Genetic characterization, fungicide susceptibility, and aphicidal potential of Lecanicillium fungi from Argentina

MANFRINO ROMINA GUADALUPE; SCHUSTER CHRISTINA; TORNESELLO GALVÁN JULIETA; SAAR KATHARINA; GARCÍA JUAN JOSÉ; LÓPEZ LASTRA CLAUDIA CRISTINA; LECLERQUE ANDREAS

Mainz

Conferencia; International Conference on Invertebrate Pathology; 2014

Mitosporic fungi of the genus Lecanicillium (Ascomycota; Hypocreales) are of particular interest as biological control agents for phloem-sucking plant pests including aphids. Bioprospection for these fungi in Argentina has given rise to a set of single-spore derived Lecanicillium strains isolated from a wide range of original hosts. Current species delineation within the taxonomic genus Lecanicillium that consists of the three ?core species? Lecanicillium lecanii, L. muscarium, and L. longisporum as well as further less closely related species, is not free of ambiguity. For species-level characterization of Lecanicillium isolates, a set of five genetic markers comprising one mitochondrial (NMS) and two nuclear (ITS, IGS) ribosomal RNA operon together with one mitochondrial (nad1) and one nuclear (ef1) protein-encoding sequences, has been employed. The aggregated information from these markers indicates that fungal isolates from Argentina mainly, but not exclusively belong to the Lecanicillium core species. Moreover, the set of Lecanicillium strains has been investigated for fungicide sensitivity. Between strain differences in susceptibilities have been found to be important and not necessarily in line with systematics, making careful determination of sensitivity to agriculturally used fungicides an important criterion of biocontrol agent selection. However, the fungicidal polyketide compound soraphen has been found of outstanding activity against a wide variety of isolates from all species investigated. On the basis of these results, a subset of strains has been selected for virulence bioassays against the green peach aphid, Myzus persicae, an important agricultural pest in Argentina and other parts of the world.