DISSERTATION RESEARCH: Hybridization, Polyploidy and Pollinator Behavior in Indian Paintbrush (Castilleja).

这个项目的目标是了解杂交和多倍性如何串联影响自然种群中观察到的表型模式，以及传粉者的行为如何通过选择来加强这种模式。本研究探讨了3种共同出现的印度画笔。然而，在某些地方，杂交已经模糊了物种之间的形态差异，而在其他地方，物种似乎没有杂交，并保持表型独特。我们假设杂交发生在3个共存物种具有相同倍性水平的种群中。在其他植物系统中，物种之间倍性水平的差异可能会对繁殖造成障碍。将用AFLP标记对来自每种类型群体的重复的植物进行基因分型，并通过流式细胞术和染色体计数确定倍性水平。田间授粉实验将确定传粉者作为选择的媒介，是否有助于产生或加强观察到的模式。杂交和多倍性在大多数植物谱系的进化中起着重要作用，但这些过程和选择如何共同影响表型变异的景观格局却很少被研究。通过一起研究这两个过程，将更好地了解它们各自在不同植物谱系进化中的作用。

The goal of this project is to understand how hybridization and polyploidy, in tandem, influence observed phenotypic patterns in natural populations, and how pollinator behavior, through selection, reinforces such patterns. This study examines 3 species of Indian Paintbrush that co-occur. In some locations, however, hybridization has obscured morphological distinctions between the species while in other locations species do not appear to hybridize and remain phenotypically distinct. We hypothesize that hybridization occurs in populations where the 3 co-occurring species have identical ploidy levels. In other plant systems, differences in ploidy levels between species can create barriers to reproduction. Plants from replicates of each type of population will be genotyped with AFLP markers and ploidy level will be determined by flow cytometry and chromosome counts. Pollination experiments in the field will determine whether pollinators, as agents of selection, help produce or reinforce observed patterns. Hybridization and polyploidy have been instrumental in the evolution of most plant lineages, yet how these processes and selection together influence landscape patterns of phenotypic variability has rarely been studied. By studying these two processes together, a greater understanding of their respective roles in the evolution of diverse plant lineages will be achieved.