CRB: Pollen Mediated Genetic Rescue in Plant Metapopulations

9610496 McCauley该项目将使用植物白蝇子草作为模型系统来研究遗传因素如何影响种群的持久性。许多物种分布成许多小的当地种群，这是由于有利栖息地的斑块的自然分布，或者由于人类对景观的影响。小种群往往面临着灭绝的高概率，而物种的持续存在可能需要以抵消当地灭绝的速度建立新的种群。由于小的或最近建立的种群往往表现出近亲繁殖的有害影响，因此了解新形成种群的遗传特征是很重要的。 这项研究将询问最近建立的种群是否容易受到近亲繁殖的有害影响，以至于近亲繁殖影响种群的持久性。它还将询问通过花粉传播（基因流）从种群到种群的基因移动是否可以抵消近亲繁殖的影响。对自然种群和实验种群的研究表明，阿尔巴将处理这些问题。对自然种群的研究将利用遗传技术来测量由于花粉运动而使新基因进入新近建立的种群的速度。他们还将研究这种基因流形成的植物是否比它们的邻居更有活力。在其他实验中，S. alba将被创建，以研究在更受控的条件下花粉和近亲繁殖的基因流动的相互作用。总之，这些研究的结果应该有助于更全面地了解遗传和生态因素如何相互作用，以确定一个物种可以在给定的景观中持续存在的概率。

9610496 McCauley This project will use the plant Silene alba as a model system to investigate how genetic factors influence the persistence of populations. Many species are distributed into numerous small local populations owing to the natural distribution of patches of favorable habitat, or due to human impact on the landscape. Small populations often face a high probability of extinction, and the persistence of the species at large may require that new populations be founded at a rate that offsets local extinctions. Since small or recently established populations often display the harmful effects of inbreeding, it is important to understand the genetic characteristics of newly formed populations. This study will ask whether recently established populations are prone to the harmful effects of inbreeding such that inbreeding influences population persistence. It will also ask whether the movement of genes from population to population by pollen dispersal (gene flow) can offset the effects of inbreeding. Studies of both natural and experimental populations of S. alba will address these issues. Studies of natural populations will use genetic techniques to measure the rate at which new genes enter recently founded populations owing to pollen movement. They will also investigate whether plants formed by this gene flow are more vigorous than their neighbors. In other experiments artificial populations of S. alba will be created in order to investigate the interaction of gene flow by pollen and inbreeding under more controlled conditions. Taken together, the results of these studies should contribute to a more general understanding of how genetic and ecological factors interact to determine the probability that a species can persist in a given landscape.