A hybrid zone dominated by fertile F1s of two alpine shrub species, Phyllodoce caerulea and Phyllodoce aleutica, along a snowmelt gradient
A hybrid zone dominated by fertile F1s of two alpine shrub species, Phyllodoce caerulea and Phyllodoce aleutica, along a snowmelt gradient
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DOI：
10.1111/j.1420-9101.2007.01476.x
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发表时间：
2008-03
影响因子：
2.1
通讯作者：
Y. Kameyama;T. Kasagi;G. Kudo
中科院分区：
文献类型：
--
作者：
Y. Kameyama;T. Kasagi;G. Kudo
在高山生态系统中，由融雪时间差异产生的陡峭环境梯度为高山植物创造了动态选择机制。由于这些梯度直接改变了开花物候，它们可以影响花粉介导的基因在单一物种和近缘物种群体之间的流动。在日本北部，沿融雪梯度，我们发现两种高山灌木种毛竹（Phyllodoce caerulea）和阿留留卡（P. aleutica）的可育f15占主导地位的杂交带。种子萌发证实了F1杂种的育性，使回交和F2植株的罕见和缺失令人费解。F1杂交的长期无性繁殖（至少几千年前）有助于维持这一独特的杂交区。叶绿体DNA单倍型的分布模式表明，F1的形成可能是由亲本种之间沿融雪梯度的定向花粉流动引起的。在此基础上，讨论了这一独特杂交带的生态和进化意义。
In alpine ecosystems, the steep environmental gradients produced by the difference in snowmelt timing create a dynamic selective regime for alpine plants. As these gradients directly alter flowering phenology, they can affect pollen‐mediated gene flow among populations of single and related species. In northern Japan, we found a hybrid zone dominated by fertile F1s of two alpine shrub species, Phyllodoce caerulea and P. aleutica, along a snowmelt gradient. Seed germination confirmed the fertility of F1 hybrid, making the rarity and absence of backcross and F2 plants puzzling. The long‐term clonal perpetuation of F1 hybrids (at least a few thousand years ago) contributes the maintenance of this unique hybrid zone. The distribution patterns of chloroplast DNA haplotypes suggest that F1 formation might be caused by directional pollen flow between parental species along the snowmelt gradient. Based on these results, we discuss the ecological and evolutionary significance of this unique hybrid zone.