Dissertation Research: Phylogeny, Cospeciation, and Life History Evolution in the Cedar Apple Rust Fungi (Gymnosporangium, Pucciniaceae)

本研究探讨了雪松苹果锈病真菌的进化模式。这些寄生虫有一个复杂的生命周期，它们交替地生活在两种不同的植物上以繁殖。指导和制约雪松苹果锈病新种进化的因素尚不清楚。这项研究试图了解寄生虫进化的三个关键方面的重要性。它们是共种，即寄生虫与其寄主植物一起进化新物种，生命周期复杂性的进化，以及特定寄主物种的专业化程度。锈病致病菌在世界范围内对小麦、大豆和咖啡等重要作物造成重大损害。雪松苹果锈病尤其会对苹果、梨和榅桲等果树造成损害。新的和有毒的锈病物种的进化是特别值得关注的。这项研究将增加对锈病进化过程的认识，并对真菌与植物的关系和植物寄生的关系进行共种和性状分析。这项研究将包括日本和北美的雪松苹果锈病。与日本科学家建立的合作关系将有助于扩大和交流关于植物病原真菌的知识。

This study investigates evolutionary patterns in the cedar apple rust fungi. These parasites have a complex life cycle in which they alternately live on two different plant species in order to reproduce. The factors that direct and constrain the evolution of new species of cedar apple rust are not well understood. This study seeks to understand the importance of three crucial aspects of parasite evolution in this group. These are cospeciation, in which a parasite evolves new species in tandem with its host plant, the evolution of life cycle complexity, and the degree of specialization on particular host species.Rust pathogens cause major damage worldwide to such important crops as wheat, soybeans, and coffee. Cedar apple rusts in particular cause damage to fruit trees such as apples, pears, and quince. The evolution of new and virulent species of rusts is of particular concern. This study will increase understanding of evolutionary processes in rusts and the cospeciation and character analyses will have broad relevance in understanding fungal-plant relations and plant parasitism. The study will include Japanese as well as North American species of cedar apple rust. The collaborative ties with Japanese scientists that have been established will serve to promote the expansion and exchange of knowledge on plant pathogenic fungi.