Physiology, Phylogeny and Adaptation in Schiedea (Caryophyllaceae): An Endemic Hawaiian Plant Genus

9601325道森这项研究是关于石竹科的功能多样性模式及其系统发育(进化)关系的调查。Schiedea和Alsinidendron属的系统发育(进化树)表明，这两个属起源于同一祖先，并辐射到夏威夷群岛的不同栖息地，包括雨林藤本植物、沿海和亚高山灌木以及草本植物。植物的比较生态学和生理学很少在严格的系统发育背景下进行，了解物种的进化关系。因此，很难知道生理、解剖和形态特征是否是对不同环境的适应，因为这些特征随着进化时间的推移而改变，以响应新生境中的新选择，或者是过去选择的历史产物。这项研究将研究与繁殖系统和形态的变化相关的生理特化模式，这些变化伴随着栖息地偏好的变化。研究目标是：(1)描述9个代表性物种的生理多样性模式(通过测量固碳和失水率、瞬时水分利用效率、碳同位素比率、水力性质及其相关的形态变化)；(2)分析栖息地特征，并将它们与这些物种的功能特征相关联；(3)解释它们的进化关系的功能特征，以了解生理和形态特征的进化模式；(4)详细分析两性物种在物种内和按性别发生的功能变化，这些变化随着两性物种在更干燥的生境和不同繁殖系统的进化而发生。实地研究将提供有关自然条件下功能变异的信息，普通花园研究将提供在没有环境变异的情况下，在受控条件下物种间和性别之间功能变异的信息。特别是，植物水力结构(例如，木材结构和水分传输特性)可能有助于提高Schiedea的抗旱性，因为木质特征的进化和更干燥生境的定居。这项研究是将植物生理生态学与系统发育系统学相结合的首批研究之一，并有助于理解生理和功能性状进化的性质和模式。更多地了解生理和其他功能特征是如何随着环境的变化而随着进化时间的变化而变化的，这对于理解全球气候变化将如何影响本地和农业植物至关重要。

9601325 Dawson This research is an investigation of patterns of functional diversity with respect to their phylogenetic (evolutionary) relationships within Schiedea (Caryophyllaceae). A phylogeny (evolutionary tree) of the genera Schiedea and Alsinidendron shows that the two genera arose from the same ancestor and have radiated into diverse habitats in the Hawaiian Islands, and include rain forest vines, coastal and subalpine shrubs, and herbs. The comparative ecology and physiology of plants has rarely been conducted in a rigorous phylogenetic context, with knowledge of the evolutionary relationships of the species. As a result, it is difficult to know whether physiological, anatomical and morphological traits are adaptations to different environments because these traits have changed through evolutionary time in response to novel selection in new habitats or are historical artifacts of past selection. This research will study patterns of physiological specialization associated with shifts in breeding system and morphology that accompany shifts in habitat preference. Research objectives are: (1) to describe the patterns of physiological diversity (patterns of water use and water-use efficiency using measurements of carbon fixation and water loss rates, instantaneous water use efficiency, carbon isotope ratio, hydraulic properties, and their associated morphological changes) for 9 representative species; (2) analyze habitat characteristics and correlate them with the functional traits for these species; (3) interpret functional characteristics with respect to their evolutionary relationships to understand patterns of physiological and morphological character evolution; and (4) provide a detailed analysis of functional changes within species and by gender that have occurred as hermaphroditic species colonized drier habitats and different breeding systems evolved. Field studies will provide information about functional variation under natural conditions, and common garden studies will pr ovide information about functional variation among species and by gender under controlled conditions in the absence of environmental variation. In particular, plant hydraulic architecture (e.g., wood structure and water transport properties) is likely to have contributed to enhanced drought tolerance for Schiedea with evolution of woody features and colonization of drier habitats. This study is one of the first to merge plant physiological ecology with phylogenetic systematics, and permits an understanding of the nature and patterns of physiological and functional character evolution. Greater knowledge of how physiological and other functional characters change through evolutionary time with changes in environment is critical to understand how global climate changes will affect both native and agricultural plants.