XVI International Botanical Congess

DNA sequences from protein-encoding genes are useful for making inferences about species boundaries in fungi. Intraspecific variation can be used to identify recombining groups, whereas interspecific polymorphism can be used to identify reproductively isolated species units. Species can be defined as recombining groups of isolates that share fixed polymorphisms with respect to other such groups. Once these groups are defined, biological traits of interest such as toxin production and pathogenic potential may be correlated with species units. Three case studies in the genus Aspergillus will be discussed: 1.) identification of cryptic species in Aspergillus flavus, 2.) discovery of the A. flavus progenitor of the industrial fungus Aspergillus oryzae, and 3.) identification of the fungus that causes sea fan coral diebacks in the West Indies.