Collaborative Research: Replicated evolution of leaf form in a neo-tropical radiation of Viburnum (Adoxaceae)

合作研究：新热带辐射中荚莲属植物（Adoxaceae）叶形的复制进化

• 批准号: 1753504
• 负责人: Erika Edwards
• 金额: $ 34.77万
• 依托单位: Yale University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2017
• 资助国家: 美国
• 起止时间: 2017-07-01 至 2021-04-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1753504&HistoricalAwards=false
• 关键词: Collaborative; Research; Replicated; evolution; leaf

Much remains unknown about the genesis of biological diversity, including the origin of new species, yet such knowledge is critical to understand evolution and to make predictions about responses to rapid environmental change. This research will investigate a striking case in a group of trees and shrubs (Viburnum) in which rapid differentiation appears to have occurred repeatedly into two radically different plant forms. Major differences in the leaves of these plants appear to have resulted from adaptation to adjacent forest types that differ subtly in environmental variables. The evident replication of this process in several different mountain regions throughout the New World tropics, provides a rare opportunity to critically test a model of rapid ecological speciation. Detailed studies of adjacent plant populations will be carried out in different mountain regions in Mexico with the aim of identifying the environmental factors and the nature of the variation within populations that have favored the rapid evolution of these leaf traits. It should also be possible to identify genes that underlie these key plant characteristics by taking advantage of natural hybridization between these species. These studies will yield general insights into speciation but also into the adaptive significance of the leaf traits that differentiate related species throughout the flowering plants. This research will be carried out in collaboration with Mexican scientists and will involve multiple undergraduate and graduate students. Outreach activities have been designed to foster interactions between participants from the United States and Mexico. This project focuses specifically on understanding the drivers of speciation in three species pairs in the mountains of Eastern and Southern Mexico. The two species in each pair differ dramatically in leaf size and shape (large and round versus small and elliptical), in leaf margins (toothed versus smooth), and in leaf pubescence (densely hairy versus lacking hairs). The research will focus on quantifying variation within individual plants, within populations, and between the species pairs, and on determining the abiotic and biotic factors that differ between their forest habitats. Hypotheses on the adaptive value of the leaf variables will be tested using transects between adjacent habitats and a reciprocal transplant experiment. In areas that have long been disturbed by indigenous agricultural practices, extensive hybridization has resulted in a wide array of intermediate leaf forms. Molecular analyses of these hybrid swarms should allow the identification of the major genes that underlie differences in leaf form. This project is jointly funded with the Office of International Science and Engineering.

关于生物学多样性的起源，包括新物种的起源，这些知识对于了解进化并预测对快速环境变化的反应至关重要。这项研究将调查一组树木和灌木（Viburnum）中的惊人病例，其中快速分化似乎反复地发生在两种截然不同的植物形式中。这些植物的叶子的主要差异似乎是由于对邻近森林类型的适应而导致的，这些森林类型在环境变量中略有不同。在整个新世界热带地区的几个不同山区中，这一过程的明显复制提供了罕见的机会，可以批判性地测试快速生态物种形成模型。对邻近植物种群的详细研究将在墨西哥的不同山区进行，目的是确定人们有利于这些叶片特征快速演变的人群中的环境因素和性质。还应该可以通过利用这些物种之间的自然杂交来确定这些关键植物特征的基因。这些研究将产生对物种形成的一般见解，也将对叶片性状的适应性意义，这些叶子特征在整个开花植物中区分相关物种。这项研究将与墨西哥科学家合作进行，并将涉及多个本科生和研究生。外展活动旨在促进美国和墨西哥参与者之间的互动。 该项目专门针对在墨西哥山区和南部的三种物种对中理解物种驱动因素。每对中的两个物种在叶片和形状（大小和椭圆形）上，叶边缘（齿和光滑）以及叶柔毛（叶柔毛）（毛毛毛和缺乏毛发）在叶片边缘（齿和光滑）中差异很大。这项研究将集中于量化单个植物，种群内以及物种对之间的变化，并确定其森林栖息地之间不同的非生物和生物因素。关于叶片变量自适应值的假设将使用相邻栖息地和相互移植实验之间的横断面进行测试。 在长期以来一直受到土著农业实践打扰的地区，广泛的杂交导致了广泛的中间叶片形式。 这些杂交群的分子分析应允许鉴定叶片形式差异的主要基因。该项目由国际科学与工程办公室共同资助。