XVI International Botanical Congess

Successful lichen mycoparasites are not inhibited by the secondary compounds produced by their hosts. Recently we have discovered a new lichen pathogen from Maryland, Fusarium sp (NRRL 26803), that can enzymatically degrade at least one of these compounds, lecanoric acid. Based on 18s rDNA sequence data from Dr. Kerry O'Donnell, this lichenicolous Fusarium is a member of a small clade of entomogenous fungi including F. larvarum, F. coccidicola, and F. coccophilum. Our results show that the three entomogenous species do not degrade lecanoric acid, suggesting that this degradative activity arose only once and is associated with the lichenicolous habit. Comparisons of lichen tissue degradation, lichen cell wall solubilization, and hydrolytic enzyme production by these Fusarium species are consistent with this hypothesis.