Dissertation Research: Phylogeny in the Genus Omphalina (Basidiomycota Agaricales) and the Evolutionary Consequences of Mutualism

9321828维尔加利认为，远亲生物之间的互惠关系可能导致新门的开始，并可能在植物对土地的殖民中发挥作用。支持这些假说的论点的高度推测性内容导致了许多争议。这个项目将通过研究担子菌属的一组真菌及其近缘种，对互惠关系的进化作用进行实证研究。这一组非常适合于互惠共生关系的进化研究，因为它包括密切相关的腐生(即非互惠共生)和互惠共生的物种(那些与藻类结合形成地衣的物种)，这表明向互惠共生状态的转变可能相对较新(Lutzoni和Vilgalys，1993)。在这项研究中，形态和分子特征将被用来推断该属物种之间的系统发育或相互关系，以及该属与其他类群的亲缘关系。这些最初的结果将被用来检验关于转变为互惠/地衣形成生活方式所涉及的特征的假设。这个模型系统将解决关于不同生物(在这种情况下，真菌和藻类形成地衣)可能相互作用而导致新的生命形式的重要问题。

9321828 Vilgalys It has been suggested that mutualistic associations between distantly related organisms can lead to the beginning of new phyla and may have been instrumental in the colonization of land by plants. The highly speculative content of the arguments supporting these hypotheses has led to much controversy. This project will undertake empirical studies of the evolutionary role of mutualism by studying a group of basidiomycete fungi, species in the genus Omphalina and its relatives. This group is well suited for evolutionary studies of mutualistic associations because it includes closely related saprophytic (i.e. non-mutualistic) and mutualistic species (those associating with algae to form lichens), suggesting that the transition to a mutualistic state might be relatively recent (Lutzoni and Vilgalys, 1993). In this study, both morphological and molecular characters will be utilized to infer the phylogeny or relationships of species of Omphalina to each other, as well as investigating the relationships of this genus to other groups. These first results will be utilized to test hypotheses concerning features involved in changing to a mutualistic/lichen forming life style. %%% This model system will address important questions concerning the possible mutualistic association of different organisms (in this case, fungi with algae to form lichens) leading to new life forms.