Collaborative Research: RUI: Introgression of Plant Resistance: Selection on Hybrid Willows by an Herbivorous Slug

摘要Colin M .Orians DEB-9981568 Robert S.弗里茨DEB 9981406塔夫茨大学 瓦萨学院合作研究RUI：植物抗性性状的渐渗：草食性蛞蝓对杂交柳树的选择和弗里茨将研究渐渗在适应进化中的重要性。 他们将检验这样一个假设，即由于食草蛞蝓的选择，适应性植物抗性性状在杂交杨柳基因型中可能受到青睐。 该系统是一对杂交的杨柳物种，具有广泛的同域分布范围，目前在整个重叠区，似乎已经经历了过去的基因渗入。 PI将从每个杨柳物种的纯亲本中产生F2后代，然后将这些后代中的一些通过引入的蛞蝓A.带条肌初步证据表明，蛞蝓的植食性和幼苗的死亡率与植物化学有关。第一个实验将测试蛞蝓食草动物是否会导致选择有利于具有较高浓度酚苷的F2表型。实验二将涉及确定的化学基础的选择性蛞蝓喂养F2代相比，父母。 对于实验3，PI将测量选择的和对照的F2后代对另外两种主要杨柳植食动物日本甲虫和杨柳叶锈病的抗性。 这将决定在F2中选择对蛞蝓具有更高抗性的物种是否有生态成本，或者对蛞蝓的抗性是否与对这些其他物种的抗性协同或独立。 实验4将包括两代回交和蛞蝓选择，以确定酚糖苷性状是否在回交中持续存在，并提高一些基因型相对于非选择回交对杨柳S的适合度。绒头类。 该实验将直接测试渐渗模型，并且将允许测试具有不同化学防御的渐渗植物之间的分配和生态成本。

Abstract Colin M .Orians DEB-9981568 & Robert S. Fritz DEB 9981406Tufts University Vassar CollegeCollaborative Research RUI: Introgression of Plant Resistance Traits: Selection on Hybrid Willows by an Herbivorous SlugOrians and Fritz will study the importance of introgression in the evolution of adaptations. They will test the hypothesis that adaptive plant resistance traits can be favored among hybrid willow genotypes due to selection by a herbivorous slug. The system is a hybridizing pair of willow species that have broadly sympatric ranges, currently hydridize throughout their zone of overlap and appear to have undergone past introgression. The PI's will make F2 progeny from pure parents of each willow species and then subject some of these progeny to herbivory by the introduced slug, A. fasciatus. Preliminary evidence suggests that slug herbivory and mortaility of seedlings is related to plant chemistry. The first experiment will test if slug herbivory causes selection favoring F2 phenotypes with higher concentrations of phenolic glycosides. Experiment two will involve determination of the chemical basis of selective slug feeding among F2 progeny compared to parentals. For Experiment 3, the PI's will measure the resistance of selected and control F2 progenies to two other major willow phytophages, Japanese beetles and willow leaf rust. This will determine if there are ecological costs of selection for higher resistance to slugs in F2's ,or, if resistance to slugs is synergistic or independent of resistance to these other species. Experiment 4 will include two generations of backcrossing and selection by slugs to determine if phenolic glycoside traits persist in backcrosses and improve the fitness of some genotypes relative to non-selected backcrosses to the willow S. eriocephala. This experiment will directly test the Introgression model, and will permit tests of allocational and ecological costs among introgressed plants with different chemical defenses.