Long-lived individuals of the opportunistic fungal pathogen Armillaria gallica arise in single mating events, and then grow vegetatively to occupy large territories including multiple woody substrates. In effect, this leaves a spatial record of mutation, the detection of which would allow new inferences about how fungal individuals grow and infect their hosts. In this thesis, I first identified a large individual of A. gallica in eastern Ontario. I then searched for genetic variation within this individual by focusing on the tandemly repeated rRNA gene cluster and four microsatellite markers that are variable in the A. gallica population. I discovered a loss of heterozygosity (LOH) in the rRNA gene-cluster region, forming two genotypes that show significant spatial clustering in a Mantel test. My M.Sc. thesis research serves as a baseline for a genome-wide study of the mutational dynamic within the vegetative growth phase of this large and old Armillaria individual.

Long-lived individuals of the opportunistic fungal pathogen Armillaria gallica arise in single mating events, and then grow vegetatively to occupy large territories including multiple woody substrates. In effect, this leaves a spatial record of mutation, the detection of which would allow new inferences about how fungal individuals grow and infect their hosts. In this thesis, I first identified a large individual of A. gallica in eastern Ontario. I then searched for genetic variation within this individual by focusing on the tandemly repeated rRNA gene cluster and four microsatellite markers that are variable in the A. gallica population. I discovered a loss of heterozygosity (LOH) in the rRNA gene-cluster region, forming two genotypes that show significant spatial clustering in a Mantel test. My M.Sc. thesis research serves as a baseline for a genome-wide study of the mutational dynamic within the vegetative growth phase of this large and old Armillaria individual.