RUI: Collaborative Research: Trait differentiation and local adaptation to depth within meadows of the foundation seagrass Zostera marina

RUI：合作研究：大叶草码头基础草甸内的性状分化和局部适应深度

• 批准号: 1851432
• 负责人: Cynthia Hays
• 金额: $ 21.71万
• 依托单位: Keene State College
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-04-01 至 2024-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1851432&HistoricalAwards=false
• 关键词: RUI; Collaborative; Research; Trait; differentiation

Understanding how species cope with spatial variation in their environment (e.g. gradients in light and temperature) is necessary for informed management as well as for predicting how they may respond to change. This project will examine how key traits vary with depth in common eelgrass (Zostera marina), one of the most important foundation species in temperate nearshore ecosystems worldwide. The investigators will use a combination of experiments in the field and lab, paired with fine-scale molecular analyses, to determine the genetic and environmental components of seagrass trait variation. This work will provide important information on the microevolutionary mechanisms that allow a foundation species to persist in a variable environment, and thus to drive the ecological function of whole nearshore communities. The Northeastern University graduate and Keene State College (KSC) undergraduate students supported by this project will receive training in state-of-the-art molecular techniques, as well as mentorship and experience in scientific communication and outreach. A significant portion of KSC students are from groups under-represented in science. Key findings of the research will be incorporated into undergraduate courses and outreach programs for high school students from under-represented groups, and presented at local and national meetings of scientists and stakeholders. Local adaptation, the superior performance of "home" versus "foreign" genotypes in a local environment, is a powerful demonstration of how natural selection can overcome gene flow and drift to shape phenotypes to match their environment. The classic test for local adaptation is a reciprocal transplant. However, such experiments often fail to capture critical aspects of the immigration process that may mediate realized gene flow in natural systems. For example, reciprocal transplant experiments typically test local and non-local phenotypes at the same (often adult) life history stage, and at the same abundance or density, which does not mirror how dispersal actually occurs for most species. In real populations, migrants (non-local) often arrive at low numbers compared to residents (local), and relative frequency itself can impact fitness. In particular, rare phenotypes may experience reduced competition for resources, or relative release from specialized pathogens. Such negative frequency dependent selection can reduce fitness differences between migrants and residents due to local adaptation, and magnify effective gene flow, thus maintaining greater within-population genetic diversity. The investigators will combine spatially paired sampling and fine-scale molecular analyses to link seed/seedling trait variation across the depth gradient at six meadows to key factors that may drive these patterns: local environmental conditions, population demography, and gene flow across depths. The team will then experimentally test the outcome of cross-gradient dispersal in an ecologically relevant context, by reciprocally out-planting seeds from different depths and manipulating relative frequency in relation to both adults and other seedling lineages. The possible interaction between local adaptation and frequency-dependence is particularly relevant for Zostera marina, which represents one of the best documented examples of the ecological effects of genetic diversity and identity. Further, a better understanding of seagrass trait differentiation is not simply a matter of academic interest, but critical to successful seagrass restoration and conservation.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

了解物种如何应对其环境中的空间变化（例如，光和温度的梯度）对于知情管理是必要的，以及预测它们如何响应变化。该项目将研究关键特征如何随着普通鳗鱼（Zostera Marina）的深度而变化，这是全球温带近岸生态系统中最重要的基础物种之一。研究人员将在田间和实验室中使用实验的组合，并与精细的分子分析相结合，以确定海草性状变化的遗传和环境成分。这项工作将提供有关微观进化机制的重要信息，这些机制使地基物种可以在可变环境中持续存在，从而推动整个近岸社区的生态功能。该项目支持的东北大学毕业生和基恩州立学院（KSC）的本科生将接受最先进的分子技术培训，以及科学交流和外展方面的指导和经验。 KSC学生中很大一部分来自科学领域不足的小组。该研究的主要发现将纳入来自代表性不足的团体的高中生的本科课程和外展计划，并在科学家和利益相关者的当地和国家会议上介绍。本地环境中“家庭”与“外国”基因型的优越性能是局部适应性的强大证明，表明自然选择如何克服基因流和漂移以形成表型以匹配其环境。局部适应的经典测试是互惠移植。但是，这种实验通常无法捕获移民过程的关键方面，这些方面可能介导自然系统中实现的基因流。例如，相互移植实验通常在相同（通常是成人）生活史阶段，以及在相同的丰度或密度下测试局部和非本地表型，这并不能反映大多数物种实际发生的分散性。在实际人群中，与居民（本地）相比，移民（非本地）通常得分很少，并且相对频率本身可能会影响适应性。特别是，罕见的表型可能会减少对资源的竞争或专门病原体的相对释放。这种负频率依赖性选择可以减少由于局部适应而导致的移民和居民之间的适应性差异，并放大了有效的基因流，从而保持了较大的人口内遗传多样性。研究人员将结合空间配对的采样和细度分子分析，以将跨六个草地的深度梯度上的种子/幼苗性状变化与可能推动这些模式的关键因素联系起来：局部环境条件，种群人口统计学和基因流跨深度。然后，该团队将通过在生态相关的环境中实验测试跨梯度分散的结果，通过相对于不同深度的种子相互植入的种子，并操纵相对于成年人和其他幼苗谱系的相对频率。局部适应性和频率依赖性之间的可能相互作用与Zostera Marina特别相关，Zostera Marina代表了遗传多样性和身份的生态效应的最佳示例之一。此外，对海草性状差异化的更好理解不仅是学术兴趣问题，而且对于成功的海草恢复和保护至关重要。该奖项反映了NSF的法定任务，并且被认为是值得通过基金会的知识分子和更广泛影响的评估评估来支持的。

项目成果

Local Adaptation in Marine Foundation Species at Microgeographic Scales

• DOI: 10.1086/714821
• 发表时间: 2021-08-01
• 期刊: BIOLOGICAL BULLETIN
• 影响因子: 1.6
• 作者: Hays, C. G.;Hanley, T. C.;Sotka, E. E.
• 通讯作者: Sotka, E. E.

Intra-Meadow Variation in Seagrass Flowering Phenology Across Depths

不同深度海草开花物候的草甸内变化

• DOI: 10.1007/s12237-020-00814-0
• 发表时间: 2021
• 期刊: Estuaries and Coasts
• 影响因子: 2.7
• 作者: von Staats, Daniel A.;Hanley, Torrance C.;Hays, Cynthia G.;Madden, Sophia R.;Sotka, Erik E.;Hughes, A. Randall
• 通讯作者: Hughes, A. Randall