XVI International Botanical Congess

Lichenicolous fungi are fungi that colonize lichens. These fungi express different levels of pathogenicity and host specificity. Hobsonia christiansenii is a generalized virulent lichen pathogen, H. santessonii, a specialized non-virulent lichen pathogen, and H.mirabilis, a plant pathogen. We used molecular techniques to characterize pure cultures of Hobsonia, and their possible relatives Marchandiomycete corallinus and Illosporium carneum. Phylogenetic analyses of nuclear SSU rDNA reveal that Hobsonia is not monophyletic. In fact, Hobsonia mirabilis and M. corallinus are basidiomycetes, and H. christiansenii, H. santessonii and I. carneum are ascomycetes. Superficially similar lichenicolous fungi arose multiple times, which may explain their differences in specificity and virulence.