Dissertation Research: Speciation, Hybridization and Phylogeny of Pacific Coast Irises

太平洋沿岸的虹膜是由11种近缘关系密切的植物组成的群体。许多物种对在野外形成了可育的杂交种，这使它们成为研究物种形成的理想系统。这是一项研究三个自然产生的杂交区的建议，分析每个杂交区至少8个字符，以查看(1)字符的频率分布是否一致，以及(2)这些分布在杂交区内和杂交区之间的横断面上是否一致。为了补充这些变异模式的研究，将检查以下潜在的基因流动障碍：生境关联、开花时间、扩散速度和杂交种的适合度。根据形态和分子(cpDNA、rDNA、等位酶)特征的分支分析，杂交区的研究将放在整个蝴蝶科种群的系统发育的背景下进行。

The Pacific Coast Irises are a group of eleven closely related plant species. That many species pairs form fertile hybrids in the wild makes them an ideal system for the study of speciation. This is a proposal to study three of the naturally occurring hybrid zones, analyzing at least eight characters per hybrid zone, to see (1) if the character's frequency distributions coincide, and (2) if these distributions are concordant along transects within and between hybrid zones. To complement these studies of patterns of variation, the following potential barriers to gene flow will be examined: habitat association, flowering time, dispersal rate and the fitness of hybrids. The hybrid zone studies will be placed in the context of a phylogeny of the entire group of irises, relying on cladistic analysis of morphological and molecular (cpDNA, rDNA, allozymes) characters.