Investigating Genetic Diversity of Phytophthora spp. and Related Oomycetes

Oomycetes, like fungi, are filamentous heterotrophs, but unlike true fungi are diploid and share a photosynthetic ancestor. Many of these organisms are plant and animal pathogens, and members of the genus Phytophthora cause devastating disease on a diverse array of agricultural plant hosts. Several diverse topics in oomycete biology are investigated in this dissertation. Chapter 2 is a report on loss of heterozygosity in Phytophthora capsici in response to chemical mutagenesis.The research presented in Chapters 3 and 4 are centered on documenting biodiversity and genetic diversity of populations of Phytophthora species obtained from infected plant hosts. The final chapter (Chapter 5) involves determining genetic diversity, ecology, and enzymatic activities of Pythiaceous oomycetes from marsh wetlands of the southeastern US.