Integration and modularity in grass diversification

高草草原是美国的一个标志性景观，由一组被称为Andropogoneae的草主导，这是世界范围内大部分植物生产力的原因。这一群体也是中非和巴西广阔热带草原的特征，包含许多经济上重要的作物物种，如玉米和高粱。然而，这个群体是如何主宰这些栖息地并多样化成大约1200种物种的，目前还不清楚。该类群中的物种具有一系列的花结构，这表明该类群的进化和多样化可能受到其生殖结构功能的影响。该项目将测试这一假设，使用比较形态和功能分析这些生殖结构的背景下的仙女座植物的生殖系统。该研究计划包括一系列培训机会，为早期职业研究人员，包括代表性不足的群体的成员，以及传播结果的方法。这项研究的结果将揭示形态发育和自然选择如何在这个草类部落的进化历史中相互作用，并将为农学家提供提高粮食作物生产力的新见解。 研究人员将使用三个综合目标来评估这些变化的系统发育，形态和功能后果，以测试生殖结构的整合和模块化的变化是否与Andropogoneae的多样化相关。他们将利用现有的大量核基因组序列数据，绘制出几乎完整的仙女座菌科物种水平系统发育史。将使用半自动化工具捕获来自所有物种的小穗和小穗对的形态测量数据，并将对其进行分析以评估小穗和小穗对结构之间的协方差（整合）以及它们之间的形态测量距离（差异和模块性）。整合，差异，模块化，然后将映射到的遗传，将潜在的形态特征，与多样化的模式。实验将测试小穗和小穗对授粉和种子传播的性能，以量化整合和模块化的功能后果。在这样做的过程中，研究人员将用新的元数据来增加植物标本馆的收藏，并为基因组数据库做出贡献，这将促进未来对草系统生物学和植物育种的研究。该研究的贡献将在一组植物的形态和功能多样性的基因组水平上创建一个综合的进化观点，这些植物是草原生态和美国农业的核心。该奖项反映了NSF的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

The tallgrass prairie is an iconic American landscape dominated by a single group of grasses known as the Andropogoneae, which is responsible for much of the plant productivity world-wide. This group also characterizes the vast tropical grasslands of central Africa and Brazil and contains many economically important crop species, such as corn and sorghum. However, how this group came to dominate these habitats and diversify into approximately 1200 species is unknown. Species within the group have a range of floral architectures, which suggests that the evolution and diversification of this group may be influenced by the function of its reproductive structures. This project will test this hypothesis using comparative morphological and functional analyses of these reproductive structures in the context of the phylogeny of the Andropogoneae. The research plan incorporates a range of training opportunities for early-career researchers, including members of underrepresented groups, and methods for disseminating the results. Outcomes of the research will reveal how morphological development and natural selection have interacted over evolutionary history for this tribe of grasses and will provide agronomists with new insights for improving the productivity of its grain crops. Researchers will test whether shifts in the integration and modularity of reproductive structures correlate with diversification in the Andropogoneae using three integrated aims that assess the phylogenetic, morphological, and functional consequences of these changes. They will produce a near-complete species-level phylogeny of Andropogoneae by leveraging extensive nuclear genome sequence data already in hand. Morphometric data for spikelets and spikelet pairs from all species will be captured using semi-automated tools and will be analyzed to assess the covariance between spikelet and spikelet pair structures (integration) and the morphometric distances between them (disparity and modularity). Integration, disparity, and modularity will then be mapped on the phylogeny, as will the underlying morphological characters, to be correlated with patterns of diversification. Experiments will test the performance of the spikelets and spikelet pairs for pollination and seed dispersal to quantify the functional consequences of integration and modularity. In doing so, researchers will augment herbarium collections with new metadata and contribute to genomic data repositories that will facilitate future research on grass systematic biology and plant breeding. The contributions of the research will create an integrated evolutionary view at the genomic level of morphological and functional diversification in a group of plants that are central to grassland ecology and US agriculture.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.