ROW/RPG: Developmental Plasticity in Polygonum viviparum

ROW/RPG：珠芽蓼的发育可塑性

• 批准号: 9109777
• 负责人: Pamela Diggle
• 金额: $ 2.3万
• 依托单位: University of Colorado at Boulder
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 1991
• 资助国家: 美国
• 起止时间: 1991-07-15 至 1993-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9109777&HistoricalAwards=false
• 关键词: ROW; RPG; Developmental; Plasticity; Polygonum

The underlying assumption of many evolutionary studies is that evolutionary change in developmental processes occurs indirectly, by selection on the characters formed by those processes. While variation among characters must be the result of variation in underlying developmental processes, it is the functioning of those characters that is subject to natural selection. Evolutionary change in development results, but only because these processes give rise to the selected character. In contrast, a little explored aspect of evolution is the possibility that selection acts directly on developmental processes themselves. Because plants grow and develop continuously throughout their lifetime, developmental processes are likely to be critical components of the functioning of these organisms and subject to selection. The alpine tundra presents a particularly intriguing environment in which to explore the results of natural selection on plant development. The alpine is a harsh environment with a very short growing season. Plants have a limited amount of time in which to develop, grow, and reproduce. A common pattern of development in many such environments is preformation. Plants form all structures used during any one growing season during the preceding growing season. These structures remain dormant and unexpanded during the winter and can expand and begin functioning rapidly in the spring. The alpine, however, is also an unpredictable environment. Patterns of snow drift and melt are variable from year to year, drought is common and varies with patterns of snow melt, and snow and freezing temperatures can occur at any time during the growing season. The most common pattern of plant development in such spatially and temporally varying environments is phenotypic plasticity (the ability of an individual to alter its phenotype and development). Thus, in the alpine, plants encounter two conflicting selective regimes both of which are expected to act directly on developmental processes. The short harsh season is expected to select for the predetermined pattern of preformation, while the unpredictability of the environment is likely to select for flexibility of development. These two patterns of development are in direct conflict: preformation is likely to limit any flexibility or developmental response to current environmental conditions. What, then, is the actual pattern of development that has evolved in response to these conflicting demands? The proposed research will examine the developmental properties of preformation and plasticity of plants in the alpine environment. The results will address the issue of the evolution of developmental processes and life histories, and can also be used to predict vegetation response to changing climatic conditions. The Colorado alpine is currently being studied as a model system for examining the effects of global change. Because the alpine is such a harsh and marginal environment, small climatic changes are expected to have dramatic effects on species distribution. A more thorough understanding of the range and limits of developmental responses of alpine plants to environmental variation will provide new and important information for models of vegetation change or persistence.

许多进化研究的基本假设是 发育过程中的进化变化 间接地，通过选择由那些 流程. 而字符之间的变化必然是 在潜在的发展过程中的变化，这是 这些角色的功能受到自然的影响， 选择. 发展结果的演变，但只有 因为这些过程产生了所选择的字符。 在 相反，进化的一个小方面是 选择直接作用于发育的可能性 过程本身。 因为植物在整个过程中不断生长发育 它们的一生，发育过程可能是至关重要的， 这些有机体的功能成分，并受到 选择. 高山冻土带呈现出一种特别有趣的 探索自然选择结果的环境 植物的发展。 阿尔卑斯山是一个恶劣的环境， 很短的生长季节。 植物的时间有限 在其中发育生长和繁殖 的常见图案 在许多这样的环境中的发展是预先形成的。 植物 形成在任何一个生长季节期间使用的所有结构， 在生长季节之前。 这些结构仍然处于休眠状态， 在冬季不会膨胀，可以膨胀并开始发挥作用 在春天迅速。 然而，阿尔卑斯山也是一个 不可预测的环境。 积雪漂移和融化的模式是 年复一年，干旱是常见的，并随着时间的推移而变化。 雪融化的模式，雪和冰冻的温度可以 在生长季节的任何时候都可以发生。 最常见的 在这样的空间和时间上的植物发展模式 不同的环境是表型可塑性（一个人的能力）。 个体改变其表型和发育）。 因此，在阿尔卑斯山，植物遇到两个相互冲突的 选择性的制度，这两个制度都被期望直接作用于 发展过程。 预计短暂的严酷季节将 选择预定的预成形模式，而 环境的不可预测性可能会选择 发展的灵活性。 这两种发展模式 直接冲突：预形成可能会限制任何 对当前环境的灵活性或发展反应 条件 那么，实际的发展模式是什么呢 是为了回应这些相互冲突的需求而进化的吗 拟议的研究将检查发育特性 阿尔卑斯山植物的预形成和可塑性 环境 结果将解决进化的问题 发展过程和生活史，也可以 用于预测植被对气候变化的响应 条件 科罗拉多高山目前正在研究作为一个 研究全球变化影响的模型系统。 因为 阿尔卑斯山是这样一个严酷的边缘环境， 预计气候变化将对物种产生巨大影响 分布 更深入地了解范围和 高山植物的发育反应限制 环境变化将提供新的和重要的 植被变化或持久性模型的信息。