330, R(ST) = 0.4076, seven genetic clusters identified) and P. pachyphyllus (F(ST) = 0.1896, R(ST) = 0.2531, four genetic clusters identified) to much lower structure and higher inferred gene flow in the hummingbird-pollinated P. rostriflorus (F(ST) = 0.0638, R(ST) = 0.1116, three genetic clusters identified).
These three Penstemon species have significant yet strikingly different patterns of population genetic structure, findings consistent with different interactions between landscape features and the dispersal capabilities of their pollinators.
尽管景观遗传学领域发展迅速，但我们对于景观特征如何与生活史特征相互作用影响植物物种的种群遗传结构的理解仍然有限。在这里，我们研究了分布于美国西部大盆地地区的三种风铃草（车前科），它们具有相似的分布范围，但传粉方式不同（蜜蜂和蜂鸟）。大盆地的多山景观为比较不同物种隔离种群中景观和扩散能力的相互作用提供了理想的环境。
我们使用 8 个高度多态的微卫星标记，来鉴定 8 个 P. deustus 种群、10 个 P. pachyphyllus 种群和 10 个 P. rostriflorus 种群内及种群间的中性种群遗传结构。我们应用传统的种群遗传学方法以及空间和景观遗传学方法来推断种群间的遗传结构和不连续性。
这三个物种都具有显著的遗传结构，并表现出距离隔离，从蜜蜂传粉的 P. deustus（F(ST) = 0.1330，R(ST) = 0.4076，鉴定出 7 个遗传群集）和 P. pachyphyllus（F(ST) = 0.1896，R(ST) = 0.2531，鉴定出 4 个遗传群集）具有高度结构和低推断基因流，到蜂鸟传粉的 P. rostriflorus（F(ST) = 0.0638，R(ST) = 0.1116，鉴定出 3 个遗传群集）具有较低的结构和较高的推断基因流。
这三个风铃草物种具有显著但明显不同的种群遗传结构模式，这些发现与景观特征与传粉者扩散能力之间的不同相互作用一致。
