Dissertation Research: Natural Selection and Genetic Constraints on the Evolution of Tolerance to Herbivore Damage in Ipomoea purpurea

9701330 Rausher植物对食草动物的反应长期以来一直是生物学家感兴趣的问题。这一领域的大部分工作都集中在植物如何防御草食动物--植物的“抗性”上。然而，植物也可以容忍草食(即将草食对生产力的影响降至最低)。尽管植物对食草动物损害的耐受性可能会极大地改变生物学家对植物-食草动物相互作用的看法，但对耐受性的生态学或遗传学知之甚少。我们将利用田间试验和数量遗传学的方法研究常见的牵牛花对三种食草动物危害的耐受性。具体地说，我们将测量耐性的遗传变异，ii)表征耐性与包括抗性在内的其他生态重要性状之间的遗传关系，以及iii)测量耐性与植物生产力之间的关系。植物对食草动物的耐受性研究对农业具有重要意义。食草动物是现代农业中的一个主要问题，导致生产力损失，需要投入大量昂贵的、对环境有害的杀虫剂。开发对草食性更耐受的作物品系可以最大限度地减少消除食草动物害虫的需要，因此可能有助于更经济和更环境可持续的农业。这项研究将提供有关耐性的遗传学和生态学的重要信息，这对于评估植物耐性在农业系统中的作用是必要的。

9701330 Rausher The response of plants to herbivory has long been of interest to biologists. The majority of work in this area has focused on how plants defend themselves against herbivores - plant "resistance". However, plants may also tolerate herbivory (i.e. minimize the effect that herbivory has on productivity). Although plant tolerance to herbivore damage may dramatically alter how biologists think about plant-herbivore interactions, little is known about the ecology or genetics of tolerance. We will use field experiments and quantitative genetics to study the tolerance of the common morning glory, Ipomoea purpurea, to three types of herbivore damage. Specifically, we will i) measure genetic variation for tolerance, ii) characterize the genetic relationship between tolerance and other ecologically important traits, including resistance, and iii) measure the relationship between tolerance and plant productivity. The study of plant tolerance to herbivory may have important implications for agriculture. Herbivores are a major problem in modern agriculture leading to loss of productivity and requiring large inputs of expensive and environmentally harmful pesticides. Developing strains of crop plants that are more tolerant of herbivory may minimize the need to eliminate herbivore pests and therefore may contribute to more economically and environmentally sustainable agriculture. This study will provide important information on the genetics and ecology of tolerance which will be necessary for evaluating the role that plant tolerance may have in agricultural systems.