Differences in flowering time maintain species boundaries in a continental radiation of Viburnum.
Differences in flowering time maintain species boundaries in a continental radiation of Viburnum.
复制标题
开花时间的差异维持了荚莲属植物大陆辐射中的物种边界。
DOI：
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发表时间：
2019
期刊：
影响因子：
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通讯作者：
M. Donoghue
中科院分区：
文献类型：
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作者：
E. Spriggs;Caroline Schlutius;Deren A. R. Eaton;Brian Park;Patrick W. Sweeney;E. Edwards;M. Donoghue
前提
我们采用综合方法来评估基因渗入和更新世气候波动如何塑造荚莲属植物的核心Lentago进化枝的多样化，这是一组具有广泛同源性的五种互育物种。我们专门测试了开花时间是否在维持物种隔离方面发挥作用。
方法
使用 103 个个体的 RAD-seq 数据来推断物种关系和每个物种内的遗传结构。根据植物标本馆标本记录的历史开花日期比较物种之间的开花时间。
结果
在每个物种中，我们发现开花日期和纬度之间存在密切关系，例如南方种群比北方种群开花早。在同源地区，物种按顺序开花而不是同时开花，所有物种对的开花日期偏移≥9天。在两个案例中，开花时间的偏移似乎是适应不同气候的偶然结果，但在最近分化的姐妹种 V. prunifolium 和 V. rufidulum 中，我们发现证据表明强化导致了生殖特征的位移。长期趋势表明，为了应对最近的气候变化，最北端的两个物种开花时间提前。
结论
我们认为，Lentago 分支中的物种形成主要是通过异域种群的生态分化而发生的，但开花时间的差异对于维持初始物种在二次接触时的分离至关重要。这些因素的结合可能是许多其他植物进化枝多样化的基础。
PREMISE
We take an integrative approach in assessing how introgression and Pleistocene climate fluctuations have shaped the diversification of the core Lentago clade of Viburnum, a group of five interfertile species with broad areas of sympatry. We specifically tested whether flowering time plays a role in maintaining species isolation.
METHODS
RAD-seq data for 103 individuals were used to infer the species relationships and the genetic structure within each species. Flowering times were compared among species on the basis of historical flowering dates documented by herbarium specimens.
RESULTS
Within each species, we found a strong relationship between flowering date and latitude, such that southern populations flower earlier than northern ones. In areas of sympatry, the species flower in sequence rather than simultaneously, with flowering dates offset by ≥9 d for all species pairs. In two cases it appears that the offset in flowering times is an incidental consequence of adaptation to differing climates, but in the recently diverged sister species V. prunifolium and V. rufidulum, we find evidence that reinforcement led to reproductive character displacement. Long-term trends suggest that the two northern-most species are flowering earlier in response to recent climate change.
CONCLUSIONS
We argue that speciation in the Lentago clade has primarily occurred through ecological divergence of allopatric populations, but differences in flowering time were essential to maintain separation of incipient species when they came into secondary contact. This combination of factors may underlie diversification in many other plant clades.
影响因子：
3.3
作者：
J. K. Pritchard;Matthew Stephens;Peter Donnelly
通讯作者：
J. K. Pritchard;Matthew Stephens;Peter Donnelly
影响因子：
11.6
作者：
Prevey, Janet;Vellend, Mark;Rixen, Christian
通讯作者：
Rixen, Christian
影响因子：
10.7
作者：
Durand, Eric Y.;Patterson, Nick;Slatkin, Montgomery
通讯作者：
Slatkin, Montgomery