Collaborative Research: Hybrid Plants and Zones as 'Sinks' for Herbivores: A Model System for Integrating Ecology, Genetics and Physiology of a Plant Herbivore Interaction

植物杂交区是常见的，通常代表自然的 在这些实验中，植物的基因防御 混合在一起，是研究生态和 植物和食草动物的进化相互作用以及 抵抗机制。 这项研究将探讨如何胆汁 甜菜天疱疮选择寄主和对窄叶蚜的反应 棉白杨，胡杨，和天然杂交种， 弗里蒙特棉白杨，弗里蒙特三角叶杨。两组相互关联的 会被问到问题 第一个是关于生态， 这种相互作用的演变和传播将解决： 许多复制的河流排水系统是混合植物， 食草动物“下沉”的区域， 养活了大部分的害虫B.如果克隆（即树 及其无性后代）对蚜虫易感， 它也容易受到其他种类的食草动物如麋鹿的影响 和蛀木甲虫和c.是否存在着 易受感染的克隆能成功阻止食草动物 攻击抗性克隆，还是易感植物只是为了 作为它们攻击其他人的水库 第二个问题，解决耐药机制， 易感性问，a。成功开发了分子 基因技术（RFLPs）的这个系统，可以基因 标记抗性和/或敏感性，并筛选树木， 纯区和混合区中的抗性，B.因为个人 克隆可以是遗传嵌合体（即，同一事物的不同部分 树是遗传不同的）什么样的模式 杂合和纯宿主克隆之间的嵌合现象，以及它们是如何 与紧张的生长环境有关吗C.因为个别 克隆也可以是抗性的发育嵌合体（即， 同一树的不同分枝或同一无性系的树干 不同的阻力作为年龄的函数），如何杂交和纯 宿主的发育抗性不同，和d.因为 生理库源关系影响抗性 个体克隆的特征，它们在影响 个体克隆内的发育抗性模式。

Plant hybrid zones are common and often represent natural experiments in which the genetically based defenses of plants have been mixed and are ideal for examining the ecological and evolutionary interactions of plants and herbivores as well as the mechanisms of resistance. This study will examine how the gall aphid, Pemphigus betae, selects hosts and responds to narrowleaf cottonwood, Populus angustifolia, and natural hybrids with Fremont cottonwood, P. fremontii. Two interrelated sets of questions will be asked. The first concerning the ecology, evolution and biogeography of this interaction will address: a. over many replicate river drainage systems are hybrid plants and zones "sinks" for herbivores such that a few susceptible plants support most of the pest population?, b. if a clone (i.e. a tree and its asexually derived progeny) is susceptible to aphids, will it also be susceptible to other kinds of herbivores such as elk and woodboring beetles?, and, c. does the presence of extremely susceptible clones prevent herbivores from successfully attacking resistant clones or do susceptible plants simply serve as reservoirs from which they attack the rest of the population? The second question, to address the mechanisms of resistance and susceptibility asks , a. having sucessfully developed molecular genetic techniques (RFLPs) for this system, can the genes for resistance and/or susceptibility be marked and trees screened for resistance in the pure and hybrid zones, b. since individual clones can be genetic mosaics (i.e., different parts of the same tree are genetically different) what are the patterns of mosaicism between hybrid and pure host clones and how are they related to stressful growing conditions?, c. because individual clones can also be developmental mosaics of resistance (i.e., different branches of the same tree or trunks of the same clone vary in resistance as a function of age), how do hybrids and pure hosts vary in their developmental resistance?, and d. because physiological sink-source relationships affect the resistance traits of individual clones, are they also important in affecting patterns of developmental resistance within individual clones.