Dimensions US-China: Collaborative Research: Allozomes and dioecy in plants as drivers of multi-level biodiversity

虽然大多数开花植物(被子植物)的花结合了雄花和雌花器官，但估计有7%的开花植物是雌雄异株的，这意味着雄花和雌花在不同的植物上。所有的杨树和柳树都是雌雄异株的，这两个属是美国许多地区最丰富的乔灌木和中国。这项研究旨在了解杨树和柳树单性花进化的遗传基础，雄性和雌性个体之间防御和挥发性化学物质的差异，以及这些植物中不同的化学成分如何影响昆虫的生物多样性。此外，杨树和柳树也是木材和生物燃料行业的重要组成部分，因此这项研究的结果可能会为如何提高这两个属的生长和产量提供新的见解。美国和中国研究人员的合作将为超过15名研究生和5名博士后学者提供广泛的跨学科和跨文化培训机会，研究产生的数据将被纳入中美两国机构将要教授的课程的教材中。数十名来自不同背景的本科生将通过直接参与数据收集和分析，或通过获取数据进行研究沉浸体验，接受植物基因组学和功能生态学方面的培训。最后，研究人员将领导针对德克萨斯州农村地区未被充分代表的群体的K-12教师培训研讨会，以鼓励教授生物多样性的基础理论。这项研究将通过对杨树和柳树中用于防御和挥发性化学的性别二态的全面调查来研究功能性生物多样性，并确定性别二态如何影响传粉者的吸引、草食动物的取食偏好和整体节肢动物群落结构。生物多样性的遗传方面将通过与常染色体相比较的同种异体的群体基因组特征来研究。研究人员将绘制一套16种柳属和杨属植物的性别决定区域(SDR)的染色体位置图，确定这些基因组区域是否包含与它们对SDR移动的理论影响一致的防御和挥发性化学基因座，并调查预测的种群基因组模式，这些差异是由于性拮抗基因座与SDR之间的相互作用造成的。这项研究的系统发育部分将通过发展和整合杨属、柳属和密切相关属的系统发育来理解SDR在该科的进化过程中移动了多少次，SDR在大小和组成上如何变化，以及SDR的移动是否与种间杂交的障碍相关，将性别二态和异体进化置于历史的背景下。

Although most flowering plants (angiosperms) have flowers that combine male and female organs, an estimated seven percent of flowering plant species are dioecious, meaning male and female flowers are on separate plants. All poplars and willows are dioecious and these two genera are the most abundant trees and shrubs in many parts of the United States and China. This research aims to understand the genetic basis for the evolution of unisexual flowers in poplars and willows, how defense and volatile chemical compounds differ between male and female individuals, and how different chemical profiles within these plants affects insect biodiversity. Moreover, poplars and willows are also important components of the timber and biofuels industries, so results from this research may lead to new insights into how growth and yield may be improved in the two genera. The collaboration between United States and Chinese researchers will provide extensive cross-disciplinary and cross-cultural training opportunities for over fifteen graduate students and five postdoctoral scholars, and the data generated from the research will be incorporated into teaching materials for courses to be taught in both Chinese and US institutions. Dozens of undergraduates from diverse backgrounds will be trained in plant genomics and functional ecology through direct contributions to data collection and analysis, or through access to the data for research immersion experiences. Finally, researchers will lead K-12 teacher training workshops targeted at under-represented groups in rural Texas to encourage teaching of the foundational theories of biodiversity.This research will address functional biodiversity with a comprehensive survey of gender dimorphism for defense and volatile chemistry in Populus and Salix, and determine how gender dimorphism influences pollinator attraction, herbivore feeding preferences, and overall arthropod community structure. Genetic aspects of biodiversity will be investigated by population genomic characterization of the allosomes in comparison to autosomes. Researchers will map the chromosomal locations of sex determination regions (SDRs) in a suite of sixteen Salix and Populus species, determine whether these genomic regions contain defense and volatile chemistry loci consistent with their theoretical influence on movement of the SDR, and investigate predicted population genomic patterns of allosome divergence caused by interactions between sexually antagonistic loci with the SDR. The phylogenetic component of this research will place gender dimorphism and allosome evolution in a historical context by developing and integrating robust phylogenies of Populus, Salix, and closely related genera within the Salicaceae in order to understand how many times the SDR has moved during evolution of the family, how the SDR has changed in size and composition, and whether movement of the SDR correlates with barriers to interspecific hybridization.