ECOLOGICAL BARRIERS TO GENE FLOW BETWEEN RIPARIAN AND FOREST SPECIES OF AINSLIAEA (ASTERACEAE)
ECOLOGICAL BARRIERS TO GENE FLOW BETWEEN RIPARIAN AND FOREST SPECIES OF AINSLIAEA (ASTERACEAE)
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DOI：
10.1111/j.1558-5646.2010.01129.x
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发表时间：
2011-02
期刊：
影响因子：
3.3
通讯作者：
Y. Mitsui;Naofumi Nomura;Y. Isagi;H. Tobe;H. Setoguchi
中科院分区：
文献类型：
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作者：
Y. Mitsui;Naofumi Nomura;Y. Isagi;H. Tobe;H. Setoguchi
了解栖息地相关适应在减少基因流动中的作用，从而导致种群分化和物种形成，是进化生物学中的一个主要问题。我们证明了生境分化在两种自然杂交的河岸和非河岸植物，Ainsliaea faurieana和A。apiculata（菊科），产于日本屋久岛。通过分析六个同域地点的细尺度种群结构，我们发现，在河岸-森林过渡中，叶片形状、地理、光照条件和基因型的变化具有很强的相关性。没有证据表明，有效的基因流之间的两个物种在大多数的过渡区，虽然NewHybrid聚类分析证实种间杂交。然而，一个相对较高水平的基因流，观察到一个区域，一个更分散的生态交错区和中间的洪水和光照条件，可能产生的人为干扰。这些结果表明，河岸和森林物种之间的基因流动的障碍主要是生态。其他常见的花园实验表明，这两个物种的适应性分化对比洪水和光照环境。总体而言，我们的研究表明，适应不同的栖息地可能会导致生殖隔离障碍的形成和维持不同的物种边界。
Understanding the role of habitat‐associated adaptation in reducing gene flow resulting in population differentiation and speciation is a major issue in evolutionary biology. We demonstrate a significant role for habitat divergence in species isolation between two naturally hybridizing riparian and nonriparian plants, Ainsliaea faurieana and A. apiculata (Asteraceae), on Yakushima Island, Japan. By analyzing the fine‐scale population structure at six sympatric sites, we found that variations in leaf shape, geography, light conditions, and genotype were strongly correlated across riverbank–forest transitions. No evidence of effective gene flow was found between the two species across the majority of the transition zones, although the NewHybrid clustering analysis confirmed interspecific hybridization. However, a relatively high level of gene flow was observed across one zone with a more diffuse ecotone and intermediate flooding and light conditions, possibly generated by human disturbances. These results suggest that the barriers to gene flow between the riparian and forest species are primarily ecological. Additional common garden experiments indicated that the two species are adaptively differentiated to contrasting flooding and light environments. Overall, our study suggests that adaptations to different habitats can lead to the formation of reproductive isolating barriers and the maintenance of distinct species boundaries.