Dissertation Research: The Ecological Genetics of Autogamy in Arenaria uniflora

9623350 Stratton植物育种系统对个体繁殖的数量和质量起到过滤作用，并影响种群遗传结构、人口统计学和生态。反过来，生态因素和遗传交互作用都塑造了植物育种系统的进化。以往对植物交配系统进化的分析主要集中在遗传因素的作用上，对传粉生态在交配系统进化中的作用知之甚少。这个项目通过对自交和异交植物繁殖成功的实验比较来填补这一空白。以露头多形花岗岩为模式系统，进行了3个综合试验。首先，对自交和异交个体近亲繁殖衰退的分析将表明反对自交可育基因传播的力量。其次，使用标记等位基因的父子关系分析将衡量与自交相关的男性生殖成功的损失。第三，在传粉者稀少的情况下，自动自交在提供生殖保证方面的价值将被实验检验。研究结果将对不同生态条件下每种交配策略的成本和收益进行综合分析。这些信息将有助于预测种群对栖息地碎片化或其他形式的环境退化下传粉者丰度变化的反应。

9623350 Stratton Plant breeding systems act as filters on the quantity and quality of individual reproduction and influence population genetic structure, demography, and ecology. In turn, both ecological factors and genetic interactions shape the evolution of plant breeding systems. Previous analyses of plant mating system evolution have concentrated on the role of genetic factors and little is known about the role of pollination ecology in mating system evolution. This project fills that gap with experimental comparisons of the reproductive success of selfing and outcrossing plants. Using the polymorphic granite outcrop endemic Arenaria uniflora as a model system, three integrated experiments will be conducted. First the analysis of inbreeding depression in selfing and outcrossing individuals will indicate forces opposing the spread of self-fertile genotypes. Second, paternity analysis using marker alleles will measure the loss of male reproductive success associated with selfing. Third, the value of automatic selfing in conferring reproductive assurance under conditions of pollinator scarcity will be tested experimentally. Findings will provide an integrated analysis of the costs and benefits of each mating strategy under different ecological conditions. This information will be of value in predicting population responses to changes in pollinator abundances under habitat fragmentation or other forms of environmental degradation.