Evolution and seed dormancy shape plant genotypic structure through a successional cycle
Evolution and seed dormancy shape plant genotypic structure through a successional cycle
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DOI：
10.1073/pnas.2026212118
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发表时间：
2021-08-20
影响因子：
11.1
通讯作者：
Maron, John L.
中科院分区：
文献类型：
--
作者：
Agrawal, Anurag A.;Hastings, Amy P.;Maron, John L.
休眠在植物、动物和微生物中反复进化，并被假设为在面对环境变化时促进持久性。然而，以前的实验没有跟踪人口和性状进化跨越一个完整的演替周期，以询问是否早期的自然选择回合后来加强或删除在人口休眠期。此外，目前还不清楚短期措施的健身预测长期的休眠物种的基因型成功。在这里，我们解决这些问题，使用实验场种群的植物月见草，它演变了五代以上的地块暴露于或保护昆虫植食性。当种群在地面上生存时，防御和生活史特征迅速进化，但种群失去了遗传多样性，并随着继承的进行而崩溃。在>5年的种子休眠后，我们触发了种子库的萌发，并对> 3，000个定殖子进行了基因分型。复活的种群表现出恢复的遗传多样性，减少了早期对选择的反应，并将种群表型推向十年前的起始条件。尽管如此，四个防御和生活史特征仍然与控制组相比，昆虫抑制种群的差异。这些发现捕捉到了生态周期中进化过程中缺失的关键元素，并展示了休眠对未来进化对环境变化的反应的影响。
Dormancy has repeatedly evolved in plants, animals, and microbes and is hypothesized to facilitate persistence in the face of environmental change. Yet previous experiments have not tracked demography and trait evolution spanning a full successional cycle to ask whether early bouts of natural selection are later reinforced or erased during periods of population dormancy. In addition, it is unclear how well short-term measures of fitness predict long-term genotypic success for species with dormancy. Here, we address these issues using experimental field populations of the plant Oenothera biennis, which evolved over five generations in plots exposed to or protected from insect herbivory. While populations existed above ground, there was rapid evolution of defensive and life-history traits, but populations lost genetic diversity and crashed as succession proceeded. After >5 y of seed dormancy, we triggered germination from the seedbank and genotyped >3,000 colonizers. Resurrected populations showed restored genetic diversity that reduced earlier responses to selection and pushed population phenotypes toward the starting conditions of a decade earlier. Nonetheless, four defense and life-history traits remained differentiated in populations with insect suppression compared with controls. These findings capture key missing elements of evolution during ecological cycles and demonstrate the impact of dormancy on future evolutionary responses to environmental change.