DISSERTATION RESEARCH: Adaptation and historical ecology in vernal pool Eryngium (Apiaceae)

论文研究：春池刺蓟属（伞形科）的适应和历史生态学

• 批准号: 0909804
• 负责人: Bruce Baldwin
• 金额: $ 1.2万
• 依托单位: University of California-Berkeley
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-07-01 至 2012-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0909804&HistoricalAwards=false
• 关键词: DISSERTATION; RESEARCH; Adaptation; historical; ecology

Vernal pools are island-like depressions characterized by seasonal extremes: flooding during winter and desiccation during summer; they are home to many endangered plants and animals. In such habitats, plants and animals must possess extreme adaptations. Many species of Eryngium occupy Californian vernal pools; these plants are closely related to carrots and parsnips. In this study, adaptations in Eryngium will be viewed from a historical perspective. DNA sequences will be collected from related species of Eryngium from California, Oregon, and Chile -- some restricted to vernal pools and some from normal terrestrial habitats. Relationships between these plants will be reconstructed from their DNA sequences. This history will give insights into how a specific adaptation, seasonal changes in leaf form, may have arisen. In Eryngium, as well as other vernal-pool plants, two types of leaves are produced: (1) winter leaves, which are well suited to flooded environments but as a trade-off produce less energy than (2) summer leaves, which are poorly suited to winter flooding. An experiment will be conducted to determine if the shift from winter leaves to summer leaves is triggered by increases in the amount of daylight per day during spring, and to determine whether leaf development is tightly constrained by genetics or if it can respond adaptively to changing environmental conditions. An important question to biologists to be addressed is whether specialization of habitat is irreversible: If plants adapt to vernal pools, are they trapped by their success? Many species of Eryngium in the vernal pools of California are in peril, and an answer to this question along with improvements in the understanding of the life history of Eryngium will aid conservation efforts. The experiment in this study gives opportunity for underrepresented minorities to learn scientific research techniques otherwise not available to undergraduates.

春季池是类似岛状的凹陷，其特征是季节性极端：冬季洪水和夏季干燥；它们是许多濒临灭绝的动植物的家园。在这样的栖息地，植物和动物必须具有极端的适应性。许多种类的红斑占据了加利福尼亚的春季池；这些植物与胡萝卜和欧洲防风草密切相关。在这项研究中，将从历史的角度看待红细胞的适应。 DNA序列将从来自加利福尼亚州，俄勒冈州和智利的红细胞的相关物种中收集，其中一些仅限于春季池，有些则来自正常的陆地栖息地。这些植物之间的关系将从其DNA序列中重建。这段历史将有见识特定的适应性，叶形式的季节性变化可能会产生。在红细胞和其他春季植物中，产生了两种类型的叶子：（1）冬季叶子非常适合洪水泛滥的环境，但由于权衡的能量比（2）夏季叶子少，这些夏季叶子适合冬季洪水。将进行一个实验，以确定春季每天每天的日光增加是否会触发从冬季到夏季的转变，并确定遗传学是否受到遗传学的严格限制，还是可以适应不断变化的环境状况。 要解决的生物学家的一个重要问题是，栖息地的专业化是否不可逆转：如果植物适应春季池，它们是否被成功所困扰？加利福尼亚春季池中的许多红细胞都处于危险之中，对这个问题的答案以及对eryngium生活史的理解的改善将有助于保护工作。这项研究的实验为代表性不足的少数民族提供了学习科学研究技术的机会，否则本科生无法获得。