No evidence for incipient speciation by selfing in North American Arabidopsis lyrata
No evidence for incipient speciation by selfing in North American Arabidopsis lyrata
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DOI：
10.1111/jeb.13901
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发表时间：
2021-07-14
影响因子：
2.1
通讯作者：
Stift, Marc
中科院分区：
文献类型：
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作者：
Gorman, Courtney E.;Li, Yan;Stift, Marc
自花受精通过减少种群间交配产生的后代的比例来限制基因流动。因此，从异交到自交的交配系统转换可能导致自交和异交谱系之间的生殖隔离，并为物种形成提供起点。在新分化的谱系中，例如在过渡到自交之后，进一步的生殖隔离可以由在授粉之前、期间和之后操作的各种前合子和后合子机制引起。在动物中，合子前屏障往往比合子后屏障进化得更快。对于植物来说，这并不一定是这样，对于植物来说，交配后、受精后和早期作用的合子后障碍的相对重要性研究得少得多。为了测试在育种上不同的北美拟南芥种群之间是否存在授粉后隔离（自交不亲和与自交亲和）和交配系统（异交与自交），我们比较了杂交后的种子设置模式的人口内，人口之间的同一交配系统和人口之间的不同交配系统。我们没有发现任何证据授粉后隔离植物自交群体（自交不亲和，低异交率）和异交群体（自交不亲和，高异交率）通过前合子或早期作用后合子机制。结合其他研究结果表明，在授粉前和授粉过程中没有生殖障碍的作用，我们得出结论，在本研究系统中，向自交的过渡并没有导致自交和异交种群之间的生殖障碍的形成。抒情琴。
Self-fertilization inherently restricts gene flow by reducing the fraction of offspring that can be produced by inter-population matings. Therefore, mating system transitions from outcrossing to selfing could result in reproductive isolation between selfing and outcrossing lineages and provide a starting point for speciation. In newly diverged lineages, for example after a transition to selfing, further reproductive isolation can be caused by a variety of prezygotic and post-zygotic mechanisms that operate before, during and after pollination. In animals, prezygotic barriers tend to evolve faster than post-zygotic ones. This is not necessarily the case for plants, for which the relative importance of post-mating, post-fertilization and early-acting post-zygotic barriers has been investigated far less. To test whether post-pollination isolation exists between populations of North American Arabidopsis lyrata that differ in breeding (self-incompatible versus self-compatible) and mating system (outcrossing versus selfing), we compared patterns of seed set after crosses made within populations, between populations of the same mating system and between populations with different mating systems. We found no evidence for post-pollination isolation between plants from selfing populations (self-compatible, low outcrossing rates) and outcrossing populations (self-incompatible, high outcrossing rates) via either prezygotic or early-acting post-zygotic mechanisms. Together with the results of other studies indicating the absence of reproductive barriers acting before and during pollination, we conclude that the transition to selfing in this study system has not led to the formation of reproductive barriers between selfing and outcrossing populations of North American A. lyrata.