Dissertation Research: Costs of Plasticity in Plant Defense: Sexual and Asexual Fitness Across Years

入侵杂草的一个特征可能有助于它们的成功，那就是它们主动应对食草动物的能力。因此，要想了解杂草的传播，需要研究这些被称为“诱导防御”的反应是如何进化的。虽然许多入侵的杂草可以活很多年，并可以通过地下茎无性繁殖，但以前关于防御进化的研究只测量了一年的有性繁殖(种子结实)。这个项目通过使用遗传分析来测量有性繁殖和无性繁殖，来研究杂草Solanum carolinense诱导防御的进化。在一年多的持续野外实验中已经测量了有性繁殖和防御；将在第二年使用微卫星DNA分析来确定这一实验的重新萌发，以量化繁殖。防御和组合繁殖之间的关系将表明诱导防御预计如何在自然种群中进化。这个项目将研究草食动物如何影响一种有毒杂草的进化和无性传播，这种有毒杂草也是几种重要经济害虫的宿主，包括科罗拉多州土豆甲虫。更好地了解杂草是如何成功的，对于更好地管理杂草和入侵物种是相关的。此外，该项目将为未来的研究开发遗传标记，并提供本科生研究培训。

One characteristic of invasive weeds that may contribute to their success is their ability to actively respond to herbivores. Understanding the spread of weeds therefore requires studying how these responses, called "induced defenses", may evolve. While many invasive weeds live for many years and can reproduce asexually through underground stems, previous studies of defense evolution have only measured sexual reproduction (seed set) over one year. This project examines the evolution of induced defenses in the weed Solanum carolinense by using genetic analysis to measure both sexual and asexual reproduction. Sexual reproduction and defenses have already been measured in an ongoing field experiment over one year; re-sprouts from this experiment will be identified using microsatellite DNA analysis to quantify reproduction in a second year. The relationship between defenses and combined reproduction will indicate how induced defenses are expected to evolve in natural populations.This project will address how herbivores affect the evolution and asexual spread of a noxious weed that is also a host for several economically important insect pests, including the Colorado potato beetle. Better understanding of how weeds succeed is relevant to developing better management of weeds and invasive species. Additionally, this project will develop genetic markers for future studies and provide undergraduate research training.