Effectiveness of Endophytic Fungi from Baccharis dracunculifolia Against Sucking Insect and Fungal Pathogens

Abstract

Endophytic fungi are important mediators of ecological interactions with herbivores, other microorganisms, and plants. These fungi produce metabolites that may reduce or prevent damage caused by pathogens and herbivores on plants and exhibit extensive biological properties with agronomic and pharmacological potential. This chapter evaluated the antipathogenic and deleterious potential of extracts of three species of endophytic fungi (Aureobasidium pullulans, Preussia africana, and Xylaria arbuscula) commonly found in Baccharis dracunculifolia. The extracts, prepared from each of the three endophytic fungi, had different concentration (50, 25, 12.5, 7.5, 5.0, 2.5, 1.0, 0.5, and 0.25 mg mL⁻¹) and were tested on four phytopathogens (Botrytis cinerea, Colletotrichum acutatum, Penicillium digitatum, and Pestalotiopsis longisetula) and the major sap-sucking insect herbivore on B. dracunculifolia (Uroleucon erigeronensis). The extract of Preussia showed the highest inhibitory activity against the all tested pathogens, while the extracts of A. pullulans and X. arbuscula inhibited the growth of B. cinerea (50, 25, 12.5, 7.5 mg mL⁻¹). The deleterious enormous potential of the three extracts was also recorded against the aphid R. erigeronensis, showing 100% mortality of individuals at a concentration of 1 mg mL⁻¹. The characterization of the classes of secondary metabolites present in the extracts was performed using thin layer chromatography, having detected the presence of phenols and triterpenes in extracts of A. pullulans and X. arbuscula. Nonpolar components of P. africana extract were evaluated by gas chromatography, revealing the production of some important groups of fatty acids. These results indicate that these endophytic fungi from B. dracunculifolia have biological and economic significance that merit further investigation.