Allopatry, hybridization, and reproductive isolation in Arctostaphylos.
Allopatry, hybridization, and reproductive isolation in Arctostaphylos.
复制标题
Arctostaphylos 的异域、杂交和生殖隔离。
DOI：
10.1002/ajb2.1576
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发表时间：
2020
影响因子：
3
通讯作者：
M. Vasey
中科院分区：
文献类型：
--
作者：
V. T. Parker;C. Y. Rodríguez;Gail Wechsler;M. Vasey
前提
杂交作为进化创新的来源，在渐渗适应、物种形成和适应性辐射中发挥着关键作用。杂交在 Arctostaphylos 中被认为很常见，但在包含多个物种的林中保留了物种边界。 Arctostaphylos 包含二倍体和四倍体，最近的系统发育表明有两个分支；我们假设这些性状的组合会限制或促进杂交率。
方法
我们根据 87 个随机 0.1 公顷地块的进化枝成员和倍性水平统计分析了物种的共现模式。我们对多个位点进行了采样，以根据形态学分析杂交百分比。最后，通过对来自两个进化枝和四倍体的大量类群进行植物标本馆表评分来分析物候期，其次，在两年内调查三个野外地点，以了解共生类群之间物候阶段的差异。
结果
Arctostaphylos 中的大多数类群相对于其他同属物种来说是异域的。当两个类群同时出现时，模式是二倍体与四倍体，或来自不同进化枝的两个二倍体。当三个分类群同时出现时，模式是来自不同进化枝的两个二倍体和一个四倍体。田间和植物标本室数据均表明开花物候在两个进化枝的二倍体之间发生了变化。二倍体进化枝之一和四倍体有相当大的重叠。
结论
Arctostaphylos 的两个深层进化枝在遗传上相距甚远，当类群共存时，杂交很少或不存在。通过共生物种的开花物候学的置换，增强了进化枝之间的生殖隔离。在进化枝内，除了异域分布或不同的倍性水平之外，类群似乎几乎没有生殖障碍。
PREMISE
Hybridization plays a key role in introgressive adaptation, speciation, and adaptive radiation as a source of evolutionary innovation. Hybridization is considered common in Arctostaphylos, yet species boundaries are retained in stands containing multiple species. Arctostaphylos contains diploids and tetraploids, and recent phylogenies indicate two clades; we hypothesize combinations of these traits limit or promote hybridization rates.
METHODS
We statistically analyzed co-occurrence patterns of species by clade membership and ploidy level from 87 random 0.1 ha plots. We sampled multiple sites to analyze for percent hybridization based on morphology. Finally, phenophases were analyzed by scoring herbarium sheets for a large number of taxa from both clades as well as tetraploids, and second, surveying three field sites over two years for divergence in phenological stages between co-occurring taxa.
RESULTS
Most taxa in Arctostaphylos are allopatric relative to other congenerics. When two taxa co-occur, the patterns are a diploid with a tetraploid, or two diploids from different clades. When three taxa co-occur, the pattern is two diploids from different clades and a tetraploid. Field and herbarium data both indicate flowering phenology is displaced between diploids from the two clades; one of the diploid clades and tetraploids overlap considerably.
CONCLUSIONS
The two deep clades in Arctostaphylos are genetically distant, with hybrids rare or non-existent when taxa co-occur. Reproductive isolation between clades is enhanced by displaced flowering phenology for co-occurring species. Within clades, taxa appear to have few reproductive barriers other than an allopatric distribution or different ploidy levels.
影响因子：
3.7
作者：
Abbott, Richard J.
通讯作者：
Abbott, Richard J.
DOI：
10.1002/bies.201500149
发表时间：
2016-02
期刊：
BioEssays : news and reviews in molecular, cellular and developmental biology
影响因子：
--
作者：
Mallet J;Besansky N;Hahn MW
通讯作者：
Hahn MW