The association of Pestalotia species with members of the leguminous tree genera Hymenaea and Copaifera in the neotropics

Species of Pestalotia (Deuteromycetes, Melancoiales) were isolated from leaves of species of the two related tropical resin-producing genera, Hymenaea and Copaifera (Leguminosae, Caesalpinioideae), which had been collected for systematic and ecological studies. As part of a long-term evolutionary study of tropical resin-producing trees, leaf sesquiterpenes have been used as chemosystematic characters and then assessed for possible defensive properties against fungi and insects. Leaf resins in species of Hymenaea and Copaifera apparently consist of the same suite of sesquiterpenes. The hypothesis that leaf resins play a role in defense against tropical fungal pathogens has been tested in laboratory experiments. The authors have investigated the occurrence of members of the fungal genus Pestalotia on species of Hymenaea and Copaifera throughout the wide neotropical range of these trees, and have made preliminary observations on fungal colonization in relation to the concentration of leaf sesquiterpenes.