Dimensions US–China: Collaborative Research: Consequences of diversity in Asian and American oak syngameons for functional variation, adaptation and symbiont biodiversity

世界上大约有425种橡树，即使通过杂交与近亲交换基因，也能保持物种身份。这段进化和基因交换的历史塑造了北半球生态系统的生物多样性。橡树具有生态多样性，相关物种通常生长在附近，但专门生长在土壤质地和湿度水平或自然火灾频率不同的森林景观区域。基因交换可以在橡树物种之间移动这种生态特化，扩大它们的范围和应对气候变化的能力。这些基因交换的影响可能会超出橡树本身。在世界范围内，橡树拥有大约1000种瘿蜂和高度多样化的真菌群落，这些真菌与它们的根（如菌根）和叶内（如内生菌）有关。通过成对的实地调查和普通园林实验，pi将评估杂交和渗入对美国和中国栓皮栎物种及其共生体的遗传、系统发育和功能多样性的影响。这项工作还将提供基于探究的K-12、本科和研究生教育；通过橡树物候学社区科学计划向公众提供重要的自然历史培训；以及将研究成果带给公众的出版物。两个跨学科的研究小组，一个在美国，一个在中国，将研究橡树的基因组、功能和系统发育多样性如何影响菌根真菌、内生真菌、瘿蜂和其他与它们相关的昆虫群落。研究将集中在两个相关的杂交物种群：美国的黑栎（Quercus macrocarpa）及其近缘种和中国的宝李（Quercus serrata）及其近缘种。该项目有三个目标，每个目标在中国和美国并行进行。在目标1中，团队将对自然种群进行大范围的系统基因组调查，以重建基因组马赛克，表征叶片功能性状的地理模式，并表征相关菌根真菌、叶片内生真菌和瘿蜂的功能和系统发育多样性。在目标2中，我们将在不同的气候梯度下种植普通园林，以评估遗传变异和种群分化对不同气候条件下橡树功能和光谱性状以及相对适合度的影响，以及这些因素如何影响橡树相关真菌和昆虫群落的系统发育和功能多样性。在目标3中，团队将使用第二组普通花园实验来评估植物群落和系统发育多样性如何影响局焦栎物种的遗传、系统发育和功能多样性。该项目将提供一个综合的视角，了解物种内部和物种之间的橡树多样性如何影响整个北半球以橡树为主的生态系统的广泛多样性。该奖项反映了美国国家科学基金会的法定使命，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 world’s approximately 425 oak species maintain species identity even while exchanging genes with their close relatives through hybridization. This history of evolution and genetic exchange has shaped the biodiversity of northern hemisphere ecosystems. Oaks are ecologically diverse, with related species often growing in close proximity but specializing on areas of the forest landscape that differ in soil texture and moisture level or in the frequency of natural fires. Gene exchange can move such ecological specializations between oak species, broadening their ranges and ability to respond to climate change. The impacts of these genetic exchanges may extend beyond the oaks themselves. Oaks host an estimated 1000 gall wasp species worldwide and highly diverse communities of fungi associated with their roots (as mycorrhizae) and inside their leaves (as endophytes). Using paired field surveys and common garden experiments the PIs will evaluate the effects of hybridization and introgression on the genetic, phylogenetic, and functional diversity of focal oak species and their symbionts in the US and China. This work will also provide inquiry-based K-12, undergraduate, and graduate education; critical natural history training to the public through a community-science initiative in oak phenology; and publications that will bring research to public audiences.Two interdisciplinary teams of researchers, one based in the US and one in China, will investigate how genomic, functional, and phylogenetic diversity of oak trees shape the mycorrhizal fungi, endophytic fungi, and gall wasp and other insect communities that associate with them. Research will focus on two related groups of interbreeding species: bur oak (Quercus macrocarpa) and relatives in the US and bao li (Quercus serrata) and relatives in China. The project has three objectives, each conducted in parallel in China and the U.S. In Objective 1 the teams will perform range-wide phylogenomic surveys of natural populations to reconstruct genomic mosaics, characterize geographic patterns of leaf functional traits, and characterize functional and phylogenetic diversity of associated mycorrhizal fungi, leaf endophytic fungi, and gall wasps. In Objective 2 common gardens will be planted across climatic gradients to evaluate the effects of genetic variation and population differentiation on oak functional and spectral traits and relative fitness in different climates, and how these influence the phylogenetic and functional diversity of oak-associated fungal and insect communities. In Objective 3 the teams will use a second set of common garden experiments to evaluate how plant community and phylogenetic diversity affects focal oak species genetic, phylogenetic, and functional diversity. The project will provide an integrative perspective on how oak diversity within and among species impacts the broad diversity of oak-dominated ecosystems across the northern hemisphere.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.