Adaptation and selection in the Senecio (Asteraceae) hybrid zone on Mount Etna, Sicily
Adaptation and selection in the Senecio (Asteraceae) hybrid zone on Mount Etna, Sicily
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DOI：
10.1111/j.1469-8137.2009.02944.x
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发表时间：
2009-01-01
期刊：
影响因子：
9.4
通讯作者：
Abbott, Richard J.
中科院分区：
文献类型：
--
作者：
Brennan, Adrian C.;Bridle, Jon R.;Abbott, Richard J.
P>；混合区理论为基因流动和选择的测量和测试提供了一个强大的理论框架。对位于西西里岛埃特纳山的千里光和千里光菊花杂交区进行了调查，以鉴定发散选择下的表型性状，并评估了针对杂交种的内在和外部选择对杂交区维持的贡献。对来自埃特纳山14个地点的千里光样本进行了24个数量性状的分析，分为4个组(QTGs)、6个等位酶和7个简单序列重复(SSR)基因座，以描述整个杂交区的变异模式。观察到3个QTGs相对于分子克隆的倾角宽度变窄或倾角中心位置移动，表明这些性状可能受到外部环境选择的影响。海拔高度是描述物种分布的关键，但对杂交种的扩散和内在选择在较小的空间尺度上解释了格局。新植物学家(2009年)183：702-717doi：10.1111/j.1469-8137.2009.02944.x新植物学家(2009年)183：702-717doi：10.1111/j.1469-8137.2009.02944.x
P>Hybrid zone theory provides a powerful theoretical framework for measuring and testing gene flow and selection. The Senecio aethnensis and Senecio chrysanthemifolius hybrid zone on Mount Etna, Sicily, was investigated to identify phenotypic traits under divergent selection and to assess the contributions of intrinsic and extrinsic selection against hybrids to hybrid zone maintenance.Senecio samples from 14 sites across Mount Etna were analyzed for 24 quantitative traits classified into four groups (QTGs), six allozymes and seven simple sequence repeat (SSR) loci to describe patterns of variation throughout the hybrid zone.Narrower cline widths or shifts in cline centre position were observed for three QTGs relative to the molecular clines, indicating that these traits are likely to be under extrinsic environmental selection. Altitude was key to describing species distributions, but dispersal and intrinsic selection against hybrids explained patterns at smaller spatial scales. The hybrid zone was characterized by strong selection against hybrids, high dispersal rates, recent species contact and few loci differentiating QTGs based on indirect measures.These results support the hypothesis that extrinsic and intrinsic selection against hybrids maintains the hybrid zone and species distinctiveness despite gene flow between the two Senecio species on Mount Etna.New Phytologist (2009) 183: 702-717doi: 10.1111/j.1469-8137.2009.02944.x.