Collaborative Research: The Evolutionary Consequences of Floral Display Size in a Self-Compatible Plant

Mitchell9903308在一株自交可育植物上同时开花的花的数量可能对繁殖成功有深远的影响。例如，有大屏幕的植物可能会有更多的传粉者造访，从而增加种子产量。然而，大型显示器也可能会带来巨大的成本。自花授粉的可能性更大，因为大型显示器促进了植物内传粉者的运动。如果出现近亲繁殖衰退，女性的生殖成功将受到影响。自花授粉也可能会减少花粉向其他植物的转移，从而降低雄性生殖的成功率。这个项目利用一种新的实验系统来测试这样的假设，即这些相互冲突的选择压力有利于中等大小的花卉展示的演变。猴花(Mimulus Ringens)的展示将在由遗传不同的个体组成的复制(克隆)种群中进行操作。这些阵列有助于明确衡量亲子关系和个体自交率。在共同的遗传背景上操纵花卉展示大小，可以检查花卉展示和其他特征如何相互作用，影响生殖成功。为了研究花卉展示如何在自然种群中进化，将在一个普通花园的田间条件下进行人工选择实验。这些实验将提供关于花卉展示的适应性意义的独特数据，并将加强我们对植物交配系统进化的理解。这项研究的结果还将对农业(育种作物以最大限度地提高产量)和保护生物学(使濒危物种在植物园中的繁殖成功最大化)具有重要意义。

Mitchell9903308The number of flowers blooming simultaneously on a self-fertile plant may have profound consequences for reproductive success. For example, plants with large displays may receive more pollinator visits, increasing seed production. However, large displays may also entail significant costs. Self-pollination is more likely, since large displays promote within-plant pollinator movements. If there is inbreeding depression, female reproductive success will suffer. Self-pollination may also decrease pollen transfer to other plants, reducing male reproductive success. This project utilizes a novel experimental system to test the hypothesis that these conflicting selection pressures favor the evolution of intermediate-sized floral displays. Monkeyflower (Mimulus ringens) displays will be manipulated in replicate (cloned) populations consisting of genetically distinct individuals. These arrays facilitate unambiguous measures of paternity and individual selfing rates. Manipulation of floral display size on a common genetic background allows examination of how floral display and other traits interact in affecting reproductive success. To examine how floral display may evolve in natural populations, an artificial selection experiment will be conducted under field conditions in a common garden. These experiments will provide unique data concerning the adaptive significance of floral displays, and will enhance our understanding of the evolution of plant mating systems. The results of this research will also have important implications for agriculture (breeding of crops to maximize yield) and conservation biology (maximizing reproductive success of endangered species in botanic gardens).