Systematics, biogeography and evolution of northern floras

北方植物区系的系统学、生物地理学和进化

• 批准号: RGPIN-2021-03117
• 负责人: LéveilléBourret, Étienne
• 金额: $ 2.77万
• 依托单位: Université de Montréal
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2022
• 资助国家: 加拿大
• 起止时间: 2022-01-01 至 2023-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=765219
• 关键词: Systematics; biogeography; evolution; northern; floras

A central aim of systematics is to identify the processes that shape diversity across space and time. Northern floras offer interesting opportunities to do so, as they have been through some of the most intense periods of past climate change. My long term research goal is to discover, classify and protect the awe-inspiring biodiversity of northern plants, and to identify the processes responsible for generating and maintaining this diversity. Towards this goal, I will focus on three short-term objectives that will shed light on the impact of past climate change on evolution of northern floras at three evolutionary scales: macro-evolutionary (Objective 1), micro-evolutionary (Objective 2), and ecological (Objective 3). Objective 1 is to quantify the influence of historical climate change on the diversity and evolution of one of the most abundant plant families in the fossil record, Cyperaceae (>1000 fossils). We will first compile a comprehensive database of all fossils reported in the literature, and re-assess their taxonomic affinities through geometric morphometric analysis (BSc 1). The resulting fossil dataset will be of unprecedented size and quality in angiosperms, enabling high-resolution analysis of plant diversification dynamics, biogeography, niche evolution and fruit evolution throughout the last 100 million years that span the evolutionary history of Cyperaceae (MSc 1). Objective 2 is to develop the first genomic resources for Cyperaceae, and to use them to determine how climate influences the frequency of hybridization and introgression. Two Carex genomes will be assembled to chromosome-scale (PhD 1) at low cost from an experimental hybrid, which will allow estimation of the timing and intensity of ancient introgression events, based on the lengths of introgressed genomic blocks. We will also expand on our previous investigations of host-parasite interactions in Cyperaceae by utilizing Anthracoidea fungi, which preferentially parasitize hybrids, as a proxy to infer the frequency of hybridization in deep time (Msc 2). Objective 3 will be to accelerate taxonomic research on the Freshwater Tidal Flora, a rich but threatened North American centre of endemism. Through parallel taxonomic and population genomic studies of two Cyperaceae (BSc 2, MSc 3) and one Asteraceae (PhD 2) lineage endemic to this Flora, we will discover shared patterns of genetic diversity that can be used to prioritize conservation on the most distinct populations and areas. We will then assemble a complete distribution database of all taxa occurring in the Freshwater Tidal Flora (c. 100 species; BSc 3) to test how area, climatic conditions and distance between estuaries affect endemicity, richness, phylogenetic diversity, and population genetic diversity (PhD 2). This combined approach will allow us to discover large-scale historical and ecological processes that shape diversity at all levels of biological complexity, from genes to species and whole communities.

系统学的一个核心目的是确定在时间和时间之间塑造多样性的过程。北部植物群提供了有趣的机会，因为它们经历了过去的气候变化最激烈的时期。我的长期研究目标是发现，分类和保护北部植物的令人敬畏的生物多样性，并确定负责产生和维持这种多样性的过程。为了实现这一目标，我将重点关注三个短期目标，这些目标将揭示过去气候变化对北部植物群在三个进化量表进化的影响：宏观进化（目标1），微观进化（目标2）和生态学（目标3）。 目的1是量化历史气候变化对化石记录中最丰富的植物科之一的多样性和演变的影响，即Cyperaceae（> 1000种化石）。我们将首先编译文献中报道的所有化石的综合数据库，并通过几何形态分析（BSC 1）重新评估其分类学亲和力。所得的化石数据集将在被子植物中具有前所未有的尺寸和质量，从而可以在过去的1亿年中对植物多样化动态，生物地理学，利基进化和水果进化进行高分辨率分析，涵盖了Cyperaceae的进化史（MSC 1）。目标2是开发首个蛋黄科的基因组资源，并使用它们来确定气候如何影响杂交和渗入的频率。通过实验性混合动力，将以低成本将两个Carex基因组组装到染色体规模（PhD 1），这将允许根据侵入性基因组块的长度估算古代渗入事件的时间和强度。我们还将通过利用拟南芥的真菌（优先将杂种杂种，作为推断在深时代的杂交频率（MSC 2）来推断杂交频率的代理（MSC 2），我们还将扩展我们先前对Cyperaceae中宿主 - 寄生虫相互作用的研究（MSC 2）。目标3将是加快对淡水潮汐植物群的分类研究，这是一个富裕但受到威胁的北美特纳中心。通过两种氰基科（BSC 2，MSC 3）和一个星际科（博士学位2）谱系的平行分类学和人群基因组研究，我们将发现可用于在最独特的种群和地区对保护优先级的共同遗传多样性模式。然后，我们将组装一个完整的分布数据库，该数据库的淡水潮汐菌群中发生的所有分类单元（c。100; BSC 3），以测试面积，气候条件和河口之间的距离如何影响流行性，丰富性，丰富性，系统发育多样性和人群遗传多样性（PHD 2）。这种结合的方法将使我们能够发现大规模的历史和生态过程，这些过程在从基因到物种和整个社区的各个级别的生物学复杂性上塑造了多样性。